Peri-prosthetic bone mineral density after total knee arthroplasty. Cemented versus cementless fixation

J Bone Joint Surg Br. 2006 May;88(5):606-13. doi: 10.1302/0301-620X.88B5.16893.

Abstract

We compared peri-prosthetic bone mineral density between identical cemented and cementless LCS rotating platform total knee arthroplasties. Two matched cohorts had dual energy x-ray absorptiometry scans two years post-operatively using a modified validated densitometric analysis protocol, to assess peri-prosthetic bone mineral density. The knee that was not operated on was also scanned to enable the calculation of a relative bone mineral density difference. Oxford Knee and American Knee Society scores were comparable in the two cohorts. Statistical analysis revealed no significant difference in absolute, or relative peri-prosthetic bone mineral density with respect to the method of fixation. However, the femoral peri-prosthetic bone mineral density and relative bone mineral density difference were significantly decreased, irrespective of the method of fixation, particularly in the anterior distal portion of the femur, with a mean reduction in relative bone mineral density difference of 27%. There was no difference in clinical outcome between the cemented and cementless LCS total knee arthroplasty. However, both produce stress-shielding around the femoral implants. This leads us to question the use of more expensive cementless total knee components.

MeSH terms

  • Absorptiometry, Photon / methods
  • Aged
  • Aged, 80 and over
  • Arthroplasty, Replacement, Knee*
  • Bone Cements
  • Bone Density / physiology*
  • Bone Diseases, Metabolic / physiopathology
  • Cementation
  • Female
  • Femur / physiopathology
  • Femur Neck / physiopathology
  • Humans
  • Knee Prosthesis
  • Lumbar Vertebrae / physiopathology
  • Male
  • Middle Aged
  • Osteoporosis / physiopathology
  • Sex Factors
  • Treatment Outcome

Substances

  • Bone Cements