Browsing by Author "Ramchandran, Subaraman"

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    ItemOpen Access
    Analysis of Successful Versus Failed Radiographic Outcomes After Cervical Deformity Surgery.
    (Spine, 2018-07) Protopsaltis, Themistocles S; Ramchandran, Subaraman; Hamilton, D Kojo; Sciubba, Daniel; Passias, Peter G; Lafage, Virginie; Lafage, Renaud; Smith, Justin S; Hart, Robert A; Gupta, Munish; Burton, Douglas; Bess, Shay; Shaffrey, Christopher; Ames, Christopher P; International Spine Study Group (ISSG)

    Study design

    Prospective multicenter cohort study with consecutive enrollment.

    Objective

    To evaluate preoperative alignment and surgical factors associated with suboptimal early postoperative radiographic outcomes after surgery for cervical deformity.

    Summary of background data

    Recent studies have demonstrated correlation between cervical sagittal alignment and patient-reported outcomes. Few studies have explored cervical deformity correction prospectively, and the factors that result in successful versus failed cervical alignment corrections remain unclear.

    Methods

    Patients with adult cervical deformity (ACD) included with either cervical kyphosis more than 10°, C2-C7 sagittal vertical axis (cSVA) of more than 4 cm, or chin-brow vertical angle of more than 25°. Patients were categorized into failed outcomes group if cSVA of more than 4 cm or T1 slope and cervical lordosis (TS-CL) of more than 20° at 6 months postoperatively.

    Results

    A total of 71 patients with ACD (mean age 62 yr, 56% women, 41% revisions) were included. Fourty-five had primary cervical deformities and 26 at the cervico-thoracic junction. Thirty-three (46.4%) had failed radiographic outcomes by cSVA and 46 (64.7%) by TS-CL. Failure to restore cSVA was associated with worse preoperative C2 pelvic tilt angle (CPT: 64.4° vs. 47.8°, P = 0.01), worse postoperative C2 slope (35.0° vs. 23.8°, P = 0.004), TS-CL (35.2° vs. 24.9°, P = 0.01), CPT (47.9° vs. 28.2°, P < 0.001), "+" Schwab modifiers (P = 0.007), revision surgery (P = 0.05), and failure to address the secondary, thoracolumbar driver of the deformity (P = 0.02). Failure to correct TS-CL was associated with worse preoperative cervical kyphosis (10.4° vs. -2.1°, P = 0.03), CPT (52.6° vs. 39.1°, P = 0.04), worse postoperative C2 slope (30.2° vs. 13.3°, P < 0.001), cervical lordosis (-3.6° vs. -15.1°, P = 0.01), and CPT (37.7° vs. 24.0°, P < 0.001). Multivariate analysis revealed postoperative distal junctional kyphosis associated with suboptimal outcomes by cSVA (odds ratio 0.06, confidence interval 0.01-0.4, P = 0.004) and TS-CL (odds ratio 0.15, confidence interval 0.02-0.97, P = 0.05).

    Conclusion

    Factors associated with failure to correct the cSVA included revision surgery, worse preoperative CPT, and concurrent thoracolumbar deformity. Failure to correct the TS-CL mismatch was associated with worse preoperative cervical kyphosis and CPT. Occurrence of early postoperative distal junctional kyphosis significantly affects postoperative radiographic outcomes.

    Level of evidence

    3.
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    ItemOpen Access
    Assessment of Impact of Long-Cassette Standing X-Rays on Surgical Planning for Cervical Pathology: An International Survey of Spine Surgeons.
    (Neurosurgery, 2016-05) Ramchandran, Subaraman; Smith, Justin S; Ailon, Tamir; Klineberg, Eric; Shaffrey, Christopher; Lafage, Virginie; Schwab, Frank; Bess, Shay; Daniels, Alan; Scheer, Justin K; Protopsaltis, Themi S; Arnold, Paul; Haid, Regis W; Chapman, Jens; Fehlings, Michael G; Ames, Christopher P; AOSpine North America, International Spine Study Group

    Background

    Understanding the role of regional segments of the spine in maintaining global balance has garnered significant attention recently. Long-cassette radiographs (LCR) are necessary to evaluate global spinopelvic alignment. However, it is unclear how LCRs impact operative decision-making for cervical spine pathology.

