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A Guide To Conservative Care For Recalcitrant Plantar Heel Pain
Given the common nature of heel pain and the fact that reportedly more than one-third of those with heel pain have had it for two years or more, this author discusses practical pointers and the current evidence on conservative treatment options.
Plantar fasciitis is the most common cause of chronic pain beneath the heel in adults and accounts for over 1 million patient visits per year.1 In 2007, the cost of plantar fasciitis treatment to third-party payers ranged from $192 to $376 million.2
The American Podiatric Medical Association recently conducted a national study investigating how frequently Americans suffer from foot pain, specifically heel pain.3 There were 1,082 survey respondents, representing a cross-sectional sample of the U.S. population. Of those respondents, 76 percent had experienced at least one episode of foot pain within the last year and 40 percent of respondents reported heel pain specifically.3
While 15 percent of Americans who currently experience heel pain have endured the condition for between one and two years, more than one-third (35 percent) of them have had it for two years or more.1 Accordingly, let us explore the current options for treating recalcitrant plantar fasciitis.
A Closer Look At The Pathology And Factors Associated With Plantar Fasciitis
Plantar fasciitis theoretically is the result of repetitive tensile overload. This causes changes in the plantar aponeurosis that can be either acute or chronic. In a 2003 study, Lemont introduced the term plantar fasciosis to de-emphasize the idea that inflammation is the cause of pain.4 Histopathologic studies have shown that patients with diagnosed plantar fasciitis have more disorganization of fibrous tissue similar to degenerative tendinosis rather than inflammation.
In 2011, Hafner and colleagues reviewed the pathology specimens of 97 patients, who had a plantar fasciectomy to address recalcitrant plantar fasciitis.5 The authors found that 25 percent of the specimens had a histological appearance of plantar fibroma or neoplasm, 21 percent had a histological appearance of inflammation without neoplasm and 54 percent had no neoplastic or inflammatory response.
Obesity is a factor in up to 70 percent of the patients presenting with plantar fasciitis.6 Running or standing for long periods may also contribute to the development of plantar fasciitis. Authors have commonly implicated heel spurs as a risk factor for plantar fasciitis and studies now show a positive correlation between plantar fasciitis and calcaneal spur formation.7 Additional factors include deficits in the flexibility of the plantar flexor muscles, which contributes to indirect stretching of the plantar fascia, increasing the risk of plantar fasciitis.8 Excessive pronation has been associated with plantar fasciitis. Cornwall and McPoil found that 81 to 86 percent of patients with plantar fasciitis also exhibited excessive pronation.9
Essential Insights On Diagnostic Imaging
Radiographs have limited usefulness in diagnosing recalcitrant plantar fasciitis other than determining the presence or absence of a calcaneal spur or fracture.8 The presence of a calcaneal spur alone is generally non-specific and frequently is not associated with symptoms of plantar fasciitis.
Ultrasound. In contrast, musculoskeletal ultrasound is extremely useful and reliable in accurately measuring the thickness of the plantar fascia.10 Ultrasound can also monitor the effects of different treatment interventions and guide therapeutic treatment approaches in patients with plantar fasciitis.11
Sagittal ultrasound of the plantar fascia shows echogenic collagen ligament fibers on a background of a low signal matrix. In a normal plantar fascia, there is often a thicker reflective band on both surfaces demarcating the ligament. Plantar fasciitis in contrast demonstrates marked swelling and loss of reflectivity and organization of the internal structure of the plantar fascia.12
Patients with chronic plantar heel pain are more likely to have plantar fascia thickness values greater than 0.4 cm.13 In 2011, Mahowald and colleagues determined that a reduction in plantar fascia thickness over time was a valid diagnostic tool to assess the effectiveness of new or existing treatment protocols.14 Furthermore, they found that a post-treatment decrease in plantar fascia thickness corresponded to a decrease in patients’ subjective reporting of pain.
Magnetic resonance imaging (MRI). I am currently the principal investigator in a four-year retrospective review of sports medicine patients with recalcitrant plantar fasciitis who subsequently had referrals for MRI. These patients had referrals based on the severity and duration of symptoms as well as the thickness of the plantar fascia measured by ultrasound.
Inclusion criteria included medial heel pain symptoms greater than six months and medial plantar fascial thickness greater than 0.50 cm as measured by ultrasound. Exclusion criteria included any prior injection therapy (i.e. cortisone, platelet rich plasma (PRP), dry needling or prolotherapy) as well as an initial sudden onset of symptoms consistent with plantar fascial rupture.
