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Paul Park, Kai-Ming Fu, Robert K. Eastlack, Stacie Tran, Gregory M. Mundis Jr., Juan S. Uribe, Michael Y. Wang, Khoi D. Than, David O. Okonkwo, Adam S. Kanter, Pierce D. Nunley, Neel Anand, Richard G. Fessler, Dean Chou, Mark E. Oppenlander, Praveen V. Mummaneni and the International Spine Study Group

OBJECTIVE

It is now well accepted that spinopelvic parameters are correlated with clinical outcomes in adult spinal deformity (ASD). The purpose of this study was to determine whether obtaining optimal spinopelvic alignment was absolutely necessary to achieve a minimum clinically important difference (MCID) or substantial clinical benefit (SCB).

METHODS

A multicenter retrospective review of patients who underwent less-invasive surgery for ASD was conducted. Inclusion criteria were age ≥ 18 years and one of the following: coronal Cobb angle > 20°, sagittal vertical axis (SVA) > 5 cm, pelvic tilt (PT) > 20°, or pelvic incidence to lumbar lordosis (PI-LL) mismatch > 10°. A total of 223 patients who were treated with circumferential minimally invasive surgery or hybrid surgery and had a minimum 2-year follow-up were identified. Based on optimal spinopelvic parameters (PI-LL mismatch ± 10° and SVA < 5 cm), patients were divided into aligned (AL) or malaligned (MAL) groups. The primary clinical outcome studied was the Oswestry Disability Index (ODI) score.

RESULTS

There were 74 patients in the AL group and 149 patients in the MAL group. Age and body mass index were similar between groups. Although the baseline SVA was similar, PI-LL mismatch (9.9° vs 17.7°, p = 0.002) and PT (19° vs 24.7°, p = 0.001) significantly differed between AL and MAL groups, respectively. As expected postoperatively, the AL and MAL groups differed significantly in PI-LL mismatch (−0.9° vs 13.1°, p < 0.001), PT (14° vs 25.5°, p = 0.001), and SVA (11.8 mm vs 48.3 mm, p < 0.001), respectively. Notably, there was no difference in the proportion of AL or MAL patients in whom an MCID (52.75% vs 61.1%, p > 0.05) or SCB (40.5% vs 46.3%, p > 0.05) was achieved for ODI score, respectively. Similarly, no differences in percentage of patients obtaining an MCID or SCB for visual analog scale back and leg pain score were observed. On multivariate analysis controlling for surgical and preoperative demographic differences, achieving optimal spinopelvic parameters was not associated with achieving an MCID (OR 0.645, 95% CI 0.31–1.33) or an SCB (OR 0.644, 95% CI 0.31–1.35) for ODI score.

CONCLUSIONS

Achieving optimal spinopelvic parameters was not a predictor for achieving an MCID or SCB. Since spinopelvic parameters are correlated with clinical outcomes, the authors’ findings suggest that the presently accepted optimal spinopelvic parameters may require modification. Other factors, such as improvement in neurological symptoms and/or segmental instability, also likely impacted the clinical outcomes.

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Dominic Amara, Praveen V. Mummaneni, Christopher P. Ames, Bobby Tay, Vedat Deviren, Shane Burch, Sigurd H. Berven and Dean Chou

OBJECTIVE

Many options exist for the surgical management of adult spinal deformity. Radiculopathy and lumbosacral pain from the fractional curve (FC), typically from L4 to S1, is frequently a reason for scoliosis patients to pursue surgical intervention. The purpose of this study was to evaluate the outcomes of limited fusion of the FC only versus treatment of the entire deformity with long fusions.

METHODS

All adult scoliosis patients treated at the authors’ institution in the period from 2006 to 2016 were retrospectively analyzed. Patients with FCs from L4 to S1 > 10° and radiculopathy ipsilateral to the concavity of the FC were eligible for study inclusion and had undergone three categories of surgery: 1) FC only (FC group), 2) lower thoracic to sacrum (LT group), or 3) upper thoracic to sacrum (UT group). Primary outcomes were the rates of revision surgery and complications. Secondary outcomes were estimated blood loss, length of hospital stay, and discharge destination. Spinopelvic parameters were measured, and patients were stratified accordingly.

