Comparison of augmentation effects of medial buttress plate versus trochanteric lag screw in the cannulated screw fixation of Pauwels type III femoral neck fractures: A retrospective clinical study.

Objective: This study aimed to compare the effects of a medial buttress plate (MBP) or a trochanteric lag screw (TLS) to augment cannulated screws (CSs) in fixing Pauwels type III femoral neck fractures.

Methods: This retrospective study included 58 patients (21 female, 37 male; mean age=46 years; age=19-64 years) treated by CSs for Pauwels type III femoral neck fractures from 2014 to 2017. All the patients were divided into 2 groups based on the internal fixation patterns: the MBP-augmented group (group A, n=26) and the TLS group (group B, n=32). The mean age was 47 (range=24-57) years in group A and 45 (range=19-64) years in group B. The operation time, intraoperative blood loss, reduction quality, Harris score, and postoperative complications were recorded and compared between both groups.

Results: All patients were followed up for an average of 44.8 months in group A and 47.3 months in group B (P=.406). No significant difference was noted in reduction quality (P=1.000). However, group A had a longer operation time (100.2 vs. 64.3 minutes, P < .001) and greater intraoperative blood loss (153.1 vs. 30.0 mL, P < .001) than group B. At the final follow-up, the union rate was equal between group A (96.2%) and group B (90.6%) (P=.760). The mean bone union time was 21.6 weeks in group A and 23.6 weeks in group B (P=.431). The delayed union rate was lower in group A (0%) than in group B (15.6%) (P < .001). The incidence of postoperative complications in terms of implant failure (7.7% vs. 28.1%, P=.048) and femoral neck shortening (7.7% vs. 28.1%, P=.048) were lower in group A than in group B. No significant difference was noted in avascular femoral head necrosis (P=1.000) and the Harris score (P=.659) between the 2 groups.

Conclusion: In the surgical treatment of Pauwels type III femoral neck fractures, medial buttress plating can offer fewer complications but equal avascular femoral head necrosis rate and functional outcome compared to trochanteric screw application.

Level of evidence: Level III, Therapeutic study.