Operative Results of Periprosthetic Fractures of The Distal Femur In A Single Academic Unit.

BACKGROUND AND AIMS: Periprosthetic supracondylar fractures after total knee arthroplasty are often associated with poor bone stock, fracture comminution, and loose components. Current operative methods include plating, intramedullary nailing, and re-arthroplasty, depending on the fracture type. The aim of the study was to assess the outcome of operatively treated periprosthetic supracondylar fractures at our institute with special interest on the use of strut grafts in association with plating.

MATERIALS AND METHODS: In all, 68 patients were included in the study. They had been treated operatively due to a periprosthetic supracondylar fracture at our center between 2000 and 2010. The data of these patients were retrospectively collected from the electronic patient archives. Fractures with a fixed prosthesis component were treated using internal fixation provided that there was enough bone for osteosynthesis in the distal fracture fragment (39 patients). Fractures with a loose prosthesis component were treated using re-arthroplasty (29 patients). The demographics of the two treatment groups did not differ statistically significantly. Death or any re-operation was chosen as the endpoint of follow-up. Cumulative survival percentages were estimated for each treatment group.

RESULTS: There was no statistically significant difference between the treatment groups regarding clinical outcome. Clinical outcome was not assessable in nine patients. A positive clinical outcome was reported in 52 cases (88.1%). The survival of both laminofixation and re-arthroplasty was 75% at 3 years, but the survival of laminofixated fractures with strut graft was 80% compared to that of 51% without strut grafts. In all, 16 patients (24%) had a post-operative surgical site complication: seven infections (10%), six non-unions (15%), and three patellar dislocations (11%).

CONCLUSIONS: Post-operative surgical site complications were relatively common in these mainly elderly female patients. The survival percentages of the re-arthroplasty and laminofixation groups were similar. The use of strut grafts in association with plating may decrease re-operation rate.