The authors report the case of a 70-year-old woman with lumbar spinal epidural arteriovenous fistula (SEDAVF) who experienced subarachnoid hemorrhage (SAH) after a diagnostic lumbar puncture. According to the literature, perimedullary spinal vein enlargement is a hallmark of spinal vascular diseases; however, there are certain cases in which routine sagittal MRI fails to disclose signal flow voids. In such cases, patients may undergo a lumbar tap to investigate the possible causes of spinal inflammatory or demyelinating disease. Recognizing this phenomenon is essential because lumbar puncture of the epidural venous pouch or an enlarged intradural vein in SEDAVF may induce severe SAH. A high clinical index of suspicion can prevent similar cases in lumbar SEDAVF.
Takumi Kajitani, Toshiki Endo, Tomoo Inoue, Kenichi Sato, Yasushi Matsumoto and Teiji Tominaga
Naoya Kikuchi, Masafumi Uesugi, Masao Koda, Tomoaki Shimizu, Kohei Murakami, Mamoru Kono, Haruka Tanaka and Masashi Yamazaki
The use of methotrexate (MTX) to treat rheumatoid arthritis (RA) is increasing. Recently, MTX-associated lymphoproliferative disorder (MTX-LPD) has been frequently reported as lymphoma occurring during MTX therapy. The authors report their experience with a relatively rare case of MTX-LPD presenting in the lumbar spine. The patient, a 73-year-old woman who experienced low-back pain while receiving MTX therapy for RA, was suspected of having developed MTX-LPD based on her medical history, images of the L1 vertebra, and transpedicular biopsy results. One week after discontinuing MTX, the patient’s low-back pain reportedly improved. The woman was diagnosed with MTX-LPD based on histopathological findings. MTX discontinuation alone coincided with spontaneous tumor regression. Because MTX-LPD can occur in tissues other than lymph nodes, such as in bones and joints, it is a disease that should be considered when diagnosing spinal tumors in patients receiving MTX therapy.
Mladen Djurasovic, Katlyn E. McGraw, Kelly Bratcher, Charles H. Crawford III, John R. Dimar II, Rolando M. Puno, Steven D. Glassman, R. Kirk Owens II and Leah Y. Carreon
The goal of this study was to determine efficacy and cost-effectiveness of Cell Saver in 2- and 3-level lumbar decompression and fusion.
Patients seen at a tertiary care spine center who were undergoing a posterior 2- or 3-level lumbar decompression and fusion were randomized to have Cell Saver used during their surgery (CS group, n = 48) or not used (No Cell Saver [NCS] group, n = 47). Data regarding preoperative and postoperative hemoglobin and hematocrit, estimated blood loss, volume of Cell Saver blood reinfused, number of units and volume of allogeneic blood transfused intraoperatively and postoperatively, complications, and costs were collected. Costs associated with Cell Saver use were calculated based on units of allogeneic blood transfusions averted.
Demographics and surgical parameters were similar in both groups. The mean estimated blood loss was similar in both groups: 612 ml in the CS group and 742 ml in the NCS group. There were 53 U of allogeneic blood transfused in 29 patients in the NCS group at a total blood product cost of $67,688; and 38 U of allogeneic blood transfused in 16 patients in the CS group at a total blood cost of $113,162, resulting in a cost of $3031 per allogeneic blood transfusion averted using Cell Saver.
Cell Saver use produced lower rates of allogeneic transfusion but was found to be more expensive than using only allogeneic blood for 2- and 3-level lumbar degenerative fusions. This increased cost may be reasonable to patients who perceive that the risks associated with allogeneic transfusions are unacceptable.
■ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: randomized controlled trial; evidence: class III.
Michael Akbar, Haidara Almansour, Renaud Lafage, Bassel G. Diebo, Bernd Wiedenhöfer, Frank Schwab, Virginie Lafage and Wojciech Pepke
The goal of this study was to investigate the impact of thoracic and lumbar alignment on cervical alignment in patients with adolescent idiopathic scoliosis (AIS).
Eighty-one patients with AIS who had a Cobb angle > 40° and full-length spine radiographs were included. Radiographs were analyzed using dedicated software to measure pelvic parameters (sacral slope [SS], pelvic incidence [PI], pelvic tilt [PT]); regional parameters (C1 slope, C0–C2 angle, chin-brow vertical angle [CBVA], slope of line of sight [SLS], McRae slope, McGregor slope [MGS], C2–7 [cervical lordosis; CL], C2–7 sagittal vertical axis [SVA], C2–T3, C2–T3 SVA, C2–T1 Harrison measurement [C2–T1 Ha], T1 slope, thoracic kyphosis [TK], lumbar lordosis [LL], and PI-LL mismatch); and global parameters (SVA). Patients were stratified by their lumbar alignment into hyperlordotic (LL > 59.7°) and normolordotic (LL 39.3° to 59.7°) groups and also, based on their thoracic alignment, into hypokyphotic (TK < −33.1°) and normokyphotic (TK −33.1° to −54.9°) groups. Finally, they were grouped based on their global alignment into either an anterior-aligned group or a posterior-aligned group.
