Tag Archives: heel pain

Post-surgical plantar fasciitis

by Priya P. Sundararajan , DPM¹pdflrg

The Foot and Ankle Online Journal 7 (2): 4

Current evidence suggest that plantar fasciitis is multi-factorial in etiology. The following report introduces an extended post-surgical nonweightbearing period (6-10 weeks) as a previously unknown cause of plantar fasciitis. Through a univariate statistical analysis, the present study compares the presence of heel pain in twenty patients who remained nonweightbearing for 2-6 weeks (group 1) and twenty patients who remained nonweightbearing for 6-10 weeks in the post-surgical period (group 2). Results indicate a statistically significant correlation (p<0.05) between patients who endured an extended postoperative nonweightbearing period (group 2) and the presence of plantar fascial symptoms in the immediate weightbearing period. Findings of the present study suggest that a stretching regimen should be initiated prior to ambulation for patients remaining nonweightbearing greater than six weeks post-surgery.

Key Words: Plantar fasciitis, postoperative, nonweightbearing, heel pain, surgery, fascia

ISSN 1941-6806
doi: 10.3827/faoj.2014.0702.0004


Address correspondence to: Priya Sundarararjan DPM,
Wilmington Veterans Affairs Hospital, 1601 Kirkwood Highway, Wilmington, DE 19805

¹ Director of Podiatric Surgical Services, Wilmington Veterans Hospital 302-994-2511 Email: Priya.Sundararajan@va.gov


Plantar fasciitis is one of the most common pedal pathologies requisitioning medical evaluation and treatment, which translates to over one million outpatient visits annually in the United States [1]. Though the pain associated with plantar fasciitis can be debilitating, the syndrome is characterized as self-limiting since approximately 90% of symptomatic patients find relief through conservative measures [2,3]. Plantar fasciitis is the result of multi-factorial etiologies from increased body mass index to ankle equinus [1,4]. The following retrospective analysis introduces the extended post-surgical nonweightbearing period as a previously unknown cause of plantar fasciitis.

Methods

A retrospective review of forty patients who underwent surgery between August 2010 and August 2011 was conducted. These patients remained nonweightbearing between 2 and 10 weeks in the postoperative period. Twenty patients who were completely offloaded between 2 and 6 weeks post surgery were consecutively enrolled in the study as group 1. Similarly, twenty patients who remained completely nonweightbearing between 6 and 10 weeks after surgery were consecutively enlisted as group 2. The six-week mark was considered the divide as most reconstructive surgeries involve offloading for more than 6 weeks. Additionally, all patients remained nonweightbearing between 2 and 10 weeks; thus 6 weeks is the mean week. Exclusion criteria included any prior complaint or treatment of plantar heel pain or any surgery involving the plantar fascia. Patients who bore weight in the heel or forefoot without a two-week nonweightbearing period were also excluded from the study.

All patients were questioned as to the areas of discomfort in the beginning two weeks of the post-surgical weightbearing (WB) period. Specifically, each patient was questioned as to the presence or absence of heel pain. The heel was anatomically defined as the area underlying the calcaneal tuberosity. The presence of postoperative heel pain during the initial weightbearing period was recorded and statistically evaluated with a univariate analysis. If the patient related to having heel pain when first bearing weight, they were instructed to perform at least 15 minutes of calf stretching exercises daily. Patients were monitored until complete resolution of symptoms.

Results

Twenty patients in each group yielded usable results. A description of groups 1 and 2 are depicted in Tables 1 and 2, respectively. A statistically significant difference (p=0.0002) in the presence of heel pain in the early weightbearing period was found between patients who remained nonweightbearing between 2 and 6 weeks (group 1) and those who remained nonweightbearing between 6 and 10 weeks (group 2). Noting that the presence and resolution of symptoms are “yes” and “no” questions, the mean was calculated by assigning “yes” to 1 and “no” to 0. In group 1, 15% of patients reported heel pain during the first two weeks of bearing weight on the operated limb (Table 1). Of these patients, 100% reported total resolution of symptoms within the first six weeks of the weightbearing period with conservative calf stretching exercises. In group 2, 70% of patients reported heel pain during the first two weeks of bearing weight on the operated limb (Table 2). All patients who reported heel pain in both groups related complete relief of symptoms to the heel of the operated extremity within six weeks using conservative modalities, primarily through regimented stretching exercises. However, one patient in group 2 (patient 15) who reported significant relief without total resolution of symptoms was additionally fitted with custom-molded orthotics. With a stretching exercise protocol and orthoses, the patient found complete resolution within 6 weeks of bearing weight.

