This study is a randomized controlled trial of preoperative oral iron supplementation, to identify whether iron deficiency is a modifiable risk factor for adverse surgical outcomes such as red blood cell transfusion and diminished postoperative cognitive and physical capacity in adolescents undergoing scoliosis surgery.

Research Question(s)/Hypothesis(es):

Primary

• Iron supplementation will reduce the incidence of perioperative RBC transfusion in iron deficient scoliosis patients undergoing spinal fusion.

Secondary

• Iron supplementation will reduce postoperative neurocognitive functional declines in iron deficient scoliosis patients undergoing spinal fusion.
• Iron supplementation will improve patient-reported physical functioning in iron deficient scoliosis patients undergoing spinal fusion.

Adolescents undergoing spinal fusion surgery for scoliosis are poised to benefit from preoperative iron supplementation. Spinal fusion carries a risk of large surgical blood losses and perioperative red blood cell transfusion, which are associated with adverse outcomes in this population. These patients are mostly adolescent females, a group more susceptible to iron deficiency and resulting anemia at baseline due to iron losses with menses, and who suffer an additional insult to iron stores during surgery. Nevertheless, iron status is not routinely monitored in this setting and there is no standard of care for preoperative iron supplementation. Iron is a nutritionally essential trace element important not only for red blood cell production, but also for muscle function and neurotransmitter synthesis and signaling. Therefore, the treatment of preoperative iron deficiency is an important target for optimizing hemoglobin prior to surgery, reducing transfusion rates and associated complications such as alloimmunization, and improving patient outcomes. On its own and as the primary cause of anemia, iron deficiency was identified by the investigator's team as the only risk factor for transfusion which is modifiable preoperatively.

In addition, iron supplementation is shown to alleviate impairments of physical and cognitive capacity associated with even mild forms of iron deficiency in adolescent females. A pilot study conducted at the investigator's institution identified iron deficiency in 36% of scoliosis patients prior to surgery, with preoperative iron status highly correlated with iron status during surgical recovery. Consequently, the investigator plans to examine iron deficiency as a modifiable risk factor for transfusion and impaired postoperative cognitive and physical capacity in this vulnerable population. Previous trials of brief iron interventions in high-risk adult surgical patients, mostly with unknown iron status, do not inform the care of iron deficient adolescents and were not designed to address postoperative functional outcomes. This study will therefore perform a single-center randomized controlled trial in which adolescents with scoliosis will be screened for iron deficiency (n = ~275), and iron-deficient adolescents with scoliosis (n = ~90) will be randomized to a preoperative regimen of daily oral iron or placebo, to test the hypotheses that preoperative iron supplementation 1) reduces the rate of red blood cell transfusion, 2) improves postoperative neurocognition compared to a preoperative baseline, and 3) improves patient-reported physical functioning during recovery. Results will ultimately improve outcomes in this vulnerable pediatric population and provide evidence for patient blood management approaches to reduce transfusions amid recent severe blood shortages.

Inclusion Criteria:

1. 10-26 years old;
2. diagnosis of scoliosis or kyphosis;
3. self-reported ability to swallow a tablet;
4. spinal fusion procedure planned approximately 6 to 24 weeks from an orthopedic surgical clinic visit at which patient agrees to phlebotomy for screening blood work;
5. serum ferritin less than or equal to 25 µg/L.

Exclusion Criteria:

1. taking or planning to take iron-containing supplement on patient's own volition, and not willing to stop for duration of study;
2. taking or planning to take iron-containing supplement as prescribed or recommended under the care of a physician;
3. Hg <10mg/dL if post-menarchal, Hg < 11 if premenarchal or male
4. C-reactive protein > 10 mg/L
5. receiving nutritional support by report in the medical chart;
6. self-reported history of hypersensitivity reaction to iron-containing supplements;
7. self-reported history of or suspected non-iron deficient hematologic disorder;
8. self-reported history of iron overloaded state such as hereditary hemochromatosis or hemosiderosis;
9. objection to receiving red blood cell transfusions;
10. current pregnancy (by self-report);
11. prisoners;
12. patient or parent decides against study participation.

IPD will not be shared.

Placebo tablets will be indistinguishable from iron tablets. Group allocation will not be accessible to participants, care providers, investigators, or outcomes assessors.