Paul Park, Kai-Ming Fu, Robert K. Eastlack, Stacie Tran, Gregory M. Mundis Jr., Juan S. Uribe, Michael Y. Wang, Khoi D. Than, David O. Okonkwo, Adam S. Kanter, Pierce D. Nunley, Neel Anand, Richard G. Fessler, Dean Chou, Mark E. Oppenlander, Praveen V. Mummaneni and the International Spine Study Group
It is now well accepted that spinopelvic parameters are correlated with clinical outcomes in adult spinal deformity (ASD). The purpose of this study was to determine whether obtaining optimal spinopelvic alignment was absolutely necessary to achieve a minimum clinically important difference (MCID) or substantial clinical benefit (SCB).
A multicenter retrospective review of patients who underwent less-invasive surgery for ASD was conducted. Inclusion criteria were age ≥ 18 years and one of the following: coronal Cobb angle > 20°, sagittal vertical axis (SVA) > 5 cm, pelvic tilt (PT) > 20°, or pelvic incidence to lumbar lordosis (PI-LL) mismatch > 10°. A total of 223 patients who were treated with circumferential minimally invasive surgery or hybrid surgery and had a minimum 2-year follow-up were identified. Based on optimal spinopelvic parameters (PI-LL mismatch ± 10° and SVA < 5 cm), patients were divided into aligned (AL) or malaligned (MAL) groups. The primary clinical outcome studied was the Oswestry Disability Index (ODI) score.
There were 74 patients in the AL group and 149 patients in the MAL group. Age and body mass index were similar between groups. Although the baseline SVA was similar, PI-LL mismatch (9.9° vs 17.7°, p = 0.002) and PT (19° vs 24.7°, p = 0.001) significantly differed between AL and MAL groups, respectively. As expected postoperatively, the AL and MAL groups differed significantly in PI-LL mismatch (−0.9° vs 13.1°, p < 0.001), PT (14° vs 25.5°, p = 0.001), and SVA (11.8 mm vs 48.3 mm, p < 0.001), respectively. Notably, there was no difference in the proportion of AL or MAL patients in whom an MCID (52.75% vs 61.1%, p > 0.05) or SCB (40.5% vs 46.3%, p > 0.05) was achieved for ODI score, respectively. Similarly, no differences in percentage of patients obtaining an MCID or SCB for visual analog scale back and leg pain score were observed. On multivariate analysis controlling for surgical and preoperative demographic differences, achieving optimal spinopelvic parameters was not associated with achieving an MCID (OR 0.645, 95% CI 0.31–1.33) or an SCB (OR 0.644, 95% CI 0.31–1.35) for ODI score.
Achieving optimal spinopelvic parameters was not a predictor for achieving an MCID or SCB. Since spinopelvic parameters are correlated with clinical outcomes, the authors’ findings suggest that the presently accepted optimal spinopelvic parameters may require modification. Other factors, such as improvement in neurological symptoms and/or segmental instability, also likely impacted the clinical outcomes.
Khoi D. Than, Praveen V. Mummaneni, Kelly J. Bridges, Stacie Tran, Paul Park, Dean Chou, Frank La Marca, Juan S. Uribe, Todd D. Vogel, Pierce D. Nunley, Robert K. Eastlack, Neel Anand, David O. Okonkwo, Adam S. Kanter and Gregory M. Mundis Jr.
High-quality studies that compare outcomes of open and minimally invasively placed pedicle screws for adult spinal deformity are needed. Therefore, the authors compared differences in complications from a circumferential minimally invasive spine (MIS) surgery and those from a hybrid surgery.
A retrospective review of a multicenter database of patients with spinal deformity who were treated with an MIS surgery was performed. Database inclusion criteria included an age of ≥ 18 years and at least 1 of the following: a coronal Cobb angle of > 20°, a sagittal vertical axis of > 5 cm, a pelvic incidence–lumbar lordosis angle of > 10°, and/or a pelvic tilt of > 20°. Patients were propensity matched according to the levels instrumented.
