Cartilage Injury

Introduction

Cartilage injury is can occur with direct blows or impact, can be associated with other ligaments injuries or fractures. Treating cartilage injury is difficult because the cells, like brain cells, do not divide and therefore have limited ability to heal on their own.

Anatomy

All joints contain cartilage. The normal motion of joints is lubricated by fluid called synovial fluid made by the cells that line each of the joints. The end of the bones themselves are covered with a specific type of cartilage called hyaline cartilage. Motion between hyaline cartilage lubricated with synovial fluid is smoother than ice on ice. Defects in the cartilage decrease this smooth motion and can result in friction causing pain, swelling, and changes to the synovial fluid in the joint.

Cartilage Damage

As we go about our daily lives the cartilage in our joints can wear slowly and gradually, much like the tread on a tire. When the cartilage becomes thin this process results in osteoarthritis (which is one type of arthritis). Unfortunately, any injury to the joint, the underlying bone, or it’s surrounding ligaments can speed the otherwise gradual process. Not all cartilage injuries cause symptoms to occur and if the remainder of the joint is healthy some cartilage injury can be very well tolerated. However, when this interferes with activities of daily living or the ability to play sports then treatment is required.

Non-Operative Treatment

Goals are always to maximize non-operative treatments first. By optimizing strength, range of motion, and endurance symptoms can be relieved in a majority of cases. Physical therapy, medications, and injections as well as supplements and adjunctive therapies are all viable options in treatment of cartilage injury.

Physical therapy can be performed as either a guided home program or in conjunction with a dedicated physical therapist. Therapists have various modalities that can decrease pain and improve function and can tailor a home exercise program to fit your needs.

Non-steroidal anti-inflammatory medications can be beneficial for some patients but have risks. Long term use should be discussed with a doctor or health care provider.

Some supplements have shown promise in the treatment of cartilage injury. Common over the counter formulations include glucosamine and chondroitin sulfate. Other herbal medications from ayurvedic and Chinese medicine have shown effectiveness in large research trials, but more research is needed to determine which compounds are providing the effectiveness.

Acupuncture is an additional modality which has shown proven effectiveness for some patients. It is low risk and often has additional benefits related to stress relief and relaxation which are often associated with and can worsen pain from injury.

In some cases, braces can be useful to provide proprioceptive feedback and compression to reduce swelling. Bracing can be highly customized based on patient anatomy and the nature of the injury.

Injections

Corticosteroid Injections

Steroid injections decrease the pain and inflammation associated with cartilage injury and can be very effective in eliminating swelling. This is often a first line treatment because the procedure is simple, effective, and can be performed in the clinic with minimal discomfort and no restrictions after the injection. Steroid injections do not directly treat the injury itself but relieve the symptoms associated with it. Steroid injections can be repeated at intervals of 4-6 months but sometimes lose efficacy over time.

Hyaluronic Acid Injections (HA)

HA is a normal component of healthy joints and a primary part of the synovial fluid that promotes lubrication between cartilage surfaces. As stated above, in the injured joint there can be loss of these normal compounds

Platelet Rich Plasma (PRP)

PRP is a relatively recent treatment for articular cartilage injury. Rather than a drug or compound, PRP is a portion of the patient’s own blood that is concentrated and injected into the diseased area. This is done in a procedural area, but not in the clinic, and takes about five to 10 minutes to perform. Blood is drawn and placed in a machine which separates the parts of the blood and isolates the growth factors from the cells. The concentrated growth factors are then injected. There are no restrictions after PRP although localized soreness is common for the first several days and full effects may take up to 6 weeks. While early research is promising, this procedure may not be covered by all insurance plans. At Mammoth Orthopedic Institute we are actively researching PRP and you may be asked to participate in our research outcomes registry.

Surgical Treatment

Failure of non-surgical treatments is the primary reason for investigating surgical options. Given the current state of technology there is a wide array of procedures available, some of which are discussed below. Choosing an individual treatment plan is a complex process and involves a thorough understanding of the injury severity, its size and location, and the risks involved.

Microfracture

Microfracture was one of the first techniques developed for cartilage repair. The procedure can be performed all arthroscopically and involves use of a pick to create small holes in the bone underneath the damaged cartilage which releases stem cells and growth factors which can generate a scar cartilage. A small pick or a wire can be used the make the microfracture holes. Microfracture does not restore normal cartilage. Rehabilitation after microfracture requires 6 weeks of strict non-weight bearing and early aggressive range of motion. Microfracture is most often used for lesions which are either very small or very large.

Biocartilage

Biocartilage is an adjunct to microfracture. It is developed form donor cartilage and contains the important building blocks for creating new cartilage such as type II collagen, proteoglycans and additional growth factors. The theory is that the addition of these growth factors will improve the overall quality of tissue that is generated after a microfracture. Because it can be inserted with a small needle biocartilage can be useful in some hard to reach portions of damaged joints and on uneven surfaces within the joint. Rehabilitation is similar to microfracture

Osteochondral Autograft/Allograft Transplantation Surgery (OATS)

OATS is the only procedure currently that provides mature normal cartilage to replace the damaged cartilage. In autograft OATS the healthy cartilage is transferred from a part of the joint that sees little or no stress and the diseased tissue is transferred to where the healthy cartilage was taken from. This is useful for smaller cartilage lesions up to 1.5 cm. The advantage is that no allograft, or cadaver tissue, is required. The disadvantage is that in some cases problems can occur at the donor site where the healthy cartilage was harvested.

In allograft OATS, a cadaver donor is found which has a similar size and shape to the patients damaged tissue and the corresponding area from the healthy cadaver cartilage is transplanted into the patient’s cartilage defect. This is commonly used for larger areas, greater than 2 cm. The transplanted tissue includes both the bone (osteo-) and cartilage (chondral) from the donor. Rehabilitation after OATS in many cases can be accelerated compared to the previously mentioned techniques because the graft is more stable at the time of implantation. One disadvantage to allograft OATS is that it may take time to find a donor cadaver with similar anatomy to the patient.

Cartiform

Cartiform is a product that is harvested from cadavers as well and is similar to osteochondral allograft described above. The difference is that the bone portion of the Cartiform is extremely thin making the graft flexible and able to conform to different surfaces. Because of this feature, an exact size match is not required as is the case for allograft OATS. The Cartiform can be trimmed to fit the defect and then secured with sutures or suture anchors. The disadvantage in this case is that the graft does not have immediate stability and that some time is required to allow the graft to heal before initiating weight bearing.