Sagittal Deformity Correction With a Schwab 4 Osteotomy and a Large-Footprint Interbody Cage: Radiographic and Patient-Reported Outcomes: Case Series

BACKGROUND AND OBJECTIVES: Sagittal plane deformities can profoundly affect health-related quality-of-life and patient-reported outcomes. We aimed to present our experience with Schwab 4 osteotomy and explore associated radiographic and patient-reported outcomes. METHODS: We conducted a single-center retrospective review of consecutive patients who underwent surgery for severe adult spinal deformities. Patients were included if they underwent a Schwab 4 osteotomy with a large-footprint cage used at the osteotomy site. We recorded patient demographics, surgical variables, preoperative and postoperative radiographic parameters, and patient-reported outcomes. RESULTS: Data from 27 patients with severe spinal deformities who underwent a Schwab 4 osteotomy and had a follow-up of at least 2 years postoperatively were included. The mean age was 65.0 ± 7.7 years, the body mass index was 31.1 ± 5.5, and the mean Charlson comorbidity index was 3.4 ± 1.6; all patients had previous lumbar surgeries. The mean estimated blood loss was 1665 ± 620 mL. The mean operative duration was 8.86 ± 1.17 hours. The mean number of fused levels was 10.3 ± 3.3. Complications occurred in 11 patients (40.7%), with durotomies (33.3%) and transient radiculopathy (22.2%) being most common, followed by wound infection (14.8%) and proximal junctional kyphosis or failure (11.1%). Radiographic parameters that demonstrated significant improvement after surgery included a lumbar lordosis change of -32.1° ± 12°, a segmental lordosis correction at the osteotomy site of -30.8° ± 10°, a pelvic incidence-lumbar lordosis mismatch improvement of -32° ± 14.7°, a sagittal vertical axis correction of -107.1 ± 86.7 mm, and a T4 pelvic angle-L1 pelvic angle mismatch improvement of -7.4° ± 13° (all P < .001). Patient-reported outcomes also improved significantly, with the Oswestry Disability Index decreasing from 34.9 ± 8.3 to 22.2 ± 9.2 and the Scoliosis Research Society-22 revised questionnaire responses showing significant improvements in total scores (all P < .001). CONCLUSION: Schwab 4 osteotomy with a large-footprint interbody cage, despite its associated complications, demonstrated significant improvements in patient-reported outcomes and radiographic parameters. This technique can provide meaningful correction and functional benefit for patients with severe sagittal plane deformity.