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What is Cartilage Allograft?

Cartilage allograft (also called osteochondral allograft transfer or OATS) is an arthroscopic surgical procedure performed to replace damaged articular cartilage of the knee with the bone and cartilage of a cadaver donor (allograft).

Key statistics about Cartilage Allograft

  • Approximately 12% of the population suffer from cartilage defects in the knee[1]
  • 60% of patients who undergo knee arthroscopy are discovered to have cartilage defects[2]
  • 74-85% of patients who undergo cartilage allograft have significant improvement in knee pain after the procedure[3]

Expert Insights

The Goals of Treating Cartilage Injuries - Daniel Cooper, MD

Knee Anatomy

The knee joint is formed by three bones: the femur (thigh bone), the tibia (shin bone), and the patella (kneecap).

Articular cartilage covers the ends of the bones, helping with shock absorption and allowing the bones to glide smoothly against one another. Articular cartilage is made up of cells called chondrocytes.

3D rendering of the knee with colorized regions highlighting its major anatomical structures

Why is Cartilage Allograft performed?

Articular cartilage damage can expose the underlying bone, causing pain and affecting joint function as the knee moves. Cartilage allograft is performed to address cartilage injuries to the knee joint in order to alleviate pain and restore a smooth joint surface. This procedure can also prevent the progression of cartilage damage and delay knee replacement.

Cartilage allograft uses bone and cartilage from a human donor to replace damaged areas of articular cartilage, repairing the injury. In some cases, the patient’s own healthy bone and cartilage may be harvested and transplanted into the damaged area instead (cartilage autograft).

Who needs Cartilage Allograft?

Damage to articular cartilage of the knee typically is caused by overuse or injury.

Ideal candidates for the procedure have smaller regions of cartilage damage (no widespread osteoarthritis or rheumatoid arthritis), have normal knee alignment and stability, and are relatively young, active, and willing to commit to physical therapy.

How is Cartilage Allograft performed?

  • The surgeon will make small incisions around the knee joint and the arthroscope will be inserted into one of the incisions.
  • Saline solution is pumped into the joint to expand it and improve visualization.
  • Images from the arthroscope are sent to a video monitor where the surgeon can see inside the joint.
  • Any damaged tissue is removed from the injured cartilage and the surrounding area is smoothed.
  • A plug of bone and cartilage harvested from a human donor (allograft) is inserted into the region of injured cartilage.
  • Finally, the saline solution is drained, instruments are removed, and the incisions are closed using sutures.

How is Cartilage Allograft performed?

Risks associated with cartilage allograft may include:

  • Infection
  • Blood clots
  • Persistent knee swelling
  • Nerve or blood vessel damage
  • Graft failure

How long does it take to recover from Cartilage Allograft?

  • 24 hours after surgery
    Most patients are able to return home the same day as their procedure. A physical therapy routine will be established by the surgeon and physical therapist, and pain medication may be prescribed. Crutches will be provided to keep weight off the affected leg.
  • 2 weeks after surgery
    Any non-dissolvable sutures are removed and bruising and swelling begin to subside.
  • 4-6 weeks after surgery
    Most patients can walk with full weight on the affected leg and resume most daily activities.
  • 6-9 months after surgery
    Most patients are fully recovered from cartilage allograft.

How long does it Take to recover from Cartilage Allograft?

Cartilage allograft is a safe and effective procedure performed to treat mild to moderate areas of articular cartilage damage within the knee joint. For patients who meet eligibility criteria for the procedure, this treatment can provide significant improvement in knee function and persistent pain.

Song, S.J. & Park, C.H. (2019). Microfracture for cartilage repair in the knee: current concepts and limitations of systematic reviews. Annals of Translational Medicine. 7(3), S108.
Smoak, J.B., Kluczynski, M.A., Bisson., L.J., & Marzo, J.M. (2019). Systematic Review of Patient Outcomes and Associated Predictors After Microfracture in the Patellofemoral Joint. JAAOS: Global Research and Reviews. 3(11), e19.00151.
Valdivia Zúñiga, C.A. & De Cicco, F.L. (2022, August 1). Osteochondral Allograft. StatPearls (Internet). Retrieved February 8, 2023 from
Last edited on January 18th, 2024 4:59 pm