Arthrodesis (Joint Fusion) - What Arthritis Patients Should Know

Surgery Provides Pain Relief and Stability

A group of surgeons.
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Surgery is regarded as a "last resort treatment option" for joints severely damaged by arthritis. While joint replacement surgery has become an increasingly common procedure, especially for certain joints, not all affected joints are candidates for replacement. Arthrodesis, also known as joint fusion, may be more suitable for ankles, wrists, thumbs, toes, fingers, and the top vertebrae in the neck.

The ends of two bones are fused together in arthrodesis with screw fixation and possible bone grafting, depending on the condition of the bone. Reasons for considering the surgical procedure include: joint instability, severe joint damage caused by injury or disease, and pain with movement of the joint. The goal of arthrodesis is pain relief and regained stability and strength. The bones are aligned in the most functional position, but do lose their natural motion. I have compiled answers to some of the most frequently asked questions about arthrodesis.

Question: What makes ankle fusion preferable over total ankle replacement?

Answer: In theory, ankle replacement should be preferable over ankle fusion since motion would be preserved. Relief from pain and regained stability are attainable with both procedures. There has been concern about the failure rate of ankle replacement prostheses. There is, however, an 85% success rate with ankle fusion in rheumatoid arthritis patients.

Question: Is radiographically visible joint destruction necessary before a fusion is done? At what stage in the progression of arthritis is it best to have a fusion done?

Answer: Yes. Fusion is done as a last resort after medications and pain treatment regimens produce unsatisfactory results. The extreme pain which justifies fusion surgery is felt when bone rubs on bone after cartilage has significantly worn away.

There would certainly be x-ray evidence of such destruction.

Question: Does the fusion really alleviate all the pain?

Answer: It should. The best result is obtained if there are no complications and if the surgeon is proficient with a high success rate, ideally having done the procedure many times. Failure to place the ankle in the "optimal position" could lead to a poor clinical result.

Question: How much motion is sacrificed for pain relief?

Answer: Essentially all. The joint is placed in a fixed position. If the ankle is fused in the optimal position, some compensatory increase in motion can be expected at the midtarsal joints. Rocker bottom shoes are usually recommended to compensate for loss of motion, if the patient feels the need.

Question: How long does the patient have to be non-weightbearing after an ankle fusion?

Answer: For 6 to 12 weeks, the patient must be non-weightbearing. Unprotected weightbearing can begin only after some bone striation is visible on x-ray at the site of fusion.

Question: After the pins are removed how long do you have to be in a cast?

Answer: The average immobilization time until all casts are removed is between 4 and 7 months. The pins are not removed if the internal fixation operative technique is used. There also are external fixation techniques, as well as arthroscopic arthrodesis.

Question: What are some of the complications of having a joint fusion?

Answer: As with any surgery, infection is a possible complication, as well as wound dehiscence (splitting open at the incision line). A failed fusion is also a possibility, whereby the bone ends do not completely fuse despite fixation. A condition known as osteopenia may compromise fixation.

Question: Is it harder to walk barefoot compared to walking with shoes after an ankle fusion?

Answer:. For patients with a well-aligned ankle fusion, the walking gait in an appropriate shoe (obviously high-heels are out!) is nearly normal. The gait may appear to be more stiff, but that is usually subtle, and it feels normal. Running or walking on uneven ground is made more difficult.

Question: What about fusion in the toes and the fingers? Is this a difficult operation and does it bring relief from pain and increased use of the joints?

Answer: Fusion is not regarded as a difficult operation, but the period of recuperation is long and arduous. As with the ankle or any joint being fused, motion is sacrificed for pain relief and stability. Some function can possibly be restored with the increased stability.

Question: After a wrist fusion, how much movement is available? Can one still write and type?

Answer: The ability to write or type would depend largely on the individual and the condition of their fingers. The motion for writing and typing comes mostly from the fingers.

Sources:

Ankle Arthrodesis. Wheeless Textbook of Orthopedics. Last Updated August 12, 2015.
http://www.wheelessonline.com/ortho/ankle_arthrodesis

Kelley's Textbook of Rheumatology. Ninth edition. Elsevier. Foot and Ankle Pain. Arthrodesis. Pages 705-706.

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