Comparison of the Incidence of Intra-operative Fractures in Hip Hemi-arthroplasty Performed in Supine and Lateral Positions.

Purpose: The difficulty of femoral preparation with supine-position hip hemi-arthroplasty (HA) often leads to intra-operative fractures (IOFs). We aimed to clarify the incidence and types of IOFs in HA for hip fractures performed in the supine and lateral positions.

Materials and Methods: We retrospectively investigated cases of HA for acute femoral neck fractures from June 2013 to May 2018. We examined the incidence and types of IOFs according to different approaches. We defined supine-position in HA as the supine and hip-hyperextended (over-range) femoral preparation position, and lateral position as the lateral and hip-flexed femoral preparation position. We used a short tapered wedged stem.

Results: Supine-position HA was used in 46 patients (23.7%) and lateral-position HA in 148 patients (76.3%). IOFs in supine-position HA occurred in 8 patients (17.4%) and included five Vancouver AGT and three Vancouver B2 fractures. IOFs in lateral-position HA occurred in 3 patients (2.0%) and included one Vancouver AGT and two Vancouver B fractures. Supine-position HA was a risk factor for IOFs (adjusted odds ratio, 9.71; 95% confidence interval, 2.37-39.8; P <0.01).

Conclusion: Supine-position in HA is an IOF risk factor and significantly increases the incidence of great trochanter fractures of Vancouver type A.