Open and arthroscopic deepening trochleoplasty improves post-operative outcomes: A systematic review of the literature reveals lack of comparability between techniques

PurposeDeepening trochleoplasty improves outcomes in patients with trochlear dysplasia. The aim of this systematic review was to present the outcomes after open thin-flap, open thick-flap and arthroscopic deepening trochleoplasty.MethodsA systematic review was conducted using the PRISMA guidelines. Literature was searched in the PubMed, EMBASE and Cochrane databases on 16 December 2024. All studies from the inception of the databases to the date of the search were included in the search. Studies were included if they examined patients with patellar instability and trochlear dysplasia treated with either open or arthroscopic deepening trochleoplasty and reported pre- and post-operative outcomes. Two independent reviewers screened titles and abstracts, reviewed the full text and performed the quality assessment.ResultsA total of 32 studies, consisting of 1435 trochleoplasty cases in 1310 patients, were included. Of the included studies, 21 concerned open thin-flap trochleoplasty, 8 concerned open thick-flap trochleoplasty and 3 concerned arthroscopic trochleoplasty. The most used patient-reported outcome measures were the Kujala score, International Knee Documentation Committee score, visual analogue scale pain score, Lysholm Knee Score and Tegner Activity Scale; and the most reported radiological outcome measures were trochlear sulcus angle, trochlear bump, trochlear depth, tibial tubercle-trochlear groove distance, Caton-Deschamps index and patellar tilt. All three trochleoplasty techniques lead to improvements in post-operative outcome measures.ConclusionDeepening trochleoplasty improves post-operative outcome using both open thin-flap, open thick-flap and arthroscopic deepening technique. Comparison between the techniques is challenging due to low methodological quality of studies. Further research is needed to document treatment effect and improve patient outcome.Level of EvidenceLevel IV.