Laterally Protruded Cephalomedullary Nail Lag Screws are a Source of Consistent Thigh Pain After Pertrochanteric Fracture.

Abstract

To assess the correlation between the amount of proximal screw lateralization and clinical symptoms in patients treated with a cephalomedullary nail (CMN) after a pertrochanteric fracture. Retrospective study. Level 1 trauma center. Patients operated for a pertrochanteric fracture (OTA/AO A1, A2, A3) between 2019 and 2022 and treated with a CMN were included. Three measurements were evaluated: D1 distance between the most laterally prominent point of the lag screw and the line tangent to the greater trochanter, D2 distance between the lateral femoral cortex and the most laterally prominent point of the lag screw, and D3 distance between the point where the lag screw emerges at the lateral edge of the femur shaft and the skin's surface. Clinical scores and information regarding lateral thigh pain were obtained, and a correlation analysis was performed. Mean age of the study cohort (n = 134) was 77.9 ± 12.3 years. Patients with categorical protrusion (considered present in cases where the distance between the lateral tip of the lag screw and the lateral border of the greater trochanter was ≥0.2 mm) had significantly higher rates of lateral thigh pain ( P = 0.007) and discomfort while lying on the side ( P = 0.032) compared with those without protrusion. Correlation analyses showed a positive correlation between measurements D1 and D2 and lateral thigh pain (r = 0.324 and r = 0.334, respectively, P < 0.001) and a negative correlation between D3 and lateral thigh pain (r = -0.286, P = 0.001). Regression analysis showed that higher D1 and D2 distances and shorter D3 distances are risk factors for lateral thigh pain ( P = 0.001, 0.001, and 0.002, respectively). Increasing lateral protrusion of the lag screw leads to significantly greater clinical complaints and lateral hip pain in patients treated with a CMN. Patients with lower distance between the lateral femoral wall and the skin are at higher risk of lateral pain. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.