Harvesting Articular Cartilage From Joints of an Equine Donor: A Surgical Procedure to Isolate Vascular Connective Tissue From Cadaveric Joints of an Equine Donor

The articular cartilage - a highly specialized avascular connective tissue covering the end of opposing bones in certain joints, facilitates load distribution to underlying subchondral bone. It is surrounded by synovial fluid, lubricating the surface for smooth joint movement.

To harvest the articular cartilage, begin with an intact equine cadaveric joint on a sterile platform. Remove the skin and any excess fat tissue surrounding the joint area of interest. Perform angular movements of the joint to identify the joint location.

Make horizontal and vertical incisions around the joint region. Remove the muscles and tendons - connective tissue that attaches muscles to bone - to reveal the joint cavity filled with synovial fluid. Incise through the connective tissue that holds the joint together to completely expose the joint. Visually inspect the articular cartilage for its glossy and smooth appearance, ensuring there's no damage.

Gently excise the articular cartilage from the subchondral bone, moistening the cartilage with a suitable buffer to prevent tissue drying. Wash the cartilage slices with antibiotic-containing buffer to eliminate microbial contamination.

Snap freeze the rinsed articular cartilage in liquid nitrogen-cooled isopentane to freeze it to ultra-low temperatures to preserve the integrity of tissue constituents. Freeze-dry the cartilage to remove water from the tissue. Store the freeze-dried cartilage slices at room temperature until use.

Obtain an intact cadaveric joint for cartilage isolation, and remove the skin, excess fat, and muscle tissue as described in the accompanying text protocol. Next, define the location where the joint articulates by performing extension and flexion of the joint. Make a horizontal incision to reach the joint cavity.

Next, make a vertical incision to open up the joint area. The joint cavity is filled with synovial fluid which will likely drip from the cavity when performing a correct incision. Continue to open up the joint completely by removing excessive fat, muscles, and tendons, and by cutting through the tendons that keep the joint together. Carefully inspect the cartilage for any macroscopic damage.

If the articular cartilage does not have a glossy or smooth appearance or, if evident blistering, clefts, or defects are present, discard the cartilage and start again.

Use a sterile scalpel to remove the cartilage from the bone. Cut all the way down to the subchondral bone to remove the deep-zone cartilage. Collect the removed cartilage slices in 50-milliliter tubes containing previously prepared cartilage washing solution. While being processed, regularly drip cartilage washing solution on the cartilage to prevent the cartilage from drying out.

After collecting the cartilage from all of the areas of interest, snap-freeze the cartilage slices in liquid nitrogen for five minutes. Then, transfer the cartilage slices into 50-milliliter tubes, and immediately placed the frozen slices in a freeze dryer. Lyophilize the cartilage slices for 24 hours with the freeze-dryer. When finished, store the freeze-dried cartilage slices in a dry place at room temperature.