RESULTS

Of the 99 patients eligible for inclusion in the study, 27 were in the FC group, 46 in the LT group, and 26 in the UT group. There were no significant preoperative differences in age, sex, smoking status, prior operation, FC magnitude, pelvic tilt (PT), sagittal vertical axis (SVA), coronal balance, pelvic incidence–lumbar lordosis (PI-LL) mismatch, or proportion of well-aligned spines (SVA < 5 cm, PI-LL mismatch < 10°, and PT < 20°) among the three treatment groups. Mean follow-up was 30 (range 12–112) months, with a minimum 1-year follow-up. The FC group had a lower medical complication rate (22% [FC] vs 57% [LT] vs 58% [UT], p = 0.009) but a higher rate of extension surgery (26% [FC] vs 13% [LT] vs 4% [UT], p = 0.068). The respective average estimated blood loss (592 vs 1950 vs 2634 ml, p < 0.001), length of hospital stay (5.5 vs 8.3 vs 8.3 days, p < 0.001), and rate of discharge to acute rehabilitation (30% vs 46% vs 85%, p < 0.001) were all lower for FC and highest for UT.

CONCLUSIONS

Treatment of the FC only is associated with a lower complication rate, shorter hospital stay, and less blood loss than complete scoliosis treatment. However, there is a higher associated rate of extension of the construct to the lower or upper thoracic levels, and patients should be counseled when considering their options.

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Paul Park, Kai-Ming Fu, Praveen V. Mummaneni, Juan S. Uribe, Michael Y. Wang, Stacie Tran, Adam S. Kanter, Pierce D. Nunley, David O. Okonkwo, Christopher I. Shaffrey, Gregory M. Mundis Jr., Dean Chou, Robert Eastlack, Neel Anand, Khoi D. Than, Joseph M. Zavatsky, Richard G. Fessler and the International Spine Study Group

OBJECTIVE

Achieving appropriate spinopelvic alignment in deformity surgery has been correlated with improvement in pain and disability. Minimally invasive surgery (MIS) techniques have been used to treat adult spinal deformity (ASD); however, there is concern for inadequate sagittal plane correction. Because age can influence the degree of sagittal correction required, the purpose of this study was to analyze whether obtaining optimal spinopelvic alignment is required in the elderly to obtain clinical improvement.

METHODS

A multicenter database of ASD patients was queried. Inclusion criteria were age ≥ 18 years; an MIS component as part of the index procedure; at least one of the following: pelvic tilt (PT) > 20°, sagittal vertical axis (SVA) > 50 mm, pelvic incidence to lumbar lordosis (PI-LL) mismatch > 10°, or coronal curve > 20°; and minimum follow-up of 2 years. Patients were stratified into younger (< 65 years) and older (≥ 65 years) cohorts. Within each cohort, patients were categorized into aligned (AL) or mal-aligned (MAL) subgroups based on postoperative radiographic measurements. Mal-alignment was defined as a PI-LL > 10° or SVA > 50 mm. Pre- and postoperative radiographic and clinical outcomes were compared.

RESULTS

Of the 185 patients, 107 were in the younger cohort and 78 in the older cohort. Based on postoperative radiographs, 36 (33.6%) of the younger patients were in the AL subgroup and 71 (66.4%) were in the MAL subgroup. The older patients were divided into 2 subgroups based on alignment; there were 26 (33.3%) patients in the AL and 52 (66.7%) in the MAL subgroups. Overall, patients within both younger and older cohorts significantly improved with regard to postoperative visual analog scale (VAS) scores for back and leg pain and Oswestry Disability Index (ODI) scores. In the younger cohort, there were no significant differences in postoperative VAS back and leg pain scores between the AL and MAL subgroups. However, the postoperative ODI score of 37.9 in the MAL subgroup was significantly worse than the ODI score of 28.5 in the AL subgroup (p = 0.019). In the older cohort, there were no significant differences in postoperative VAS back and leg pain score or ODI between the AL and MAL subgroups.

