Category Archives: Uncategorized

Evaluation of the subtalar joint during gait using 3-D motion analysis: Does the STJ achieve neutral position?

by James M. Mahoney DPM1*, Eric So DPM1, David Stapleton BS2,3, Kevin Renner DPM1,2, Alayna Puccinelli DPM1,2, Vassilios Vardaxis2,3

The Foot and Ankle Online Journal 12 (1): 4

Background: One theory of hindfoot biomechanics claims that the subtalar joint (STJ) reaches neutral position during midstance, while another maintains that the STJ stays in an everted position throughout.  There is also evidence that STJ position during midstance changes with walking speed. The present study will compare four distinct STJ static positions to 3D kinematics of the STJ during self-selected and fast gait in over-ground level walking.
Methods: The right lower leg of 20 male participants was placed in three clinically used subtalar joint neutral static positions using biomechanical examination: SJNR (STJ neutral by calculation method), SJNP (STJ neutral by palpation method), NCSP (neutral calcaneal stance position), as well as in the resting bilateral standing posture RCSP (resting calcaneal stance position).  An eight-camera 3D motion capture system was used to capture and analyze the kinematics of the ankle complex during self-selected and fast walking conditions, as well as, the four static postures.
Results: The 3D subtalar joint movement pattern did not coincide with any of the three subtalar joint neutral positions (SJNR, SJNP and NCSP) during the midstance phase of self-selected or fast walking. Specifically, the subtalar joint remained in a significantly more everted and abducted position with greater deviations from neutral under the fast-walking condition.
Conclusions: None of the clinically used STJ neutral positions agree with the 3D pattern of the STJ during self-selected and fast gait. These results have implications related to clinical practice and the use of the STJ neutral position for evaluation and treatment purposes.    

Keywords: subtalar joint, biomechanics, gait

ISSN 1941-6806
doi: 10.3827/faoj.2018.1201.0004

1 – College of Podiatric Medicine and Surgery, Des Moines University, Des Moines, IA, United States
2 – Human Performance Laboratory, Des Moines University, Des Moines, IA, United States
3 – Department of Physical Therapy, Des Moines University, Des Moines, IA, United States
* – Corresponding author: James.Mahoney@dmu.edu


One of the prevailing concepts of STJ function was first advocated by Root [1].  He described his theory of subtalar joint neutral during walking as follows: “Shortly before heel lift, the subtalar joint reaches its neutral position.  During the remaining midstance period, the subtalar joint continues to supinate, and the rearfoot moves into a supinated position.” The validity of Root’s observation of subtalar joint neutral position, however, has been questioned in the biomechanics literature [2]. McPoil and Cornwall published a study in 1994, where they determined the pattern of the rear foot motion on the frontal plane during gait and compared it to the subtalar joint in the neutral position [3]. Contrary to Root’s theory, their findings concluded that the neutral position of the rearfoot during stance more closely resembled the resting calcaneal stance position than subtalar joint neutral position.  

Pierrynowsi et al. questioned the 2-D motion capture used by McPoil and Cornwall as describing the relative rear foot frontal plane motion accurately for only the first 4-36% of the gait cycle, and determined that 3-D motion capture was required to properly assess STJ motion during gait [4].  Pierrynowski et al. improved motion capture methodology and also concluded that the rearfoot did not achieve subtalar neutral position during the stance phase in gait. However, in their study, motion capture of the rearfoot, was taken while subjects walked at a slow speed on treadmill set at 0.89 meters/seconds the same for all subjects. The treadmill as the walking surface seems to affect foot motion during gait and as such it may alter the true rearfoot kinematics during the stance phase of gait [5].

Walking speed itself may also influence STJ position. Tulchin et al [6] findings concluded that when evaluating foot kinematics during gait it was imperative to account or control for walking speed because of the changes that occur with sagittal plane motion in the foot as walking speed increases; namely, an increase in plantarflexion of both the hindfoot and forefoot.  Rosenbaum et al [7] showed that with increasing walking speed there was also an increase in pronation. However, both Torburn and later Dubbledam showed that rearfoot motion in the frontal plane was not influenced by walking speed [8,9].

To further understand the function of the STJ during gait, we compared the 3D subtalar position during the midstance phase of gait at self-selected and fast walking speeds on a level walkway to three common clinically used subtalar joint neutral positions and the resting bilateral stance.

MATERIALS AND METHODS

Subjects

Twenty unimpaired, healthy adult male subjects volunteered to participate in the study (age 24.7 ± 1.7 years; mass 79.3 ± 12.0 kg; height 180 ± 7 cm). Inclusion criteria consisted of subjects who were active adults, free from injury over the last year, able to ambulate barefoot without the need for assistive devices, without any lower extremity/foot malalignment or had use of arch supports, shoe pads or foot orthoses. The study was reviewed and approved by the Institutional Review Board.

Experimental protocol

The subtalar joint neutral position is defined in three different ways.  Two involve non-weight bearing measurements: one by mathematical calculation and the second by palpation. The third way is in a weight bearing bilateral stance position.  In our study, we refer to the non-weightbearing mathematical calculation as SJNR (subtalar joint neutral by range of motion). Root provided a detailed explanation of how to find the subtalar neutral position in the non-weight bearing position which involved establishing the total range of motion for inversion and eversion followed by calculations with a formula he provided  which calculated the neutral position as 1/3 of the total range of subtalar joint inversion and eversion from the maximally everted position [10]. The second non-weightbearing STJ neutral position method employs a palpatory technique which we refer to as SJNP (subtalar joint neutral by palpation). This technique was not originally advocated by Root, but instead was adapted and modified over time based on Root’s principles. It involves palpating for the congruency of the talar head [11].   This SJNP technique is like that employed by McPoil and Pierrynowski [3, 4]. The third STJ neutral position is weight bearing NCSP (neutral calcaneal stance position). Root described it as follows: with the subject weightbearing in the normal angle and base of gait, the clinician “palpates the congruity of the medial and lateral edges of the talus in relationship to the calcaneus at the subtalar joint”, in addition to making sure “the concavity of the lateral surface of the foot is parallel to the concavity on the lateral surface of the leg”, and finally that “the lateral surface of the foot describes a straight line in the area of the calcaneocuboid joint” [12].  This technique has been modified over time so that it is most commonly measured by palpating for congruency of the medial and lateral aspects of the talus with the patient standing in the normal angle and base of gait [11]. Root also provided a technique for measuring the frontal plane position of the calcaneus, in the relaxed bilateral stance position, relative to the weightbearing surface which requires one to stand “in normal angle and base of gait” [12]. In the present study, this method is referred to as RCSP (relaxed calcaneal stance position) [See Table 1].

Data collection commenced after obtaining consent from each subject. First a clinical/biomechanical exam was performed on each subject bilaterally. During the clinical/biomechanical exam, subjects’ feet were inspected for any visible deformities and standard goniometric measurements were taken for the subtalar joint inversion, eversion range of motion (ROM), as well as the subtalar varus/valgus angle at each of the SJNR, SJNP, NCSP, and RCSP static positions (in random order), using frontal plane bisection lines of the posterior calcaneus and distal shank, according to Root’s protocol [10,12]. At the completion of the clinical exam, disposable, adhesive, radiopaque skin markers (2.0 mm pellets) were attached along the bisection line of the calcaneus and distal shank (0.33 mm diameter line), as well as the sustentaculum tali and the peroneal tubercle. Posterior and lateral x-rays were taken, and the relative locations of the radiopaque markers were used along with palpation for accurate skin adhered motion analysis marker placement for better bone alignment representation purposes.

The 3D rear foot joint angles at the four static positions and the average 3D rear foot joint angles over the midstance phase for the two different gait speeds were compared in this study. Two trials for each of the standing (RCSP and NCSP) and prone (SJNR and SJNP) static positions were collected prior to the walking trials. Each static trial captured consisted of three seconds while the positions described above were maintained. The gait speeds were self-selected typical and self-selected fast barefoot walking on a level grade walkway. The subjects were asked to walk first at their preferred typical self-selected speed (SSG) and then at a self-selected faster speed (FWS). Five successful gait trials per speed condition were captured after familiarization with the laboratory environment. A trial was deemed successful if the subject’s right foot completely contacted one of the force plates, while the subject did not adjust his step pattern. The average self-selected typical gait speed was 1.27 ± 0.11 m/s, with an average stride length of 1.38 ± 0.09 m, cadence of 109.6 ± 5.8 steps/min, and stance phase duration of 60.9 ± 1.4 % of the gait cycle. The respective gait parameters for the self-selected fast gait were the following: gait speed of 1.70 ± 0.20 m/s, with an average stride length of 1.82 ± 0.12 m, cadence of 124.9 ± 11.1steps/min, and stance phase duration was 58.7 ± 1.7 % of the gait cycle.

The shank (including tibia and fibula) and the calcaneus segments were assumed to be rigid and were tracked in the laboratory reference frame using retro reflective markers (7.9 mm diameter) adhered to the skin at specific anatomical landmarks to construct the respective segmental anatomical reference frames. Specifically: for the shank, markers were placed on the tip of the lateral malleolus (LM), the tip of the medial malleolus (MM), the tip of the fibular head (FH), and the top and bottom of the shank bisection line (TSB) and (BSB), respectively. For the hind foot, markers were placed at the top and bottom of the calcaneus bisection line (TC) and (BC) respectively, the lateral apex of the peroneal tubercle (PT), and the medial apex of the sustentaculum tali (ST).  Redundant markers on the shank and calcaneus were placed in the following places for tracking purposes: top and bottom lateral shank (TSL) and (BSL), along the line of the lateral epicondyle of the knee and the lateral malleolus; top and bottom tibia (TT) and (BT) on the medial surface; and the medial and lateral aspect of the calcaneus (MC) and (LC) on a transverse plane passing through the midpoint between TC and BC with the subject standing in the RCSP position. In addition, a toe marker was placed on the second metatarsal head (SMH), which was used as a guide to identify the midpoint between the posterior calcaneus markers TC and BC, at which level the MC and LC were placed, using a laser level during RCSP standing static position. The entire marker set was used for the two standing static positions (RCSP and NCSP), as well as a standing static reference position with the feet at shoulder width apart parallel to each other. The MM, PT and ST markers were removed and were created virtually for the two prone static positions and the dynamic gait captures.

Given the above marker placement, the anatomical reference frames were defined: (1) right shank; the frontal plane was defined by the mid-malleolus point MMP (mid-point between the MM and LM), the LM and the FH; the sagittal plane orthogonal to the frontal, containing the MMP and the mid-shank point MSP (mid-point between the TSB and BSB); the transverse plane for the shank was mutually perpendicular to its frontal and sagittal planes, (2) right hind foot (calcaneus); the sagittal plane was defined using the TC, BC and the midpoint between the MC and LC; the transverse plane orthogonal to the sagittal, containing the midpoints of the TC and BC, and the MC and LC; the frontal plane for the hind foot was mutually perpendicular to its sagittal and transverse planes.

The three-dimensional joint angles of the calcaneus with respect to the shank (representing both the subtalar and the talocrural joints) were calculated using Cardan angles. The sequence of rotations used was sagittal (plantarflexion (-) / dorsiflexion (+)), frontal (eversion (-) / inversion (+)), and then transverse (abduction (-) / adduction (+)) plane [13].   

The kinematics data was collected at 120 Hz, using an eight-camera motion capture system (Motion Analysis Corporation, Santa Rosa, CA). Ground reaction force data was collected at 1200 Hz using three force plates (AMTI, Watertown, MA) mounted flush with the walking surface and aligned in the direction of walking. A 10 N threshold for the vertical component of the ground reaction force (GRF) was used to determine the stance phase of the gait cycle (heel contact to toe-off).

