Tag Archives: Foot ulcers

Foot anthropometrics in individuals with diabetes compared with the general Swedish population: Implications for shoe design

Tables Supplement

by Ulla Hellstrand Tang1,2 , Jacqueline Siegenthaler2, Kerstin Hagberg1,2, Jon Karlsson1, Roy Tranberg1

The Foot and Ankle Online Journal 10 (3): 1

Background: The literature offers sparse information about foot anthropometrics in patients with diabetes related to foot length, foot width and toe height, although these measurements are important in shoe fitting. A poorly fitted shoe is one of many contributory factors in the development of diabetic foot ulcers. The purpose of this study was to describe the foot anthropometrics in groups of patients with diabetes, in groups representing the general population and to explore whether foot anthropometrics differ between patients with diabetes and the general population.
Method: Foot anthropometrics (foot length, foot width and maximum toe height) was measured in 164 patients with diabetes, with and without neuropathy (n = 102 and n = 62 respectively). The general population was represented by 855 participants from two sources.
Results: Foot length, foot width and toe height varied (220-305 mm; 82-132 mm and 15-45 mm respectively) in the diabetic group and in the group representing the general population (194-306 mm; 74-121 mm and 17-31 mm respectively). Age, gender and BMI influence the foot anthropometrics, however, when adjusting for theses variables the index foot length/width was lower (2.58) in patients with diabetes without neuropathy vs. controls (2.63), p = 0.018. Moreover, patients with diabetes with neuropathy had wider feet (98.6 mm) compared with the controls (97.0 mm), p = 0.047.
Conclusions: The individual variations of foot length, foot width and maximum toe height were large. The impact of gender on foot anthropometrics was confirmed and the impact of age and BMI were shown. Patients with diabetes seemed to have a wider forefoot width and a lower foot length to foot width ratio compared to the controls.

Keywords: foot deformities, foot ulcers, footwear, prevention, shoe design, shoe lasts, diabetes, diabetic foot, anthropometrics

ISSN 1941-6806
doi: 10.3827/faoj.2017.1003.0001

1 – Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
2 – Department of Prosthetics and Orthotics, Sahlgrenska University Hospital, Gothenburg, Sweden.
* – Corresponding author: ulla.tang@vgregion.se


The biomechanical interaction between the foot and the shoe, three-dimensional appearance of the foot and the relationship between foot anthropometrics and the shoe have been shown to be important in the prevention of diabetic foot ulcers (DFU) [1-3]. In Sweden at the present time, foot measurements are not mandatory when patients are provided with therapeutic footwear at a department of prosthetics and orthotics (DPO). However, foot measurements are essential for the construction of the last upon which the shoe is created. In the 1950s, the Swedish Shoe Industry’s Research Institute (SFI) stated that the length and width of the foot should be measured before recommending any shoe to a customer [4]. Based on 8,000 foot measurements of Swedish men, the SFI constructed a standardized system, “the SFI last system”, which aimed to provide the majority of Swedish men with well-fitting shoes. This system included six different types of lasts, specified in three dimensions.

In patients with diabetes, the loss of protective sensation (peripheral neuropathy), together with poorly fitting shoes, increases the risk of developing DFU [3, 5, 6]. The risk is further increased by the presence of other risk factors, such as peripheral angiopathy, peripheral neuropathy, foot deformities, skin pathologies, previous ulcers or amputation or osteoarthropathy, Figure 1 [7, 8]. Based on the recommendations of the International Working Group on the Diabetic Foot (IWGDF), patients with diabetes, should have access to well-fitting shoes if they are at risk of developing DFU [5, 9]. Early prevention, together with well-fitting shoes, podiatry and access to specialists, has been shown to be successful. Bus and van Netten recently suggested that the target should be to reduce the incidence of DFU by 75% [10]. Their suggestion is based on a review of the scientific literature regarding the prevention of DFU recurrence. These authors found that interventions that included pressure-relieving therapeutic footwear, surgical interventions, home monitoring of foot temperature and, most importantly, adherence to treatment could produce a 75-80% decrease in DFU risk. The provision of adequate footwear is considered successful when it corresponds in every aspect to guidelines and recommendations relating to DFU prevention and care; i.e. a) when the patient finds the shoe acceptable, b) when the shoe has a design that accommodates all three dimensions of the foot and c) when the function of the shoe is satisfactory [9, 11-15]. A shoe that does not accommodate the length, width and height of the foot will be a potential risk factor for the onset of DFU. It has also been suggested that other factors, such as the patient’s age, gender and body dimensions expressed as body mass index (BMI), play an important role in shoe fitting [16-23].

Figure 1 The Swedish foot ulcer risk classification system. The one-page guideline illustrates the risk classes, the symptoms and the regional recommendations regarding interventions with podiatry, regular controls and footwear/orthotics [7].

In Sweden, the prescription of footwear for patients with diabetes at risk of developing DFU follows national and regional guidelines and patients are frequently referred to a certified prosthetist and orthotist (CPO) or an orthopaedic shoemaker for the prescription of adequate footwear [7]. The aims of the study were to describe the foot anthropometrics in groups of patients with diabetes and in groups representing the general population and to explore whether foot anthropometrics differ between patients with diabetes and the general population.

Method

Study design

This retrospective cohort study examined and compared foot anthropometrics (foot length, foot width and maximum toe height) in a group of patients with diabetes, Group D (n=164), with those of a control group of participants without known diabetes, Group C (n=855), representing the general population (Figure 2).

Figure 2. Study population. Presentation of the number of patients included in the two study groups derived from studies of patients with diabetes and studies of foot anthropometrics (the control group). The year when the measurements were obtained are shown in the figure.

Participants

A total of 1,019 participants were included in the present study. All patients in Group D were referred to a DPO by a medical doctor. Their feet were recognised as being at risk of DFU and the patients were provided with therapeutic footwear or insoles at the DPO. The participants have previously been described [24, 25]. Group D was split into two sub-groups, one comprising patients with peripheral neuropathy (DN) and one comprising patients without neuropathy (DD), Figure 2.

Group C comprised participants from two sources. One group consisted of participants from unpublished research from the SFI, Group C1. These data are stored at ArkivCentrum in Örebro, Sweden. The other group consisted of participants that have previously been presented by Hansson et al., Group C2 [26].

Group D

Foot anthropometrics, age and gender in Group D were registered by nine experienced CPOs. All patients were at risk of developing DFU according to the Swedish DFU risk classification system (Figure 1) [7, 8]. The patient’s body height and weight were self-reported. Neuropathy was diagnosed following international recommendations using a set of measurements [27, 28]. In detail, neuropathy was considered present if at least one of the following tests demonstrated a positive finding a) the 10 g monofilament test, vibration test using a tuning fork C128 Hz, the slight touch of a pencil, or awareness of different positioning of the hallux or b) a tingling or numb feeling in the feet, a positive Ipswich Touch Test or self-reported answers from the patients that their feet were currently less sweaty compared with recent years [27-29]. Forty-two (58%) of the women and 60 (66%) of the men had neuropathy. A total of 51 of the 164 (31%) patients were diagnosed with diabetes type 1.

Control Group C1

Foot anthropometrics, age and gender were registered in Group C1, (n=488). A randomly selected cohort, 200 women and 200 men respectively, from a total of 2,382 (546 women and 1,836 men) individuals were analysed. The measurements were collected in Sweden 1972-1977 by the SFI [30, 31]. The women included in the cohort worked at shoe factories or offices and the men in the cohort were in the military service. The measurements of the conscripts were made by three different investigators in a project managed in collaboration with the Swedish Defence Materiel Administration [30]. The foot measurements of the retired persons and the 200 women were registered and examined by one investigator employed at the SFI. A further set of 88 measurements, registered by SFI, from retired persons was included.

Control group C2

Foot length, foot width, age, gender, height and weight were registered in Group C2 [26]. The foot anthropometrics in Group C2, 262 women and 105 men, were measured by trained personnel in 2006. Body height was measured using a rigid measuring tape attached to the wall. Body weight was measured with a digital measurement device with an accuracy of 0.1 kg. The raw data were obtained from Skövde University and Chalmers University of Technology, Gothenburg, Sweden [26].

