Retrograde intramedullary nailing of supracondylar femoral fractures: design and development of a new implant

Since 1992 we have developed an implant in which the distal (condylar) screws have a diagonal configuration so that the screws can be closer to the distal end of the nail, allowing more distal fractures to be fixed. It also utilises the denser bone of the posterior condyles for more secure fixation in osteoporotic patients. The new implant was used for 24 extra-articular fractures from September 1994 to September 1997, and for 14 articular fractures from February 1995 to December 2000. There was no significant difficulty with obtaining fixation in very distal fractures and in osteoporotic bone. Early weightbearing was encouraged in those with extra-articular fractures. All fractures united within 3 months except one which required a bone graft (but no revision of implant) at 6 months. Average knee flexion at final followup was 101 degrees for extra-articular fractures and 106 degrees for articular fractures. Complications included quadriceps adhesions requiring further surgery in two patients who had open fractures, and malunion in one patient who had an early design of the implant and a 4.5mm condylar screw broke. Nine patients required late removal of condylar screws due to local soft tissue irritation.