To remain consistent with Root’s theory that “shortly before heel lift, the subtalar joint reaches its neutral position”, the midstance phase is operationally defined here as the portion of the stance phase were the foot is flat on the ground from the instant of toe-down to the instant of heel-off. This is consistent with the “Ankle Rocker” definition of Jacquelin Perry where the foot is plantigrade with foot-flat support [14]. The timing of the toe-down and heel-off events were determined using a simple algorithm of threshold crossings of the vertical coordinate of the toe (SMH) and virtual heel (midpoint of TC and BC) markers relative to the average height of these markers during the RCSP static position. Specifically, the toe-down event was identified as the frame following the negative crossing when the vertical coordinate of the SMH marker crossed its respective level of the static RCSP position, and the heel-off event was identified as the frame prior to the positive crossing were the vertical coordinate of the virtual heel marker crossed its respective level plus 3mm higher than the static RCSP position. The plus 3mm level adjustment was needed for consistent event detection to account for the decompression of the heel pad.  

One-way repeated measures ANOVA design was used to test for differences in the subtalar joint position across all four static conditions and the mean STJ position during midstance for SSG and FWS gait for each of the 3D planes (at α < 0.05). A set of a priori comparisons were performed to test for significant differences in STJ position between gait and each of the 4 static conditions, controlling for Type I error with a Bonferroni adjustment by setting the alpha (α) level to 0.05/4 = 0.0125. Paired t-test procedures were used to test for subtalar joint position differences between SSG and FWS gait (at α < 0.05).  The Statistical Package for the Social Sciences (SPSS Version 24.0, Chicago, IL) was used for all data analysis.

RESULTS

The three-dimensional angles of the calcaneus with respect to tibia during the stance phase of gait are shown in Fig. 1. Specifically, the average kinematic curve patterns of an individual subject are shown for the (a) sagittal, (b) frontal, and (c) transverse planes along with his five individual trials during typical self-selected (SSG) walking speed. In the sagittal plane, the three functional arcs are visible starting with the plantarflexion motion of the calcaneus with respect to the tibia approximately until the toes are down (TD). This plantarflexion action is followed by a prolonged dorsiflexion arc where the tibia moves forward on the plantigrade foot, as the load on the foot moves towards the forefoot, and continues this dorsiflexion action beyond heel-off (HO). The final arc is a rapid motion of the calcaneus with respect to the tibia in the plantarflexion direction, probably due to high forces produced by the triceps surae during propulsion.  

In the frontal plane, the calcaneus remains in a relatively fixed inverted position until toe-down, followed by an eversion arc while the foot is plantigrade well beyond the heel-off, and during the latter part of the stance we see a rapid relative inversion motion until toe-off.

Figure 1 Exemplar single subject temporal profiles (5 trials and mean), of the three dimensional angles of the calcaneus with respect to tibia during stance phase of self-selected speed gait. (a) to (c) represent the sagittal, frontal and transverse planes, respectively. The midstance phase is identified between toe-down (TD) and heel-off (HO). Thin dashed lines denote individual trials (N=5), thick solid line is the average pattern.  

The transverse plane motion is characterized by two arcs, a rapid initial abduction until toe-down followed by a gradual prolonged adduction that lasts until toe-off. Overall, there was no difference in the shape of the kinematic curve patterns between trials, subjects, and walking speeds (Figure 1).

The calcaneus to tibia average midstance phase angles show the subtalar joint for the fast gait condition (FWS) in significantly greater dorsiflexion (p=0.026) and eversion (p=0.000) position relative to the self-selected (SSG) gait condition (Table 2).  

The one-way repeated measures ANOVA reveal significant differences in all three planes across all the static positions and the dynamic gait conditions (p<0.000). The calcaneus is in a significantly greater inversion (Figure 2) and adduction (Figure 2) position for all three subtalar neutral positions (NCSP, SJNP and SJNR) as related to the average midstance phase position during typical (SSG) and fast walking speed (FWS) gait. The non-weight bearing subtalar neutral joint positions (SJNP and SJNR) place the subtalar joint in a significantly greater plantarflexion position relative to the average subtalar joint position during the midstance phase of both SSG and FWS gait. The weight bearing subtalar neutral position (NCSP) places the subtalar joint in a significantly greater dorsiflexion position relative to the self-selected gait position (Figure 2).

The calcaneus to tibia joint position during the resting calcaneal stance position (RCSP) showed no differences with the average midstance phase position of the subtalar joint during either one of the gait conditions (SSG and FWS) on the sagittal plane (Figure 2). While the calcaneus was found to be everted and adducted with respect to the tibia during the RCSP static position which is consistent with the average midstance phase position during gait, it showed significantly less eversion and adduction angles (Figure 2).    

DISCUSSION

In the current study, we compared the average midstance position (toe-down to heel-off) of the STJ to the resting calcaneal stance position and the three STJ neutral positions: calculation by taking 1/3 of the total range of STJ motion from the maximally everted position (SJNR), palpation of the medial and lateral sides of the talar head non-weight bearing (SJNP), and neutral calcaneal stance position (NCSP).  Our data showed that the STJ during midstance in gait was everted and abducted relative to these three STJ neutral positions. We also found that eversion and adduction of the calcaneus in relation to the tibia increased during fast walking speed.

The protocol that we followed to measure the movement of the STJ during gait is based on the work of Leardini et al [15] who demonstrated that dynamic foot function is best measured by considering the foot as a multisegment structure, rather than a single, rigid body.  Furthermore, Tulchin [6] showed that increased walking speed changes the foot kinematics assessed using a multisegment foot model which led us to the protocol to evaluate the STJ motion during both self-selected and fast-walking gait.  

Figure 2 Group means (S.D.) of the calcaneus with respect to tibia angles (º), of the average midstance phase of the self-selected (SSG) and fast walking (FWG) speed gait, and the four static conditions (RCSP, NCSP, SJNP, and SJNR) for: (a) sagittal, (b)  frontal, and (c) transverse plane. Bonferroni adjusted significant differences ( p<0.0125) between SSG and FWG for each of the static conditions are denoted by * and † respectively.

Contrary to Root [1], our data showed that the STJ was in a relative everted throughout the midstance portion of gait, rather than achieving neutral position, in agreement with McPoil [3] and Pierrynowski [4], despite their methodological limitations of 2D analysis and fixed low walking treadmill speed, respectively.  

Recently, Buldt et al. [18] showed that clinical static foot postural and mobility measures can explain only a small amount of variation seen in foot kinematics during walking amongst asymptomatic individuals. Their data suggests that the clinical practice measures of foot posture (such as the STJ neutral) and mobility have limited application to foot function during dynamic tasks.   

One of the major points of contradiction between the work of Root and others regarding STJ neutral position during gait is probably due to Root’s misinterpretation of previously published data. Sobel and Levitz [16] maintain that Root developed his theories of STJ neutral from the work of Wright [17].  In his study, what Wright referred to as the RCSP, Root interpreted as STJ neutral. Whether it was the RCSP or neutral position that was described by Root, our data showed that the actual position of the STJ during gait was everted to both.

Measuring the neutral position of the STJ in a static position has been critical in clinical practice for predicting the “ideal” position of the foot as it functions during gait.  Root advocated that STJ neutral was the most stable position of the foot during gait [1], and therefore, foot pathology occurs when there is deviation from this “ideal” neutral position.  This applies to the fabrication of foot orthoses, when casts of the feet are taken in either static non-weight bearing or weightbearing STJ neutral position.

While our data showed a significant discrepancy between the static relaxed and the STJ neutral position(s) commonly used in clinical practice against the average dynamic STJ during the midstance phase of gait, there is a substantial concern in the literature related to the lack of STJ neutral position intra- and inter-rater reliability. According to Pierrynowski , experienced practitioners were within ±1° of the subtalar joint non-weight bearing neutral position only 41.3% of the time (within ±3°, 90% of the time)[19].  In Van Gheluwe et al’s study, five experienced podiatric physicians showed a high intra-rater reliability when measuring STJ pronation and supination, NCSP, and RCSP but very poor inter-rater reliability except for RCSP [20]. Elveru reviewed the literature concerning the non-weight bearing measurement of subtalar joint neutral position and subtalar joint passive range of motion and concluded that “their reliability is less than optimal [21].” Open and closed kinetic chain measurement of STJ neutral yielded poor intra-rater and inter-rater reliabilities when performed by two inexperienced testers, according to Picciano [22].  Smith-Oricchio found that measurements of calcaneal inversion and eversion and STJ neutral had low to moderate inter-rater reliability [23].

CONCLUSIONS

Our study has shown that the STJ during midstance in gait was more everted and abducted relative to all three STJ neutral positions performed under weightbearing or non-weight bearing conditions. This discrepancy between the STJ position during gait and the STJ neutral positions brings into question the clinical practice use of the STJ neutral position to determine the “ideal” functional position for the foot, as well as its use for orthosis prescription purposes.

Conflict of Interest

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article:  Des Moines University College of Podiatric Medicine and Surgery.

Abbreviation Definition Load
RCSP Relaxed calcaneal stance position Weight Bearing
NCSP Neutral calcaneal stance position Weight Bearing
SJNP Subtalar joint neutral by palpation Non-weight Bearing
SJNR Subtalar joint neutral by range of motion Non-weight Bearing

Table 1 Abbreviations, definitions and load conditions for the neutral and relaxed subtalar static positions of the foot.

Variable Self-selected speed gait (SSG) Fast walking speed gait (FWS)
Mean ± SD 95% CI Mean ± SD 95% CI t p
Sagittal Plane – DF:(+) -0.44 ± 2.35 -2.66 to 5.29 0.22 ± 2.80 -2.22 to 7.48 2.41 .026
Frontal Plane – IN:(+) -3.80 ± 1.66 -6.56 to -1.39 -4.80 ± 2.10 -9.57 to -1.95 4.46 .000
Transverse Plane – AD:(+) -3.51 ± 1.53 -6.31 to -0.75 -4.17 ± 2.17 -8.36 to -1.07 1.99 .061

Table 2 Calcaneus to tibia during midstance (toe down to heel off) average position parameters during gait. Mean, standard deviation, and 95% confidence interval for typical and fast self-selected walking speeds. Differences with walking speed: t-statistic and p values are shown.  

