Vol.:(0123456789) 1 3 Knee Surgery, Sports Traumatology, Arthroscopy https://doi.org/10.1007/s00167-018-5311-x KNEE Trochleoplasty provides good clinical outcomes and an acceptable complication profle in both short and long-term follow-up Laurie A. Hiemstra 1,2  · Devin Peterson 3  · Michael Youssef 5  · John Soliman 4  · Laura Banfeld 4  · Olufemi R. Ayeni 3 Received: 5 October 2018 / Accepted: 20 November 2018 © European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2018 Abstract Purpose The purpose of this study is to report on the global distribution and clinical outcomes of published articles related to trochleoplasty. Methods The online databases OVID Medline, OVID EMBASE, and the Cochrane Library were searched for the literature assessing trochleoplasty performed for lateral patellofemoral instability (LPI). Study data were abstracted looking at global trends in the literature, as well as clinical and patient-reported outcomes following this technique. Results For the assessment of global distribution, 29 studies including 998 patients met the inclusion criteria. The majority of the studies were conducted in Europe (93%) and most used an open thin fap technique (52%). For the secondary analysis of clinical outcomes, 21 studies were included with signifcant heterogeneity in patient selection, reporting on the degree of trochlear dysplasia, and patient-reported outcomes. All trochleoplasty techniques showed statistically signifcant improve- ment in clinical outcomes at average 50 months (range 3–228 months) post-operative, with most patients being satisfed with their procedure. Re-dislocation and complication rates were low. Conclusions European centers have published majority of data on trochleoplasty surgery, which has been shown to be an acceptable procedure for patients with high-grade trochlear dysplasia and LPI. Trochleoplasty has demonstrated good clinical outcomes, a low re-dislocation rate, and an acceptable complication profle in both short and long-term follow-up. This study highlights the difculty in reporting outcomes in this group of patients due to heterogeneity in patient selection, grading of trochlear dysplasia, and the lack of disease-specifc outcome measures. Level of evidence IV. Keywords Trochleoplasty · Trochlear dysplasia · Lateral patellar instability · Patella · Outcomes · Complications · Osteoarthritis · Medial patellofemoral ligament · MPFL Abbreviations LPI Lateral patellofemoral instability MPFL Medial patellofemoral ligament TTO Tibial tubercle osteotomy LR Lateral release PROM Patient-reported outcome measure OA Osteoarthritis Introduction Lateral patellofemoral instability (LPI) is a common knee injury. It is reported as the most common cause of trau- matic knee hemarthrosis in children [5, 54] and is commonly seen in young, active patients [20, 49]. The association of LPI with trochlear dysplasia has been well established with 65–85% of patients with patellofemoral instability demon- strating trochlear dysplasia compared to less than 10% of controls [16, 53]. In recent series reporting outcomes of medial patellofemoral ligament (MPFL) reconstruction for LPI, it has been reported that up to 92% of patients with * Laurie A. Hiemstra hiemstra@banfsportmed.ca 1 Banf Sport Medicine, Box 1300, Banf, AB T1L 1B3, Canada 2 Department of Surgery, University of Calgary, Calgary, AB, Canada 3 Division of Orthopaedic Surgery, Department Surgery, McMaster University, Hamilton, ON, Canada 4 Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada 5 Faculty of Medicine, University of Toronto, Toronto, ON, Canada