    Objective

    To evaluate whether the addition of LCRs results in changes to respondents' operative plans compared to standard imaging of the involved cervical spine in an international survey of spine surgeons.

    Methods

    Fifteen cases (5 control cases with normal and 10 test cases with abnormal global alignment) of cervical pathology were presented online with a vignette and cervical imaging. Surgeons were asked to select a surgical plan from 6 options, ranging from the least (1 point) to most (6 points) extensive. Cases were then reordered and presented again with LCRs and the same surgical plan question.

    Results

    One hundred fifty-seven surgeons completed the survey, of which 79% were spine fellowship trained. The mean response scores for surgical plan increased from 3.28 to 4.0 (P = .003) for test cases with the addition of LCRs. However, no significant changes (P = .10) were identified for the control cases. In 4 of the test cases with significant mid thoracic kyphosis, 29% of participants opted for the more extensive surgical options of extension to the mid and lower thoracic spine when they were provided with cervical imaging only, which significantly increased to 58.3% upon addition of LCRs.

    Conclusion

    In planning for cervical spine surgery, surgeons should maintain a low threshold for obtaining LCRs to assess global spinopelvic alignment.
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    ItemOpen Access
    Characterizing Adult Cervical Deformity and Disability Based on Existing Cervical and Adult Deformity Classification Schemes at Presentation and Following Correction.
    (Neurosurgery, 2018-02) Passias, Peter G; Jalai, Cyrus M; Smith, Justin S; Lafage, Virginie; Diebo, Bassel G; Protopsaltis, Themistocles; Poorman, Gregory; Ramchandran, Subaraman; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; Schwab, Frank

    Background

    Adult cervical deformity (ACD) classifications have not been implemented in a prospective ACD population and in conjunction with adult spinal deformity (ASD) classifications.

    Objective

    To characterize cervical deformity type and malalignment with 2 classifications (Ames-ACD and Schwab-ASD).

    Methods

    Retrospective review of a prospective multicenter ACD database. Inclusion: patients ≥18 yr with pre- and postoperative radiographs. Patients were classified with Ames-ACD and Schwab-ASD schemes. Ames-ACD descriptors (C = cervical, CT = cervicothoracic, T = thoracic, S = coronal, CVJ = craniovertebral) and alignment modifiers (cervical sagittal vertical axis [cSVA], T1 slope minus cervical lordosis [TS-CL], modified Japanese Ortphopaedic Association [mJOA] score, horizontal gaze) were assigned. Schwab-ASD curve type stratification and modifier grades were also designated. Deformity and alignment group distributions were compared with Pearson χ2/ANOVA.

    Results

    Ames-ACD descriptors in 84 patients: C = 49 (58.3%), CT = 20 (23.8%), T = 9 (10.7%), S = 6 (7.1%). cSVA modifier grades differed in C, CT, and T deformities (P < .019). In C, TS-CL grade prevalence differed (P = .031). Among Ames-ACD modifiers, high (1+2) cSVA grades differed across deformities (C = 47.7%, CT = 89.5%, T = 77.8%, S = 50.0%, P = .013). Schwab-ASD curve type and presence (n = 74, T = 2, L = 6, D = 2) differed significantly in S deformities (P < .001). Higher Schwab-ASD pelvic incidence minus lumbar lordosis grades were less likely in Ames-ACD CT deformities (P = .027). Higher pelvic tilt grades were greater in high (1+2) cSVA (71.4% vs 36.0%, P = .015) and high (2+3) mJOA (24.0% vs 38.1%, P = .021) scores. Postoperatively, C and CT deformities had a trend toward lower cSVA grades, but only C deformities differed in TS-CL grade prevalence (0 = 31.3%, 1 = 12.2%, 2 = 56.1%, P = .007).