REFERENCES

  1. Root ML, Orien WP, Weed JH, et al: “Normal Motion of the Foot and Leg in Gait,” in Biomechanical Examination of the Foot, Vol 2, p. 127, Clinical Biomechanics Corporation, Los Angeles, 1971.
  2. Levitz SJ, Sobel E. The root controversy.  Podiatry Management 1997 Sept;16:61-67.
  3. McPoil TG , Cornwall MW. Relationship between neutral subtalar joint position and pattern of rearfoot motion during walking.  Foot Ankle Int 1994 Mar;15(3):141-145.
  4. Pierrynowski MR, Smith SB. Rear foot inversion/eversion during gait relative to the subtalar joint neutral position. Foot Ankle Int 1996 Jul;17(7):406-412.
  5. Barton CJ, Kappel SL, Ahrendt P, Simonsen O, Rathleff.  Dynamic navicular motion measured using a stretch sensor is different between walking and running, and between over-ground and treadmill conditions.  J Foot Ankle Res 2015;8:5.
  6. Tulchin K, Orendurff M, Adolfsen S et al. The effects of walking speed on multisegment foot kinematics in adults.  J Appl Biomech 2009;25:377-386.
  7. Rosenbaum D, Hautmann S, Gold M, Claes L. Effects of walking speed on plantar pressure patterns and hindfoot angular motion.  Gait Posture 1994 Sept;2:191-197.
  8. Torburn L, Perry J, Gronley J.  Assessment of rearfoot motion: passive positioning, one-legged standing, gait. Foot Ankle Int 1998 Oct;19(10):688-693.
  9. Dubbledam R, Buurke JH, Simons C, Groothuis-Oudshoorn CGM, Baan H, Nene AV, et al.  The effects of walking speed on forefoot, hindfoot, and ankle joint motion. Clin Biomech 2010; 25:796-801.
  10. Root ML, Orien WP, Weed JH, et al: “Subtalar Joint,” in Biomechanical Examination of the Foot, Vol 1, p. 36, Clinical Biomechanics Corporation, Los Angeles, 1971.
  11. Sarrafian SK. Functional characteristic of the foot and plantar aponeurosis under tibiotalar loading. Foot Ankle 1987 Aug;8(1):4-18.
  12. Root ML, Orien WP, Weed JH, et al: “Static Stance Examination,” in Biomechanical Examination of the Foot, Vol 1, p. 116, Clinical Biomechanics Corporation, Los Angeles, 1971.
  13. Wu G, Siegler S, Allard P, Kirtley C, Leardini A, Rosenbaum D, et al. ISB recommendation on definitions of joint coordinate system of various joints for the reporting of human joint motion—Part I: ankle, hip, and spine. J Biomech 2002 Apr;35(4):543-548.
  14. Perry J, Burnfield JM: Gait Analysis: Normal and Pathological Function, 2nd ed., SLACK Incorporated, Thorofare, NJ,  2010.
  15. Leardini A, Benedetti MG, Berti L, Bettinelli D, NativoR, Giannini S.  Rear-foot, mid-foot, and fore-foot motion during the stance phase of gait. Gait Posture 2007 Mar;25(3):453-462.
  16. Sobel E, Levitz SJ.  Reappraisal of the negative impression cast and subtalar joint neutral position.  J Am Podiatr Med Assn 1997 Jan;67(1):32-33.
  17. Wright DG, Desai SM, Henderson WH.  Action of the subtalar joint and ankle joint complex during the stance phase of walking.  J Bone Joint Surg 1964 Mar;46A:361-382.
  18. Buldt AK, Murley GS, Levinger P, Menz H, Nester J, Landorf KB. Are clinical measures of foot posture and mobility associated with foot kinematics when walking?  J Foot Ankle Res 2015 Nov; 8:63.
  19. Pierrynowski MR, Smith SB, Mlynarczyk JH: Proficiency of foot care specialists to place the rearfoot at subtalar neutral.  JAPMA 1996 May;86(5):217-223.
  20. Van Gueluwe B, Kirby KA, Roosen P, Phillips RD.  Reliability and accuracy of biomechanical measurements of the lower extremities.  JAPMA 2002 Jun;92(6): 317-326.
  21. Elveru RA, Rothstein JM, Lamb RL, Riddle DL.  Methods for taking subtalar joint measurements. Phys Ther 1988 May;68(5):678-682.
  22. Picciano AM, Rowlands MS, Worrell T: Reliability of open and closed kinetic chain subtalar joint neutral positions and navicular drop test.  J Orthop Sports Phys 1993 Oct;18(4):553-558.
  23. Smith-Oricchio K, Harris BA: Interrater reliability of subtalar neutral, calcaneal inversion and eversion.  J Orthop Sports Phys 1990;12(1):10-15.

Initial experiences with clinical assessment of plantar tissue hardness in diabetes: A brief case series

by Joshua Young BSc.(Hons), MBAPO1,2*

The Foot and Ankle Online Journal 12 (1): 2

Plantar tissue assessment is important in the management of diabetic foot problems. As clinical assessment of plantar tissue hardness typically relies on palpation and observation only, durometer assessment is a potentially useful and feasible addition. This brief case series reports on initial experiences with the use of plantar tissue hardness measurement in 5 patients, together with plantar pressure measurement data. The results suggest some relationship between tissue hardness and peak plantar pressures (PPPs) at the forefoot. The data may suggest cut-off values, with forefoot tissue hardness <40 predicting safe PPPs and tissue hardness 60+ predicting dangerous PPP. However further research would be required to clarify these initial findings. Use of a durometer was found to be feasible within a clinical setting, and some initial data for comparison is provided. While assessment of plantar tissue hardness alone is unlikely to be a singular value which can guide treatment, it may offer a helpful addition to existing clinical assessments.

Keywords: diabetes, tissue hardness, durometer, tissue assessment, pressure

ISSN 1941-6806
doi: 10.3827/faoj.2018.1201.0002

1 – Roehampton Rehabilitation Centre, Queen Mary’s Hospital. St George’s University Hospitals NHS Foundation Trust
2 – Orthotist, Opcare, Oxfordshire, UK.
* – Corresponding author: joshua.young1@nhs.net


Foot ulcers are a major source of morbidity in diabetes [1]⁠. Risk factors for the development of foot ulcers include peripheral arterial disease, neuropathy and foot deformity [2,3]. Limited joint mobility⁠ and altered plantar tissue characteristics have also been shown to increase risk of ulceration [3, 4]. Plantar tissues in diabetes may become thinner, stiffer⁠ and harder [5, 6, 4]⁠.

Plantar tissue hardness can be measured relatively easily using a durometer and this has been explored in experimental studies, including studies of people with diabetes [4,7,8]⁠. Given that clinical assessment of plantar tissues typically relies on palpation, observation and subjective judgement only, the addition of durometer assessment is potentially helpful. This brief case series reports on initial experiences with the clinical use of plantar tissue hardness measurement, together with plantar pressure measurement data.

Methods

Skin hardness was measured with a durometer using the Shore O scale. The patient was positioned in supine and the durometer was applied perpendicularly to the foot for 3 seconds before taking the reading. Selected peak plantar pressures (PPP) were also recorded as part of the assessment, using the Pressure Guardian system (Tillges technologies, USA). Plantar pressures were recorded during walking at self-selected pace, with the subject wearing their usual shoes with a 3.2mm grey poron 4000 polyurethane inlay (Algeos, UK) only inside the shoe, in line with the department’s protocol. Recorded PPP were compared to the 200kPa threshold, which has been tentatively proposed as a dangerous level of pressure [9]⁠. Patients gave written informed consent for use of the information in this article.

Case 1

Subject 1 is a 60-year old male with type 2 diabetes and a left sided trans-tibial amputation. The remaining right foot has a history of ulceration at the interphalangeal joint of the hallux only, and the foot has been intact for over 1 year. The plantar tissues appeared in good condition except a small area of discolouration at the 1st metatarsal-phalangeal joint (MPJ), representing a small ‘blood blister’. Plantar tissue hardness was tested at the heel and all MPJs (Figure 1) and ranged between 28 – 41 shore O. PPP were measured at MPJs 1 and 3 in addition to the heel. Only the heel exceeded 200kPa (Table 1).

Figure 1 View of plantar tissues with shore hardness values (peak plantar pressures exceeding 200kPa indicated by ‘*’) – Subject 1.

Location Hardness (Shore O) of skin – Right foot [kPa  with 3mm poron]
1st MPJ 191 [191.26]
3rd MPJ 80 [80.19]
Heel 236* [235.73]

Table 1 Plantar tissue hardness and peak plantar pressures – subject 1.

Case 2

Subject 1 is a 70-year old male with type 2 diabetes and a right amputation through the first metatarsal. There is a history of ulceration at the right 2nd MPJ and distal aspect of the left 3rd toe and the right 2nd MPJ ulcer has been open within the prior 3 months . The plantar tissues appeared thin and dry, with reduced padding under the MPJs. Callus was visible particularly at the right 2nd MPJ and left 1st and 2nd MPJ. Plantar tissue hardness was tested at the heel, all MPJs and the cut end of the right 1st metatarsal (Figure 2) and ranged between 20 – 70 shore O. PPP were measured at MPJs 1 (cut end of metatarsal on right), 2 and 5 in addition to the heel. The right 2nd MPJ and left MPJs 1-2 exceeded 200kPa (Table 2).

Figure 2 View of plantar tissues with shore hardness values (peak plantar pressures exceeding 200kPa indicated by ‘*’) – Subject 2.

Location Hardness (Shore O) of skin – Right foot (1st ray amputation) Hardness (Shore O) of skin – Left foot
1st MPJ 20 (cut end of 1st metatarsal)  [118.52] 50* [423.34]
2nd MPJ 70* [563.99] 40* [254.62]
3rd MPJ 45 35
4th MPJ 55 40
5th MPJ 45 [78.74] 45 [74.46]
Heel 30 [108.11] 30 [123.35]

Table 2 Plantar tissue hardness and peak plantar pressures – Subject 2 (*location which exceeds 200kPa when walking on 3mm grey poron. Note sites tested for pressure = 1st MPJ, 2nd MPJ, 5th MPJ, heel).

Case 3

Subject 3 is a 70-year old male with type 2 diabetes. He has an amputation through the right first metatarsal in addition to removal of the right second toe. There is a history of ulceration at the left 1st MPJ and distal aspect of the right 4th toe but the feet have been ulcer free for over 12 months. The plantar tissues appeared generally good, with reasonable padding under most of the MPJs, but callus present at the left 1st MPJ and distal aspect of the right 4th toe. Plantar tissue hardness was tested at the heel, all MPJs, the cut end of the right 1st metatarsal and medial/lateral aspects of the plantar midfoot (Figure 3) and ranged between 28 – 60 shore O. PPPs were measured at MPJs 1 (cut end of metatarsal on right), 2 and 5 in addition to the heel. The right cut end of 1st metatarsal and left 1st MPJs exceeded 200kPa (Table 3).

Figure 3 View of plantar tissues with shore hardness values (peak plantar pressures exceeding 200kPa indicated by ‘*’) – Subject 3.

Location Hardness (Shore O) of skin – Right foot (1st ray amputation) [peak plantar pressure on 3mm poron / custom foot orthosis – kPa] Hardness (Shore O) of skin – Left foot [peak plantar pressure on 3mm poron / custom foot orthosis – kPa]
1st MPJ 55 (cut end of 1st metatarsal)* [234/177] 60* [330/306]
2nd MPJ 45 [157/55] 45 [25/132]
3rd MPJ 40 30
4th MPJ 50 40
5th MPJ 40 [113/39] 55 [18/26]
Medial arch 59 36
Lateral arch 40 41
Heel 30 [138/165] 28* [221/136]

Table 3 Plantar tissue hardness and peak plantar pressures – Subject 3 (*location which exceeds 200kPa when walking on 3mm grey poron. Note sites tested for pressure= 1st MPJ, 2nd MPJ, 5th MPJ, heel).

Case 4

Subject 4 is a 60-year old female with type 2 diabetes. She has a right trans-tibial amputation and a history of Charcot foot on the left in addition to removal of the left 5th toe. There is a history of ulceration, most recently at the dorsal hallux but the feet have been ulcer free for over 12 months. The plantar tissues appear in generally good condition, with reduced padding under the MPJs, and a very prominent lateral plantar midfoot. Plantar tissue hardness was tested at the heel, MPJs 1,3 and 5, medial arch, lateral plantar Charcot midfoot prominence and the skin adjacent to the midfoot prominence (Figure 4) and ranged between 30-70 Shore O. PPPs were only measured at the lateral plantar Charcot midfoot prominence, and exceeded 200kPa (Table 4).

Figure 4 View of plantar tissues with shore hardness values – Subject 4.

Location Hardness (Shore O) of skin
1st MPJ 30
2nd MPJ 32
3rd MPJ 32
4th MPJ 33
5th MPJ 70
Medial arch 32
Lateral midfoot Charcot prominence under cuboid region 70* [509kPa]
Tissue adjacent to Charcot prominence 40
Heel 45

Table 4 Plantar tissue hardness and peak plantar pressures – Subject 4. (*location which exceeds 200kPa when walking on 3mm grey poron. Note site tested for pressure = Lateral midfoot Charcot prominence under cuboid region).

Case 5

Subject 5 is a 75-year old male with type 2 diabetes. He has a history of Charcot foot on the right side, causing medial collapse around the talonavicular joint. There is a history of ulceration, and at the most recent assessment there were active ulcers at the right medial navicular/cuneiform region and right 5th toe.  The plantar tissues appear dry, with reduced padding under the MPJs, and callus under the 1st and 2nd MPJs bilaterally (Figure 5). Plantar tissue hardness was tested at the heel, MPJs 1,2 and 3, and ranged between 40-78 Shore O. PPPs were measured at the heel, MPJs 1,2 and 3, and exceeded 200kPa at the 1st and 2nd MPJs bilaterally (Table 5).

Figure 5 View of plantar tissues with shore hardness values (peak plantar pressures exceeding 200kPa indicated by ‘*’) – Subject 5.

