What are the symptoms and treatment options for a suspected patellar tendon rupture?

Symptoms and Treatment of Patellar Tendon Rupture

Patellar tendon rupture presents with an inability to actively extend the knee, a palpable gap in the tendon, and requires prompt surgical repair to restore function and prevent long-term disability.

Clinical Presentation

The classic symptoms of patellar tendon rupture include:

• Sudden pain at the front of the knee during activity, often accompanied by an audible "pop"
• Immediate inability to actively extend the knee or maintain extension against gravity
• Presence of a palpable gap or defect in the patellar tendon
• Superior displacement of the patella (patella alta) due to unopposed quadriceps contraction
• Significant swelling and bruising around the anterior knee
• Difficulty or inability to bear weight on the affected leg

Physical Examination Findings

The diagnosis can be established through physical examination with two or more of the following tests:

• Palpable gap or defect in the tendon just below the patella
• Decreased or absent knee extension strength
• Superior displacement of the patella compared to the unaffected side
• Inability to perform a straight leg raise against gravity

Diagnostic Imaging

While the diagnosis is primarily clinical, imaging can confirm the diagnosis:

• Plain radiographs may show patella alta (high-riding patella)
• MRI or ultrasound can confirm the diagnosis in unclear cases

Treatment Approach

Acute Management

• Surgical repair is the standard of care for patellar tendon ruptures to restore extensor mechanism function and allow early mobilization
• Surgery should be performed promptly (ideally within days of injury) to prevent retraction of the patella with subsequent adhesions and quadriceps contractures

Surgical Options

Several surgical techniques are available:

1. Primary repair - Direct end-to-end suturing through patellar drill holes using nonabsorbable sutures
2. Augmented repair - Primary repair with additional reinforcement:
   • Semitendinosus autograft augmentation
   • Wire cerclage
   • PDS cord augmentation

Post-Surgical Rehabilitation

• Early protected mobilization is recommended to prevent stiffness and muscle atrophy
• Continuous passive motion can be initiated early with a secure repair
• Progressive weight bearing and strengthening exercises

Outcomes and Prognosis

With proper surgical treatment and rehabilitation:

• Most patients can return to pre-injury activity levels
• Full range of motion can typically be achieved
• Quadriceps strength comparable to the uninjured side is possible
• Return to sports activities takes approximately 6-18 months

Special Considerations

• Chronic ruptures (>6 weeks) may require more complex reconstruction techniques due to tendon retraction and quadriceps contracture
• Bilateral ruptures are rare but may occur in patients with systemic conditions
• Patients with predisposing medical conditions may have poorer tissue quality requiring augmentation techniques

Potential Complications

• Extension lag (inability to fully extend the knee)
• Patellofemoral osteoarthritis
• Knee stiffness
• Re-rupture (uncommon with proper surgical technique)
• Infection (slightly higher with PDS cord augmentation)

Early diagnosis and prompt surgical intervention are critical for optimal outcomes in patellar tendon ruptures.