Foot anthropometrics

The definition of foot length and width used in present study is described in Table 1 (all tables are included in attached Supplement PDF) and illustrated in Figure 3. The equipment, measurement and methods used in the sub-groups are reported in Table 1, together with information on the accuracy of the measurements. In Group D, foot length and foot width were measured with a standardised calliper (Fotmått, model Hyssna, Jerndahls Skinn & Läder; Kumla, Sweden, and Footy, article number 500210, Brunngård, Borås). In Group C1, a special foot measurement apparatus (Figures 4 and 5) was used to measure foot length and ball width. The foot of the participants in Group CI were fixed in the foot measurement device and aligned in a local coordinate system with the foot length axis (line) projected from the posterior part of the middle of the heel through an interdigital point between digit 1 and digit 2. It is noteworthy that the measurements of foot length using this technique placed the heel in an 18 mm heel height position and the length measured was the projected foot length, Figure 3. The projected foot length is approximately 0.6 mm shorter than a measurement obtained with zero heel height. The only exception from this routine was the measurement of foot length and ball width in 97 conscripts, year 1975, and in the group of retired persons. These measurements were obtained using a special body calliper device, an anthropometer [32]. In Group C2, a rigid measuring tape was used to measure foot length and foot width with an accuracy of ± 2 mm. In Group C1, the measurements of the width of the forefoot, made by the SFI, are by definition the ball width, a line from the inner ball point to the outer ball point, Figure 3. To calculate a comparable measurement of foot width, perpendicular to foot length, the following equation was used: f(fw)= cos α * bw where fw is the foot width, α is the ball angle and bw is the ball width. The maximum toe height, a measurement for identifying the foot deformity “hammertoes” (Figure 6), was introduced and measured using a ruler. The SFI reported a standard error of the mean of 0.18 mm [4] for the toe height measurement and Hellstrand et al. found a mean difference of 0.5 mm [25]. In Group D, digits 1-5 were measured and, in Group C1, toe height (digits 2-4) was measured in 200 women.

Figure 3 Definition of foot measurements. Foot length: the line, parallel to the foot axis, from the posterior heel point to the most distal toe point. The line passes through the centre of metatarso-phalangeal joint 2. Foot width: measured to the foot axis perpendicularly as the projected length of the distance in the forefoot through the centre of the first metatarsal head to the lateral side. Ball width: the line from the inner to the outer ball point. Ball angle: the space between the two intersecting lines “foot width” and “ball width”.

Figure 4 Foot measuring apparatus. The foot measurement apparatus was constructed to measure 21 foot anthropometrics (length, width, heights and angles). It was developed by Nils Haraldsson and used by the Swedish Shoe Industry’s Research Institute. Between 1940-1990, the feet of 16,000 people in Sweden were measured. The right foot was placed naked and with the planta horizontally on the measurement device and fixed with a metal plate between the hallux and the 2nd toe. The posterior part of the heel rested against a bar. Subjects stood with their weight equally distributed between both feet. The heel height was fixed at 18 mm. Foot length was measured with a bar mounted perpendicular to a longitudinal scale. A turnable scale mounted on the longitudinal scale was used for measurements of ball width. All measurements at the SFI were performed with the same measurement device. Photographer Curt Götlin 1951/Örebro stadsarkiv. 

Figure 5 Foot measuring apparatus in detail. Foot measurement apparatus developed by Nils Haraldsson and used by the Swedish Shoe Industry’s Research Institute. Between 1940-1990, the feet of 16,000 people in Sweden were measured. Photographer Curt Götlin 1951/Örebro stadsarkiv. Homepage available 2016-04-22 The apparatus can be seen at the Kumla Skoindustri Museum. 

Patients reported experience measure

A subgroup (n = 97) of the patients with diabetes was interviewed by a research assistant, following a structured protocol, regarding how much they had used the footwear and how they experienced wearing the footwear

Statistical analysis

General demographics and the foot anthropometrics (length, width and maximum toe height) in the four groups are reported using the mean and standard deviation (SD). Due to dependency between the right and the left foot, only the right foot was analysed. Measurements with invalid data were excluded. Differences between groups regarding foot anthropometrics were examined in the following three comparisons.

Comparison 1 examined whether there were differences between groups (DN, DD, C1 and C2) in the dependent variables (foot length, foot width, indexFL/FW and maximum toe height respectively). One-way analysis of variance (ANOVA) was used, followed by multiple comparisons. By using residual plots and Q-Q plots, the assumptions of the analyses were analysed. The variable maximum toe height had minor deviations from the assumptions, with a skewed distribution of the residuals and the logarithmic value was therefore used for all further analysis.

Comparison 2 examined whether there were differences between groups regarding the dependent foot variables, considering the covariates of age and gender.

Comparison 3 examined whether there were differences between groups regarding the dependent foot variables, considering the covariates of age, gender and BMI.

In comparisons 2 and 3, the covariates were added in a linear mixed model with fixed effects with factors (study groups and gender) and quantitative variables (age and BMI). The above-mentioned foot anthropometrics were dependent variables. Differences between groups were corrected for differences regarding the covariates of age, gender and BMI. Group C2 was excluded in comparison 2 in terms of the maximum toe height analysis (toe height had not been measured) and Group C1 was excluded in comparison 3 (height and weight had not been measured).

Excel 2010, SPSS 22 and SAS version 9.3 (SAS Institute Inc.Cary, N.C., USA) software were used. The SAS procedure, MIXED with LSMEANS and ESTIMATE statements, statistical tests and comparisons of population marginal means were used in the comparative analyses. In the following text, the term “analysis of covariance” is used to describe the method.

Results

The demographics showed that participants with diabetes were older and had a higher BMI (women: 61 ± 14.4 years BMI 26.7 ± 4.9; men: 63 ± 13.7 years BMI 28.7 ± 5.2) compared with the participants representing the general population (women: 41 ± 16.5 years BMI 23.1 ± 3.4; men: 34 ± 17.9 years BMI 24.1 ± 3.5). A full presentation of the participants is given in Table 2. In Table 3, the details (HbA1c and duration) of patients with diabetes are presented.

The analysis of foot anthropometrics was based on 164 measurements in Group D and 855 measurements in Group C, Figure 2. The exploration of foot anthropometrics revealed that, among women, the foot length varied from 245.4 ± 10.9 mm (Group DD) to 242.3 ± 12.3 mm (Group C2) and the width varied from 96.8 ± 4.9 mm (Group DD) to 90.9 ± 7.7 mm (Group C1), Table 4. Women with diabetes with neuropathy had the largest toe height (25.8 ± 4.6 mm).

The foot length among men varied from 271.4 ± 15.2 mm (Group DN) to 262.7 ± 13.7 mm (Group DD). Moreover, the width varied from 105.8 ± 7.9 mm (Group DN) to 98.8 ± 5.7 (Group C1). Men in Group DN had the largest toe height (28.3 ± 5.7 mm).

The individual variation in foot anthropometrics in patients with diabetes was: foot length (220-305 mm), foot width (82-132 mm) and toe height (15-45 mm) and the variation in the control group was foot: length (194-306 mm), foot width (74-121 mm) and toe height (17-31 mm).

The first comparison of differences between groups revealed that patients in Group DN had 11.0 mm longer feet compared the controls in Group C2 (p ≤ 0.001). The controls in Group C1 had 5.5 mm longer feet than the controls in Group C2 (p ≤ 0.001). Foot width in patients with and without neuropathy was wider (101.5 mm and 99.6 mm respectively) compared to the controls ((94.7 mm and 94.4 mm respectively, (p ≤ 0.001). Maximum toe height was higher in patients with diabetes and neuropathy (26.9 mm) compared with the controls in Group C1 (25.2 mm) (p ≤ 0.001).

