title: Predictors of outcome after manipulation under anaesthesia in patients with a stiff total knee arthroplasty.
abstract: OBJECTIVE
  Flexion in a stiff total knee arthroplasty (TKA) can be improved by manipulation under anaesthesia (MUA). Although this intervention usually results in an improvement in range of motion, the expected result is not always achieved. The purpose of this study is to determine which factors affect range of motion after manipulation in patients with a stiff total knee.
  
  
  METHODS
  After exclusion (n = 22), the data of 158 patients (138 knees) with a stiff knee after TKA who received a manipulation under anaesthesia between 2004 and 2014 were retrospectively analysed. Pre-, peri- and post-operative variables were identified and examined for their influence on flexion after the manipulation using Kruskal-Wallis and Mann-Whitney U tests and Spearman correlations.
  
  
  RESULTS
  After MUA, a mean improvement in flexion of 30.3° was observed at the final follow-up. Preoperative TKA flexion, design of TKA and interval between TKA procedure and MUA were positive associated with an increase in flexion after MUA. MUA performed 12 weeks or more after TKA procedure deteriorated the outcome.
  
  
  CONCLUSIONS
  Three factors, pre-TKA flexion type of prosthesis and interval between TKA procedure and manipulation under anaesthesia, were found to have impact on flexion after TKA and MUA were identified. Results are expected to be inferior in patients with low flexion before TKA procedure or with a long interval (>12 weeks) between the TKA procedure and the manipulation under anaesthesia.
  
  
  METHODS
  IV.
authors.affiliation: Department of Orthopaedics, University Hospitals Leuven, B-3000, Louvain, Belgium. luc.vanlommel@gmail.com.
authors.forename: L
authors.identifier: http://orcid.org/0000-0001-6462-8196
authors.initials: L
authors.lastname: Vanlommel
authors.affiliation: Department of Orthopaedics, University Hospitals Leuven, B-3000, Louvain, Belgium.
authors.forename: T
authors.initials: T
authors.lastname: Luyckx
authors.affiliation: Department of Orthopaedics, University Hospitals Leuven, B-3000, Louvain, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: Vercruysse
authors.affiliation: Department of Orthopaedics, Hospital Genk, UHASSELT - University of Hasselt, B-3600, Genk, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Bellemans
authors.affiliation: Department of Orthopaedics, University Hospitals Leuven, B-3000, Louvain, Belgium.|Department of Development and Regeneration, KU Leuven - University of Leuven, Louvain, Belgium.
authors.forename: H
authors.initials: H
authors.lastname: Vandenneucker
mesh_terms: D000368:Aged; D000767:Anesthesia, Epidural; D000768:Anesthesia, General; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology* / Q000601:surgery; D008297:Male; D008349:Manipulation, Orthopedic / Q000379:methods*; D008875:Middle Aged; D011183:Postoperative Complications / Q000628:therapy*; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013997:Time Factors
keywords: Arthrofibrosis; Flexion; Mobilization under anaesthesia; Stiffness; Total knee arthroplasty