Christopher P. Ames, Justin S. Smith, Robert Eastlack, Donald J. Blaskiewicz, Christopher I. Shaffrey, Frank Schwab, Shay Bess, Han Jo Kim, Gregory M. Mundis Jr., Eric Klineberg, Munish Gupta, Michael O’Brien, Richard Hostin, Justin K. Scheer, Themistocles S. Protopsaltis, Kai-Ming G. Fu, Robert Hart, Todd J. Albert, K. Daniel Riew, Michael G. Fehlings, Vedat Deviren, Virginie Lafage and International Spine Study Group
Despite the complexity of cervical spine deformity (CSD) and its significant impact on patient quality of life, there exists no comprehensive classification system. The objective of this study was to develop a novel classification system based on a modified Delphi approach and to characterize the intra- and interobserver reliability of this classification.
Based on an extensive literature review and a modified Delphi approach with an expert panel, a CSD classification system was generated. The classification system included a deformity descriptor and 5 modifiers that incorporated sagittal, regional, and global spinopelvic alignment and neurological status. The descriptors included: “C,” “CT,” and “T” for primary cervical kyphotic deformities with an apex in the cervical spine, cervicothoracic junction, or thoracic spine, respectively; “S” for primary coronal deformity with a coronal Cobb angle ≥ 15°; and “CVJ” for primary craniovertebral junction deformity. The modifiers included C2–7 sagittal vertical axis (SVA), horizontal gaze (chin-brow to vertical angle [CBVA]), T1 slope (TS) minus C2–7 lordosis (TS–CL), myelopathy (modified Japanese Orthopaedic Association [mJOA] scale score), and the Scoliosis Research Society (SRS)-Schwab classification for thoracolumbar deformity. Application of the classification system requires the following: 1) full-length standing posteroanterior (PA) and lateral spine radiographs that include the cervical spine and femoral heads; 2) standing PA and lateral cervical spine radiographs; 3) completed and scored mJOA questionnaire; and 4) a clinical photograph or radiograph that includes the skull for measurement of the CBVA. A series of 10 CSD cases, broadly representative of the classification system, were selected and sufficient radiographic and clinical history to enable classification were assembled. A panel of spinal deformity surgeons was queried to classify each case twice, with a minimum of 1 intervening week. Inter- and intrarater reliability measures were based on calculations of Fleiss k coefficient values.
Twenty spinal deformity surgeons participated in this study. Interrater reliability (Fleiss k coefficients) for the deformity descriptor rounds 1 and 2 were 0.489 and 0.280, respectively, and mean intrarater reliability was 0.584. For the modifiers, including the SRS-Schwab components, the interrater (round 1/round 2) and intrarater reliabilities (Fleiss k coefficients) were: C2–7 SVA (0.338/0.412, 0.584), horizontal gaze (0.779/0.430, 0.768), TS-CL (0.721/0.567, 0.720), myelopathy (0.602/0.477, 0.746), SRS-Schwab curve type (0.590/0.433, 0.564), pelvic incidence-lumbar lordosis (0.554/0.386, 0.826), pelvic tilt (0.714/0.627, 0.633), and C7-S1 SVA (0.071/0.064, 0.233), respectively. The parameter with the poorest reliability was the C7–S1 SVA, which may have resulted from differences in interpretation of positive and negative measurements.
The proposed classification provides a mechanism to assess CSD within the framework of global spinopelvic malalignment and clinically relevant parameters. The intra- and interobserver reliabilities suggest moderate agreement and serve as the basis for subsequent improvement and study of the proposed classification.
Taemin Oh, Justin K. Scheer, Robert Eastlack, Justin S. Smith, Virginie Lafage, Themistocles S. Protopsaltis, Eric Klineberg, Peter G. Passias, Vedat Deviren, Richard Hostin, Munish Gupta, Shay Bess, Frank Schwab, Christopher I. Shaffrey and Christopher P. Ames
Alignment changes in the cervical spine that occur following surgical correction for thoracic deformity remain poorly understood. The purpose of this study was to evaluate such changes in a cohort of adults with thoracic deformity treated surgically.
The authors conducted a multicenter retrospective analysis of consecutive patients with thoracic deformity. Inclusion criteria for this study were as follows: corrective osteotomy for thoracic deformity, upper-most instrumented vertebra (UIV) between T-1 and T-4, lower-most instrumented vertebra (LIV) at or above L-5 (LIV ≥ L-5) or at the ilium (LIV-ilium), and a minimum radiographic follow-up of 2 years. Sagittal radiographic parameters were assessed preoperatively as well as at 3 months and 2 years postoperatively, including the C-7 sagittal vertical axis (SVA), C2–7 cervical lordosis (CL), C2–7 SVA, T-1 slope (T1S), T1S minus CL (T1S-CL), T2–12 thoracic kyphosis (TK), apical TK, lumbar lordosis (LL), pelvic incidence (PI), PI-LL, pelvic tilt (PT), and sacral slope (SS).
