Assess and Release the Tight Ligament
The structure of the knee is complex, and its behavior can be unpredictable even in the most experienced hands. However, the task of replacing the bone surfaces and balancing the ligaments can be made manageable by following a logical plan based on correct alignment throughout the arc of flexion and ligament release based on the function of each ligament. Optimal knee function requires correct varus-valgus alignment in all positions of flexion. This requires reliable anatomical landmarks for alignment both in flexion and extension. The long axes of the femur and tibia and the anterior-posterior axis of the femur are highly reliable and provide the guidelines for establishing stable alignment of the joint surfaces by placing the tibia and patellar groove correctly in the median anterior-posterior plane through the entire arc of flexion. Ligaments perform specific functions, and these functions differ in different positions of knee flexion. Knowing their function and testing their tension provides the information necessary to release only the ligaments that are excessively tight, leaving those that are performing normally. Fractional release does not destabilize the knee, because other ligaments are retained, and because the peripheral attachments of the ligament to other soft-tissue structures such as the periosteum or synovial-capsular tissue allow the released ligament to continue to function. Ligament release does not cause instability. Failure to align the knee and release the tight ligaments, however, does cause instability, unreliable function, and excessive wear. With this knowledge, good instruments, and sound implants, the surgeon can align, balance, and stabilize the knee even when severe bone destruction and ligament contracture are present.
KeywordsTotal Knee Arthroplasty Posterior Cruciate Ligament Joint Surface Medial Collateral Ligament Lateral Collateral Ligament
Unable to display preview. Download preview PDF.
- 7.Whiteside LA (1995) Ligament release and bone grafting in total knee arthroplasty of the varus knee. Orthopedics 18:117–122Google Scholar
- 15.Whiteside LA, Summers RG (1983) Anatomical landmarks for an intramedullary alignment system for total knee replacement. Orthop Trans 7:546–547Google Scholar
- 16.Whiteside LA, Summers RG (1984) The effect of the level of distal femoral resection on ligament balance in total knee replacement. In: Dorr LD (ed) The knee: papers of the First Scientific Meeting of the Knee Society. University Park Press, Baltimore, pp 59–73Google Scholar