Comparison of the LISS and a retrograde-inserted supracondylar intramedullary nail for fixation of a periprosthetic distal femur fracture proximal to a total knee arthroplasty.
Simulated supracondylar fractures were created proximal to posterior cruciate ligament-retaining total knee arthroplasty components in paired human cadaver femora and stabilized with either a retrograde-inserted locked supracondylar nail or the Less Invasive Stabilization System (LISS; Synthes USA, Paoli, PA). Loads were applied to create bending and torsional moments on the simulated fracture stabilized with either no gap or a 10-mm gap. The LISS exhibited less torsional stability with anterior (P<.001) and posterior loads (P<.01). When varus loads were applied to 10-mm-gap specimens, the specimens stabilized with a retrograde nail had an 83% reduction in fracture displacement (P<.001) and 80% less medial translation of the distal fragment (P<.001). The samples stabilized with the LISS had a 93% reduction in fracture gap displacement when a valgus load was applied with a 10-mm gap (P<.001). Overall, these results suggest that the retrograde-inserted nail may provide greater stability for the management of periprosthetic supracondylar femur fractures in patients with a posterior cruciate ligament-retaining femoral total knee arthroplasty component.
Bong
Matthew R
MR
Department of Orthopaedic Surgery, NYU-Hospital for Joint Diseases New York, New York 10003, USA.
Egol
Kenneth A
KA
Koval
Kenneth J
KJ
Kummer
Frederick J
FJ
Su
Edward T
ET
Iesaka
Kazuho
K
Bayer
Jordi
J
Di Cesare
Paul E
PE
D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D016267:External Fixators; D005264:Femoral Fractures / Q000209:etiology / Q000601:surgery*; D005594:Fracture Fixation, Intramedullary; D006801:Humans; D016896:Treatment Outcome