In the second comparison, considering the effect of age and gender on foot anthropometrics, only the indexFL/FW was unaffected by age and gender and the covariate of age did not affect foot length. However, regarding foot width, both men and women had an estimated annual increase in width of 0.085 mm/year and men generally had 9.0 mm wider feet than women. Maximum toe height was affected in a similar way. Men had a 0.09 mm higher maximum toe height compared with women. With age, the increase in toe height was 0.03 mm annually. Group DN had a larger toe height (25.5 mm) than Group DD (24.4 mm), p = 0.049. Furthermore, Group DD had a lower toe height than Group C1 (27.1 mm), p ≤ 0.001. Foot width, adjusted for age and gender was wider in patients with diabetes compared to the controls and accordingly the indexFL/FW was higher in the groups representing the general population compared to the diabetics.

The third comparison revealed that gender and BMI affected foot length and foot width. With every unit increase in BMI, foot length and foot width increased by 0.6 mm. Adjusting for these covariates, foot width still differed comparing Group DN with Group C2 (98.6 mm vs. 97.0 mm), p = 0.047. The indexFL/FW differed when comparing Group DD (2.58) with Group C2 (2.63) p = 0.018.

Patients reported experience measure

Eighty-six out of a total of 97 patients (response rate 89%) participated in the interview at three months after the visit to the DPO (Table 6). Thirty patients had been provided with footwear and among those 70% had used their therapeutic footwear often or all the time and 76% stated they were content or very content with the footwear. Twenty-nine patients made comments, Table 7. Seven of the comments were categorized as complaints related to the footwear, such as “The shoe appears to be too large”. Ten patients reported that the use of footwear and/or foot orthoses was dependent on the season and location (indoors or outdoors).

Discussion

To our knowledge, this is the first study presenting foot anthropometrics in patients with diabetes and the general population in terms of foot length, foot width, indexFL/FW and maximum toe height. Foot length, foot width and toe height varied in the diabetic group (220-305 mm; 82-132 mm and 15-45 mm) and in the group representing the general population (194-306 mm; 74-121 mm and 17-31 mm). Patients with diabetes had wider feet compared to the participants representing the general population. The main finding is that several factors affect foot anthropometrics and include the presence of diabetes, neuropathy, gender, age and BMI.

The maximum toe height measurement is of special interest when it comes to preventing foot ulcers in patients with diabetes (Figure 6). Large toe height is typical of a hammer-toe deformity. This deformity with dorsal flexion of the metatarsal phalangeal joint and plantar flexion of the interphalangeal joints, causes high peak pressure to certain areas of the toe [33]. Measurements of maximum toe height provide important information and guidance in the selection of a shoe with an appropriate toe box height relative to the maximum individual toe height. A threshold value of 25 mm is suggested, based on toe box heights common in off-the-shelf shoes, ranging from 22-26 mm [34]. The range for toe box height and the suggested threshold value correspond well to the toe box heights (24.5-28.5 mm) standardised in the SFI lasts for men with a foot length of 260 mm [4]. Patients with a toe height of greater than 25 mm should be identified and provided with shoes with a toe box height that allows the toes to move without limitation [35].

Figure 6 Hammertoe deformity. A hammer toe deformity with areas of of high pressure indicated by the red areas. The structural changes is a combination of the flexion of the the interphalangeal joints and the extension of the metatarsal phalangeal joints.

Foot anthropometrics appeared to be affected by age. Based on the presented data, the toe height age coefficient of 1.003 indicates an annual increase in maximum toe height of 0.3% (Table 5). A simulation of an increment in toe height implies that a person who, at the age of 20, has a maximum toe height of 25 mm would, at the age of 40 years, have a toe height of 27.8 mm (a total increase of 10.4%). At the age of 80 years, the maximum toe height would be 29.2 mm (a total increase of 15.5%).

The effect of age on foot width was not statistically significant when all three covariates (age, gender and BMI) were included in the model. However, Tommassoni et al. measured ball forefoot circumference as a combined width and height measurement and found an increase with age [22]. In their study, older women (65-75 years) had a larger forefoot circumference, 235.4 ± 8.3 mm, compared with. younger women (25-35 years) 217.2 ± 11.5 mm. Tommassoni found similar results for older men (256.4 ± 7.8 mm) vs. younger men (242.1 ± 17.4) [22]. A well-fitting shoe, with good function, should correspond to the forefoot width and the forefoot circumference to avoid pressure-induced DFU in the forefoot. Previous findings shows that unfortunately, wearing ill-fitting shoes that are too narrow, are common [36].

The CPOs and orthopaedic shoemakers play an important role in guiding patients towards choosing an appropriate shoe. In this context, foot measures obtained on regular basis, are a good starting point for a discussion between the CPO and the patient regarding shoe lasts that fit the foot according to foot length, foot width and toe height.

Not surprisingly, gender was a covariate of importance to explaining the variation in foot anthropometrics in terms of foot length and foot width. Both measurements, length and width, were larger in men than in women (comparison 2, Table 5) and the results confirm previous findings of gender differences, showing that men in generally have longer and wider body segments than women [22, 37-39]. Several shoes are designed for unisex purposes and it is reasonable to consider whether shoes manufactured on such lasts actually fit both men and women [40]. The findings in the present study show gender differences for all three dimensions of the foot.

Possible systematic errors in measurement technique (tools and personnel) and/or sample bias might affect the validity of the data. The foot measurement apparatus developed and used by the SFI was designed to obtain robust measurements on thousands of people in Sweden half a century ago. These measurements had high precision   (Table 1). The measurement error reported in Group C1 was small (± 0.14 mm) in terms of the foot length. Measurements and the accuracy of foot length and foot width, measured with a rigid measuring tape in Group C2 was acceptable ± 2 mm [26]. The  mean difference regarding foot length and foot width measurements in Group D was (0.2 and 0.7 mm respectively), which indicates that the method used was reliable [25]. The method for measuring foot width was similar in Group D and Group C2. The foot width in Group C1 was derived from the ball width measurements, Table 1 and Figure 3 [30]. Due to the high accuracy of the ball width measurements (± 0.06 mm) the calculated foot width measurement is considered to be high [4]. The measurement error in toe height measurement was acceptable in Group C1 (± 0.18 mm) and in Group D (a mean difference of ± 0.5 mm).

The lack of anthropometric foot data of greater sample sizes was the reason for the use of several data sources, some of older date. The data from SFI was considered to be of high quality as the foot anthropometrics in Group C1 was obtained by the use of a well-established technique with high accuracy [30-32, 37, 41].

A certain question of interest is whether the participants born at later date, in general, had longer body segments and longer feet. This might be an expression of the secular trends [4, 42-44]. In that case, a consequence should be that the general population born in the 1960s (Group C2) would have longer feet than the older population born in the 1930s (Group C1). However, no such difference was supported in the present data.

Patients with diabetes and neuropathy appeared to have longer feet (comparison 1) and higher toe height (comparison 2). However, due to multiple comparisons the p-value is not convincing and this finding need to be confirmed in larger studies. Moreover, the test of assessing neuropathy in current study did not discriminate between slight and severe expressions of neuropathy. It is reasonable to expect that imbalance of muscle forces leading to foot deformities is related to the severity of neuropathy.

Patients reported experience measure

The majority of the patients who received therapeutic footwear used the footwear frequently and were satisfied with the footwear. However, the standardized routine used in the interview has not been validated. It is suggested that a combination of interviews and validated surveys should be used in coming studies [45]. Bus and van Netten showed that adherence to the prescribed intervention is a primary factor for successful treatment of DFU, i.e. the provision of adequate footwear is only successful if the patient uses the shoes [10]. Consequently, the patient must find the shoe suitable according to his/her preferences, and the shoe must have a shape and function suitable for the foot, considering the general recommendations in terms of DFU prevention and care [9, 11]. This is a challenge as, besides being an assistive devices [46], footwear is part of the patient’s personal attributes and identity.

