Browsing by Author "Nguyen, James H"

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    ItemOpen Access
    A Novel Junctional Tether Weave Technique for Adult Spinal Deformity: 2-Dimensional Operative Video.
    (Operative neurosurgery (Hagerstown, Md.), 2019-02) Buell, Thomas J; Mullin, Jeffrey P; Nguyen, James H; Taylor, Davis G; Garces, Juanita; Mazur, Marcus D; Buchholz, Avery L; Shaffrey, Mark E; Yen, Chun-Po; Shaffrey, Christopher I; Smith, Justin S
    Proximal junctional kyphosis (PJK) is a common problem after multilevel spine instrumentation for adult spinal deformity. Various anti-PJK techniques such as junctional tethers for ligamentous augmentation have been proposed. We present an operative video demonstrating technical nuances of junctional tether "weave" application. A 70-yr-old male with prior L2-S1 instrumented fusion presented with worsening back pain and posture. Imaging demonstrated pathological loss of lumbar lordosis (flat back deformity), proximal junctional failure, and pseudarthrosis. The patient had severe global and segmental sagittal malalignment, with sagittal vertical axis (SVA, C7-plumbline) measuring 22.3 cm, pelvic incidence (PI) 55°, lumbar lordosis (LL) 8° in kyphosis, pelvic tilt (PT) 30°, and thoracic kyphosis (TK) 6°. The patient gave informed consent for surgery and use of imaging for medical publication. Briefly, surgery first involved re-instrumentation with bilateral pedicle screws from T10 to S1. After right-sided iliac screw fixation (left-sided iliac screw fixation was not performed due to extensive prior iliac crest bone graft harvesting), we then completed a L2-3 Smith-Petersen osteotomy, extended L4 pedicle subtraction osteotomy, and L3-4 interbody arthrodesis with a 12° lordotic cage (9 × 14 × 40 mm). Cobalt Chromium rods were placed spanning the instrumentation bilaterally, and accessory supplemental rods spanning the PSO were attached. An anti-PJK junctional tether "weave" was then implemented using 4.5 mm polyethylene tape (Mersilene tape [Ethicon, Somerville, New Jersey]). Postoperative imaging demonstrated improved alignment (SVA 2.8 cm, PI 55°, LL 53°, PT 25°, TK 45°) and no significant neurological complications occurred during convalescence or at 6 mo postop.
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    ItemOpen Access
    Alignment Risk Factors for Proximal Junctional Kyphosis and the Effect of Lower Thoracic Junctional Tethers for Adult Spinal Deformity.
    (World neurosurgery, 2019-01) Buell, Thomas J; Chen, Ching-Jen; Quinn, John C; Buchholz, Avery L; Mazur, Marcus D; Mullin, Jeffrey P; Nguyen, James H; Taylor, Davis G; Bess, Shay; Line, Breton G; Ames, Christopher P; Schwab, Frank J; Lafage, Virginie; Shaffrey, Christopher I; Smith, Justin S

    Objective

    The aims of this retrospective cohort study were to 1) identify new alignment risk factors for proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) patients with lower thoracic upper instrumented vertebra (UIV) and 2) determine the effect of junctional tethers on PJK and UIV alignment.

    Methods

    We analyzed consecutive ASD patients who underwent posterior instrumented fusion with lower thoracic UIV (T9-T11). Posteriorly anchored junctional tethers were used more recently for ligamentous augmentation to prevent PJK. In addition to regional and global parameters, upper segmental lumbar lordosis (ULL) versus lower segmental lumbar lordosis and UIV angle (measured from UIV inferior endplate to horizontal) were assessed. Primary outcome of PJK was defined as proximal junctional angle >10° and >10° greater than the corresponding preoperative measurement. Univariable and multivariable analyses were performed.

    Results

    The study cohort comprised 120 ASD patients (mean age, 67 years) with minimum 1-year follow-up. Preoperative ULL (P = 0.034) and UIV angle (P = 0.026) were associated with PJK. No independent preoperative alignment risk factors of PJK were identified in multivariable analysis. Tether use was protective against PJK (odds ratio, 0.063 [0.016-0.247]; P < 0.001). PJK in tethered patients was more common with greater postoperative ULL (P = 0.047) and UIV angle (P = 0.026).

