Articular cartilage degeneration after acute subchondral bone damage An experimental study in dogs with histopathological grading

Abstract

Background Subchondral fracture patterns and bone bruises have been described and some clinical studies have shown alterations in the initially healthy cartilage after such lesions.Methods and results After having performed cadaver studies, we created an animal model to produce pure subchondral damage without affecting the articular cartilage, under MRI control. We used 12 beagle dogs. For quantification of different degrees of staining, we used a grading of the sections by means of the HHGS (Histological-Histochemical Grading System) or Mankin score.Results In all cases, FLASH 3D sequences revealed intact cartilage in MRI after impact. The best detection of subchondral fractures was achieved in fat-suppressed TIRM sequences. Image analysis based on the HHGS showed changes in 10 of 12 samples, with a high degree of significance 6 months after the initial trauma. Correlation analysis showed loss of the physiological distribution of proteoglycans and glycoproteins in the different zones of articular cartilage. Subcategories "Structure", "Cells" and "Safranin-O Staining" also showed high significance, and the category "Tidemark Integrity" showed a tendency. Interpretation Our findings indicate that acute subchondral fractures are a predictor of degenerative changes within 6 months. Modifications and supplements to rehabilitation might be needed in cases with accompanying subchondral lesions, e.g. in ACL tears.

Early detection of biomolecular changes in disrupted porcine cartilage using polarized Raman spectroscopy

“…Similar results have been observed in other impact models. 16,[31][32][33] In contrast to the lack of evidence of histological changes using conventional modified Mankin score for the 15-MPa impacted cartilage, in this paper, a wide spectrum of biomolecular changes associated with cartilage damage can be observed early using the polarized Raman spectroscopy.…”

Cartilage oligomeric matrix protein and matrix metalloproteinase-3 expression in the serum and joint fluid of a reversible osteoarthritis rabbit model

“…Its clinical manifestation includes slow development of joint pain, stiffness, tenderness, joint swelling, joint deformity, and restricted movement (Lahm et al, 2004;Fernandes et al, 2007) OA is a common joint disease with the main pathological process being articular cartilage matrix degradation. The critical factor of OA disease development is the change in cartilage cell metabolism.…”

Rehabilitation of Articular Lesions in the Athlete's Knee

“…Subchondral fractures should be included in the equation for risk of arthritis, 43 even in the absence of any initial intraarticular damage. 55 Several authors 30,34,43,44,82,90,91 have reported a high incidence of bone bruises, ranging from 70% to 85% in patients who sustain a ACL injury. These patients may exhibit greater symptoms and worse function than those with isolated ACL injuries.…”

“…3 Injury to the articular cartilage and subchondral bone can induce early changes of posttraumatic degenerative disease 68 and acute subchondral fractures have been shown to be a factor for future degenerative changes in animal studies of cartilage, even in the absence of any initial intra-articular damage. 55 Therefore, a geographic bone bruise is an important variable to include in the equation for risk of arthritis. 43 Chondral and osteochondral lesions are frequently associated with other intra-articular disorders.…”

“…21 Thus, controlling weight-bearing loads during all aspects of the rehabilitation program should be considered by the clinician, especially if the lesion is located on a weight-bearing portion of the knee joint. 43,55,68 We recommend developing a progressive weight-bearing program based on the extent and location of the lesion. Some patients may be placed on crutches for as short as 2 weeks and others as long as 8 weeks following an injury to the joint.…”