个体外翻矫正角度可提高全膝关节置换术后肢体对线恢复的准确性。

Individual valgus correction angle improves accuracy of postoperative limb alignment restoration after total knee arthroplasty.

作者信息

Shi Xiaojun, Li Hai, Zhou Zongke, Shen Bin, Yang Jing, Kang Pengde, Pei Fuxing

机构信息

The Orthopedic Department, West China Hospital, Sichuan University, Chengdu, China.

出版信息

Knee Surg Sports Traumatol Arthrosc. 2017 Jan;25(1):277-283. doi: 10.1007/s00167-014-3496-1. Epub 2015 Jan 1.

DOI:10.1007/s00167-014-3496-1

PMID:25552406

Abstract

PURPOSE

The purpose of the current study was to compare and investigate the effect of fixed and individual valgus correction angle (VCA) on postoperative alignment restoration. It is hypothesized that individual VCA would be more accurate than fixed VCA in postoperative limb alignment restoration.

METHODS

Four hundred and fifty-two patients with 546 consecutive uncomplicated primary total knee arthroplasties performed by a single surgeon, with 302 knees that had individual VCA (group A) and 244 knees that had fixed 5° VCA (group B), were enroled in this study. Preoperative and postoperative full-length standing hip-to-ankle radiographs were used to assess limb alignment. Postoperative hip-knee-ankle angle (θ), femoral component angle (α) and tibial component angle (β) were measured and compared between the two groups.

RESULTS

Mean postoperative θ angle and α angle were 178.9° (SD 1.3°) and 89.1° (SD 1.1°) in the group A, whereas they were 177.8° (SD 1.9°) and 87.9° (SD 1.5°) in the group B. There were significant differences in both parameters between the two groups (p = 0.021 and 0.016, respectively). Mean postoperative β was 89.8° (SD 1.2°) in the group A and 89.7° (SD 1.3°) in the group B, and no significant difference was detected. There were 114 (37.7 %), 221 (73.2 %) and 265 (87.7 %) knees that had restoration of mechanical axis to ±1°, ±2°, ±3° of neutral, respectively, and 37 (12.3 %) outliers (>±3°) in the group A, whereas there were 48 (19.7 %), 122 (50.0 %) and 170 (69.7 %) knees that had restoration of mechanical axis to ±1°, ±2°, ±3° of neutral, respectively, and 74 (30.3 %) outliers in the group B. Group A had a higher percentage of restoration of limb alignment and fewer outliers than those in the group B, and this difference was statistically significant (p < 0.001).

CONCLUSIONS

The results from the present study demonstrated that individual VCA for distal femoral resection could enhance the accuracy of postoperative limb alignment restoration compared with fixed VCA. For clinical relevance, individual VCA should be recommended for routine use in all patients in order to achieve the expected postoperative neutral limb alignment and reduce the risk of postoperative malalignment due to the planning error of a fixed VCA.

LEVEL OF EVIDENCE

Prospective comparative study, Level II.

摘要

目的

本研究旨在比较并探讨固定外翻矫正角度（VCA）与个体化VCA对术后力线恢复的影响。研究假设为，在术后肢体力线恢复方面，个体化VCA比固定VCA更准确。

方法

本研究纳入了由一名外科医生连续进行的452例无并发症的初次全膝关节置换术患者，共546个膝关节，其中302个膝关节采用个体化VCA（A组），244个膝关节采用固定5°VCA（B组）。术前和术后的全下肢站立位髋至踝关节X线片用于评估肢体力线。测量并比较两组术后的髋-膝-踝角（θ）、股骨假体角度（α）和胫骨假体角度（β）。

结果

A组术后平均θ角和α角分别为178.9°（标准差1.3°）和89.1°（标准差1.1°），而B组分别为177.8°（标准差1.9°）和87.9°（标准差1.5°）。两组在这两个参数上均存在显著差异（p分别为0.021和0.016）。A组术后平均β角为89.8°（标准差1.2°），B组为89.7°（标准差1.3°），未检测到显著差异。A组分别有114个（37.7%）、221个（73.2%）和265个（87.7%）膝关节的机械轴恢复到中立位±1°、±2°、±3°，37个（12.3%）膝关节为异常值（>±3°）；而B组分别有48个（19.7%）、122个（50.0%）和170个（69.7%）膝关节的机械轴恢复到中立位±1°、±2°、±3°，74个（30.3%）膝关节为异常值。A组肢体力线恢复的百分比高于B组，异常值少于B组，且这种差异具有统计学意义（p<0.001）。