Do Cementless, Collared Stems Prevent Aseptic Loosening, Subsidence, and Periprosthetic Fracture in Total Hip Arthroplasty?

Modern total hip arthroplasty (THA) is one of the most common and successful orthopedic procedures performed, utilizing a variety of fixation methods, stem geometry and designs to provide immediate post-operative weight bearing. The purpose of this study was to determine the incidence of intraoperative periprosthetic fractures, subsidence rates and aseptic loosening between collared stems compared with non-collared tapered stems during THA. A retrospective chart review identified 983 THA cases performed by a single surgeon between 2013-2021. The average length of follow up was 1.5 years with an average duration of 533 d between initial and follow radiographs. Intraoperative fractures, subsidence and aseptic loosening were identified through chart review and X-rays. Chi square test, t-test, and descriptive statistics were conducted for both cohorts to determine statistical significance. There were 9 (2.05%) reports of intraoperative fractures in the collarless cohort and 3 (0.55%) reports of intraoperative fractures in the collared cohort. Subsidence values for those who received collarless stems ranged from 0-4.2 mm and had an average value of 0.59 mm. Those who received collared stems had subsidence values that ranged between 0-2.2 mm with an average of 0.23 mm. Patients who received collared stems had fewer incidences of intraoperative fracture within the first two weeks of surgery. Additionally, those who received collared stems had an average subsidence value of 0.23 mm, which was significantly less compared with those who received non-collard tapered stems with an average subsidence value of 0.59 mm. Utilizing cementless collared stems is beneficial in decreasing the rate of intraoperative fracture without increasing the rate of subsidence or loosening.