Arthroscopic Anatomical Double-Bundle Medial Patellofemoral Complex Reconstruction Improves Clinical Outcomes in Treating Recurrent Patellar Dislocation Despite Trochlear Dysplasia, Elevated Tibial Tubercle-Trochlear Groove Distance, and Patellar Alta

Abstract

Purpose: To evaluate the clinical outcomes of arthroscopically assisted double-bundle medial patellofemoral complex reconstruction (MPFC-R).

Methods: A retrospective review was carried out among adult patients who experienced at least 2 patellar dislocations and underwent primary arthroscopically assisted MPFC-R between January 2014 and November 2019. Dejour classification, tibial tubercle-trochlear groove (TT-TG) distance, and patellar height (with Insall-Salvati index) were measured. Pre- and postoperative patellar tilt were compared. Information on outcome scores, ability to return to sports, postoperative recurrent dislocations, and complications was recorded.

Results: A total of 42 MPFC-Rs in 39 patients were included. Mean age at surgery was 22.2 ± 7.6 years; 69.2% of patients were female. Mean follow-up was 47.3 ± 20.2 months. Seventy-four percent of cases had Dejour B (19.0%), C (33.3%), and D (21.4%) trochlear dysplasia; mean TT-TG distance was 19.6 ± 3.5 mm, and mean Insall-Salvati index was 1.21 ± 0.17. Mean patellar tilt decreased from 27.6 ± 11.6° to 9.4 ± 6.5° (P < .001). All patients had statistically significant (P < .001) improvement in mean International Knee Documentation Committee (IKDC) (44.9 ± 18.2 to 87.5 ± 6.9), Lysholm (61.4 ± 16.6 to 94.1 ± 6.4), Kujala (56.0 ± 16.8 to 92.9 ± 5.3), and Tegner score (2.7 ± 1.3 to 4.6 ± 1.4). The majority of patients (96.9%) returned to sports, with 90.3% returning to the same or greater level of activity. No postoperative dislocations or subluxations were reported.

Conclusions: Arthroscopically assisted double-bundle MPFC-R is a promising procedure to treat recurrent patellar instability at 2- to 7-year mid-term follow-up, despite the presence of trochlear dysplasia, elevated TT-TG distance and patellar alta. The improvement of IKDC score exceeded the minimal clinically important difference in 95.2% patients, and 66.7% surpassed the patient acceptable symptomatic state based on postoperative IKDC score with no redislocations being reported at latest follow-up.

Level of evidence: Level IV, case series, retrospective.