Summary

Patients who underwent medial patellofemoral ligament reconstruction reported significantly lower preoperative athletic activity levels and fewer sports injuries than age- and sex-matched ACL reconstruction patients.

Abstract

Background

Patellar dislocations can result from injury mechanisms that are similar to anterior cruciate ligament (ACL) tears and can happen during athletic participation as well as during activities of daily living. While there is a growing body of evidence describing the epidemiology and injury prevention methods for athletes with ACL injuries, there are few studies that describe baseline activity characteristics of patients with patellar dislocations. This study aimed to investigate baseline activity levels, mechanism of injury, and patient reported outcomes of adolescent patients who underwent a medial patellofemoral ligament reconstruction (MPFLR) and to compare this group to age- and sex-matched patients who underwent an ACL reconstruction (ACLR).

Methods

Patients who underwent an MPFLR or ACLR by one of two fellowship-trained pediatric orthopedic sports medicine surgeons at a single institution between 2016 and 2023 were reviewed. Patients were excluded if they did not have preoperative patient reported outcomes completed within three months before surgery, or if they were syndromic patellofemoral dislocators. Patient characteristics including age, sex, mechanism of injury, and sports participation were recorded. Patient-reported outcome measures including the Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS), Pediatric International Knee Documentation Committee (Pedi-IKDC), Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference, and PROMIS Mobility were collected.. MPFLR participants were age and sex-matched to ACLR participants with surgical dates within 1 year.

Results

A total of 912 patients were identified and 540 patients met the final inclusion and exclusion criteria. A total of 228 MPFLR participants were successfully age- and sex-matched to 228 ACLR participants. The mean age of the cohort was 14.8 ± 2.1 years and 53% were female. 61% of the MPFLR cohort sustained their injury during an organized sport, whereas 94% of the ACLR cohort sustained their injury during an organized sport (p < 0.001). The most common sports played at the time of injury for MPFLR patients were basketball, soccer, football, and dance, while ACLR patients were most commonly injured during soccer, football, and basketball. Dance was identified as the second most common sport at time of injury for females in the MPFLR group, while only one female patient sustained an ACL injury during dance class. The MPFLR group had a significantly lower HSS Pedi-FABS score than the ACLR group (MPFLR: median = 16.0 vs. ACLR: median = 23.0, p < 0.001).

Conclusions

This study found that among adolescent individuals, organized sports injuries accounted for 61% of patellar dislocations and 94% of ACL tears. The MPFLR group reported significantly lower preoperative athletic activity levels compared to the ACLR group. Dance was identified as the second most common sport at the time of patellar dislocation injury in females. This finding warrants further investigation into injury prevention strategies for females participating in dance.