Abstract
We present five case studies of a new technique for the treatment of distal femur fractures after total knee arthroplasty. This type of fracture is rare, but when it occurs can present a dilemma as to the correct treatment. If the prosthesis is loose, the logical treatment is revision surgery with the use of long stem stabilisation. If the prostheses are firmly fixed, the best method of treatment is difficult to determine. Intramedullary fixation is a well-known modality, but proper fixation distal to the fracture can be problematic in very distal fractures.
We performed intramedullary fixation of these fractures, using standard retrograde condylar locking nails inserted through the notch of the femoral prostheses. The problem of distal fixation was solved by fixating the nail to the femoral prostheses with a plate that fitted into the notch of the pros-theses and was securely fixed to the nail with a custom-made screw. This not only gave alignment stability but also aided in compression of the fracture. A locking screw distal to the fracture line was inserted in some patients to aid fixation. but could not be placed in others owing to the distal position of the fracture. Autograft was used in most cases to aid fracture healing. Postoperatively the leg was immobilised in a cast for six weeks.
This method of fixation of the nail to the prostheses has not been described in the literature to date. We believe that this technique offers a new modality in treating these complex fractures, providing adequate fixation, alignment and compression stability.
The abstracts were prepared by Professor M. B. E. Sweet. Correspondence should be addressed to him at The Department of Orthopaedic Surgery, Medical School, University of Witwatersrand, 7 York Road, Parktown, Johannesburg, 2193 South Africa
