Poster Examines Stem Design and Periprosthetic Fractures in Total Hip Arthroplasty via the Posterior Approach

A poster study presented at the 2024 AAOS Annual Meeting reported the results of a retrospective study examining the incidence of periprosthetic femur fractures (PFFs) in total hip arthroplasty (THA) performed via the posterior approach, as well as the influence of stem design on the incidence of intraoperative and early postoperative fractures and morphology. The study was presented by Neil H. Cochrane, MD, orthopaedic surgery resident at Duke University Medical Center in Durham, North Carolina.

“As the incidence of THA increases, the number of PFFs will also rise. Surgical approach and stem design have both been shown to influence the rate of PFF,” the authors wrote.

The analysis was conducted on primary posterior THAs performed between 2013 and 2021 by arthroplasty surgeons with fellowship training. Data were collected from 3,183 patients, including demographics, comorbidities, femoral stem design, incidence of PFFs <90 days postoperatively, and all-cause femoral revisions. stems were classified as single-wedge taper (n="1,192)," double-wedge taper (n="240)," and ream and broach (n="1,726).">

Univariable and multivariable analyses were employed to compare PFFs and aseptic femoral revisions. Cox regression was used to evaluate survival to femoral revision.

Twenty-five patients (0.8 percent) experienced intraoperative or early postoperative PFFs. Patients with PFFs were found to be older (mean age 68 years versus 63 years; P = 0.03), and most were women (76 percent versus 24 percent; P = 0.02).

The investigators found that double-wedge stems exhibited a significantly higher incidence of all-cause PFFs compared with single-wedge and ream and broach stems (3.6 percent versus 0.7 percent and 0.4 percent, respectively; P <0.01). specifically, double-wedge stems had a higher incidence of vancouver b2 pffs (0.8 percent versus 0.05 percent;>P = 0.04) compared with ream and broach stems, as well as greater incidence of intraoperative calcar fractures (2.0 percent) than single-wedge stems (0.3 percent; P = 0.02) and ream and broach stems (0.2 percent; P = 0.03).

Following regression analysis, the authors found that “Stem design was not independently associated with PFF or all-cause femoral revision.” They further stated, “Cox regression analysis demonstrated no difference in survival to femoral revision” based on stem design.

Overall, “PFF after THA done from the posterior approach is an uncommon complication,” the authors concluded, noting that “double-wedge taper stems may be associated with intra- and early postoperative PFFs, including those requiring femoral stem revision.”

Dr. Cochrane’s coauthors of “Does Femoral Stem Design Influence Periprosthetic Fracture Incidence and Morphology in Total Hip Arthroplasty?” are Christopher T. Holland, MD, MS; Michael P. Bolognesi, MD, FAAOS; Samuel S. Wellman, MD, FAAOS; Sean P. Ryan, MD; Taylor Stauffer, BS; and Thorsten M. Seyler, MD, PhD, FAAOS.

Cailin Conner is the associate editor of AAOS Now.