Minimally invasive double-plating osteosynthesis of the distal femur.

objectiveTechnical description of minimally invasive double-plating of the distal femur. INDICATIONS: Peri- and interprosthetic distal femur fractures with limited (periprosthetic) bone stock in geriatric patients. Re-operations (delayed and non-unions; infected non-unions) of the distal femur. Distal femoral fractures or femoral shaft fractures that do not qualify for femoral nailing and where the patient is unable to comply with weight-bearing restrictions. CONTRAINDICATIONS: Peri- and interprosthetic femoral fractures with unstable knee prosthesis and local soft tissue infection. Peri- and interprosthetic fractures of the proximal femur. SURGICAL TECHNIQUE: Supine position on a radiolucent table with both legs draped free. Support the knee to release traction on the distal fragment by the gastrocnemius muscle. Reduction and fixation of the fracture using a minimally invasive lateral approach. To reduce stress riser zones in interprosthetic fractures, the fixation device should overlap both the prosthesis by at least twice the diameter of the femoral diaphysis. Control plate position and reduction with special emphasis on length, rotation and longitudinal axes, using the healthy side as a reference. After sufficient reduction and fixation of the fracture, one proceeds to the medial plate fixation of the femur. Pre- or intraoperative contouring of a narrow large fragment locking compression plate into a helical shaped plate should be performed, using bending irons and a saw bone of a standard femur. The helical shaped plate is introduced submuscular and epiperiosteal in a minimally invasive fashion and fixed with bicortical locking screws. POSTOPERATIVE MANAGEMENT: Unrestricted weight bearing with walker or crutches under supervision of physiotherapist.

resultsBetween 2015 and December 2018, minimally invasive double-plate osteosynthesis using a medial helical shaped plate was performed in 11 patients. In 6 cases it was applied in patients (81 years ± 7 SD) with a supracondylar peri- or interprosthetic femoral fracture. No implant failure or loss of reduction was seen after postoperative unrestricted weight bearing. In the additional 5 cases double-plating was used in salvage procedures ([infected] non-unions, hardware failure). One of these patients developed a fracture-related infection for which all material was removed. The fracture healed after a new attempt of antegrade nailing combined with an additional locking plate. In the remaining patients complete bone healing without hardware failure was seen.