Prognostic value of the sliding length of cephalocervical screws to predict the risk of non-union after osteosynthesis: a retrospective analysis of 86 patients with intracapsular femoral neck fractures

Abstract

BackgroundHere, we assessed the prognostic value of the early sliding length (ESL) for predicting the risk of non-union after internal fixation of femoral neck fractures (FNFs) by Dual SC Screws (DSCS).MethodsA retrospective analysis of 86 patients with intra-capsular FNFs was performed. They underwent osteosynthesis by DSCS at our institution between 2008 and 2013 with a minimum follow-up duration of 6 months. Preoperative displacement, fracture reduction quality, ESL of screws at 2 weeks postoperatively, and correlation of non-union with the ESL of screws were evaluated.ResultsBone union without complications was achieved in 74 patients (86.0%), whereas 12 patients (14.0%) showed non-union. The ESL was significantly longer in the non-union group (proximal 3.94 ± 2.79 mm, distal 4.03 ± 3.16 mm) than in the union group (proximal 0.98 ± 1.85 mm, distal 1.01 ± 1.84 mm, P = 0.0001* for proximal, P < 0.0001* for distal). The ESL was significantly associated with non-union, both in the proximal [P = 0.0002, unit odds ratio (OR) 1.58, 95% confidence interval (CI) 1.23–2.16] and distal screws (P = 0.0002, unit OR 1.53, 95% CI 1.21–2.02). The areas under the ROC curves for the ESL of proximal and distal screws were 0.845 and 0.867, respectively; the cut-off values to predict non-union were 1.0 mm (sensitivity 91.7% and specificity 74.3%) and 1.4 mm (sensitivity 83.3% and specificity 81.1%), respectively.ConclusionsIn this study, the ESL was a good predictor of postoperative non-union in patients with FNFs fixed by DSCS.

Dynamic finite element analysis of implants for femoral neck fractures simulating walking

“…Of the 53 Garden's Classification Stage I and II fractures treated with the DSCS system, all showed union except one case. 37 Although explicit comparative studies between these implants with Pauwels type III were not found, our results concurred with those of previous articles.…”