Trochleoplasty in the Pediatric Population - A Systematic Review of Patient Characteristics, Treatment Strategies and Outcomes

BACKGROUND: Trochleoplasty is a treatment considered for patellofemoral instability patients with high grade dysplasia and those who have failed other surgical intervention. However, the indications for and the safety profile of this procedure remain unclear, particularly in the pediatric population where concerns exist regarding physeal arrest and the development of premature patellofemoral arthritis. PURPOSE: To systematically review the literature to evaluate trochleoplasty use, outcomes and complications observed among pediatric patients. METHODS: A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines reviewing Pubmed and SCOPUS databases. Inclusion criteria were studies including pediatric (<18yo) patients undergoing trochleoplasty with either a mean age <18 or those in which individualized patient characteristics and resultant outcomes were reported. Patient demographics, dysplasia type, procedure type and patient outcomes were abstracted when available and summarized with descriptive statistics. RESULTS: Our search strategy identified 4 studies published from 2016-2020 that included 86 patients (mean age=14.5yo) with a mean follow up of 31.6 months (range 12-60 months). All were classified as Level IV evidence. The majority (65%) of patients were Dejour B (56/86). A thin-flap technique was used in three studies while a lateral wedge augmentation procedure was utilized in the fourth. Kujala and Lysholm scores were collected in two studies with demonstrable patient improvement. The most common early complication noted was arthrofibrosis requiring arthroscopic lysis of adhesions (5 total patients). Only a single recurrent instability event was reported. In a single study, 4 of 23 patients had radiographic trochlear osteoarthritic changes at 5 years postoperatively. There were no reports of premature physeal arrest in two studies that monitored for this outcome. CONCLUSION: There remains a limited evidence base regarding trochleoplasty use in pediatric patients. Overall, favorable outcomes have been observed with infrequent recurrent instability. There are no reports of growth disturbance from physeal arrest as a result of this procedure identified, but reporting among patients with confirmed skeletal immaturity is scarce. Patellofemoral arthritic changes were observed radiographically in a small subgroup of patients, but further work is necessary to determine if this is a result of the procedure itself or the underlying pathology being treated. As interest grows in implementing trochleoplasty in the pediatric population and potentially skeletally immature individuals, improved evidence is necessary to determine the incidence of major complications in order to better define the safety profile and indications for use in children and adolescents.