A comparative study of peri-prosthetic bone mineral density measurement using two different dual-energy X-ray absorptiometry systems.
24 patients aged 38-72 years with an uncemented total hip arthroplasty had dual-energy X-ray absorptiometry of the upper femur performed at a mean of 27 months after surgery. Each patient was scanned on both Lunar DPX and Hologic QDR-1000 densitometers. Peri-prosthetic bone mineral density (BMD) around the femoral component was measured in seven Gruen zones using software analysis techniques to allow quantification of bone mineral adjacent to a metal implant. There was a high correlation between the results obtained with the two systems (r = 0.94). BMD measurements using the Lunar DPX were 11% higher than with the Hologic QDR; however, there was a lack of agreement between the two instruments indicating that the two methods may not be used interchangeably.
Orthopaedic Research Unit, Addenbrooke's Hospital, Cambridge, UK.
B
B
Cohen
N
N
Rushton
D015502:Absorptiometry, Photon / Q000379:methods; D000328:Adult; D000368:Aged; D015519:Bone Density; D005260:Female; D005269:Femur / Q000737:chemistry*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D015203:Reproducibility of Results