Discussion

Plantar fasciitis is a complex pathology involving the ligament-bone interface at the inferior aspect of the calcaneal tuberosity [3]. As a primary supporter of the plantar arch, the plantar fascia minimizes transverse plane motion between the calcaneus and metatarsals [3]. Vertical forces from the body travel down the body and exert pressure flattening the medial longitudinal arch [5]. Subjected to significant traction as weight is transferred from the rearfoot to the forefoot, the plantar fascia accommodates the transfer with minimal disruption to the plantar arch [6]. Biomechanical studies simulating total fascial release demonstrate extensive arch deformation in stance and over 200% increase in stresses to the long plantar ligament [7]. Rapid fascial elongation occurs before midstance, hence patients with plantar fasciitis present with sharp pains between heel strike and midstance [6]. Furthermore, research has shown that with 90N of force, the plantar fascia will stretch 4% with the failure point being the clamps [8]. Such research confirms the integrity of the plantar fascia and indicates the majority of the pathology occurs at the fascial-calcaneal interface.

Factors

As demonstrated in the present study, post-static dyskinesia is a hallmark of plantar fasciitis [3]. Frequently, patients give a history of sharp pain with insidious onset when first bearing weight after recumbent periods. Typically patients complain of maximal pain with initial ambulation in the morning. Plantar fasciitis is caused by bearing weight after a state of relative inactivity [9]. In the static nonweightbearing state, the plantar fascia is void of tension and thus rests in a contracted state [9]. In the immediate weightbearing period following recumbency, the plantar fascia undergoes a rapid elongation up to 4%, thus the patient experiences sharp, stabbing pains with initial weightbearing [6,8]. When extrapolating the recumbent state from a few hours to several weeks, the fascia is in a state completely void of weightbearing tension. Consequently, patients applying pressure to the heel of a limb which has not carried weight for a significant period of time will likely exhibit symptoms of plantar fasciitis as demonstrated by the current study.

fasciitis1

Table 1 Heel pain in patients remaining nonweightbearing between 2 and 6 weeks (Group 1).

Previous research has demonstrated an increased incidence of plantar fasciitis in individuals experiencing weight gain in the cases of pregnancy or obesity [10]. The mechanical overload causes excessive strain to the arch supporting capacity of the plantar fascia resulting in microtears in the plantar fascia [3]. Histopathological analysis of fascial specimens in chronically symptomatic patients reveal fibroblastic proliferation and granulomatous tissue signifying the cyclic degeneration and limited inflammatory response sustained at the fascial origin [11]. MRI and ultrasound reviews indicate that the dorsal-plantar thickness of plantar fascia in symptomatic patients can increase to 10 mm in thickness, whereas normal plantar fascia is approximately 3 mm [12,13,14]. Though patients in the present study did not exhibit chronicity in their fascial symptoms, the weight gain generally associated with the post-surgical nonweightbearing period may have exacerbated plantar fascial symptoms demonstrated in the early ambulatory stage.

