Plantar Fascitis

                                Dr KS Dhillon

Introduction

Degenerative irritation of the plantar fascia at its origin at the heel causes plantar fasciitis. The plantar fascia plays an important role in the foot biomechanics. It comprises of three segments that arise from the calcaneus. The fascia supports the foot arch and absorbs shock. Although the condition is called fascitis there are no inflammatory cells in the fascia.

Plantar fasciitis is prevalent with many people experiencing heel pain. Although the cause of plantar fasciitis is multifactorial, most cases result from overuse stress. Classically it presents with sharp localized pain at the heel (1). Sometimes an X-ray may show a heel spur. Plantar fasciitis is often difficult to treat. Patient dissatisfaction is common. The treatment is nonsurgical in most cases.

Etiology

Plantar fasciitis is usually an overuse injury. It is primarily due to repetitive strain that causes micro-tears of the plantar fascia. It, however, can occur due to trauma or other causes. Some of the predisposing factors include pes cavus, pes planus, limited ankle dorsiflexion, prolonged standing or jumping, and excessive supination or pronation of the foot (2,3). Pes planus can increase strain at the origin of the plantar fascia. When there is pes cavus there can be excessive strain on the heel because the foot does not effectively evert or absorb shock. Patients with plantar fasciitis often have tightness in the soleus, gastrocnemius, and other muscles in the posterior leg. These tight muscles can alter the ambulatory normal biomechanics.

About 50% of patients with plantar fascitis have heel spurs. These spurs do not cause pain. Plantar fasciitis is often seen in runners and older adults. Other risk factors include heel pad atrophy, aging, obesity, occupations that require prolonged standing, and weight-bearing. Plantar fasciitis can be associated with various seronegative spondyloarthropathies. In about 85% of individuals, there are no known systemic factors.

Epidemiology

Heel pain is most commonly caused by plantar fasciitis. The exact prevalence and incidence of plantar fasciitis is not known. Annually about 1 million patient visits are due to plantar fasciitis. Plantar fasciitis accounts for about 10% of runner-related injuries and 11% to 15% of all foot symptoms. About 10% of the general population is affected by plantar fasciitis. Eighty-three percent of these patients are active working adults between the ages of 25 and 65 years. The peak incidence occurs in the general population between the age of 40 to 60 years (4). In about one-third of cases, the plantar fasciitis is bilateral. A higher prevalence of plantar fasciitis is seen in women as compared to men, in those aged 45 to 64 versus those aged 18 to 44, and in those with a body mass index >25 kg/m2 (5). In runners' prevalence rates as high as 22% have been reported.

Pathophysiology

Plantar fasciitis is essentially a degenerative condition. Besides the degenerative changes, the histological findings include granulation tissue,  collagen disarray, and micro-tears. There is a notable lack of traditional inflammation. Ultrasound often shows calcifications, intra-substance tears, and thickening and heterogeneity of the plantar fascia. These changes suggest a noninflammatory condition. A study by Jarde et al (6) which included magnetic resonance imaging showed chronic fasciitis in 8 cases and an old rupture of the plantar fascia in 30 patients. The micro-tears occur due to the repetitive stress of standing upright and weight-bearing.  The constant stretching of the plantar fascia due to standing upright and weight-bearing can lead to chronic degeneration of the fascia. This degeneration can eventually lead to pain during sleep or at rest.

History and Physical Examination

Patients usually present with progressive pain at the inferior medial aspect of the heel. In more severe cases the pain can radiate proximally. The patients often describe the pain as sharp and worse on getting up in the morning. Long periods of standing and sitting for prolonged periods can exacerbate the symptoms. Initially, pain decreases with ambulation and at the beginning of an athletic activity. It, however, increases throughout the day as the activity increases. 

Examination will show tenderness on the plantar aspect of the medial calcaneal tubercle at the site of the plantar fascial insertion. The pain can be reproduced by passive dorsiflexion of the foot and toes. The windlass or Jack test actively reproduces pain through passive dorsiflexion of the first metatarsophalangeal joint. It is positive if the pain is elicited (7). Secondary findings include a tight tendoachilles, pes cavus, or pes planus. 

The patient's gait should be evaluated for biomechanical factors or predisposing factors. Fat pad contusion or atrophy, stress fractures, and nerve entrapments such as tarsal tunnel syndrome should be considered in the differential diagnosis.

Evaluation

Plantar fasciitis is a clinical diagnosis. Imaging is of no value and is unnecessary. X-rays can be done and ultrasound evaluation can be carried out if the history or physical examination indicates other injuries or conditions or if the patient fails to improve after a reasonable amount of time. X-rays and ultrasound can show calcifications in the soft tissues or heel spurs on the inferior aspect of the heel (8). The ultrasound can show thickening and swelling of the plantar fascia (9). An MRI can be done to evaluate for tears, stress fractures, or osteochondral defects if the patient does not respond to conservative therapy after an extended time. 

