New York Presbyterian - Columbia University Medical Center, 622 West 168th Street, PH 1147, New York, NY 10032, USA.
Int Orthop. 2010 Jun;34(5):719-22. doi: 10.1007/s00264-009-0837-7. Epub 2009 Jul 18.
A tip-apex distance (TAD) of greater than 25 mm has been shown to be an accurate predictor of lag screw cut-out when sliding hip screws (SHS) are used to treat peritrochanteric (PT) hip fractures. The purpose of this study was to determine which factors, including TAD, correlated with successful clinical outcomes of PT hip fractures surgically treated with intramedullary (IM) devices. A total of 192 patients were included in this retrospective study. The TAD values of this cohort were radiographically analysed at a mean follow-up of 13 months. This was correlated with limited functional status and the rate of revision for implant failure or inability to achieve fracture union. Only 82 patients had adequate follow-up to fracture union or definitive failure. There were 46 intertrochanteric (IT) hip fractures and 36 subtrochanteric (ST) fractures. Overall, seven patients (8.5%) went on to experience lag screw cut-out. The average TAD of the patients who did not cut-out was 18 mm, compared to 38 mm for those who did (p = 0.012). All patients who cut-out had IT fractures (p = 0.017). The percentage of cut-outs correlated directly to both the severity of IT fractures and the TAD. Using a cutoff of 25 mm there was a statistically significant difference in the incidence of lag screw cut-out (p < 0.001). As in sliding hip screws, surgeons should strive for a TAD less than 25 mm when using IM devices in the treatment of PT hip fractures to help avoid lag screw cut-out.
尖端距（TAD）大于 25 毫米已被证明是滑动髋螺钉（SHS）治疗转子间（PT）髋部骨折时螺钉切出的准确预测指标。本研究的目的是确定哪些因素（包括 TAD）与使用髓内（IM）器械治疗 PT 髋部骨折的临床结果相关。共有 192 例患者纳入本回顾性研究。对该队列的 TAD 值进行了影像学分析，平均随访 13 个月。这与有限的功能状态以及因植入物失败或无法实现骨折愈合而进行翻修的比率相关。只有 82 例患者有足够的随访以达到骨折愈合或明确的失败。有 46 例转子间（IT）髋部骨折和 36 例转子下（ST）骨折。总体而言，有 7 例（8.5%）患者发生螺钉切出。未发生螺钉切出的患者的平均 TAD 为 18 毫米，而发生螺钉切出的患者为 38 毫米（p = 0.012）。所有发生螺钉切出的患者均为 IT 骨折（p = 0.017）。切出率与 IT 骨折的严重程度和 TAD 直接相关。使用 25 毫米的截止值，在螺钉切出的发生率方面存在统计学显著差异（p < 0.001）。与滑动髋螺钉一样，外科医生在使用 IM 器械治疗 PT 髋部骨折时，应努力使 TAD 小于 25 毫米，以帮助避免螺钉切出。
