Pilot Study of rhBMP-2/BCP in Patients With Spinal Degeneration With Instability Requiring Surgical Fusion

Inclusion Criteria: * Subject has radiographically documented spinal degeneration with instability as documented by the presence of translation \>= 4mm or angulation \>= 5°. * Subject has intractable back pain which does not respond to conservative treatment and in the investigator's opinion, requires surgical spinal fusion. * Subject's pain is predominantly associated with the back. * Subject has only one level involvement at L3-L4, L4-L5, or L5-S1. * Subject is 18 years of age or greater at the time consent is given to participate in the study. * Subject is willing to comply with the study plan and sign the informed consent. * Subject is male or a non-pregnant, non-nursing female. All females of child-bearing age must agree to use adequate contraception for a period of no less than 16 weeks following surgery. Exclusion Criteria: * Subject has primary spinal diagnosis of a disorder other than spinal degeneration with instability at the involved surgical level. * Subject has spinal stenosis or condition which requires a full laminectomy procedure. * Subject has had a previous fusion, discectomy or laminectomy procedure at L3-L4, L4-L5 or L5-S1. * Subject has received drugs which may interfere with bone metabolism within two weeks prior to the planned date of spinal fusion surgery (e.g., steroids, methotrexate) or has a condition which requires postoperative medications that interfere with fusion (e.g., steroids, nonsteroidal antiinflammatory drugs, or methotrexate). * Subj…