title: Cruciate retaining versus posterior stabilized total knee arthroplasty after previous high tibial osteotomy.
abstract: OBJECTIVE
  This study aimed to investigate the clinical outcome of total knee arthroplasty (TKA) after previous high tibial osteotomy (HTO) using cruciate retaining (CR) versus posterior stabilized (PS) prostheses.
  
  
  METHODS
  Between 2001 and 2010, 133 patients who underwent TKA after previous HTO were included in this study and prospectively followed up for two years. Two independent assessors recorded the range of motion of the operated knee, anterior-posterior (AP) laxity, medial-lateral (ML) laxity, Oxford Knee Score (OKS), Knee Society Function Score (KSFS) and Knee Society Knee Score (KSKS).
  
  
  RESULTS
  Thirty-three patients received CR prostheses, while 100 patients received PS prostheses. The median (inter-quartile range) knee flexion at 6 months and 2 years post-TKA was 101° (90, 116) and 110° (90, 118), respectively for the CR group, compared to 115° (100, 121) and 118° (108, 125) for the PS group (p = 0.010 and p = 0.009, respectively). AP and ML laxities were comparable in both groups of patients. While both groups of patients showed improvement in OKS, KSFS and KSKS at 6 months and 2 years post-TKA, there was no significant difference in these clinical scores between the two groups at both time points of follow-up. None of the 133 patients required revision surgery.
  
  
  CONCLUSIONS
  Although PS prostheses offer better knee flexion in TKA after previous HTO, the knee stability, clinical scores and revision rate at 6 months and 2 years post-TKA are comparable between CR and PS prostheses. The authors conclude that CR is an alternative to PS prostheses in patients undergoing TKA after previous HTO.
  
  
  METHODS
  III.
authors.affiliation: Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore. yqjchen@gmail.com.
authors.forename: Jerry Yongqiang
authors.initials: JY
authors.lastname: Chen
authors.affiliation: Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore.
authors.forename: Ngai Nung
authors.initials: NN
authors.lastname: Lo
authors.affiliation: Department of Physiotherapy, Singapore General Hospital, Singapore, Singapore.
authors.forename: Hwei Chi
authors.initials: HC
authors.lastname: Chong
authors.affiliation: Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore.
authors.forename: Hee Nee
authors.initials: HN
authors.lastname: Pang
authors.affiliation: Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore.
authors.forename: Darren Keng Jin
authors.initials: DK
authors.lastname: Tay
authors.affiliation: Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore.
authors.forename: Pak Lin
authors.initials: PL
authors.lastname: Chin
authors.affiliation: Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore.
authors.forename: Shi-Lu
authors.initials: SL
authors.lastname: Chia
authors.affiliation: Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore.
authors.forename: Seng Jin
authors.initials: SJ
authors.lastname: Yeo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000502:physiology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010027:Osteotomy; D016119:Posterior Cruciate Ligament / Q000601:surgery*; D016059:Range of Motion, Articular; D012086:Reoperation; D013977:Tibia / Q000601:surgery*
keywords: Cruciate retaining; High tibial osteotomy; Posterior stabilized; Total knee arthroplasty