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

Florian Völlner,Florian Herl,Joachim Grifka,Markus Weber,Tobias Renkawitz,Benjamin Craiovan,Felix Greimel,Achim Benditz

doi:10.1007/s00402-020-03422-6

Abstract

PurposeValgus 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.MethodsTen 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.ResultsSoft 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.ConclusionOur 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.

Highlights

Valgus deformity, which affects about 10% of patients undergoing total knee arthroplasty (TKA), presents a major challenge to surgeons
The present study describes the relation between sequential lateral release and the stiffness and stability of the medial and lateral knee ligament complex in vitro
The present model mirrors the most common load case. This is the first study that shows the association between sequential lateral release and weakening of the knee ligament complex

Summary

Introduction

Valgus deformity, which affects about 10% of patients undergoing total knee arthroplasty (TKA), presents a major challenge to surgeons. Some authors achieved good clinical results with sequential lateral release [2, 10, 12, 15, 17, 24], whereas Krackow et al preferred detachment of the ITB and LCL followed by detachment of the POP and PLC [10]. Böttner et al used a standardised soft tissue release technique of the ITB, PLC, LCL and the anterior lateral ligament, which had shown excellent clinical results at the 2-year follow-up [2]. Sequential lateral release was conducted as a part of total knee arthroplasty, and stiffness and stability of the knee ligament complex were determined at 0, 30, 60 and 90° flexion. Arthroplasty was conducted by one surgeon with 10 years of experience

Materials and methods

Discussion

Conclusion

Compliance with ethical standards