English

Abstract

Introduction The management of periprosthetic fractures is challenging and is guided by the configuration of the fracture, stability of implants and quality of the patient’s bone. This case report discusses the long-term fate of femoral allograft for periprosthetic fracture around a revision knee arthroplasty. Case report We present the operative technique and long-term fate of a bivalved femoral allograft used for the treatment of a periprosthetic fracture around a stemmed femoral component of a revision total knee arthroplasty (TKA) in a patient with rheumatoid arthritis and osteoporosis. Regular radiographic follow-up confirmed incorporation and docking of the allograft. A subsequent ipsilateral femoral neck fracture 4 years after allograft implantation was treated with routine total hip replacement. Conclusion The use of femoral allograft for augmenting fixation of periprosthetic fractures above a TKA is not widely reported, and, at 11 years, this case represents the longest published follow-up above a revision TKA. Our case supports the use of a bivalved total femoral allograft in the treatment of long-bone periprosthetic fractures with poor bone stock. Introduction Data from joint registries indicate an increase in the number of primary and revision knee arthroplasties being performed each year internationally, and the volume of revision knee arthroplasty being performed in the USA alone is expected to increase by 601% between 2005 and 20301. Periprosthetic supracondylar femoral fractures can occur intraoperatively and postoperatively, with an overall incidence of 0.3–2.5% above primary total knee arthroplasties (TKAs)2–7. Estimates of the incidence after revision knee arthroplasty vary greatly from 1.7% to 38%3,6–8, with most reports quoting closer to 2%. Periprosthetic femoral fractures above TKA and revision TKA have historically been associated with high complication rates when treated nonoperatively or with internal fixation4,5,9. Periprosthetic fractures are more common in the elderly population and in females7. Additional risk factors include rheumatoid arthritis, chronic steroid treatment, reduced bone stock, neurological disorders, revision surgery, notching of the anterior cortex of the femur, and in particular poor bone stock3,9–11. Primary osteopenia or secondary to stress shielding around a stemmed revision femoral component further increases the difficulty of achieving good fracture fixation by traditional methods. Whilst the introduction of locked plate technology has revolutionized surgery in the presence of osteoporotic bone12, the use of a combination of cortical femoral allograft and compression plate13 or a bivalved total femoral allograft5,14 may be indicated when a periprosthetic fracture around a well-fixed implant is complicated by deficient bone stock or significant comminution. Unfortunately, there remains insufficient evidence to strongly support the use of a single method of surgical treatment in this complex fracture group. In this case report, we aim to provide further evidence that a bivalved total femoral allograft can be successfully used in the treatment of periprosthetic femoral fractures above/around a well-fixed stemmed revision TKA and that incorporation of the graft with the host femur is possible thereby increasing the patient’s bone stock. This technique can provide a reliable long-term solution in this complex fracture group. Case report One month after primary TKA for valgus arthritis, a 60-year-old lady with polyarticular rheumatoid arthritis and severe osteoporosis re-presented with a sintering fracture of the lateral femoral condyle after a simple stumble. The femoral component was revised to an uncemented stemmed implant, and the lateral femoral condyle was reconstructed with femoral head structural allograft. Three months after discharge, she fell and sustained a spiral periprosthetic fracture around the femoral stem (Figure 1). * Corresponding author Email: gavin.macpherson@nhs.net 1 Department of Orthopaedic Surgery, The Royal Infirmary of Edinburgh, 51 Little France Crescent, Old Dalkeith Road, Edinburgh, EH16 4SA, UK 2 Stiftung Orthopadische Universitatsklinik, Schlierbacher Landstrase 200a, 69118 Heidelberg, Germany 3 Orthopadischen Klinik Paulinenhilfe, Diakonie Klinikum Stuttgart, Rosenbergstrasse 38, D-70176 Stuttgart, Germany 4 Endoklinik Hamburg, Holstenstr. 2, 22767 Hamburg, Germany