Sagittal Angulation and the Treatment of Geriatric Femoral Neck Fractures: Time to Update our Classification Systems

Abstract

Objectives: Inconsistent outcomes have been reported for percutaneous fixation of Garden I/II femoral neck fractures in geriatric patients. It was hypothesized that accounting for variable follow-up would better estimate the failure rate of percutaneous fixation with and without significant sagittal angulation.

Design: Retrospective.

Setting: Single academic healthcare system.

Patient selection criteria: Patients ≥50 years of age treated with percutaneous screw fixation of Garden I/II (OTA/AO B1.1/B1.2) femoral neck fractures from 2010 to 2020 were identified. Pathologic fractures and open approaches were excluded.

Outcome measures and comparisons: Sagittal angulation was measured using a previously described method. 11 Treatment failure was defined as early fixation failure (within 6 weeks), nonunion, and/or avascular necrosis. Potential associations between treatment failure and patient, injury, and treatment variables were assessed. Cox proportional hazard analysis accounted for variable follow-up when assessing for event-free survival.

Results: Of the 240 fractures that met inclusion criteria, there were 20 treatment failures (8%) and 33 fractures with sagittal angulation ≥20 degrees on lateral radiographs (14%). Failure-free survival at 2 years was 91% for patients with <20 degrees of posterior angulation and 52% for patients with ≥20 degrees of posterior angulation ( P < 0.0001). The hazard ratio, which incorporates variable follow-up, for failure with ≥20 degrees of posterior angulation was 6.36 ( P < 0.0001). No other factors were associated with treatment failure.

Conclusions: Significant posterior angulation (≥20 degrees) of Garden I/II femoral neck fractures is associated with a high failure rate after screw fixation. The authors suggest characterizing fractures with ≥20 degrees of sagittal angulation as Garden III fractures to better support surgical decision making.

Level of evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.