Genu valgo artrósico severo: Prótesis de estabilidad aumentada en artroplastia primaria

Abstract

Purpose

This retrospective level 2 analysis evaluates the prosthesis type selected in our department for the treatment of the severe valgus knee and proposes a new classification for the valgus knee osteoarthritis.

Material and methods

A total knee arthroplasty with a constrained or hinged knee prosthesis was performed in 28 valgus knees. The average follow-up was 6.2 years. A new classification that considerates the ligament sufficiency status was developed in order to relate the different knee types with the different type of eventually needed implants.

Results

Constrained prosthesis was used in 17 patients with an attenuated medial collateral ligament, and a rotating hinge in 11 patients with incompetent medial collateral ligament and/or recurvatum. The postoperatory Knee Society Score was of 85 points. The valgus knee was classified in 5 types considering the knee valgus deformity, the ligament sufficiency and joint stability and wear.

Discussion

The classification proposed clearly defines the ligament status and valgus knee types, and it seems to be a comprehensive tool to select the appropriate prosthesis. Constrained prosthesis must be used on patients who present coronal instability with attenuated medial collateral ligament. Rotating hinges must be reserved for those patients who have medial collateral ligament incompetence, recurvatum, combined instability and/or severe muscular deficiency.

Level 3 of evidence.