Femoral and Cruciate Blood Flow After Retrograde Femoral Reaming: A Canine Study Using Laser Doppler Flowmetry

OBJECTIVE:To determine the effect of retrograde femoral reaming on the blood flow of the distal femur and the cruciate ligaments. DESIGN:Canine experimental study. SETTING:Tertiary referral and teaching hospital in Toronto, Canada. PARTICIPANTS:Thirteen skeletally mature, cross-bred dogs. MAIN OUTCOME MEASURE:Red cell flux (RCF) was measured by using a laser Doppler flowmetry probe at three bone sites in the distal femur (trochlear groove, medial condyle, and lateral condyle) and at the midportion of both the anterior and posterior cruciate ligaments before and after retrograde femoral reaming. RESULTS:There was a significant increase in the mean postreaming RCF at all the bone sites of the distal femur compared with prereaming valuestrochlear groove (p = 0.0247), medial condyle (p = 0.0440), and lateral condyle (p = 0.0042). We also found a significant decrease in the mean postreaming RCF at both cruciate ligament sites compared with prereaming values (anterior cruciate, p = 0.0004; posterior cruciate, p = 0.0006). CONCLUSIONS:Retrograde femoral reaming and intramedullary nailing has become a popular option for the treatment of distal femoral and some femoral shaft fractures, but concerns regarding the effect of reaming through an intraarticular entry portal have been raised. Our experimental study found that after reaming perfusion of the anterior cruciate ligament decreased by 52 percent and perfusion of the posterior cruciate ligament decreased by 49 percent. Diminished perfusion after reaming may delay healing or exacerbate existing injury to the cruciate ligaments and adversely affect rehabilitation of the knee after femoral fracture.