Clinical outcomes of combined MPFL-reconstruction with MPTL-augmenting patellar distalization using hamstring autograft versus isolated MPFL in adolescents with patella alta: a retrospective comparative study.

backgroundPatella alta is a major risk factor for recurrent patellar dislocation in adolescents. This study aimed to compare the clinical outcomes of isolated medial patellofemoral ligament (MPFL) reconstruction with those of MPFL reconstruction augmented by medial patellotibial ligament (MPTL)-distalization, both using a semitendinosus hamstring autograft, in adolescent patients with patella alta.

methodsA retrospective cohort study was conducted on 28 adolescent patients (mean age 11.2 ± 1.6 years; 9 males, 19 females) treated for recurrent patellar dislocation between May 2020 and July 2025. All patients had patella alta (Caton-Deschamps index > 1.2) and a history of at least one dislocation, with varying degrees of trochlear dysplasia (Dejour types A-B). All patients underwent MPFL reconstruction using a semitendinosus hamstring autograft harvested with preservation of its native distal tibial insertion, fixed via a single oblique transpatellar tunnel and femoral interference-screw fixation proximal to the distal femoral physis. Group A (n=14) underwent isolated MPFL reconstruction. Group B (n=14) underwent the same MPFL reconstruction with an additional MPTL-augmenting patellar distalization step using the same graft, secured by trans-osseous periosteal suture at the lateral patella. Surgical techniques emphasized physeal spare during reconstruction. Preoperative and postoperative assessments included the Kujala score, Lysholm score, Caton-Deschamps index, and sulcus angle. Follow-up averaged 12- 24 months. CT was performed using a low-dose pediatric protocol specifically for TT-TG measurement and trochlear bony morphology; MRI was used for soft-tissue and cartilage assessment. Group assignment was not randomized; patients with more pronounced patella alta and higher-grade clinical instability were preferentially treated with the combined procedure.

resultsBoth groups showed significant improvements in functional scores. In Group (A), Kujala scores improved from 59.3 ± 8.3 to 84.3 ± 5.1, and Lysholm scores from 50.3 ± 7.5 to 74.7 ± 9.3. Caton-Deschamps index decreased from 1.27 to 1.20. In Group (B), Kujala scores improved from 56.2 ± 7.4 to 88.9 ± 4.5, and Lysholm scores from 51.4 ± 7.6 to 87.4 ± 6.2. Caton-Deschamps index decreased from 1.28 to 1.11, indicating better patellar height correction. Complications occurred in 36% of Group A and 21% of Group B. Recurrent instability occurred in 2 patients (14%) in Group A and 1 patient (7%) in Group B; all were subluxation episodes managed non-operatively, and no revision surgery was required.

conclusionsThis study demonstrated that MPFL reconstruction with MPTL-augmenting patellar distalization using a hamstring autograft yields greater functional improvements, superior patella alta correction, and fewer complications compared to isolated MPFL reconstruction in adolescents with recurrent patellar instability. LEVEL OF EVIDENCE: Retrospective comparative study; level IV. CLINICAL

trial registrationClinical trial number: not applicable. This study is a retrospective comparative cohort study and does not meet the definition of a clinical trial as per the International Committee of Medical Journal Editors (ICMJE) guidelines, as it involves retrospective analysis of routinely collected clinical data without prospective intervention or randomization.