Medial buttress plate augmentation of cannulated screw fixation in vertically unstable femoral neck fractures: Surgical technique and preliminary results

Abstract

Objective: To evaluate the outcome and complications of unstable Pauwels type 3 femoral neck fractures treated with a combination fixation of three cannulated screws and a medial buttress plate.

Patients and methods: From October 2015 to June 2016, 28 patients under 60 years of age with Pauwels type 3 femoral neck fracture were treated with open reduction and internal fixation using a direct anterior approach. Fracture consisted of three cannulated screws augmented with a medial buttress plate. All reductions achieved Garden's alignment index grade one. Touch down weight bearing was permitted post-operatively for 6 weeks, and subsequently advanced to full weight bearing. One patient was lost to follow-up, which the remaining 27 patients were followed at 1 week, 6 weeks, 3 months, 6 months and 12 months post-operatively.

Result: Union without femoral neck shortening was achieved in 89% of cases. Implant failure was seen in 3 cases and was associated femoral neck shortening. Reduction loss with backing out of the cannulated screws occurred in these cases, and in one case there was also plate and screw breakage. There were no cases of avascular necrosis identified at a mean follow-up was 13.6 months CONCLUSION: At short time follow-up, treatment of Pauwels type 3 femoral neck fractures using cannulated screws combined with medial buttress plate improves the fracture union rate compared to historical series using cannulated screws alone. The method of medial buttress plate augmentation does not appear to increase any implant related complications, including avascular necrosis.

Keywords: Buttress plate; Cannulated screws; Pauwels type 3 fracture; Vertical unstable femoral neck fracture.