Browsing by Author "Wang, Michael Y"

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    ItemOpen Access
    A Comparison of Minimally Invasive and Open Transforaminal Lumbar Interbody Fusion for Grade 1 Degenerative Lumbar Spondylolisthesis: An Analysis of the Prospective Quality Outcomes Database.
    (Neurosurgery, 2020-09) Chan, Andrew K; Bisson, Erica F; Bydon, Mohamad; Foley, Kevin T; Glassman, Steven D; Shaffrey, Christopher I; Wang, Michael Y; Park, Paul; Potts, Eric A; Shaffrey, Mark E; Coric, Domagoj; Knightly, John J; Fu, Kai-Ming; Slotkin, Jonathan R; Asher, Anthony L; Virk, Michael S; Kerezoudis, Panagiotis; Alvi, Mohammed A; Guan, Jian; Haid, Regis W; Mummaneni, Praveen V

    Background

    It remains unclear if minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is comparable to traditional, open TLIF because of the limitations of the prior small-sample-size, single-center studies reporting comparative effectiveness.

    Objective

    To compare MI-TLIF to traditional, open TLIF for grade 1 degenerative lumbar spondylolisthesis in the largest study to date by sample size.

    Methods

    We utilized the prospective Quality Outcomes Database registry and queried patients with grade 1 degenerative lumbar spondylolisthesis who underwent single-segment surgery with MI- or open TLIF methods. Outcomes were compared 24 mo postoperatively.

    Results

    A total of 297 patients were included: 72 (24.2%) MI-TLIF and 225 (75.8%) open TLIF. MI-TLIF surgeries had lower mean body mass indexes (29.5 ± 5.1 vs 31.3 ± 7.0, P = .0497) and more worker's compensation cases (11.1% vs 1.3%, P < .001) but were otherwise similar. MI-TLIF had less blood loss (108.8 ± 85.6 vs 299.6 ± 242.2 mL, P < .001), longer operations (228.2 ± 111.5 vs 189.6 ± 66.5 min, P < .001), and a higher return-to-work (RTW) rate (100% vs 80%, P = .02). Both cohorts improved significantly from baseline for 24-mo Oswestry Disability Index (ODI), Numeric Rating Scale back pain (NRS-BP), NRS leg pain (NRS-LP), and Euro-Qol-5 dimension (EQ-5D) (P > .001). In multivariable adjusted analyses, MI-TLIF was associated with lower ODI (β = -4.7; 95% CI = -9.3 to -0.04; P = .048), higher EQ-5D (β = 0.06; 95% CI = 0.01-0.11; P = .02), and higher satisfaction (odds ratio for North American Spine Society [NASS] 1/2 = 3.9; 95% CI = 1.4-14.3; P = .02). Though trends favoring MI-TLIF were evident for NRS-BP (P = .06), NRS-LP (P = .07), and reoperation rate (P = .13), these results did not reach statistical significance.

    Conclusion

    For single-level grade 1 degenerative lumbar spondylolisthesis, MI-TLIF was associated with less disability, higher quality of life, and higher patient satisfaction compared with traditional, open TLIF. MI-TLIF was associated with higher rates of RTW, less blood loss, but longer operative times. Though we utilized multivariable adjusted analyses, these findings may be susceptible to selection bias.
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    ItemOpen Access
    A comparison of minimally invasive transforaminal lumbar interbody fusion and decompression alone for degenerative lumbar spondylolisthesis.
    (Neurosurgical focus, 2019-05) Chan, Andrew K; Bisson, Erica F; Bydon, Mohamad; Glassman, Steven D; Foley, Kevin T; Potts, Eric A; Shaffrey, Christopher I; Shaffrey, Mark E; Coric, Domagoj; Knightly, John J; Park, Paul; Wang, Michael Y; Fu, Kai-Ming; Slotkin, Jonathan R; Asher, Anthony L; Virk, Michael S; Kerezoudis, Panagiotis; Alvi, Mohammed Ali; Guan, Jian; Haid, Regis W; Mummaneni, Praveen V
    OBJECTIVEThe optimal minimally invasive surgery (MIS) approach for grade 1 lumbar spondylolisthesis is not clearly elucidated. In this study, the authors compared the 24-month patient-reported outcomes (PROs) after MIS transforaminal lumbar interbody fusion (TLIF) and MIS decompression for degenerative lumbar spondylolisthesis.METHODSA total of 608 patients from 12 high-enrolling sites participating in the Quality Outcomes Database (QOD) lumbar spondylolisthesis module underwent single-level surgery for degenerative grade 1 lumbar spondylolisthesis, of whom 143 underwent MIS (72 MIS TLIF [50.3%] and 71 MIS decompression [49.7%]). Surgeries were classified as MIS if there was utilization of percutaneous screw fixation and placement of a Wiltse plane MIS intervertebral body graft (MIS TLIF) or if there was a tubular decompression (MIS decompression). Parameters obtained at baseline through at least 24 months of follow-up were collected. PROs included the Oswestry Disability Index (ODI), numeric rating scale (NRS) for back pain, NRS for leg pain, EuroQol-5D (EQ-5D) questionnaire, and North American Spine Society (NASS) satisfaction questionnaire. Multivariate models were constructed to adjust for patient characteristics, surgical variables, and baseline PRO values.RESULTSThe mean age of the MIS cohort was 67.1 ± 11.3 years (MIS TLIF 62.1 years vs MIS decompression 72.3 years) and consisted of 79 (55.2%) women (MIS TLIF 55.6% vs MIS decompression 54.9%). The proportion in each cohort reaching the 24-month follow-up did not differ significantly between the cohorts (MIS TLIF 83.3% and MIS decompression 84.5%, p = 0.85). MIS TLIF was associated with greater blood loss (mean 108.8 vs 33.0 ml, p < 0.001), longer operative time (mean 228.2 vs 101.8 minutes, p < 0.001), and longer length of hospitalization (mean 2.9 vs 0.7 days, p < 0.001). MIS TLIF was associated with a significantly lower reoperation rate (14.1% vs 1.4%, p = 0.004). Both cohorts demonstrated significant improvements in ODI, NRS back pain, NRS leg pain, and EQ-5D at 24 months (p < 0.001, all comparisons relative to baseline). In multivariate analyses, MIS TLIF-as opposed to MIS decompression alone-was associated with superior ODI change (β = -7.59, 95% CI -14.96 to -0.23; p = 0.04), NRS back pain change (β = -1.54, 95% CI -2.78 to -0.30; p = 0.02), and NASS satisfaction (OR 0.32, 95% CI 0.12-0.82; p = 0.02).CONCLUSIONSFor symptomatic, single-level degenerative spondylolisthesis, MIS TLIF was associated with a lower reoperation rate and superior outcomes for disability, back pain, and patient satisfaction compared with posterior MIS decompression alone. This finding may aid surgical decision-making when considering MIS for degenerative lumbar spondylolisthesis.
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    ItemOpen Access
    Are Minimally Invasive Spine Surgeons or Classical Open Spine Surgeons More Consistent with Their Treatment of Adult Spinal Deformity?
    (World neurosurgery, 2022-09) Uribe, Juan S; Koffie, Robert M; Wang, Michael Y; Mundis, Gregory M; Kanter, Adam S; Eastlack, Robert K; Anand, Neel; Park, Paul; Smith, Justin S; Burton, Douglas C; Chou, Dean; Kelly, Michael P; Kim, Han Jo; Bess, Shay; Shaffrey, Christopher I; Schwab, Frank J; Lenke, Lawrence G; Mummaneni, Praveen V

    Objective

    Spine surgeons have a heuristic sense of how to surgically restore alignment and address adult spinal deformity (ASD) symptoms, but consensus on the extent of treatment remains unclear. We sought to determine the variability of surgical approaches in treating ASD.