    Conclusion

    Cervical deformities displayed higher TS-CL grades and different cSVA grade distributions. Preoperative associations with global alignment modifiers and Ames-ACD descriptors were observed, though only cervical modifiers showed postoperative differences.
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    ItemOpen Access
    Comparative analysis of perioperative complications between a multicenter prospective cervical deformity database and the Nationwide Inpatient Sample database.
    (The spine journal : official journal of the North American Spine Society, 2017-11) Passias, Peter G; Horn, Samantha R; Jalai, Cyrus M; Poorman, Gregory; Bono, Olivia J; Ramchandran, Subaraman; Smith, Justin S; Scheer, Justin K; Sciubba, Daniel M; Hamilton, D Kojo; Mundis, Gregory; Oh, Cheongeun; Klineberg, Eric O; Lafage, Virginie; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study Group

    Background context

    Complication rates for adult cervical deformity are poorly characterized given the complexity and heterogeneity of cases.

    Purpose

    To compare perioperative complication rates following adult cervical deformity corrective surgery between a prospective multicenter database for patients with cervical deformity (PCD) and the Nationwide Inpatient Sample (NIS).

    Study design/setting

    Retrospective review of prospective databases.

    Patient sample

    A total of 11,501 adult patients with cervical deformity (11,379 patients from the NIS and 122 patients from the PCD database).

    Outcome measures

    Perioperative medical and surgical complications.

    Methods

    The NIS was queried (2001-2013) for cervical deformity discharges for patients ≥18 years undergoing cervical fusions using International Classification of Disease, Ninth Revision (ICD-9) coding. Patients ≥18 years from the PCD database (2013-2015) were selected. Equivalent complications were identified and rates were compared. Bonferroni correction (p<.004) was used for Pearson chi-square. Binary logistic regression was used to evaluate differences in complication rates between databases.

    Results

    A total of 11,379 patients from the NIS database and 122 patiens from the PCD database were identified. Patients from the PCD database were older (62.49 vs. 55.15, p<.001) but displayed similar gender distribution. Intraoperative complication rate was higher in the PCD (39.3%) group than in the NIS (9.2%, p<.001) database. The PCD database had an increased risk of reporting overall complications than the NIS (odds ratio: 2.81, confidence interval: 1.81-4.38). Only device-related complications were greater in the NIS (7.1% vs. 1.1%, p=.007). Patients from the PCD database displayed higher rates of the following complications: peripheral vascular (0.8% vs. 0.1%, p=.001), gastrointestinal (GI) (2.5% vs. 0.2%, p<.001), infection (8.2% vs. 0.5%, p<.001), dural tear (4.1% vs. 0.6%, p<.001), and dysphagia (9.8% vs. 1.9%, p<.001). Genitourinary, wound, and deep veinthrombosis (DVT) complications were similar between databases (p>.004). Based on surgicalapproach, the PCD reported higher GI and neurologic complication rates for combined anterior-posterior procedures (p<.001). For posterior-only procedures, the NIS had more device-related complications (12.4% vs. 0.1%, p=.003), whereas PCD had more infections (9.3% vs. 0.7%, p<.001).