    Conclusions

    Junctional tethers significantly reduced PJK in ASD patients with lower thoracic UIV. In tethered patients, PJK was more common with greater postoperative lordosis of the upper lumbar spine and greater UIV angle. This finding suggests potential benefit of tethers to mitigate effects of segmental lumbar and focal UIV malalignment that may occur after deformity surgery.
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    ItemOpen Access
    Coronal Correction Using Kickstand Rods for Adult Thoracolumbar/Lumbar Scoliosis: Case Series With Analysis of Early Outcomes and Complications.
    (Operative neurosurgery (Hagerstown, Md.), 2020-09) Buell, Thomas J; Christiansen, Peter A; Nguyen, James H; Chen, Ching-Jen; Yen, Chun-Po; Shaffrey, Christopher I; Smith, Justin S

    Background

    The "kickstand rod technique" has been recently described for achieving and maintaining coronal correction in adult spinal deformity (ASD). Kickstand rods span scoliotic lumbar spine from the thoracolumbar junction proximally to a "kickstand iliac screw" distally. Using the iliac wing as a base, kickstand distraction produces powerful corrective forces. Limited literature exists for this technique, and its associated outcomes and complications are unknown.

    Objective

    To assess alignment changes, early outcomes, and complications associated with kickstand rod distraction for ASD.

    Methods

    Consecutive ASD patients treated with kickstand distraction at our institution were retrospectively analyzed.

    Results

    The cohort comprised 19 patients (mean age: 67 yr; 79% women; 63% prior fusion) with mean follow-up 21 wk (range: 2-72 wk). All patients had posterior-only approach surgery with tri-iliac fixation (third iliac screw for the kickstand) for mean fusion length 12 levels. Three-column osteotomy and lumbar transforaminal lumbar interbody fusion were performed in 5 (26%) and 15 (79%) patients, respectively. Postoperative alignment improved significantly (coronal balance: 8 to 1 cm [P < .001]; major curve: 37° to 12° [P < .001]; fractional curve: 20° to 10° [P < .001]; sagittal balance: 11 to 4 cm [P < .001]; pelvic incidence to lumbar lordosis mismatch: 38° to 9° [P < .001]). Pain Numerical Rating Scale scores improved significantly (back: 7.2 to 4.2 [P = .001]; leg: 5.9 to 1.7 [P = .001]). No instrumentation complications occurred. Motor weakness persisted in 1 patient. There were 3 reoperations (1-PJK, 1-wound dehiscence, and 1-overcorrection).

