Early Outcomes of Total Cementless Hip Joint Arthroplasty with Short-Stem Prothesis.

Abstract

Background: The steady increase in the number of implants of so-called short-stem hip endoprostheses has prompted clinical evaluation of new models being introduced to the market. The purpose of this study was to evaluate the clinical and radiological early results and experience of the new Medgal-HIp short-stem endoprosthesis implant.

Material and methods: This prospective study involved 121 patients at a mean age of 65.2 years (range 42-87) who underwent implantation of a short-stem Medgal-HIp cementless prosthesis. Clinical and radiological evaluations were performed the day before surgery and at 6 weeks, 6 months, 1 year and 2 years after surgery. Functional outcomes were assessed with the HHS scale and pain, with a VAS scale. Radiological examinations evaluated the presence of osteolytic foci, radio-opaque lines, ossifications and axial stem migration as well as limb length difference.

Results: Functional tests showed an increase in mean HHS scores at 2 years post-surgery from 39.1 points (range 34-56) to 88.9 points. (range 59-100) at p=0.041. The mean VAS pain score had decreased at 2 years from a value of 8.7 to 0.81 at p=0.012. No infections, thigh pain or periarticular fractures were noted in any patient. No foci of osteolysis or radio-opaque lines around the implant were noted on radiographs. Minor asymptomatic ossification (Brooker grade 1) appeared in 2 patients. In each case, stem healing occurred through osteointegration between 6 months and 2 years post-surgery. Mean axial migration of the stem was 1.6 mm (SD 1.79 mm and range from 0 to 6mm) at p <0.05. Limb length difference reached a mean value of 6.5 mm (SD 6.7 mm with a range from -11 mm to +12 mm) at p= 0.23. Two cases required revision surgeries related to the acetabulum. Survival of the prosthesis after 2 years according to Kaplan-Meier was 98.3% and that of the stem alone was 100%Conclusions 1. These early clinical results of the Medgal-HIp short-stem endoprosthesis are comparable to data regarding other commercially available short-stem implants. 2. The results of radiological analysis together with clinical results suggest that the stem of the endoprosthesis carries minimal risk of thigh pain, peri-prosthesis fracture or excessive stem migration. 3. Due to the short follow-up period, an authoritative evaluation of the implant will be possible when the distant outcomes are available.