    Conclusions

    Analysis of the surgeon-maintained cervical database revealed higher overall and individual complication rates and higher data granularity. The nationwide database may underestimate complications of patients with adult cervical deformity (ACD) particularly in regard to perioperative surgical details owing to coding and deformity generalizations. The surgeon-maintained database captures the surgical details, but may underestimate some medical complications.
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    ItemOpen Access
    Primary Drivers of Adult Cervical Deformity: Prevalence, Variations in Presentation, and Effect of Surgical Treatment Strategies on Early Postoperative Alignment.
    (Neurosurgery, 2018-10) Passias, Peter G; Jalai, Cyrus M; Lafage, Virginie; Lafage, Renaud; Protopsaltis, Themistocles; Ramchandran, Subaraman; Horn, Samantha R; Poorman, Gregory W; Gupta, Munish; Hart, Robert A; Deviren, Vedat; Soroceanu, Alexandra; Smith, Justin S; Schwab, Frank; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study Group (Littleton, Colorado)

    Background

    Primary drivers (PDs) of adult cervical deformity (ACD) have not been described in relation to pre- and early postoperative alignment or degree of correction.

    Objective

    To define the PDs of ACD to understand the impact of driver region on global postoperative compensatory mechanisms.

    Methods

    Primary cervical deformity driver/vertebral apex level were determined: CS = cervical; CTJ = cervicothoracic junction; TH = thoracic; SP = spinopelvic. Patients were evaluated if surgery included PD apex, based on the lowest instrumented vertebra (LIV): CS: LIV ≤ C7, CTJ: LIV ≤ T3, TH: LIV ≤ T12. Cervical and thoracolumbar alignment was measured preoperatively and 3 mo (3M) postoperatively. PD groups were compared with analysis of variance/Pearson χ2, paired t-tests.

    Results

    Eighty-four ACD patients met inclusion criteria. Thoracic drivers (n = 26) showed greatest preoperative cervical and global malalignment against other PD: higher thoracic kyphosis, pelvic incidence-lumbar lordosis (PI-LL), T1 slope C2-T3 sagittal vertical axis (SVA), and C0-2 angle (P < .05). Differences in baseline-3M alignment changes were observed between surgical PD groups, in PI-LL, LL, T1 slope minus cervical lordosis (TS-CL), cervical SVA, C2-T3 SVA (P < .05). Main changes were between TH and CS driver groups: TH patients had greater PI-LL (4.47° vs -0.87°, P = .049), TS-CL (-19.12° vs -4.30, P = .050), C2-C7 SVA (-18.12 vs -4.30 mm, P = .007), and C2-T3 SVA (-24.76 vs 8.50 mm, P = .002) baseline-3M correction. CTJ drivers trended toward greater LL correction compared to CS drivers (-6.00° vs 0.88°, P = .050). Patients operated at CS driver level had a difference in the prevalence of 3M TS-CL modifier grades (0 = 35.7%, 1 = 0.0%, 2 = 13.3%, P = .030). There was a significant difference in 3M chin-brow vertical angle modifier grade distribution in TH drivers (0 = 0.0%, 1 = 35.9%, 2 = 14.3%, P = .049).

