title: Posterior Cruciate Ligament Retention or Substitution During Total Knee Arthroplasty Does Not Affect Long-Term Bone Mineral Density or Quality.
abstract: Physical activity is recognized as one of the factors that influence bone mineral density (BMD) and bone quality after total knee arthroplasty (TKA). According to biomechanical analyses after posterior cruciate ligament (PCL) retaining (PCLR) and substituting (PCLS) TKA, each implant design has different kinematics and kinetics. The purposes of this study were: (1) to perform within-patient comparisons of the midterm and long-term effects of PCL retention in mobile-bearing TKA on proximal femur and tibia BMD and calcaneus bone quality measured using ultrasound and (2) to identify correlations between them.
  
  
  
  A prospective, quasi-randomized design was used. Thirty-seven patients (74 knees) who underwent bilateral TKA (PCLR on one side and PCLS on the other) were evaluated. Mean follow-up periods were 118 months (standard deviation 40) and 117 months (standard deviation 36) in knees with PCLR and PCLS implants, respectively. The BMDs of the total hip and proximal tibia and broadband ultrasound attenuation (BUA; dB/MHz) through the calcaneus were measured.
  
  
  
  The mean BMD of PCLR and PCLS were equivalent at the proximal hip and tibia. The BUA of the calcaneus was also the same between implants. There were significant correlations between the 3 anatomic sites.
  
  
  
  When measured approximately 10 years after TKA, PCL retention had no substantial effect on the BMD of the proximal femur and tibia, or on the bone quality of the calcaneus. The measurement of noninvasive BUA may predict BMD, although further analysis is required.
authors.affiliation: Ishii Orthopaedic and Rehabilitation Clinic, Gyoda, Saitama, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ishii
authors.affiliation: Ishii Orthopaedic and Rehabilitation Clinic, Gyoda, Saitama, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Noguchi
authors.affiliation: Ishii Orthopaedic and Rehabilitation Clinic, Gyoda, Saitama, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Sato
authors.affiliation: Ishii Orthopaedic and Rehabilitation Clinic, Gyoda, Saitama, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Todoroki
authors.affiliation: Division of Information Science and Biostatistics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Toyabe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D015519:Bone Density; D002111:Calcaneus / Q000000981:diagnostic imaging; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000601:surgery; D008297:Male; D020370:Osteoarthritis, Knee / Q000601:surgery*; D016119:Posterior Cruciate Ligament / Q000000981:diagnostic imaging / Q000601:surgery*; D011446:Prospective Studies; D011474:Prosthesis Design; D016032:Randomized Controlled Trials as Topic; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery; D014463:Ultrasonography
keywords: PCL-retaining TKA; PCL-substituting TKA; bilateral TKA; bone mineral density; bone quality; broadband ultrasound attenuation