title: Novel unidirectional porous hydroxyapatite used as a bone substitute for open wedge high tibial osteotomy.
abstract: OBJECTIVE
  The purpose of this study was to clinically and radiologically evaluate the availability, osteoconductivity, and resorption of a novel unidirectional porous hydroxyapatite (UDPHAp) used as an artificial substitute for open wedge high tibial osteotomy (OWHTO). Our hypothesis was that UDPHAp is a safe and useful bone substitute for OWHTO.
  
  
  METHODS
  Seven patients (2 men and 5 women aged 34-72years) who underwent OWHTO and were followed up for more than 12months were retrospectively studied. After the osteotomy, the gap created was filled with UDPHAp(REGENOS® Kuraray Co.Ltd). Radiography and computed tomography(CT) were performed, and gap healing was assessed postoperatively. The Japanese Orthopaedic Association (JOA) knee score was determined pre- and post-operatively for clinical evaluation.
  
  
  RESULTS
  Neither gross displacement nor collapse of the UDPHAp block graft was observed within 12 months after surgery. Both radiographs and CT showed attenuation of lucency and increasing sclerosis over time. JOA score improved from 71.2 (65-80) to 95.8 (85-100).
  
  
  CONCLUSIONS
  Short term results for OWHTO using UDPHAp was satisfactory. Clinical improvement of JOA scores were seen, besides osteogenesis was progressing in and around the artificial bone grafts.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai Tsukuba, Ibaraki, 305-8575, Japan, sakane-m@tsukuba-seikei.jp.
authors.forename: Kenta
authors.initials: K
authors.lastname: Uemura
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kanamori
authors.forename: Katsuya
authors.initials: K
authors.lastname: Aoto
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Masataka
authors.initials: M
authors.lastname: Sakane
mesh_terms: D000328:Adult; D000368:Aged; D018786:Bone Substitutes / Q000627:therapeutic use*; D017886:Durapatite / Q000138:chemical synthesis* / Q000627:therapeutic use*; D005260:Female; D049690:History, Ancient; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000628:therapy*; D010027:Osteotomy; D016062:Porosity; D011859:Radiography; D013977:Tibia / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D018786:Bone Substitutes; D017886:Durapatite