Improved clinical outcome after medial open-wedge osteotomy despite cartilage lesions in the lateral compartment

Lisa Hohloch,Gerrit Bode,Julian Mehl,Norbert P Südkamp,Philipp Niemeyer,Helge Eberbach,Kaywan Izadpanah,Suchung Kim

doi:10.1371/journal.pone.0224080

Abstract

High tibial medial open-wedge osteotomy (HTO) is an established treatment option for cartilage lesions in the medial compartment. It was this study’s aim to evaluate the effect of asymptomatic single or kissing lesions in the lateral compartment on functional outcome after medial open-wedge osteotomy. A total of 156 patients were enrolled in this retrospective study. All patients underwent HTO due to a varus deformity and a symptomatic cartilage lesion or osteoarthritis in the medial compartment. We acquired preoperative Lysholm and VAS Scores. Each open-wedge osteotomy was preceded by diagnostic arthroscopy to ensure the compartments were thoroughly documented and diagnosed. Cartilage lesions in the lateral compartment were evaluated, and three groups created according to their individual characteristics: group A (no cartilage lesion, n = 119), group B (single cartilage lesion, n = 16) and group C (kissing lesions, n = 21). Cartilage lesions were graded according to the Outerbridge classification, The functional postoperative outcome was determined by relying on several parameters (VAS Score, Lysholm, KOOS, WOMAC Score). Pre- and postoperative long-leg axis views were analyzed via special planning software (mediCAD, Hectec GmbH Germany). Mean follow-up was at 69.0 ± 30.3 months after surgery (range 22 to 121 months). There were no significant differences between the three groups in the correction angle chosen (p = 0.16). Regarding the outcome parameters, group A attained the best results in the WOMACpain Score (p = 0.03) and WOMACfunction Score (p = 0.05). A higher Outerbridge-Score of cartilage lesions in the lateral compartment was associated with a higher (i.e., worse) WOMACpain Score (p = 0.018) and WOMACfunction Score (p = 0.033). In all the groups (A, B, and C), HTO led to a significant improvement in the Lysholm Score (p < 0.001) and to a decrease in pain level (VAS Score; p < 0.001). Conclusion: Valgus high tibial osteotomy leads to reduced pain and improved functional outcome scores, even in patients with pre-existing asymptomatic single or corresponding cartilage lesions in the lateral compartment. In case of severe cartilage lesions in the lateral compartment, surgeons should consider that clinical outcome worsens depending on the Outerbridge Score.

Highlights

High tibial osteotomy (HTO) has become an established and reliable treatment option for patients suffering from a varus deformity and symptomatic medial osteoarthritis (OA) or a cartilage lesion in the medial compartment.[1]
A worsening of lateral compartment cartilage damage in arthroscopic or MRI controls was not observed after valgus HTO, nor were significant morphologic changes detected in the lateral compartment [6,7,11,12,13]
This study aimed to evaluate the effects of valgus HTO on patients with pre-existing cartilage damage in the lateral compartment

Summary

Introduction

High tibial osteotomy (HTO) has become an established and reliable treatment option for patients suffering from a varus deformity and symptomatic medial osteoarthritis (OA) or a cartilage lesion in the medial compartment.[1] In a prior study, 96% of the patients examined required no conversion to total knee arthroplasty after a mean follow-up of 60.5 months after therapy with HTO[2]. Patients undergoing HTO for medial osteoarthritis should undergo early weight-bearing follow-up therapy [5]. Pain and significant cartilage lesions in the lateral compartment have traditionally been considered a contraindication to valgus HTO[1,11]. There has been no clinical evaluation of patients who have undergone valgus HTO despite the intra-operative detection of concomitant non-symptomatic cartilage lesions in the lateral compartment

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