Treatment of Symptomatic Bipartite Patella by Fragment Excision, Capsular Repair and Novel ITB Release

Abstract

Objectives:The aim of this paper is to present the mid-term results of a novel technique used to treat symptomatic bipartite patella.Methods:Diagnosis of symptomatic bipartite patella was made by history, examination, Xray, MRI and/or bone scan. Patients with typical localised pain, pain on manually stressing the fragment, a positive ITB tightness test, a typical Xray and either, a hot bone scan or bone oedema on MRI were considered for treatment. All patients had a pre-op Kujala and Lysholm score recorded.Surgical Technique:Under GA and tourniquet a 4 part procedure was performed: Routine arthroscopy to assess patella tracking and fragment stabilityA 2 cm incision was made on the distal thigh 10-12 cm above the joint line over the ITB. A zig-zag incision was made across the ITB/IPB from anteriorly to the corner of the intermuscular septum.A 4 cm incision was made over the edge of the lateral patella. A longitudinal capsular incision was made at the edge of the patella. The capsule was reflected off the dorsal patella by sharp dissection and the bipartite fragment was excised through the synchondrosis.A watertight repair of the lateral capsule was performed with absorbable suture. Routine closures were performed.Comment:The author considers the ITB/IPB to be an important factor in the development and progression of the disorder. The addition of the novel release allows a tension-free capsular repair, reducing lateral facet loads, improving patella tracking without affecting patella stabilityResults:Over an 11 year period twenty patients underwent the procedure. 15 were available with a minimum 2 year and mean 6.35 year follow-up. Pre-op and post-op Kujala and Lysholm scores were compared. Patients were predominantly male (14:1) between ages 10-54 years. A clear history of trauma was present in 6 patients while in 9 symptoms were related to overuse. The pre-op Kujala score ranged from 28-90 with an average of 59. Post-op scores improved markedly with range 70-100 with 12 patients (80%) scoring >90 and an average improvement of 32 pts. Lysholm scores similarly improved significantly, with an average 32 pts improvement (range 1-66). Complications were minimal.Conclusion:Fragment excision, capsular repair and novel ITB release resulted in significant reproducible improvements in both objective and subjective outcome measures. Resolution of symptoms occurred in all patients suggesting the technique is a useful option in the treatment of symptomatic bipartite patella.