Physiological and mechanical adaptation of periarticular cancellous bone after joint ligament injury

Physiological and mechanical adaptation of periarticular cancellous bone af ter joint, ligament injury. J Appl Physiol 90: 1083-1087, 2001.-The relatio n between blood flow and bone mineral density (BMD) of periarticular bone w as examined in an in vivo model of joint instability. Eighty mature New Zea land White rabbits were randomly assigned to experimental [anterior cruciat e ligament transection (ACLX)], sham-operated control, or age-matched norma l control groups. Experimental rabbits underwent unilateral transection of the right anterior cruciate ligament, and the nonoperated left [contralater al (Cntra)] limb was a within-animal control. BMD and blood flow to the per iarticular bone in the femoral condyles were assessed in each group at 2, 4 , 6, 14, and 48 wk postsurgery, using quantitative computed tomography scan ning and entrapment of colored microspheres. BMD was significantly lower (5 %) in the ACLX compared with Cntra limbs. Periarticular bone blood flow in the ACLX limbs was significantly greater than in the Cntra limb (29%) in th e early stages (6 wk) after injury. Up to 48 wk post-ACLX, a significant co rrelation was found between increased blood flow and decreased BMD in the p eriarticular bone of the femoral condyles in the ACLX limbs. This correlati on suggested that heightened blood flow may be linked to mechanisms of bone adaptation in joints after ligament injury.