Location Hardness (Shore O) of skin – Right (Charcot side) [peak plantar pressure on 3mm poron / custom foot orthosis – kPa] Hardness (Shore O) of skin – Left [peak plantar pressure on 3mm poron / custom foot orthosis – kPa]
1st MPJ 60* [307 / 91] 73* [291 / 94]
2nd MPJ 78* [257 / 65] 50* [360 / 136]
3rd MPJ 40 [32 / 27] 42 [152 / 71]
Heel 45 [61 / 26] 45 [169 / 111]

Table 5 Plantar tissue hardness and peak plantar pressures – Subject 5 (*location which exceeds 200kPa when walking on 3mm grey poron).

Discussion

A wide range of tissue hardness values were recorded, ranging between 20-78 Shore O. PPP also varied widely, between 18-564kPa. Considering the plantar heel, a smaller range of hardness values was recorded, between 28-45 Shore O. This is similar to the 35-50 (Shore A) reported in a diabetic group by another author [8]. Two heels exceeded 200kPa when tested – their hardness values were 28 and 41 Shore O (mean 35). The remaining heels with both durometer and pressure data (n=5) had a mean hardness of 36 Shore O. This, combined with the fact that the two hardest heels (45 Shore O) did not exceed the pressure threshold, does not seem to show an obvious prediction of high pressures by testing tissue hardness at the heel. The forefoot included higher hardness values, ranging between 28-78 Shore O. This is a wider range than the 45-50 Shore A reported by Martinez Santos [8]. Eight MPJs tested exceeded 200kPa; the average tissue hardness of these sites was 60 Shore O. In comparison, the remaining MPJs with both durometer and pressure data (n=18) had a mean tissue hardness of 42 Shore O. Forefoot hardness values of 60 Shore O or higher always predicted PPPs exceeding 200kPa. However of 11 sites exceeding 200kPA, five (45%) had tissue hardness values below 60 Shore O. Forefoot hardness values below 40 were never associated with PPP exceeding 200kPa. While these observations seem to show some relationship between forefoot tissue hardness and dynamic PPP, which has been observed elsewhere ⁠, it would appear that other factors also influence PPP [10]. The data may suggest cut-off values, with all tissue hardness <40 predicting safe PPPs and all tissue hardness 60+ predicting dangerous PPP. This could suggest that durometer testing of forefoot tissues offers an alternative to instrumented pressure measurement, in contexts where this technology is unavailable. However further research would be required to clarify these initial findings.

Conclusion

Use of a durometer was found to be feasible within a clinical setting, and some initial data for comparison is provided. Hardness testing offers quantification of more subjective assessment methods such as palpation. While plantar tissue hardness alone is unlikely to be a singular value which can guide treatment, it may offer a helpful addition to existing clinical assessments.

Acknowledgements

This work was completed while affiliated with the above organisations, however, at the time of publication the author is affiliated with: John Florence Limited, Paediatric Orthotic Centre, Foundry Lane, Lewes, East Sussex, BN7 2AS, UK

References

  1. Vileikyte L. Diabetic foot ulcers: a quality of life issue. Diabetes Metab Res Rev. 2001 Jul 1;17(4):246–9.
  2. Boyko EJ, Ahroni JH, Stensel V, Forsberg RC, Davignon DR, Smith DG. A prospective study of risk factors for diabetic foot ulcer. The Seattle Diabetic Foot Study. Diabetes Care. 1999 Jul 1;22(7):1036–42.
  3. Pham H, Armstrong DG, Harvey C, Harkless LB, Giurini JM, Veves A. Screening techniques to identify people at high risk for diabetic foot ulceration: a prospective multicenter trial. Diabetes Care. 2000 May 1;23(5):606–11.
  4. Thomas VJ, Patil KM, Radhakrishnan S, Narayanamurthy VB, Parivalavan R. The role of skin hardness, thickness, and sensory loss on standing foot power in the development of plantar ulcers in patients with diabetes mellitus–a preliminary study. Int J Low Extrem Wounds. 2003;2(3):132-9.
  5. Chao CYL, Zheng Y-P, Cheing GLY. Epidermal Thickness and Biomechanical Properties of Plantar Tissues in Diabetic Foot. Ultrasound Med Biol. 2011 Jul 1;37(7):1029–38.
  6. Klaesner JW, Hastings MK, Zou D, Lewis C, Mueller MJ. Plantar tissue stiffness in patients with diabetes mellitus and peripheral neuropathy. Arch Phys Med Rehabil. 2002 Dec 1;83(12):1796–801.
  7. Piaggesi A, Romanelli M, Schipani E, et al. Hardness of Plantar Skin in Diabetic Neuropathic Feet. J Diabetes Complications. 1999 May 1;13(3):129–34.
  8. Martínez Santos A. An investigation into the effect of customised insoles on plantar pressures in people with diabetes [thesis]. University of Salford; 2016. Available from: http://usir.salford.ac.uk/41408/1/Ana Martinez Santos Thesis.pdf
  9. Bus SA, Ulbrecht JS, Cavanagh PR. Pressure relief and load redistribution by custom-made insoles in diabetic patients with neuropathy and foot deformity. Clin Biomech. 2004 Jul 1;19(6):629–38.
  10. Menz HB, Zammit G V., Munteanu SE. Plantar pressures are higher under callused regions of the foot in older people. Clin Exp Dermatol. 2007 Jul 1;32(4):375–80.

Issue 11(4), 2018

 


Case study of rare incidence of gas gangrene caused by Raoultella Ornithinolytica
by Edward Mirigliano DPM, MBA, Kyle Hopkins DPM, Samantha Banga, DPM


Staged treatment of plantar midfoot ulceration with use of a Hemisoleus Muscle Flap, application of external fixation and split-thickness skin graft
by Stephanie Oexeman, DPM; Mallory J. Schweitzer, DPM, MHA; Craig E. Clifford DPM, MHA, FACFAS, FACFAOM


Open tongue-type calcaneal fracture treated with the external fixation bent wire technique
by Dalton Ryba DPM, Jordan James Ernst DPM MS, Kyle Duncan DPM, Alan Garrett DPM FACFAS


Open tongue-type calcaneal fracture treated with the external fixation bent wire technique

by Dalton Ryba DPM1*, Jordan James Ernst DPM MS2, Kyle Duncan DPM3, Alan Garrett DPM FACFAS4

The Foot and Ankle Online Journal 11 (4): 3

Traditionally, tongue-type calcaneal fractures have been treated using internal fixation. External fixation has been described to a lesser degree in the treatment of these injuries, though not in the setting of an open fracture. We present a case of an open tongue-type calcaneal fracture treated with external fixation, utilizing a tensioned wire affixed to the frame that imparts compression across the fracture site. With this method, maximal respect to the soft tissues is rendered, and soft tissue insult is minimized. This patient achieved timely soft tissue coalescence and fracture union, with a return to pre-injury activities. To our knowledge, this technique has not been previously described in the treatment of an open calcaneal fracture of the posterior tuberosity.

Keywords: Achilles tendon, avulsion fracture, circular frame, Gustilo-Anderson, Ilizarov technique

ISSN 1941-6806
doi: 10.3827/faoj.2018.1104.0003

1 – Chief Foot and Ankle Surgery Resident, Dept. of Orthopedics, John Peter Smith Hospital, Fort Worth, Tx
2 – Fellow, Foot and Ankle Deformity Correction, The Paley Institute, West Palm Beach, Fl
3 – Attending, North Texas Foot and Ankle, Las Colinas, Tx
4 – Attending, Foot and Ankle Surgery, Dept. of Orthopedics, John Peter Smith Hospital, Fort Worth, Tx
* – Corresponding author: dalton.m.ryba@gmail.com


A fracture of the calcaneus, despite being the most common fracture regarding the tarsal bones, occurs only 11.5 instances in 100,000, according to a 10 year epidemiological study [1]. Open calcaneal fractures are diagnosed in merely 5-13 percent of these injuries collectively [2-5]. The surgical indications for calcaneal fractures are controversial. Soft tissue complications are abundantly reported in the literature concerning open reduction internal fixation of closed calcaneal fractures [6-9]. In fact, there is literature advocating non-operative treatment of displaced intra-articular fractures to attempt prevent these soft tissue complications [10]. However, an open calcaneal fracture is considered a surgical emergency. This situation presents a unique surgical obstacle regarding initial stabilization and definitive fixation. A variety of techniques have been described in the initial and subsequent management of open fractures in general [11-16]. The literature, however, is scant with recommendations addressing minimally invasive soft tissue friendly surgical options for open calcaneal fractures.

The primary goals of open fracture management include prevention of infection and soft tissue compromise, which can be achieved through aggressive surgical irrigation and debridement, parenteral antibiotics, anatomic reduction of the fracture and stabilization of the osseous fragments.

Osseous union and restoration of function are also sought, as with treatment of any orthopedic injury [17]. This often requires a staged surgical approach with initial debridement and often external fixation for stabilization, followed by internal fixation once soft tissues have coalesced [18]. This protocol, although arguably the gold standard in open fracture management, is not without drawbacks. These includes increased hospital and patient costs, length of hospital stay and associated risks such as deep vein thrombosis, as well as risks of anesthesia [19-23].  The primary aim of this case report is to present a single stage technique for the treatment of open tongue-type calcaneal fractures. In this report, one patient with an open calcaneal fracture underwent irrigation and debridement with application of external fixation and fracture fixation through bent wire technique, achieving a favorable outcome. Despite some literary evidence supporting multi-staged surgical management of open calcaneal fractures, this report provides a single stage technique that has shown promise regarding reduction of soft tissue complications and return to function, while reducing the aforementioned multi-stage surgical pitfalls.

Methods

A single patient received external ring fixation with bent wire technique after presenting to the emergency department with an open tongue-type calcaneal fracture. This was a work related injury resulting from a steel beam impact and laceration through a work boot. Clinically the patient presented with a medial heel deficit measuring 1.0 cm x 6.0 cm down to the level of bone, with minimal gross debris present (Figure 1). An adjacent full thickness deficit was noted to the plantar heel, not extending to bone (Figure 1). Tenting of the posterior heel was evident. The patient was deemed neurovascularly intact on examination. Standard radiographs diagnosed an isolated tongue-type calcaneal fracture (Figure 2), with evidence of intra-articular involvement of the posterior facet visualized on CT scan (Figure 3). The patient received TDaP tetanus vaccine and Ancef upon arrival to the emergency department.

Figure 1 Clinical photograph of the patient upon presentation to the emergency department. The large medial defect extends to bone. The smaller, more posterior defect, did not extend to bone. There was no evidence of gross contamination.

Figure 2 Lateral radiograph demonstrating the tongue-type calcaneal fracture with significant displacement.

Initial bedside irrigation and debridement was performed, however closed reduction of the posterior tuber avulsion was unsuccessful. Verbal and written consent was obtained to then proceed with surgical intervention.

Figure 3 A CT scan clearly demonstrates the intra-articular nature of the fracture. Soft tissue emphysema is clearly evident.

Figure 4 Intraoperative fluoroscopy demonstrates anatomic reduction of both fracture lines

Figure 5 Closure of the medial heel defects using subcuticular Monocryl.

Operative Technique

The patient received IV antibiotics preoperatively and under mild sedation was brought into the operating room. He was placed supine on the operating table. A formal surgical “time-out” was performed in which the patient, procedure and site were identified. The patient underwent general anesthesia without complication and the operative limb was scrubbed, prepped and draped in usual aseptic manner. A tourniquet was not raised so as to appropriately control hemostasis intra-operatively. The soft tissue defect was irrigated with 9 liters of sterile saline and closed primarily utilizing subcuticular Monocryl® (poliglecaprone, Ethicon, Inc., a division of Johnson & Johnson, Somerville, NJ). After application of a standard pre-built multi-plane Ilizarov external fixator to the operative extremity, two k-wires were placed in bicortical fashion through the superior fragment of the calcaneus and a single k-wire was placed through the inferior fragment, also bicortically. Manually, the superior wires were then bent down to the frame inferiorly, imparting compression across the fracture site. Tensiometers were then used to tension the wires to the foot plate at 75N. After tensioning, intraoperative fluoroscopy was utilized to confirm anatomic reduction and fracture compression (Figure 4). A secondary fracture of the plantar aspect was also noted on fluoroscopic imaging and fixated using two 2.0mm Steinmann Pins. The incision site was closed with subcuticular Monocryl (Figure 5). An incisional negative pressure wound vac was applied to the site of open fracture and the operative extremity was placed in a compressive dressing. The external fixator was then dressed in a sterile surgical dressing. Immediate post-operative radiographs are presented in Figure 6.