In addition to an elevated body mass index, studies have reported patients with limited ankle flexion to have an increased incidence of plantar fasciitis [10]. Patients with ankle equinus are unable to fully utilize the entire length of the plantar fascia since the heel is bearing less than its proportional weight [10]. Similarly, in the nonweightbearing state the ankle usually rests in some degree of plantarflexion, thus allowing the plantar fascia to contract [9]. When patients begin ambulation after an extended nonweightbearing period, they may experience an incapacitating plantar fascial pain as demonstrated by the current study. All patients exhibited acute manifestations of fasciitis; hence, time to resolution of symptoms was abbreviated in the present study compared to clinical patients demonstrating chronic symptoms. With persistence of plantar fasciitis, pain becomes recalcitrant throughout the day and night [15]. Research correlates the presence of rest pain and night pain with a high failure rate of conservative treatment and serves as an indication for surgical intervention [15].

fasciitis2

Table 2 Heel pain in patients remaining nonweightbearing between 6 and 10 weeks (Group 2).

Treatment

Preliminary treatment protocols for acute plantar fasciitis involve regimented stretching exercises. Plantar fasciitis has earned the reputation of being a self-limiting condition since most patients achieve resolution of symptoms with conservative treatment alone as supported by the present study [2,16]. Stretching protocols often focus on either the posterior compartment of the leg or the plantar fascia itself. Prospective studies demonstrate that regular stretching of either focal point decreases overall pain and pain experienced with initial ambulation [17]. Fascial stretching exercises involve dorsiflexion of the hallux and lesser digits which passively tensions the plantar fascia [3]. Calf stretching exercises work by actively tensing the gastrosoleal complex as well as the plantar fascia [4]. Over 80% of patients with plantar fasciitis demonstrate a concomitant equinus; consequently, equinus is characterized as an etiologic factor of plantar fasciitis [4]. Research has shown that calf stretching exercises result in increased ankle dorsiflexion which directly increases fascial stretch [18,19]. The effectiveness of calf stretching exercises alone is evident in the present study. Furthermore, one case in the current study supported the effectiveness of combining calf stretching exercises with custom molded arch supports as demonstrated by previous research [20].

Conclusion

To the author’s knowledge, the following statistical analysis is the first to introduce an extended post-surgical nonweightbearing period (6-10 weeks) as an etiology of plantar fasciitis. The data presented suggests a statistically significant correlation between the length of postoperative nonweightbearing period and the presence of plantar fascial symptoms in the early ambulatory stage. The lack of fascial tension in the recumbent state, post-surgical weight gain, and ankle plantarflexion may be factors which intensify plantar fasciitis. These compounding factors deserve further research to clarify their significance in post-surgical plantar fasciitis. The clinical implication of the present research suggests that practitioners should implement stretching protocols prior to initiating ambulation. Accordingly, surgeons may facilitate a smoother transition to return to activity by preventatively countering plantar fascial symptoms. The current study is limited in its capacity to determine the full nature of post-surgical plantar fasciitis by its inability to accurately access patient compliance to the nonweightbearing regimen and patient adherence to the prescribed stretching program. By correlating post-surgical plantar fasciitis in terms of ranges, the current study obviates the need to determine exact patient compliance to the nonweightbearing timeline. Moreover, the minute p-value (p=0.0002) indicates a strong correlation between a nonweightbearing postoperative period greater than six weeks and plantar fascial symptoms. In conclusion, the current study presents a new etiology and clinical scenario associated with plantar fasciitis which surgeons and practitioners may preventatively treat by implementing stretching protocols prior to ambulation for patients with a lengthened post-surgical nonweightbearing period.

