Is medial soft tissue laxity more important than lateral laxity after total knee arthroplasty?

IF 1.6 4区医学 Q3 ORTHOPEDICS

Knee Pub Date : 2025-05-08 DOI:10.1016/j.knee.2025.04.016

Hideki Mizu-uchi , Shojiro Ishibashi , Shinya Kawahara , Takuro Yara , Yasuharu Nakashima , Darryl D. D’Lima

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引用次数: 0

Abstract

Background

The optimal range of soft tissue balance that consistently leads to better patient outcomes has yet to be identified in total knee arthroplasty. This study aimed to analyze the effect of soft tissue tightness on Knee Society Score by grouping patients by extent of medial or lateral laxity and mediolateral balance.

Methods

Varus and valgus laxity were measured using stress radiographs for 95 varus-deformed osteoarthritis knees (82 patients). The joint line angle and the joint gap were calculated using digital measurement software and computer-aided design models of the implants. We divided patients based on medial and lateral joint gaps into three groups: tight (<3 mm), intermediate (3–6 mm), and loose (>6 mm).

Results

Postoperative joint line angles averaged 5.1 (1.8)° for varus stress and −4.6 (2.1)° for valgus stress. Medial joint gaps under valgus stress were 3.5 (1.6) mm and lateral joint gaps under varus stress were 3.9 (1.4) mm. The intermediate medial laxity group had the highest knee scores, and satisfaction scores in particular were significantly better than the two other groups. Patients with intermediate lateral laxity achieved significantly greater postoperative flexion compared with that in the two other groups. There were no significant differences in Knee Society Scores or range of motion among the patients grouped by mediolateral balance.

Conclusions

Achieving intermediate medial laxity is more impactful than equal mediolateral balance for better postoperative outcome. Clinically undetectable medial tightness may be more common without an accurate ligament balancer during the surgery.

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全膝关节置换术后内侧软组织松弛是否比外侧软组织松弛更重要？

背景：在全膝关节置换术中，软组织平衡的最佳范围一直导致更好的患者预后尚未确定。本研究旨在分析软组织松紧度对膝关节社会评分的影响，通过对患者的内侧或外侧松弛程度和中外侧平衡进行分组。方法采用应力x线片对82例95例膝内翻变形骨关节炎患者进行内翻和外翻松弛测量。利用数字测量软件和计算机辅助设计模型计算种植体的关节线角和关节间隙。我们根据内侧和外侧关节间隙将患者分为三组：紧密（3mm）、中间（3 - 6 mm）和松散（6mm）。结果手术后关节线角平均内翻5.1（1.8）°，外翻- 4.6（2.1）°。外翻应力下内侧关节间隙为3.5 (1.6)mm，内翻应力下外侧关节间隙为3.9 (1.4)mm，中间内侧松弛组膝关节评分最高，尤其是满意度评分显著优于其他两组。与其他两组相比，中度外侧松弛的患者术后屈曲明显更大。根据中外侧平衡分组的患者在膝关节社会评分和活动范围方面没有显著差异。结论中等内侧松弛比中等内侧平衡对术后效果更有影响。临床上无法检测到的内侧紧绷可能更常见，在手术中没有准确的韧带平衡器。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Knee 医学-外科

CiteScore

3.80

自引率

5.30%

发文量

171

审稿时长

6 months

期刊介绍： The Knee is an international journal publishing studies on the clinical treatment and fundamental biomechanical characteristics of this joint. The aim of the journal is to provide a vehicle relevant to surgeons, biomedical engineers, imaging specialists, materials scientists, rehabilitation personnel and all those with an interest in the knee. The topics covered include, but are not limited to: • Anatomy, physiology, morphology and biochemistry; • Biomechanical studies; • Advances in the development of prosthetic, orthotic and augmentation devices; • Imaging and diagnostic techniques; • Pathology; • Trauma; • Surgery; • Rehabilitation.