Statistical considerations

The results of the three comparisons (ANOVA analysis and the following two analyses of covariance) were not adjusted for multiple comparisons, i.e. some of the differences may have appeared by chance. Therefore, the p-value increased when the covariates of age, gender and BMI were included in the model. Prospective longitudinal studies, including larger cohorts, are suggested to confirm the findings of the present study. All four study groups were included in the first comparison of differences in foot anthropometrics between groups. However, due to lack of data of height and weight, C1 was excluded in comparison 3, the analysis in which BMI was considered. In the comparison of maximum toe height, Group C1 was represented by a cohort of 200 women and Group C2 was not included due to lack of relevant data.

Shoe design

Large individual diversity, in terms of foot length, width and maximum toe height, was present in patients with diabetes with and without neuropathy. Moreover, age, gender and BMI influence the foot shape of individuals. All these aspects need to be considered in shoe design. The shoe last must correspond to the three-dimensional appearance of the foot, allowing the forefoot and the toes to move [36, 47].  Appropriate fit at the hindfoot and midfoot is also essential to ensure that the shoe stays on the foot [4].

One basic prerequisite for functional shoe design is an appropriate knowledge of foot biomechanics [5, 36, 48]. This is of utmost importance when manufacturing shoes for patients at risk of developing DFU. In order to enhance the shoe-fitting procedure, standardised routines including regular measurements of foot anthropometrics are suggested. This should preferably be supplemented by a shoe measurement specification from the manufacturer. Moreover, a thorough documentation of foot anthropometrics in patient’s medical record would facilitate a long-term provision and follow-up.

To highlight the need for standardisation, the following example of shoe length in relation to foot length is presented. The recommendation for how much longer a shoe should be in relation to the longest toe, found in the literature, varies and ranges from 10 to 20 mm [35, 49]. In clinical practice in Sweden, an extra length of 10 mm is recommended in relation to the foot length of adults, measured in a weight-bearing position [50].

The indexFL/FW needs to be rediscovered and used in shoe fitting. This measurement was recommended by the SFI and was used in shoe shops in the 1950s to 1970s, before an appropriate shoe last was chosen for the customer. The indexFL/FW gives a two-dimensional ratio, which is of great interest and assistance before a suitable last type is selected for patients [4, 47, 49]. When custom-made orthopaedic shoes are required a further set of measurements are needed [4].

In the development of good practice to prevent DFU, some attempts have been made to structure the provision of footwear and therapeutic footwear [35, 51]. Dahmen et al. developed a matrix of the features to be included in a therapeutic shoe, e.g. rocker bar, outsole, shaft flexibility, shaft height, insole and heel counter, corresponding to the identified risk factors for the onset of DFU. These risk factors were loss of protective sensation, autonomic dysfunction, limited joint motion, hollow-claw foot, Charcot deformity and hallux amputation [11, 52]. A limitation in the matrix was the lack of foot anthropometrics, such as length, width, the indexFL/FW or maximum toe height. However, length measurement was included in the footwear assessment tool presented by Barton et al., but this tool did not include the width or maximum toe height [51].

Conclusion

The individual variations of foot length, foot width and maximum toe height were large. The impact of gender on foot anthropometrics was confirmed and impact of age and BMI was found. Patients with diabetes seemed to have wider forefoot width and a lower foot length/foot width ratio compared to the controls. Standards for measurements of foot length, foot width and toe height should be developed and used at the DPOs. Accordingly, shoes designed for patients with diabetes should include the same standardised information as the foot measurements.

Declarations

Abbreviations

BMI; body mass index, DFU; diabetic foot ulcers, CPO; certified prosthetist and orthotist, C; control, DPO; department of prosthetics and orthotics, D; diabetes, IWGDF; International Working Group on the Diabetic Foot, SD; standard deviation, SFI; the Swedish Shoe Industry’s Research Institute

Acknowledgement

The authors would like to thank all the personnel at ArkivCentrum Örebro län, Örebro stadsarkivs bildarkiv and Skoindustrimuseet in Kumla for their contribution of data and pictures. We are also grateful for the collaboration with Erik Brolin, Chalmers University of Technology, Gothenburg, Lars Hanson at the University of Skövde and Chalmers University of Technology, Gothenburg, and Dan Högberg at the University of Skövde. We would also like to thank all the patients for their contribution to the study. Without the help of all the co-workers at the DPO Sahlgrenska University Hospital, Gothenburg, the DPO Södra Älvsborgs Sjukhus, Borås, the DPO NU-sjukvården, Trollhättan/Uddevalla, and the DPO Skaraborgs Ortopedservice AB, Skövde, all situated in the Västra Götaland Region in Sweden, this study would never have been possible; thank you all. Finally, we would like to thank Pontus Andersson for the illustration.

Funding

This research was supported by Stiftelsen Promobilia, Stiftelsen Skobranschens Utvecklingsfond, the Research and Development Council of the County of Göteborg and Södra Bohuslän, the Health & Medical Care Committee of the Västra Götaland Region, Stiftelsen Felix Neubergh, Stiftelsen Gunnar Holmgrens Minne, IngaBritt & Arne Lundbergs Forskningsstiftelse, Adlerbertska forskningsstiftelsen, Diabetesfonden, the Gothenburg Diabetes Association and Sveriges Ortopedingenjörers Förening.

Availability of data and material

The data sets supporting the conclusion of this article are included in the article.

Authors´ contribution

UT designed the study, researched the data, contributed to discussions, and wrote the manuscript. JS and RT designed the study, researched the data, contributed to discussions, reviewed and edited the manuscript. KH and JK contributed to discussions, reviewed and edited the manuscript.

Authors´ information

UT and JS are certified prosthetists and orthotists at the department of Prosthetics and Orthotics, Sahlgrenska University Hospital. Moreover, UT is a podiatrist. KH is registered physiotherapist at the department of Prosthetics and Orthotics, Sahlgrenska University Hospital and Associate Professor at the department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University. JK is chief physician at the department of Orthopaedics, Sahlgrenska University Hospital and Professor at the department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University. RT is certified prosthetists and orthotists at Lundberg Laboratory for Orthopaedic Research, at Sahlgrenska University Hospital. All are situated in Gothenburg, Sweden.​

Competing interest

The authors declare that they have no competing interests.

Consent for publication

Not applicable.

Ethics approval consent and permission to participate

The study was approved by the Gothenburg Regional Ethical Review Board (299-07, 461-12 and 1041-13). Patients were informed of the study design before they provided written consent.

