Background: Medial closing wedge distal femoral osteotomy (CWDFO) is used to correct valgus deformities and manage lateral osteoarthritis (OA) and patellar dislocation (PD). However, its effect on the tibial tuberosity–trochlear groove (TT-TG) distance remains debated, with limited studies evaluating contributing factors. Purpose: To determine whether TT-TG distance changes after CWDFO differ by the underlying diagnosis prompting the procedure and to identify preoperative factors influencing the extent of TT-TG distance changes. Study Design: Case series; Level of evidence, 4. Methods: This study analyzed 43 knees of 34 patients with valgus deformity who underwent CWDFO, categorized into the lateral OA (n = 14) and PD (n = 29) groups. Radiographic parameters, including the TT-TG distance, were assessed preoperatively and at least 1 year postoperatively. Regression analyses were conducted to identify the factors influencing TT-TG distance changes. A predictive model with 95% confidence intervals determined the thresholds for deviations from the expected values. Results: The TT-TG distance significantly decreased from 14.7 ± 5.1 to 11.5 ± 4.7 mm after CWDFO ( P < .001). On average, the TT-TG distance decreased by 21.8% after CWDFO. Changes in the TT-TG distance did not significantly differ by diagnosis (lateral OA: −3.0 ± 2.3 mm; PD: −3.3 ± 4.5 mm; P = .771). The preoperative TT-TG distance and osteotomy type significantly influenced TT-TG distance changes. A higher preoperative TT-TG distance was correlated with a greater reduction (odds ratio, −0.375; P = .001), and biplanar osteotomy showed a more pronounced effect than uniplanar osteotomy (odds ratio, −3.083; P = .013). Patients with preoperative TT-TG distances >23.5 mm demonstrated greater variability in TT-TG distance changes in the predictive model. Conclusion: CWDFO effectively reduced the TT-TG distance regardless of the diagnosis. Preoperative TT-TG distance and osteotomy type were key determinants of this reduction. In cases with preoperative TT-TG distances >23.5 mm, TT-TG distance changes demonstrated greater variability, suggesting that radiographic outcomes may deviate from expected values. These findings highlight the need for careful postoperative assessments and consideration of additional procedures in select cases.

中文翻译：

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根据诊断（外侧骨关节炎或髌骨脱位），内侧闭合楔形股骨远端截骨术对膝外翻患者胫骨结节-滑车沟距离的影响

背景：内侧闭合楔形股骨远端截骨术 （CWDFO） 用于矫正外翻畸形并治疗外侧骨关节炎 （OA） 和髌骨脱位 （PD）。然而，它对胫骨结节-滑车沟 （TT-TG） 距离的影响仍然存在争议，评估影响因素的研究有限。目的：确定 CWDFO 后 TT-TG 距离变化是否与促使手术的基础诊断不同，并确定影响 TT-TG 距离变化程度的术前因素。研究设计：病例系列;证据水平，4.方法： 本研究分析了 34 例接受 CWDFO 的外翻畸形患者的 43 个膝关节，分为外侧 OA （n = 14） 和 PD （n = 29） 组。术前和术后至少 1 年评估影像学参数，包括 TT-TG 距离。进行回归分析以确定影响 TT-TG 距离变化的因素。具有 95% 置信区间的预测模型确定了与预期值偏差的阈值。结果： CWDFO 后 TT-TG 距离从 14.7 ± 5.1 显著降低到 11.5 ± 4.7 mm （ P < .001）。平均而言，CWDFO 后 TT-TG 距离减少了 21.8%。TT-TG 距离的变化因诊断没有显著差异 （横向 OA： -3.0 ± 2.3 mm;局部放电：-3.3 ± 4.5 毫米;P = .771）。术前 TT-TG 距离和截骨类型显着影响 TT-TG 距离变化。 较高的术前 TT-TG 距离与较大的减少相关（比值比，-0.375;P = .001），双平面截骨术显示出比单平面截骨术更明显的效果（比值比，-3.083;P = .013）。术前 TT-TG 距离 >23.5 mm 的患者在预测模型中表现出 TT-TG 距离变化的较大变异性。结论： CWDFO 有效缩短了 TT-TG 距离，无论诊断如何。术前 TT-TG 距离和截骨类型是这种减少的关键决定因素。在术前 TT-TG 距离为 >23.5 mm 的病例中，TT-TG 距离变化表现出更大的变异性，表明影像学结果可能偏离预期值。这些发现强调了仔细的术后评估和考虑在特定病例中进行额外手术的必要性。