Percutaneous surgery for treatment of epidural spinal cord compression and spinal instability

percutaneous-surgery-for-treatment-of-epidural-spinal

Neurosurg Focus 41 (4):E2, 2016

An emerging paradigm for treating patients with epidural spinal cord compression (ESCC) caused by metastatic tumors is surgical decompression and stabilization, followed by stereotactic radiosurgery. In the setting of rapid progressive disease, interruption or delay in return to systemic treatment can lead to a negative impact in overall survival. To overcome this limitation, the authors introduce the use of spinal laser interstitial thermotherapy (sLITT) in association with percutaneous spinal stabilization to facilitate a rapid return to oncological treatment.

Methods The authors retrospectively reviewed a consecutive series of patients with ESCC and spinal instability who were considered to be poor surgical candidates and instead were treated with sLITT and percutaneous spinal stabilization. Demographic data, Spine Instability Neoplastic Scale score, degree of epidural compression before and after the procedure, length of hospital stay, and time to return to oncological treatment were analyzed.

Results Eight patients were treated with thermal ablation and percutaneous spinal stabilization. The primary tumors included melanoma (n = 3), lung (n = 3), thyroid (n = 1), and renal cell carcinoma (n = 1). The median Karnofsky Performance Scale score before and after the procedure was 60, and the median hospital stay was 5 days (range 3–18 days). The median Spine Instability Neoplastic Scale score was 13 (range 12–16). The mean modified postoperative ESCC score (2.75 ± 0.37) was significantly lower than the preoperative score (4.5 ± 0.27) (Mann-Whitney test, p = 0.0044). The median time to return to oncological treatment was 5 days (range 3–10 days).

Conclusions The authors present the first cohort of sLITT associated with a percutaneous spinal stabilization for the treatment of ESCC and spinal instability. This minimally invasive technique can allow a faster recovery without prejudice of adjuvant systemic treatment, with adequate local control and spinal stabilization.

Predictive outcome factors in the young patient treated with lumbar disc herniation surgery

Surgical technique and effectiveness of microendoscopic discectomy for large uncontained lumbar disc herniations

J Neurosurg Spine 25:448–455, 2016

The aim of this study was to evaluate predictive factors for outcome after lumbar disc herniation surgery in young patients.

Methods In the national Swedish spine register, the authors identified 180 patients age 20 years or younger, in whom preoperative and 1-year postoperative data were available. The cohort was treated with primary open surgery due to lumbar disc herniation between 2000 and 2010. Before and 1 year after surgery, the patients graded their back and leg pain on a visual analog scale, quality of life by the 36-Item Short-Form Health Survey and EuroQol–5 Dimensions, and disability by the Oswestry Disability Index. Subjective satisfaction rate was registered on a Likert scale (satisfied, undecided, or dissatisfied). The authors evaluated if age, sex, preoperative level of leg and back pain, duration of leg pain, pain distribution, quality of life, mental status, and/or disability were associated with the outcome. The primary end point variable was the grade of patient satisfaction.

Results Lumbar disc herniation surgery in young patients normalizes quality of life according to the 36-Item Short- Form Health Survey, and only 4.5% of the patients were unsatisfied with the surgical outcome. Predictive factors for inferior postoperative patient-reported outcome measures (PROM) scores were severe preoperative leg or back pain, low preoperative mental health, and pronounced preoperative disability, but only low preoperative mental health was associated with inferiority in the subjective grade of satisfaction. No associations were found between preoperative duration of leg pain, distribution of pain, or health-related quality of life and the postoperative PROM scores or the subjective grade of satisfaction.

Conclusions Lumbar disc herniation surgery in young patients generally yields a satisfactory outcome. Severe preoperative pain, low mental health, and severe disability increase the risk of reaching low postoperative PROM scores, but are only of relevance clinically (low subjective satisfaction) for patients with low preoperative mental health.

Cervical radiographic parameters in 1- and 2-level anterior cervical discectomy and fusion

cervical-radiographic-parameters-in-1-and-2-level-anterior-cervical-discectomy-and-fusion

J Neurosurg Spine 25:421–429, 2016

Anterior cervical discectomy and fusion (ACDF) is one of the most commonly performed spine procedures. It can be used to correct cervical kyphotic deformity, which is the most common cervical deformity, and is often performed using lordotic interbody devices. Worsening of the cervical sagittal parameters is associated with decreased health-related quality of life. The study hypothesis is that through the use of machined lordotic allografts in ACDF, segmental and overall cervical lordosis can be maintained or increased, which will have a positive impact on overall cervical sagittal alignment.

Methods: Seventy-four cases of 1-level ACDF (ACDF1) and 2-level ACDF (ACDF2) (40 ACDF1 and 34 ACDF2 procedures) were retrospectively reviewed. Upright neutral lateral radiographs were assessed preoperatively and at 6 weeks and 1 year postoperatively. The measured radiographic parameters included focal lordosis, disc height, C2–7 lordosis, C1–7 lordosis, T-1 slope, and C2–7 sagittal vertical axis. Correlation coefficients were calculated to determine the relationships between these radiographic measurements.

Results: The mean values were as follows: preoperative focal lordosis was 0.574°, disc height was 4.48 mm, C2–7 lordosis was 9.66°, C1–7 lordosis was 42.5°, cervical sagittal vertebral axis (SVA) was 26.9 mm, and the T-1 slope was 33.2°. Cervical segmental lordosis significantly increased by 6.31° at 6 weeks and 6.45° at 1 year. C2–7 lordosis significantly improved by 1 year with a mean improvement of 3.46°. There was a significant positive correlation between the improvement in segmental lordosis and overall cervical lordosis. Overall cervical lordosis was significantly negatively correlated with cervical SVA. Improved segmental lordosis was not correlated with cervical SVA in ACDF1 patients but was significantly negatively correlated in ACDF2 patients. There was also a significant positive correlation between the T-1 slope and cervical SVA.