The patient was admitted for IV antibiotics based on our facility’s open fracture protocol.  The incisional vac was removed prior to discharge at post-op day 2. The laceration was reinforced with simple suture after debridement of mild skin edge necrosis at the apex.

Figure 6 Postoperative lateral radiograph demonstrating anatomic fracture reduction.

Figure 7 Clinical image at 2 weeks postoperatively after suture removal. The Steinmann pin was removed as well due to loosening.

Figure 8 Clinical image at 5 weeks showing the superficial nature of the wound.

Figure 9 Trabeculation is seen across the fracture lines on lateral and lateral oblique radiographs at 5 weeks post-operatively.

Results

The patient was evaluated in clinic at one week and two weeks postoperatively for soft tissue scrutiny. In the interim, the patient had been undergoing twice weekly dressing changes via home health with packing changes to area of apical necrosis and silver dressings along the coapted skin edges.

Figure 10 Lateral radiograph at 10 weeks postoperatively with union noted at the primary fracture line.

Figure 11 Union of both fracture lines is appreciated at 4 months post-operatively.

Sutures were removed at two weeks as well as the Steinman pin due to loosening (Figure 7). The apical wound was addressed in clinic with serial packing and ultimately porcine trilayer grafting. At 5 weeks, the wound was superficial (Figure 8 a,b). Trabeculation could be appreciated radiographically at this time via standard radiograph (Figure 9). Osseous union was visualized at eight weeks postoperatively. The patient underwent external fixator removal (Figure 10) and amniotic graft application at 9 weeks postoperatively for stagnant healing of the apical wound.

Figure 12 Clinical image of the patient 10 months post-operatively.

The patient was then transitioned to full weight bearing over the next four weeks with progression through a controlled ankle motion boot. Radiographs at 4 months display union of both fracture lines (Figure 11). At the most recent appointment, 10 months post-operative, patient has returned to work without restrictions. Currently, the patient’s only complaint is intermittent pain and tenderness to touch along the medial heel. According to the patient, the frequency of these sensations has slowly decreased over time. It is unclear at this time to what extent his neuritic symptoms will resolve. His medial heel has remained ulceration free and is in neutral position in resting calcaneal stance position (Figure 12 a,b). It was noted that the patient had a slight increase in heel width, however the patient was able to return to tennis shoes and work boots that he was wearing pre-injury without complaints.

Discussion

In their seminal work Takahashi, Mitsuaki, and Saegusa described a technique treating a similar calcaneal fracture presentation. Although their case report describes a closed injury, the principles of careful soft tissue management remain the same through the application of external fixation. While their efforts attempt to prevent an impending open fracture, the so called “open fracture in evolution”, we present an attempt to prevent further insult to an already compromised soft tissue envelope. In closed injuries, the “Hurricane Strap” form of internal fixation that we have previously described has been our preferred fixation modality for tongue-type calcaneal fractures. Ilizarov fixation was first described for this fracture pattern by Ramanujam et al., however, the reduction was maintained by placing the ankle in plantarflexion by way of the fixator and thus reducing the deforming force of the Achilles tendon. In their technique, Steinmann pins are placed across the fracture site but not affixed to the frame. Yet, prolonged immobilization of the ankle joint in a high degree of plantarflexion could result in contracture that would make weight bearing after fixator removal difficult. Takahashi et al. were the first to describe reduction by way of tensioned wires. To our knowledge, we are the first to describe this technique in the scenario of an open fracture. Fixation of the interfragmentary wires to the fixator itself in a tensioned fashion has the advantage of imparting active compression across the fracture site rather than simply holding the fragment in place and relying on a static joint position. Conceivably, the resistance to failure would be greater biomechanically superior to a non-tensioned interfragmentary pin or wire that cannot effect compression. A saw bone model allows for a true appreciation of the technique (Figure 13 a,b). A schematic is provided to further illustrate this method (Figure 13c).

We concede that this technique would be of limited use with smaller osteoporotic fragments. In contrast however, we do not suggest fixation of these fragments.

Figure 13 Bent wire construct (A) a sawbone model allows for easy visualization of the construct with the tensioned wire passing through the displaced fracture fragment. The wire is tensioned and the concave side of the arc faces in the desired direction of compression. (B) Compression across the fracture fragment from a lateral perspective. (C) A schematic of the technique superimposed on a lateral radiograph (Figure 13a and Figure 13b Reproduced from: A new treatment for avulsion fracture of the calcaneus using an Ilizarov external fixator, Injury, 44(11), Takahashi M, Noda M, Saegusa Y., 1640-3.Copyright (2013), with permission from Elsevier).

We distinguish a true tongue-type fracture, as treated in this article, from the smaller Achilles avulsion fractures described by Beavis and Rowe, and the “Iowa” fracture described by Kathol [6,7,8]. Tongue-type fractures are akin to the cleavage or “wedge” type fractures detailed by Hedlund, or the Essex-Lopresti described tongue-type fracture without frank joint collapse [9,10]. Given their size and extra-articular nature, smaller avulsion fractures can often be excised without biomechanical consequence. The Achilles can then be re-anchored to the remaining calcaneus as described by Greenhagen [11]. This is especially useful in the osteoporotic host where screw fixation is especially apt to fail, in whom these avulsion-type fractures are more common. The fracture described by Ramanujam would in fact be one such fracture pattern were we would recommend excision given its small size. Patients incurring tongue-type fractures tend to be somewhat younger than those sustaining avulsion fractures, which are largely insufficiency fractures in osteoporotic patients. In the event of a true tongue-type fracture, fixation is mandatory given their predisposition for soft tissue compromise and often concomitant articular involvement.

With respect to open fractures involving the posterior calcaneal tuber, internal fixation has been the method of choice for many authors. In this scenario, retained internal fixation could of course serve as a nidus for infection and require removal, necessitating substantial incisions and thus further soft tissue trauma. Additionally, depending on the location and size of the soft tissue deficit, their initial placement could demand further dissection into the already tenuous soft tissue environment.

Delays in the treatment of these injuries can undoubtedly lead to the need for rapid ascension of the soft tissue coverage ladder, even requiring free tissue transfer [21]. These delays can be especially common in the neuropathic host. In the scenario of free tissue transfer, our technique would provide both protection of the flap as well as minimal insult to the transferred tissue. The precarious position of the posterior lower extremity in the non weight bearing patient can make offloading of this area difficult without external fixation.

In conclusion, the bent wire technique has shown to be a valuable tool in our treatment of an open tongue-type calcaneal fracture and is our standard approach to treating these injuries. With minimal surgical insult to the soft tissues, wound healing concerns can be mitigated to the greatest extent possible. In the future, studies of larger sample sizes, biomechanical testing, and even direct comparison of this presented method to other fixation techniques would be useful.

References

  1. Mitchell MJ, Mckinley JC, Robinson CM. The epidemiology of calcaneal fractures. Foot (Edinb). 2009;19(4):197-200.
  2. Weber M, Lehmann O, Sagesser D, Krause F. Limited open reduction and internal fixation of displaced intra-articular fractures of the calcaneum. J Bone Joint Surg Br. 2008;90:1608–1616.
  3. Harvey EJ, Grujic L, Early JS, Benirschke SK, Sangeorzan BJ. Morbidity associated with ORIF of intra-articular calcaneus fractures using a lateral approach. Foot Ankle Int. 2001;22(11):868-73.
  4. Zhang X, Liu Y, Peng A, Wang H, Zhang Y. Clinical efficacy and prognosis factors of open calcaneal fracture: a retrospective study. Int J Clin Exp Med. 2015;8(3):3841-7.
  5. Siebert CH, Hansen M, Wolter D. Follow-up evaluation of open intra-articular fractures of the calcaneus. Arch Orthop Trauma Surg. 1998;117(8):442-7.
  6. Al-mudhaffar M, Prasad CV, Mofidi A. Wound complications following operative fixation of calcaneal fractures. Injury. 2000;31(6):461-4.
  7. Bergin PF, Psaradellis T, Krosin MT, et al. Inpatient soft tissue protocol and wound complications in calcaneus fractures. Foot Ankle Int. 2012;33(6):492-7.
  8. Abidi NA, Dhawan S, Gruen GS, Vogt MT, Conti SF. Wound-healing risk factors after open reduction and internal fixation of calcaneal fractures. Foot Ankle Int. 1998;19(12):856-61.
  9. Koski A, Kuokkanen H, Tukiainen E. Postoperative wound complications after internal fixation of closed calcaneal fractures: a retrospective analysis of 126 consecutive patients with 148 fractures. Scand J Surg. 2005;94(3):243-5.
  10. Griffin D, Parsons N, Shaw E, et al. Operative versus non-operative treatment for closed, displaced, intra-articular fractures of the calcaneus: randomised controlled trial. BMJ. 2014;349:g4483.
  11. Bhandari M, Guyatt GH, Swiontkowski MF, Schemitsch EH. Treatment of open fractures of the shaft of the tibia. J Bone Joint Surg Br. 2001;83(1):62-8.
  12. Gustilo, R.B., Merkow, R.L. and Templeman, D.A.V.I.D., 1990. The management of open fractures. JBJS, 72(2), pp.299-304.
  13. Byrd, H.S. and Spicer, T.E., 1985. Management of open tibial fractures. Plastic and reconstructive surgery, 76(5), pp.719-730.
  14. Chapman, M.W. and Mahoney, M., 1979. The role of early internal fixation in the management of open fractures. Clinical orthopaedics and related research, (138), pp.120-131.
  15. Sirkin, M., Sanders, R., DiPasquale, T. and Herscovici, J.D., 2004. A staged protocol for soft tissue management in the treatment of complex pilon fractures. Journal of orthopaedic trauma, 18(8 Suppl), pp.S32-8.
  16. Aldridge JM, Easley M, Nunley JA. Open calcaneal fractures: results of operative treatment. J Orthop Trauma. 2004;18(1):7-11.
  17. Cross WW, Swiontkowski MF. Treatment principles in the management of open fractures. Indian J Orthop. 2008;42(4):377-86.
  18. Diwan A, Eberlin KR, Smith RM. The principles and practice of open fracture care, 2018. Chin J Traumatol. 2018.
  19. Passias PG, Ma Y, Chiu YL, Mazumdar M, Girardi FP, Memtsoudis SG. Comparative safety of simultaneous and staged anterior and posterior spinal surgery. Spine. 2012;37(3):247-55.
  20. Collins TC, Daley J, Henderson WH, Khuri SF. Risk factors for prolonged length of stay after major elective surgery. Ann Surg. 1999;230(2):251-9.
  21. Tess BH, Glenister HM, Rodrigues LC, Wagner MB. Incidence of hospital-acquired infection and length of hospital stay. Eur J Clin Microbiol Infect Dis. 1993;12(2):81-6.
  22. Härkänen M, Kervinen M, Ahonen J, Voutilainen A, et al. Patient-specific risk factors of adverse drug events in adult inpatients – evidence detected using the Global Trigger Tool method. J Clin Nurs. 2015;24(3-4):582-91.
  23. Caminiti C, Meschi T, Braglia L, et al. Reducing unnecessary hospital days to improve quality of care through physician accountability: a cluster randomised trial. BMC Health Serv Res. 2013;13:14.
  24. Beavis RC, Rourke K, Court-brown C. Avulsion fracture of the calcaneal tuberosity: a case report and literature review. Foot Ankle Int 29:863-866, 2008.
  25. Rowe CR, Sakellarides HT, Freeman PA, et al. Fractures of os calcis. A long term follow-up study of one hundred forty-six patients. JAMA 184:920-923, 1963.
  26. Kathol MH, El-khoury GY, Moore TE, Marsh JL. Calcaneal insufficiency avulsion fractures in patients with diabetes mellitus. Radiology. 180:725-729, 1991.
  27. Hedlund LJ, Maki DD, Griffiths HJ. Calcaneal fractures in diabetic patients. J Diabetes Complicat 12:81-7, 1998.
  28. Essex-lopresti P. The mechanism, reduction technique, and results in fractures of the os calcis. Br J Surg 39:395-419, 1952.
  29. Greenhagen RM, Highlander PD, Burns PR. Double row anchor fixation: a novel technique for a diabetic calcaneal insufficiency avulsion fracture. J Foot Ankle Surg 51:123-127, 2012.

