A longitudinal study of subchondral plate and trabecular bone in cruciate‐deficient dogs with osteoarthritis followed up for 54 months

Abstract

Objective. To evaluate the sequence of changes in articular cartilage, trabecular bone, and subchondral plate in dogs with osteoarthritis (OA), 3 months, 18 months, and 54 months after anterior cruciate ligament transection (ACLT).Methods. Specimens of the medial tibial plateau Submitted for publication May 5 , 1992; accepted in revised form February 9, 1993. were analyzed with microscopic computed tomography (micro-CT) at a resolution of 60 pm, and biochemical and morphologic changes in the femoral articular cartilage were assessed.Results. At 3 months and 18 months after ACLT, the articular cartilage in the unstable knee showed histologic changes typical of early OA and increased water content and uronic acid concentration; by 54 months, full-thickness ulceration had developed. Micro-CT analysis showed a loss of trabecular bone in the unstable knee, compared with the contralateral knee, at all time points. Al. both 18 and 54 months, the differences in trabecular thickness and surface-tovolume ratio were greater than at 3 months. Although the mean subchondral plale thickness, especially in the medial aspect of the medial tibial plateau, was greater in the OA knee than in the contralateral knee 18 months and 54 months after ACLI', these differences were not statistically significant; however, the difference was significantly greater at 54 months than at 3 months.Conclusion. Thickening of the subchondral bone is not required for the development of cartilage changes of OA in this model. The bony changes that develop after ACLT, however, could result in abnormal transmission of stress to the overlying cartilage and thereby contribute to the progression of cartilage degeneration.In the pathogenesis of osteoarthritis (OA), interactions among all the major joint tissues, including the articular cartilage, synovium, and subchondral bone, have been implicated (1). While a large body of work has focused on the alterations in the articular cartilage in OA in humans and experimental animal

Quantitative MRI of cartilage and bone: degenerative changes in osteoarthritis

“…In the guinea pig, Layton et al (218) observed that an initial loss of trabecular bone volume fraction, and thinning of trabeculae in early OA was followed by an increase of trabecular bone volume fraction and trabecular thickening in the advanced stages of OA. In a canine ACL transection model of OA, Dedrick et al (220) demonstrated an increase in subchondral bone thickness, accompanied by a decrease in trabecular thickness. Using magnification radiographs in humans, Lynch et al (205) observed an increase in the horizontal trabecular thickness of the tibia in early OA, followed by an increase in vertical connectivity of trabeculae in advanced OA.…”

“…Based on mCT findings in experimental models of OA, it has been suggested that changes in articular cartilage that occur in OA are associated with changes in the adjoining subchondral and trabecular bone (218)(219)(220). In the guinea pig, Layton et al (218) observed that an initial loss of trabecular bone volume fraction, and thinning of trabeculae in early OA was followed by an increase of trabecular bone volume fraction and trabecular thickening in the advanced stages of OA.…”

Osteoarthritis: Is it a disease of cartilage or of bone?

“…When cartilage loss started, the subchondral plate and trabeculae underneath cartilage were thin; only later in OA development did the radiographic equivalent of "eburnation" occur with thickening of both areas of bone. These experiments were later replicated in dogs (10). While studies of humans with OA usually focus on those with later-stage disease, at a time when cortical thickening would be expected (11,12), one study of knees from those with fissuring of cartilage but no denudation showed the cartilage bone plug to be less stiff than in unaffected knees of age-matched subjects (13).…”

Similarities and discrepancies in subchondral bone structure in two differently induced canine models of osteoarthritis

“…In established OA, studies of bone of existing noninvasive (in vivo) analytic methods of subchondral bone changes is low, and small changes are difficult to quantify. (8) Several studies in the rabbit and canine anterior cruciate ligament transaction (ACLT) model of OA (9) showed a decrease of trabecular bone volume (10)(11)(12)(13) and a thinning of the subchondral plate (13)(14)(15) early in the disease process. These changes are in contrast to those found in human end-stage OA.…”