OsteoFlo HydroFiber Ambispective Evaluation

Inclusion Criteria: * Skeletally mature and age ≥ 18 years of age at the time of surgery. * Previously implanted with OsteoFlo HydroFiber in one or two contiguous vertebral level(s) in the lumbar (L1-S1) spine. * OsteoFlo HydroFiber was mixed with saline, blood, or bone marrow aspirate prior to use in the index procedure. * Be 6-months (180 -10/+30 days) post-surgery at the time of informed consent and at the6-month visit. * Be willing and able to comply with the study protocol requirements. * For prospective visit cohort, be willing to sign the study-specific Informed Consent Form. Exclusion Criteria: * Use of other bone graft substitute such as but not limited to, allograft, DBM, rhBMP-2 orsynthetic peptide enhanced graft as part of the index surgery. * Any lumbar fusion or total disc replacement (TDR) prior to the index procedure. * Any hardware failure prior to enrollment (e.g., cage, screw, or rod migration, loosening, or breakage) as determined by the core imaging lab. * BMI \>40. * Nicotine or recreational drug use at the time of the index surgery or during the healing period. * Significant metabolic bone disease (e.g., diagnosis of osteoporosis or osteomalacia). * Any active systemic or local spine infection at the time of surgery. * History of spinal infection at any spinal level prior to the index surgery. * Chronically taking medications that are known to interfere with bone healing (e.g., steroids) perioperatively and during the bone healing period. * Current active or suspected malignancy, or a cancer diagnosis that was ongoing during the patient's treatment and healing period. * Currently enrolled in a competing research study. * Currently incarcerated. * Unable to comply with all postoperative imaging requirements (e.g., pregnant or nursing).