Healing of Cartilage

- See: Chondral Injuries:

- Discussion:

    - articular cartilage is avascular & is prevented from mounting a vascular  response when there is isolated cartilage injury;
          - absence of vessels w/ in cartilage imposes limitations on healing potential;
         - indeed, some traumatic defects in cartilage apparently never heal;
    - chondrocytes in articular cartilage are capable of cell division & are also capable of increased proteoglycan synethesis;
    - regeneration of cartilage is slow, & highest potential for growth occurs in the perichondrium which lies at the periphery of articular cartilage;
    - mechanisms of repair:
         - when articular cartilage is injured, the type of healing that will take place is influenced by the depth of the injury;
         - extrinsic healing:
              - dependent on a synovial reaction or subchondral bone being penetrated at the time of injury;
              - w/ subchondral injury, capillary injury forms a fibrin clot, which is then replaced by granulation tissue and fibrocartilage;
              - if defect is limited to cartilage, no blood vessels are disrupted, and inflammatory response is less intense than if injury extends through
                    cartilage into subchondral bone, as occurs in intraarticular frx;
         - intrinsic healing (isolated injury):
              - dependent on chondrocytes to synthesize a new matrix;
              - since cartilage is largely avascular, healing is dependent on diffusion of nutrients from synovial fluid;
              - potential for intrinsic healing appears somewhat limited;
              - isolated injuries to cartilage (which do not extend to subchondral bone heal  slowly and incompletely;

- Continuous Passive Motion:

    - continuous passive motion can promote healing of articular cartilage;
    - in joints treated w/ continuous passive motion, healed articular defects where as joints that were immobilized showed no healing

Treatment of deep cartilage defects in the knee with autologous chondrocyte transplantation.

Quantitation of chondrocyte performance in growth-plate cartilage during longitudinal bone growth.

Elaboration of neutral proteoglycanase by growth-plate tissue cultures

The viability of articular cartilage in fresh osteochondral allografts after clinical transplantation.

Characterization of aggregating proteoglycans from the proliferative, maturing, hypertrophic, and calcifying zones of the cartilaginous physis.

The induction of neochondrogenesis in free intra-articular periosteal autografts under the influence of continuous passive motion. An experimental investigation in the rabbit.

Passive motion: the dose effects on joint stiffness, muscle mass, bone density, and regional swelling. A study in an experimental model following intra-articular injury.

Mesenchymal Cell-Based Repair of Large, Full-Thickness Defects of Articular Cartilage.

Alternatives to Total Knee Replacement: Autologous Hamstring Resurfacing Arthroplasty

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Friday, June 1, 2012 11:05 am