Reliability of Modified Pauwels Angle in Preoperative Plain X-ray and Intraoperative Fluoroscope in Young Femoral Neck Fracture Fixation.

Abstract

This research aims to evaluate the reliability of modified Pauwels angle in preoperative plain X-ray and intraoperative fluoroscope. This study included 48 male and 18 female patients with an average age of 36.95years. Seven observers contributed to this study by measuring the modified Pauwels types and angles on 66 anterior-posterior (AP) views from preoperative radiographs and intraoperative fluorography. Intra-observer and inter-observer reliability was calculated using Fleiss's kappa and intraclass correlation coefficient (ICC). The results showed that the intra-observer reliability for the modified Pauwels type using Kappa coefficient in preoperative and intraoperative assessments was 0.584 and 0.823, respectively. The inter-observer reliability for preoperative and intraoperative evaluations was 0.467 and 0.753 for all observers, 0.647 and 0.783 for specialized trauma orthopedists, and 0.41 and 0.752 for the residents. The modified Pauwels angle assessment in intra-observers using ICC was 0.804 preoperatively and 0.943 intraoperatively. The inter-observer for preoperative and intraoperative assessments was 0.675 and 0.834 for all observers, 0.977 and 0.982 for specialized trauma orthopedists, and 0.622 and 0.823 for residents. The difference between preoperative and intraoperative modified Pauwels angles was 9.75 ± 6.76 (p < 0.05). Eleven patients had their modified Pauwels type changed, which altered the implant selection in 8 patients. The modified Pauwels angle together with type assessment has excellent reliability for implant selection when implemented intraoperatively, and at least two specialized trauma orthopedists should evaluate the fracture lines.