Onset of preclinical osteoarthritis: the angular spatial organization permits early diagnosis.

Objective: Superficial articular chondrocytes display distinct spatial remodeling processes in response to the onset of distant osteoarthritis (OA). Such processes may be used to diagnose early events before manifest OA results in tissue destruction and clinical symptoms. Using a novel method of spatial quantification by calculating the angles between a chondrocyte and its surrounding neighbors, we compared maturational and degenerative changes of the cellular organizations in rat and human cartilage specimens.

Vulnerability of the superficial zone of immature articular cartilage to compressive injury.

Objective: The zonal composition and functioning of adult articular cartilage causes depth-dependent responses to compressive injury. In immature cartilage, shear and compressive moduli as well as collagen and sulfated glycosaminoglycan (sGAG) content also vary with depth. However, there is little understanding of the depth-dependent damage caused by injury.

Proliferative remodeling of the spatial organization of human superficial chondrocytes distant from focal early osteoarthritis.

Objective: Human superficial chondrocytes show distinct spatial organizations, and they commonly aggregate near osteoarthritic (OA) fissures. The aim of this study was to determine whether remodeling or destruction of the spatial chondrocyte organization might occur at a distance from focal (early) lesions in patients with OA.

Methods: Samples of intact cartilage (condyles, patellofemoral groove, and proximal tibia) lying distant from focal lesions of OA in grade 2 joints were compared with location-matched nondegenerative (grade 0-1) cartilage samples.

Distinct horizontal patterns in the spatial organization of superficial zone chondrocytes of human joints.

A better understanding of the unique cellular and functional properties of the superficial zone of articular cartilage may aid current strategies in tissue engineering which attempts a layered design for the repair of cartilage lesions to avert or postpone the onset of osteoarthritis. However, data pertaining to the cellular organization of non-degenerated superficial zone of articular cartilage is not available for most human joints. The present study analyzed the arrangement of chondrocytes of non-degenerated human joints (shoulder, elbow, knee, and ankle) by using fluorescence microscopy of the superficial zone in a top-down view.

Analysis of the relationship between peak stress and proteoglycan loss following injurious compression of human post-mortem knee and ankle cartilage.

While traumatic joint injuries are known to increase the risk of osteoarthritis (OA), the mechanism is not known. Models for injurious compression of cartilage may identify predictors of injury that suggest a clinical mechanism. We investigated the relationship between peak stress during compression and glycosaminoglycan (GAG) loss after injury for knee and ankle cartilages.