    Methods

    Sixteen spine surgeons were surveyed on treatment approaches in 10 select ASD cases. We repeated the survey with the same surgeons 4 weeks later, with cases ordered differently. We examined the variability in length of construct, use of interbody spacers, osteotomies, and pelvic fixation frequency.

    Results

    Treatment approaches for each case varied by surgeon, with some surgeons opting for long fusion constructs in cases for which others offered no surgery. There was no consensus among surgeons on the number of levels fused, interbody spacer use, or anterior/posterior osteotomies. Intersurgeon and intrasurgeon variability was 48% (kappa = 0.31) and 59% (kappa = 0.44) for surgeons performing minimally invasive surgery (MIS) versus 37% (kappa = 0.21) and 47% (kappa = 0.30) for those performing open surgery. In the second-round survey, 8 of 15 (53%) surgeons substantially changed the construct length, number of interbody spacers, and osteotomies in at least half the cases they previously reviewed. Surgeons performing MIS versus open surgery were less likely to extend constructs to the pelvis (42.5% vs. 67.5%; P = 0.02), but construct length was not correlated with whether a surgeon performed MIS or open surgery.

    Conclusions

    Spinal deformity surgeons lack consensus on the optimal surgical approach for treating ASD. Classifying surgeons as performing MIS or open surgery does not mitigate this variability.
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    ItemOpen Access
    Assessing the differences in characteristics of patients lost to follow-up at 2 years: results from the Quality Outcomes Database study on outcomes of surgery for grade I spondylolisthesis.
    (Journal of neurosurgery. Spine, 2020-02) Bisson, Erica F; Mummaneni, Praveen V; Knightly, John; Alvi, Mohammed Ali; Goyal, Anshit; Chan, Andrew K; Guan, Jian; Biase, Michael; Strauss, Andrea; Glassman, Steven; Foley, Kevin; Slotkin, Jonathan R; Potts, Eric; Shaffrey, Mark; Shaffrey, Christopher I; Haid, Regis W; Fu, Kai-Ming; Wang, Michael Y; Park, Paul; Asher, Anthony L; Bydon, Mohamad
    OBJECTIVE:Loss to follow-up has been shown to bias outcomes assessment among studies utilizing clinical registries. Here, the authors analyzed patients enrolled in a national surgical registry and compared the baseline characteristics of patients captured with those lost to follow-up at 2 years. METHODS:The authors queried the Quality Outcomes Database for patients with grade I lumbar degenerative spondylolisthesis undergoing a surgical intervention between July 2014 and June 2016. Only those patients enrolled in a multisite study investigating the impact of fusion on clinical and patient-reported outcomes (PROs) among patients with grade I spondylolisthesis were evaluated. RESULTS:Of the 608 patients enrolled in the study undergoing 1- or 2-level decompression (23.0%, n = 140) or 1-level fusion (77.0%, n = 468), 14.5% (n = 88) were lost to follow-up at 2 years. Patients who were lost to follow-up were more likely to be younger (59.6 ± 13.5 vs 62.6 ± 11.7 years, p = 0.031), be employed (unemployment rate: 53.3% [n = 277] for successful follow-up vs 40.9% [n = 36] for those lost to follow-up, p = 0.017), have anxiety (26.1% [n = 23] vs 16.3% [n = 85], p = 0.026), have higher back pain scores (7.4 ± 2.9 vs 6.6 ± 2.8, p = 0.010), have higher leg pain scores (7.4 ± 2.5 vs 6.4 ± 2.9, p = 0.003), have higher Oswestry Disability Index scores (50.8 ± 18.7 vs 46 ± 16.8, p = 0.018), and have lower EQ-5D scores (0.481 ± 0.2 vs 0.547 ± 0.2, p = 0.012) at baseline. CONCLUSIONS:To execute future, high-quality studies, it is important to identify patients undergoing surgery for spondylolisthesis who might be lost to follow-up. In a large, prospective registry, the authors found that those lost to follow-up were more likely to be younger, be employed, have anxiety disorder, and have worse PRO scores.
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    ItemOpen Access
    Can a Minimal Clinically Important Difference Be Achieved in Elderly Patients with Adult Spinal Deformity Who Undergo Minimally Invasive Spinal Surgery?
    (World neurosurgery, 2016-02) Park, Paul; Okonkwo, David O; Nguyen, Stacie; Mundis, Gregory M; Than, Khoi D; Deviren, Vedat; La Marca, Frank; Fu, Kai-Ming; Wang, Michael Y; Uribe, Juan S; Anand, Neel; Fessler, Richard; Nunley, Pierce D; Chou, Dean; Kanter, Adam S; Shaffrey, Christopher I; Akbarnia, Behrooz A; Passias, Peter G; Eastlack, Robert K; Mummaneni, Praveen V; International Spine Study Group

    Background

    Older age has been considered a relative contraindication to complex spinal procedures. Minimally invasive surgery (MIS) techniques to treat patients with adult spinal deformity (ASD) have emerged with the potential benefit of decreased approach-related morbidity.

    Objective

    To determine whether a minimal clinically important difference (MCID) could be achieved in patients ages ≥ 65 years with ASD who underwent MIS.

    Methods

    Multicenter database of patients who underwent MIS for ASD was queried. Outcome metrics assessed were Oswestry Disability Index (ODI) and visual analog scale (VAS) scores for back and leg pain. On the basis of published reports, MCID was defined as a positive change of 12.8 ODI, 1.2 VAS back pain, and 1.6 VAS leg pain.

    Results

    Forty-two patients were identified. Mean age was 70.3 years; 31 (73.8%) were women. Preoperatively, mean coronal curve, pelvic tilt, pelvic incidence to lumbar lordosis mismatch, and sagittal vertical axis were 35°, 24.6°, 14.2°, and 4.7 cm, respectively. Postoperatively, mean coronal curve, pelvic tilt, pelvic incidence to lumbar lordosis, and sagittal vertical axis were 18°, 25.4°, 11.9°, and 4.9 cm, respectively. A mean of 5.0 levels was treated posteriorly, and a mean of 4.0 interbody fusions was performed. Mean ODI improved from 47.1 to 25.1. Mean VAS back and leg pain scores improved from 6.8 and 5.9 to 2.7 and 2.7, respectively. Mean follow-up was 32.1 months. For ODI, 64.3% of patients achieved MCID. For VAS back and leg pain, 82.9% and 72.2%, respectively, reached MCID.

