OTA 1997 Posters - Scientific Basis for Fracture Care

Femoral and Cruciate Blood Flow after Retrograde Femoral Reaming

Amr W. ElMaraghy, MD, Emil H. Schemitsch, MD, FRCS(C), Robin R. Richards, MD, FRCS(C)

St. Michael's Hospital, Univ. of Toronto, Toronto, Ontario, Canada

Purpose: To determine the effect of retrograde femoral reaming on the blood flow of the distal femur and the cruciate ligaments.

Conclusion: Retrograde femoral reaming with an intercondylar notch entry portal results in an increase in bone blood flow to the distal femur, but a sharp decrease in perfusion to the nearby cruciate ligaments.

Significance: Vascular insult to the cruciate ligaments during retrograde femoral reaming may predispose to subsequent injury and adversely affect rehabilitation of the knee following femoral fracture fixation.

Summary of Method, Results, and Discussion: Retrograde femoral reaming and intramedullary nailing has recently become a popular option for the treatment of distal femoral and some femoral shaft fractures. Concerns persist regarding the effect of reaming via an intraarticular start point in the intercondylar notch. The effect of retrograde reaming on the blood flow of the distal femur and cruciate ligaments has not been previously investigated.

Methods: Ten skeletally mature cross-bred dogs (>25.0 kg) underwent retrograde reaming of the femur from 6.0 to 9.0mm, with an intercondylar entry portal. Before and fifteen minutes after reaming, blood flow was measured using laser Doppler flowmetry (LDF) at three bone sites in the distal femur (trochlear groove, medial condyle, lateral condyle), and at the anterior and posterior cruciate ligaments.

Results: There were no complications in any of the animals, and at no time during the experiment did any animal experience hemodynamic instability. A significant increase in the mean post-reaming red cell flux was noted at all of the bone sites of the distal femur compared to pre-reaming values- intercondylar groove, (p=0.0247), lateral condyle, (p=0.0042), and medial condyle, (p=0.0446). There was a significant decrease in the mean post-reaming red cell flux at both cruciate ligament sites compared to pre-reaming values, anterior cruciate, (p=0.0004), and posterior cruciate, (p=0.0006).