A Suprapatellar approach, when compared to an Infrapatellar approach, yields less Anterior Knee Pain and better patellofemoral joint Function, for intramedullary nailing of diaphyseal tibial fractures. Results of a Randomised Controlled Trial.

Abstract

To assess if a suprapatellar (SP) approach, when compared to an infrapatellar (IP) approach, yielded less patient reported anterior knee pain and higher patellofemoral joint function at 6 weeks and 12 months post operatively, when treating tibial fractures with intramedullary nailing. Prospective, parallel group randomized control trial. Tertiary level one trauma care centre, Brisbane, Australia. Skeletally mature patients with an acute diaphyseal tibial fracture (AO/OTA 41A2/3, 42 A1- 43A3) amenable to an IMN were included. Exclusion criteria were peri-prosthetic fractures, nonunions, and presence of a contralateral injury that would restrict weightbearing. Anterior knee pain, through the visual analogue scale (VAS) and patellofemoral function using the Kujala scale at 6-weeks and 12-months were compared between those treated with a SP and IP approach. 95 tibia fractures were included in the randomized trial, with complete follow-up data for 44 and 46 tibia fractures in the SP and IP groups, respectively. The SP cohort exhibited better patella-femoral knee function at both 6 weeks post operatively (Kajula 53.0 for SP vs 43.2 for IP, p<0.01)) and 12 months (Kujala 92.0 for SP vs 81.3 for IP (p<0.01)), and a reduction in anterior knee pain at 12-months post-operatively (VAS 0.7 SP vs 2.9 IP, p<0.01). This randomized trial demonstrated clinically meaningful differences in patellofemoral function, for a suprapatellar versus infrapatellar approach, with a greater than 10 point discrepancy in Kujala score at both 6 weeks and 12 months. Additionally, there was a clinically important difference in VAS knee pain scores for patients at 12 months, but not at 6 weeks, post operatively. These results contribute to the growing body of evidence demonstrating the functional and clinical benefits of the suprapatellar approach.