Cartilage Restoration

Osteochondral Allograft Transplantation

Osteochondral allografting has a long and successful history and is becoming increasingly popular in the field of cartilage restoration

Who is a candidate for this procedure?

The typical individual considered a candidate for fresh osteochondral allografting is a younger, more active individual with a symptomatic, disabling cartilage injury or disease present in the knee, ankle or other joints such as the shoulder. Candidates are generally under 50 years of age and have a diagnosis such as traumatic chondral or osteochondral injury, osteochondritis dissecans, avascular necrosis, post traumatic arthrosis, focal secondary arthrosis, or patella femoral problems. Often, individuals have failed other forms of treatment, or felt to have disease states which are not amenable to any other type of procedure. Osteochondral allografts are particularly suited for osteochondral lesions such as Osteochondritis Dissecans, focal osteonecrosis or periarticular trauma where bone deformity or deficiency occurs in association with chondral disease.

Common Reasons for Osteochondral Grafting

1. Chondral and osteochondral lesions grater than 22 cm
2. Revision or salvage of previous cartilage surgery
3. Osteochondritis dissecans type III or IV
4. Osteonecrosis
5. Post traumatic reconstruction after a fracture

Candidates for the procedure are first evaluated with a careful history and clinical examination as well as documentation of the size and type of lesion within the knee. This either includes an arthroscopic photo or video, or a MRI, along with plain radiographs. At this point, if the individual is felt to be a candidate, a radiograph is obtained and the size of the knee joint is determined. The individual is then placed on a waiting list. Donor tissue is obtained from an accredited tissue bank that specializes in the complex process of recovering and preparing fresh, living osteochondral tissue. The tissue is transplanted fresh (usually within 28 days of recovery), not frozen or processed like other tissue allografts. This allows for the cartilage cells to survive and maintain the transplanted cartilage tissue. No tissue type matching is performed because the allograft is felt to be only minimally immunogenic. Donor recipient matching is done primarily by size to ensure optimum fit of the allograft. When a donor becomes available and is matched to the appropriate recipient, this individual is contacted and sheduled for the surgical procedure, preferally within 48-72 hours. The procedure is 1-3 hours in length and essentially consists of replacing the damaged joint surface with with a carefully fitted graft from the donor tissue. Typical hospitalization is zero to three days and there is a period of protected weight bearing and physical therapy for up to three months. Patients are encouraged to complete a therapy program, including a range of motion and muscle rehabilitation

Surgical Technique Summary

  • Available instrumentation can harvest grafts between 10 and 35mm in diameter
  • Osteochondral allografting is performed through a mini or standard arthrotomy
  • The defect is exposed and sized. A guide pin is placed through the center of the lesion, perpendicular to the joint surface
  • The lesion is reamed to a modest depth removing diseased cartilage and 3-6mm of bone
  • Depth measurments are taken from the prepared recipient site
  • The allograft plug is removed from the donor tissue utilizing a coring reamer
  • Recipient depth measurments are marked on the plug and excess bone is removed, creating an osteochondral graft matching the size and depth of the prepared recipient site
  • The graft is lavaged to remove blood and debris and bony edges are trimmed to facilitate insertion.
  • The graft is gently inserted with a tamp or joint compression during range of motion
  • Losse grafts are fixed in place with absorbable pins or screws
  • Cost of Procedure and Insurance Issues

    Insurance issues are a concern quite frequently because the procedure is uncommon and unfamiliar to many insurers. Therefore, many insurers feel that this is an experimental procedure and initially will not approve it. However, after documentation of efficacy (based on scientific studies) and an explanation of the unique nature of the procedure and lack of alternatives for individuals who are typically quite disabled and have a very poor prognosis for their knee the procedure will typically be approved. The allografting procedure is often done in specialized centers or by experienced surgeons, where the complex requirements of procurement of allograft material, preparation and technical aspects of performing the surgery have been established. The total cost of this procedure is very comparable with knee replacement or other cartilage repair techniques, including the surgical cost, the hospitalization, and the cost of the donor tissue.

    ** Tips for getting the procedure approved **

    Figure 1. Medial femoral condyle of a knee joint with cartilage damage caused by osteochondritis dissecans.
    Figure 2. Allograft tissue prior to preparation of the graft.
    Figure 3. The damaged area has been prepared to accept the allograft transplant.
    Figure 4. The allograft tissue has been inserted into the knee joint and the damage is repaired.