Modular Splined Tapered Stems Through the Direct Anterior Approach: Should I Make an Accessory Incision?

Abstract

Femoral preparation through a proximal accessory incision (PAI) has been suggested for placement of modular splined tapered stems (STSs) during revision direct anterior (DA) total hip arthroplasty. However, outcomes using PAIs have not been previously reported. The purpose of this study was to compare femoral revisions using a PAI with revisions in which all preparation was done through the Heuter interval, specifically looking for differences in: (1) survivorship, (2) complications, and (3) patient-reported outcomes. There were 36 hips that underwent DA femoral reconstruction with an STS revision stem by one of three fellowship-trained arthroplasty specialists at two orthopaedic teaching hospitals. The mean follow-up was 2.4 years. Electronic medical records were reviewed to determine if a PAI was made, to record rerevisions or major complications, and to collect demographic data and Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement scores. Continuous variables were analyzed using Student's t-test; categorical variables were analyzed using Fisher's exact test. A PAI was made in 16 hips (44%). In 20 hips (56%), all femoral preparation was done through the Heuter interval. Revision-free survivorship was found in 15 of 16 hips in the PAI group and 75% (15 of 20 hips) in the Heuter group (P = 0.2). A PAI hip sustained a major complication (dislocation; one of 16). Conversely, six hips (six of 20 hips, 30%) in the Heuter group suffered a major complication: three infections, one intraoperative femoral fracture, and two postoperative periprosthetic fractures (P = 0.1). Postoperative Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement scores were 91.3 (PAI) and 92.6 (Heuter; P = 0.84). The PAI is safe and effective for insertion of a modular STS during DA femoral revisions, compared to all femoral preparation done through the Heuter interval. Improved in-line reaming and less femoral elevation required with the PAI may limit the necessity for larger extensile exposures and aggressive femoral releases. There was a trend toward fewer major complications in the PAI group; however, this did not reach statistical significance with the numbers available.