The location of medial patellofemoral ligament injury in adolescents and children.

BACKGROUND

The location of medial patellofemoral ligament (MPFL) tears has been well documented in the adult population, with most occurring at the insertion of the ligament on the adductor tubercle. It is not clear whether a difference exists in the pediatric and adolescent populations. The location of the injury has implications for treatment recommendations and planning surgical approaches. The purpose of this study is to determine whether the location of MPFL injury differs among the adult and younger populations. Our hypothesis is that the location of MPFL tears in adolescents and children is not predominantly at the adductor tubercle.

METHOD: At our institution, we retrospectively reviewed 113 children aged 5 to 17, who were surgically treated for a patellar dislocation. All patients had confirmation of a patellar dislocation or severe subluxation. Imaging studies, clinic notes, and operative notes were used to determine the location of the MPFL injury.

RESULTS

Proportion of MPFL injuries found intraoperatively at the adductor tubercle was larger than 0.5 (z test=2.97). Percentage of MPFL tears at the adductor tubercle was 73% of the cases studied.

CONCLUSIONS

The location of MPFL injuries found intraoperatively at the adductor tubercle was 73% in our series. This is slightly lower than MPFL tear location in the adult population, which has been reported to be between 80% and 100%. Our hypothesis that the location of MPFL tears in adolescents and children is not predominantly at the adductor tubercle was proven false. This study has clinical applications for treatment recommendations and planning surgical approaches for the pediatric patient with a tear of the MPFL.

LEVEL OF EVIDENCE: Level II-prognostic.