The effect of a geographic lateral bone bruise on knee inflammation after acute anterior cruciate ligament rupture

We prospectively evaluated 40 patients who had knee inflammation after isol ated anterior cruciate ligament rupture with or without an associated "geog raphic" bone bruise/subchondral fracture of the lateral femoral condyle. Al l patients with acute ruptures documented by magnetic resonance imaging wit hin 1 week of injury were evaluated for a geographic bone bruise/subchondra l fracture of the lateral femoral condyle. Two groups of 20 patients each ( bone bruise versus no bone bruise) were then enrolled. Variables measured a t 1, 2, 3, and 4 weeks after injury included pain, range of motion, effusio n, and number of days with an antalgic gait. Patients with a bone bruise ha d increased size and duration of effusion, increased number of days require d to nonantalgic gait without external aids, increased days to achieve norm al range of motion, and increased pain scores at measured time intervals. T his study confirms results of previous clinical and histologic studies show ing an associated articular cartilage lesion, otherwise known as bone bruis e/subchondral fracture, is clinically significant. There appears to be an a ssociation between a geographic bone bruise and increased disability in pat ients with acute anterior cruciate ligament ruptures. Patients with a geogr aphic bone bruise may require longer to reach normal homeostasis (range of motion, pain, neuromuscular control) before undergoing anterior cruciate li gament reconstruction.