Jordy van Sambeeck

Chapter 9 152 Chapter 7 presents the results of a systematic reviewof literature andmeta-analysis to assess the rate of complications after various techniques used for trochleoplasty. The search strategy retrieved 1,848 unique records. The subsequent selection procedure resulted in 20 studies which could be included in the systematic review. These studies included 822 trochlear osteotomy procedures in 739 patients with an average age of 22.6 years. A total of 190 complications occurred including recurrent instability, loss of knee range of motion, development or progression of PF OA and return to the operating room. Meta-analysis was performed for the following complications: recurrence of patellar instability, recurrent dislocation, patellofemoral osteoarthritis and further surgery for Bereiter- and Dejour-type trochleoplasty procedures. The Bereiter and Dejour trochleoplasties showed complication rates similar to other patellar stabilizing procedures. The proportions of reoperation were 0.08 and 0.20 respectively. Decreased range of motion and recurrence of instability were the two most frequent reasons for further surgery. The proportion of redislocation was 0.04 and 0.02 respectively, which is relatively low. The results of this study indicate that these two trochleoplasty techniques successfully prevent recurrent dislocation and/or instability and have a rate of complications similar to other patellar stabilizing procedures. Almost all studies included in this systematic review and meta-analysis were retrospective or prospective case series. None of the studies were randomized or were comparative studies. Therefore, no conclusion can be drawn as to whether one of the techniques of trochleoplasty is superior to the other in terms of rate of complications. Surgical treatment of patients with recurrent patellar instability is still a challenging and controversial subject. The corner stone of surgical treatment is reconstruction of the MPFL. Results of the studies presented in Chapter 3-7 indicate that both a tibial tubercle osteotomy (TTO) and a trochleoplasty can be a safe part of the surgical treatment plan. However, based on our studies no conclusions can be drawn on when to perform which type of osteotomy with how much correction. Rood et al. 8 , proposed an algorithm inwhich a trochleoplasty is indicated in patients with high grade trochlear dysplasia and a TTO is indicated in case of patella alta or excessive lateralization. However, there is still a need for improvement of (and more nuance on) indication of these type of osteotomies. Outcome measurement Research questions: 1. Are the translated Banff Patellar Instability Instrument and Norwich Patellar Instability score valid patient reported outcome measurements? (Chapter 8)