Extensor mechanism ruptures.

Area of Science:

• Orthopedic Surgery
• Sports Medicine
• Biomaterials Science

Background:

• Native patellar tendon injuries typically affect younger individuals, contrasting with quadriceps tendon ruptures.
• Risk factors for tendon injury include local (tendinopathy, cortisone injections) and systemic conditions (obesity, diabetes, renal failure, certain medications).
• Bilateral disruptions are more frequently associated with these risk factors.

Purpose of the Study:

• To review surgical repair and augmentation strategies for native and total knee arthroplasty (TKA) extensor mechanism disruptions.
• To compare outcomes between native tendon injuries and those occurring after TKA.
• To evaluate the efficacy of different augmentation techniques and salvage procedures.

Main Methods:

• Review of surgical outcomes for native patellar and quadriceps tendon tears.
• Analysis of factors influencing outcomes in TKA patients with extensor mechanism disruption.
• Assessment of augmentation techniques (autograft, allograft, synthetics) and salvage procedures.

Main Results:

• Complete extensor mechanism disruptions necessitate surgical intervention.
• Primary repair shows good outcomes in young patients with acute tears and good tendon quality.
• Augmentation is recommended for poor tendon quality, chronic tears, or defects, improving outcomes.
• High return-to-work/sport rates (>95%) are observed in native tendon injuries with low re-rupture rates (<5%).
• Extensor mechanism disruptions post-TKA present challenges (older age, comorbidities, local factors) leading to inferior outcomes compared to native injuries.
• Augmentation is advisable in all TKA cases.
• Salvage procedures like allografts offer acceptable outcomes for complex, multiply operated knees.

Conclusions:

• Surgical repair is the standard for complete extensor mechanism ruptures.
• Augmentation strategies are crucial for optimizing outcomes, particularly in cases with compromised tendon quality or chronic injuries.
• Extensor mechanism injuries in TKA patients have poorer prognoses, underscoring the need for augmentation and specialized salvage techniques.