Equivalent outcomes without increased morbidity in MPFL reconstruction and distalising tibial tubercle osteotomy versus isolated MPFL reconstruction.

Importance/aims: Isolated MPFL reconstruction (MPFLR) and, concomitant MPFLR with tibial tubercle osteotomy (MPFLR + TTO) are common operations for recurrent patellar instability. The addition of a TTO procedure has been associated with higher patient morbidity, slower recovery and a greater complication risk(Payne et al., 2015) .11 This study aimed to investigate the post-operative mid to long-term clinical outcomes of MPFLR compared with MPFLR and concomitant distalising TTO performed for patella alta. Methods: Patients from a specialist orthopaedic clinic who underwent an MPFLr ± TTO between 2006 and 2020 were contacted to report their clinical and functional outcomes after at least 12 months post-op. 70 patients consisting of 73 operated knees, responded. Caton-Deschamps index, sulcus angle, TT-TG and patellar tilt were assessed from pre-op MRIs by two independent reviewers. Statistical analysis was performed to compare post-operative outcomes and radiographic measurements between groups. Results: There was no difference in post-operative outcome measures, re-dislocation rate or rate of return-to-sport between cohorts. Both cohorts had a high preoperative incidence of patellar alta, trochlear dysplasia and patella tilt. The MPFLR + TTO cohort had a greater preoperative patellar height and greater degrees of patellar tilt than the MPFLR cohort. Conclusion: While an additional TTO is known to be associated with a higher post-operative morbidity risk, in the present study, both cohorts had equivalent post-operative outcomes without increased morbidity. Patients with anatomical variants such as greater patellar height may benefit from an additional TTO in the mid-to long-term. Level of evidence: Level III.