Preliminary 12-month results of the 20 patients revealed significant findings. Of the six patients with medial plantar fascial thicknesses greater than 0.8 cm, 66 percent had proximal tears in the plantar fascia and 83 percent had calcaneal bone marrow edema at the plantar fascial insertion medially. Of the three patients with medial plantar fascial thicknesses between 0.7 cm and 0.79 cm, 66 percent had proximal tears in the plantar fascia and 66 percent had calcaneal bone marrow edema at the plantar fascial insertion medially. Of the 11 patients with medial plantar fascial thicknesses between 0.5 cm and 0.69 cm, 45 percent had proximal tears in the plantar fascia and 90 percent had calcaneal bone marrow edema at the plantar fascial insertion medially.
Based on these preliminary findings, up to 65 percent of patients with an ultrasound measured plantar fascia thickness greater than 0.50 cm subsequently had an MRI confirmed plantar fascia tear. Up to 90 percent of patients with an ultrasound measured plantar fascia greater than 0.50 cm had MRI confirmed bone marrow edema of the calcaneus in the area of plantar fascial insertion with or without a tear.
It would therefore seem prudent that in cases of recalcitrant plantar fasciitis with ultrasound measured thicknesses greater than 0.50 cm, one should avoid corticosteroid injections entirely due to a possibility of additional tearing or, even worse, rupture. Instead, clinicians should first emphasize an initial period of immobilization (six to eight weeks) in a controlled ankle motion (CAM) walker followed by a combination of other conservative treatments that I will outline below.
Pertinent Pointers On Stretching, Night Splints And Taping
Although conservative treatments for plantar fasciitis have been in use for decades, the understanding and fine-tuning of these treatments continue to evolve. In no particular order, the generally accepted treatments for recalcitrant plantar fasciitis are as follows.
Stretching. There is little dispute that stretching for plantar fasciitis can be a beneficial treatment. The most appropriate type of stretching, however, seems to be changing. Earlier studies advocate plantar fascia stretching as being superior to Achilles tendon stretching for recalcitrant plantar fasciitis.15 Recent studies advocate posterior muscle group stretching or high-load strength training as being the most effective treatment for recalcitrant plantar fasciitis.16-18
Most studies are consistent in that patients should follow stretching or strengthening protocols for eight weeks.
In 2003, DiGiovanni and colleagues studied over 100 patients having recalcitrant plantar fasciitis for greater than 10 months.15 They found the most significant improvements occurred in patients who participated in an eight-week program of non-weightbearing plantar fascia stretches. This was in contrast to patients doing an eight-week program of weightbearing Achilles tendon stretching exercises.
Research has shown hamstring, gastrocnemius and soleus tightness to be present in patients having plantar fasciitis more so than unaffected patients.16 A 2011 study conducted by Labovits found that participants (86 of 210 feet) with hamstring tightness were 8.7 times more likely to experience plantar fasciitis then those participants without hamstring tightness.17
In 2014, Rathleff and coworkers conducted a randomized controlled study of 48 patients, comparing the effectiveness of daily plantar fascia stretching with shoe inserts to strength training every other day also with shoe inserts.18 High-load strength training consisted of single leg calf raises with a towel underneath the toes causing dorsiflexion, activating the windlass mechanism. The results showed significantly improved Foot Function Index Scores at three and 12 months for the strength training group.
Night splints. Authors have studied night splints in the treatment of post-static dyskinesia and found them to be an effective modality for the morning pain associated with plantar fasciitis.19,20
Taping. Physicians commonly use taping for treating recalcitrant plantar fasciitis. Several taping techniques exist and studies show that taping can be beneficial in the short-term management of plantar fasciitis.21 The long-term effects of taping have not had adequate study. Of the types of taping studied, the best evidence exists for low-Dye taping and calcaneal taping of the rearfoot in a less everted position.22,23
What The Literature Reveals About The Impact Of Orthoses
Orthoses. Researchers believe a pronated foot type increases the risk of developing plantar fasciitis.24 Physicians commonly prescribe custom orthoses when plantar fasciitis accompanies an excessively pronated foot. In these cases, the use of foot orthoses in patients with plantar fasciitis appears to reduce pain and increase function.25
Custom semi-rigid foot orthotics may significantly reduce the pain experienced during walking and may reduce more global measures of pain and disability in patients with chronic plantar fasciitis.26 Research has also found that custom orthoses reduce contact pressure distribution over the rearfoot area in comparison to flat insoles and bone spur pads.27
A recent study compared the effectiveness of three different types of prefabricated orthoses in reducing plantar fascial pain.28 The types of orthoses included non-supportive orthoses, soft supportive orthoses and plastic supportive orthoses. Non-supportive, thin orthoses had no effect on pain. Soft supportive and plastic orthoses both had a significant effect on reducing the severity of pain. Plastic orthoses were superior to soft supportive orthoses, concerning pain reduction and the duration of pain-free time.