    Conclusion

    Among 19 ASD patients treated with kickstand rod distraction, alignment, and back/leg pain improved significantly following surgery. Complication rates were reasonable.
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    ItemOpen Access
    Low rates of complications after spinopelvic fixation with iliac screws in 260 adult patients with a minimum 2-year follow-up
    (Journal of Neurosurgery: Spine, 2019-05-01) Nguyen, James H; Buell, Thomas J; Wang, Tony R; Mullin, Jeffrey P; Mazur, Marcus D; Garces, Juanita; Taylor, Davis G; Yen, Chun-Po; Shaffrey, Christopher I; Smith, Justin S
    OBJECTIVE Recent literature describing complications associated with spinopelvic fixation with iliac screws in adult patients has been limited but has suggested high complication rates. The authors’ objective was to report their experience with iliac screw fixation in a large series of patients with a 2-year minimum follow-up. METHODS Of 327 adult patients undergoing spinopelvic fixation with iliac screws at the authors’ institution between 2010 and 2015, 260 met the study inclusion criteria (age ≥ 18 years, first-time iliac screw placement, and 2-year minimum follow-up). Patients with active spinal infection were excluded. All iliac screws were placed via a posterior midline approach using fluoroscopic guidance. Iliac screw heads were deeply recessed into the posterior superior iliac spine. Clinical and radiographic data were obtained and analyzed. RESULTS Twenty patients (7.7%) had iliac screw–related complication, which included fracture (12, 4.6%) and/or screw loosening (9, 3.5%). No patients had iliac screw head prominence that required revision surgery or resulted in pain, wound dehiscence, or poor cosmesis. Eleven patients (4.2%) had rod or connector fracture below S1. Overall, 23 patients (8.8%) had L5–S1 pseudarthrosis. Four patients (1.5%) had fracture of the S1 screw. Seven patients (2.7%) had wound dehiscence (unrelated to the iliac screw head) or infection. The rate of reoperation (excluding proximal junctional kyphosis) was 17.7%. On univariate analysis, an iliac screw–related complication rate was significantly associated with revision fusion (70.0% vs 41.2%, p = 0.013), a greater number of instrumented vertebrae (mean 12.6 vs 10.3, p = 0.014), and greater postoperative pelvic tilt (mean 27.7° vs 23.2°, p = 0.04). Lumbosacral junction–related complications were associated with a greater mean number of instrumented vertebrae (12.6 vs 10.3, p = 0.014). Reoperation was associated with a younger mean age at surgery (61.8 vs 65.8 years, p = 0.014), a greater mean number of instrumented vertebrae (12.2 vs 10.2, p = 0.001), and longer clinical and radiological mean follow-up duration (55.8 vs 44.5 months, p < 0.001; 55.8 vs 44.6 months, p < 0.001, respectively). On multivariate analysis, reoperation was associated with longer clinical follow-up (p < 0.001). CONCLUSIONS Previous studies on iliac screw fixation have reported very high rates of complications and reoperation (as high as 53.6%). In this large, single-center series of adult patients, iliac screws were an effective method of spinopelvic fixation that had high rates of lumbosacral fusion and far lower complication rates than previously reported. Collectively, these findings argue that iliac screw fixation should remain a favored technique for spinopelvic fixation.
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    Postoperative pyoderma gangrenosum after spinal fusion with instrumentation: case report.
    (Journal of neurosurgery. Spine, 2019-10) Snyder, M Harrison; Ampie, Leonel; Forrester, Vernon J; Wilson, JoAnne C; Nguyen, James H; Shaffrey, Christopher I; Buchholz, Avery L
    Pyoderma gangrenosum (PG) is a rare inflammatory dermatosis that is most often associated with inflammatory bowel disease, but which can occur as a pathergic reaction around surgical incisions. The authors report the case of a patient who developed postoperative PG over the course of several months after undergoing extensive spinal instrumentation between the T4 and iliac levels. This is only the second such case occurring after spine surgery to be reported. The authors additionally review the literature to characterize treatment approaches and outcomes for this condition. The case highlights a potentially severe adverse effect of surgery that can be difficult to recognize and causes delays in effective treatment. It also demonstrates the importance of multidisciplinary collaboration in the effective care of patients.
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    Radiographic outcome and complications after single-level lumbar extended pedicle subtraction osteotomy for fixed sagittal malalignment: a retrospective analysis of 55 adult spinal deformity patients with a minimum 2-year follow-up.
    (Journal of neurosurgery. Spine, 2018-11) Buell, Thomas J; Nguyen, James H; Mazur, Marcus D; Mullin, Jeffrey P; Garces, Juanita; Taylor, Davis G; Yen, Chun-Po; Shaffrey, Mark E; Shaffrey, Christopher I; Smith, Justin S
