OTA 2012 Posters

Scientific Poster #34 Hip/Femur OTA-2012

Is it Safe to Place a Retrograde Femoral Intramedullary Nail Through a Traumatic Knee Arthrotomy?

Jesse E. Bible, MD; Rishin J. Kadakia, BA; Ankeet A. Choxi, MD;
Jennifer M. Bauer, MD; Hassan R. Mir, MD;
Vanderbilt Orthopaedic Institute, Nashville, Tennessee, USA

Purpose: Retrograde intramedullary nailing of femur fractures in the setting of a traumatic knee arthrotomy (TKA) has been thought by some surgeons to lead to an increased risk of postoperative infection. This stems from the concern of inserting an intramedullary nail through a possibly contaminated knee; however, this belief has never been investigated clinically. The purpose of this study was to analyze the rate of postoperative infection and nonunion following retrograde femoral nail placement in the setting of a traumatic knee arthrotomy with comparison to control groups.

Methods: A retrospective review of all adult femur fractures (N = 1748) treated at a single Level I academic center over a 10-year period identified 67 patients (41 retrograde femurs, 26 antegrade femurs) with ipsilateral TKAs. All ballistic injuries and those patients with <6 months of follow-up to union were excluded, leaving 32 retrograde femoral nails with TKA as the study group and 26 antegrade femoral nails with TKA as a control group. Rates of postoperative infection (knee or fracture site) and nonunion were then compared between the retrograde and antegrade groups. Infection was defined as those treated with surgical débridement and irrigation, while nonunion was confirmed with radiographic review or with requirement for surgical revision. The retrograde femoral TKA group was also compared to a 4:1 matched control group of 128 patients with retrograde nails without a TKA. These controls were matched for age, injury (closed/open; if open, Gustilo type), diabetes, and smoking.

Results: The TKA groups treated with retrograde and antegrade intramedullary femoral nails did not differ significantly across all recorded variables, including age, diabetes, smoking, injury mechanism, arthrotomy size, and percentage of open fractures (P = 0.152-1.000). Four nonunions (12.5%) were identified in the retrograde TKA group versus one nonunion (4.8%) in the antegrade TKA group (P = 0.637). Similarly, no infections occurred in the retrograde TKA group versus one infection (4.8%) in the antegrade TKA group (P = 0.396). The matched control group of retrograde nails in patients with no TKA had 8 nonunions (6.3%) and 2 infections (1.6%). The rates did not significantly differ when compared to the retrograde TKA group (P = 0.260 and 0.361, respectively).

Conclusions: This is the first study to investigate retrograde femoral nail placement through a traumatic knee arthrotomy (TKA) with comparison to 2 control groups (antegrade nails with TKA, retrograde nails without TKA), with no difference found in union rates or infection. Furthermore, there were no postoperative infections in those patients treated with a retrograde nail in the setting of a TKA. This study documents the relative safety associated with retrograde femoral nailing in the setting of a concurrent TKA with appropriate surgical débridement.

• The FDA has not cleared this drug and/or medical device for the use described in this presentation   (i.e., the drug or medical device is being discussed for an “off label” use).  ◆FDA information not available at time of printing. Δ OTA Grant.