Alexander A. Theologis, Gregory M. Mundis Jr., Stacie Nguyen, David O. Okonkwo, Praveen V. Mummaneni, Justin S. Smith, Christopher I. Shaffrey, Richard Fessler, Shay Bess, Frank Schwab, Bassel G. Diebo, Douglas Burton, Robert Hart, Vedat Deviren and Christopher Ames
The aim of this study was to evaluate the utility of supplementing long thoracolumbar posterior instrumented fusion (posterior spinal fusion, PSF) with lateral interbody fusion (LIF) of the lumbar/thoracolumbar coronal curve apex in adult spinal deformity (ASD).
Two multicenter databases were evaluated. Adults who had undergone multilevel LIF of the coronal curve apex in addition to PSF with L5–S1 interbody fusion (LS+Apex group) were matched by number of posterior levels fused with patients who had undergone PSF with L5–S1 interbody fusion without LIF (LS-Only group). All patients had at least 2 years of follow-up. Percutaneous PSF and 3-column osteotomy (3CO) were excluded. Demographics, perioperative details, radiographic spinal deformity measurements, and HRQoL data were analyzed.
Thirty-two patients were matched (LS+Apex: 16; LS: 16) (6 men, 26 women; mean age 63 ± 10 years). Overall, the average values for measures of deformity were as follows: Cobb angle > 40°, sagittal vertical axis (SVA) > 6 cm, pelvic tilt (PT) > 25°, and mismatch between pelvic incidence (PI) and lumbar lordosis (LL) > 15°. There were no significant intergroup differences in preoperative radiographic parameters, although patients in the LS+Apex group had greater Cobb angles and less LL. Patients in the LS+Apex group had significantly more anterior levels fused (4.6 vs 1), longer operative times (859 vs 379 minutes), and longer length of stay (12 vs 7.5 days) (all p < 0.01). For patients in the LS+Apex group, Cobb angle, pelvic tilt (PT), lumbar lordosis (LL), PI-LL (lumbopelvic mismatch), Oswestry Disability Index (ODI) scores, and visual analog scale (VAS) scores for back and leg pain improved significantly (p < 0.05). For patients in the LS-Only group, there were significant improvements in Cobb angle, ODI score, and VAS scores for back and leg pain. The LS+Apex group had better correction of Cobb angles (56% vs 33%, p = 0.02), SVA (43% vs 5%, p = 0.46), LL (62% vs 13%, p = 0.35), and PI-LL (68% vs 33%, p = 0.32). Despite more LS+Apex patients having major complications (56% vs 13%; p = 0.02) and postoperative leg weakness (31% vs 6%, p = 0.07), there were no intergroup differences in 2-year outcomes.
Long open posterior instrumented fusion with or without multilevel LIF is used to treat a variety of coronal and sagittal adult thoracolumbar deformities. The addition of multilevel LIF to open PSF with L5–S1 interbody support in this small cohort was often used in more severe coronal and/or lumbopelvic sagittal deformities and offered better correction of major Cobb angles, lumbopelvic parameters, and SVA than posterior-only operations. As these advantages came at the expense of more major complications, more leg weakness, greater blood loss, and longer operative times and hospital stays without an improvement in 2-year outcomes, future investigations should aim to more clearly define deformities that warrant the addition of multilevel LIF to open PSF and L5–S1 interbody fusion.
Khoi D. Than, Paul Park, Kai-Ming Fu, Stacie Nguyen, Michael Y. Wang, Dean Chou, Pierce D. Nunley, Neel Anand, Richard G. Fessler, Christopher I. Shaffrey, Shay Bess, Behrooz A. Akbarnia, Vedat Deviren, Juan S. Uribe, Frank La Marca, Adam S. Kanter, David O. Okonkwo, Gregory M. Mundis Jr., Praveen V. Mummaneni and the International Spine Study Group
Minimally invasive surgery (MIS) techniques are increasingly used to treat adult spinal deformity. However, standard minimally invasive spinal deformity techniques have a more limited ability to restore sagittal balance and match the pelvic incidence–lumbar lordosis (PI-LL) than traditional open surgery. This study sought to compare “best” versus “worst” outcomes of MIS to identify variables that may predispose patients to postoperative success.
A retrospective review of minimally invasive spinal deformity surgery cases was performed to identify parameters in the 20% of patients who had the greatest improvement in Oswestry Disability Index (ODI) scores versus those in the 20% of patients who had the least improvement in ODI scores at 2 years' follow-up.
One hundred four patients met the inclusion criteria, and the top 20% of patients in terms of ODI improvement at 2 years (best group, 22 patients) were compared with the bottom 20% (worst group, 21 patients). There were no statistically significant differences in age, body mass index, pre- and postoperative Cobb angles, pelvic tilt, pelvic incidence, levels fused, operating room time, and blood loss between the best and worst groups. However, the mean preoperative ODI score was significantly higher (worse disability) at baseline in the group that had the greatest improvement in ODI score (58.2 vs 39.7, p < 0.001). There was no difference in preoperative PI-LL mismatch (12.8° best vs 19.5° worst, p = 0.298). The best group had significantly less postoperative sagittal vertical axis (SVA; 3.4 vs 6.9 cm, p = 0.043) and postoperative PI-LL mismatch (10.4° vs 19.4°, p = 0.027) than the worst group. The best group also had better postoperative visual analog scale back and leg pain scores (p = 0.001 and p = 0.046, respectively).
The authors recommend that spinal deformity surgeons using MIS techniques focus on correcting a patient's PI-LL mismatch to within 10° and restoring SVA to < 5 cm. Restoration of these parameters seems to impact which patients will attain the greatest degree of improvement in ODI outcomes, while the spines of patients who do the worst are not appropriately corrected and may be fused into a fixed sagittal plane deformity.
