A nonunion is a fracture that has not healed. When this happens in the scaphoid, the bone is hollowed out by a cyst, and collapses in shape. This is called a humpback deformity.

A nonunion is often painful, and cause wrist weakness and stiffness. With time the change in loads and mechanics results in arthritis.

Surgery is the only option to get the bone to heal. This requires a bone graft to fill the cyst and correct the shape back to its original form. Often this can be done by minimally invasive arthroscopic techniques to clean out the cyst and fill the cavity with morsels of bone graft, followed by fixation with a screw.

The bone graft can come from the ridge of bone of the pelvis called the iliac crest.

If there is a lack of blood getting to part of the scaphoid, or the nonunion is in the part of the bone called the proximal pole, the bone graft is better to have its own blood supply, a vascularised bone graft.

A vascularised graft can come from the front or back of the radius bone, or from the knee.

Surgery for nonunion is not guaranteed of success. Some bones still do not heal. If there is early or advanced arthritis, other surgical procedures are better able to solve pain problems but do result in less movement.