The semi-extended infrapatellar intramedullary nailing of distal tibia fractures: a randomized clinical trial

Background: Malalignment is a common event during the intramedullary nailing (IMN) of distal tibia fractures (DTFs). Although it is reported that the semi-extended IMN techniques such as suprapatellar (SP) and parapatellar (PP) approaches may be superior in preventing malalignment, the application of these techniques is concerning owing to the intra-articular involvement. We thus developed an extra-articular semi-extended infrapatellar (SEIP) approach which utilizes the infrapatellar (IP) space while maintaining the knee in a semi-extended position. However, there are no studies on the safety and efficacy of SEIP in treating DTFs. Therefore, in this study, the SEIP technique was examined, particularly in terms of the potential alignment improvement of DTFs, and this technique was compared with the traditional hyperflexed infrapatellar (HFIP) procedure. Materials and methods: This randomized clinical trial (RCT) compared IMN malalignment while correcting extraarticular and nondisplaced intra-articular DTFs between April 2018 and June 2021 using the HFIP and SEIP techniques at a level I trauma center in China. The study participants were clinically and radiographically examined for at least 12 months of follow-ups. lntraoperative fluoroscopy time, operation time, blood loss, hospitalization duration, functional ankle score, and complications were assessed as well. Results: Among the 88 recruited participants, 45 (51%) underwent traditional HFIP IMN and 43 (49%) underwent SEIP IMN. Malalignment occurred in 9 patients (20.0%) from the HFIP cohort and in 2 patients (4.7%) from the SEIP cohort (P value= 0.030). In addition, the SEIP IMN technique significantly reduced the intraoperative fluoroscopy time, operation time, and improved the postoperative ankle function compared to the HFIP IMN technique. However, the intraoperative blood loss, hospitalization duration, infection, delay union, and nonunion remained the same between the two cohorts. Conclusions: In summary, we demonstrated that the SEIP IMN provides markedly enhanced alignment of extraarticular and nondisplaced intra-articular DTFs compared to the traditional HFIP IMN procedure. The described technique represents an effective option for IMN of DTFs.