References

  1. Pecoraro RE, Reiber GE, and Burgess EM. Pathways to diabetic limb amputation. Basis for prevention. Diabetes Care 1990; 13: 513-21.
  2. Litzelman DK, Marriott DJ, and Vinicor F. The role of footwear in the prevention of foot lesions in patients with NIDDM. Conventional wisdom or evidence-based practice? Diabetes Care 1997; 20: 156-62.
  3. Reiber GE, Vileikyte L, Boyko EJ, Aguila Md, Smith DG, Lavery LA, et al. Causal pathways for incident lower-extremity ulcers in patients with diabetes from two settings. Diabetes Care 1999; 22: 157-62.
  4. Nohrlander Å. Foten, lästen och skon. SFI-systemet för herrskor. Stockholm: Emil Kihlströms Tryckeri. 1954.
  5. Schaper NC, Van Netten JJ, Apelqvist J, Lipsky BA, Bakker K, and on behalf of the International Working Group on the Diabetic Foot. Prevention and management of foot problems in diabetes: a Summary Guidance for Daily Practice 2015, based on the IWGDF Guidance Documents. Diabetes Metab Res Rev 2016; 32: 7-15.
  6. Macfarlane RM and Jeffcoate WJ. Factors contributing to the presentation of diabetic foot ulcers. Diabet Med 1997; 14: 867-70.
  7. Västra Götalandsregionen. Regionalt vårdprogram/riklinjer. Diabetesfoten 2014. https://alfresco.vgregion.se/alfresco/service/vgr/storage/node/content/3132/Diabetesfoten.pdf?a=false&guest=true&native=true. Accessed 2017-01-22.
  8. Nationella Diabetes Registret. Årsrspport 2015. 2016.
  9. Bus SA, Deursen RW, Armstrong DG, Lewis JEA, Caravaggi CF, Cavanagh PR, et al. Footwear and offloading interventions to prevent and heal foot ulcers and reduce plantar pressure in patients with diabetes: a systematic review. Diabetes Metab Res Rev 2016; 32: 99-118.
  10. Bus SA and van Netten JJ. A shift in priority in diabetic foot care and research: 75% of foot ulcers are preventable. Diabetes Metab Res Rev 2016; 32: 195-200.
  11. Dahmen R, Haspels R, Koomen B, and Hoeksma AF. Therapeutic Footwear for the Neuropathic Foot: An algorithm. Diabetes Care 2001; 24: 705-9.
  12. Jannink MJA, Geertzen JHB, Hijmans JM, van Netten JJ, and Postema K. Patients’ expectations and actual use of custom-made orthopaedic shoes. Clin Rehabil 2010; 24: 919-27.
  13. Paton JS, Roberts A, Bruce GK, and Marsden J. Patients’ Experience of therapeutic footwear whilst living at risk of neuropathic diabetic foot ulceration: an interpretative phenomenological analysis (IPA). Journal of Foot and Ankle Research 2014; 7: 16.
  14. Sherrington C and Hylton HB. An evaluation of footwear worn at the time of fall-related hip fracture. Age Ageing 2003; 32: 310-4.
  15. Farndon L, Robinson V, Nicholls E, and Vernon W. If the shoe fits: development of an on-line tool to aid practitioner/patient discussions about ‘healthy footwear’. Journal of Foot and Ankle Research 2016; 9: 17.
  16. Horgan NF, Crehan F, Bartlett E, Keogan F, O’Grady AM, Moore AR, et al. The effects of usual footwear on balance amongst elderly women attending a day hospital. Age Ageing 2009; 38: 62-7.
  17. Koepsell TD, Wolf ME, Buchner DM, Kukull WA, LaCroix AZ, Tencer AF, et al. Footwear Style and Risk of Falls in Older Adults. J Am Geriatr Soc 2004; 52: 1495-501.
  18. Kusumoto A, Suzuki T, Yoshida H, and Kwon J. Intervention Study to Improve Quality of Life and Health Problems of Community-Living Elderly Women in Japan by Shoe Fitting and Custom-Made Insoles. Gerontology 2008; 53: 348-56.
  19. Menant JC, Steele JR, Menz HB, Munro BJ, and Lord SR. Optimizing footwear for older people at risk of falls. J Rehabil Res Dev 2008; 45: 1167-82.
  20. Menant JS, Steele JR, Menz HB, Munro BJ, and Lord SR. Effect of footwear features on balance and stepping in older people. Gerontology 2008; 54.
  21. Sullivan J, Pappas E, Adams R, Crosbie J, and Burns J. Determinants of footwear difficulties in people with plantar heel pain. Journal of Foot and Ankle Research 2015; 8: 40.
  22. Tomassoni D, Traini E, and Amenta F. Gender and age related differences in foot morphology. Maturitas 2014; 79: 421-7.
  23. Park J. Gauging the Emerging Plus-Size Footwear Market An Anthropometric Approach. Clothing and Textiles Research Journal 2013; 31: 3-16.
  24. Hellstrand Tang U, Zügner R, Lisovskaja V, Karlsson J, Hagberg K, and Tranberg R. Comparison of plantar pressure in three types of insole given to patients with diabetes at risk of developing foot ulcers – A two-year, randomized trial. Journal of Clinical & Translational Endocrinology 2014; 1: 121-32.
  25. Hellstrand Tang U. The Diabetic Foot – assessment and assistive devices. 2017.
  26. Hanson L, Sperling L, Gard G, Ipsen S, and Olivares Vergara C. Swedish anthropometrics for product and workplace design. Appl Ergon 2009; 40: 797-806.
  27. Boulton AJ, Armstrong DG, Albert SF, Frykberg RG, Hellman R, Kirkman MS, et al. Comprehensive Foot Examination and Risk Assessment: A report of the Task Force of the Foot Care Interest Group of the American Diabetes Association, with endorsement by the American Association of Clinical Endocrinologists. Diabetes Care 2008; 31: 1679-85.
  28. Rayman G, Vas PR, Baker N, Taylor JCG, Gooday C, Alder AI, et al. The Ipswich Touch Test: a simple and novel method to identify inpatients with diabetes at risk of foot ulceration. Diabetes Care 2011; 34: 1517-8.
  29. Hellstrand Tang U, Zugner R, Lisovskaja V, Karlsson J, Hagberg K, and Tranberg R. Foot deformities, function in the lower extremities, and plantar pressure in patients with diabetes at high risk to develop foot ulcers. Diabet Foot Ankle 2015; 6.
  30. Lewin T, Bergkvist B, Berglund L, Björnfoot L, zu Dohna B, Ekholm C, et al. Kroppsmått hos unga män. Underlag för bestämning av kläders och skyddsutrustnings storlek och konstruktion samt funktionsmått vid olika aktiviteter. 1973.
  31. Lewin T. Kroppsmått hos män och kvinnor. Deskriptiv statistik gällande kvinnor i åldern 20-24, 25-49 och 70 år samt män och kvinnor i 20 års ålder, in D. 1. 3, Deskriptiv statistik gällande kvinnor i åldern 20-24, 25-49 och 70 år samt män och kvinnor i 20 års ålder. 1975.
  32. Lewin T. Kroppsmått hos män och kvinnor. Ordförklaringar, måttdefinitioner, tabell – och diagramindex och appendix in English, in D. 3, Ordförklaringar, måttdefinitioner, tabell- och diagramindex och appendix in English. 1975.
  33. International Working Group on the Diabetic Foot. Summary guidance for the daily practice 2015. 2015. http://iwgdf.org/guidelines/summary-guidance-for-the-daily-practice-2015/. Accessed 2017-01-22.
  34. Rome K, Stewart S, Vandal AC, Gow P, McNair P, and Dalbeth N. The effects of commercially available footwear on foot pain and disability in people with gout: A pilot study. BMC Musculoskelet Disord 2013; 14: 2-9.
  35. Williams A. Footwear assessment and management: understanding shoe construction and materials aids in property fitting patients. 2007, Kane Communications, Inc. p. 165.
  36. Chantelau E and Gede A. Foot dimensions of elderly people with and without diabetes mellitus – a data basis for shoe design. Gerontology 2002; 48: 241-4.
  37. Lewin T and Skrobak-Kaczynski J. Anthropometrical studies on mature Swedish industrial employees. Z Morphol Anthropol 1972; 64: 348-61.
  38. Domjanic J, Seidler H, and Mitteroecker P. A combined morphometric analysis of foot form and its association with sex, stature, and body mass. Am J Phys Anthropol 2015; 157: 582-91.
  39. Saghazadeh M, Kitano N, and Okura T. Gender differences of foot characteristics in older Japanese adults using a 3D foot scanner. Journal of Foot and Ankle Research 2015; 8: 29.
  40. Mickle KJ, Munro BJ, Lord SR, Menz HB, and Steele JR. Can Grandma wear Grandpa’s shoes? Footwear Science 2009; 1 Suppl 1: 5-6.
  41. Lewin T. Anthropometric Studies on Swedish Industrial Workers when Standing and Sitting. Ergonomics 1969; 12: 883-902.
  42. Brolin E, Chalmers University of Technology, Production Development, and Production Systems. Anthropometric diversity and consideration of human capabilities. 2016.
  43. Hultkrantz V. Über die Zunahme der Körpergrösse in Schweden in den Jahren 1840-1926: Norblads bokh. 1927.
  44. Dahlberg G and Lander E. Size and form of the foot in men. Acta Genet Stat Med 1948; 1: 115.
  45. van Netten JJ, Hijmans JM, Jannink MJ, Geertzen JH, and Postema K. Development and reproducibility of a short questionnaire to measure use and usability of custom-made orthopaedic shoes. J Rehabil Med 2009; 41: 913-8.
  46. World Health Organization. Priority Assistive Products List. 2016.
  47. McInnes AD, Hashmi F, Farndon LJ, Church A, Haley M, Sanger DM, et al. Comparison of shoe-length fit between people with and without diabetic peripheral neuropathy: a case-control study. Journal of Foot and Ankle Research 2012; 5: 9.
  48. Burns SL, Leese GP, and McMurdo ME. Older people and ill fitting shoes. Postgrad Med J 2002; 78: 344-6.
  49. Menz HB, Auhl M, Ristevski S, Frescos N, and Munteanu SE. Evaluation of the accuracy of shoe fitting in older people using three-dimensional foot scanning. JOURNAL OF FOOT AND ANKLE RESEARCH 2014; 7: 3.
  50. Department of Prosthetic and Orthotics Sahlgrenska University Hospital. Brukarinformation – skoråd. 2014. https://www2.sahlgrenska.se/sv/SU/Omraden/3/Verksamhetsomraden/Ortopedteknik/Det-gor-ortopedtknik/Brukarinformation/. Accessed 24 Nov 2016.
  51. Barton CJ, Bonanno D, and Menz HB. Development and evaluation of a tool for the assessment of footwear characteristics. Journal of Foot and Ankle Research 2009; 2: 10.
  52. Dahmen R, van der Wilden GJ, Lankhorst GJ, and Boers M. Delphi process yielded consensus on terminology and research agenda for therapeutic footwear for neuropathic foot. J Clin Epidemiol 2008; 61: 819-26.
  53. Pheasant S. Bodyspace: anthropometry, ergonomics and design of work. London: Taylor & Francis. 1996.

