Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Br J Radiol. 2012 Mar;85(1011):214-8. doi: 10.1259/bjr/44936440. Epub 2010 Dec 15.
The aim of this study was to identify the risk factors associated with the prognosis of a subchondral insufficiency fracture of the femoral head (SIF).
Between June 2002 and July 2009, 25 patients diagnosed with SIF were included in this study. Sequential radiographs were evaluated for the progression of collapse. Clinical profiles, including age, body mass index, follow-up period and Singh's index, were documented. The morphological characteristics of the low-intensity band on T(1) weighted MRI were also examined with regards to four factors: band length, band thickness, the length of the weight-bearing portion and the band length ratio (defined as the proportion of the band length to the weight-bearing portion of the femoral head in the slice through the femoral head centre).
Radiographically, a progression of collapse was observed in 15 of 25 (60.0%) patients. The band length in patients with progression of collapse [22.5 mm; 95% confidence interval (CI) 17.7, 27.3] was significantly larger than in patients without a progression of collapse (13.4 mm; 95% CI 7.6, 19.3; p<0.05). The band length ratio in patients with progression of collapse (59.8%; 95% CI 50.8, 68.9) was also significantly higher than in patients without a progression of collapse (40.9%; 95% CI 29.8, 52.0; p<0.05). No significant differences were present in the other values.
These results indicate that the band length and the band length ratio might be predictive for the progression of collapse in SIF.
本研究旨在确定与股骨头下骨不全骨折（SIF）预后相关的危险因素。
2002 年 6 月至 2009 年 7 月期间，共纳入 25 例 SIF 患者。对连续的 X 线片进行评估，以观察塌陷进展情况。记录了临床资料，包括年龄、体重指数、随访时间和 Singh 指数。还检查了 T1 加权 MRI 上低信号带的形态特征，共涉及四个因素：带宽、带厚、承重部分长度和带长比（定义为股骨头中心切片中带长与股骨头承重部分的比例）。
影像学上，25 例患者中有 15 例（60.0%）出现塌陷进展。有进展的患者的带宽[22.5mm；95%置信区间（CI）17.7，27.3]明显大于无进展的患者[13.4mm；95%CI 7.6，19.3；p<0.05]。有进展的患者的带长比（59.8%；95%CI 50.8，68.9）也明显高于无进展的患者[40.9%；95%CI 29.8，52.0；p<0.05]。其他值无显著差异。
这些结果表明，带宽和带长比可能是预测 SIF 塌陷进展的指标。