The lumbar hyperlordotic group, in comparison to the normolordotic group, had a significantly larger LL, SS, PI (all p < 0.001), and TK (p = 0.014) and a significantly smaller PI-LL mismatch (p = 0.001). Lumbar lordosis had no influence on local cervical parameters.
The thoracic hypokyphotic group had a significantly larger PI-LL mismatch (p < 0.002) and smaller T1 slope (p < 0.001), and was significantly more posteriorly aligned than the normokyphotic group (−15.02 ± 8.04 vs 13.54 ± 6.17 [mean ± SEM], p = 0.006). The patients with hypokyphotic AIS had a kyphotic cervical spine (cervical kyphosis [CK]) (p < 0.001). Furthermore, a posterior-aligned cervical spine in terms of C2–7 SVA (p < 0.006) and C2–T3 SVA (p < 0.001) was observed in the thoracic hypokyphotic group.
Comparing patients in terms of global alignment, the posterior-aligned group had a significantly smaller T1 slope (p < 0.001), without any difference in terms of pelvic, lumbar, and thoracic parameters when compared to the anterior-aligned group. The posterior-aligned group also had a CK (−9.20 ± 1.91 vs 5.21 ± 2.95 [mean ± SEM], p < 0.001) and a more posterior-aligned cervical spine, as measured by C2–7 SVA (p = 0.003) and C2–T3 SVA (p < 0.001).
Alignment of the cervical spine is closely related to thoracic curvature and global alignment. In patients with AIS, a hypokyphotic thoracic alignment or posterior global alignment was associated with a global cervical kyphosis. Interestingly, upper cervical and cranial parameters were not statistically different in all investigated groups, meaning that the upper cervical spine was not recruited for compensation in order to maintain a horizontal gaze.
Fivefold higher rate of pseudarthrosis with polyetheretherketone interbody device than with structural allograft used for 1-level anterior cervical discectomy and fusion
Presented at the 2018 AANS/CNS Joint Section on Disorders of the Spine and Peripheral Nerves
Katie L. Krause, James T. Obayashi, Kelly J. Bridges, Ahmed M. Raslan and Khoi D. Than
Common interbody graft options for anterior cervical discectomy and fusion (ACDF) include structural allograft and polyetheretherketone (PEEK). PEEK has gained popularity due to its radiolucency and its elastic modulus, which is similar to that of bone. The authors sought to compare the rates of pseudarthrosis, a lack of solid bone growth across the disc space, and the need for revision surgery with the use of grafts made of allogenic bone versus PEEK.
The authors retrospectively reviewed 127 cases in which patients had undergone a 1-level ACDF followed by at least 1 year of radiographic follow-up. Data on age, sex, body mass index, tobacco use, pseudarthrosis, and the reoperation rate for pseudarthrosis were collected. These data were analyzed by performing a Pearson’s chi-square test.
Of 127 patients, 56 had received PEEK implants and 71 had received allografts. Forty-six of the PEEK implants (82%) were stand-alone devices. There were no significant differences between the 2 treatment groups with respect to patient age, sex, or body mass index. Twenty-nine (52%) of 56 patients with PEEK implants demonstrated radiographic evidence of pseudarthrosis, compared to 7 (10%) of 71 patients with structural allografts (p < 0.001, OR 9.82; 95% CI 3.836–25.139). Seven patients with PEEK implants required reoperation for pseudarthrosis, compared to 1 patient with an allograft (p = 0.01, OR 10.00; 95% CI 1.192–83.884). There was no significant difference in tobacco use between the PEEK and allograft groups (p = 0.586).
The results of this study demonstrate that the use of PEEK devices in 1-level ACDF is associated with a significantly higher rate of radiographically demonstrated pseudarthrosis and need for revision surgery compared with the use of allografts. Surgeons should be aware of this when deciding on interbody graft options, and reimbursement policies should reflect these discrepancies.
Enrico Ferrante and Michele Trimboli
Rob Dickerman, Julie Williamson and Matthew Bennett
Renaud Lafage, Ibrahim Obeid, Barthelemy Liabaud, Shay Bess, Douglas Burton, Justin S. Smith, Cyrus Jalai, Richard Hostin, Christopher I. Shaffrey, Christopher Ames, Han Jo Kim, Eric Klineberg, Frank Schwab, Virginie Lafage and the International Spine Study Group
The surgical correction of adult spinal deformity (ASD) often involves modifying lumbar lordosis (LL) to restore ideal sagittal alignment. However, corrections that include large changes in LL increase the risk for development of proximal junctional kyphosis (PJK). Little is known about the impact of cranial versus caudal correction in the lumbar spine on the occurrence of PJK. The goal of this study was to investigate the impact of the location of the correction on acute PJK development.
