Background:Distal femoral varus osteotomy (DFVO) is an established surgical procedure for addressing valgus malalignment across various knee conditions. However, the effect of DFVO on stress distribution within the femorotibial joint has not been explored through in vivo studies.Purpose:To (1) explore the distribution pattern of subchondral bone density across the proximal tibia in nonarthritic knees without arthritis and in those of patients with valgus knees, (2) assess changes in the pattern of bone density distribution in patients with valgus knees before and after medial closing-wedge (MCW) DFVO, and (3) determine the correlation between leg alignment and changes in bone density distribution.Study Design:Cohort study; Level of evidence, 3.Methods:The authors retrospectively analyzed clinical and radiographic data from 14 patients (14 knees; mean age, 44 years; 3 men, 11 women) treated with MCW-DFVO for lateral compartment osteoarthritis (OA) due to valgus malalignment, alongside a control group of 18 patients (18 knees; mean age, 21 years; 4 men, 14 women) without OA. The distribution patterns of subchondral bone density distribution on the femorotibial articular surface of the tibia were examined both preoperatively and >1 year postoperatively using computed tomography osteoabsorptiometry. Quantitative analyses were conducted on the locations and percentages of the high-density areas (HDAs) on the articular surface. The mean time between surgery and the postoperative radiograph and computed tomography absorptiometry imaging was 13.6 months (range, 11-19 months). The mean length of clinical follow-up was 28.7 months (range, 14-62 months) after surgery.Results:The mean proportion of HDA in the lateral compartment relative to the total HDA (lateral ratio) was significantly greater in the preoperative OA group (58.8%) compared with the control group (41.1%) ( P < .001). After MCW-DFVO, the mean lateral ratio in the OA group notably declined to 45.3% ( P < .001). The lateral ratio exhibited a significant correlation with the hip-knee-ankle angle in both the control ( r = 0.630; P = .011) and OA ( r = 0.537; P = .047) groups. Moreover, the alteration in the lateral ratio after MCW-DFVO showed a significant relationship with changes in the hip-knee-ankle angle ( r = 0.742; P = .002) and the mechanical lateral distal femoral angle ( r = −0.752; P = .002). Within the lateral compartment, HDAs in the 3 lateral regions of the 4 lateral subregions diminished after MCW-DFVO, whereas in the medial compartment, HDAs in the 3 lateral subregions saw an increase.Conclusion:The mean lateral ratio was significantly greater in the preoperative OA group compared with the control group. MCW-DFVO resulted in a redistribution of HDA from the lateral to the medial compartment of the proximal tibial articular surface. The extent of alignment correction after MCW-DFVO was closely linked to the shifts in HDA distribution, reflecting changes in stress distribution.

中文翻译：

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内侧闭合楔形股骨内翻截骨术后股胫关节的应力分布模式：使用计算机断层扫描骨吸收测定法的评估


背景： 股骨远端内翻截骨术 （DFVO） 是一种成熟的外科手术，用于解决各种膝关节疾病的外翻错线不良。然而，DFVO 对股胫关节内应力分布的影响尚未通过体内研究得到探索。目的： （1） 探讨无关节炎的非关节炎膝关节和外翻膝关节患者胫骨近端软骨下骨密度的分布模式，（2） 评估内侧闭合楔形 （MCW） DFVO 前后外翻膝关节骨密度分布模式的变化，以及 （3） 确定腿部对齐与骨密度分布变化之间的相关性。研究设计： 队列研究;证据水平， 3.方法： 作者回顾性分析了 14 例接受 MCW-DFVO 治疗外翻力线不良引起的外侧隔室骨性关节炎 （OA） 患者的临床和影像学数据 （14 个膝关节;平均年龄，21 岁;4 例男性，14 例女性），以及 18 例无 OA 的患者 （18 个膝关节;平均年龄，21 岁;4 例男性，14 例女性）。术前和术后 >1 年使用计算机断层扫描骨吸收测定法检查胫骨股骨关节面上软骨下骨密度分布的分布模式。对关节面上高密度区域 （HDA） 的位置和百分比进行定量分析。手术与术后 X 线片和计算机断层扫描吸收测定成像之间的平均时间为 13.6 个月 （范围，11-19 个月）。术后平均临床随访时间为 28.7 个月 （范围，14-62 个月）。结果： 术前 OA 组 （58.8%） 侧室 HDA 相对于总 HDA 的平均比例 （侧向比） 显著高于对照组 （41.1%） （ P < .001）。MCW-DFVO 后，OA 组的平均横向比显著下降至 45.3% （ P < .001）。横向比与对照组的髋膝踝角呈显着相关性 （r = 0.630;P = .011） 和 OA （r = 0.537;P = .047） 组。此外，MCW-DFVO 后侧比的变化与髋膝踝角的变化呈显着关系 （r = 0.742;P = .002） 和股骨外侧外侧角 （r = -0.752;P = .002）。在外侧隔室内，MCW-DFVO 后 4 个外侧亚区的 3 个外侧区域的 HDA 减少，而在内侧隔室，3 个外侧亚区的 HDAs 增加。结论： 与对照组相比，术前 OA 组的平均横向比显著升高。MCW-DFVO 导致 HDA 从胫骨近端关节面的外侧到内侧隔室的重新分布。MCW-DFVO 后对准校正的程度与 HDA 分布的变化密切相关，反映了应力分布的变化。