Clinical Outcomes of Conical Hip Prosthesis Used In Primary Total Hip Arthroplasty

Congenital dysplasia of the hip, presence of intramedullary bony pedestals, and related pathologies present unique challenges to the orthopaedic surgeon when considering total hip arthroplasty (THA). In these circumstances, a conical prosthesis has proven to be effective. The purpose of this study is to report the short-term radiological and clinical outcomes of the Wagner Cone Prosthesis® (Zimmer Biomet, Warsaw, Indiana) utilized for a range of etiologies at a major North American healthcare system.

A retrospective study was performed at a single healthcare system between 2007 and 2018. Demographic variables, including age, sex, and laterality, as well as surgical variables, including femoral head size, neck-shaft angle, stem diameter, surgical approach, and indication for THA, were collected for each hip. Radiographs were also examined for subsidence, limb length discrepancy (LLD), and Crowe classification if the hip was dysplastic.

Thirty-one THAs were performed using a Wagner Cone Prosthesis®. No intraoperative or postoperative implant-related complications were reported. Fourteen hips were dysplastic, and of these, 10 were classified as Crowe I, one as Crowe II, two as Crowe III, and one as Crowe IV. No implant was observed to have subsidence greater than 1cm. The average LLD following arthroplasty was 1.38mm ± 9.4mm shorter than the contralateral side.

The Wagner Cone Prosthesis® serves as a useful implant for THA. In our sample, it had excellent survivorship, impressive postoperative radiographic measurements obtained from most recent follow up, minimal mean subsidence, and minimal complication rates.