Staged treatment of plantar midfoot ulceration with use of a Hemisoleus Muscle Flap, application of external fixation and split-thickness skin graft

by Stephanie Oexeman, DPM1*; Mallory J. Schweitzer, DPM, MHA2; Craig E. Clifford  DPM, MHA, FACFAS, FACFAOM3

The Foot and Ankle Online Journal 11 (4): 2

Muscle flaps are a versatile option for limb salvage that can provide coverage for chronic ankle and foot defects that fail to heal from other conservative and surgical treatments. We discuss the use of a medial hemisoleus muscle flap for treatment of a chronic foot ulcer following dehiscence of an intrinsic pedicled muscle flap. Hemisoleus muscle flaps are utilized for soft tissue defects of the distal third of the lower extremity but are not commonly utilized for coverage of defects on the plantar foot.

Keywords: wound care, muscle flap, lower extremity, hemisoleus muscle flap, medial hemisoleus muscle flap

ISSN 1941-6806
doi: 10.3827/faoj.2018.1104.0002

1 – Resident Physician, PGY-1, Franciscan Foot & Ankle Institute, Federal Way, WA,
2 – Resident Physician, PGY-2, Franciscan Foot & Ankle Institute, Federal Way, WA,
3 – Residency Director, Franciscan Foot & Ankle Institute, Federal Way, WA
* – Corresponding author: s.oexeman@gmail.com


We discuss the use of a medial hemisoleus (MHS) flap for treatment of a chronic foot ulcer following dehiscence of an intrinsic pedicled muscle flap. This case study presents our treatment of a chronic wound that failed to heal despite local wound care and several attempts at primary closure. We present our surgical technique for mobilizing the MHS flap and recommend concomitant use of external fixation to decrease motion of the flap on the wound bed, allowing for neovascularization and full incorporation.

Case Study

A case is presented of a fifty-seven-year-old male who underwent a plantar fasciotomy with a subsequent postoperative soft tissue infection. This resulted in a chronic, painful wound to the plantar medial left foot after the infection resolved. Non-invasive vascular studies and clinical vascular examination were normal. He failed conservative therapy including local wound care and offloading and elected to undergo primary closure eight months after the plantar fasciotomy. A fissure developed along the incision six weeks postoperatively and persisted for nine months despite continued wound care. A second attempt at primary closure was made and approximately three weeks later the incision partially dehisced. Progressive healing was achieved for three months, but the patient fell at this time which resulted in the wound reopening. An MRI was obtained and ruled out osteomyelitis or presence of a foreign body. The patient then elected to undergo scar excision with the placement of an abductor hallucis muscle flap. The patient had an uneventful postoperative course and was transitioned to heel weight bearing at twelve weeks postoperatively. At four months postoperatively, the incision partially dehisced and became a chronic ulcer (Figure 1).

Figure 1 Preoperative (A) Chronic ulceration to plantar medial left foot (B) Ellipsoid excision of the ulcer.

At this time, the patient was given the option of a  below-knee amputation and he declined. After five months of additional conservative therapy with no improvement  in appearance of the wound, another attempt at closure was made by performing a medial hemisoleus flap. The decision was made to utilize an  external fixator to minimize motion of the flap within the wound bed. Three weeks later a split-thickness skin graft (STSG) was applied and the external fixator was removed at this time. The incisions healed and the graft and flap had completely incorporated at ten weeks postoperatively (Figure 4). The patient is ambulatory in accommodative shoe gear and has not had a recurrence of the soft tissue defect after twenty-three months of follow-up.

Surgical Technique

The patient was brought to the operating room and placed on the operating room table in the supine position. A tourniquet was not utilized during the procedure. An elliptical incision was made to encompass the wound (Figure 1). Due to previous surgeries, a significant amount of scar tissue was encountered that extended to the level of the plantar musculature. Attention was directed to the tarsal tunnel and dissection was carried through the flexor retinaculum. The wound was irrigated with copious amounts of normal saline and all nonviable soft tissue was excised; leaving a large soft tissue defect (Figure 2).

Figure 2 Intraoperative (A) Excision of Chronic Wound (B) Incision and dissection of medial soleus (C) Closure with application of External Fixation for ankle motion and flap protection.

The decision was made to transpose a medial hemisoleus muscle flap for coverage of the defect. Continuing the incision from the tarsal tunnel, a longitudinal incision was made over the medial aspect of the calf. The incision was carried down to the crural fascia. The fascia was incised longitudinally allowing exposure to the gastroc-soleus muscle complex. The soleus muscle belly was identified and the medial portion of the muscle was transected proximally and freed from lateral muscle belly along the central raphe down to the level of the tarsal tunnel.  An intraoperative doppler was utilized during this dissection to identify perforators of the muscle. With sharp dissection, the epimysium was excised. The muscle was transposed through the tarsal tunnel and placed within the plantar soft tissue defect. 3-0 nylon was used to secure the flap in the proper position, with no tension on the flap. The medial incision was closed in layers and the skin was closed with staples. Vessel loops in a zig-zag pattern were used to reduce tension to the edges of the incision.

Figure 3 Intraoperative (A) status post 3 weeks from muscle flap (B) Fenestrated STSG applied to debrided muscle flap.

An external fixator consisting of a tibial block with two full rings and a distal block with a full ring was used to encompass the forefoot. Opposing olive wires were inserted using standard techniques.

Three weeks following the frame application, the patient was brought back to the operating room for debridement of the muscle flap and application of a split-thickness skin graft (STSG). The external fixator was removed and extremity was prepped and draped in a sterile manner. The muscle flap was debrided of eschar tissue, leaving a mixture of bleeding granular and muscular tissue (Figure 3). The muscle flap measured 3cm x 9cm. The site was covered with an intermediate STSG harvested from the proximal left thigh with use of a dermatome. The skin graft was meshed and sutured in place using 3-0 Monocryl. The skin graft was covered with a sterile dressing and a wound VAC was applied. The STSG was fully incorporated after 10 weeks of local wound care (Figure 4).

Discussion

MHS flap reliability has been questioned due to variability in vascularity, but successful coverage of distal lower extremity defects have been reported. Our use of a MHS flap for plantar foot defects is a novel application.

The performing surgeon should have an in-depth knowledge not only of the muscular but also of the vascular anatomy. There are many classifications within the literature discussing mapping the vasculature of the lower leg.

Figure 4 Clinical images (A) healing STSG five weeks postoperatively and (B)  fully incorporated split thickness skin 10 weeks graft.

Angiosomes should always be acknowledged throughout the surgical planning and intervention. Angiosomes are a unit consisting of the skin, subcutaneous tissue, fascia, muscle, and bone being supplied by a source artery. The human body has forty angiosomes, with six being located in the foot and four located within the lower leg [1,2]. Mathes and Nahai’s classification divides muscle flaps accordingly to their blood supply. The soleal muscle flap is a type II flap, meaning it has one major pedicle and several minor pedicles [2,3]. Its dominant  pedicle is the posterior tibial artery and the perforating branches of this artery are the secondary pedicles [2,4-7].  The vascular supply of the medial soleus muscle body is mainly from the posterior tibial artery (PTA) via multiple minor pedicles [4,5,8]. The medial soleus has perforators from the PTA extending the length of the muscle [9,10].  

Ward, et al. state that perforators can be found on the posterior border of the tibia roughly 5 cm, 10 cm, and 15 cm proximal to the ankle joint [11].  Similarly, Raveendran, et al. report the distal perforating arteries of the PTA averaged 6.5 cm, 11.6 cm, and 16.8 cm from the medial malleolus [12].

When planning for coverage, the entire soleal muscle can cover defects approximately 26 cm2 [2]. However, the MHS has an extended arc of rotation compared to a full soleal flap which allows a greater percentage of coverage [6,7,13,14]. The medial soleus belly averages 25.4 cm in length, 6.9 cm in width, and has a mean surface area of 87.5 cm2 [15]. Techniques, such as excising the epimysium, can also increase the flap’s range by 20% [4].

Prior to incision, perforators should be marked appropriately along the posterior border of the tibia [9,11]. For the surgical approach, we prefer a medial incision overlying the posterior compartment. Preserving the saphenous neurovascular bundles can be achieved and blunt dissection can be utilized to separate the gastrocnemius from the soleus [2,11]. It is highly encouraged to use intraoperative doppler examination throughout the surgery to confirm the major pedicle is viable and only minor perforators are being ligated [2]. The medial body of the soleus should be dissected from the lateral portion at the “C-point”, or the perforator located approximately 15 cm from the ankle joint [11].  Bourdais-Sallot et al. reported the pivot point for MHS is 14.5 cm from the top of the medial malleolus or 32.5% of the tibial length [15].  The lateral soleal muscle body is left intact to help maintain plantar-flexion at the ankle [9,2].

Conclusion

To our knowledge, the use of a MHS flap for coverage of a plantar foot soft tissue defect has not been previously described. MHS flaps have been used to cover defects in the proximal and distal lower extremity [7,10]. Techniques can be used to extend the range of coverage of the medial soleus in order to reach the plantar foot.  With careful and proper planning, the MHS flap is an option for coverage of soft tissue defects of the plantar foot.

The goal of our staged procedure was to heal the chronic ulceration and provide a functional lower extremity for ambulation. Within ten weeks of MHS flap with external fixator and STSG, the patient was able to ambulate with a well adhered and fully incorporated graft. No dehiscence has occurred in twenty-three months.

References

  1. Brodmann, Marianne. “The Angiosome Concept in Clinical Practice.” Endovascular Today, May 2013.
  2. Dockery, G. and Crawford, ME. Lower Extremity Soft Tissue & Cutaneous Plastic Surgery. Saunders Elsevier, 2012, pp. 269–288.
  3. Banks, AS, and McGlamry, ED. McGlamry’s Comprehensive Textbook of Foot and Ankle Surgery. Lippincott Williams & Wilkins, 2001, Pp 1513-1519.
  4. Hallock, GG. “Getting the Most from the Soleus Muscle.” Annals of Plastic Surgery, vol. 36, no. 2, 1996, pp. 139–146.
  5. Klebuc, M and Menn, Z. “Muscle Flaps and Their Role in Limb Salvage.” Methodist DeBakey Cardiovascular Journal, vol. 9, no. 2, 2013, pp. 95–98.
  6. Pu, Lee LQ. “Soft-tissue reconstruction of an open tibial wound in the distal third of the leg: a new treatment algorithm”.  Plastic and Reconstructive Surg. 2007;58(1): 78-83. 4.
  7. Pu, Lee LQ. “ Successful soft-tissue coverage of a tibial wound in the distal third of the leg with a medial hemisoleus muscle flap”. Plastic and Reconstructive Surg. 2005;115(1):245-51.
  8. Tobin, CR. “Hemisoleus and Reversed Hemisoleus Flaps.” Plastic and Reconstructive Surgery, vol. 76, no. 1, 1985, pp. 87–96.
  9. Sayed, AT. “Distally Based Medial Hemi-Soleus Muscle Flap Based on the Posterior Tibial Vessels”. AAMJ, Department of Plastic and Reconstructive Surgery, Faculty of Medicine Al-Azhar University; Vol.7,N.1, January 2009.
  10. Schmidt, I. “The Proximally and Distally Pedicled Hemisoleus Muscle Flap as Option for Coverage of Soft Tissue Defects in the Middle Third of Lower Leg.” Trauma and Emergency Care, vol. 2, no. 6, 2017.
  11. Ward, KL, et al. “Cadaveric Atlas for Orthoplastic Lower Limb and Foot Reconstruction of Soft Tissue Defects.” Clinics in Surgery, vol. 3, 28 June 2018.
  12. Raveendran, SS, and Kumaragama, KGJL. “Arterial Supply of the Soleus Muscle: Anatomical Study of Fifty Lower Limbs.” Clinical Anatomy, vol. 16, no. 3, 2003, pp. 248–252.
  13. Pu, Lee LQ. “The Reversed Medial Hemisoleus Muscle Flap and its Role in Reconstruction of an Open Tibial Wound in the Lower Third of the Leg”. Ann Plast Surg 2006 Jan;56(1):59–63.
  14. Pu, Lee LQ. “Further Experience with the Medial Hemisoleus Muscle Flap for Soft-Tissue Coverage of a Tibial Wound in the Distal Third of the Leg.” Plastic and Reconstructive Surgery, vol. 121, no. 6, 2008, pp. 2024–2028.
  15. Bourdais-Sallot, A, et al. “Distally Based Medial Hemisoleus Muscle Flap: Anatomic and Angiographic Study of 18 Lower Limbs”. Annals of Plastic Surgery, vol. 79, no. 1, 2017, pp. 73–78.
  16. Houdek, MT, et al. “Reverse Medial Hemisoleus Flaps for Coverage of Distal Third Leg Wounds.” Journal of Orthopaedic Trauma, vol. 30, no. 4, 2016.