    Conclusion

    Characterizing ACD patients by PD type reveals differences in pre- and postoperative alignment. Evaluating surgical alignment outcomes based on PD inclusion is important in understanding alignment goals for ACD correction.
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    ItemOpen Access
    Prospective multi-centric evaluation of upper cervical and infra-cervical sagittal compensatory alignment in patients with adult cervical deformity.
    (European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, 2018-02) Ramchandran, Subaraman; Protopsaltis, Themistocles S; Sciubba, Daniel; Scheer, Justin K; Jalai, Cyrus M; Daniels, Alan; Passias, Peter G; Lafage, Virginie; Kim, Han Jo; Mundis, Gregory; Klineberg, Eric; Hart, Robert A; Smith, Justin S; Shaffrey, Christopher; Ames, Christopher P; International Spine Study Group
    PURPOSE:Reciprocal mechanisms for standing alignment have been described in thoraco-lumbar deformity but have not been studied in patients with primary cervical deformity (CD). The purpose of this study is to report upper- and infra-cervical sagittal compensatory mechanisms in patients with CD and evaluate their changes post-operatively. METHODS:Global spinal alignment was studied in a prospective database of operative CD patients. Inclusion criteria were any of the following: cervical kyphosis (CK) > 10°, cervical scoliosis > 10°, cSVA (C2-C7 Sagittal vertical axis) > 4 cm or CBVA (Chin Brow Vertical Angle) > 25°. For this study, patients who had previous fusion outside C2 to T4 segments were excluded. Patients were sub-classified by increasing severity of cervical kyphosis [CL (cervical lordosis): < 0°, CK-low 0°-10°, CK-high > 10°] and cSVA (cSVA-low 0-4 cm, cSVA-mid 4-6 cm, cSVA-high > 6 cm) and were compared for pre- and 3-month post-operative regional and global sagittal alignment to determine compensatory recruitment. RESULTS:75 CD patients (mean age 61.3 years, 56% women) were included. Patients with progressively larger CK had a progressive increase in C0-C2 (CL = 34°, CK-low = 37°, CK-high = 44°, p = 0.004), C2Slope and T1Slope-CL (p < 0.05). As the cSVA increased, there was progressive increase in C2Slope, T1Slope and TS-CL (p < 0.05) and patients compensated through increasing C0-C2 (cSVA-low = 33°, cSVA-mid = 40°, cSVA-high = 43°, p = 0.007) and pelvic tilt (cSVA-low = 14.9°, cSVA-mid = 24.1°, cSVA-high = 24.9°, p = 0.02). At 3 months post-op, with significant improvement in cervical alignment, there was relaxation of C0-C2 (39°-35°, p = 0.01) which positively correlated with magnitude of deformity correction. CONCLUSIONS:Patients with cervical malalignment compensate with upper cervical hyper-lordosis, presumably for the maintenance of horizontal gaze. As cSVA increases, patients also tend to exhibit increased pelvic retroversion. Following surgical treatment, there was relaxation of upper cervical compensation.
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    ItemOpen Access
    Prospective Multicenter Assessment of Early Complication Rates Associated With Adult Cervical Deformity Surgery in 78 Patients.
    (Neurosurgery, 2016-09) Smith, Justin S; Ramchandran, Subaraman; Lafage, Virginie; Shaffrey, Christopher I; Ailon, Tamir; Klineberg, Eric; Protopsaltis, Themistocles; Schwab, Frank J; OʼBrien, Michael; Hostin, Richard; Gupta, Munish; Mundis, Gregory; Hart, Robert; Kim, Han Jo; Passias, Peter G; Scheer, Justin K; Deviren, Vedat; Burton, Douglas C; Eastlack, Robert; Bess, Shay; Albert, Todd J; Riew, K Daniel; Ames, Christopher P; International Spine Study Group

    Background

    Few reports have focused on treatment of adult cervical deformity (ACD).

    Objective

    To present early complication rates associated with ACD surgery.

    Methods

    A prospective multicenter database of consecutive operative ACD patients was reviewed for early (≤30 days from surgery) complications. Enrollment required at least 1 of the following: cervical kyphosis >10 degrees, cervical scoliosis >10 degrees, C2-7 sagittal vertical axis >4 cm, or chin-brow vertical angle >25 degrees.

    Results

    Seventy-eight patients underwent surgical treatment for ACD (mean age, 60.8 years). Surgical approaches included anterior-only (14%), posterior-only (49%), anterior-posterior (35%), and posterior-anterior-posterior (3%). Mean numbers of fused anterior and posterior vertebral levels were 4.7 and 9.4, respectively. A total of 52 early complications were reported, including 26 minor and 26 major. Twenty-two (28.2%) patients had at least 1 minor complication, and 19 (24.4%) had at least 1 major complication. Overall, 34 (43.6%) patients had at least 1 complication. The most common complications included dysphagia (11.5%), deep wound infection (6.4%), new C5 motor deficit (6.4%), and respiratory failure (5.1%). One (1.3%) mortality occurred. Early complication rates differed significantly by surgical approach: anterior-only (27.3%), posterior-only (68.4%), and anterior-posterior/posterior-anterior-posterior (79.3%) (P = .007).

