Since 1982, 21 patients were operated at our hospital including 12 males and 9 females. The average age were 59.4 years, the average duration of HD was 15.5 years, and DSA was in the cervical spine in 14 cases, and the lumbar spine in 7. Symptoms were pain in 21 patients (100%) and neurological deficits in 19 (90%). Histological examination of respected specimen revealed amyloid deposits in all cases.

We classified the X-rays changes from DSA in stage 0 (no change) to stage 3 (end stage), and as type A (kyphosics), B (subluxation), C (amyloid deposits in soft tissues), and D (spontaneous fusion).

All 21 cases were classified as stage 3. The 14 cervical spine cases belonged to type A or B, but all 7 lumbar spine cases belonged to type C or were combined types.

In the 14 cervical spine cases, spinal fusion was done to stabilize the spine (AO plate in 3, Axis plate in 2, Olerud system in 2, and others in 7).

In contrast, posterior decompression (laminoplasty with or without spinal fusion) was done in all 7 lumbar spine cases.

The results were evaluated from the JOA scores. The score improved from 6.1 to 10.1 points (full score:17) in cervical patients and it improved from 12.2 to 20.2 points (full score:29) in lumbar patients. One patient died 2 days after surgery because of massive blood loss.

Twenty-one operations for DSA were investigated. Surgical strategies were decompression, stabilization, or combination. In addition, minimum invasive procedure should be considered for the patients with high-risk and the poor bone quality.