Case study of rare incidence of gas gangrene caused by Raoultella Ornithinolytica

by Edward Mirigliano DPM, MBA1, Kyle Hopkins DPM2, Samantha Banga, DPM3

The Foot and Ankle Online Journal 11 (4): 1

Gas gangrene is a bacterial infection that produces gas in tissues.  It is fast spreading, potentially life-threatening and needs to be addressed promptly.  In this case report, we present a patient that presented with gangrene of his left foot.  He was first seen in the emergency room where blood cultures and x-rays were obtained.  The patient was then promptly treated with OR debridement of the site and the cultures obtained intraoperatively revealed a rare organism, Klebsiella ornithinolytica (currently called Raoultella ornithinolytica).  In addition to the OR debridement, the patient was treated with 6 weeks of IV antibiotics.

Keywords: gas gangrene, osteomyelitis, amputation

ISSN 1941-6806
doi: 10.3827/faoj.2018.1104.0001

1 – Staff Podiatrist, Department of Podiatric Services, Department of Veterans Affairs Medical Center, Lebanon, PA
2 – Chief Podiatric Resident, Department of Podiatric Services, Department of Veterans Affairs Medical Center, Lebanon, PA
3 – Staff Podiatrist, Department of Veterans Affairs Medical Center, Lebanon, PA
* – Corresponding author: EDWARD.MIRIGLIANO2@va.gov


Gas gangrene is a form of tissue necrosis that can be life-threatening. It often occurs at the site of trauma, or recent surgical site, however, can present without an irritating event. Populations at high risk for developing gas gangrene include those with diabetes and atherosclerosis. If suspicion for gangrene is present, it is imperative to obtain tissue and fluid cultures, blood cultures, x-ray, CT scan or MRI of the area. Surgery should be performed quickly to remove dead and infected tissue. Although it is well established that Clostridium spp. causes gas gangrene; non-clostridial involvement is possible. In the present case, x-ray findings indicated gas formation and additionally, Klebsiella ornithinolytica was recovered from surgical specimens. Based on both radiological and microbiological evidence, the diagnosis of Klebsiella Ornithinolytica gas gangrene was established. The patient was treated for 6 weeks with IV antibiotics.

Case Study

A 56-year-old Caucasian male presented to the ER with a 3-day history of foul-smelling discharge from his right foot after having a 5th met resection 2 months ago at a civilian facility. The patient was having constant pain in the foot over the past 2 weeks. Over the last 3 days, he also noticed a redness that was going up the leg along with bluish discoloration of the fourth digit accompanied by edema. There was tenderness of the 4th digit on palpation along with the metatarsal head dorsally despite patients self-described neuropathy of his feet. The patient said that over the last day he had developed fever, chills, and nausea. His medical history was significant for uncontrolled diabetes, hypertension, cocaine abuse, and tobacco abuse.

Figure 1 Demonstrating Gas Gangrene of 4th proximal phalanx.

Figure 2 Post-operative radiographs of Partial 4th ray resection.

Figure 3 Post-operative radiographs of transmetatarsal amputation.

The patient had a 5th ray resection from an outside facility and was unable to give us any other details nor records from that hospitalization.

Inspection at the time of his first visit revealed a 3.5cm x 1.5 cm opening to the fifth metatarsal resection surgical site of the right foot.  There was surrounding erythema to the surgical site and forefoot with lymphangitis streaking accompanied by a purplish discoloration to the fourth digit with pain to palpation.  Also noted were calor and malodor. The dorsum of the foot was erythematous and edematous over the 4th digit and fourth metatarsal. There was a local increase in skin temperature on the dorsal aspect of the left foot compared to that of the contralateral foot. The dorsalis pedis and tibialis posterior pulses were easily palpated and capillary return was within normal limits. His initial temporal temperature was 100.7. The inguinal lymph node palpation was negative. The chest radiograph obtained displayed   no evidence of an acute cardiopulmonary abnormality. Significant lab findings were an erythrocyte sedimentation rate of 37, white blood cell (WBC) count of 16.8, Glucose of 305 and cultures of the wound obtained in the emergency room revealed Klebsiella ornithinolytica, Enterococcus faecalis and Streptococcus anginosus. Blood cultures were taken in the emergency room and the results were negative.

Routine radiographs performed at our center showed lucency through the medial base of the residual 5th metatarsal could represent a nondisplaced fracture or residual osteomyelitis within the bone.  Also seen was soft tissue air consistent with gas was seen medial to the 4th proximal phalanx. There was no adjacent osseous erosive change to suggest osteomyelitis within the 4th toe (Figure 1). Because of the presence of gas on the x-ray, the plan was to bring the patient the same day to the operating room for resection of 4th ray and incision and drainage of the same area without closure followed by IV antibiotics.

Under general anesthesia and with the use of an ankle tourniquet, utilizing a 4-cm racket incision that incorporated the existing lateral surgical incision, the fourth digit was disarticulated at the fourth metatarsophalangeal joint and sent to pathology.  Deep tissue cultures were obtained in this area. Necrotic tissue was noted to the plantar aspect, and there was a foul smell noted without purulence. All necrotic tissue was removed and the distal aspect of the fourth metatarsal was freed of all soft tissue attachments and utilizing a sagittal saw, the bone was resected at the mid-shaft of the fourth metatarsal. The resected bone was sent to pathology.  The remaining bone of the fourth metatarsal was noted to be firm, and there was no surrounding necrotic tissue. The surrounding areas were probed, and no abscesses were noted. The operative site was copiously lavaged with Betadine-infused saline. Betadine-soaked Iodoform gauze packing was used to fill the void in the 4th metatarsal with a 3cm area remaining opened for drainage. After surgery, he was placed on IV antibiotics that included Zosyn 3.375 gram every 6 hours and Vancomycin 1 gram every 12 hours for the suspected osteomyelitis. Pathologically, the examination revealed acute osteomyelitis of the toe and metatarsal head with the bone margin free from osteomyelitis and the soft tissue margins of amputation were free from acute inflammation. Cultures taken intra-operatively displayed Klebsiella ornithinolytica [1,2,3,4,5,6,7,8] which was susceptible to Zosyn.

For the next 6 days, the patient stayed as an in-patient without complications while the pain diminished, constitutional symptoms of infection disappeared and WBC improved to 8.8. He was discharged after 6 days and sent home on Augmentin for two weeks and seen as an outpatient in the podiatry clinic. Over the next 6 weeks, the patient had no local or constitutional signs of infection while the incision site closed.

Discussion

Raoultella ornithinolytica (formerly Klebsiella ornithinolytica) is a Gram-negative aerobic bacillus which belongs to the family Enterobacteriaceae. However, human infections caused by bacteria of the genus Raoultella are uncommon. A search of the available literature shows only a handful of documented infections with this presentation.  It is likely due to the patient’s history of poorly controlled diabetes, with a history of cocaine and continued tobacco use, that caused a compromise to his immune system. Due to the dusky appearance of his fourth digit as well as gas on the radiographs, it was medically necessary for a partial ray resection of the fourth metatarsal. After the operative procedure, the patient was started on IV vancomycin and IV Zosyn.  After cultures returned patient was switched to Augmentin.

We have described an unusual presentation of bony involvement with soft tissue gas which was a result of an unusual organism. Though infection is rare, Raoultella ornithinolytica can cause significant and possibly limb and life-threatening infection.  As previously stated there are only a handful of cases where this level of destruction has been noted due to this particular organism. It is important as clinicians to remember that patients who have an immunocompromised status may encounter organisms that are out of the ordinary and may require increased care.  Even though this organism is rare the treatment for the resulting gas gangrene is straightforward. We are fortunate that this patient presented to the emergency department when he did. We establish a definitive treatment plan in order to prevent a more aggressive amputation. Unfortunately, do to the sequela of this procedure the patient was left with an unstable forefoot which ultimately led to a transmetatarsal amputation.  The transmetatarsal amputation site healed uneventfully.

References   

  1. Walckenaer E, Poirel L, Leflon-Guibout V, et al. Genetic and Biochemical Characterization of the chromosomal class A β-lactamases of Raoultella (formerly Klebsiella) planticola and Raoutella ornithinolytica. Antimicrob Agents Chemother. 2004;48(1):305–312.
  2. Kanki M, Yoda T, Tsukamoto T, Shibata T. Klebseilla pneumoniae produces no histamine: Raoutella plantico and Raoutella ornithinolytica strains are histamine producers. Appl Environ Microbiol. 2002;68(7):3462–3466.
  3. Ferran M, Yébenes M. Flushing associated with scombroid fish poisoning. Dermatol Online J. 2006;12:15.
  4. Morais VP, Daporta MT, Bao AF, Campello MG, Andrés GQ. Enteric fever-like syndrome caused by Raoultella ornithinolytica (Klebsiella ornithinolytica) J Clin Microbiol. 2009;47(3):868–869.
  5. Solak Y, Gul EE, Atalay H, Genc N, Tonbul HZ. A rare human infection of Raoultella ornithinolytica in a diabetic foot lesion. Ann. Saudi Med. 2011;31(1):93–94.
  6. Hadano Y, Tsukahara M, Ito K, Suzuki J, Kawamura I, Kurai H. Roultella ornithinolytica bacteremia in cancer patients: report of three cases. Intern Med. 2012;51(22):3193–3195.
  7. Hostacká A, Klokocníková Antibiotic susceptibility, serum response and surface properties of Klebsiella species. Microbios. 2001;104:115–124.
  8. Hoshide RR, Chung H, Tokeshi J. Emergence of community-acquired extended-spectrum beta-lactamase Escherichia coli (ESBLEC) in Honolulu: A case series of three individuals with community-acquired ESBLEC bacteriuria. Hawaii Med J. 2011;70(9):193–195.

Issue 11(3), 2018

11 (3), 2018


Intramedullary fixation of distal fibular fractures in a geriatric patient: A case report
by Amanda Kamery DPM, Craig Clifford DPM MHA FACFAS FACFAOM


Navicular dislocation and orthotic management: A case study
by Joshua Young BSc.(Hons), MBAPO Orthotist

Navicular dislocation and orthotic management: A case study

by Joshua Young BSc.(Hons), MBAPO Orthotist1*

The Foot and Ankle Online Journal 11 (3): 2

Navicular dislocation is a rare injury, typically managed by surgical fixation. This case study presents the results of conservative management of navicular dislocation, using a custom foot orthosis, combined with a removable walker boot. At 6 week review the numeric pain rating scale (NRS-11) score was reduced from 8/10 to 3/10. A foot orthosis combined with a removable walker boot may reduce pain in the short term in non-operable navicular dislocation more successfully than a walker boot alone.