    Conclusions

    MCID represents the threshold at which patients feel a meaningful clinical improvement has occurred. Our study results suggest that the majority of elderly patients with modest ASD can achieve MCID with MIS.
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    ItemOpen Access
    Cervical laminoplasty versus laminectomy and posterior cervical fusion for cervical myelopathy: propensity-matched analysis of 24-month outcomes from the Quality Outcomes Database.
    (Journal of neurosurgery. Spine, 2023-08) Yang, Eunice; Mummaneni, Praveen V; Chou, Dean; Bydon, Mohamad; Bisson, Erica F; Shaffrey, Christopher I; Gottfried, Oren N; Asher, Anthony L; Coric, Domagoj; Potts, Eric A; Foley, Kevin T; Wang, Michael Y; Fu, Kai-Ming; Virk, Michael S; Knightly, John J; Meyer, Scott; Park, Paul; Upadhyaya, Cheerag D; Shaffrey, Mark E; Buchholz, Avery L; Tumialán, Luis M; Turner, Jay D; Michalopoulos, Giorgos D; Sherrod, Brandon A; Agarwal, Nitin; Haid, Regis W; Chan, Andrew K

    Objective

    Compared with laminectomy with posterior cervical fusion (PCF), cervical laminoplasty (CL) may result in different outcomes for those operated on for cervical spondylotic myelopathy (CSM). The aim of this study was to compare 24-month patient-reported outcomes (PROs) for laminoplasty versus PCF by using the Quality Outcomes Database (QOD) CSM data set.

    Methods

    This was a retrospective study using an augmented data set from the prospectively collected QOD Registry Cervical Module. Patients undergoing laminoplasty or PCF for CSM were included. Using the nearest-neighbor method, the authors performed 1:1 propensity matching based on age, operated levels, and baseline modified Japanese Orthopaedic Association (mJOA) and visual analog scale (VAS) neck pain scores. The 24-month PROs, i.e., mJOA, Neck Disability Index (NDI), VAS neck pain, VAS arm pain, EQ-5D, EQ-VAS, and North American Spine Society (NASS) satisfaction scores, were compared. Only cases in the subaxial cervical region were included; those that crossed the cervicothoracic junction were excluded.

    Results

    From the 1141 patients included in the QOD CSM data set who underwent anterior or posterior surgery for cervical myelopathy, 946 (82.9%) had 24 months of follow-up. Of these, 43 patients who underwent laminoplasty and 191 who underwent PCF met the inclusion criteria. After matching, the groups were similar for baseline characteristics, including operative levels (CL group: 4.0 ± 0.9 vs PCF group: 4.2 ± 1.1, p = 0.337) and baseline PROs (p > 0.05), except for a higher percentage involved in activities outside the home in the CL group (95.3% vs 81.4%, p = 0.044). The 24-month follow-up for the matched cohorts was similar (CL group: 88.4% vs PCF group: 83.7%, p = 0.534). Patients undergoing laminoplasty had significantly lower estimated blood loss (99.3 ± 91.7 mL vs 186.7 ± 142.7 mL, p = 0.003), decreased length of stay (3.0 ± 1.6 days vs 4.5 ± 3.3 days, p = 0.012), and a higher rate of routine discharge (88.4% vs 62.8%, p = 0.006). The CL cohort also demonstrated a higher rate of return to activities (47.2% vs 21.2%, p = 0.023) after 3 months. Laminoplasty was associated with a larger improvement in 24-month NDI score (-19.6 ± 18.9 vs -9.1 ± 21.9, p = 0.031). Otherwise, there were no 3- or 24-month differences in mJOA, mean NDI, VAS neck pain, VAS arm pain, EQ-5D, EQ-VAS, and distribution of NASS satisfaction scores (p > 0.05) between the cohorts.

    Conclusions

    Compared with PCF, laminoplasty was associated with decreased blood loss, decreased length of hospitalization, and higher rates of home discharge. At 3 months, laminoplasty was associated with a higher rate of return to baseline activities. At 24 months, laminoplasty was associated with greater improvements in neck disability. Otherwise, laminoplasty and PCF shared similar outcomes for functional status, pain, quality of life, and satisfaction. Laminoplasty and PCF achieved similar neck pain scores, suggesting that moderate preoperative neck pain may not necessarily be a contraindication for laminoplasty.
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    ItemOpen Access
    Cervical spondylotic myelopathy and driving abilities: defining the prevalence and long-term postoperative outcomes using the Quality Outcomes Database.
    (Journal of neurosurgery. Spine, 2024-02) Agarwal, Nitin; Johnson, Sarah E; Bydon, Mohamad; Bisson, Erica F; Chan, Andrew K; Shabani, Saman; Letchuman, Vijay; Michalopoulos, Giorgos D; Lu, Daniel C; Wang, Michael Y; Lavadi, Raj Swaroop; Haid, Regis W; Knightly, John J; Sherrod, Brandon A; Gottfried, Oren N; Shaffrey, Christopher I; Goldberg, Jacob L; Virk, Michael S; Hussain, Ibrahim; Glassman, Steven D; Shaffrey, Mark E; Park, Paul; Foley, Kevin T; Pennicooke, Brenton; Coric, Domagoj; Slotkin, Jonathan R; Upadhyaya, Cheerag; Potts, Eric A; Tumialán, Luis M; Chou, Dean; Fu, Kai-Ming G; Asher, Anthony L; Mummaneni, Praveen V

    Objective

    Cervical spondylotic myelopathy (CSM) can cause significant difficulty with driving and a subsequent reduction in an individual's quality of life due to neurological deterioration. The positive impact of surgery on postoperative patient-reported driving capabilities has been seldom explored.

    Methods

    The CSM module of the Quality Outcomes Database was utilized. Patient-reported driving ability was assessed via the driving section of the Neck Disability Index (NDI) questionnaire. This is an ordinal scale in which 0 represents the absence of symptoms while driving and 5 represents a complete inability to drive due to symptoms. Patients were considered to have an impairment in their driving ability if they reported an NDI driving score of 3 or higher (signifying impairment in driving duration due to symptoms). Multivariable logistic regression models were fitted to evaluate mediators of baseline impairment and improvement at 24 months after surgery, which was defined as an NDI driving score < 3.