Delayed Primary Closure of Diabetic Foot Wounds using the DermaClose™ RC Tissue Expander

by David L. Nielson, DPM1, Stephanie C. Wu, DPM, MSc2, David G. Armstrong, DPM, PhD3

The Foot & Ankle Journal 1(2):3

Closure of large wounds has been a challenge in podiatric surgery, especially after large defects created by ulcer debridement, metatarsal resection and amputation. The DermaClose™ RC tissue expander allows for closure of large defects without the need for traditional complex skin closure, tissue grafting or creation of skin and tissue flaps. Skin anchors made of surgical steel clips are used with a tension controller to allow for gentle skin stretching on the subcutaneous planes of the wound or defect. It also has special application in the closure of chronic wounds. Two case reports are presented to describe this technique.

ISSN: 1941-6806/08/0102-0003
doi: 10.3827/faoj.2008.0102.0003

Mechanically assisted delayed primary closure of large foot wounds following emergency or ablative surgery will result in faster healing and assist in enhanced closure of a large tissue defect. The technique of rapid wound closure is enhanced with the use of the DermaClose™ RC tissue expanding device. The application of the device is simple and provides for a less complex treatment course than secondary wound closure.

Tissue expansion was first employed by placing straight wires (0.045-0.062) though the skin adjacent to the wound. Special ratcheting devices, suture, or 28 gauge wire are used to bring the straight wires closer thus exploiting stress relaxation inherent in skin. [1-4] A variety of companies make several devices to accomplish the same goal today. Mechanically assisted wounds have been shown to close up to 40% quicker than traditional secondary intention healing. [1]

When a wound is created, healing is either by primary closure if enough tissue is available or by secondary intention healing. Many times, in podiatry, large wounds and defects are created after ulcer debridement, metatarsal or bone resection and amputation. Secondary intention wound healing can be facilitated by a variety of modalities including local wound care, negative pressure vacuum therapy, hyperbaric therapy, tissue growth factors and application of bioengineered tissue equivalents. However, secondary intention healing of the defect often take weeks or months adding to the cost of wound and palliative care.

Delayed primary closure can also be challenging, especially in the foot. Many times this will include complex tissue closure, tissue grafts and adjacent tissue flaps to promote full wound closure.

The tissue expansion device now allows for rapid closure. It can also provide cost savings in respect to decreasing the need for prolonged wound care. We present two case reports describing the use of the DermaClose™ tissue expanding device.

Case #1

A 59 year old Caucasian male presents to our clinic with a chronic 3 year wound after a hallux and 2nd digital amputation. The patient has a long history of diabetes mellitus and has undergone kidney transplantation.

Application of the DermaClose™ device was initiated and it required about 3 months to close completely. The patient was taking immunosuppressive medication during this time, which may explain the prolonged closure rate.

The surgical site is thoroughly cleansed before application of the tissue anchors. A suture loop is then placed through the anchors and tension is applied by the device. In this case, a figure-8 suture was used to apply uniform tension perpendicular to the skin edges. (Fig.1)

Figure 1 Case #1 shows the patient post amputation with local dehiscence of the wound edges. Here, the DermaClose Clips are placed around the wound and the wound edges are approximated under tension. The suture is applied in a circular or figure-8 fashion. It is important to also protect the foot with foam from the overlying tension device.

Case #2

A 42 year old African-American male presents to our clinic after stepping on a bottle cap in March 2007. The patient is a poorly controlled diabetic with serum glucose running between 250 and 350 mg/dL. His medications include oral hypoglycemics, injectable Insulin and cholesterol lowering drugs. Unfortunately, he developed infection and underwent incision and drainage of deep space abscess with second partial metatarsal resection and digital amputation.

Prior to delayed closure and use of the DermaClose™ device, the patient underwent a series of wound care treatments, negative pressure wound VAC and application of Graft Jacket. After several months, the amputation site failed to close and a large, granulating defect remained. (Fig. 2)

Figure 2 Case #2 represents a large, chronic post-amputation defect.

In order to promote final closure, the DermaClose™ tissue expanding device was applied. Preparation of the wound consists of surgical debridement of all non-viable tissue. The wound edges are undermined about 2cm from the wound edge. (Fig. 3)

Figure 3 The wound must be surgically debrided of all non-viable tissue prior to application of the device. The device is applied and within 3 days the dorsal defect closed. Here, the anchors are tensioned in a shoe-lace fashion.

During the tension phase, the patient remained in a CAM boot and underwent daily dressing changes. Final closure of the defect was accomplished within just a few days of application. (Fig. 4,5)

Figure 4 Closure of the chronic wound using the DermaClose device.

Figure 5 Plantar view of the closed wound. A separate DermaClose device was applied plantarly.

Application

The device describe, (DermaClose™, Wound Care Technologies, Chanhassen, MN, USA) consist of skin anchors made of 316L surgical stainless steel and placed circumferential to the wound 1-1.5 cm from the wound edge.

The anchors penetrate the skin and into the subcutaneous tissue. Each anchor is held in place with two skin staples. A monofilament, high strength suture is then woven around each anchor.

The suture is then tightened to approximately 1.3kg of force, bringing the wound edges closer together. Once the dynamic tension is reached, additional tightening is not needed.

Patients should be seen every 3-5 days for evaluation of the device and the tissue movement. Care should be noted that the anchors do not envelop or imprint into the skin.

The DermaClose™ tension controller is attached around each skin anchor and the knob of the tension device is rotated until a clutch mechanism provides an audible indication that full tension has been achieved. The device now maintains the proper amount of tension to gently stretch the skin on the subcutaneous planes around the wound until the edges of the wound are brought close enough together for final suturing and closure.

Discussion

In both cases, the wounds are considered chronic, diabetic wounds. The rate of closure varied in case #1 due to immunosuppressive therapy. In general, the DermaClose™ device will provide rapid closure of an otherwise chronic or stagnant wound.

In one of the first studies to evaluate rates of mechanically assisted closure, Armstrong and Lavery reported that closure can be assisted approximately 40% faster than by secondary intension healing alone. [1]

Optimal results were obtained by strict off-loading of the foot during the tension phase of treatment, debridement with meticulous and frequent wound care. Armstrong and Lavery also identified the average healing time of a standard wound was similar to total contact casting.

Both cases represent a cross-sectional example of a small, chronic wound and a larger defect after amputation. Both responded favorably to mechanically induced delayed primary closure.

