Summary

MPFL reconstruction and lateral release are effective in management of lateral patellar instability

Abstract

Background

Patellar instability is prevented by both static (bony) and dynamic (musculo-ligamentous) restraints. Therefore, among the stabilization procedures for lateral patellar instability is the commonly performed medial patello-femoral ligament (MPFL) reconstruction with concomitant lateral release.

Aim

Is to evaluate the efficacy of the aforementioned procedure in terms of radiological and functional outcome following the procedure.
Study methodology: All the patients who presented to Ghurki Trust Teaching Hospital Lahore with lateral patellar instability and underwent MPFL reconstruction alongside lateral release after 2018 and had complete record available as per the study requirements were retrospectively studied. Final sample size was 47 and mean follow-up period was 17.5 (12-26) months. Pre- and post-operative radiology was studied to determine congruence, patellar tilt and lateral patellar angle. Furthermore, globally validated scoring systems including Kujala, Lyshom and tegner activity score were calculated both preoperatively and postoperatively; and finally comparison was performed. Subjective assessment was done in terms of Nelitz criteria.

Results

Comparison of pre- and post-op radiology depicted improvement of congruence angle from 18.7+-4.8 to a value of -4.9+-0.7. Similarly, dependent sample t-test revealed statistically significant (p<0.05) improvement in lateral patellar angle from 7.9+-3.9 to 6.1+-2 on last follow up. Moreover, patellar tilt angle showed improvement from 27.6+-6. 7 to 6.1+-0.9 . Alongside the aforementioned radiologic improvement, physiologic improvement was noted in terms of rise in all the three scores assessed. Lychom score rose significantly (p<0.05) from a preoperative mean 41.6+-6.7 to postoperative mean 93.92. Similarly, mean Kujala score improved from 42.3+-7.1 points to 91.2+-6.2 and mean tegner score climbed to 6.9+-1.1from preoperative mean of 2.4+-0.6. Subjective assessment by Nelitz score revealed that 59% of the patients were “very satisfied”, 38% were “very satisfied” and 7% were “satisfied” with the results. None of the studied cases developed any neurological or vascular complications: though, superficial surgical site infection was noted in a single scenario that settled with oral antibiotics.

Conclusion

MPFL reconstruction combined with lateral release is associated with significant improvement in stability of lateral patellar instability. Both radiological and physiological improvement in terms of stability are associated with the procedure: yet, further research on the subject in terms of higher level evidence generating study designs as randomized control trials are encouraged .
Keywords: MPFL reconstruction, lateral release, patellar instability.