References

  1. Riddle DL, Schappert SM. Volume of ambulatory care visits and patterns of care for patients diagnosed with plantar fasciitis: a national study of medical doctors. Foot Ankle Int. 2004;25 (5): 303-10. – Pubmed
  2. Wolgin M, Cook C, Graham C et-al. Conservative treatment of plantar heel pain: long-term follow-up. Foot Ankle Int. 1994;15 (3): 97-102. – Pubmed
  3. League AC. Current concepts review: plantar fasciitis. Foot Ankle Int. 2008;29 (3): 358-66. – Pubmed
  4. Patel A, Digiovanni B. Association between plantar fasciitis and isolated contracture of the gastrocnemius. Foot Ankle Int. 2011;32 (1): 5-8.  – Pubmed
  5. Bolgla LA, Malone TR. Plantar fasciitis and the windlass mechanism: a biomechanical link to clinical practice. J Athl Train. 2004;39 (1): 77-82.  – Pubmed
  6. Gefen A. The in vivo elastic properties of the plantar fascia during the contact phase of walking. Foot Ankle Int. 2003;24 (3): 238-44. – Pubmed
  7. Gefen A. Stress analysis of the standing foot following surgical plantar fascia release. J Biomech. 2002;35 (5): 629-37. – Pubmed
  8. Wright DG, Rennels DC. A study of the elastic properties of plantar fascia. J Bone Joint Surg Am. 1964;46 : 482-92.  – Pubmed
  9. Cole C, Seto C, Gazewood J. Plantar fasciitis: evidence-based review of diagnosis and therapy. Am Fam Physician. 2005;72 (11): 2237-42.  – Pubmed
  10. Riddle DL, Pulisic M, Pidcoe P et-al. Risk factors for Plantar fasciitis: a matched case-control study. J Bone Joint Surg Am. 2003;85-A (5): 872-7.  – Pubmed
  11. Singh D, Angel J, Bentley G et-al. Fortnightly review. Plantar fasciitis. BMJ. 1997;315 (7101): 172-5.  – Pubmed
  12. Berkowitz JF, Kier R, Rudicel S. Plantar fasciitis: MR imaging. Radiology. 1991;179 (3): 665-7. – Pubmed
  13. Grasel RP, Schweitzer ME, Kovalovich AM et-al. MR imaging of plantar fasciitis: edema, tears, and occult marrow abnormalities correlated with outcome. AJR Am J Roentgenol. 1999;173 (3): 699-701. – Pubmed
  14. Kier R. Magnetic resonance imaging of plantar fasciitis and other causes of heel pain. Magn Reson Imaging Clin N Am. 1994;2 (1): 97-107. – Pubmed
  15. Haake M, Buch M, Schoellner C et-al. Extracorporeal shock wave therapy for plantar fasciitis: randomised controlled multicentre trial. BMJ. 2003;327 (7406): 75. – Pubmed
  16. Davis PF, Severud E, Baxter DE. Painful heel syndrome: results of nonoperative treatment. Foot Ankle Int. 1994;15 (10): 531-5. – Pubmed
  17. Digiovanni BF, Nawoczenski DA, Lintal ME et-al. Tissue-specific plantar fascia-stretching exercise enhances outcomes in patients with chronic heel pain. A prospective, randomized study. J Bone Joint Surg Am. 2003;85-A (7): 1270-7.  – Pubmed
  18. Flanigan RM, Nawoczenski DA, Chen L et-al. The influence of foot position on stretching of the plantar fascia. Foot Ankle Int. 2007;28 (7): 815-22.  – Pubmed
  19. Radford JA, Burns J, Buchbinder R et-al. Does stretching increase ankle dorsiflexion range of motion? A systematic review. Br J Sports Med. 2006;40 (10): 870-5. – Pubmed
  20. Pfeffer G, Bacchetti P, Deland J et-al. Comparison of custom and prefabricated orthoses in the initial treatment of proximal plantar fasciitis. Foot Ankle Int. 1999;20 (4): 214-21. – Pubmed

Evaluation of the results of autologous blood injection in the treatment of refractory heel pain

By Muzamil Ahmad Baba1, B. A Mir2, M. A Halwai3, Arshad Bashir2, Shakir Rashid1, Omar Khursheed1, Qazi Manaan1pdflrg

The Foot and Ankle Online Journal 6 (10): 2

Background: Plantar heel pain is one of the most common problems of the foot treated by health care professionals. As the precise etiological diagnosis of a painful heel still remains unknown, this entity remains enigmatic and frustrating to both the physician and the patient. The present study was done to assess the efficacy of autologous blood injection in the treatment of refractory heel pain.
Methodology: Fifty patients (average age of 46.7 years), 18 (36%) males and 32 (64%) females with refractory heel pain of more than 6 months duration underwent autologous blood injection. Patients were clinically evaluated and reviewed with visual analogue scale (VAS) pain scores pre-procedure and post procedure at 6 weeks followed by a final follow up at 6 months.
Results: Our study showed a significant reduction in VAS scores which reduced from a mean score of 8 (range 6-10) to a mean score of 4 (range 2-9) at 6 weeks and 2(range 0-9) at 6 months.
Conclusion: Autologous blood injection can be used as a treatment modality in patients with heel pain.

