Orthopaedic Outpatients, Waikato Hospital, Pembroke Street, Hamilton, New Zealand.
J Bone Joint Surg Am. 2013 Jan 16;95(2):146-50. doi: 10.2106/JBJS.L.00365.
Slipped capital femoral epiphysis is a condition with potentially severe complications. Controversy remains as to when to undertake prophylactic pinning. We aimed to assess the utility of the posterior sloping angle as a predictor for contralateral slip in a large, multi-ethnic cohort including Polynesian children with a high incidence of slipped capital femoral epiphysis.
All patients presenting to our hospital between 2000 and 2009 were identified and records were reviewed to determine demographic data and determine whether they subsequently developed a contralateral slip. The presenting radiographs were reviewed and the posterior sloping angle was measured. Patients with bilateral slips at presentation and those without initial radiographs were excluded.
Records and radiographs of 132 patients were analyzed for the posterior sloping angle in the unaffected hip. Forty-two patients who had subsequently developed a contralateral slip had a mean posterior sloping angle (and standard deviation) of 17.2° ± 5.6°, which was significantly higher (p < 0.001) than that of 10.8° ± 4.2° for the ninety patients who had had a unilateral slip. Children who had developed a subsequent contralateral slip were significantly younger (11.1 years) than those who had developed a unilateral slip (12.2 years) (p < 0.001). If a posterior sloping angle of 14° were used as an indication for prophylactic fixation in this population, thirty-five (83.3%) of forty-two contralateral slips would have been prevented, and nineteen (21.1%) of ninety hips would have been pinned unnecessarily. The number needed to treat to prevent one subsequent contralateral slip is 1.79.
To our knowledge, this is the largest study to date that confirms that the posterior sloping angle is a reliable predictor of contralateral slip and can be used to guide prophylactic pinning. The posterior sloping angle is applicable in the high-risk Polynesian population and could be useful in preventing future slips in populations that are difficult to follow up.
股骨头骨骺滑脱是一种潜在严重并发症的疾病。何时进行预防性钢钉固定仍存在争议。我们旨在评估后倾角度作为高发股骨头骨骺滑脱的多民族队列（包括波利尼西亚儿童）中对侧滑脱的预测指标的效用。
确定 2000 年至 2009 年期间在我们医院就诊的所有患者，并回顾记录以确定人口统计学数据，并确定他们是否随后发生对侧滑脱。回顾性分析未受累髋关节的初始 X 线片，测量后倾角度。排除双侧初次滑脱和无初始 X 线片的患者。
分析了 132 例患者的记录和 X 线片，以评估未受累髋关节的后倾角度。42 例随后发生对侧滑脱的患者的平均后倾角度（标准差）为 17.2°±5.6°，明显高于 90 例单侧滑脱患者的 10.8°±4.2°（p<0.001）。随后发生对侧滑脱的患儿明显比单侧滑脱的患儿年龄更小（11.1 岁对 12.2 岁）（p<0.001）。如果将 14°的后倾角度作为该人群预防性固定的指征，42 例对侧滑脱中的 35 例（83.3%）将得到预防，90 髋中 19 髋（21.1%）将不必要地固定。预防 1 例对侧滑脱所需的治疗数为 1.79。
据我们所知，这是迄今为止最大的研究，证实后倾角度是对侧滑脱的可靠预测指标，可用于指导预防性钢钉固定。后倾角度适用于高危波利尼西亚人群，在难以随访的人群中可能有助于预防未来的滑脱。
