The effects of soft tissue lateral release on the stability of the ligament complex of the knee

Abstract

Purpose Valgus deformity presents a particular challenge in total knee arthroplasty. This condition regularly leads to contractures of the lateral capsular ligament complex and to overstretching of the medial ligamentous complex. Reconstruction of the knee joint kinematics and anatomy often requires lateral release. However, data on how such release weakens the stability of the knee are missing in the literature. This study investigated the effects of sequential lateral release on the collateral stability of the ligament complex of the knee in vitro. Methods Ten knee prostheses were implanted in 10 healthy cadaveric knee joints using a navigation device. Soft tissue lateral release consisted of five release steps, and stiffness and stability were determined at 0, 30, 60 and 90° flexion after each step. Results Soft tissue lateral release increasingly weakened the ligament complex of the lateral compartment. Because of the large muscular parts, the release of the iliotibial band and the M. popliteus had little effect on the stability of the lateral and medial compartment, but release of the lateral ligament significantly decreased the stability in the lateral compartment over the entire range of motion. Stability in the medial compartment was hardly affected. Conversely, further release of the posterolateral capsule and the posterior cruciate ligament led to the loss of stability in the lateral compartment only in deep flexion, whereas stability decreased significantly in the medial compartment. Conclusion Our study shows for the first time the association between sequential lateral release and stability of the ligamentous complex of the knee. To maintain the stability, knee surgeons should avoid releasing the entire lateral collateral ligament, which would significantly decrease stability in the lateral compartment.

Pre-Planning the Surgical Target for Optimal Implant Positioning in Robotic-Assisted Total Knee Arthroplasty

“…In the objective function for surgical targets 1 and 2, the kinematic variables and ligament strains were weighted equally. To account for the important role of the collateral ligaments in controlling the joint stability [37,38], we re-executed the optimization process, assigning an eight-fold increased weighting to the medial and lateral collateral ligaments in Equation (1) (surgical target 3). This choice aimed to approximate more closely the prediseased functioning behavior of those ligaments during the entire range of motion.…”

Arthroscopic anatomy of the posterolateral corner of the knee: anatomic relations and arthroscopic approaches

“…The PLC comprises the fibular collateral ligament (FCL), which stabilizes mainly against varus stress, and the posterior-and posterolateral stabilizing popliteus complex, which itself consists of the popliteus muscle/tendon unit (PLT), the popliteofibular ligament (PFL), the fabellofibular ligament and the popliteomeniscal fibers [arcuate complex (AC)] [2]. PLC injuries may lead to an increased posterior, external rotational and/or varus instability and, thus, provide the biomechanical basis for graft failure following cruciate ligament reconstruction [3][4][5][6][7]. Accordingly, anatomic reconstruction techniques have been proposed to stabilize the PLC better than non-anatomic techniques [8][9][10].…”