Abstracts of the 2013 Annual Meeting of the AANS/CNS Section on Disorders of the Spine and Peripheral Nerves
Phoenix, Arizona • March 6–9, 2013
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.
Alexander A. Theologis, Tamir Ailon, Justin K. Scheer, Justin S. Smith, Christopher I. Shaffrey, Shay Bess, Munish Gupta, Eric O. Klineberg, Khaled Kebaish, Frank Schwab, Virginie Lafage, Douglas Burton, Robert Hart, Christopher P. Ames and The International Spine Study Group
The objective of this study was to isolate whether the effect of a baseline clinical history of depression on outcome is independent of associated physical disability and to evaluate which mental health screening tool has the most utility in determining 2-year clinical outcomes after adult spinal deformity (ASD) surgery.
Consecutively enrolled patients with ASD in a prospective, multicenter ASD database who underwent surgical intervention with a minimum 2-year follow-up were retrospectively reviewed. A subset of patients who completed the Distress and Risk Assessment Method (DRAM) was also analyzed. The effects of categorical baseline depression and DRAM classification on the Oswestry Disability Index (ODI), SF-36, and Scoliosis Research Society questionnaire (SRS-22r) were assessed using univariate and multivariate linear regression analyses. The probability of achieving ≥ 1 minimal clinically important difference (MCID) on the ODI based on the DRAM’s Modified Somatic Perceptions Questionnaire (MSPQ) score was estimated.
Of 267 patients, 66 (24.7%) had self-reported preoperative depression. Patients with baseline depression had significantly more preoperative back pain, greater BMI and Charlson Comorbidity Indices, higher ODIs, and lower SRS-22r and SF-36 Physical/Mental Component Summary (PCS/MCS) scores compared with those without self-reported baseline depression. They also had more severe regional and global sagittal malalignment. After adjusting for these differences, preoperative depression did not impact 2-year ODI, PCS/MCS, or SRS-22r totals (p > 0.05). Compared with those in the “normal” DRAM category, “distressed somatics” (n = 11) had higher ODI (+23.5 points), lower PCS (−10.9), SRS-22r activity (−0.9), and SRS-22r total (−0.8) scores (p ≤ 0.01), while “distressed depressives” (n = 25) had lower PCS (−8.4) and SRS-22r total (−0.5) scores (p < 0.05). After adjusting for important covariates, each additional point on the baseline MSPQ was associated with a 0.8-point increase in 2-year ODI (p = 0.03). The probability of improving by at least 1 MCID in 2-year ODI ranged from 77% to 21% for MSPQ scores 0–20, respectively.
A baseline clinical history of depression does not correlate with worse 2-year outcomes after ASD surgery after adjusting for baseline differences in comorbidities, health-related quality of life, and spinal deformity severity. Conversely, DRAM improved risk stratification of patient subgroups predisposed to achieving suboptimal surgical outcomes. The DRAM’s MSPQ was more predictive than MCS and SRS mental domain for 2-year outcomes and may be a valuable tool for surgical screening.