SRS31 - Identifying high-risk features in complex trochanteric femur fractures: predictors of fixation failure

Aims A distinct variant of trochanteric hip fracture is characterised by a short proximal fragment (femoral head and neck lying nearly horizontally on anteroposterior radiographs), combined with comminution of the greater trochanter causing medial displacement of the shaft from loss of lateral support. Angulation is often seen on lateral views. We hypothesised that this subtype is associated with higher fixation failure compared with typical trochanteric fractures. Methods We conducted a prospective cohort study of 4620 consecutive patients with AO/OTA 31A1–A3 trochanteric fractures (January 1989–February 2021). Patients were categorised into basal trochanteric fractures with greater trochanteric comminution (Group 1, n = 206, 4.4%) and all other trochanteric fractures (Group 2, n = 4414). Fixation failure—implant cut-out, plate detachment, non-union, implant breakage, secondary fracture, or avascular necrosis—was assessed with one-year follow-up. Results Fixation failure occurred in 21 (10.2%) of Group 1 compared with 148 (3.4%) of Group 2 (P < 0.0001; OR 3.26, 95% c.i. 2.01–5.26), specifically higher for plate detachment (OR 5.40; 95% c.i. 1.51–19.27). For the two most common fixation types, there was no difference in complication rate for Group 2 (3.1% with sliding hip screw [SHS] versus 3.8% with nail fixation). However, in Group 1, complication rates were almost twice as high with SHS (11.4%) compared with nail fixation (6.0%). Conclusions Basal trochanteric fractures with greater trochanteric comminution carry a significantly higher risk of fixation failure than other trochanteric fractures, particularly with SHS fixation. Recognition of this subtype should guide surgical strategy and further research into optimal management.