Effect of Varus-Producing Distal Femoral Osteotomy and High Tibial Osteotomy on Compartment Pressures and Contact Area at Varying Degrees of Knee Flexion.

Background

In patients with valgus alignment and degenerative changes in the lateral compartment, both distal femoral osteotomy (DFO) and high tibial osteotomy (HTO) can be used to unload the lateral compartment. Prior studies have shown that in valgus knees, the tibial wear is posterior and DFO exerts the greatest effect in extension; however, its effect is decreased as flexion angle rises.

Hypothesis

Medial closing-wedge (MCW) HTO would significantly decrease contact area, mean contact pressure (MCP), and peak contact pressure (PCP) in the lateral knee compartment through knee flexion to a greater extent compared with lateral opening-wedge (LOW) DFO.

Study Design

Controlled laboratory study.

Methods

MCWHTO and LOWDFO were performed, correcting a mean of 8° of valgus alignment, in 10 cadaveric knees using plate fixation. Tibiofemoral contact pressure of the medial and lateral compartments was measured in 0°, 30°, 60°, and 90° of knee flexion before and after osteotomy using thin electronic sensors and load applied through an Instron device. PCP, MCP, and contact area were measured for each condition.

Results

The lateral MCP was significantly decreased in the HTO state compared with the native state in 30° (

Conclusion

With varus corrections of 8°, MCWHTO was more effective at unloading the lateral compartment than LOWDFO. This effect was significant as the knee flexion angle increased. This study should be considered as one aspect of the surgical decision-making process.

Clinical Relevance

In patients with mild to moderate valgus deformity without hypoplastic lateral femoral condyle and without significant joint line obliquity, MCWHTO may improve offloading of the lateral compartment in flexion.

Informations de copyright

© The Author(s) 2024.

Déclaration de conflit d'intérêts

One or more of the authors has declared the following potential conflict of interest or source of funding: J.L. has received grants from Arthrex; education payments from Arthrex, Impact Ortho, Smith & Nephew, and Southtech Orthopedics; and hospitality payments from Stryker. C.S. has received grants from DJO and education payments from Smith & Nephew and Medinc of Texas. M.F. has received grants from Arthrex and education payments from Arthrex and Smith & Nephew. A.V. has received education payments from Gemini Mountain Medical, consulting fees from Arthrex and Stryker, nonconsulting fees from Arthrex and Smith & Nephew, honoraria from Vericel, and hospitality payments from Bodycad. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto. Ethical approval was not sought for the present study.