Conclusion

As one advances from the simple to the complex wound, the theoretical risk for complications increases. Therefore, specialist working in this area should always try to expand his or her armamentarium to assist in wound simplification and closure. Skin stretching devices are among some of these tools. At the Center for Lower Extremity Ambulatory Research (CLEAR), we are experiencing success in utilizing such devices to augment the closure of wounds. Members of CLEAR were amongst the first to evaluate this technique in the lower extremity more than a decade ago. We believe that the quality and breadth of these devices are improving. This can only benefit us as we move forward.

References

1. Armstrong DG, Lavery LA. Mechanically Assisted, Delayed Primary Closure of Diabetic Foot Wounds. JAPMA;88(10):483-488, 1998.
2. Armstrong DG, Sorensen JS, Bushman TB. Exploiting the viscoelastic properties of pedal skin with the sure-closure skin stretching device. JFAS;34(3):247-253, 1995.
3. Armstrong DG, Wunderlich RP, Lavery LA. Reaching closure with skin stretching. Applications in the diabetic foot. Clin Podiatr Med Surg;15(1):109-116, 1998.
4. Hirshowitz B, Lindenbaum E, Har-Shai Y. A skin-stretching device for the harnessing of the viscoelastic properties of skin. Plast Reconst Surg.;92:260-267, 1993.


1,2,3 Scholl’s Center for Lower Extremity Ambulatory Research (CLEAR) at Rosalind Franklin University of Medicine and Science.

© The Foot & Ankle Journal, 2008

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A Unique Method of Plantar Forefoot Ulcer Closure using the Ilizarov Device: Series of 11 Patients with Leprosy

by B. Jagannath Kamath, M.S. (Ortho)1 , Praveen Bhardwaj, M.S., (Ortho)2

The Foot & Ankle Journal 1(1):3

Introduction: Recurrent plantar ulcer is a common and serious problem of anesthetic feet in leprosy. There are many methods described in the literature to deal this problem, but it still remains a great challenge for the treating surgeon. The problem lies not only in attaining the coverage and healing of the ulcer but also to prevent its recurrence. The skin of the forefoot is a specialized one and hence procedures aimed at providing skin from elsewhere will tend to fail. The local flaps described in the literature are effective, but forms a major surgery for this group of patients, requires an expert to perform and are not devoid of complications, which if occur can be disastrous. We are herein describing a technique of closure of these forefoot ulcers, which makes use of the biomechanical properties of the skin and provided closure of these ulcers by slow and sustained stretching of the surrounding natural skin. It thus provides the specialized plantar skin coverage for the ulcers.

Method: We have used this technique in eleven leprosy patients with forefoot ulcers. Four patients had ulcers under the head of first metatarsal, four under the heads of first and second metatarsals, two under the second metatarsal head and one under the heads of fifth metatarsals. Size of the ulcers at its maximum length ranged from 2 – 4 cm.

Results: The technique successfully resulted in healing of all the ulcers without any significant complication. All the ulcers could be closed in ten days and all of them healed well within six weeks.

Conclusion: We found the technique to be very effective. It providing the specialized plantar skin for healing the ulcers is most attractive feature. The technique is simple and free of any major complication. The device used to achieve the closure is very inexpensive, can be easily made and is easy to use.

Key Words: Forefoot ulcers in leprosy; technique of closure; stretching; provides specialized skin cover; simple, inexpensive and effective.

ISSN: 1941-6806/08/0101-0003
doi: 10.3827/faoj.2008.0101.0003

Recurrent plantar ulceration is a frequently seen problem in anesthetic feet of leprosy. The seriousness of these ulcers lie in the fact that it can be difficult to keep the ulcers healed. Management of these chronic ulcers can be very frustrating for the patient and for those involved in their treatment. Ulcers occur in about 30 percent of the patients suffering with leprosy and are most commonly seen at the forefoot. [1] The factors contributing to the onset of these ulcers are impaired sensation, atrophy and fibrosis of muscles of foot and alteration of sympathetic enervation that in turn produces dryness, anhidrosis and hyperkeratosis. As the intrinsic muscles of the foot, which are secondary stabilizers of the metarsophalangeal joints become ineffective, it results in clawing of the toes making the heads of the metatarsals very prominent because of hyperextension of the metacarpophalangeal joints and flexion at the interphalangeal joints. Additionally, the loss of transverse and longitudinal arches of the foot increases the irregular distribution of the weight across the midfoot and metatarsal heads. Ulcers are more common on the plantar forefoot because this is where the greatest forces are concentrated. Ulcers are most common under the first metatarsal head; they also less commonly appear under the second and fifth metatarsal heads. The tissues in this area are highly specialized for the purpose of weight bearing and hence are difficult to reconstruct. [2] Any procedure to cover the defect in this area should ideally provide a stable local tissue. The distant flaps or free flaps described to cover these areas in our view fail because they lack the special architecture for absorbing impact and shear which the plantar skin is subjected to. Quite a number of local flaps are described to get the specialized plantar skin to cover the skin defects. [2-4]These flaps are quite successful, but are technically demanding as the plantar skin allows very little mobilization and if the flaps fail it leaves one in disastrous situation. Some skin stretching techniques have been described in recent past to close skin defects. [5-10]These techniques utilize viscoelastic properties of skin. Biomechanical properties of skin like mechanical creep, recruitment and stress relaxation allows the skin to stretch. We have used this ability of the skin to close the forefoot ulcers in leprosy patients. The technique described is simple, effective and inexpensive. It has given very satisfying results in our experience.

Materials and Methods

Patient selection is very crucial and may dictate the final results. We recommend the procedure for:

1. Ulcers which are not grossly infected
2. The ulcer should not be extending to the bone
3. Size of the ulcer should not exceed 4 cm
4. No diabetes mellitus
5. No peripheral vascular disease

We had eleven cases, which met the criteria mentioned above. Procedure was performed for all these patients; details are described in the table 1.

Case No.

Size of the Ulcer Site of the Ulcer(Under the Head of) Time taken for closure
1. 2 cm First metatarsal 5 days
2. 2.5 cm First metatarsal 5 days
3. 2.5 cm Fifth metatarsal 6 days
4. 3.5 cm First & second metatarsals 8 days
5. 3 cm Second metatarsal 8 days
6. 4 cm First, Second & third metatarsals 10 days
7. 3.5 cm First & second metatarsals 9 days
8. 4 cm First metatarsal 10 days
9. 2.5 cm Second metatarsal 7 days
10. 3.5cm First & second metatarsals 8 days
11. 3cm First metatarsal 8 days

Table 1: Patient details and time taken for ulcer closure.

Thorough debridement and freshening of the edges is mandatory as the highly keratinized scar tissue accompanies the plantar ulcers, which must be excised. We avoid excessive undermining of skin margins as this could risk their viability when a strong stretching force is employed for obtaining extra skin. Also K-wire assembly will be unstable if excessive undermining of the margins is done and may even make insertion of K-wires technically difficult.

Description of Device

The Ilizarov device consists of :

1. Two K-wires of size 1.5 to 1.8 mm. (Figure 1 A)
2. Two specially designed custom-made K-wire holding bolts, which are without any threads and are free to slide over the threaded rods. K-wires are transfixed to these bolts by using either inbuilt or external bolts as shown in the figure no.1. The corners of the bolts are rounded to prevent the sharp edges abrading the skin. (Figure 1 B)
3. Two threaded rods used in Ilizarov’s apparatus in Orthopedic surgery. (Figure 1 C)
4. Eight threaded bolts used in Ilizarov’s apparatus, which can be threaded on to the rod. (Figure 1 D)

Figure 1 Components of the device: A: K-wires; B: K-wire holding bolt; C: threaded rod; D: nuts.

Technique

An example of a forefoot ulcer is shown preoperatively. (Figure 2) The K-wires are passed on the either side of the ulcer at a distance of about one cm from the edge deep enough to engage in the dermis. (Figure 3) It is important to have the K-wires deep enough in the dermis and at equal depth throughout its extent to exert a strong and uniform approximating force. The K-wires are secured onto the K-wire holding bolts. (Figure 1 & 3) Threaded rods are passed into the K-wire holding bolts on both the sides and are secured in place by two threaded bolts on the outer aspect of each K-wire holding bolt. (Figure 3) These threaded bolts will thus approximate the K-wire holding bolts and hence the K-wires as they are tightened.

