Shanghai Sixth People's Hospital Affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai, PR China.
The Second Affiliated Hospital of Harbin Medical University, Harbin, PR China.
Clin Orthop Relat Res. 2024 Oct 1;482(10):1801-1812. doi: 10.1097/CORR.0000000000003071. Epub 2024 Apr 19.
Treatment of femoral neck fractures in patients who are nongeriatric (≤ 60 years) is challenging because of high failure rates. Anatomic parameters influence the biomechanical environment for fracture healing, but their associations with clinical prognosis remains unclear.
QUESTIONS/PURPOSES: (1) Which anatomic parameter that is identifiable on pelvic radiographs shows a statistical correlation with a higher risk of clinical failure defined as nonunion, avascular necrosis (AVN), reoperation, and functional failure (decrease in Harris hip score reaching the minimum clinically important difference) in the screw fixation of femoral neck fractures among nongeriatric patients? (2) How does the influence of anatomic parameters on clinical prognosis manifest: directly or mediated by additional mechanisms?
This retrospective, multicenter study used a nationwide database in China. Between January 2014 and December 2020, we evaluated 1066 patients with femoral neck fractures with a median age of 53 years (interquartile range 46 to 56) and median follow-up period of 62 months. Anatomic parameters including femoral neck-shaft angle (NSA), femoral head radius, femoral neck width, femoral offset, acetabular center-edge angle, and acetabular sharp angle were variables of interest. The primary outcome was clinical failure including nonunion, AVN, reoperation, and functional failure (decrease in Harris hip score reaching the minimum clinically important difference). Risk factors for failure were first filtered using the Bayesian information criterion and then assessed with multiple regression adjusting for confounders. The mediation effect was further explored using model-based causal mediation analysis with a quasi-Bayesian Monte Carlo method.
Of all anatomic parameters we assessed, the contralateral NSA was associated with clinical failure, after adjusting for all potential covariates and confounding variables (adjusted odds ratio 0.92 [95% confidence interval 0.89 to 0.95]; p < 0.001). The optimal threshold for the NSA was 130°, with the highest Youden index of 0.27. Patients with an NSA < 130° (41% [441 of 1066]) demonstrated an increased occurrence of nonunion (15% [68 of 441] versus 5% [33 of 625]; p < 0.001), AVN (32% [141 of 441] versus 22% [136 of 625]; p < 0.001), functional failure (25% [110 of 441] versus 15% [93 of 625]), and reoperations (28% [122 of 441] versus 13% [79 of 625]). The impact of an NSA less than 130° on clinical failure was direct and substantially mediated by the type of displaced fracture (mediation proportion: 18.7%).
In our study of screw fixations for femoral neck fractures among nongeriatric patients, we identified that a contralateral NSA < 130° correlates with an increased risk of clinical failure including nonunion, AVN, functional failure, and reoperation. The effect is either direct or mediated through displaced fracture types. This is important for surgeons in order to recognize the elevated rate of clinical failure and nature of the challenging biomechanical environment, which should guide them in refining surgical details and selecting appropriate fixation and rehabilitation plans. Approaches to managing these fractures require further validation with large-scale clinical trials.
Level III, prognostic study.
治疗非老年（≤60 岁）患者的股骨颈骨折具有挑战性，因为失败率很高。解剖参数会影响骨折愈合的生物力学环境，但它们与临床预后的关系尚不清楚。
问题/目的：(1) 在非老年患者股骨颈骨折螺钉固定中，哪些可在骨盆 X 线片上识别的解剖参数与临床失败（定义为非愈合、股骨头坏死 (AVN)、再次手术和功能失败（Harris 髋关节评分下降达到最小临床重要差异）的风险较高相关？(2) 解剖参数对临床预后的影响是如何表现的：直接影响还是通过其他机制间接影响？
这是一项回顾性、多中心研究，使用了中国的一个全国性数据库。2014 年 1 月至 2020 年 12 月，我们评估了 1066 例股骨颈骨折患者，中位年龄为 53 岁（四分位距 46 至 56），中位随访时间为 62 个月。感兴趣的解剖参数包括股骨颈干角（NSA）、股骨头半径、股骨颈宽度、股骨偏移量、髋臼中心边缘角和髋臼锐度角。主要结局是包括非愈合、AVN、再次手术和功能失败（Harris 髋关节评分下降达到最小临床重要差异）在内的临床失败。首先使用贝叶斯信息准则筛选失败的危险因素，然后使用多回归模型调整混杂因素进行评估。使用基于模型的因果中介分析方法和拟贝叶斯蒙特卡罗方法进一步探索中介效应。
在我们评估的所有解剖参数中，调整所有潜在协变量和混杂变量后，对侧 NSA 与临床失败相关（调整后的优势比 0.92[95%置信区间 0.89 至 0.95]；p<0.001）。NSA 的最佳阈值为 130°，具有最高的 Youden 指数 0.27。NSA<130°的患者非愈合（15%[68/441]与 5%[33/625]；p<0.001）、AVN（32%[141/441]与 22%[136/625]；p<0.001）、功能失败（25%[110/441]与 15%[93/625]）和再次手术（28%[122/441]与 13%[79/625]）的发生率更高。NSA<130°对临床失败的影响是直接的，并且主要通过移位骨折类型进行介导（中介比例：18.7%）。
在我们对非老年患者股骨颈骨折螺钉固定的研究中，我们发现对侧 NSA<130°与临床失败（包括非愈合、AVN、功能失败和再次手术）的风险增加相关。这种影响要么是直接的，要么是通过移位骨折类型间接产生的。这对于外科医生来说很重要，因为这可以让他们认识到临床失败的发生率较高和具有挑战性的生物力学环境的性质，这应指导他们改进手术细节并选择合适的固定和康复计划。这些骨折的管理方法需要进一步通过大规模临床试验进行验证。
III 级，预后研究。
