Analysis of retrograde femoral intramedullary nail placement through traumatic knee arthrotomies

OBJECTIVES:: To analyze the rate of postoperative infection after retrograde femoral nail placement in the setting of traumatic knee arthrotomy (KA). DESIGN:: Retrospective. SETTING:: Level-I trauma center. PATIENTS:: A review of all adult femur fractures (N = 1748) treated with an intramedullary nail over a 10-year period identified 34 retrograde nails with traumatic KA as the study group and 23 antegrade nails with traumatic KA as a control group. The retrograde femoral traumatic KA group was also compared with a 4:1 matched control group of 136 patients with retrograde femoral nails without traumatic KA. INTERVENTION:: Retrograde femoral nail placement with traumatic KA. MAIN OUTCOME MEASUREMENTS:: Occurrence of postoperative infection. RESULTS:: The traumatic KA groups treated with retrograde and antegrade femoral nails were similar across all recorded patient variables. No infections occurred in the retrograde traumatic KA group versus 1 infection (4.3%) in the antegrade traumatic KA group (P = 0.404). Four nonunions (11.8%) occurred in the retrograde traumatic KA group versus 1 nonunion (4.3%) in the antegrade traumatic KA group (P = 0.638). The matched control group of retrograde nails did not significantly differ when compared with the retrograde traumatic KA group for infection or nonunion (P = 1.000 and 0.261). CONCLUSIONS:: This is the first study to investigate retrograde nail placement through traumatic KA with comparison to control groups, with no differences found in infection rates. Furthermore, no infections (knee or fracture) occurred in those patients who were treated using a retrograde femoral nail with traumatic KA. This study documents the relative safety associated with retrograde femoral nailing in the setting of a concurrent traumatic KA with surgical debridement. LEVEL OF EVIDENCE:: Therapeutic level III. See Instructions for Authors for a complete description of levels of evidence.