    Results

    A total of 1128 patients who underwent surgical intervention for CSM were included, of whom 354 (31.4%) had baseline driving impairment due to CSM. Moderate (OR 2.3) and severe (OR 6.3) neck pain, severe arm pain (OR 1.6), mild-moderate (OR 2.1) and severe (OR 2.5) impairment in hand/arm dexterity, severe impairment in leg use/walking (OR 1.9), and severe impairment of urinary function (OR 1.8) were associated with impaired driving ability at baseline. Of the 291 patients with baseline impairment and available 24-month follow-up data, 209 (71.8%) reported postoperative improvement in their driving ability. This improvement seemed to be mediated particularly through the achievement of the minimal clinically important difference (MCID) in neck pain and improvement in leg function/walking. Patients with improved driving at 24 months noted higher postoperative satisfaction (88.5% vs 62.2%, p < 0.01) and were more likely to achieve a clinically significant improvement in their quality of life (50.7% vs 37.8%, p < 0.01).

    Conclusions

    Nearly one-third of patients with CSM report impaired driving ability at presentation. Seventy-two percent of these patients reported improvements in their driving ability within 24 months of surgery. Surgical management of CSM can significantly improve patients' driving abilities at 24 months and hence patients' quality of life.
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    ItemOpen Access
    Cervical spondylotic myelopathy with severe axial neck pain: is anterior or posterior approach better?
    (Journal of neurosurgery. Spine, 2023-01) Chan, Andrew K; Shaffrey, Christopher I; Gottfried, Oren N; Park, Christine; Than, Khoi D; Bisson, Erica F; Bydon, Mohamad; Asher, Anthony L; Coric, Domagoj; Potts, Eric A; Foley, Kevin T; Wang, Michael Y; Fu, Kai-Ming; Virk, Michael S; Knightly, John J; Meyer, Scott; Park, Paul; Upadhyaya, Cheerag; Shaffrey, Mark E; Buchholz, Avery L; Tumialán, Luis M; Turner, Jay D; Michalopoulos, Giorgos D; Sherrod, Brandon A; Agarwal, Nitin; Chou, Dean; Haid, Regis W; Mummaneni, Praveen V

    Objective

    The aim of this study was to determine whether multilevel anterior cervical discectomy and fusion (ACDF) or posterior cervical laminectomy and fusion (PCLF) is superior for patients with cervical spondylotic myelopathy (CSM) and high preoperative neck pain.

    Methods

    This was a retrospective study of prospectively collected data using the Quality Outcomes Database (QOD) CSM module. Patients who received a subaxial fusion of 3 or 4 segments and had a visual analog scale (VAS) neck pain score of 7 or greater at baseline were included. The 3-, 12-, and 24-month outcomes were compared for patients undergoing ACDF with those undergoing PCLF.

    Results

    Overall, 1141 patients with CSM were included in the database. Of these, 495 (43.4%) presented with severe neck pain (VAS score > 6). After applying inclusion and exclusion criteria, we compared 65 patients (54.6%) undergoing 3- and 4-level ACDF and 54 patients (45.4%) undergoing 3- and 4-level PCLF. Patients undergoing ACDF had worse Neck Disability Index scores at baseline (52.5 ± 15.9 vs 45.9 ± 16.8, p = 0.03) but similar neck pain (p > 0.05). Otherwise, the groups were well matched for the remaining baseline patient-reported outcomes. The rates of 24-month follow-up for ACDF and PCLF were similar (86.2% and 83.3%, respectively). At the 24-month follow-up, both groups demonstrated mean improvements in all outcomes, including neck pain (p < 0.05). In multivariable analyses, there was no significant difference in the degree of neck pain change, rate of neck pain improvement, rate of pain-free achievement, and rate of reaching minimal clinically important difference (MCID) in neck pain between the two groups (adjusted p > 0.05). However, ACDF was associated with a higher 24-month modified Japanese Orthopaedic Association scale (mJOA) score (β = 1.5 [95% CI 0.5-2.6], adjusted p = 0.01), higher EQ-5D score (β = 0.1 [95% CI 0.01-0.2], adjusted p = 0.04), and higher likelihood for return to baseline activities (OR 1.2 [95% CI 1.1-1.4], adjusted p = 0.002).

    Conclusions

    Severe neck pain is prevalent among patients undergoing surgery for CSM, affecting more than 40% of patients. Both ACDF and PCLF achieved comparable postoperative neck pain improvement 3, 12, and 24 months following 3- or 4-segment surgery for patients with CSM and severe neck pain. However, multilevel ACDF was associated with superior functional status, quality of life, and return to baseline activities at 24 months in multivariable adjusted analyses.
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    ItemOpen Access
    Characteristics of patients who return to work after undergoing surgery for cervical spondylotic myelopathy: a Quality Outcomes Database study.
    (Journal of neurosurgery. Spine, 2023-05) Bergin, Stephen M; Michalopoulos, Giorgos D; Shaffrey, Christopher I; Gottfried, Oren N; Johnson, Eli; Bisson, Erica F; Wang, Michael Y; Knightly, John J; Virk, Michael S; Tumialán, Luis M; Turner, Jay D; Upadhyaya, Cheerag D; Shaffrey, Mark E; Park, Paul; Foley, Kevin T; Coric, Domagoj; Slotkin, Jonathan R; Potts, Eric A; Chou, Dean; Fu, Kai-Ming G; Haid, Regis W; Asher, Anthony L; Bydon, Mohamad; Mummaneni, Praveen V; Than, Khoi D

    Objective

    Return to work (RTW) is an important surgical outcome for patients who are employed, yet a significant number of patients with cervical spondylotic myelopathy (CSM) who are employed undergo cervical spine surgery and fail to RTW. In this study, the authors investigated factors associated with failure to RTW in the CSM population who underwent cervical spine surgery and who were considered to have a good surgical outcome yet failed to RTW.

    Methods

    This study retrospectively analyzed prospectively collected data from the cervical myelopathy module of a national spine registry, the Quality Outcomes Database. The CSM data set of the Quality Outcomes Database was queried for patients who were employed at the time of surgery and planned to RTW postoperatively. Distinct multivariable logistic regression models were fitted with 3-month RTW as an outcome for the overall population to identify risk factors for failure to RTW. Good outcomes were defined as patients who had no adverse events (readmissions or complications), who had achieved 30% improvement in Neck Disability Index score, and who were satisfied (North American Spine Society satisfaction score of 1 or 2) at 3 months postsurgery.

    Results

    Of the 409 patients who underwent surgery, 80% (n = 327) did RTW at 3 months after surgery. At 3 months, 56.9% of patients met the criteria for a good surgical outcome, and patients with a good outcome were more likely to RTW (88.1% vs 69.2%, p < 0.01). Of patients with a good outcome, 11.9% failed to RTW at 3 months. Risk factors for failing to RTW despite a good outcome included preoperative short-term disability or leave status (OR 3.03 [95% CI 1.66-7.90], p = 0.02); a higher baseline Neck Disability Index score (OR 1.41 [95% CI 1.09-1.84], p < 0.01); and higher neck pain score at 3 months postoperatively (OR 0.81 [95% CI 0.66-0.99], p = 0.04).

