Abstract

BAKKAI, A; RYAN, P  and  GOGA, IE. Tapered uncemented HA-coated femoral stems: a radiological study. SA orthop. j. [online]. 2017, vol.16, n.3, pp.27-30. ISSN 2309-8309.  http://dx.doi.org/10.17159/2309-8309/2017/v16n3a2.

INTRODUCTION: Numerous national joint registries demonstrate a trend towards the use of uncemented femoral components in total hip arthroplasty. While the results of first-generation uncemented, and some of the second-generation uncemented implants have been unacceptably poor, others, including the fully hydroxyapatite (HA) coated femoral stems, have been excellent with survival rates of greater than 95% at 20 years. Component longevity is largely related to robust stem fixation to native bone. Adequate stem fixation to the native bone can be determined by clinical assessment and radiological signs of osteointegration. The absence of these radiological signs might be an indication of early loosening. With this in mind, we performed a radiological analysis of the osteointegration of uncemented fully HA-coated femoral stems inserted at our arthroplasty unit. MATERIALS AND METHODS: We performed a retrospective chart and radiological review of patients who had undergone total hip replacement with an uncemented fully HA-coated femoral component over a five-year period. Between March 2003 and March 2008, 80 patients met the criteria used, and radiological changes around the femoral stem were analysed. The mean patient age at the time of surgery was 59 years, and the most common presenting pathology was avascular necrosis (43%). The immediate post-operative, six-week, six-month, one-year and five-year radiographs were evaluated. RESULTS: There were no revisions for stem-related complications. The earliest radiological signs of osteointegration, which included remodelling and trabecular bone formation, were noticed as early as six weeks post-operatively in 4%. At six months and one year, these had increased to 63% and 100% respectively. Thereafter, the radiographs demonstrated minimal change and maintained so-called 'radiological silence'. CONCLUSION: Osteointegration of fully HA-coated stems occurs in a predictable manner, and is noted in radiographs as early as the six-week follow-up period. Signs of osteointegration can be used as reliable indicators of solid femoral stem fixation after total hip replacement

Keywords : total hip replacement; hydroxyapatite; Corail; osteointegration.

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