    Conclusion

    This report provides benchmark rates for overall and specific ACD surgery complications. Although the surgical approach(es) used were likely driven by the type and complexity of deformity, there were significantly higher complication rates associated with combined and posterior-only approaches compared with anterior-only approaches. These findings may prove useful in treatment planning, patient counseling, and ongoing efforts to improve safety of care.

    Abbreviations

    3CO, 3-column osteotomiesACD, adult cervical deformityEBL, estimated blood lossISSG, International Spine Study groupSVA, sagittal vertical axis.
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    ItemOpen Access
    The Importance of C2 Slope, a Singular Marker of Cervical Deformity, Correlates With Patient-reported Outcomes.
    (Spine, 2020-02) Protopsaltis, Themistocles S; Ramchandran, Subaraman; Tishelman, Jared C; Smith, Justin S; Neuman, Brian J; Jr, Gregory M Mundis; Lafage, Renaud; Klineberg, Eric O; Hamilton, D Kojo; LaFage, Virginie; Gupta, Munish C; Hart, Robert A; Schwab, Frank J; Burton, Douglas C; Bess, Shay; Shaffrey, Christopher I; Ames, Christopher P; International Spine Study Group

    Study design

    Retrospective review of a prospectively collected database.

    Objective

    To define a simplified singular measure of cervical deformity (CD), C2 slope (C2S), which correlates with postoperative outcomes.

    Summary of background data

    Sagittal malalignment of the cervical spine, defined by the cervical sagittal vertical axis (cSVA) has been associated with poor outcomes following surgical correction of the deformity. There has been a proliferation of parameters to describe CD. This added complexity can lead to confusion in classifying, treating, and assessing outcomes of CD surgery.

    Methods

    A prospective database of CD patients was analyzed. Inclusion criteria were cervical kyphosis>10°, cervical scoliosis>10°, cSVA>4 cm, or chin-brow vertical angle >25°. Patients were categorized into two groups and compared based on whether the apex of the deformity was in the cervical (C) or the cervicothoracic (CT) region. Radiographic parameters were correlated to C2S, T1 slope (T1S) and 1-year health-related quality-of-life outcomes as measured by the EuroQol 5 Dimension questionnaire (EQ5D), modified Japanese Orthopedic Association Scale, numeric rating scale for neck pain, and the Neck Disability Index (NDI).

    Results

    One hundred four CD patients (C = 74, CT = 30; mean age 61 yr, 56% women, 42% revisions) were included. CT patients had higher baseline cSVA and T1S (P < 0.05). C2S correlated with T1 slope minus cervical lordosis (TS-CL) (r = 0.98, P < 0.001) and C0-C2 angle, cSVA, CL, T1S (r = 0.37-0.65, P < 0.001). Correlation of cSVA with C0-C2 was weaker (r = 0.48, P < 0.001). At 1-year postoperatively, higher C2S correlated with worse EQ-5D (r = 0.28, P = 0.02); in CT patients, higher C2S correlated with worse NDI, modified Japanese Orthopedic Association Scale, numeric rating scale for neck pain, and EQ5D (all r > 0.5, P≤0.05). Using linear regression, moderate disability by EQ5D corresponded to C2S of 20°(r = 0.08). For CT patients, C2S = 17° corresponded to moderate disability by NDI (r = 0.4), and C2S = 20° by EQ5D (r = 0.25).

    Conclusion

    C2S correlated with upper-cervical and subaxial alignment. C2S correlated strongly with TS-CL (R = 0.98, P < 0.001) because C2S is a mathematical approximation of TS-CL. C2S is a useful marker of CD, linking the occipitocervical and cervico-thoracic spine. C2S defines the presence of a mismatch between cervical lordosis and thoracolumbar alignment. Worse 1-year postoperative C2 slope correlated with worse health outcomes.

    Level of evidence

    3.