Abstract
Introduction
The aim of the study was to whether the bone grafting techniques used affected the long term stability of the acetabular implant.
Methods
41 patients treated with a cemented total hip replacement with pre-operative protrusio or central acetabular defects at surgery were identified. The severity of initial protrusio was determined on plain AP pelvis radiographs by measuring the distance of the medial acetabular wall from the ilio-ischial line. The post-operative and last follow-up x-rays were reviewed, the thickness of the medial wall and the centre-edge angle of the cup was measured.
Results
The most common indication was osteoarthritis (34 patients, 83%). The mean age at surgery was 64 years (range = 39-89 years) and 30 patients (73%) were determined to have an incompetent medial wall at surgery. The mean follow-up was 6.5 years (range = 1-22 years). The mean penetration of the medial wall was 6.5mm (range 1-18mm) with a CE angle of 69°. There were significant improvements in the medial wall thickness to a mean of 16mm, with a mean CE angle of 50° (p<0.0001) post-operatively. This was maintained in the long term with no significant difference at final follow-up of either medial wall thickness (p=0.31) or CE angle (p=0.71). The medial wall showed radiographic signs of remodelling at final x-ray in 88% of patients.
Conclusion
Bone grafting to the acetabulum is a satisfactory method of treatment for protrusio and central defects in the long term, without significant movement of the acetabular components.
