The goal of this clinical trial is to learn if using calcium sulfate beads that contain vancomycin (an antibiotic) and pain-relieving medicines during spine surgery can improve recovery compared to standard care with intravenous (IV) morphine and local pain medicines.

Researchers want to know if the sustained release formulation of morphine from these calcium sulfate beads affect:

• Postoperative length of stay
• Postoperative pain scores
• Postoperative narcotic analgesic requirements

All participants in this study will already be scheduled to have spine surgery as part of their regular medical care. During surgery, participants will be assigned to receive either intraoperative placement of calcium sulfate beads with vancomycin alone or vancomycin with morphine and bupivacaine. All patients will still have access to standard of care with IV and PO pain regimens. Participants will then be followed after surgery to measure their pain, recovery, and medication use.

Participation is voluntary, and choosing not to join will not affect a person's medical care.

Inclusion Criteria:

• Age ≥ 18 years
• Able to understand and provide consent in English
• Undergoing elective lumbar spinal decompression and fusion surgery at one or two levels

Exclusion Criteria:

• History of allergy or hypersensitivity to morphine, bupivacaine, or calcium sulfate.
• Active systemic or localized infection at the surgical site.
• History of chronic opioid dependence or opioid use disorder (as it may confound pain assessment).
• Patients with severe renal or hepatic impairment (due to altered metabolism of analgesics and risk of complications from analgesic side effects).
• Pregnant or breastfeeding individuals.
• Filling of defects that are intrinsic to the stability of the bony structure
• Severe vascular or neurological disease
• Uncontrolled diabetes
• Severe degenerative bone disease
• Hypercalcemia

De-identified individual participant data (IPD) underlying the primary and secondary outcome results (including demographics, pain scores, analgesic consumption, hospital length of stay, functional outcomes, and adverse event data) will be shared. No data containing direct identifiers will be provided.

IPD and supporting documents will be made available beginning 6 months after publication of the primary study results and will remain available for 5 years.

Access will be granted to qualified researchers affiliated with academic or healthcare institutions who provide a methodologically sound proposal for secondary analyses related to spine surgery outcomes, pain management, or infection prevention. Proposals will be reviewed by the Principal Investigator and research team. Upon approval, data will be shared via a secure, HIPAA-compliant institutional data-sharing platform. Requests should be directed to Ganesh Shankar (gshankar@mgh.harvard.edu).