Juan S. Uribe, Armen R. Deukmedjian, Praveen V. Mummaneni, Kai-Ming G. Fu, Gregory M. Mundis Jr., David O. Okonkwo, Adam S. Kanter, Robert Eastlack, Michael Y. Wang, Neel Anand, Richard G. Fessler, Frank La Marca, Paul Park, Virginie Lafage, Vedat Deviren, Shay Bess and Christopher I. Shaffrey
It is hypothesized that minimally invasive surgical techniques lead to fewer complications than open surgery for adult spinal deformity (ASD). The goal of this study was to analyze matched patient cohorts in an attempt to isolate the impact of approach on adverse events.
Two multicenter databases queried for patients with ASD treated via surgery and at least 1 year of follow-up revealed 280 patients who had undergone minimally invasive surgery (MIS) or a hybrid procedure (HYB; n = 85) or open surgery (OPEN; n = 195). These patients were divided into 3 separate groups based on the approach performed and were propensity matched for age, preoperative sagittal vertebral axis (SVA), number of levels fused posteriorly, and lumbar coronal Cobb angle (CCA) in an attempt to neutralize these patient variables and to make conclusions based on approach only. Inclusion criteria for both databases were similar, and inclusion criteria specific to this study consisted of an age > 45 years, CCA > 20°, 3 or more levels of fusion, and minimum of 1 year of follow-up. Patients in the OPEN group with a thoracic CCA > 75° were excluded to further ensure a more homogeneous patient population.
In all, 60 matched patients were available for analysis (MIS = 20, HYB = 20, OPEN = 20). Blood loss was less in the MIS group than in the HYB and OPEN groups, but a significant difference was only found between the MIS and the OPEN group (669 vs 2322 ml, p = 0.001). The MIS and HYB groups had more fused interbody levels (4.5 and 4.1, respectively) than the OPEN group (1.6, p < 0.001). The OPEN group had less operative time than either the MIS or HYB group, but it was only statistically different from the HYB group (367 vs 665 minutes, p < 0.001). There was no significant difference in the duration of hospital stay among the groups. In patients with complete data, the overall complication rate was 45.5% (25 of 55). There was no significant difference in the total complication rate among the MIS, HYB, and OPEN groups (30%, 47%, and 63%, respectively; p = 0.147). No intraoperative complications were reported for the MIS group, 5.3% for the HYB group, and 25% for the OPEN group (p < 0.03). At least one postoperative complication occurred in 30%, 47%, and 50% (p = 0.40) of the MIS, HYB, and OPEN groups, respectively. One major complication occurred in 30%, 47%, and 63% (p = 0.147) of the MIS, HYB, and OPEN groups, respectively. All patients had significant improvement in both the Oswestry Disability Index (ODI) and visual analog scale scores after surgery (p < 0.001), although the MIS group did not have significant improvement in leg pain. The occurrence of complications had no impact on the ODI.
Results in this study suggest that the surgical approach may impact complications. The MIS group had significantly fewer intraoperative complications than did either the HYB or OPEN groups. If the goals of ASD surgery can be achieved, consideration should be given to less invasive techniques.
Christopher P. Ames, Justin S. Smith, Justin K. Scheer, Christopher I. Shaffrey, Virginie Lafage, Vedat Deviren, Bertrand Moal, Themistocles Protopsaltis, Praveen V. Mummaneni, Gregory M. Mundis Jr., Richard Hostin, Eric Klineberg, Douglas C. Burton, Robert Hart, Shay Bess, Frank J. Schwab and the International Spine Study Group
Cervical spine osteotomies are powerful techniques to correct rigid cervical spine deformity. Many variations exist, however, and there is no current standardized system with which to describe and classify cervical osteotomies. This complicates the ability to compare outcomes across procedures and studies. The authors' objective was to establish a universal nomenclature for cervical spine osteotomies to provide a common language among spine surgeons.
A proposed nomenclature with 7 anatomical grades of increasing extent of bone/soft tissue resection and destabilization was designed. The highest grade of resection is termed the major osteotomy, and an approach modifier is used to denote the surgical approach(es), including anterior (A), posterior (P), anterior-posterior (AP), posterior-anterior (PA), anterior-posterior-anterior (APA), and posterior-anterior-posterior (PAP). For cases in which multiple grades of osteotomies were performed, the highest grade is termed the major osteotomy, and lower-grade osteotomies are termed minor osteotomies. The nomenclature was evaluated by 11 reviewers through 25 different radiographic clinical cases. The review was performed twice, separated by a minimum 1-week interval. Reliability was assessed using Fleiss kappa coefficients.
The average intrarater reliability was classified as “almost perfect agreement” for the major osteotomy (0.89 [range 0.60–1.00]) and approach modifier (0.99 [0.95–1.00]); it was classified as “moderate agreement” for the minor osteotomy (0.73 [range 0.41–1.00]). The average interrater reliability for the 2 readings was the following: major osteotomy, 0.87 (“almost perfect agreement”); approach modifier, 0.99 (“almost perfect agreement”); and minor osteotomy, 0.55 (“moderate agreement”). Analysis of only major osteotomy plus approach modifier yielded a classification that was “almost perfect” with an average intrarater reliability of 0.90 (0.63–1.00) and an interrater reliability of 0.88 and 0.86 for the two reviews.
The proposed cervical spine osteotomy nomenclature provides the surgeon with a simple, standard description of the various cervical osteotomies. The reliability analysis demonstrated that this system is consistent and directly applicable. Future work will evaluate the relationship between this system and health-related quality of life metrics.