Abstract
INTRODUCTION:
Cementless total hip arthroplasty (THA) is gaining ground over cemented THA. The objective of this study was to assess survival rates of a ceramic on polyethylene THA implant after at least 3 years and to assess changes in acetabular bone structure.
MATERIAL AND METHODS:
Twenty five ceramic-on-polyethylene THA prostheses were implanted between 2010 and 2013. Mean age at the time of operation was 57.9 years. Clinical outcomes were assessed using the Harris hip score and Postel Merle d'Aubigné score. For each hip, radiographs were examined for acetabular radiolucent lines, changes in bone structure and trabeculae were assessed comparatively to the other hip and classified from no change to severe osteolysis. Changes in trabeculae served to assess the loads applied to the bone. Polyethylene wear was assessed using the Livermore method.
RESULTS:
A single patient was lost to follow-up. At last follow-up, 16 patients had died and six were contacted and had not required revision surgery; the remaining 52 patients (59 THAs) were re-evaluated and none had evidence of loosening. The Harris hip score at last evaluation was 91.6 compared to 60.5 preoperatively. No hips had evidence of acetabular osteolysis. For two hips, the radiographs showed complete acetabular radiolucent lines less than 2 mm in width, with no mobilisation. Trabecular distribution was homogeneous with no stress shielding. Mean annual rate of wear was 0.08 mm. No instances of femoral component loosening were recorded
DISCUSSION:
This study confirms the reliability of ceramic on poly THA, with a 3-year survival rate of 98.3%, in keeping with earlier data. Thus, our results establish that ceramic-on-polyethylene prostheses remain valid options for THA.