Key words: Autologous blood, heel pain, plantar fasciitis

Accepted: September, 2013
Published: October, 2013

ISSN 1941-6806
doi: 10.3827/faoj.2013.0610.002

Address correspondence to: Muzamil Ahmad Baba (MS), Post graduate department of orthopaedics Govt. Hospital for Bone and Joint Surgery Barzullah, Srinagar Kashmir, 190005. Mobile 9086181281. Email: muzamilbaba79@yahoo.com

1Orthopaedic Resident, Post graduate department of Orthopaedics Govt. Hospital for Bone and joint surgery Srinagar Kashmir.
2Associate professor, Govt. Hospital for Bone and joint surgery Srinagar Kashmir.
3Professor and Head, , Govt. Hospital for Bone and joint surgery Srinagar Kashmir.


In 1922, Stiell stated that painful heel appears to be a condition which is seldom efficiently treated, for the simple reason that the causation is not exactly diagnosed.[1]

It was 40 years later that Lapidus and Guidotti, in their article “Painful heel”, stated that the name painful heel is used deliberately in preference to any other more precise etiological diagnosis, since the cause of this definitive clinical entity still remains unknown. This entity of painful heel still remains enigmatic and often frustrating to both the doctor and the patient.[2]

The exact cause of painful heel is uncertain. It is known that the degenerative changes with increasing age are the most constant findings in the elastic adipose tissue of the heel pad.[3- 5]

Aging also brings about a gradual reduction in collagen and water content as well as in elastic fibrous tissue. Woolnough called the entity “tennis heel”, and postulated that repeated traction with aging and repeated trauma, produces microscopic tears and cystic degeneration in the origin of the plantar fascia and the flexor digitorum brevis immediately beneath the plantar fascia.[4] Other theories include the windlass mechanism and the neurogenic causes.[5]

As the etiology of plantar fasciitis is unclear, diagnosis is usually based on clinical signs including: plantar heel pain when weight-bearing after a period of rest, pain that eases with initial activity, but then increases with further use as the day progresses, and pain on palpation.[6] The various treatment options for this condition includes rest, massage, stretching, ultrasound, extra-corporeal shock wave therapy, cold/ heat therapy, orthotics, anti-inflammatory medications, injection of corticosteroids and surgery in refractory cases.[7, 8]

The findings of existing clinical trials provide some support for the use of corticosteroid injection in the short term management of plantar fasciitis.9 However; a recent systematic review concluded that the effectiveness of this treatment has not been sufficiently established, indicating that further research is required. Local steroid injections can provide good short-term relief of symptoms, but are associated with complications such as the rupture of plantar fascia and fat pad atrophy.[10, 11]

Treatment with autologous blood injections acts by providing various cellular and humoral mediators like growth factors which result in healing and relief of pain without any risk of plantar fascia rupture and fat pad atrophy.[12] As autologous blood injection in heel pain is the least studied, we carried out this study to find out the efficacy of this form of treatment in cases of refractory heel pain in which other treatment modalities had failed thus acting as their own controls.

Material and Methods

In our study, 50 patients with refractory heel pain were included following informed consent and institutional review board approval. Inclusion criteria included all patients with unilateral symptoms of at least 6 months with failure to conservative treatment including stretching, orthotics, local steroid injections or other conservative treatment modalities. Exclusion criteria included patients with symptoms of less than 6 months duration, current skin or soft tissue infection at the site, systemic inflammatory diseases, patients with bilateral involvement and patients who had received a steroid injection or other intervention within 3 months period.

