Four corner fusion

Four Corner Fusion (4CF) is a surgical procedure used to treat advanced wrist arthritis, particularly following the collapse of the scaphoid bone, a condition known as scapholunate advanced collapse (SLAC) or scaphoid nonunion advanced collapse (SNAC). The procedure aims to alleviate pain while maintaining a functional range of motion in the wrist by fusing the four bones in the wrist's proximal row, excluding the scaphoid.

Indications

Four Corner Fusion is indicated for patients with SLAC or SNAC wrist, characterized by significant pain and functional impairment due to arthritis. It is typically considered after conservative treatments, such as splinting, anti-inflammatory medications, and corticosteroid injections, have failed to provide relief. The procedure is also an option for patients with Kienböck's disease in advanced stages, where the lunate bone has collapsed.

Procedure

The surgery involves the removal of the arthritic scaphoid bone and the fusion of the remaining four bones in the proximal carpal row: the lunate, capitate, triquetrum, and hamate. This is achieved using bone grafts and fixation devices, such as screws or plates, to promote bone growth and stability across the fusion site. The goal is to reduce pain by eliminating motion between the arthritic surfaces while preserving some wrist motion, particularly the ability to flex and extend.

Recovery

Postoperative recovery includes immobilization of the wrist in a cast or splint for a period, typically 6 to 8 weeks, to allow the bones to fuse properly. Physical therapy is an essential part of the recovery process, focusing on regaining wrist motion, strength, and function. Full recovery and return to normal activities can take several months.

Complications

As with any surgical procedure, Four Corner Fusion carries risks, including infection, nerve damage, nonunion (failure of the bones to fuse), and decreased wrist motion. There is also a risk of developing arthritis in the joints adjacent to the fusion site over time.

Outcomes

Studies have shown that Four Corner Fusion can effectively reduce pain and improve wrist function in patients with SLAC or SNAC wrist. However, the success of the procedure depends on several factors, including the extent of pre-existing arthritis, patient compliance with postoperative rehabilitation, and the surgeon's experience.

See Also

• Wrist Arthritis
• Scapholunate Advanced Collapse
• Scaphoid Nonunion Advanced Collapse
• Kienböck's Disease