Challenge of managing distal femur fractures with long-stemmed total knee implants.

OBJECTIVE

Treatment of distal femur fractures by long-stemmed total knee arthroplasty (TKA) is challenging, because of poor bone stock, decreased blood supply, history of multiple knee surgeries and an absence of standard treatment. Few published studies are available concerning this. The purpose of this study was to share surgical technique and better describe our patients' comorbidities, which add to the challenge of managing individuals with these fractures.

METHODS

Between August 2008 and September 2013, seven patients presented to our level I trauma center with distal femoral fractures associated with long-stemmed TKA implants. Their average age was 68.71 years (range, 52-81 years).The most common mechanism of injury was fall (five patients), followed by a traumatic fracture of the femur while walking (one patient), and being lifted out of bed (the one nonambulatory patient). This retrospective study reports a treatment protocol, including surgical technique, and short-term outcome in seven patients in whom locking compression plates (LCP) were used.

RESULTS

Six fractures were classified as Rorabeck type II, and one as type III. The average time to full-weight-bearing was 5.5 months. At this institution, good short-term results have been achieved by using an LCP with screws placed proximal to the long-stem and distal to the fracture. The six patients all achieved full-weight-bearing,taking an average of 5.5 months (range, 3-7 months).

CONCLUSIONS

LCP is an effective form of management of distal femur fractures around long stem TKAs. An individualized operative approach possibly incorporating bone-graft substitutes, cerclage wire and a post-operative bone stimulator is recommended.