Summary

revision knee arthroplasty provides, although not without complications, acceptable functional results for the treatment of periprosthetic fractures

Abstract

Introduction

Periprosthetic distal femoral fractures continue to rise in our setting, due to the increase in life expectancy of the population in our environment and the percentage of patients with total knee arthroplasty (TKA).
Given the complexity of these fractures and the characteristics of the patients, its treatment represents a real challenge for the orthopaedic surgeon. In some cases, in the absence of enough bone stock to perform internal fixation or due to loosening of the femoral component of TKA, we have to treat them with knee revision arthroplasty.

Objectives
To describe the results in our centre of the treatment of periprosthetic distal femoral fractures managed by revision knee arthroplasty, comparing the results with those described previously in the literature.

Material And Methods

Between 2011 and 2020, in the Orthopedic Surgery and Traumatology Department of the Hospital Universitario Príncipe de Asturias, 10 patients who presented periprosthetic supracondylar fracture of the distal femur (Rorabeck and Su classification) were managed by total knee revision arthroplasty. Their epidemiological data, functional results and complications were analysed after treatment.

Results

We registered 10 patients with supracondylar periprosthetic femoral fractures, with an average follow-up of 36.2 months. 80% of our cases were women, and the mean age recorded was 81.34 years.
Moreover, 8 (80%) were classified as type III according to Rorabeck’s classification and the remaining 2 (20%) as type II. All of them were catalogued as type III of Su.
All were treated by revision knee arthroplasty: 3 Endo-Model (Link), 2 Mega System C (Link) and 5 Nex Gen Segmental (Zimmer). The mean time until we perform surgery was 3.6 days and the mean interval of admission of 15.1 days. All the patients were allowed full weight bearing when discharged from the service.
During follow-up, all patients had good pain control but required technical aids for walking. The following complications were recorded: one case with paralysis of the external popliteal sciatic nerve (EPSN), and 2 patients with acute prosthetic infection who after several interventions required prosthetic replacement and knee arthrodesis.

Conclusions

Surgical treatment of supracondylar periprosthetic fractures of the distal femur ranges from conservative management, internal fixation with plate, intramedullary nailing, and revision arthroplasty. There are few studies in the literature that collect the results of the management of these kind of fractures using revision knee arthroplasty.
In our experience, revision knee arthroplasty provides, although not without complications, acceptable functional results in the medium term for the treatment of periprosthetic fractures of the distal femur in elderly patients, especially in cases of osteoporosis and significant loss of bone stock.
Despite this, it is considered necessary to continue the study in this field in order to have more scientific evidences that allows us to establish diagnostic-therapeutic algorithms for the management of these fractures, and thus improve the prognosis of these patients.