Jordy van Sambeeck

Chapter 7 104 Materials and methods A systematic review was conducted and reported in accordance with the reporting guidance provided in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement 12 . The protocol was prospectively registered in PROSPERO (https://www.crd.york.ac.uk/PROSPERO/display_record. asp?ID=CRD42015029815). Search MEDLINE, EMBASE, Web of Science and Cochrane Library databases were searched (last search performed 10 May 2016). The search strategy was determined in collaboration with an information specialist from the medical library of the Radboud University medical center. Keywords used to develop our search strategy were ‘patellar instability’, ‘trochleoplasty’, and ‘complications’. The detailed search strategy is provided in the Appendix. Reference lists of included studies and relevant reviews were screened for relevant studies. No Grey literature search was undertaken. Eligibility & Study selection All articles were screened based on title and abstract by 2 reviewers (JvS, SvdG). In this screening stage, studies were excluded if they fulfilled 1 of the following criteria: 1) no trochleoplasty performed; 2) no clinical outcome study on humans (observational and/or experimental) or description of operative technique; 3) animal study, case report, review article, cadaveric study, in vitro study, biomechanical study or conference proceeding; 4) article not in English, Dutch, French, or German (all languages were screened); 5) article published before 1990. In the subsequent full text screening stage studies were further evaluated for eligibility. Studies were excluded if they met any of criteria 1-5 or 1 of the following: 6) no report of complications; 7) indication for trochleoplasty was not recurrent patellar instability. In addition, studies were excluded if they contained data also published in another included paper. In case of a study being part of a larger, original study, the original study was included. In case of reported preliminary data the most extended paper was included in the analysis. Discrepancies between the reviewers were resolved by discussion and consensus. The primary outcome was the rate of complications of trochleoplasty procedures. Complications were defined as: a negative outcome including returning to the operating room (OR), symptomatic hardware, loss of range of motion (ROM), increased pain/apprehension leading to return to the OR, patella redislocation/ subluxation/instability, accelerated (radiological) progression of patellofemoral osteoarthritis (PF OA), deep venous thrombosis (DVT), infection, distal femoral fracture. Complications were subdivided in minor or major complications. Minor complications included complaints of recurrence of maltracking or subluxation,