title: The inhibitory effect of alendronate-hydroxyapatite composite coating on wear debris-induced peri-implant high bone turnover.
abstract: BACKGROUND
  Bisphosphonate (BP) has been confirmed as the most potent drug for enhancing implant stability. There have been few studies focused on BP-hydroxyapatite (HA) composite coatings, and the mechanisms through which BPs inhibit wear debris-induced high bone turnover have not been comprehensively discussed.
  
  
  METHODS
  Thirty rabbits were divided into three groups. HA-coated implants were inserted into the proximal region of the medullary cavity of the left tibia. In groups II and III, particles were injected around the implant and into the knee joint during implantation. Low-dose alendronate (ALN) was combined with the HA coating in group III. The efficacy of the composite coating was evaluated using several parameters, including the intra-articular pressure, histology of the synovial membranes and bone-implant interfaces, bone histomorphometry and mineralization, implant stability, osteolysis-related cytokine levels, and the duration of ALN release in vitro.
  
  
  RESULTS
  The results indicate that the ALN-HA composite coating reduces peri-implant high bone turnover; improves bone-implant integration, bone quality, and implant stability; and inhibits particle migration. In vitro results suggest that the ALN-HA composite coating can afford long release duration.
  
  
  CONCLUSIONS
  This study may help us further realize the mechanisms through which BPs enhance bone-implant integration in a state of peri-implant high bone turnover. BP-HA composite coatings are promising materials, particularly in revision surgeries.
authors.affiliation: Department of Orthopaedics, Xi Jing Hospital, The Fourth Military Medical University, ChangLe West Road 15#, Xi'an, Shaanxi, 710032, China.
authors.forename: Shun
authors.initials: S
authors.lastname: Niu
authors.forename: Xiaorui
authors.initials: X
authors.lastname: Cao
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Qingsheng
authors.initials: Q
authors.lastname: Zhu
authors.forename: Jinyu
authors.initials: J
authors.lastname: Zhu
mesh_terms: D019386:Alendronate / Q000627:therapeutic use*; D000818:Animals; D015519:Bone Density / Q000502:physiology; D016207:Cytokines / Q000378:metabolism; D017886:Durapatite / Q000627:therapeutic use*; D008297:Male; D023421:Models, Animal; D009985:Orthopedics; D010014:Osteolysis / Q000378:metabolism; D019736:Prostheses and Implants; D011817:Rabbits; D013583:Synovial Membrane / Q000473:pathology; D013977:Tibia / Q000378:metabolism* / Q000601:surgery*
chemical_list: D016207:Cytokines; D017886:Durapatite; D019386:Alendronate