CONCLUSIONS

MIS techniques did not achieve optimal spinopelvic alignment in most cases. However, age appears to impact the degree of sagittal correction required. In older patients, optimal spinopelvic alignment thresholds did not need to be achieved to obtain similar symptomatic improvement. Conversely, in younger patients stricter adherence to optimal spinopelvic alignment thresholds may be needed.

https://thejns.org/doi/abs/10.3171/2018.4.SPINE171153

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Junseok Bae, Alexander A. Theologis, Russell Strom, Bobby Tay, Shane Burch, Sigurd Berven, Praveen V. Mummaneni, Dean Chou, Christopher P. Ames and Vedat Deviren

OBJECTIVE

Surgical treatment of adult spinal deformity (ASD) is an effective endeavor that can be accomplished using a variety of surgical strategies. Here, the authors assess and compare radiographic data, complications, and health-related quality-of-life (HRQoL) outcome scores among patients with ASD who underwent a posterior spinal fixation (PSF)–only approach, a posterior approach combined with lateral lumbar interbody fusion (LLIF+PSF), or a posterior approach combined with anterior lumbar interbody fusion (ALIF+PSF).

METHODS

The medical records of consecutive adults who underwent thoracolumbar fusion for ASD between 2003 and 2013 at a single institution were reviewed. Included were patients who underwent instrumentation from the pelvis to L-1 or above, had a sagittal vertical axis (SVA) of < 10 cm, and underwent a minimum of 2 years’ follow-up. Those who underwent a 3-column osteotomy were excluded. Three groups of patients were compared on the basis of the procedure performed, LLIF+PSF, ALIF+PSF, and PSF only. Perioperative spinal deformity parameters, complications, and HRQoL outcome scores (Oswestry Disability Index [ODI], Scoliosis Research Society 22-question Questionnaire [SRS-22], 36-Item Short Form Health Survey [SF-36], visual analog scale [VAS] for back/leg pain) from each group were assessed and compared with each other using ANOVA. The minimal clinically important differences used were −1.2 (VAS back pain), −1.6 (VAS leg pain), −15 (ODI), 0.587/0.375/0.8/0.42 (SRS-22 pain/function/self-image/mental health), and 5.2 (SF-36, physical component summary).

RESULTS

A total of 221 patients (58 LLIF, 91 ALIF, 72 PSF only) met the inclusion criteria. Average deformities consisted of a SVA of < 10 cm, a pelvic incidence–lumbar lordosis (LL) mismatch of > 10°, a pelvic tilt of > 20°, a lumbar Cobb angle of > 20°, and a thoracic Cobb angle of > 15°. Preoperative SVA, LL, pelvic incidence–LL mismatch, and lumbar and thoracic Cobb angles were similar among the groups. Patients in the PSF-only group had more comorbidities, those in the ALIF+PSF group were, on average, younger and had a lower body mass index than those in the LLIF+PSF group, and patients in the LLIF+PSF group had a significantly higher mean number of interbody fusion levels than those in the ALIF+PSF and PSF-only groups. At final follow-up, all radiographic parameters and the mean numbers of complications were similar among the groups. Patients in the LLIF+PSF group had proximal junctional kyphosis that required revision surgery significantly less often and fewer proximal junctional fractures and vertebral slips. All preoperative HRQoL scores were similar among the groups. After surgery, the LLIF+PSF group had a significantly lower ODI score, higher SRS-22 self-image/total scores, and greater achievement of the minimal clinically important difference for the SRS-22 pain score.

CONCLUSIONS

Satisfactory radiographic outcomes can be achieved similarly and adequately with these 3 surgical approaches for patients with ASD with mild to moderate sagittal deformity. Compared with patients treated with an ALIF+PSF or PSF-only surgical strategy, patients who underwent LLIF+PSF had lower rates of proximal junctional kyphosis and mechanical failure at the upper instrumented vertebra and less back pain, less disability, and better SRS-22 scores.

