Why it’s done: To correct a difference in leg lengths that may be caused by accelerated growth of the limb with arthritis.

What else you need to know: Epiphysiodesis usually is reserved for children whose anticipated leg-length discrepancy is greater than 2 centimeters (or almost an inch) and who have at least two years of growth remaining. The recovery period is brief, and there are few complications.

Joint fusion (arthrodesis): In this procedure, also called bone fusion, the surgeon removes the cartilage from the ends of two bones that form a joint and then positions the bones together and holds them immobile, often with a pin or a rod. Over time, the two bones fuse to form a single solid unit.

Why it’s done: Arthrodesis can correct joint deformity. It can make the joint more stable, help it bear weight better and relieve pain. It’s most likely to be done on specific joints, including the foot/ankle, hand/wrist and spine.

What else you need to know: Once a joint is fused, your child will never again be able to bend it. Fusing one joint can place stress on nearby joints and increase the risk of fracture in the bones that are fused.

Joint replacement (arthroplasty): This surgery involves removing a damaged joint and replacing it with an artificial joint made of metal, ceramics and/or plastics.

Why it’s done: Total joint replacement can often dramatically reduce pain and improve motion, mobility and function. It is usually reserved as the final option for joints that are so severely damaged, painful and stiff that they interfere with the child’s functioning and quality of life. The most commonly replaced joint due to JIA is the hip, followed by the knee; rarely is the ankle, wrist or shoulder replaced.

What else you need to know: Total joint replacement does have some drawbacks. Replacing joints can stunt growth, and the longevity of prosthetic joints is limited. Most doctors delay the surgery as long as possible for young people. Complications can include premature failure of the synthetic joint or an infection that could potentially necessitate additional surgery.

Synovectomy: This procedure removes excess synovial tissue. The synovium is normally a thin membrane that lines the joint capsule. With chronic inflammation of this lining (as occurs with juvenile arthritis), it not only produces extra fluid, but grows much thicker and can affect joint structure and function. The vast majority of synovectomies are performed by arthroscopy, a procedure in which surgical tools are inserted through a few small incisions, eliminating the need to open the joint.