Femoral Neck Fractures: Incidence, Reasons, and Risk Factors of Conversion From Hemiarthroplasty to Total Hip Arthroplasty.

Abstract

There is controversy over the choice of hemiarthroplasty (HA) versus total hip arthroplasty for treatment of femoral neck fractures in geriatric patients, especially those who are relatively healthy and active. A concern for selection of HA is that the patients may later require conversion to THA. All geriatric patients with femoral neck fractures who underwent HA were identified in the national PearlDiver data set. Patients were required to have 5 years of follow-up, and incidence of conversion was determined. Univariable and multivariable analyses were conducted to determine factors associated with conversion. The timing of conversion and reasons for conversions were determined. A total of 7,501 patients were identified with femoral neck fractures who underwent initial treatment with HA. Of those, 173 (2.3%) underwent conversion to THA within 5 years. On multivariable analysis, conversion was associated with patients being younger than 75 years (odds ratio: 1.64, P = 0.002) and having a higher Elixhauser Comorbidity Index (odds ratio: 1.04 per point, P = 0.018). Of the conversions performed over a five year period, 109 patients (63.0%) were within the 1st year. The most common reason for conversion to THA was degenerative causes (67.6%). Overall, there was a low rate (2.3%) of conversion from HA to THA for those who were tracked for 5 years after HA for femoral neck fracture. This low conversion rate is supportive that HA offers a durable answer for most patients for whom this treatment choice is pursued. III.