Summary
Knee instability in patients undergoing high tibial osteotomy due to varus degeneration has a negative impact on outcome. Especially reduced sport activity seems to correlate with lower clinical outcome. If sport activity can be increased with better knee stability one should consider ACL reconstruction combined with or after high tibial osteotomy.
Abstract
Introduction
Different knee pathologies result in varus degeneration of the knee joint and are then subject of axis correction (HTO). In this study we compared outcome of high tibial osteotomies in patients with medial degeneration and stable anterior cruciate ligament and patients with medial degeneration and instable knee joints due to failed ACL reconstruction or failed native ACL.
Methods
In a retrospective analysis 222 patients with varus degeneration of the knee and performed high tibial osteotomy (HTO) with a minimum follow-up of at least 5 years were evaluated. The cohort were split in an ACL instability group (Lachman>/=2 with firm/unsecure/soft endpoint) (n=105) and in an ACL stability group (Lachman <2 and firm endpoint) (n=117).
KOOS, demographic data, smoking status, BMI, sport status, daily workload were evaluated and correlated by regression analysis.
Results
The mean age was 42 years in the ACL instability group and 45 years in the ACL stable group without significant differences between the groups. 173 were males and 49 females with no significant difference between the groups. The mean correction angle was 6,9° ±2,5 with no significant differences between the groups.
The overall KOOS were 76 in the ACL stability group compared to 70 in the ACL instability group with significant difference (p<0.05).
Regression analysis revealed that in the ACL stable group higher BMI (ß= -0,35), higher workload (ß= -0,32) and lower sport activity (ß= -0,18) is associated with significant lower KOOS scores. In the ACL instability group only the reduced sport activity (ß= -0,36) showed significant lower KOOS scores.
Discussion
Knee instability in patients undergoing high tibial osteotomy due to varus degeneration has a negative impact on outcome. Especially reduced sport activity seems to correlate with lower clinical outcome. If sport activity can be increased with better knee stability one should consider ACL reconstruction combined with or after high tibial osteotomy.