In this database, a complete data set was available for 165 patients, and after those who underwent 3-column osteotomy were excluded, 137 patients were available for analysis; 76 patients remained after propensity matching (MIS surgery group 38 patients, hybrid surgery group 38 patients). The authors found no difference in demographics, number of levels instrumented, or preoperative and postoperative radiographic results. At least 1 complication was suffered by 55.3% of patients in the hybrid surgery group and 44.7% of those in the MIS surgery group (p = 0.359). Patients in the MIS surgery group had significantly fewer neurological, operative, and minor complications than those in the hybrid surgery group. The reoperation rates in both groups were similar. The most common complication category for the MIS surgery group was radiographic and for the hybrid surgery group was neurological. Patients in both groups experienced postoperative improvement in their Oswestry Disability Index and visual analog scale (VAS) back and leg pain scores (all p < 0.05); however, MIS surgery provided a greater reduction in leg pain according to VAS scores.
Overall complication rates in the MIS and hybrid surgery groups were similar. MIS surgery resulted in significantly fewer neurological, operative, and minor complications. Reoperation rates in the 2 groups were similar, and despite complications, the patients reported significant improvement in their pain and function.
Pooria Hosseini, Gregory M. Mundis Jr., Robert K. Eastlack, Ramin Bagheri, Enrique Vargas, Stacie Tran and Behrooz A. Akbarnia
Sagittal malalignment decreases patients’ quality of life and may require surgical correction to achieve realignment goals. High-risk posterior-based osteotomy techniques are the current standard treatment for addressing sagittal malalignment. More recently, anterior lumbar interbody fusion, anterior column realignment (ALIF ACR) has been introduced as an alternative for correction of sagittal deformity. The objective of this paper was to report clinical and radiographic results for patients treated using the ALIF-ACR technique.
A retrospective study of 39 patients treated with ALIF ACR was performed. Patient demographics, operative details, radiographic parameters, neurological assessments, outcome measures, and preoperative, postoperative, and mean 1-year follow-up complications were studied.
The patient population comprised 39 patients (27 females and 12 males) with a mean follow-up of 13.3 ± 4.7 months, mean age of 66.1 ± 11.6 years, and mean body mass index of 27.3 ± 6.2 kg/m2. The mean number of ALIF levels treated was 1.5 ± 0.5. Thirty-three (84.6%) of 39 patients underwent posterior spinal fixation and 33 (84.6%) of 39 underwent posterior column osteotomy, of which 20 (60.6%) of 33 procedures were performed at the level of the ALIF ACR. Pelvic tilt, sacral slope, and pelvic incidence were not statistically significantly different between the preoperative and postoperative periods and between the preoperative and 1-year follow-up periods (except for PT between the preoperative and 1-year follow-up, p = 0.018). Sagittal vertical axis, T-1 spinopelvic inclination, lumbar lordosis, pelvic incidence–lumbar lordosis mismatch, intradiscal angle, and motion segment angle all improved from the preoperative to postoperative period and the preoperative to 1-year follow-up (p < 0.05). The changes in motion segment angle and intradiscal angle achieved in the ALIF-ACR group without osteotomy compared with the ALIF-ACR group with osteotomy at the level of ACR were not statistically significant. Total visual analog score, Oswestry Disability Index, and Scoliosis Research Society–22 scores all improved from preoperative to postoperative and preoperative to 1-year follow-up. Fourteen patients (35.9%) experienced 26 complications (15 major and 11 minor). Eleven patients required reoperation. The most common complication was proximal junctional kyphosis (6/26 complications, 23%) followed by vertebral body/endplate fracture (3/26, 12%).
This study showed satisfactory radiographic and clinical outcomes at the 1-year follow-up. Proximal junctional kyphosis was the most common complication followed by fracture, complications that are commonly associated with sagittal realignment surgery and may not be mitigated by the anterior approach.