    Conclusions

    Most patients with CSM who undergo spine surgery reenter the workforce within 3 months from surgery, with RTW rates being higher among patients who experience good outcomes. Among patients with good outcomes who were employed, failure to RTW was associated with being on preoperative short-term disability or leave status prior to surgery as well as higher neck pain scores at baseline and at 3 months postoperatively.
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    ItemOpen Access
    Classifying Patients Operated for Spondylolisthesis: A K-Means Clustering Analysis of Clinical Presentation Phenotypes.
    (Neurosurgery, 2021-11) Chan, Andrew K; Wozny, Thomas A; Bisson, Erica F; Pennicooke, Brenton H; Bydon, Mohamad; Glassman, Steven D; Foley, Kevin T; Shaffrey, Christopher I; Potts, Eric A; Shaffrey, Mark E; Coric, Domagoj; Knightly, John J; Park, Paul; Wang, Michael Y; Fu, Kai-Ming; Slotkin, Jonathan R; Asher, Anthony L; Virk, Michael S; Kerezoudis, Panagiotis; Alvi, Mohammed A; Guan, Jian; Haid, Regis W; Mummaneni, Praveen V

    Background

    Trials of lumbar spondylolisthesis are difficult to compare because of the heterogeneity in the populations studied.

    Objective

    To define patterns of clinical presentation.

    Methods

    This is a study of the prospective Quality Outcomes Database spondylolisthesis registry, including patients who underwent single-segment surgery for grade 1 degenerative lumbar spondylolisthesis. Twenty-four-month patient-reported outcomes (PROs) were collected. A k-means clustering analysis-an unsupervised machine learning algorithm-was used to identify clinical presentation phenotypes.

    Results

    Overall, 608 patients were identified, of which 507 (83.4%) had 24-mo follow-up. Clustering revealed 2 distinct cohorts. Cluster 1 (high disease burden) was younger, had higher body mass index (BMI) and American Society of Anesthesiologist (ASA) grades, and globally worse baseline PROs. Cluster 2 (intermediate disease burden) was older and had lower BMI and ASA grades, and intermediate baseline PROs. Baseline radiographic parameters were similar (P > .05). Both clusters improved clinically (P < .001 all 24-mo PROs). In multivariable adjusted analyses, mean 24-mo Oswestry Disability Index (ODI), Numeric Rating Scale Back Pain (NRS-BP), Numeric Rating Scale Leg Pain, and EuroQol-5D (EQ-5D) were markedly worse for the high-disease-burden cluster (adjusted-P < .001). However, the high-disease-burden cluster demonstrated greater 24-mo improvements for ODI, NRS-BP, and EQ-5D (adjusted-P < .05) and a higher proportion reaching ODI minimal clinically important difference (MCID) (adjusted-P = .001). High-disease-burden cluster had lower satisfaction (adjusted-P = .02).

    Conclusion

    We define 2 distinct phenotypes-those with high vs intermediate disease burden-operated for lumbar spondylolisthesis. Those with high disease burden were less satisfied, had a lower quality of life, and more disability, more back pain, and more leg pain than those with intermediate disease burden, but had greater magnitudes of improvement in disability, back pain, quality of life, and more often reached ODI MCID.
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    ItemOpen Access
    Clinical and radiographic parameters associated with best versus worst clinical outcomes in minimally invasive spinal deformity surgery.
    (Journal of neurosurgery. Spine, 2016-07) Than, Khoi D; Park, Paul; Fu, Kai-Ming; Nguyen, Stacie; Wang, Michael Y; Chou, Dean; Nunley, Pierce D; Anand, Neel; Fessler, Richard G; Shaffrey, Christopher I; Bess, Shay; Akbarnia, Behrooz A; Deviren, Vedat; Uribe, Juan S; La Marca, Frank; Kanter, Adam S; Okonkwo, David O; Mundis, Gregory M; Mummaneni, Praveen V; International Spine Study Group
    OBJECTIVE 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. METHODS 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. RESULTS 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). CONCLUSIONS 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.
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    ItemOpen Access
    Comparative analysis of patient-reported outcomes in myelopathy and myeloradiculopathy: a Quality Outcomes Database study.
    (Journal of neurosurgery. Spine, 2024-09) Porche, Ken; Bisson, Erica F; Sherrod, Brandon; Dru, Alexander; Chan, Andrew K; Shaffrey, Christopher I; Gottfried, Oren N; Bydon, Mohamad; Asher, Anthony L; Coric, Domagoj; Potts, Eric A; Foley, Kevin T; Wang, Michael Y; Fu, Kai-Ming; Virk, Michael S; Knightly, John J; Meyer, Scott; Upadhyaya, Cheerag D; Shaffrey, Mark E; Uribe, Juan S; Tumialán, Luis M; Turner, Jay D; Chou, Dean; Haid, Regis W; Mummaneni, Praveen V; Park, Paul
    Myelopathy in the cervical spine can present with diverse symptoms, many of which can be debilitating for patients. Patients with radiculopathy symptoms demonstrate added complexity because of the overlapping symptoms and treatment considerations. The authors sought to assess outcomes in patients with myelopathy presenting with or without concurrent radiculopathy. The Quality Outcomes Database, a prospectively collected multi-institutional database, was used to analyze demographic, clinical, and surgical variables of patients presenting with myelopathy or myeloradiculopathy as a result of degenerative pathology. Outcome measures included arm (VAS-arm) and neck (VAS-neck) visual analog scale (VAS) scores, modified Japanese Orthopaedic Association (mJOA) scale score, EuroQol VAS (EQ-VAS) score, and Neck Disability Index (NDI) at 3, 12, and 24 months compared with baseline. A total of 1015 patients were included in the study: 289 patients with myelopathy alone (M0), 239 with myeloradiculopathy but no arm pain (MRAP-), and 487 patients with myeloradiculopathy and arm pain (MRAP+). M0 patients were older than the myeloradiculopathy cohorts combined (M0 64.2 vs MRAP- + MRAP+ 59.5 years, p < 0.001), whereas MRAP+ patients had higher BMI and a greater incidence of current smoking compared with the other cohorts. There were more anterior approaches used in in MRAP+ patients and more posterior approaches used in M0 patients. In severely myelopathic patients (mJOA scale score ≤ 10), posterior approaches were used more often for M0 (p < 0.0001) and MRAP+ (p < 0.0001) patients. Patients with myelopathy and myeloradiculopathy both exhibited significant improvement at 1 and 2 years across all outcome domains. The amount of improvement did not vary based on surgical approach. In comparing cohort outcomes, postoperative outcome differences were associated with patient-reported scores at baseline. Patients with myelopathy and those with myeloradiculopathy demonstrated significant and similar improvement in arm and neck pain scores, myelopathy, disability, and quality of life at 3 months that was sustained at 1- and 2-year follow-up intervals. More radicular symptoms and arm pain increased the likelihood of a surgeon choosing an anterior approach, whereas more severe myelopathy increased the likelihood of approaching posteriorly. Surgical approach itself was not an independent predictor of outcome.
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    ItemOpen Access
    Comparison of Complications and Clinical and Radiographic Outcomes Between Nonobese and Obese Patients with Adult Spinal Deformity Undergoing Minimally Invasive Surgery.
    (World neurosurgery, 2016-03) Park, Paul; Wang, Michael Y; Nguyen, Stacie; Mundis, Gregory M; La Marca, Frank; Uribe, Juan S; Anand, Neel; Okonkwo, David O; Kanter, Adam S; Fessler, Richard; Eastlack, Robert K; Chou, Dean; Deviren, Vedat; Nunley, Pierce D; Shaffrey, Christopher I; Mummaneni, Praveen V; International Spine Study Group

    Objective

    Obesity can be associated with increased complications and potentially worse outcomes. We aimed to evaluate the impact of obesity on complications and outcomes in patients with adult spinal deformity (ASD) who underwent minimally invasive surgery (MIS).