Figure 2 Preoperative photograph of a patient showing the ulcer present under the heads of metatarsals extending from base of first metatarsal to that of the third metatarsal.

Figure 3 Photograph taken after initial approximation of the wound as was easily possible in the early postoperative days.

We start approximating the wound on the first postoperative day. Each single turn of the threaded bolt causes the K-wires on either side to approximate the wound by 1mm on both sides and causing 2mm decrease in the wound size.

The speed of approximation depends of the skin condition, which is vigilantly monitored. Skin pallor, tautness of skin and shininess and excessive pain are the indicators of temporary stoppage of approximation process. Generally in the beginning we are able to approximate about 5-6 mm and gradually decrease it as the time passes by. In all the cases we have been able to achieve complete closure in 10 days or less. We have experienced that it is possible to achieve a greater degree of closure in medio-lateral direction than the antero-posterior direction. After approximation is achieved the skin edges are sutured and the fixator is maintained for another week. (Figure 4) The patient is kept non-weight bearing for another two weeks. Patients are then advised regarding foot care and hygiene and are asked to avoid static standing for more than 10 minutes at a time. Prevention of recurrence is very crucial. Secondary procedures like metatarsal osteotomy may be done if required to prevent recurrence once the ulcer is closed. (Figure 5)

Figure 4 Photograph after the complete approximation was achieved. At this point the edges are sutured together with a strong non-absorbable material.

Figure 5 Photograph of the same patient showing the ulcer completely closed.

Discussion

Treatment of ulcers in leprosy remains a challenge to the treating surgeon. The various options available are casts, modified foot wears, local flaps and distant flaps.

The non-operative methods are useful only in cases where the size of the ulcer is small and thus for larger ulcers surgery is the only option. The distant flaps fail to provide the specialized plantar skin and hence are likely to fail. The various local flaps described in the literature are quite handy but form a major surgical procedure requiring an expert to perform them and have grave consequence if they fail. The application and principle of gaining tissue by recruitment using force is not new and has been successfully applied to wound coverage problem for years. [5-10] Skin stretching results in significant histo-morphological changes in collagen fibers of the dermis and results in their rapid realigning in response to the stretching force and become aligned in the direction of the stretching force, perpendicular to the wound margin. [11]

Although the technique of tissue expansion was first reported by Newman as early as 1957, [12] it became more popular only after Randovan’s [13] description in 1982. In their experimental and clinical study Liang et al introduced the technique of pre-suturing. [8]

They described the properties of skin, which contribute to its expansion and can be used to close the skin defect. These include: inherent expansion, mechanical creep and biological creep. Inherent extensibility is defined as the excess skin that allows primary excision and closure. Mechanical creep is a biomechanical property of the skin, which allows it to gradually stretch beyond its limits; this is because of straightening of the normally randomly aligned collagen fibers. Biological creep is the property of skin to increase the tissue by mitotic activity, which has been demonstrated to occur within 24 to 48 hours in response to persistent expansion pressure. [14]

Tissue stretching procedures have been widely used, but its use for the sole of the foot has been infrequently reported. This is probably because of the thick plantar skin. Malaviya has described a technique of closure of simple heel ulcers by skin stretching. [15] This is an intraoperative technique in which two needles are places on either side of the ulcer and these needles are than approximated by passing sutures around these needles. This technique may be handy in case of small and superficial wounds only. The device designed by the authors has the strength required to approximate the thick plantar skin and has proved effective in closing ulcers as big as 4 cm. The thicker K-wires, which are passed in deeper dermis and are at equal depth throughout the length, provide a strong grip on the skin required for approximating the thick plantar skin. The device provides control on all the four corners of the wound by virtue of the K-wires. Each corner of the wound can be individually and independently subjected to skin stretching. This differential stretching is a very special feature of our device, which is not possible with any device described, even the patented devices marketed. If it is observed that the skin is becoming tight at any one place, the stretching can be stopped only at that place with continuing stretching to other areas. The compressing rods are on either side of the ulcer; contrary to many marketed stretching devices, which have the compressing rod transversing across the wound and allows for easy care of the ulcer.

The authors device initially uses the mechanical creep to bring about the coverage and probably after two days also induces biological creep accounting for the good results achieved in this report. A patented device-like “sure closure” costs more than 700 dollars per box, but our device will not cost more than a few dollars and can be easily made.

In conclusion, a rather simple solution to overcome otherwise complex situations of skin shortage has been described. We have found that addition of this technique to our armamentarium has effectively increased our options in closure of problematic forefoot plantar ulcers in leprosy.

References

1. Liwen D, Futian Li, Zaiming W, Juan J, Guocheng Z, Jinhu P, Jugen Z, Yongliang Y. Technique for covering soft tissue defects resulting from plantar ulcers in leprosy: Part I- General consideration and summary of results. Indian J Lepr, 1999; 71(3); 285-309.
2. Colen LB, Replogle SL, Mathes SJ. The V-Y flap for reconstruction of forefoot. Plastic Reconstr Surg, 1988; 81(2); 220-228.
3. Lennox WN. Plastic surgery of the anesthetic foot of leprosy. Lepr Rev, 1965; 36(3); 109-117.
4. Giraldo F, De Haro F, Ferrer A. Opposed transverse extended V-Y plantar flaps for reconstruction of neuropathic metatarsal head ulcers. Plastic Reconstr Surg, 2001; 108(4); 1019-1024.
5. Hirshowitz B, Lindenbaum E, Har-Shai Y. A skin-stretching device for the harnessing of the viscoelastic properties of skin. Plastic Reconstr Surg, 1993; 92(2); 260-269.
6. Stahl S, Har-Shai Y, Hirshowitz B. Closure of wound in the extremity using a skin stretching device. J Hand Surgery, 1996; 21B(4); 534-537.
7. Browne T. Closing a wide wound by using two stout spinal needles and three Allis forceps. Plastic Reconstr Surg, 1998; 101(4); 1159-1161.
8. Liang MD, Briggs P, Heckler FR, Futrell W. Presuturing- A new technique for closing large skin defects: Clinical and Experimental study. Plastic Reconstr Surg, 1988; 81(5); 694-703.
9. Concannon MJ, Puckett CL. Wound coverage using modified tissue expansion. Plastic Reconstr Surg, 1998; 102(2); 377-384.
10. Abenavoli FM. A simple tissue extensor. Plastic Reconstr Surg, 2002; 109(5); 1763-1764.
11. Melis P, Noorlander ML, van der Horst CMAM, van Noorden CJF. Rapid alignment of collagen fibers in the dermis of undermined and not undermined skin stretching with a skin-stretching device. Plastic Reconstr Surg, 2002; 109(2); 674-680.
12. Neumann CG. The expansion of an area of skin by progressive distention of a subcutaneous balloon. Plastic Reconstr Surg, 1957; 19; 124-128.
13. Radovan C. Breast reconstruction after mastectomy using the temporary expander. Plastic Reconstr Surg, 1982; 69; 185-202.
14. Lew D, Fuseler JW. The effect of stepwise expansion on the mitotic activity and vascularity of subdermal tissue and induced capsule in the rat .J Oral MaxilloFac. Surg, 1991; 49; 848-853.
15. Malaviya GN. Closure of simple heel ulcers by skin stretching. Indian J Lepr, 2005; 77(3): 53-63.


Address correspondence to: Dr. B. Jagannath Kamath. Jyothi Mansion, Opposite Prabhat Theatre, K. S. Rao Road, Mangalore, India. Pin- 575001. Phone: 91-0824-2440233; Mobile: 91-9845235747
E-mail: bjkamath@satyam.net.in 

1Associate Professor of Orthopaedics, Kasturba Medical College, Mangalore, Karnataka, India.

2Assistant Professor of Orthopaedics, Kasturba Medical College, Mangalore, Karnataka, India.
E-MAIL: drpb12@yahoo.co.in

© The Foot & Ankle Journal , 2008

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