Risk of Periprosthetic Fractures With Direct Anterior Primary Total Hip Arthroplasty.

BACKGROUND: Despite increasing interest in the anterior approach for cementless, primary total hip arthroplasty (THA), studies examining the incidence of periprosthetic fractures with this approach are lacking. The purpose of this study was to (1) investigate the incidence of early periprosthetic fractures associated with primary THA performed through an anterior supine intermuscular (ASI) approach without the use of a specialized table and (2) identify potential risk factors for these fractures.

METHODS: We identified 2869 primary THAs performed via the ASI approach using a single cementless, tapered titanium femoral component with short and standard length options between February 2007 and April 2014. Fifty-two percent of THAs were in female patients, whereas 48% were in males. Short stems were used in 59% vs standard length in 41%.

RESULTS: There were 26 (0.9%) early periprosthetic femoral fractures, with 23 requiring revision. When looking at the potential risk factors of age, gender, body mass index, and stem length, the only significant finding was that increased age was associated with increased risk of femoral fracture. Logistic regression analysis revealed a significant age-fracture association for female gender only, which remained when controlled for body mass index, stem length, or both.

CONCLUSION: The muscle-sparing ASI approach appears to be a safe technique for performing primary THA when used in a suitable patient population. The early periprosthetic femoral fracture rate in our series may warrant consideration of using a different design or different approach in elderly female patients.