What is the treatment for a full thickness tear of the semitendinosus and long head of the biceps femoris?

Treatment for Full Thickness Tear of Semitendinosus and Long Head Biceps Femoris

For acute full-thickness tears of the proximal hamstring musculotendinous junction involving the semitendinosus and long head of biceps femoris, surgical repair is the preferred treatment to enable rapid return to activity with low recurrence risk, particularly in active individuals seeking to return to sport. 1

Initial Assessment and Decision-Making

Determine timing and location of injury:

• Acute injuries (<6 weeks) at the proximal musculotendinous junction (MTJ) are surgical candidates, especially in athletes 1
• Chronic injuries (>1 year) without functional limitation may be managed conservatively 2
• Distal ruptures at the knee require surgical reconstruction with allograft 3

Surgical Management (Preferred for Acute MTJ Tears)

Primary surgical repair achieves superior outcomes:

• Return to preinjury sporting activity in 13.4 ± 5.1 weeks postoperatively 1
• Recurrence rate of only 1.6% for MTJ tears and 3.2% for myofascial tears 1
• All 64 patients in the highest quality study returned to preinjury activity levels 1

Surgical technique considerations:

• Direct repair of the musculotendinous junction is the standard approach 1
• For chronic distal biceps femoris ruptures at the knee, semitendinosus allograft reconstruction provides excellent outcomes 3

Expected functional recovery milestones at 3 months post-surgery:

• Passive straight-leg raise improves from 24.1° to 72.0° 1
• Isometric hamstring strength recovers to 84.5% at 0°, 89.5% at 15°, and 93.9% at 45° of knee flexion 1
• Lower Extremity Functional Scale scores improve from 29.8 to 71.5 1
• Marx activity rating scores improve from 3.8 to 9.8 1

Conservative Management (Alternative for Select Cases)

Conservative treatment may be considered only when:

• Patient has minimal functional demands or is unwilling to undergo surgery 2
• Injury is chronic (>1 year) with acceptable functional adaptation 2
• Patient accepts risk of prolonged recovery, decreased strength, and higher recurrence rates 2

Conservative protocol components:

• Relative rest while avoiding complete immobilization to prevent muscular atrophy 4, 5
• Eccentric exercise programs to stimulate collagen production and guide normal collagen fiber alignment 4, 5
• NSAIDs for pain management 4, 5
• Stretching exercises to maintain flexibility 4
• Cryotherapy for 10-minute periods through a wet towel 4

Critical Pitfalls to Avoid

Do not delay surgical intervention in acute cases:

• One case report showed full functional recovery without treatment, but the patient had persistent cosmetic deformity and hamstring tightness at 1 year 2
• This benign outcome is not generalizable to athletes requiring optimal performance 2

Avoid corticosteroid injections:

• Limited to single injections for short-term relief only, not repeated injections 5
• Deleterious effects when injected into tendon substance 4

Do not immobilize completely:

• Complete immobilization causes muscular atrophy and deconditioning 4, 5
• Tensile loading stimulates proper healing 4

Anatomical Considerations

Understanding the injury mechanism:

• The semitendinosus consistently originates from fibers of the long head of biceps femoris approximately 67mm distal to the ischial tuberosity 6
• This anatomical junction creates a horizontal vector that pulls the biceps femoris medially during contraction, representing an intrinsic risk factor for injury 6
• The conjoint tendon region where these muscles join is the most frequent location for hamstring injuries 6