Articular Cartilage Changes Seen With Magnetic Resonance Imaging-Detected Bone Bruises Associated With Acute Anterior Cruciate Ligament Rupture

Abstract

Occult osteochondral lesions (bone bruises) have been documented on magnetic resonance images in more than 80% of patients sustaining acute anterior cruciate ligament ruptures. Despite the high prevalence of these lesions, little is known about the histologic changes in the adjacent articular cartilage. Ten patients with acute anterior cruciate ligament ruptures who had a preoperatively documented (by magnetic resonance imaging) geographic bone bruise at the sulcus terminalis on the lateral femoral condyle underwent a 3-mm diameter trephine biopsy of the articular cartilage and subchondral bone overlying the bone bruise at the time of anterior cruciate ligament reconstruction. Biopsy samples of the articular cartilage and subchondral bone were stained with hematoxylin and eosin and toluidine blue. All patients had significant arthroscopic and histologic articular cartilage irregularity in the area overlying the bone bruise. Arthroscopic findings of the articular cartilage included softening (dimpling), fissuring, or overt chondral fracture. Histologic examination revealed degeneration of the chondrocytes and loss of toluidine blue staining in the articular cartilage (loss of proteoglycan). There was necrosis of osteocytes in the subchondral bone, and empty lacuna were visible. This study defines the exact histologic changes of the articular cartilage overlying a geographic bone bruise secondary to an acute anterior cruciate ligament tear. Our findings suggest that a geographic bone bruise found on magnetic resonance imaging indicates substantial damage to normal articular cartilage homeostasis.

BMP‐7 protects against progression of cartilage degeneration after impact injury

“…1 The relationship of previous injury to the development of knee OA has been established by meta-analyses and case series [2][3][4] showing progressive cartilage loss or ''chondropenia'' 5 that may arise from compromised chondrocyte viability. [6][7][8] Strategies that prevent cartilage degeneration in the posttraumatic knee would be very valuable. Although there is experimental evidence that this goal may be attainable, [9][10][11][12][13][14][15] recent reviews of OA treatment strategies in clinical trials concluded that definitive evidence for disease modification in OA is scant.…”

The Health and Structural Consequences of Acute Knee Injuries Involving Rupture of the Anterior Cruciate Ligament

“…Johnson et al found significant proteoglycan loss, chondrocyte injury and matrix degeneration in the articular cartilage adjacent to a geographic BML, as well as osteocyte necrosis within the affected bone marrow 32 . A separate follow-up study by Theologis et al found that the matrix composition in cartilage overlying bruises in the lateral tibia was still abnormal one year post-injury despite most of the original osteochondral lesions healing almost completely within 2 weeks to 6 months 18 .…”

“…Direct cartilage damage is associated with short-term matrix disruption, chondrocyte necrosis and proteoglycan loss 32 . Though it is not yet known whether these changes are ultimately reversible, or become irreversible if a certain amount of damage is sustained, it is possible that the initial trauma plays a role in instigating the well-described progressive cartilage loss that is characteristic of osteoarthritis 18,32 .…”

“…It has previously been postulated that frequent episodes of instability or pivot-shifting could result in sustained damage to both the articular cartilage and menisci that eventually results in loss of the cartilage 51 . The extent to which cartilage must be damaged in the initial trauma before structural damage becomes irreversible is not yet known, but it is possible that the regular occurrence of instability-related trauma and altered biomechanical loading could overwhelm the limited restorative capacity of the joint and lead to longer-term osteoarthritic changes 32 . Concurrent injury to the menisci and the corresponding loss of its protective function would merely serve to exacerbate the damage to articular cartilage 34 .…”

Effect of intermittent cyclic preloads on the response of articular cartilage explants to an excessive level of unconfined compression

“…1 In cases of knee ligament injury, early detection of bone bruises is seen in over 80% of cases. 2,3 These lesions have also been observed in clinical cases without acute ligament or osteochondral damage. 4 Recently investigators 3,5 documented early degeneration of overlying articular cartilage and chondrocyte death with these bone lesions.…”