In an older adult with a prior total knee arthroplasty, how should a high‑grade quadriceps tendon tear proximal to its insertion be treated?

Treatment of High-Grade Quadriceps Tendon Tear Proximal to Insertion After Total Knee Arthroplasty

Surgical reconstruction with augmentation using synthetic mesh, allograft, or autograft is the recommended treatment for high-grade (complete or near-complete) quadriceps tendon tears after TKA, as primary repair alone has unacceptably high complication and re-rupture rates. 1

Treatment Algorithm Based on Tear Severity

Complete (High-Grade) Tears

• Surgical reconstruction with augmentation is strongly recommended rather than primary repair alone, as the complication rate after simple repair of quadriceps tendon is 25.37% compared to 19.2% with reconstruction 1
• Reconstruction options include:
  • Synthetic mesh augmentation - provides good functional outcomes with mean Knee Society Score improvement from 55.7 to 87.3, average extensor lag of only 3.3°, and no reported complications at 19-month follow-up 2
  • Allograft or autograft reconstruction - similar complication rates to synthetic mesh (18.8% vs 19.2%) 1
• Early surgical intervention is critical - patients treated within 3 months of injury achieve better outcomes than delayed repairs 3, 4

Partial Tears

• Non-operative management is appropriate for partial tears and yields uniformly good outcomes with no complications 4
• Seven patients with partial tears treated conservatively all had satisfactory outcomes, while operative treatment of partial tears carries unnecessary risk 4
• If conservative management fails after appropriate trial, then consider surgical reconstruction with augmentation 2

Surgical Technique Considerations

The repair must be reinforced regardless of technique chosen, as the prevalence of complications is high (up to 25-63%) without augmentation 1:

• Use suture anchors to attach tendon to bone for improved fixation at the tendon-bone junction 5
• Synthetic mesh reinforcement has been validated specifically for quadriceps rupture after TKA with good functional outcomes 2
• The most common complication after any extensor mechanism repair is extension lag ≥30° (45.33% of cases), followed by re-rupture (25.33%) and infection (22.67%) 1

Post-Operative Protocol

• Immobilize knee in full extension for 6 weeks after surgical reconstruction 2
• Begin active movement at 3 weeks with knee cage protection 5
• Progress to full weight-bearing at 6 weeks with continued protection 5
• Controlled, gradual rehabilitation is essential - aggressive early mobilization increases re-rupture risk 3

Critical Prognostic Factors

Early ruptures (within 90 days of TKA) have higher overall complication rates than late injuries 1, 3:

• The incidence of quadriceps tendon tears after TKA is low at 0.17-2.5%, but when they occur, functional consequences are severe 6, 7
• Complete tears treated non-operatively have universally poor outcomes - only 1 of 11 patients had satisfactory results without surgery 4
• Primary repair without augmentation in complete tears results in re-rupture in 40% of cases (4 of 10 patients) 4

Diagnostic Confirmation

Before proceeding to surgery, confirm the diagnosis with:

• MRI with metal artifact reduction techniques - gold standard for evaluating quadriceps tendinopathy in TKA patients with 95% sensitivity and specificity 6, 7
• Ultrasound is an acceptable alternative with 94% specificity but lower sensitivity (58%) 7
• Plain radiographs show indirect signs including patella baja, soft-tissue swelling, and dystrophic calcifications 6, 7