TFNA Implant Failure with Helical Blade Cut-out.

INTRODUCTION: Trochanteric femoral nail-advanced (TFNA) was introduced in the market with better nail design, better alloy (titanium molybdenum) and both sliding and static locking options of the helical blade. Although, it was devised to overcome the shortcomings of roximal Femoral Nail Anti-rotation (PFNA), it still can have complications, if the principles of fracture management are not met. Here, we report a case of a TFNA implant failure with helical blade cut-out in an elderly osteoporotic patient treated for inter-trochanteric femur fracture. To the best of our knowledge, this is the first report of helical blade cut-out wit TFNA nail in world literature.

CASE REPORT: An 83-year-old female patient was treated with a TFNA nail for inter-trochanteric femur fracture (AO 31A2.1). An acceptable reduction and stable fixation were achieved. The position of the helical blade in the head was in the optimal position with a tip apex distance (TAD) of 29 mm. The patient presented to us 6 weeks later with implant failure with helical blade cut out after a history of fall. Cemented bipolar hemiarthroplasty with calcar reconstruction using a mesh was done. The patient was clinically asymptomatic and was walking full weight-bearing till her last follow-up at 14 months.

CONCLUSION: We can associate the failure seen in our case with an increased TAD of 29 mm, osteoporotic bone and a neutral to negative variance. Helical blade cut-out was seen as the blade was locked onto the nail with insufficient hold onto the osteoporotic head fragment which collapsed into varus, leading to cut-out. This case report emphasizes the importance of TAD, valgus reduction, and positive variance in avoiding implant failures, even with a newer implant like TFNA which was developed to improvise onto the shortcomings of PFNA nail.