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Khoi D. Than, Praveen V. Mummaneni, Kelly J. Bridges, Stacie Tran, Paul Park, Dean Chou, Frank La Marca, Juan S. Uribe, Todd D. Vogel, Pierce D. Nunley, Robert K. Eastlack, Neel Anand, David O. Okonkwo, Adam S. Kanter and Gregory M. Mundis Jr.

OBJECTIVE

High-quality studies that compare outcomes of open and minimally invasively placed pedicle screws for adult spinal deformity are needed. Therefore, the authors compared differences in complications from a circumferential minimally invasive spine (MIS) surgery and those from a hybrid surgery.

METHODS

A retrospective review of a multicenter database of patients with spinal deformity who were treated with an MIS surgery was performed. Database inclusion criteria included an age of ≥ 18 years and at least 1 of the following: a coronal Cobb angle of > 20°, a sagittal vertical axis of > 5 cm, a pelvic incidence–lumbar lordosis angle of > 10°, and/or a pelvic tilt of > 20°. Patients were propensity matched according to the levels instrumented.

RESULTS

In this database, a complete data set was available for 165 patients, and after those who underwent 3-column osteotomy were excluded, 137 patients were available for analysis; 76 patients remained after propensity matching (MIS surgery group 38 patients, hybrid surgery group 38 patients). The authors found no difference in demographics, number of levels instrumented, or preoperative and postoperative radiographic results. At least 1 complication was suffered by 55.3% of patients in the hybrid surgery group and 44.7% of those in the MIS surgery group (p = 0.359). Patients in the MIS surgery group had significantly fewer neurological, operative, and minor complications than those in the hybrid surgery group. The reoperation rates in both groups were similar. The most common complication category for the MIS surgery group was radiographic and for the hybrid surgery group was neurological. Patients in both groups experienced postoperative improvement in their Oswestry Disability Index and visual analog scale (VAS) back and leg pain scores (all p < 0.05); however, MIS surgery provided a greater reduction in leg pain according to VAS scores.

CONCLUSIONS

Overall complication rates in the MIS and hybrid surgery groups were similar. MIS surgery resulted in significantly fewer neurological, operative, and minor complications. Reoperation rates in the 2 groups were similar, and despite complications, the patients reported significant improvement in their pain and function.

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Pierce D. Nunley, Gregory M. Mundis Jr., Richard G. Fessler, Paul Park, Joseph M. Zavatsky, Juan S. Uribe, Robert K. Eastlack, Dean Chou, Michael Y. Wang, Neel Anand, Kelly A. Frank, Marcus B. Stone, Adam S. Kanter, Christopher I. Shaffrey, Praveen V. Mummaneni and the International Spine Study Group

OBJECTIVE

The aim of this study was to educate medical professionals about potential financial impacts of improper diagnosis-related group (DRG) coding in adult spinal deformity (ASD) surgery.

METHODS

Medicare’s Inpatient Prospective Payment System PC Pricer database was used to collect 2015 reimbursement data for ASD procedures from 12 hospitals. Case type, hospital type/location, number of operative levels, proper coding, length of stay, and complications/comorbidities (CCs) were analyzed for effects on reimbursement. DRGs were used to categorize cases into 3 types: 1) anterior or posterior only fusion, 2) anterior fusion with posterior percutaneous fixation with no dorsal fusion, and 3) combined anterior and posterior fixation and fusion.

RESULTS

Pooling institutions, cases were reimbursed the same for single-level and multilevel ASD surgery. Longer stay, from 3 to 8 days, resulted in an additional $1400 per stay. Posterior fusion was an additional $6588, while CCs increased reimbursement by approximately $13,000. Academic institutions received higher reimbursement than private institutions, i.e., approximately $14,000 (Case Types 1 and 2) and approximately $16,000 (Case Type 3). Urban institutions received higher reimbursement than suburban institutions, i.e., approximately $3000 (Case Types 1 and 2) and approximately $3500 (Case Type 3). Longer stay, from 3 to 8 days, increased reimbursement between $208 and $494 for private institutions and between $1397 and $1879 for academic institutions per stay.

