Management of extensor mechanism rupture after TKA.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Reconstructive Surgery

Background:

• Disruption of the extensor mechanism in total knee arthroplasty (TKA) is a complex complication.
• It can arise from tubercle avulsion, patellar or quadriceps tendon rupture, or patella fracture, occurring intraoperatively or postoperatively.
• These disruptions are challenging to manage and associated with high failure and complication rates.

Purpose of the Study:

• To review the management strategies for extensor mechanism disruptions following TKA.
• To highlight surgical techniques and reconstructive options for acute and chronic cases.
• To emphasize the importance of proper graft fixation in preventing extensor lag.

Main Methods:

• Review of surgical management principles for extensor mechanism disruptions post-TKA.
• Discussion of repair techniques including cerclage wiring and local tendon augmentation.
• Exploration of reconstructive options for chronic cases with tissue loss, such as flaps and allografts.

Main Results:

• Conservative therapy is an option for quadriceps rupture if active extension is preserved.
• Surgical intervention is indicated for patellar fractures with component loosening or significant loss of extension (≥20°).
• Acute patellar tendon disruptions can be treated with primary repair, while chronic failures may require advanced reconstructive techniques.

Conclusions:

• Management of extensor mechanism disruptions requires tailored approaches based on the specific injury and chronicity.
• Augmentation with local tendons or grafts, along with cerclage wiring, is often necessary.
• Meticulous fixation in full extension is critical for allografts to prevent long-term extensor lag.