Residual lateral wall width predicts a high risk of mechanical complications in cephalomedullary nail fixation of intertrochanteric fractures: a retrospective cohort study with propensity score matching.

Purpose: The purpose of this study is to determine whether the integrity of the entry portal of head-neck implant is related to postoperative mechanical complications. Methods: We retrospectively reviewed consecutive patients with pertrochanteric fractures in our hospital treated from January 1, 2018, to September 1, 2021. Based on the integrity of the entry portal for head-neck implants on the femoral lateral wall, patients were divided into two groups, including the ruptured entry portal (REP) group and the intact entry portal (IEP) group. After 4:1 propensity score-matched analyses were used to balance the baseline of the two groups, a total of 55 patients were extracted from the original participants, including 11 patients in the REP group and 44 matched patients in the IEP group. The anterior to posterior cortex width on the mid-level of the lesser trochanter was measured and defined as the residual lateral wall width (RLWW). Results: Compared with the IEP group, the REP group was correlated with postoperative mechanical complications (OR = 12.00, 95% CI 1.837–78.369, P = 0.002) and hip-thigh pain (OR = 26.67, 95% CI 4.98–142.86). RLWW ≤ 18.55 mm indicated a high likelihood (tau-y = 0.583, P = 0.000) of becoming the REP type postoperatively and being more likely to suffer from mechanical complications (OR = 30.67, 95% CI 3.91–240.70, P = 0.000) and hip-thigh pain (OR = 14.64, 95% CI 2.36–90.85, P = 0.001). Conclusion: Rupture of entry portal is a high-risk factor for mechanical complications in intertrochanteric fractures. RLWW ≤ 18.55 mm is a reliable predictor of the postoperative REP type. [ABSTRACT FROM AUTHOR]