The investigator hypothesizes intraoperative salvaged red blood cells are a poor substitute for allogenic packed red blood cell transfusions. In addition to providing inadequate resuscitation, salvaged red blood cells can increase the rate of complications, including postoperative electrolyte abnormalities, thrombocytopenia, anemia, and coagulopathy.

The goals of this study would therefore be to:

1. Determine the impact of intraoperative salvaged red blood cells on resuscitation and whether the return of salvaged red blood cells decreases the amount of intraoperative and postoperative allogenic packed red blood cell transfusions, both in terms of whether any allogenic blood product was provided and the number of units transfused during the hospital stay.
2. Compare complication rates and other secondary outcomes between patients who receive salvaged red blood cells versus those who did not, including infection, acute kidney injury, thrombocytopenia, liver injury, cardiac events, thrombotic events, pulmonary complications, length of hospital stay, discharge disposition, and 30-day readmission rates.
3. Determine if there's a threshold of transfused cell salvage blood that may be beneficial (e.g. <300ml) and avoids complications.

Inclusion Criteria:

• Patients >18 years of age undergoing adult thoracolumbar spinal deformity surgery as defined by one or more of the following radiographic criteria: 1) sagittal vertical axis > 15 cm, pelvic incidence (PI) minus lumbar lordosis (LL) > 25°, T1 pelvic angle > 30°, thoracic scoliosis > 70°, thoracolumbar/lumbar scoliosis > 50°, or global coronal alignment > 7 cm; 2) one or more of the following surgical criteria: posterior spinal fusion > 12 levels, 3-column osteotomy (3CO), or anterior-column reconstruction; or 3) age > 65 years and undergoing a minimum of 7 levels of spinal instrumentation surgery (geriatric criteria).

Exclusion Criteria:

• Patients with active spinal infection, neoplasm, acute trauma, neuromuscular etiology, syndromic scoliosis, prisoners, and pregnant patients