Suprapatellar versus infrapatellar approaches in the treatment of tibia intramedullary nailing: a retrospective cohort study

Tibial shaft fractures are routinely managed with intramedullary nailing (IMN). An increasingly accepted technique is the suprapatellar (SP) approach. The purpose of this study was to compare the clinical and functional outcomes of knee joint after tibia IMN through an suprapatellar (SP) or traditional infrapatellar (IP) approach. Retrospective analysis was performed in patients with tibial shaft fractures that were treated with IMN through a SP or IP approach between 01/01/2014 and 31/12/2016. The clinical and functional outcomes of the knee were assessed with the Hospital for Special Surgery (HSS) Knee Score. Secondary outcomes included the operation time and intraoperative blood loss. A total of 50 patients/fractures (26 IP and 24 SP) with a minimum follow-up of 15 months were evaluated. All fractures were OTA 42. No significant differences were found between the two groups in age, gender, side of fractures, operation time, intra-operative blood loss, and follow-up time. No significant difference was seen in HSS score (P = 0.62) between them. Sub analysis of all the HSS components scores revealed no significant differences between pain (P = 0.57), the stand and walk (P = 0.54), the need for walking stick (P = 0.60) and extension lag (P = 0.60). The other HSS components showed full scores (IP 10 vs. SP 10) in both approaches, including muscle force, flexion deformity and stability components. The range of motion (ROM) component score was superior in the IP group (P = 0.04) suggesting a higher ROM. Both SP and IP approach results in equivalent overall HSS knee scores. However, for the HSS component, the IP approach was superior to SP approach regarding the ROM.