title: Preoperative Periarticular Knee Bone Mineral Density in Osteoarthritic Patients Undergoing TKA.
abstract: BACKGROUND
  Preoperative periarticular bone quality is affected by joint loading. The purpose of this study was to determine the periarticular bone mineral density of the knee joint of patients undergoing total knee arthroplasty, and whether the location of the load-bearing axis correlates with the measured bone mineral density.
  
  
  METHODS
  The bone mineral densities of the medial and lateral femoral condyles and the medial and lateral tibial condyles were analyzed in consecutive 116 osteoarthritic patients (130 knees) by dual energy x-ray absorptiometry.
  
  
  RESULTS
  The median bone mineral density values in the condyles were 1.138 in femoral medial, 0.767 in femoral lateral, 1.056 in tibial medial, and 0.714 in tibial lateral. The medial condyles showed significantly higher bone mineral densities than the lateral condyles in both the femur and tibia. In addition, the femoral medial showed significantly higher bone mineral density levels than the tibial medial, and the femoral lateral condyle had higher bone mineral density levels than the tibial lateral. The bone mineral density Medial/Lateral ratio was significantly negatively correlated with the location (tibial medial edge 0%, lateral edge 100%) of the load-bearing axis in the femur and tibia.
  
  
  CONCLUSIONS
  Preoperative bone mineral density values may provide against the changes in bone mineral density after total knee arthroplasty by reflecting the correlation with joint loading axis. These results help explain why total knee arthroplasty has such good long-term clinical outcomes with a low frequency of component loosening and periarticular fractures despite a high degree of postoperative bone loss.
authors: Ishii Orthopaedic and Rehabilitation Clinic, Saitama, Japan.
authors: Yoshinori
authors: Y
authors: Ishii
authors: Ishii Orthopaedic and Rehabilitation Clinic, Saitama, Japan.
authors: Hideo
authors: H
authors: Noguchi
authors: Ishii Orthopaedic and Rehabilitation Clinic, Saitama, Japan.
authors: Junko
authors: J
authors: Sato
authors: Ishii Orthopaedic and Rehabilitation Clinic, Saitama, Japan.
authors: Koji
authors: K
authors: Todoroki
authors: Ishii Orthopaedic and Rehabilitation Clinic, Saitama, Japan.
authors: Nobukazu
authors: N
authors: Ezawa
authors: Department of Medical Informatics, Niigata University Medical and Dental Hospital, Niigata, Japan.
authors: Shin-Ichi
authors: S
authors: Toyabe
keywords: Dual energy x-ray absorptiometry; Knee; Load-bearing axis; Osteoarthritis; Preoperative bone mineral density; Total knee arthroplasty