A review of current scientific literature is inconclusive as to whether custom, semi-custom or prefabricated orthoses are the most appropriate choice when treating recalcitrant plantar fasciitis. However, in spite of the lack of universal consensus, most studies reviewed consistently advocate for some degree of supportive insole treatments as an appropriate choice when treating painful plantar fasciitis.
Emerging Evidence On Injections And ESWT
Injections. Physicians frequently use injections in cases of recalcitrant plantar fasciitis. Generally, injections fall into one of three types: corticosteroid injections, prolotherapy and autologous PRP. There has additionally been some evidence that suggests botulinum toxin type A (Botox, Allergan) is effective for chronic plantar fasciitis pain.29
For the past several years, autologous PRP treatment has been gaining traction as being more effective and safer than corticosteroid injections. A 2014 systematic literature review by Sandrey has shown otherwise.30 This review identified strong evidence that autologous growth factor injections do not improve plantar fasciopathy pain or function in comparison with corticosteroid injections, dry needling or exercise therapy treatments. Furthermore, Sandrey notes that after undertaking a comprehensive review of the literature, there is currently limited evidence to suggest that PRP injections are beneficial.
Extracorporeal shockwave therapy (ESWT). In early 2013, Aqil and colleagues performed a meta-analysis of relevant randomized controlled trials of ESWT between 1980 to 2013.31 They found that ESWT is a safe and effective treatment of recalcitrant plantar fasciitis refractory to non-operative treatments. Improved pain scores with the use of ESWT were evident 12 weeks after treatment. The evidence suggests patients maintain this improvement for up to 12 months.
In Conclusion
Plantar fasciitis can be a frustrating disorder to treat successfully. Success in recalcitrant cases is more likely to occur with a comprehensive treatment program as opposed to a one-size-fits-all approach to treatment. Fortunately, researchers are publishing more and more scientific studies about this subject, which will inevitably help physicians better direct treatment to optimize outcomes. It would therefore be of benefit to physicians to periodically review the latest research on treatments for recalcitrant plantar fasciitis and their rationale.
Dr. Sanders is an Adjunct Clinical Professor within the Department of Applied Biomechanics at the California School of Podiatric Medicine at Samuel Merritt University in Oakland, Calif. She is board certified by the American Board of Podiatric Medicine. Dr. Sanders is in private practice in San Francisco. She writes a monthly blog for Podiatry Today. One can access her blog at https://www.podiatrytoday.com/blog/594 .
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):303-310.
2. Tong KB, Furia J. Economic burden of plantar fasciitis treatment in the United States. Phys Ther. 2010; 8(4):11.
3. APMA Newsworthy Analysis, Foot Ailments Survey, January 2009, Kelton Research.
4. Lemont H, Ammirati KM, Usen N. Plantar fasciitis: A degenerative process (fasciosis) without inflammation. J Am Podiatr Med Assoc. 2003; 93(3):234-237.
5. Hafner S, Han N, Pressman MM, Wallace C. Proximal plantar fibroma as an etiology of recalcitrant plantar heel pain. J Foot Ankle Surg. 2011; 50(3):366.e1-366.e5.
6. Irving DB, Cook JL, Menz HB. Factors associated with chronic plantar heel pain: A systematic review. J Sci Med Sports Sports Med. 2006; 9(1-2):11-22; discussion 23-4.
7. Johal KS, Milner SA. Plantar fasciitis and the calcaneal spur: fact or fiction? Foot Ankle Surg. 2012; 18(1):39-41.
8. Kibler WB, Goldberg C, Chandler TJ. Functional biomechanical deficits in running athletes with plantar fasciitis. Am J Sports Med. 1991; 19(1):66-71.
9. Cornwall MW, McPoil TG. Plantar fasciitis: Etiology and treatment. J Orthop Sports Phys Ther. 1999; 29(12):756-760.
10. Crofts G, Angin S, Mickle KJ, Hill S, Nester CJ. Reliability of ultrasound for measurement of selected foot structures. Gait Posture. 2014; 39(1):35-39.
11. Mohseni-Bandpei MA, Nakhaee M, Mousavi ME, Shakourirad A, Safari MR, Vahab Kashani R. Application of ultrasound in the assessment of plantar fascia in patients with plantar fasciitis: A systematic review. Ultrasound Med Biol. 2014; 40(8):1737-1754.