CONCLUSIONS

Reimbursement is based on many factors not controlled by surgeons or hospitals, but proper DRG coding can significantly impact the financial health of hospitals and availability of quality patient care.

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Darryl Lau, Ethan A. Winkler, Khoi D. Than, Dean Chou and Praveen V. Mummaneni

OBJECTIVE

Cervical curvature is an important factor when deciding between laminoplasty and laminectomy with posterior spinal fusion (LPSF) for cervical spondylotic myelopathy (CSM). This study compares outcomes following laminoplasty and LPSF in patients with matched postoperative cervical lordosis.

METHODS

Adults undergoing laminoplasty or LPSF for cervical CSM from 2011 to 2014 were identified. Matched cohorts were obtained by excluding LPSF patients with postoperative cervical Cobb angles outside the range of laminoplasty patients. Clinical outcomes and radiographic results were compared. A subgroup analysis of patients with and without preoperative pain was performed, and the effects of cervical curvature on pain outcomes were examined.

RESULTS

A total of 145 patients were included: 101 who underwent laminoplasty and 44 who underwent LPSF. Preoperative Nurick scale score, pain incidence, and visual analog scale (VAS) neck pain scores were similar between the two groups. Patients who underwent LPSF had significantly less preoperative cervical lordosis (5.8° vs 10.9°, p = 0.018). Preoperative and postoperative C2–7 sagittal vertical axis (SVA) and T-1 slope were similar between the two groups. Laminoplasty cases were associated with less blood loss (196.6 vs 325.0 ml, p < 0.001) and trended toward shorter hospital stays (3.5 vs 4.3 days, p = 0.054). The perioperative complication rate was 8.3%; there was no significant difference between the groups. LPSF was associated with a higher long-term complication rate (11.6% vs 2.2%, p = 0.036), with pseudarthrosis accounting for 3 of 5 complications in the LPSF group. Follow-up cervical Cobb angle was similar between the groups (8.8° vs 7.1°, p = 0.454). At final follow-up, LPSF had a significantly lower mean Nurick score (0.9 vs 1.4, p = 0.014). Among patients with preoperative neck pain, pain incidence (36.4% vs 31.3%, p = 0.629) and VAS neck pain (2.1 vs 1.8, p = 0.731) were similar between the groups. Similarly, in patients without preoperative pain, there was no significant difference in pain incidence (19.4% vs 18.2%, p = 0.926) and VAS neck pain (1.0 vs 1.1, p = 0.908). For laminoplasty, there was a significant trend for lower pain incidence (p = 0.010) and VAS neck pain (p = 0.004) with greater cervical lordosis, especially when greater than 20° (p = 0.011 and p = 0.018). Mean follow-up was 17.3 months.

CONCLUSIONS

For patients with CSM, LPSF was associated with slightly greater blood loss and a higher long-term complication rate, but offered greater neurological improvement than laminoplasty. In cohorts of matched follow-up cervical sagittal alignment, pain outcomes were similar between laminoplasty and LPSF patients. However, among laminoplasty patients, greater cervical lordosis was associated with better pain outcomes, especially for lordosis greater than 20°. Cervical curvature (lordosis) should be considered as an important factor in pain outcomes following posterior decompression for multilevel CSM.

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Anthony M. DiGiorgio, Caleb S. Edwards, Michael S. Virk, Praveen V. Mummaneni and Dean Chou

The prepsoas retroperitoneal approach is a minimally invasive technique used for anterior lumbar interbody fusion. The approach may have a more favorable risk profile than the transpsoas approach, decreasing the risks that come with dissecting through the psoas muscle. However, the oblique angle of the spine in the prepsoas approach can be disorienting and challenging. This technical report provides an overview of the use of navigation in prepsoas oblique lateral lumbar interbody fusion in a series of 49 patients.