    Methods

    A multicenter database of patients with ASD treated via MIS was queried. Of 190 patients in the database, 77 fit the inclusion criteria of 3 or more spinal levels treated minimally invasively. Patients were divided by body mass index (BMI) <30 (nonobese; n = 59) and BMI ≥ 30 (obese; n = 18).

    Results

    Mean BMI was 24.6 nonobese and 35.0 obese (P < 0.001). There were mean 3.8 interbody fusions nonobese and 4.7 obese (P = 0.065). Levels treated posteriorly averaged 5.8 nonobese and 5.9 obese (P = 0.502). Mean follow-up was 34.4 months nonobese and 35.3 months obese (P = 0.976). Baseline radiographic parameters were similar between groups. Postoperatively, SVA averaged 83.9 mm obese and 20.4 mm nonobese (P = 0.002). Postoperative lumbar lordosis-pelvic incidence mismatch averaged 17.9° obese and 9.9° nonobese (P = 0.028). Both groups had improvement in Oswestry Disability Index (ODI) scores with no difference in postoperative ODI scores between groups (P = 0.090). Similarly, both groups had decreased VAS scores for back and leg pain with no difference between groups postoperatively. Twenty (33.9%) nonobese patients versus 7 (38.9%) obese patients had complications (P = 0.452).

    Conclusions

    Our results suggest that obesity does not negatively impact complication rate or clinical outcomes in patients with ASD treated via MIS approaches.
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    ItemOpen Access
    Comparison of radiographic results after minimally invasive, hybrid, and open surgery for adult spinal deformity: a multicenter study of 184 patients.
    (Neurosurgical focus, 2014-05) Haque, Raqeeb M; Mundis, Gregory M; Ahmed, Yousef; El Ahmadieh, Tarek Y; Wang, Michael Y; Mummaneni, Praveen V; Uribe, Juan S; Okonkwo, David O; Eastlack, Robert K; Anand, Neel; Kanter, Adam S; La Marca, Frank; Akbarnia, Behrooz A; Park, Paul; Park, Paul; Lafage, Virginie; Terran, Jamie S; Shaffrey, Christopher I; Klineberg, Eric; Deviren, Vedat; Fessler, Richard G; International Spine Study Group

    Object

    Various surgical approaches, including open, minimally invasive, and hybrid techniques, have gained momentum in the management of adult spinal deformity. However, few data exist on the radiographic outcomes of different surgical techniques. The objective of this study was to compare the radiographic and clinical outcomes of the surgical techniques used in the treatment of adult spinal deformity.

    Methods

    The authors conducted a retrospective review of two adult spinal deformity patient databases, a prospective open surgery database and a retrospective minimally invasive surgery (MIS) and hybrid surgery database. The time frame of enrollment in this study was from 2007 to 2012. Spinal deformity patients were stratified into 3 surgery groups: MIS, hybrid surgery, and open surgery. The following pre- and postoperative radiographic parameters were assessed: lumbar major Cobb angle, lumbar lordosis, pelvic incidence minus lumbar lordosis (PI-LL), sagittal vertical axis, and pelvic tilt. Scores on the Oswestry Disability Index (ODI) and a visual analog scale (VAS) for both back and leg pain were also obtained from each patient.

    Results

    Of the 234 patients with adult spinal deformity, 184 patients had pre- and postoperative radiographs and were thus included in the study (MIS, n = 42; hybrid, n = 33; open, n = 109). Patients were a mean of 61.7 years old and had a mean body mass index of 26.9 kg/m(2). Regarding radiographic outcomes, the MIS group maintained a significantly smaller mean lumbar Cobb angle (13.1°) after surgery compared with the open group (20.4°, p = 0.002), while the hybrid group had a significantly larger lumbar curve correction (26.6°) compared with the MIS group (18.8°, p = 0.045). The mean change in the PI-LL was larger for the hybrid group (20.6°) compared with the open (10.2°, p = 0.023) and MIS groups (5.5°, p = 0.003). The mean sagittal vertical axis correction was greater for the open group (25 mm) compared with the MIS group (≤ 1 mm, p = 0.008). Patients in the open group had a significantly larger postoperative thoracic kyphosis (41.45°) compared with the MIS patients (33.5°, p = 0.005). There were no significant differences between groups in terms of pre- and postoperative mean ODI and VAS scores at the 1-year follow-up. However, patients in the MIS group had much lower estimated blood loss and transfusion rates compared with patients in the hybrid or open groups (p < 0.001). Operating room time was significantly longer with the hybrid group compared with the MIS and open groups (p < 0.001). Major complications occurred in 14% of patients in the MIS group, 14% in the hybrid group, and 45% in the open group (p = 0.032).

    Conclusions

    This study provides valuable baseline characteristics of radiographic parameters among 3 different surgical techniques used in the treatment of adult spinal deformity. Each technique has advantages, but much like any surgical technique, the positive and negative elements must be considered when tailoring a treatment to a patient. Minimally invasive surgical techniques can result in clinical outcomes at 1 year comparable to those obtained from hybrid and open surgical techniques.
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    ItemOpen Access
    Comparison of two minimally invasive surgery strategies to treat adult spinal deformity.
    (Journal of neurosurgery. Spine, 2015-04) Park, Paul; Wang, Michael Y; Lafage, Virginie; Nguyen, Stacie; Ziewacz, John; Okonkwo, David O; Uribe, Juan S; Eastlack, Robert K; Anand, Neel; Haque, Raqeeb; Fessler, Richard G; Kanter, Adam S; Deviren, Vedat; La Marca, Frank; Smith, Justin S; Shaffrey, Christopher I; Mundis, Gregory M; Mummaneni, Praveen V; International Spine Study Group

    Object

    Minimally invasive surgery (MIS) techniques are becoming a more common means of treating adult spinal deformity (ASD). The aim of this study was to compare the hybrid (HYB) surgical approach, involving minimally invasive lateral interbody fusion with open posterior instrumented fusion, to the circumferential MIS (cMIS) approach to treat ASD.

    Methods

    The authors performed a retrospective, multicenter study utilizing data collected in 105 patients with ASD who were treated via MIS techniques. Criteria for inclusion were age older than 45 years, coronal Cobb angle greater than 20°, and a minimum of 1 year of follow-up. Patients were stratified into 2 groups: HYB (n = 62) and cMIS (n = 43).

