Arthrodesis

Arthrodesis is the surgical fusion of two joints in the body. The goal is to fuse the joint in order to remove bone-bone friction and/or nerve compression that cause pain and other symptoms. The method can be used to treat ailments within nearly any joint in the body, but is most commonly used for pain in the hips, ankles, wrists, fingers, thumbs or spine. Arthrodesis is used in patients whose joints have been impaired by arthritis such as osteoarthritis or rheumatoid arthritis.

Conditions within the spine that often are treatable through arthrodesis include:

• Spinal arthritis
• Degenerative disc disease
• Spinal stenosis
• Spondylolisthesis
• Facet disease

These degenerative spine conditions can give rise to localized pain caused by the exposure of bone in the presence of frayed joint cartilage, as well as anatomical abnormalities such as bone spurs and herniated discs. Nerve compression can cause shooting pain, tingling, numbness or muscle weakness in the extremities. These symptoms typically can be managed using conservative, nonsurgical methods, but if symptoms persist after several weeks or months, spinal arthrodesis may be recommended.

Surgeons perform spinal arthrodesis to relieve joint pain that has been unmanageable through methods such as bracing, ingesting over-the-counter or prescription anti-inflammatories or analgesics, or splinting. The pain can be caused by injury, such as a broken finger or ankle, or by an age-related degenerative condition, such as osteoarthritis.

The basic idea is to encourage the fusion of the joints in desired position and hold the bones till the fusion is strong enough to hold itself together without the need of either internal or externalimplant.Arthrodesis is achieved by positioning bone graft to induce the process of fusion while the bone is held securely by internal or external fixation. Itaims at eliminating pain arising due to arthritis, stabilizing joint that is either unstable, and removing an infectious lesion in arthritis, thereby eliminating motion in the fused joint. The operation involves removal of joint cartilage and immobilization; and a bone transplant may be used for faster restoration.

Minimally invasive procedures also are all performed on an outpatient basis and offer a lower risk of infection and complication than traditional spinal fusion.While a fused joint loses flexibility, it can bear weight better, is more stable and is no longer painful.

Procedure

There are different ways to perform arthrodesis surgery:

• A bone graft is placed in between the two bones being fused to stimulate the fusionusing a bone from elsewhere in the person's body (autograft) or using donor bone (allograft) from a bone bank.
• Implants of metal screws, plates or wires can be used to approximate the joint and position the bones next to each other. Over a period of time, the bones get fused.

Arthrodesis can be of following types

• Intra-articular- the joint surfaces are exposed and fused. It permitsgreater correction of any deformity
• Extra-articular- the joints are not exposed and the arthrodesis is achieved by producing fusing bone block outside the joint. Extra-articular techniques are useful in treating children as mostly joint surfaces are cartilage, and in treating patients with necrotic bone or active infection, as in tuberculosis.
• Combined intraarticular and extra-articular.

Complications

The risks associated with joint fusion vary depending upon factors like age, overall health status and the type of procedure that is performed. Few risks are enumerated below:

• Pain at the site of bone fusion
• Failure of the fusion and/or breakage of metal implants
• Nerve injury
• Infection

The main disadvantage of arthrodesis is that it reduces the movement of joint. Thus the function of the limb is definitely compromised.Therefore the arthrodesis is considered only in patients where the advantages outweigh the disadvantages.