Ido Hiroaki, Osawa Yusuke, Takegami Yasuhiko, Funahashi Hiroto, Ozawa Yuto, Asamoto Takamune, Imagama Shiro
Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya-shi, Japan.
Department of Orthopaedic Surgery, Japanese Red Cross Aichi Medical Center Nagoya Daini Hospital, Nagoya-shi, Japan.
Orthop Surg. 2025 Sep 17. doi: 10.1111/os.70172.
Curved intertrochanteric varus osteotomy (CVO) is a joint-preserving option for young patients with osteonecrosis of the femoral head (ONFH), but postoperative leg length discrepancy (LLD) remains a concern. This study investigated factors associated with leg shortening in both the early postoperative phase (P1) and the healing phase until bone union (P2).
This retrospective study included 48 patients (51 hips) with non-traumatic ONFH who underwent CVO. Radiographic evaluations were performed preoperatively, immediately postoperatively, and at bone union. Pearson's correlation coefficient was used to correlations between radiographic parameters and leg shortening in P1 and P2. Patients were divided into groups based on whether leg shortening ≥ 5 mm was observed in each phase, and statistical comparisons were conducted. Multivariate logistic regression analyses were performed to identify independent risk factors for leg shortening ≥ 5 mm.
Leg shortening ≥ 5 mm occurred in 17.6% of hips in P1 and 47.1% in P2. Lateral shift of the osteotomy arc center correlated with leg shortening in P1 (r = 0.689, p < 0.0001). Varus angle and changes in femoral anteversion were also correlated in both P1 and P2 (P1: r = 0.362/0.322; P2: r = 0.404/0.754, all p < 0.05). Greater varus angle and lateral/distal shift of the osteotomy center were significantly associated with P1 shortening. In P2, greater changes in femoral anteversion, increased osteotomy distance from the midpoint of the lesser trochanter, and larger varus angle were significant factors. Multivariate analysis identified lateral shift of the osteotomy center as an independent predictor in P1 (OR, 1.30; 95% CI, 1.06-1.81; p = 0.004). In P2, change in femoral anteversion was an independent predictor of leg shortening ≥ 5 mm (OR: 1.24, 95% CI: 1.07-1.51; p = 0.003).
Leg shortening post-CVO progresses during surgery and bone healing. Careful surgical planning and postoperative management, particularly in cases requiring extensive varus correction or anteversion changes, is essential for minimizing LLD and optimizing outcomes.
对于年轻的股骨头坏死（ONFH）患者，弧形转子间内翻截骨术（CVO）是一种保留关节的手术选择，但术后肢体长度差异（LLD）仍是一个令人担忧的问题。本研究调查了术后早期阶段（P1）和直至骨愈合的愈合阶段（P2）与腿部缩短相关的因素。
这项回顾性研究纳入了48例（51髋）接受CVO的非创伤性ONFH患者。在术前、术后即刻和骨愈合时进行影像学评估。使用Pearson相关系数分析P1和P2阶段影像学参数与腿部缩短之间的相关性。根据各阶段是否观察到腿部缩短≥5 mm将患者分组，并进行统计学比较。进行多因素逻辑回归分析以确定腿部缩短≥5 mm的独立危险因素。
P1阶段17.6%的髋关节出现腿部缩短≥5 mm，P2阶段为47.1%。截骨弧中心的外侧移位与P1阶段的腿部缩短相关（r = 0.689，p < 0.0001）。内翻角度和股骨前倾角的变化在P1和P2阶段也均有相关性（P1：r = 0.362/0.322；P2：r = 0.404/0.754，均p < 0.05）。更大的内翻角度以及截骨中心的外侧/远端移位与P1阶段的腿部缩短显著相关。在P2阶段，股骨前倾角的更大变化、截骨点距小转子中点的距离增加以及更大的内翻角度是显著因素。多因素分析确定截骨中心的外侧移位是P1阶段腿部缩短的独立预测因素（OR，1.30；95% CI，1.06 - 1.81；p = 0.004）。在P2阶段，股骨前倾角的变化是腿部缩短≥5 mm的独立预测因素（OR：1.24，95% CI：1.07 - 1.51；p = 0.003）。
CVO术后腿部缩短在手术期间和骨愈合过程中会进展。仔细的手术规划和术后管理，特别是在需要广泛内翻矫正或前倾角改变的病例中，对于最小化LLD和优化手术效果至关重要。