A record of the patient’s pain using a visual analogue scale (VAS) was obtained prior to the procedure using a range of 0 to 10, with 0 representing no pain and 10 the worst pain ever experienced. Two millimeters of autologous blood was drawn from the antecubital fossa of the patient. The heel along with the foot was prepared and draped and 2 ml of 2% lignocaine was infiltrated along the surface followed by insertion of a 23 G needle at the most tender point and the blood was slowly injected into the site of maximum pain. Patients were advised to follow up at 2 and 6 weeks and a final follow up at 6 months. All injections were performed by two senior orthopaedic surgeons. The VAS was recorded prior to the procedure and recorded again at 6 weeks and 6 months post injection follow-up.

Results

Between May 2010 to June 2012, 54 patients were included in the study having met the inclusion criteria. Out of these, 4 patients were lost to follow-up while 50 patients completed the study and were followed for a period of 6 months following the injection. There were 32 (64%) females and 18 (32%) males in our study. The age of the patients ranged from 26 to 63 with an average age of 46.7 years. The mean period of symptoms was 11 months (range 6 to 28 months).

Gender Side Age (years) Duration of symptoms (months)
Male= 18 (36%) Right= 17 (34%) <30= 2 (4%) 6 – 12= 11 (22%)
Female = 32 (64%) Left= 33 (66%) 30 – 50= 39 (78%) 12 – 18= 33 (66%)
>50= 9 (18%) 18 – 36= 6 ( 12%)

Table 1: Distribution of patients on basis of gender, age, laterality and duration of symptoms.

Visual analogue scale (VAS) score NO. OF PATIENTS (Total=50)
Pre procedure At 6 weeks At 6 months
0 – 3 0 12 (24%) 41 (82%)
4 -7 11 (22%) 33 (66%) 4 (8%)
8 – 10 39 (78%) 5 (10%) 5 (10%)

Table 2: The VAS scores prior to the treatment and at 6 weeks and final follow up at 6 months.

The left side was more frequently involved 33 (66%) as compared to 17 (34%) on right side. (Table 1)

In our patients, the median VAS pain score at pre procedure was 8 (range 6-10) which decreased to a mean of 4 (range 2- 9) at 6 weeks and a mean score of 2 (range 0 – 8) at 6 months. Statistical analysis revealed a significant decrease in the score (p<.001). (Table 2)

Out of 50 cases, 4 (8%) patients showed an initial improvement but had a recurrence of symptoms with minimal or no change in VAS scores at 6 months. Five (10%) of the cases failed to respond to the treatment. Statistically significant improvement was seen in rest of the 41 (82%) cases both at 6 weeks and 6 months follow-up. Among complications 11 (22%) patients reported an initial temporary increase in pain which resolved within 2 – 3 days, with 3 (6%) patients requiring shot term use of narcotics. There was no infection, neurovascular damage, plantar fascia rupture in our study group.

Discussion

Plantar heel pain is one of the most common foot complaints presenting to a healthcare professional.[13] Reliable incidence data is lacking in many countries including our country. In USA, its incidence has been estimated to be around 10% and accounts for over one million medical visits every year.[13, 14]

A clear etiology still remains unknown, but plantar fasciitis is reported as the most common cause and the terms are frequently used interchangeably in the literature. Conservative treatment is used for this condition in majority of the cases and surgery being used in cases with failed conservative treatment. Surgery carries the risk of nerve injury, infection, rupture of the plantar fascia, and failure to improve the pain.[15] Corticosteroid injections have been shown to be effective in improving symptoms however it has been associated with various complications such as rupture of plantar fascia, calcaneal osteomyelitis and fat pad atrophy.[10, 11]

No such complication occurred in our series. In our study 41 (82%) of the patients had an excellent outcome with only 5 (10%) patients showing no relief and 4 (8%) cases showing a recurrence at final follow up.

