Ultrasonic Bone Scalpel (USBS) Does Not Reduce Blood Loss During Posterior Spinal Fusion (PSF) in Patients with Adolescent Idiopathic Scoliosis (AIS): Randomized Clinical Trial

Study design: Randomized Clinical Trial.

Objective: The aim of this study was to compare the efficacy of USBS with standard-of-care surgical instruments during posterior spinal fusion (PSF) in patients with adolescent idiopathic scoliosis (AIS) by evaluating the difference in estimated blood loss per level fused (EBL/level).

Summary of background data: PSF surgery for AIS is often associated with high blood loss. Use of an ultrasonic bone scalpel (USBS) has been proposed to reduce blood loss during scoliosis surgery.

Methods: This was a single-blinded (patient-blinded), randomized, controlled superiority trial. We randomized 66 patients with AIS undergoing PSF to the control group (osteotome) or the experimental group (USBS). The primary outcome was intraoperative EBL/level obtained from red blood cell salvage reports. One-year follow-up was available for 57 of 62 (92%) of patients.

Results: EBL/level averaged 35 and 39 mL/level in the experimental and control groups, respectively [adjusted mean difference USBS – osteotome -8 mL/level, 95% CI: -16.4 to 0.3 mL/level, P = 0.0575]. There was no difference in curve correction [adjusted mean difference: -1.7%, 95% CI: -7.0 to 3.6%, P = 0.5321] or operative time [adjusted mean difference: -3.55 minutes, 95% CI: -22.45 to 15.46 min, P = 0.7089] between groups. Complications requiring change in routine postoperative care were noted in eight patients: two occurred in patients assigned to the experimental group and six occurred in patients assigned to the control group.

Conclusion: There was no clinically significant difference in total blood loss, EBL/level, or complications between the two groups. In contrast to reports from other centers, at our high-volume spine center, USBS did not lead to reduced blood loss during PSF for AIS. These results may not be generalizable to centers with longer baseline operative times or higher baseline average blood loss during PSF for AIS.Level of Evidence: 1.