Functional hop performance remains impaired in children and adolescents 2 years after medial patella femoral ligament reconstruction compared to matched healthy controls

Purpose This study aimed to investigate the patient‐reported outcomes and functional outcomes of children and adolescents who underwent medial patella femoral ligament (MPFL) reconstruction surgery compared to healthy peers without a history of traumatic patellar dislocation. Methods Thirty‐nine young patients underwent MPFL reconstruction with a quadriceps tendon and suture anchor technique at Aarhus University Hospital (2016–2022) and were compared with 39 age‐ and sex‐matched healthy controls. The patient‐reported outcome measures used were the anterior knee pain scale (Kujala) and the banff patella instability instrument (BPII 2.0). Palpable knee pain and patellar lateralisation were evaluated by manual test. The test battery included functional one‐ and three‐hop distance tests, a side‐hop test and tests of isometric knee extension and hip abduction strength. Results At the follow‐up, the median age of the patients in both groups was 17.6 years (range 13–25 years), and 37% (14 patients) had undergone MPFL reconstruction in both knees. The median Kujala score after 2 years was 89 (interquartile range [IQR]: 76–92) and 100 (IQR: 96–100) ( p < 0.001), and the median BPII score was 67 (IQR: 47–85) and 99 (IQR: 97–100) ( p < 0.001) in patients and healthy matched peers, respectively. Sixteen percent (six patients) experienced localised pain following MPFL reconstruction and 50% (19 patients) exhibited patellar lateralisation of over 25%. Furthermore, reduced hop test performance of 24%, 20% and 39%, respectively, were observed in patients for one‐, triple‐ and side‐hop tests, compared to their healthy matched peers. Reductions in strength were found to be 8% for knee extension and 18% for hip abduction for the patients compared to healthy matched peers ( p < 0.001). Conclusion Children and adolescents with MPFL reconstruction have more knee symptoms and worse knee function after 2 years compared to their healthy peers. Level of Evidence Level III.