    OBJECTIVEFixed sagittal spinal malalignment is a common problem in adult spinal deformity (ASD). Various three-column osteotomy techniques, including the extended pedicle subtraction osteotomy (ePSO), may correct global and regional malalignment in this patient population. In contrast to the number of reports on traditional PSO (Schwab grade 3 osteotomy), there is limited literature on the outcomes of ePSO (Schwab grade 4 osteotomy) in ASD surgery. The objective of this retrospective study was to provide focused investigation of radiographic outcomes and complications of single-level lumbar ePSO for ASD patients with fixed sagittal malalignment.METHODSConsecutive ASD patients in whom sagittal malalignment had been treated with single-level lumbar ePSO at the authors' institution between 2010 and 2015 were analyzed, and those with a minimum 2-year follow-up were included in the study. Radiographic analyses included assessments of segmental lordosis through the ePSO site (sagittal Cobb angle measured from the superior endplate of the vertebra above and inferior endplate of the vertebra below the ePSO), lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence and LL mismatch, thoracic kyphosis (TK), and sagittal vertical axis (SVA) on standing long-cassette radiographs. Complications were analyzed for the entire group.RESULTSAmong 71 potentially eligible patients, 55 (77%) had a minimum 2-year follow-up and were included in the study. Overall, the average postoperative increases in ePSO segmental lordosis and overall LL were 41° ± 14° (range 7°-69°, p < 0.001) and 38° ± 11° (range 9°-58°, p < 0.001), respectively. The average SVA improvement was 13 ± 7 cm (range of correction: -33.6 to 3.4 cm, p < 0.001). These measurements were maintained when comparing early postoperative to last follow-up values, respectively (mean follow-up 52 months, range 26-97 months): ePSO segmental lordosis, 34° vs 33°, p = 0.270; LL, 47.3° vs 46.7°, p = 0.339; and SVA, 4 vs 5 cm, p = 0.330. Rod fracture (RF) at the ePSO site occurred in 18.2% (10/55) of patients, and pseudarthrosis (PA) at the ePSO site was confirmed by CT imaging or during rod revision surgery in 14.5% (8/55) of patients. Accessory supplemental rods across the ePSO site, a more recently employed technique, significantly reduced the occurrence of RF or PA on univariate (p = 0.004) and multivariable (OR 0.062, 95% CI 0.007-0.553, p = 0.013) analyses; this effect approached statistical significance on Kaplan-Meier analysis (p = 0.053, log-rank test). Interbody cage placement at the ePSO site resulted in greater ePSO segmental lordosis correction (45° vs 35°, p = 0.007) without significant change in RF or PA (p = 0.304). Transient and persistent motor deficits occurred in 14.5% (8/55) and 1.8% (1/55) of patients, respectively.CONCLUSIONSExtended PSO is an effective technique to correct fixed sagittal malalignment for ASD. In comparison to traditional PSO techniques, ePSO may allow greater focal correction with comparable complication rates, especially with interbody cage placement at the ePSO site and the use of accessory supplemental rods.
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    Surgical correction of severe adult lumbar scoliosis (major curves ≥ 75°): retrospective analysis with minimum 2-year follow-up.
    (Journal of neurosurgery. Spine, 2019-06-21) Buell, Thomas J; Chen, Ching-Jen; Nguyen, James H; Christiansen, Peter A; Murthy, Saikiran G; Buchholz, Avery L; Yen, Chun-Po; Shaffrey, Mark E; Shaffrey, Christopher I; Smith, Justin S
    OBJECTIVE:Prior reports have demonstrated the efficacy of surgical correction for adult lumbar scoliosis. Many of these reports focused on mild to moderate scoliosis. The authors' objective was to report their experience and to assess outcomes and complications after deformity correction for severe adult scoliosis. METHODS:The authors retrospectively analyzed consecutive adult scoliosis patients with major thoracolumbar/lumbar (TL/L) curves ≥ 75° who underwent deformity correction at their institution. Those eligible with a minimum 2 years of follow-up were included. Demographic, surgical, coronal and sagittal plane radiographic measurements, and health-related quality of life (HRQL) scores were analyzed. RESULTS:Among 26 potentially eligible patients, 22 (85%) had a minimum 2 years of follow-up (range 24-89 months) and were included in the study (mean age 57 ± 11 years; 91% women). The cohort comprised 16 (73%), 4 (18%), and 2 (9%) patients with adult idiopathic scoliosis, de novo degenerative scoliosis, and iatrogenic scoliosis, respectively. The surgical approach was posterior-only and multistage anterior-posterior in 18 (82%) and 4 (18%) patients, respectively. Three-column osteotomy was performed in 5 (23%) patients. Transforaminal and anterior lumbar interbody fusion were performed in 14 (64%) and 4 (18%) patients, respectively. All patients had sacropelvic fixation with uppermost instrumented vertebra in the lower thoracic spine (46% [10/22]) versus upper thoracic spine (55% [12/22]). The mean fusion length was 14 ± 3 levels. Preoperative major TL/L and lumbosacral fractional (L4-S1) curves were corrected from 83° ± 8° to 28° ± 13° (p < 0.001) and 34° ± 8° to 13° ± 6° (p < 0.001), respectively. Global coronal and sagittal balance significantly improved from 5 ± 4 cm to 1 ± 1 cm (p = 0.001) and 9 ± 8 cm to 2 ± 3 cm (p < 0.001), respectively. Pelvic tilt significantly improved from 33° ± 9° to 23° ± 10° (p < 0.001). Significant improvement in HRQL measures included the following: Scoliosis Research Society (SRS) pain score (p = 0.009), SRS appearance score (p = 0.004), and SF-12/SF-36 physical component summary (PCS) score (p = 0.026). Transient and persistent neurological deficits occurred in 8 (36%) and 2 (9%) patients, respectively. Rod fracture/pseudarthrosis occurred in 6 (27%) patients (supplemental rods were utilized more recently in 23%). Revisions were performed in 7 (32%) patients. CONCLUSIONS:In this single-center surgical series for severe adult scoliosis (major curves ≥ 75°), a posterior-only or multistage anterior-posterior approach provided major curve correction of 66% and significant improvements in global coronal and sagittal spinopelvic alignment. Significant improvements were also demonstrated in HRQL measures (SRS pain, SRS appearance, and SF-12/SF-36 PCS). Complications and revisions were comparable to those of other reports involving less severe scoliosis. The results of this study warrant future prospective multicenter studies to further delineate outcomes and complication risks for severe adult scoliosis correction.