Patellar complications in single versus double tunnel medial patellofemoral ligament reconstruction

Hamstring graft fixation on the patellar side during medial patellofemoral ligament (MPFL) reconstruction is usually with transosseous tunnels and can frequently lead to further problems. The aim of our study was to compare and analyse patellar complications in single patellar tunnel versus double tunnel hamstring graft fixation.

Twenty-nine knees with MPFL reconstructions (group S) in which the hamstring tendon graft was transfixed using a suspensory fixation method in a single tunnel drilled across the patella were analysed in comparison with 29 knees (group D) with interference fixation of the graft through two tunnels drilled up to a predetermined depth in the patella. Primary outcome measured was any patellar complication like anterior knee pain and patella fracture. Secondary outcomes assessed were future functional instability and failure of reconstruction.

Anterior knee pain was noted in six patients in group S, of which three patients had removal of the irritating metalwork on the patella. In all, nine surgical interventions were needed in six patients in this group. Three patients in group D complained of knee pain, but no one in this group needed any further surgical interventions ( p value 0.02). Symptomatic instability requiring revision surgery or realignment surgery was required in two patients in the group S and none in group D. No patellar fractures were seen in either group.

Our study showed increasing problems with single tunnel patellar fixation, with more reoperation and failure rates compared to double tunnel fixation. The evidence supports the move towards anatomical double bundle MPFL reconstructions.