12. McNally EG, Shetty S. Plantar fascia: Imaging diagnosis and guided treatment. Semin Musculoskel Radiol. 2010; 14(3):334-343.
13. McMillan AM, Landorf KB, Barrett JT, Menz HB, Bird AR. Diagnostic imaging for chronic plantar heel pain: A systematic review and meta-analysis. J Foot Ankle Res. 2009; 2:32.
14. Mahowald S, Legge BS, Grady JF. The correlation between plantar fascia thickness and symptoms of plantar fasciitis. J Am Podiatr Med Assoc. 2011; 101(5):385-389.
15. DiGiovanni BF, Nawoczenski DA, Lintal ME, Moore EA, Murray JC, Wilding GE, 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):1270-1277.
16. Bolivar YA, Munuera PV, Padillo JP. Relationship between tightness of the posterior muscles of the lower limb and plantar fasciitis. Foot Ankle Int. 2013; 34(1):42-48.
17. Labovitz JM, Yu J, Kim C. The role of hamstring tightness in plantar fasciitis. Foot Ankle Spec. 2011; 4(3):141-144.
18. Rathleff MS, Mølgaard CM, Fredberg U, Kaalund S, Andersen KB, Jensen TT, et al. High-load strength training improves outcome in patients with plantar fasciitis: A randomized controlled trial with 12-month follow-up. Scand J Med Sci Sports. 2014; Epub ahead of print.
19. Evans A. Podiatric medical applications of posterior night stretch splinting. J Am Podiatr Med Assoc. 2001; 91(7):356-360.
20. Lee WC, Wong WY, Kung E, Leung AK. Effectiveness of adjustable dorsiflexion night splint in combination with accommodative foot orthosis on plantar fasciitis. J Rehabil Res Dev. 2012; 49(10):1557-1564.
21. Podolsky R, Kalichman L. Taping for plantar fasciitis. J Back Musculoskelet Rehabil. 2014; epub May 27.
22. Landorf KB, Radford JA, Keenan AM, Redmond AC. Effectiveness of low-dye taping for the short-term management of plantar fasciitis. J Am Podiatr Med Assoc. 2005; 95(6):525-530.
23. Hyland MR, Webber-Gaffney A, Cohen L, Lichtman PT. Randomized controlled trial of calcaneal taping, sham taping, and plantar fascia stretching for the short-term management of plantar heel pain. J Orthop Sports Phys Ther. 2006; 36(6):364-371.
24. Irving DB, Cook JL, Young MA, Menz HB. Obesity and pronated foot type may increase the risk of chronic plantar heel pain: A matched case-control study. BMC Musculoskeletal Disorders. 2007; 8:41.
25. Lee SY, McKeon P, Hertel J. Does the use of orthoses improve self-reported pain and function measures in patients with plantar fasciitis? A meta-analysis. Phys Ther Sport. 2009; 10(1):12-18.
26. Gross MT, Byers JM, Krafft JL, Lackey EJ, Melton KM. The impact of custom semirigid foot orthotics on pain and disability for individuals with plantar fasciitis. J Orthop Sports Phys Ther. 2002; 32(4):149-157.
27. Chia KK, Suresh S, Kuah A, Ong JL, Phua JM, Seah AL. Comparative trial of the foot pressure patterns between corrective orthotics,formthotics, bone spur pads and flat insoles in patients with chronic plantar fasciitis. Ann Acad Med Sinagpore. 2009; 38(10):869-875.
28. Walther M, Kratschmer B, Verschl J, Volkering C, Altenberger S, Kriegelstein S, et al. Effect of different orthotic concepts as first line treatment of plantar fasciitis. Foot Ankle Surg. 2013; 19(2):103-107.
29. Zhang T, Adatia A, Zarin W, Moitri M, Vijenthira A, Chu R, et al. The efficacy of botulinum toxin type A in managing chronic musculoskeletal pain: A systematic review and meta analysis. Inflammopharmacology. 2011; 19(1):21-34.
30. Sandrey MA. Autologous growth factor injections in chronic tendinopathy. J Ath Train. 2014; 49(3):428-430.
31. Aqil A, Siddiqui MR, Solan M, Redfern DJ, Gulati V, Cobb JP. Extracorporeal shock wave therapy is effective in treating chronic plantar fasciitis: A meta-analysis of RCTs. Clin Orthop Rel Res. 2013; 471(11):3645-3652.
