BACKGROUND Perfusion MRI (pMRI) can quantify femoral head hypoperfusion in early-stage Legg-Calvé-Perthes disease. We investigated whether the severity of hypoperfusion measured at the early stage correlates with femoral head deformity at intermediate-term follow-up. METHODS Sixty-three patients who were 5 to 11 years of age at the diagnosis of Legg-Calvé-Perthes disease and who had pMRI performed at an early stage (Waldenström Stage 1 to 2a) were retrospectively reviewed. Twenty-eight patients were treated nonoperatively and 35 were treated with proximal femoral varus osteotomy (PFVO). The sphericity deviation score (SDS) was used as the primary outcome. Femoral head perfusion and SDS were measured by 2 observers. Models assessing the relationship between hypoperfusion and SDS were fitted without and with stratifications by age at diagnosis and treatment method. RESULTS All 63 patients had a minimum of 4 years of follow-up (mean follow-up, 7.5 ± 2.6 years). All had reached the healed stage (Stage 4), and their mean age was 15.6 ± 2.8 years. The SDS outcome showed a significant positive correlation with the hypoperfusion % (p < 0.001). In the <50% hypoperfusion range, the SDS indicated no-to-low deformity, with narrow variability of outcome. However, the SDS became exponentially worse and had a wider variability of outcome at the ≥50% hypoperfusion range. Multivariable analyses revealed age at diagnosis, hypoperfusion %, and treatment method as significant prognostic factors for SDS (p = 0.007, <0.001, and 0.042, respectively). When treatment outcomes were stratified by age at diagnosis and hypoperfusion %, PFVO showed significantly better SDS outcome than nonoperative treatment in patients with an age at diagnosis of ≥8 years and low (<50%) and intermediate (50% to 80%) hypoperfusion ranges (p = 0.036 and 0.021, respectively). CONCLUSIONS Our study found a significant relationship between femoral head hypoperfusion measured in early-stage Legg-Calvé-Perthes disease and femoral head deformity at intermediate-term follow-up. This study provides new insight into the relationship between early-stage femoral head hypoperfusion and deformity. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

中文翻译：

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早期股骨头灌注不足与 Legg-Calvé-Perthes 病中期随访时的股骨头畸形相关。


背景 灌注 MRI （pMRI） 可以量化早期 Legg-Calvé-Perthes 病的股骨头灌注不足。我们调查了早期测量的低灌注严重程度是否与中期随访时的股骨头畸形相关。方法 回顾性回顾了 63 例诊断为 Legg-Calvé-Perthes 病时年龄在 5 至 11 岁之间且在早期 （Waldenström 1 至 2a 期） 进行了 pMRI 的患者。28 例患者接受非手术治疗，35 例接受股骨近端内翻截骨术 （PFVO） 治疗。球形度偏差评分 （SDS） 用作主要结局。股骨头灌注和 SDS 由 2 名观察者测量。评估低灌注与 SDS 之间关系的模型在诊断和治疗方法中按年龄进行无分层和有分层拟合。结果 所有 63 例患者均接受了至少 4 年的随访 （平均随访时间分别为 7.5 ± 2.6 年）。所有患者均已达到愈合阶段 （4 期），平均年龄为 15.6 ± 2.8 岁。SDS 结果显示与低灌注 % 呈显著正相关 （p < 0.001）。在 <50% 低灌注范围内，SDS 表明无到低畸形，结局变异性小。然而，SDS 呈指数级恶化，并且在 ≥50% 低灌注范围内具有更广泛的结果变异性。多变量分析显示诊断年龄、低灌注 % 和治疗方法是 SDS 的重要预后因素 （p = 0.007 、 <0.001 和 0.042，分别为 p = 0.007 、 <0.001 和 0.042）。 当按诊断年龄和低灌注水平对治疗结果进行分层时，PFVO 显示诊断年龄为 ≥8 岁且低 （<50%） 和中等 （50% 至 80%） 低灌注范围 （p = 0.036 和 0.021） 的患者的 SDS 结果明显优于非手术治疗 （p = 0.036 和 0.021，分别为）。结论 我们的研究发现，早期 Legg-Calvé-Perthes 病测量的股骨头灌注不足与中期随访的股骨头畸形之间存在显着关系。这项研究为早期股骨头灌注不足与畸形之间的关系提供了新的见解。证据级别 预后 III 级。有关证据级别的完整描述，请参阅作者说明。