In a study of autologous blood injections in plantar fasciitis by Frontera, 80% cases responded to the treatment.[12] Other treatment options like extra-corporeal shock wave therapy (ESWT) have been tried recently, however there is contradictory evidence and recommendations for the efficacy of extracorporeal shockwave therapy (ESWT), as a treatment modality for plantar fasciitis.[16]

The introduction of autologous blood into an area of inflammation will initiate the inflammatory cascade and promote healing in an otherwise degenerative process such as tendinosis or fasciosis. Barrett, et al.[17] also reported on the use of injectable Autologous Platelet Concentrate (APC+) for the treatment of plantar fasciosis. The hypothesis was that by injecting APC+ into recalcitrant, symptomatic plantar fascia was thought to cause a reparative effect leading to a resolution of symptoms. He termed this technique plantar fasciorraphy. His study included 9 patients who enrolled in the study. Of the 9 patients enrolled, 6 patients reported complete relief of symptoms post injection. At one year post study, 7 (77.8%) of the 9 patients had complete relief of symptoms.

Conclusion

Autologous blood injection appears to be a viable and effective treatment in chronic heel pain. It appears to be safe, cost effective and effective form of treatment even in cases who do not respond to other treatment modalities.

References

1. Stiell WF. Painful heel. Practitioner 1922 108: 345.
2. Lapidus PW, Guidotti FP. Painful heel: report of 323 patients with 364 painful heels. Clin Orthop 1965 39: 178-186. [PubMed]
3. Canale TS, Beaty HJ, Murphy AG. Disorder of tendons and fascia. Campbell’s Orthopaedics. 11th ed. Philadelphia USA; 2008. P. 4815-4818.
4. Woolnough J. Tennis heel. Med J Aus 1954 2: 857-861. [PubMed]
5.  Lemont H, Ammirati K, Usen N. Plantar fasciitis: a degenerative process (fasciosis) without inflammation. JAPMA 2003 93: 234-237. [PubMed]
6.  Schepsis A, Leach R, Gorzyca J. Plantar fasciitis: etiology, treatment, surgical results, and review of the literature. Clin Orthop1991 266: 185-196. [PubMed]
7.  Crawford F, Thomson C. Interventions for treating plantar heel pain. Cochrane Database Syst Rev 2003 3: CD 000416. [PubMed]
8.  Landorf K, Menz H. Plantar heel pain and fasciitis. Clin Evid 2008 2: 1111. [PubMed]
9.  Tatli ZY, Kapasi S. The real risks of steroid injection for plantar fasciitis with a review of conservative therapies. Curr Rev Musculosketel Med 2009 2: 3-9. [PubMed]
10.  Sellman JR. Plantar fascia rupture associated with corticosteroid injection. Foot Ankle Int 1994 15: 376-81. [PubMed]
11.  Acevedo JI, Beskin JL. Complications of plantar fascia rupture associated with corticosteroid injection. Foot Ankle Int 1998 19: 91-97. [PubMed]
12.  Frontera RW, Silver KJ, Rizzo DT. Autologus blood injection in plantar fascitis. Essential Phy Med Rehab 2008 472-473.
13.  Dunn JE, Link CL, Felson DT, Crincoli MG, Keysor JJ, McKinlay JB. Prevalence of foot and ankle conditions in a multiethnic community sample of older adults. Am J Epidemiol 2004 159: 491-498. [PubMed]
14.   Riddle DL, Schappert SM. Volume of ambulatory care visits and patterns of care for patients diagnosed with plantar fasciitis: a national study of medical doctors. Foot Ankle Int 2004 25:303-310. [PubMed]
15.  Kauffman J.  (2006-09-21). Plantar Fascitis. MedlinePlus Medical Encyclopedia. National Institutes of Health.
16.  Rompe JD, Furia J, Weil L, Maffulli N. Shock wave therapy for chronic plantar fasciopathy. Br  Med Bull 2007 81-82: 183-208. [PubMed]
17.  Barrett S, Erredge S. Growth factors for chronic plantar fasciitis. Podiatry Today 2004 17: 37-42.