Fixation of Periprosthetic Supracondylar Femur Fractures Above Total Knee Arthroplasty – The Indirect Reduction Technique with the Condylar Blade Plate and the Minimally Invasive Technique with the LISS

Abstract

Supracondylar fractures of the femur after total knee arthroplasty are an uncommon but highly challenging injury (Streubel et al., 2010). The management of distal femoral fractures following a total knee replacement can be complex and requires the equipment, perioperative support and surgical skills of both trauma and revision arthroplasty services (Johnston et al., 2011, Nauth et al., 2011). The incidence of periprosthetic supracondylar femur fractures after total knee arthroplasties ranges from 0.3% to 2.5%. A patient with revision total knee arthroplasty has a significantly higher risk of supracondylar fracture above the prosthesis (2-4%) (Merkel & Johnson, 1986; Berry, 1999). Interprosthetic femoral fractures tend to occur more frequently in the supracondylar region above total knee arthroplasty components (Mamczak et al., 2010). Predisposing factors are female gender, poor bone stock, rotationally constrained implants, stress risers such as screw holes around the knee, malalignment of the prosthesis, endosteal ischaemia (bone cement, spongiosa preparation), anterior femoral notching, arthrofibrosis, chronic steroid use, rheumatoid arthritis, revision total knee arthroplasties, poliomyelitis and Parkinson’s disease (Table 1, Aaron & Scott, 1987; Ayers, 1997; Berry, 1999; Bogoch et al., 1987; Cain et al., 1986; Cordeiro et al., 1990; Culp et al., 1987; Diehl et al., 2006; DiGioa et al., 1991; Figgie et al., 1990; Haddad et al., 1999; Hirsh et al., 1981; Lesh et al., 2000; Merkel et al., 1986; Moran et al., 1996; Ritter et al., 1988; Roscoe et al., 1989; Shawen et al., 2003; Short et al., 1981; Sisto et al., 1985; Wick et al., 2004; Zehntner & Ganz, 1993). A biomechanical study has shown that notching of the anterior cortex significantly lessens the load to failure by decreasing the bending strength by 18% and the torsional strength by approximately 40% (Lesh et al., 2000). In a retrospective study, the clinical results of 1089 consecutive total knee replacements demonstrated no difference in knees managed with or without anterior femoral notching (Ritter et al., 2005). This finding emphasises the potential for osseous remodelling to decrease the risk of