Outcomes of surgical management of closed periprosthetic distal femur fractures above total knee arthroplasties: A case series

Introduction

Periprosthetic distal femur fractures present difficult treatment challenges and are expected to become more prevalent as the number of total knee arthroplasties (TKAs) continues to rise. The purpose of this study is to determine the functional outcomes and rate of re-operation following surgical treatment of closed distal femoral periprosthetic fractures above a TKA.

Methods

We performed a retrospective review of 56 patients (45 females) who underwent surgical management of distal femur fractures (AO/OTA 33) above an ipsilateral TKA with a mean follow-up of 21 months (range, 12–78 months). Forty-three (77%) patients were treated with a lateral plate and screw construct, and 13 (23%) patients were treated with a retrograde intramedullary nail.

Results

There were 2 (4%) deep infections at a mean of 6 months (range, 5–7 months) post-operatively. At final follow-up, TKA components were retained in 53 (93%) patients, demonstrating a survivorship free of component revision following fracture treatment of 93% at 6.5 years. Survivorship free of any re-operation following fracture treatment was 86% at 6.5 years. Mean anatomic lateral distal femoral angle (aLDFA) was 84° (range, 72–89°) and mean anatomic posterior distal femoral angle (aPDFA) was 83° (range, 67–89°). There were 8 nonunions (14%) at 6 month follow-up, and no patients underwent a re-operation for malunion.

Conclusion

This case series demonstrates increased revision rates and decreased survivorship of TKA components after surgical management of periprosthetic distal femur fractures. Surgeons must be aware of these potential complications when treating patients with periprosthetic distal femur fractures and counsel their patients appropriately.

Level of Evidence

Therapeutic Level IV. See instructions for all others for a complete description of levels of evidence.