In patients with plantar fasciitis, an MRI will show thickening of the plantar fascia and increased signal on inversion recovery (fat suppressed) images (10). Technetium scintigraphy can also successfully locate the inflammatory focus and exclude the presence of a stress fracture (11,12).

Management

Depending on the pain level, rest from the offending activity is the first-line treatment. Ice compresses and nonsteroidal anti-inflammatory drugs can help alleviate pain. Deep friction massage of the arch and insertion, along with the prescription of shoe inserts, orthotics, and night splints, can offer benefits (13). Prefabricated silicone heel inserts and stretching exercises, can also be helpful (14). The patients should be educated on proper stretching and rehabilitation of the Achilles tendon, plantar fascia, gastrocnemius, and soleus.

If the pain does not resolve with conservative measures, other more advanced or invasive techniques are required. These include botulinum toxin A, extracorporeal shock-wave therapy, or various injections such as dex prolotherapy, autologous platelet-rich plasma, or steroids (15-17). These more invasive and advanced techniques should be combined with conservative treatment. If conservative treatment fails then surgery may be required. For the therapy, a minimum of 6 weeks of treatment is required.  Stretching, icing, strapping of the heel, and modification of work-related activities are needed. A night splint can help patients who have recalcitrant pain (18).

Surgery is reserved as the last resort for treatment. It is usually reserved for patients who do not respond to nonoperative therapy for at least 6 to 12 months (19). A fasciotomy can be done through an endoscopic or open approach. A surgical release does not guarantee a successful outcome. Surgery can be associated with complications such as plantar fascia rupture, nerve injury, and flattening of the longitudinal arch. It is still uncertain whether stretching or controlling running intensity can prevent plantar fasciitis. Shock-absorbing footwear usually helps. A contoured foot orthosis can reduce injuries compared to a flat insole. 

Differential Diagnosis

Some of the differential diagnoses include:

Bone contusion

Neuropathic pain

Tendinitis

Calcaneus injury

Infection

Sickle cell bony pain

Osteoporosis

Malignancy

Considering and evaluating these conditions is important for an accurate diagnosis and proper treatment.

Prognosis

About 75% of cases resolve spontaneously within a year. Surgery is needed in about 5% of the patients. After surgery, the outcome is not consistently positive. The resolution of symptoms can take weeks to months after treatment (20). 

Plantar fasciitis requires time off from physically demanding work and sports and this can produce significant morbidity. Some patients will need an ambulatory device to avoid weight-bearing.

Complications

The following complications can result from plantar fasciitis:

• Fat pad necrosis

• Flattening of the arch

• Rupture of the tendon if corticosteroid injections are used

Conclusion

Plantar fasciitis is common and it affects many people, especially athletes and young people. If not appropriately managed it can be disabling. As no single treatment works for everyone, an interprofessional approach to plantar fasciitis is preferred. The doctor, physical therapist, pharmacist, and rehabilitation specialist are vital in managing symptoms and for patient education. Patients should be told that improvement in symptoms can take weeks or months. The patient may have to undergo physical therapy or wear a night splint. Patients should be taught how to stretch the plantar fascia through exercises.

Shoes with appropriate arch support may be required. The patient has to be advised to avoid long periods of standing. Individuals who are overweight have to lose weight. Stretching exercises have to be started. Individuals with acute symptoms have to avoid walking barefoot and limit repetitive exercises. 

Plantar fasciitis is a benign disorder, but if it is not adequately managed, it can be disabling and associated with moderate to severe foot pain. Symptom reduction occurs in 9 to 12 months in about 70% to 80% of patients. About 5% to 10% of the patients require surgical treatment (21). Plantar fasciitis in athletes can be associated with high morbidity despite appropriate treatment. Recurrences are not uncommon. The morbidity of plantar fasciitis is due to pain in the foot which produces difficulty in ambulation, limitation in doing exercises, and difficulty in weight bearing. Uneven ambulation can sometimes lead to hip and knee joint injury. Plantar fasciitis is one of the most common causes of worker's compensation claims in individuals who have to stand long hours.

References

1. Bm SA, Tiwari V, Bakde AM, Dwidmuthe S, Roy M. Ultrasonographic Assessment of Indian Patients With Plantar Fasciitis and Its Clinical Correlation: A Prospective Observational Study. Cureus. 2023 Mar;15(3):e35764.

2. Mørk M, Soberg HL, Hoksrud AF, Heide M, Groven KS. The struggle to stay physically active-A qualitative study exploring experiences of individuals with persistent plantar fasciopathy. J Foot Ankle Res. 2023 Apr 15;16(1):20.

3. Riddle DL, Pulisic M, Pidcoe P, Johnson RE. Risk factors for Plantar fasciitis: a matched case-control study. J Bone Joint Surg Am. 2003 May;85(5):872-7.