Fifty-seven patients with a mean age of 49.1 ± 14.6 years met the study inclusion criteria. The preoperative prevalence of increased CL (CL > 15°) was 48.9%. Both 3-month and 2-year apical TK improved from baseline (p < 0.05, statistically significant). At the 2-year follow-up, only the C2–7 SVA increased significantly from baseline (p = 0.01), whereas LL decreased from baseline (p < 0.01). The prevalence of increased CL was 35.3% at 3 months and 47.8% at 2 years, which did not represent a significant change. Postoperative cervical alignment changes were not significantly different from preoperative values regardless of the LIV (LIV ≥ L-5 or LIV-ilium, p > 0.05 for both). In a subset of patients with a maximum TK ≥ 60° (35 patients) and 3-column osteotomy (38 patients), no significant postoperative cervical changes were seen.
Increased CL is common in adult spinal deformity patients with thoracic deformities and, unlike after lumbar corrective surgery, does not appear to normalize after thoracic corrective surgery. Cervical sagittal malalignment (C2–7 SVA) also increases postoperatively. Surgeons should be aware that spontaneous cervical alignment normalization might not occur following thoracic deformity correction.
Justin K. Scheer, Justin S. Smith, Aaron J. Clark, Virginie Lafage, Han Jo Kim, John D. Rolston, Robert Eastlack, Robert A. Hart, Themistocles S. Protopsaltis, Michael P. Kelly, Khaled Kebaish, Munish Gupta, Eric Klineberg, Richard Hostin, Christopher I. Shaffrey, Frank Schwab, Christopher P. Ames and the International Spine Study Group
Back and leg pain are the primary outcomes of adult spinal deformity (ASD) and predict patients' seeking of surgical management. The authors sought to characterize changes in back and leg pain after operative or nonoperative management of ASD. Outcomes were assessed according to pain severity, type of surgical procedure, Scoliosis Research Society (SRS)–Schwab spine deformity class, and patient satisfaction.
This study retrospectively reviewed data in a prospective multicenter database of ASD patients. Inclusion criteria were the following: age > 18 years and presence of spinal deformity as defined by a scoliosis Cobb angle ≥ 20°, sagittal vertical axis length ≥ 5 cm, pelvic tilt angle ≥ 25°, or thoracic kyphosis angle ≥ 60°. Patients were grouped into nonoperated and operated subcohorts and by the type of surgical procedure, spine SRS-Schwab deformity class, preoperative pain severity, and patient satisfaction. Numerical rating scale (NRS) scores of back and leg pain, Oswestry Disability Index (ODI) scores, physical component summary (PCS) scores of the 36-Item Short Form Health Survey, minimum clinically important differences (MCIDs), and substantial clinical benefits (SCBs) were assessed.
Patients in whom ASD had been operatively managed were 6 times more likely to have an improvement in back pain and 3 times more likely to have an improvement in leg pain than patients in whom ASD had been nonoperatively managed. Patients whose ASD had been managed nonoperatively were more likely to have their back or leg pain remain the same or worsen. The incidence of postoperative leg pain was 37.0% at 6 weeks postoperatively and 33.3% at the 2-year follow-up (FU). At the 2-year FU, among patients with any preoperative back or leg pain, 24.3% and 37.8% were free of back and leg pain, respectively, and among patients with severe (NRS scores of 7–10) preoperative back or leg pain, 21.0% and 32.8% were free of back and leg pain, respectively. Decompression resulted in more patients having an improvement in leg pain and their pain scores reaching MCID. Although osteotomies improved back pain, they were associated with a higher incidence of leg pain. Patients whose spine had an SRS-Schwab coronal curve Type N deformity (sagittal malalignment only) were least likely to report improvements in back pain. Patients with a Type L deformity were most likely to report improved back or leg pain and to have reductions in pain severity scores reaching MCID and SCB. Patients with a Type D deformity were least likely to report improved leg pain and were more likely to experience a worsening of leg pain. Preoperative pain severity affected pain improvement over 2 years because patients who had higher preoperative pain severity experienced larger improvements, and their changes in pain severity were more likely to reach MCID/SCB than for those reporting lower preoperative pain. Reductions in back pain contributed to improvements in ODI and PCS scores and to patient satisfaction more than reductions in leg pain did.
The authors' results provide a valuable reference for counseling patients preoperatively about what improvements or worsening in back or leg pain they may experience after surgical intervention for ASD.
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.