Anatomic physeal-sparing MPFL reconstruction in skeletally immature patients shows favourable outcomes at a minimum of 24-month follow-up

Abstract

Purpose

Recurrent patellar dislocation is a prevalent orthopaedic issue among active paediatric and adolescent populations. Bony surgical procedures are not recommended in growing patients; therefore, the focus of surgery is on restoring the medial patellar ligaments, with different reconstructive techniques available. This retrospective case series focuses on the 2-year outcomes of medial patellofemoral ligament (MPFL) reconstruction in skeletally immature patients with open physis.

Methods

Twenty-four consecutive patients with patellofemoral instability and open growth plates underwent anatomic MPFL reconstruction with a physeal-sparing technique. All subjects have had more than three episodes of true patellar dislocations. Preoperative radiographic examination included anteroposterior and lateral views to assess patella alta and limb alignment. Magnetic resonance imaging was performed to evaluate trochlear dysplasia and tibial tubercle–trochlear groove (TT–TG) distance. The patients were questioned regarding complications and clinical outcomes using the visual analogue scale (VAS), Kujala and Paediatric International Knee Documentation Committee (Pedi-IKDC) score. Variables were evaluated using paired t test with significance at p < 0.05.

Results

The mean age at the time of operation was 13.04 years (9–16 years). The cohort was followed for a mean duration of 38.66 months (24–86 months). The mean time from injury to surgery was 50.45 days (16–80 days). No growth arrest, limb-length discrepancies or angular deformities were observed post-operatively during the whole follow-up period. No patellar re-dislocations were recorded throughout the study period. The VAS score improved significantly from 5.67 (4–8) to 1.88 (0–4) (p < 0.01). The Kujala score improved significantly from 64.67 (44–81) preoperatively to 87.58 (77–100) post-operatively (p < 0.01). The Pedi-IKDC also increased significantly from 58.81 (34.80–77.70) preoperatively to 90.64 (70.70–100) post-operatively (p < 0.01). The vast majority of patients (87.5%) returned to their pre-injury activity level. Boys scored better than girls in VAS, Pedi-IKDC and Kujala score post-operatively, but these differences were not statistically significant.

Conclusion

Physeal-sparing MPFL reconstruction in children and adolescents yields excellent midterm results and allows patients to return to sports without redislocation of the patella. Boys scored better than girls in VAS, Pedi-IKDC and Kujala score post-operatively, but these differences were not statistically significant.

Level of Evidence

IV: case series with no comparative group.