ObjectiveTo investigate the effectiveness of intramedullary nailing fixation in semi-extended position via extraarticular parapatellar approach for tibial shaft fracture.MethodsBetween July 2018 and September 2019, 22 patients with tibial shaft fracture treated with intramedullary nailing fixation in semi-extended position via extraarticular parapatellar approach. There were 15 males and 7 females, with an average age of 46.4 years (range, 25-68 years). The fractures were caused by falling in 7 cases, by traffic accident in 14 cases, and by a heavy object in 1 case. Sixteen patients were closed fractures and 6 were open fractures. According to the AO classification, there were 4 cases of 42-A1 type, 2 cases of 42-A2 type, 3 cases of 42-A3 type, 3 cases of 42-B2 type, 4 cases of 42-B3 type, 2 cases of 42-C1 type, 3 cases of 42-C2 type, and 1 case of 42-C3 type. Twenty cases complicated with fibular fractures. The time from injury to operation was 2-15 days (mean, 7.5 days). The fracture healing time, complications, the incidence of anterior knee pain during the follow-up were observed; and knee joint functions were evaluated by Lysholm score at last follow-up.ResultsThe operation time was 50-140 minutes (mean, 85 minutes). Two cases experienced incision exudation which healed after symptomatic treatment. The incisions of other patients healed by first intention. All patients were followed up 8-23 months (mean, 14.9 months). X-ray films reexamination showed that all fractures healed with the healing time of 12-20 weeks (mean, 14.4 weeks). Four patients (18.18%) experienced the anterior knee pain. No patellofemoral instability was observed during the follow-up period. Lysholm score of knee function was 85-100 (mean, 94.3) at last follow-up. ConclusionApplication of the intramedullary nailing fixation in semi-extended position via extraarticular parapatellar approach is effective for tibial shaft fractures, which can not only realize the effective fixation of the fracture, but also avoid the adverse factors including re-displacement and anterior knee pain in the application of the intramedullary nailing fixation via the sub-patellar approach.