    Results

    The mean age was 60.7 years in the HYB group and 61.0 years in the cMIS group (p = 0.910). A mean of 3.6 interbody fusions were performed in the HYB group compared with a mean of 4.0 interbody fusions in the cMIS group (p = 0.086). Posterior fusion involved a mean of 6.9 levels in the HYB group and a mean of 5.1 levels in the cMIS group (p = 0.003). The mean follow-up was 31.3 months for the HYB group and 38.3 months for the cMIS group. The mean Oswestry Disability Index (ODI) score improved by 30.6 and 25.7, and the mean visual analog scale (VAS) scores for back/leg pain improved by 2.4/2.5 and 3.8/4.2 for the HYB and cMIS groups, respectively. There was no significant difference between groups with regard to ODI or VAS scores. For the HYB group, the lumbar coronal Cobb angle decreased by 13.5°, lumbar lordosis (LL) increased by 8.2°, sagittal vertical axis (SVA) decreased by 2.2 mm, and LL-pelvic incidence (LL-PI) mismatch decreased by 8.6°. For the cMIS group, the lumbar coronal Cobb angle decreased by 10.3°, LL improved by 3.0°, SVA increased by 2.1 mm, and LL-PI decreased by 2.2°. There were no significant differences in these radiographic parameters between groups. The complication rate, however, was higher in the HYB group (55%) than in the cMIS group (33%) (p = 0.024).

    Conclusions

    Both HYB and cMIS approaches resulted in clinical improvement, as evidenced by decreased ODI and VAS pain scores. While there was no significant difference in degree of radiographic correction between groups, the HYB group had greater absolute improvement in degree of lumbar coronal Cobb angle correction, increased LL, decreased SVA, and decreased LL-PI. The complication rate, however, was higher with the HYB approach than with the cMIS approach.
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    ItemOpen Access
    Complications in adult spinal deformity surgery: an analysis of minimally invasive, hybrid, and open surgical techniques.
    (Neurosurgical focus, 2014-05) Uribe, Juan S; Deukmedjian, Armen R; Mummaneni, Praveen V; Fu, Kai-Ming G; Mundis, Gregory M; Okonkwo, David O; Kanter, Adam S; Eastlack, Robert; Wang, Michael Y; Anand, Neel; Fessler, Richard G; La Marca, Frank; Park, Paul; Lafage, Virginie; Deviren, Vedat; Bess, Shay; Shaffrey, Christopher I; International Spine Study Group

    Object

    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.

    Methods

    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.

    Results

    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.

    Conclusions

    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.
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    ItemOpen Access
    Correlation of return to work with patient satisfaction after surgery for lumbar spondylolisthesis: an analysis of the Quality Outcomes Database.
    (Neurosurgical focus, 2020-05) DiGiorgio, Anthony M; Mummaneni, Praveen V; Park, Paul; Chan, Andrew K; Bisson, Erica F; Bydon, Mohamad; Foley, Kevin T; Glassman, Steven D; Shaffrey, Christopher I; Potts, Eric A; Shaffrey, Mark E; Coric, Domagoj; Knightly, John J; Wang, Michael Y; Fu, Kai-Ming; Asher, Anthony L; Virk, Michael S; Kerezoudis, Panagiotis; Alvi, Mohammed Ali; Guan, Jian; Haid, Regis W; Slotkin, Jonathan R

    Objective

    Return to work (RTW) and satisfaction are important outcome measures after surgery for degenerative spine disease. The authors queried the prospective Quality Outcomes Database (QOD) to determine if RTW correlated with patient satisfaction.

    Methods

    The QOD was queried for patients undergoing surgery for degenerative lumbar spondylolisthesis. The primary outcome of interest was correlation between RTW and patient satisfaction, as measured by the North American Spine Society patient satisfaction index (NASS). Secondarily, data on satisfied patients were analyzed to see what patient factors correlated with RTW.

    Results

    Of 608 total patients in the QOD spondylolisthesis data set, there were 292 patients for whom data were available on both satisfaction and RTW status. Of these, 249 (85.3%) were satisfied with surgery (NASS score 1-2), and 224 (76.7%) did RTW after surgery. Of the 68 patients who did not RTW after surgery, 49 (72.1%) were still satisfied with surgery. Of the 224 patients who did RTW, 24 (10.7%) were unsatisfied with surgery (NASS score 3-4). There were significantly more people who had an NASS score of 1 in the RTW group than in the non-RTW group (71.4% vs 42.6%, p < 0.05). Failure to RTW was associated with lower level of education, worse baseline back pain (measured with a numeric rating scale), and worse baseline disability (measured with the Oswestry Disability Index [ODI]).

    Conclusions

    There are a substantial number of patients who are satisfied with surgery even though they did not RTW. Patients who were satisfied with surgery and did not RTW typically had worse preoperative back pain and ODI and typically did not have a college education. While RTW remains an important measure after surgery, physicians should be mindful that patients who do not RTW may still be satisfied with their outcome.
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    ItemOpen Access
    Correlation of the Modified Japanese Orthopedic Association With Functional and Quality-of-Life Outcomes After Surgery for Degenerative Cervical Myelopathy: A Quality Outcomes Database Study.
    (Neurosurgery, 2022-12) Yee, Timothy J; Upadhyaya, Cheerag; Coric, Domagoj; Potts, Eric A; Bisson, Erica F; Turner, Jay; Knightly, Jack J; Fu, Kai-Ming; Foley, Kevin T; Tumialan, Luis; Shaffrey, Mark E; Bydon, Mohamad; Mummaneni, Praveen; Chou, Dean; Chan, Andrew; Meyer, Scott; Asher, Anthony L; Shaffrey, Christopher; Gottfried, Oren N; Than, Khoi D; Wang, Michael Y; Buchholz, Avery L; Haid, Regis; Park, Paul; Park, Paul

    Background

    The modified Japanese Orthopedic Association (mJOA) score is a widely used and validated metric for assessing severity of myelopathy. Its relationship to functional and quality-of-life outcomes after surgery has not been fully described.

    Objective

    To quantify the association of the mJOA with the Neck Disability Index (NDI) and EuroQol-5 Dimension (EQ-5D) after surgery for degenerative cervical myelopathy.

    Methods

    The cervical module of the prospectively enrolled Quality Outcomes Database was queried retrospectively for adult patients who underwent single-stage degenerative cervical myelopathy surgery. The mJOA score, NDI, and EQ-5D were assessed preoperatively and 3 and 12 months postoperatively. Improvement in mJOA was used as the independent variable in univariate and multivariable linear and logistic regression models.

