What is the recommended management for flexor hallucis longus tendinopathy?

Management of Flexor Hallucis Longus Tendinopathy

Begin with 3-6 months of conservative management including relative rest, eccentric strengthening exercises, NSAIDs, and deep friction massage before considering surgical intervention. 1, 2, 3

Initial Conservative Treatment (First-Line for 3-6 Months)

Activity Modification and Rest

• Reduce activities causing repetitive loading of the FHL tendon, particularly movements requiring repetitive ankle plantarflexion or great toe flexion (common in ballet dancers, soccer players). 1, 4
• Avoid complete immobilization as this accelerates muscle atrophy and deconditioning. 2, 3
• Apply ice through a wet towel for 10-minute periods for short-term pain relief. 2, 3

Pharmacologic Management

• Use NSAIDs (oral or topical) for short-term pain relief, recognizing they provide symptomatic relief but do not alter the underlying degenerative process. 1, 2, 3
• Topical NSAIDs are preferred for localized tendinopathy as they provide similar pain relief with fewer systemic side effects. 2, 3
• Paracetamol up to 4g/day can be used as first-choice oral analgesic due to favorable safety profile. 3

Physical Therapy and Rehabilitation

• Eccentric strengthening exercises are the cornerstone of treatment, proven to reverse degenerative changes, reduce symptoms, and increase strength in tendinosis. 1, 2, 3
• Implement deep transverse friction massage to reduce pain. 1, 2, 3
• Stretching of the gastrocnemius-soleus complex is beneficial for posterior ankle tendinopathies. 1
• Therapeutic ultrasound may decrease pain and increase collagen synthesis, though evidence of consistent benefit is weak. 1, 2

Corticosteroid Injections (Second-Line)

• Consider corticosteroid injections for acute pain relief when conservative measures provide insufficient relief. 2, 3
• Injections are more effective than NSAIDs in the acute phase but do not change long-term outcomes. 1, 2
• Limit to maximum 2-3 injections as they may inhibit healing and reduce tensile strength. 2, 3
• Blind injection into the FHL tendon sheath based on clinical examination has high accuracy (90% in cadaveric study), though ultrasound guidance improves precision. 2, 5

Expected Timeline and Prognosis

• Approximately 80% of patients with overuse tendinopathies achieve full functional recovery within 3-6 months with appropriate conservative treatment. 2, 3
• Complete normalization of tendon strength often exceeds this 3-6 month period. 2

Surgical Management (After Failed Conservative Treatment)

Indications for Surgery

• Surgery is reserved for carefully selected patients who have failed 6 months of appropriate conservative management. 2, 3, 6, 4
• Persistent symptoms despite well-managed conservative therapy warrant surgical consultation. 3

Surgical Technique

• Arthroscopic release of the FHL tendon is the preferred approach, offering minimally invasive surgery with good visualization of involved structures. 6, 4
• Arthroscopic surgery involves release of the FHL tendon sheath, removal of any bony impingement (such as Stieda process fragments), and debridement of inflamed tissue. 6, 4
• Open surgical techniques are also effective but more invasive. 6, 4

Surgical Outcomes

• Mean postoperative AOFAS ankle-hindfoot scores of 89 with 70% excellent or good results. 4
• 81% of patients return to the same level of activity in work and sports. 4
• Mean satisfaction rate of 4 out of 5, with 89% of patients willing to undergo the procedure again. 4
• Complication rate of 18% and reoperation rate of 4%. 4

Clinical Pearls and Diagnostic Considerations

Key Physical Examination Findings

• Well-localized tenderness along the FHL tendon sheath (posterior ankle to medial calcaneus) that reproduces activity-related pain. 3, 7
• Pain with plantarflexion of the great toe, particularly in positions requiring maximal flexion. 6, 7
• Triggering of the great toe with audible and palpable crepitus during active and passive range of motion suggests stenosing tenosynovitis. 7
• Absence of joint effusion is typical; presence of effusion suggests intra-articular pathology requiring different management. 3

Common Pitfalls to Avoid

• Do not mislabel chronic cases as "tendinitis" when they represent degenerative tendinopathy ("tendinosis"), as this leads to inappropriate therapeutic choices. 2, 3
• The underlying pathology is degenerative tendinopathy rather than acute inflammation, explaining why anti-inflammatory treatments eventually fail. 2, 3
• FHL tendinopathy is not exclusive to ballet dancers or professional athletes; it can occur after ankle sprains or in recreational athletes. 4
• Never completely immobilize the ankle as this accelerates muscular atrophy and deconditioning. 2, 3

Advanced Treatment Options

• Extracorporeal shock wave therapy (ESWT) is a safe, noninvasive option for chronic tendinopathies refractory to other treatments, though expensive. 1, 2, 3
• ESWT may be considered before proceeding to surgery in patients who have failed standard conservative management. 2