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Darryl Lau and Dean Chou

OBJECTIVE

During the mini-open posterior corpectomy, percutaneous instrumentation without fusion is performed above and below the corpectomy level. In this study, the authors' goal was to compare the perioperative and long-term implant failure rates of patients who underwent nonfused percutaneous instrumentation with those of patients who underwent traditional open instrumented fusion.

METHODS

Adult patients who underwent posterior thoracic corpectomies with cage reconstruction between 2009 and 2014 were identified. Patients who underwent mini-open corpectomy had percutaneous instrumentation without fusion, and patients who underwent open corpectomy had instrumented fusion above and below the corpectomy site. The authors compared perioperative outcomes and rates of implant failure requiring reoperation between the open (fused) and mini-open (unfused) groups.

RESULTS

A total of 75 patients were identified, and 53 patients (32 open and 21 mini-open) were available for followup. The mean patient age was 52.8 years, and 56.6% of patients were male. There were no significant differences in baseline variables between the 2 groups. The overall perioperative complication rate was 15.1%, and there was no significant difference between the open and mini-open groups (18.8% vs 9.5%; p = 0.359). The mean hospital stay was 10.5 days. The open group required a significantly longer stay than the mini-open group (12.8 vs 7.1 days; p < 0.001). Overall implant failure rates requiring reoperation were 1.9% at 6 months, 9.1% at 1 year, and 14.7% at 2 years. There were no significant differences in reoperation rates between the open and mini-open groups at 6 months (3.1% vs 0.0%, p = 0.413), 1 year (10.7% vs 6.2%, p = 0.620), and 2 years (18.2% vs 8.3%, p = 0.438). The overall mean follow-up was 29.2 months.

CONCLUSIONS

These findings suggest that percutaneous instrumentation without fusion in mini-open transpedicular corpectomies offers similar implant failure and reoperation rates as open instrumented fusion as far out as 2 years of follow-up.

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Ganesh M. Shankar, Michelle J. Clarke, Tamir Ailon, Laurence D. Rhines, Shreyaskumar R. Patel, Arjun Sahgal, Ilya Laufer, Dean Chou, Mark H. Bilsky, Daniel M. Sciubba, Michael G. Fehlings, Charles G. Fisher, Ziya L. Gokaslan and John H. Shin

OBJECTIVE

Primary osteosarcoma of the spine is a rare osseous neoplasm. While previously reported retrospective studies have demonstrated that overall patient survival is impacted mostly by en bloc resection and chemotherapy, the continued management of residual disease remains to be elucidated. This systematic review was designed to address the role of revision surgery and multimodal adjuvant therapy in cases in which en bloc excision is not initially achieved.

METHODS

A systematic literature search spanning the years 1966 to 2015 was performed on PubMed, Medline, EMBASE, and Web of Science to identify reports describing outcomes of patients who underwent biopsy alone, neurological decompression, or intralesional resection for osteosarcoma of the spine. Studies were reviewed qualitatively, and the clinical course of individual patients was aggregated for quantitative meta-analysis.

RESULTS

A total of 16 studies were identified for inclusion in the systematic review, of which 8 case reports were summarized qualitatively. These studies strongly support the role of chemotherapy for overall survival and moderately support adjuvant radiation therapy for local control. The meta-analysis revealed a statistically significant benefit in overall survival for performing revision tumor debulking (p = 0.01) and also for chemotherapy at relapse (p < 0.01). Adjuvant radiation therapy was associated with longer survival, although this did not reach statistical significance (p = 0.06).

CONCLUSIONS

While the initial therapeutic goal in the management of osteosarcoma of the spine is neoadjuvant chemotherapy followed by en bloc marginal resection, this objective is not always achievable given anatomical constraints and other limitations at the time of initial clinical presentation. This systematic review supports the continued aggressive use of revision surgery and multimodal adjuvant therapy when possible to improve outcomes in patients who initially undergo subtotal debulking of osteosarcoma. A limitation of this systematic review is that lesions amenable to subsequent resection or tumors inherently more sensitive to adjuvants would exaggerate a therapeutic effect of these interventions when studied in a retrospective fashion.