    Results

    Across 14 centers, 1121 patients were identified, mean age 60.6 ± 11.8 years, and 52.5% male. Anterior-only operations were performed in 772 patients (68.9%). By univariate linear regression, improvements in mJOA were associated with improvements in NDI and EQ-5D at 3 and 12 months postoperatively (all P < .0001) and with improvements in the 10 NDI items individually. These findings were similar in multivariable regression incorporating potential confounders. The Pearson correlation coefficients for changes in mJOA with changes in NDI were -0.31 and -0.38 at 3 and 12 months postoperatively. The Pearson correlation coefficients for changes in mJOA with changes in EQ-5D were 0.29 and 0.34 at 3 and 12 months.

    Conclusion

    Improvements in mJOA correlated weakly with improvements in NDI and EQ-5D, suggesting that changes in mJOA may not be a suitable proxy for functional and quality-of-life outcomes.
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    ItemOpen Access
    Cost-effectiveness of posterior lumbar interbody fusion and/or transforaminal lumbar interbody fusion for grade 1 lumbar spondylolisthesis: a 5-year Quality Outcomes Database study.
    (Journal of neurosurgery. Spine, 2024-08) Yee, Timothy J; Liles, Campbell; Johnson, Sarah E; Ambati, Vardhaan S; DiGiorgio, Anthony M; Alan, Nima; Coric, Domagoj; Potts, Eric A; Bisson, Erica F; Knightly, John J; Fu, Kai-Ming G; Foley, Kevin T; Shaffrey, Mark E; Bydon, Mohamad; Chou, Dean; Chan, Andrew K; Meyer, Scott; Asher, Anthony L; Shaffrey, Christopher I; Slotkin, Jonathan R; Wang, Michael Y; Haid, Regis W; Glassman, Steven D; Virk, Michael S; Mummaneni, Praveen V; Park, Paul

    Objective

    Posterior lumbar interbody fusion (PLIF) and/or transforaminal lumbar interbody fusion (TLIF), referred to as "PLIF/TLIF," is a commonly performed operation for lumbar spondylolisthesis. Its long-term cost-effectiveness has not been well described. The aim of this study was to determine the 5-year cost-effectiveness of PLIF/TLIF for grade 1 degenerative lumbar spondylolisthesis using prospective data collected from the multicenter Quality Outcomes Database (QOD).

    Methods

    Patients enrolled in the prospective, multicenter QOD grade 1 lumbar spondylolisthesis module were included if they underwent single-stage PLIF/TLIF. EQ-5D scores at baseline, 3 months, 12 months, 24 months, 36 months, and 60 months were used to calculate gains in quality-adjusted life years (QALYs) associated with surgery relative to preoperative baseline. Healthcare-related costs associated with the index surgery and related reoperations were calculated using Medicare reimbursement-based cost estimates and validated using price transparency diagnosis-related group (DRG) charges and Medicare charge-to-cost ratios (CCRs). Cost per QALY gained over 60 months postoperatively was assessed.

    Results

    Across 12 surgical centers, 385 patients were identified. The mean patient age was 60.2 (95% CI 59.1-61.3) years, and 38% of patients were male. The reoperation rate was 5.7%. DRG 460 cost estimates were stable between our Medicare reimbursement-based models and the CCR-based model, validating the focus on Medicare reimbursement. Across the entire cohort, the mean QALY gain at 60 months postoperatively was 1.07 (95% CI 0.97-1.18), and the mean cost of PLIF/TLIF was $31,634. PLIF/TLIF was associated with a mean 60-month cost per QALY gained of $29,511. Among patients who did not undergo reoperation (n = 363), the mean 60-month QALY gain was 1.10 (95% CI 0.99-1.20), and cost per QALY gained was $27,591. Among those who underwent reoperation (n = 22), the mean 60-month QALY gain was 0.68 (95% CI 0.21-1.15), and the cost per QALY gained was $80,580.

    Conclusions

    PLIF/TLIF for degenerative grade 1 lumbar spondylolisthesis was associated with a mean 60-month cost per QALY gained of $29,511 with Medicare fees. This is far below the well-established societal willingness-to-pay threshold of $100,000, suggesting long-term cost-effectiveness. PLIF/TLIF remains cost-effective for patients who undergo reoperation.
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    ItemOpen Access
    Developing nonlinear k-nearest neighbors classification algorithms to identify patients at high risk of increased length of hospital stay following spine surgery.
    (Neurosurgical focus, 2023-06) Shahrestani, Shane; Chan, Andrew K; Bisson, Erica F; Bydon, Mohamad; Glassman, Steven D; Foley, Kevin T; Shaffrey, Christopher I; Potts, Eric A; Shaffrey, Mark E; Coric, Domagoj; Knightly, John J; Park, Paul; Wang, Michael Y; Fu, Kai-Ming; Slotkin, Jonathan R; Asher, Anthony L; Virk, Michael S; Michalopoulos, Giorgos D; Guan, Jian; Haid, Regis W; Agarwal, Nitin; Chou, Dean; Mummaneni, Praveen V

    Objective

    Spondylolisthesis is a common operative disease in the United States, but robust predictive models for patient outcomes remain limited. The development of models that accurately predict postoperative outcomes would be useful to help identify patients at risk of complicated postoperative courses and determine appropriate healthcare and resource utilization for patients. As such, the purpose of this study was to develop k-nearest neighbors (KNN) classification algorithms to identify patients at increased risk for extended hospital length of stay (LOS) following neurosurgical intervention for spondylolisthesis.

    Methods

    The Quality Outcomes Database (QOD) spondylolisthesis data set was queried for patients receiving either decompression alone or decompression plus fusion for degenerative spondylolisthesis. Preoperative and perioperative variables were queried, and Mann-Whitney U-tests were performed to identify which variables would be included in the machine learning models. Two KNN models were implemented (k = 25) with a standard training set of 60%, validation set of 20%, and testing set of 20%, one with arthrodesis status (model 1) and the other without (model 2). Feature scaling was implemented during the preprocessing stage to standardize the independent features.

    Results

    Of 608 enrolled patients, 544 met prespecified inclusion criteria. The mean age of all patients was 61.9 ± 12.1 years (± SD), and 309 (56.8%) patients were female. The model 1 KNN had an overall accuracy of 98.1%, sensitivity of 100%, specificity of 84.6%, positive predictive value (PPV) of 97.9%, and negative predictive value (NPV) of 100%. Additionally, a receiver operating characteristic (ROC) curve was plotted for model 1, showing an overall area under the curve (AUC) of 0.998. Model 2 had an overall accuracy of 99.1%, sensitivity of 100%, specificity of 92.3%, PPV of 99.0%, and NPV of 100%, with the same ROC AUC of 0.998.

    Conclusions

    Overall, these findings demonstrate that nonlinear KNN machine learning models have incredibly high predictive value for LOS. Important predictor variables include diabetes, osteoporosis, socioeconomic quartile, duration of surgery, estimated blood loss during surgery, patient educational status, American Society of Anesthesiologists grade, BMI, insurance status, smoking status, sex, and age. These models may be considered for external validation by spine surgeons to aid in patient selection and management, resource utilization, and preoperative surgical planning.