Bone remodelling around a cemented polyethylene cup. A longitudinal densitometry study

• Published in: Journal of bone and joint surgery. British volume Vol. 88; no. 4; pp. 455 - 459
• Main Authors: Shetty, N R, Hamer, A J, Kerry, R M, Stockley, I, Eastell, R, Wilkinson, J M
• Format: Journal Article
• Language: English
• Published: England British Editorial Society of Bone & Joint Surgery 01.04.2006
• Edition: British volume
• Subjects: Absorptiometry, Photon - methods; Acetabulum - physiopathology; Acetabulum - surgery; Aged; Analysis of Variance; Bone Density - physiology; Bone Remodeling - physiology; Female; Femur - physiopathology; Femur - surgery; Hip Joint - surgery; Hip Prosthesis; Humans; Longitudinal Studies; Male; Osteoarthritis, Hip - physiopathology; Osteoarthritis, Hip - surgery; Polyethylene; Prosthesis Design; Reproducibility of Results
• ISSN: 0301-620X; 2049-4394; 2044-5377; 2049-4408
• DOI: 10.1302/0301-620x.88B4.16786

The aims of this study were to examine the repeatability of measurements of bone mineral density (BMD) around a cemented polyethylene Charnley acetabular component using dual-energy x-ray absorptiometry and to determine the longitudinal pattern of change in BMD during the first 24 months after surgery. The precision of measurements of BMD in 19 subjects ranged from 7.7% to 10.8% between regions, using a four-region-of-interest model. A longitudinal study of 27 patients demonstrated a transient decrease in net pelvic BMD during the first 12 months, which recovered to baseline at 24 months. The BMD in the region medial to the dome of the component reduced by between 7% and 10% during the first three months, but recovered to approximately baseline values by two years. Changes in BMD in the pelvis around cemented acetabular components may be measured using dual-energy x-ray absorptiometry. Bone loss after insertion of a cemented Charnley acetabular component is small, transient and occurs mainly at the medial wall of the acetabulum. After two years, bone mass returns to baseline values, with a pattern suggesting a uniform transmission of load to the acetabulum.