4. Nahin RL. Prevalence and Pharmaceutical Treatment of Plantar Fasciitis in United States Adults. J Pain. 2018 Aug;19(8):885-896.

5. LAPIDUS PW, GUIDOTTI FP. PAINFUL HEEL: REPORT OF 323 PATIENTS WITH 364 PAINFUL HEELS. Clin Orthop Relat Res. 1965 Mar-Apr;39:178-86.

6. Jarde O, Diebold P, Havet E, Boulu G, Vernois J. Degenerative lesions of the plantar fascia: surgical treatment by fasciectomy and excision of the heel spur. A report on 38 cases. Acta Orthop Belg. 2003 Jun;69(3):267-74.

7. Alshami AM, Babri AS, Souvlis T, Coppieters MW. Biomechanical evaluation of two clinical tests for plantar heel pain: the dorsiflexion-eversion test for tarsal tunnel syndrome and the windlass test for plantar fasciitis. Foot Ankle Int. 2007 Apr;28(4):499-505. 

8. Cho BW, Choi JH, Han HS, Choi WY, Lee KM. Age, Body Mass Index, and Spur Size Associated with Patients' Symptoms in Plantar Fasciitis. Clin Orthop Surg. 2022 Sep;14(3):458-465.

9. Lai TW, Ma HL, Lee MS, Chen PM, Ku MC. Ultrasonography and clinical outcome comparison of extracorporeal shock wave therapy and corticosteroid injections for chronic plantar fasciitis: A randomized controlled trial. J Musculoskelet Neuronal Interact. 2018 Mar 01;18(1):47-54.

10. McGonagle D, Marzo-Ortega H, O'Connor P, Gibbon W, Pease C, Reece R, Emery P. The role of biomechanical factors and HLA-B27 in magnetic resonance imaging-determined bone changes in plantar fascia enthesopathy. Arthritis Rheum. 2002 Feb;46(2):489-93. 

11. Drake C, Whittaker GA, Kaminski MR, Chen J, Keenan AM, Rathleff MS, Robinson P, Landorf KB. Medical imaging for plantar heel pain: a systematic review and meta-analysis. J Foot Ankle Res. 2022 Jan 22;15(1):4. 

12. Dasgupta B, Bowles J. Scintigraphic localisation of steroid injection site in plantar fasciitis. Lancet. 1995 Nov 25;346(8987):1400-1. 

13. Wapner KL, Sharkey PF. The use of night splints for treatment of recalcitrant plantar fasciitis. Foot Ankle. 1991 Dec;12(3):135-7. 

14. Pfeffer G, Bacchetti P, Deland J, Lewis A, Anderson R, Davis W, Alvarez R, Brodsky J, Cooper P, Frey C, Herrick R, Myerson M, Sammarco J, Janecki C, Ross S, Bowman M, Smith R. Comparison of custom and prefabricated orthoses in the initial treatment of proximal plantar fasciitis. Foot Ankle Int. 1999 Apr;20(4):214-21.

15. Majidi L, Saeb F, Alaei B, Khateri S, Ezzati Amini E, Nikoo MR. Comparison of the Effectiveness of Local Corticosteroid Injection and Extracorporeal Shockwave Therapy in Patients With Pes Anserine Bursitis: An Open-Label Randomized Clinical Trial. Med J Islam Repub Iran. 2023;37:10. 

16. Sneed D, Wong C. Platelet-rich plasma injections as a treatment for Achilles tendinopathy and plantar fasciitis in athletes. PM R. 2023 Nov;15(11):1493-1506. 

17. Karakılıç GD, Aras M, Büyük F, Bakırcı EŞ. Prolotherapy Versus Phonophoresis and Corticosteroid Injections for the Treatment of Plantar Fasciitis: A Randomized, Double-Blind Clinical Trial. J Foot Ankle Surg. 2023 May 07.

18. Nakhaee M, Mohseni-Bandpei M, Mousavi ME, Shakourirad A, Safari R, Kashani RV, Mimar R, Amiri H, Nakhaei M. The effects of a custom foot orthosis on dynamic plantar pressure in patients with chronic plantar fasciitis: A randomized controlled trial. Prosthet Orthot Int. 2023 Jun 01;47(3):241-252.

19. Davis PF, Severud E, Baxter DE. Painful heel syndrome: results of nonoperative treatment. Foot Ankle Int. 1994 Oct;15(10):531-5.

20. Fouda KZ, Ali ZA, Elshorbagy RT, Eladl HM. Effect of radial shock wave and ultrasound therapy combined with traditional physical therapy exercises on foot function and dorsiflexion range in plantar fasciitis: a prospective randomized clinical trial. Eur Rev Med Pharmacol Sci. 2023 May;27(9):3823-3832.

21. Martin RL, Irrgang JJ, Conti SF. Outcome study of subjects with insertional plantar fasciitis. Foot Ankle Int. 1998 Dec;19(12):803-11.