Less invasive surgery for treating adult spinal deformities: ceiling effects for deformity correction with 3 different techniques

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Minimally invasive surgery (MIS) options for the treatment of adult spinal deformity (ASD) have advanced significantly over the past decade. However, a wide array of options have been described as being MIS or less invasive. In this study the authors investigated a multiinstitutional cohort of patients with ASD who were treated with less invasive methods to determine the extent of deformity correction achieved.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>This study was a retrospective review of multicenter prospectively collected data in 85 consecutive patients with ASD undergoing MIS surgery. Inclusion criteria were as follows: age older than 45 years; minimum 20° coronal lumbar Cobb angle; and 1 year of follow-up. Procedures were classified as follows: 1) stand-alone (n = 7); 2) circumferential MIS (n = 43); or 3) hybrid (n = 35).</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>An average of 4.2 discs (range 3–7) were fused, with a mean follow-up duration of 26.1 months in this study. For the stand-alone group the preoperative Cobb range was 22°–51°, with 57% greater than 30° and 28.6% greater than 50°. The mean Cobb angle improved from 35.7° to 30°. A ceiling effect of 23° for curve correction was observed, regardless of preoperative curve severity. For the circumferential MIS group the preoperative Cobb range was 19°–62°, with 44% greater than 30° and 5% greater than 50°. The mean Cobb angle improved from 32° to 12°. A ceiling effect of 34° for curve correction was observed. For the hybrid group the preoperative Cobb range was 23°–82°, with 74% greater than 30° and 23% greater than 50°. The mean Cobb angle improved from 43° to 15°. A ceiling effect of 55° for curve correction was observed.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Specific procedures for treating ASD have particular limitations for scoliotic curve correction. Less invasive techniques were associated with a reduced ability to straighten the spine, particularly with advanced curves. These data can guide preoperative technique selection when treating patients with ASD.</jats:p></jats:sec>

Correction of marked sagittal deformity with circumferential minimally invasive surgery using oblique lateral interbody fusion in adult spinal deformity

“…In our study, the maximum dSVA was 141.5 mm, which was greater than that previously reported. Other studies reported the maximum dLL and corrected LL by cMIS were 23°and 54°, respectively [25,26]. In our study, the maximum dLL and corrected LL were 67.5°a nd 62.4°, respectively, which were also greater than those of previous reports.…”

“…The recent concept of cMIS is a combination of MIS lumbar interbody fusion and percutaneous fixation without osteotomy [3,[5][6][7][8]. Previously, cMIS was not indicated for sagittal correction of ASD [7,14,25,26]. Recent studies reported that cMIS could be indicated only for mild deformity, but osteotomies were required for marked deformity [4,5].…”

“…A ceiling effect is referred to as the maximum correction of sagittal parameters allowed by deformity surgery [16,26]. Anand et al reported that the ceiling effect of dSVA was 120 mm for cMIS [16].…”

Cost minimization in treatment of adult degenerative scoliosis

“…These findings are consistent with the observations of the International Spine Study Group (ISSG) that less invasive surgery for treating ASD have limitations for scoliotic-curve correction for advanced curves. 26 Overall, a minority of patients in each cohort experienced complications. Patients in the Open cohort experienced more dural tears and postoperative infections, while patients in the MIS cohort experienced greater postoperative radiating pain and need for revision surgery.…”

Role of minimally invasive surgery for adult spinal deformity in preventing complications

“…Early results are promising, however, ASD patients with severe fixed sagittal imbalance and spinopelvic malalignment are not ideal candidates for MIS surgery alone [39,40]. The MIS approach remains in its early stage and work remains to produce more robust data with longer follow-up to make definitive claims regarding its efficacy and safety.…”