The application of a hollow trephine in femoral retrograde intramedullary nailing technique.

Purpose: The purpose of this study was to describe and evaluate the use of a specially designed hollow trephine to create the entry point through the femoral condyle during retrograde interlocking intramedullary nailing for femoral fractures.

Methods: From June 2019 to December 2021, we treated 11 patients (5 men, 6 women; mean age, 64 years; age range 40-77 years) with mid-distal femoral fractures by retrograde intramedullary femoral nailing using a self-designed hollow trephine for femoral condyle reaming and cancellous bone harvesting. The mode of all the nails is static. Patients were followed up at 1, 4, 8, and 12 weeks and for at least 6 months after surgery. The healing process and heterotopic ossification were evaluated by imaging. Partial weight bearing was permitted during the recovery period and complete weight bearing was permitted after clinical healing of the fracture displayed by X-ray.

Results: The operation was successful in all patients. Over mean follow-up of 9.3 months (range, 6.0-12.0 months), all patients achieved clinical healing within three months. There were no complications such as knee joint infection, heterotopic ossification, knee joint adhesion and wedge effect.

Conclusion: The use of the hollow trephine during femoral retrograde intramedullary nailing helps avoid postoperative complications such as heterotopic ossification, knee joint adhesions, and wedge effect. It also facilitates bone graft harvesting.