|
Year |
2002 |
|---|---|
|
Question Number |
100. |
|
Category |
Hip and Knee Reconstruction |
Question
During a total knee arthroplasty for an 18 degree valgus deformity, the femoral and tibial bone cuts are made and soft tissue tension assessed. In full extension, the lateral side is tight but the medial side is loose. In flexion, the medial and lateral soft tissues are well balanced. Which of the following structures should be released first?
1- Posterior cruciate ligament
2- Lateral collateral ligament
3- Iliotibial band
4- Lateral gastrocnemius tendon
5- Posterolateral capsule
Figures
Answer (click for answer)
Answer-3- Iliotibial band
The PCL is tight in flexion and loose in extension, cutting it doesn’t help balance the soft tissue in extension. The LCL is more or less tight through out range of motion and sectioning will mess change the flexion and extension gaps. The posterior capsule and lateral gastrocnemius are both tight in extension and loose in flexion, so these are possibilities but they are not a easy to perform and control the amount of release. And they usually result in only small changes in the soft tissue balance. The ITB is tight in extension and loose in flexion, it is easily released, partially or fully, and can be performed in a controlled manor. Therefore it is the first structure released in the given scenario.
Reference: Whiteside LA: Selective ligament release in total kne arthroplasty of the knee in valgus. Clin Orthop 1999;367:130-140.