Self-reported and performance-based outcomes following medial patellofemoral ligament reconstruction indicate successful improvements in knee stability after surgery despite remaining limitations in knee function

Purpose To evaluate short- to midterm outcomes of medial patellofemoral ligament reconstruction (MPFL) using patient-reported outcome measures and functional testing. Methods Twenty-four patients were examined regarding knee function after MPFL reconstruction, with a mean follow-up time of 45.3 +/- 18.4 months since surgery. Knee function was evaluated using the Tegner score, VAS, the knee injury and osteoarthritis outcome score (KOOS), the Lysholm score, SF-36 and EQ-5D-3L as well as functional scores. A group of uninjured persons of the same age and same gender composition was used for comparison. Results Eight (40%) patients managed to return to their pre-injury activity level. Five (25%) patients stated that they had experienced further patella dislocations after surgery but only two (10%) had sought medical help. Patients showed significantly poorer results in all PROMs compared to controls. The results obtained with SF-36 showed significant differences in physical health between the groups, but not in mental health. The functional performance test results showed overall poorer results for the patients versus controls: 11.5 sets for the square jump (6.7-15.7) versus 21 sets (18-26), 11.5 sets for the step-down test (6.5-15) versus 22 sets (18-26), and 77 cm for the single-leg hop for distance (32.2-110.5) versus 126 cm (115-37); all (P < 0.005). Conclusions After MPFL reconstruction, patients do not regain normal knee function, as measured by PROMs and functional tests, compared to an uninjured control group. Patients should be informed about residual functional limitations despite improved stability.