This study was a retrospective review of a prospective multicenter database. Surgically treated ASD patients with early follow-up evaluations (6 weeks) and fusions of the full lumbosacral spine were included. Radiographic parameters analyzed included the classic spinopelvic parameters (pelvic incidence [PI], pelvic tilt [PT], PI−LL, and sagittal vertical axis [SVA]) and segmental correction. Using Glattes’ criteria, patients were stratified into PJK and noPJK groups and propensity matched by age and regional lumbar correction (ΔPI−LL). Radiographic parameters and segmental correction were compared between PJK and noPJK patients using independent t-tests.
After propensity matching, 312 of 483 patients were included in the analysis (mean age 64 years, 76% women, 40% with PJK). There were no significant differences between PJK and noPJK patients at baseline or postoperatively, or between changes in alignment, with the exception of thoracic kyphosis (TK) and ΔTK. PJK patients had a decrease in segmental lordosis at L4-L5-S1 (−0.6° vs 1.6°, p = 0.025), and larger increases in segmental correction at cranial levels L1-L2-L3 (9.9° vs 7.1°), T12-L1-L2 (7.3° vs 5.4°), and T11-T12-L1 (2.9° vs 0.7°) (all p < 0.05).
Although achievement of an optimal sagittal alignment is the goal of realignment surgery, dramatic lumbar corrections appear to increase the risk of PJK. This study was the first to demonstrate that patients who developed PJK underwent kyphotic changes in the L4–S1 segments while restoring LL at more cranial levels (T12–L3). These findings suggest that restoring lordosis at lower lumbar levels may result in a decreased risk of developing PJK.
Katharine D. Harper, Dayna Phillips, Joseph M. Lopez and Zeeshan Sardar
Although compartment syndrome can occur in any compartment in the body, it rarely occurs in the paraspinal musculature and has therefore only been reported in a few case reports. Despite its rare occurrence, acute paraspinal compartment syndrome has been shown to occur secondary to reperfusion injury and traumatic and atraumatic causes. Diagnosis can be based on clinical examination findings, MRI or CT studies, or through direct measurement of intramuscular pressures. Conservative management should only be used in the setting of chronic presentation. Operative decompression via fasciotomy in cases of acute presentation may improve the patient’s symptoms and outcomes. When treating acute paraspinal compartment syndrome via surgical decompression, an important aspect is the anatomical consideration. Although grouped under one name, each paraspinal muscle is enclosed within its own fascial compartment, all of which must be addressed to achieve an adequate decompression. The authors present the case of a 43-year-old female patient who presented to the emergency department with increasing low-back and flank pain after a fall. Associated sensory deficits in a cutaneous distribution combined with imaging and clinical findings contributed to the diagnosis of acute traumatic paraspinal compartment syndrome. The authors discuss this case and describe their surgical technique for managing acute paraspinal compartment syndrome.
Mueez Waqar, Susan Huson, D. Gareth Evans, John Ealing, Konstantina Karabatsou, K. Joshi George and Calvin Soh
C2 nerve root neurofibromas have been reported frequently in patients with neurofibromatosis type 1 (NF1), although their genetic and imaging characteristics are unexplored. The aim of this study was to characterize genetic and spinal imaging findings in a large cohort of NF1 patients with C2 neurofibromas.
The authors performed a review of national NF1 referrals between 2009 and 2016. Inclusion criteria were at least 1 C2 root neurofibroma and cervical-spine or whole-spine MRI scans available for analysis. Blinded imaging review was performed by a neuroradiologist with an interest in NF1.
Fifty-four patients with 106 C2 neurofibromas were included. The median age was 32.5 years (range 15–61 years), and there were slightly more male patients (33 vs 21 female patients). Splice-site (30%) and missense (20%) variants were frequent. Spinal neurofibromas were distributed in all spine regions (65%) or in the cervical spine alone (22%). Most (93%) C2 neurofibromas were visible on MRI scans of the head. Intradural invasion and cord compression in the cervical spine included the C2 level in 95% and 80% of patients, respectively. Compared with all other cervical spine neurofibromas in these patients, C2 neurofibromas had higher rates of intraspinal extension (75% vs 32%; OR 6.20, 95% CI 3.85–9.97; p < 0.001), intradural invasion (53% vs 26%; OR 3.20, 95% CI 2.08–4.92; p < 0.001), and cord compression (25% vs 13%; OR 2.26, 95% CI 1.35–3.79; p = 0.002). However, C2 neurofibromas had lower rates of extraforaminal growth beyond the transverse process (12% vs 62%; OR 0.09, 95% CI 0.05–0.16; p < 0.001).
C2 neurofibromas are associated with an aggressive intraspinal phenotype, limited growth outside the spinal canal, and an uncommon genetic profile. These observations require future study.