How Many Surgical Options for Degenerative Spondylolisthesis?

1. Decompression: laminectomy, laminotomy (bilateral, or uni-lateral with bilateral decompression), laminoplasty, indirect decompression.
2. Fusion with or w/o instrumentation: posterolateral, PLIF, ALIF, Lateral fusion, TLIF.
3. Non-fusion: dynamic stabilization, inter-spinous process device (IPD).
4. Cage: cylindrical, rectangular (single or pleural); Materials: titanium, PEEK, carbon-fiber, tantalum, ceramic,
5. Graft materials: autograft, allograft, DBM, BMP, 
6. Did I miss anything..

The menu list goes on.