Keywords: navicular, navicular dislocation, orthoses, orthotics

ISSN 1941-6806
doi: 10.3827/faoj.2018.1103.0002

1 – Roehampton Rehabilitation Centre, Queen Mary’s Hospital. St George’s University Hospitals NHS Foundation Trust; Opcare, Oxfordshire, UK.
* – Corresponding author: Joshua.Young@stgeorges.nhs.uk


Dislocation of the navicular without fracture is a rare injury [1-3]. A 2015 case study by Singh and colleagues found 16 previously reported cases in the literature [2].  A further case study was published in 2016 [1]. Two other published cases were not identified which gives a total estimate of 20 published cases in the literature to date [4,5].

The mechanics of injury are commonly described as involving pronation, with abduction of the forefoot [6]. Davis and colleagues describe a transient midtarsal dislocation which allows the navicular to dislocate [3]. The navicular may displace in a plantar or dorsal direction, depending on the nature of the injury.  Dhillon and Nagi argue that the injury is never truly an isolated injury as disruption to both the medial and lateral columns of the foot is necessary [6].

Surgical management is usually recommended, typically with temporary Kirschner wire fixation, although other means of fixation may be used [1-3].  Custom foot orthoses have been suggested as a possible treatment option for surgically corrected cases of navicular dislocation which remain painful  however there are no reported cases of purely conservative management of navicular dislocation of which the author is aware [1]. This case report presents a navicular dislocation managed purely conservatively using orthoses due to surgical risk factors which made the subject a poor candidate for surgery.

Case report

A 67-year-old male was referred to see an orthotist in the orthotic service by his orthopedic foot and ankle consultant. The subject had an injury to his left foot 5 months previously sustained during a fall which occurred whilst walking indoors. Initial radiographs and computed tomography scans following the fall show a dislocated navicular and cuboid fracture (Figures 1-4). One month post injury radiographs showed reduced 11 degree calcaneal inclination angle on the left (affected) side compared to 24 degrees on the right, reflecting a reduction in height of the medial longitudinal arch.

Figure 1 Dislocated navicular resting inferior to the sustentaculum tali.

Figure 2 Dislocated navicular resting inferior to the sustentaculum tali.

Figure 3 Cuboid fracture.

Figure 4 Three dimensional CT reconstruction showing dislocated navicular.

A significant factor in the injury was the subject’s body weight which at 2 months following the injury was 161kg (Body Mass Index 50). At the time of assessment in orthotic clinic 3 months later, this had increased to 189kg (Body Mass Index 56). The increased body weight will have increased the ground reaction forces experienced by the foot, and the resultant internal stresses on tissues such as ligamentous tissue which normally help to maintain joint congruency [7,8].

Following two orthopedic opinions, and assessment in a high risk anesthetic clinic, it was agreed to avoid surgery due to the high risk of mortality. It was observed that the talar head was now articulating with the medial cuneiform, forming a pseudo joint.

At presentation in orthotic clinic the subject reported pain as the primary concern. His walking was very limited to short distances indoors, wearing a removable walker boot (Aircast Airselect, Donjoy). He reported pain at an intensity of up to 8 out of 10 (numeric rating scale, NRS-11). A custom ankle foot orthosis (AFO) was considered to limit painful movement within the foot, however this was decided to not be feasible as the subject would struggle to apply or remove this independently [9]. A custom foot orthosis (FO) was prescribed to wear inside the walker boot. The mechanical aim of this was to apply forces to the medial longitudinal arch in an attempt to modify compressive stresses assumed to be occurring at the midfoot and talo-cuneiform pseudo-joint, and tensile stresses assumed to be occurring in soft tissues at the plantar foot [9]. The FO was made from an imprint of the foot in a foam impression box using a computer aided design and manufacture (CAD-CAM) system (Paromed, Neubeuern, Germany). The FO was manufactured using 70 shore material at the heel to midfoot, and softer 50 shore material from the midfoot to the forefoot. A soft 3.2mm grey poron polyurethane foam cover (Algeos, Liverpool, UK) was added. The shape of the FO is demonstrated by the modeling images (Figure 5a-d).

FAOJ_11.3.2 (1)

Figure 5 Custom foot orthosis, medial view (a), lateral view (b), anterior view (c), dorsoplantar view (d).

At 6 week review the subject reported good compliance with wearing the FO within the walker boot. Using the 11 point numeric pain rating scale (NRS-11), pain intensity during walking was reported to be reduced from 8/10 to 3/10.

Discussion

This case study presents the results of conservative management of an unusual foot injury. A custom FO, combined with a walker boot, reduced pain intensity in the short term. Pain was still present while using the walker boot only. The reported reduction in pain following addition of the FO may imply that the FO was able to modify stresses in the midfoot, even in the presence of very high body weight, in order to be effective. FOs are rarely used for this specific application due to the rarity of the injury, however they may be combined  with walker boots to manage Charcot foot which is also associated with major change of the midfoot architecture. Limitations of this study include a lack of further outcome measures, and possible bias incurred by the treating clinician administering the NRS-11 pain scale. This case study illustrates the possibility that even major changes in the bony structure of the foot, which are symptomatic, may be manageable to some extent conservatively using foot orthoses.

Acknowledgements

The author would like to acknowledge Dominic Nielsen, consultant orthopaedic surgeon, for his comments on the paper.

References

  1. Ansari MAQ. Isolated complete dislocation of the tarsal navicular without fracture: A rare injury. Ci Ji Yi Xue Za Zhi. 2016;28(3):128-131.
  2. Singh VK, Kashyap A, Vargaonkar G, Kumar R. An isolated dorso-medial dislocation of navicular bone: A case report. J Clin Orthop Trauma. 2015;6(1):36-8.
  3. Davis AT, Dann A, Kuldjanov D. Complete medial dislocation of the tarsal navicular without fracture: report of a rare injury. J Foot Ankle Surg. 2013;52(3):393-6.
  4. Hamdi K, Hazem BG, Yadh Z, Faouzi A. Isolated dorsal dislocation of the tarsal naviculum. Indian J Orthop. 2015;49(6):676-9.
  5. Dias MB, Zagonel B, Dickel MS, Talheimer JA, Argenton IS, et al. Isolated dislocation of the tarsal navicular without fracture: Case report. Trauma Cases. 2016,Rev 2:045
  6. Dhillon MS, Nagi ON. Total dislocations of the navicular: are they ever isolated injuries?. J Bone Joint Surg Br. 1999;81(5):881-5.
  7. Browning RC, Kram R. Effects of obesity on the biomechanics of walking at different speeds. Med Sci Sports Exerc. 2007;39(9):1632-41.
  8. Pamukoff DN, Lewek MD, Blackburn JT. Greater vertical loading rate in obese compared to normal weight young adults. Clin Biomech (Bristol, Avon). 2016;33:61-65.
  9. International standards organization. ISO 8549-3, Prosthetics and orthotics – Vocabulary – Part 3: Terms relating to external orthoses. 1989.

Intramedullary fixation of distal fibular fractures in a geriatric patient: A case report

by Amanda Kamery DPM1*, Craig Clifford DPM MHA FACFAS FACFAOM2

The Foot and Ankle Online Journal 11 (3): 1

Intramedullary rod fixation is presented as a viable treatment option for distal fibular fractures in the geriatric population. This technique leads to a reduction in wound complications, hardware irritation, procedure time and need for subsequent surgeries as seen with traditional open reduction internal fixation for distal fibular fractures in higher-risk patients.

Keywords: ankle fracture, trauma, geriatric, open reduction

ISSN 1941-6806
doi: 10.3827/faoj.2018.1103.0001

1 – Franciscan Foot and Ankle Institute- St Francis Hospital, Federal Way, WA PGY-3
2 – Residency Director, Franciscan Foot and Ankle Institute- St Francis Hospital, Federal Way, WA
* – Corresponding author: akamery@kent.edu


Geriatric patients are at an increased risk for sustaining ankle fractures due to increased fall rate and decreased bone density. Surgical repair for such injuries is often complex, due to the standard large incision and relatively bulky fixation which is necessary in the geriatric patient due to their generally poor bone stock [1]. This traditional form of fixation carries a complication rate of up to 30% [2]. Additionally, wound healing complications and hardware irritation is more common in this population due to a poor soft tissue envelope, with wound infection rates ranging from 26-40% [3]. Commonly, subsequent surgeries are necessary to remove hardware or to perform wound debridements [4]. As it is well documented that surgical morbidity increases in this population, it is important to utilize techniques and fixation methods that limit subsequent encounters. In this case report, we present intramedullary fixation for distal fibular fractures as a viable option for the geriatric population.

Case  Report

The patient is a 94-year-old male who presented 5 days after a fall with a Weber B, slightly comminuted, left distal fibular fracture (Figure 1a). Due to the unstable nature and slight displacement of the fracture, surgical intervention with an intramedullary fibular rod was chosen. Intra-operatively under general anesthesia, excellent anatomic reduction was noted after placement of the rod and one syndesmotic screw (Figure 1b).

At 2 weeks postoperatively, the posterior splint and skin staples were removed. The patient transitioned to protected heel touch weight-bearing for 4 weeks. He resumed regular activity and normal shoe wear at 6 weeks postoperatively. There were no wound healing complications or hardware irritation noted throughout the postoperative course. At 12 months follow up, patient reported no ankle pain or limitations in activities of daily living (Figures 2a-b).

 

Figure 1 AP ankle radiograph showing Weber B fracture with slight comminution and displacement (a). Two weeks postoperative AP radiograph showing excellent anatomic reduction with fibular rod and syndesmotic screw (b).

 

Figure 2 Twelve months post operative AP (a) and lateral (b) radiographs showing excellent bony consolidation of fracture fragments and adequate anatomic reduction.

Discussion

Treatment of distal fibular fractures in geriatric patients have an increased risk for postoperative complications which can lead to wound healing issues and subsequent surgeries. It is important to utilize techniques and fixation methods that limit subsequent encounters in order to decrease surgical morbidity in this cohort. The intramedullary fibular rod is an excellent alternative to traditional ORIF in the geriatric population. Our case example demonstrates an ideal patient for this technique, including successful anatomic realignment and uneventful postoperative course.

References

  1. Mitchell JJ, Bailey JR, Bozzio AE, Fader RR, Mauffrey C. Fixation of distal fibula fractures: an update. Foot Ankle Int. 2014;35(12):1367-1375.
  2. Lamontagne J, Blachut PA, Broekhuyse HM, O’Brien PJ, Meek RN. Surgical treatment of a displaced lateral malleolus fracture: the antiglide technique versus lateral plate fixation. J Orthop Trauma. 2002;16(7):498-502)
  3. Höiness P, Engebretsen L, Stromsoe K. The influence of perioperative soft tissue complications on the clinical outcome in surgically treated ankle fractures. Foot Ankle Int. 2001;22(8):642-648.
  4. Lee YS, Huang HL, Lo TY, Huang CR. Lateral fixation of AO type-B2 ankle fractures in the elderly: the Knowles pin versus the plate. Int Orthop 2007;31:817–821.

 

Issue 11(2), 2018

Issue 11 (2), 2018


Progression of a digital or partial ray amputation to transmetatarsal amputation and below knee amputation: Time frames and associated comorbidities, a three-year retrospective study
by Carmen Bruno DPM, Susan Wiersema DPM, Nneka Meka DPM


The vacuum phenomenon in the ankle joint: Air bubbles on CT
by Christopher R. Hood JR. DPM, Wesley A. Jackson DPM, Robert C. Floros DPM, David A. Bernstein DPM


Operating on patients with complex regional pain syndrome
by Ryon Wiska DPM, Lawrence Fallat DPM FACFAS


Single lateral incision for a triple arthrodesis
by Alan Kidon DPM AACFAS, Elizabeth Sanders DPM AACFAS FACFAOM, Mark Mendeszoon DPM FACFAS FACFAOM