Conclusions In the study population, the improvement of focal lordosis was significantly correlated with an improvement in overall lordosis (C1–7 and C2–7), and overall lordosis as measured by the C2–7 Cobb angle was significantly negatively correlated with cervical SVA. Using lordotic cervical allografts, we successfully created and maintained significant improvement in cervical segmental lordosis at the 6-week and 1-year time points with values of 6.31° and 6.45°, respectively. ACDF is able to achieve statistically significant improvement in C2–7 cervical lordosis by the 1-year followup, with a mean improvement of 3.46°. Increasing the number of levels operated on resulted in improved cervical sagittal parameters. This establishes a baseline for further examination into the ability of multilevel ACDF to achieve cervical deformity correction through the intervertebral correction of lordosis.

Occipitocervical Fixation: A Single Surgeon’s Experience With 120 Patients

occipitocervical-fixation-a-single-surgeons-experience-with-120-patients

Neurosurgery 79:549–560, 2016

Occipitocervical junction instability can lead to serious neurological injury or death. Open surgical fixation is often necessary to provide definitive stabilization. However, long-term results are limited to small case series.

OBJECTIVE: To review the causes of occipitocervical instability, discuss the indications for surgical intervention, and evaluate long-term surgical outcomes after occipitocervical fixation.

METHODS: The charts of all patients undergoing posterior surgical fixation of the occipitocervical junction by the senior author were retrospectively reviewed. A total of 120 consecutive patients were identified for analysis. Patient demographic characteristics, occipitocervical junction pathology, surgical indications, and clinical and radiographic outcomes are reported.

RESULTS: The study population consisted of 64 male and 56 female patients with a mean age of 39.9 years (range, 7 months to 88 years). Trauma was the most common cause of instability, occurring in 56 patients (47%). Ninety patients (75%) were treated with screw/rod constructs; wiring was used in 30 patients (25%). The median number of fixated segments was 5 (O-C4). Structural bone grafts were implanted in all patients (100%). Preoperative neurological deficits were present in 83 patients (69%); 91% of those patients improved with surgery. Mean follow-up was 35.1 6 27.4 months (range, 0-123 months). Two patients died, and 10 were lost to follow-up before the end of the 6-month follow-up period. Fusion was confirmed in 107 patients (89.1%). The overall complication rate was 10%, including 3 patients with vertebral artery injuries and 2 patients who required revision surgery.

CONCLUSION: Occipitocervical fixation is a durable treatment option with acceptable morbidity for patients with occipitocervical instability.

Treatment of unstable thoracolumbar junction fractures

treatment-of-unstable-thoracolumbar-junction-fractures

Acta Neurochir (2016) 158:1883–1889

The surgical management of thoracolumbar burst fractures frequently involves posterior pedicle screw fixation. However, the application of short- or long-segment instrumentation is still controversial. The aim of this study was to compare the outcome of the short-segment fixation with inclusion of the fracture level (SSFIFL) versus the traditional long-segment fixation (LSF) for the treatment of unstable thoracolumbar junction fractures.

Methods From December 2009 to February 2014, 60 patients with unstable thoracolumbar junction fractures (T11-L2) were divided into two groups according to the number of instrumented levels. Group 1 included 30 patients treated by SSFIFL (six-screw construct including the fracture level). Group 2 included 30 patients treated by LSF (eight-screw construct excluding the fracture level). Local kyphosis angle (LKA), anterior body height (ABH), posterior body height (PBH), ABH/PBH ratio of fractured vertebra, and Asia Scale Impairment Scale were evaluated.

Results The two groups were similar in regard to age, sex, trauma etiology, fracture level, fracture type, neurologic status, pre-operative LKA, ABH, PBH, and ABH/PBH ratio and follow-up (p > 0.05). Reduction of post-traumatic kyphosis (assessed with LKA) and restoration of fracture-induced wedge shape of the vertebral body (assessed with ABH, PBH, and ABH/PBH ratio) at post-operative period were not significantly different between group 1 and group 2 (p = 0.234; p = 0.754). There was no significant difference between the two groups in term of correction loss at the last follow-up too (LKA was 15.97° ± 5.62° for SSFIFL and 17.76° ± 11.22° for LSF [p = 0.427]). Neurological outcome was similar in both groups.

Conclusions Inclusion of fracture level in a short-segment fixation for a thoracolumbar junction fractures results in a kyphosis correction and in a maintenance of the sagittal alignment similar to a long-segment instrumentation. Finally, this technique allowed us to save two or more segments of vertebral motion.

A comparison of the Wiltse versus midline approaches in degenerative conditions of the lumbar spine

wiltse

J Neurosurg Spine 25:332–338, 2016

The objective of this study was to determine if there is a significant difference in surgical site infection (SSI) when comparing the Wiltse and midline approaches for posterior instrumented interbody fusions of the lumbar spine and, secondarily, to evaluate if the reoperation rates and specific causes for reoperation were similar for both approaches.

Methods A total of 358 patients who underwent 1- or 2-level posterior instrumented interbody fusions for degenerative lumbar spinal pathology through either a midline or Wiltse approach were prospectively followed between March 2005 and January 2011 at a single tertiary care facility. A retrospective analysis was performed primarily to evaluate the incidence of SSI and the incidence and causes for reoperation. Secondary outcome measures included intraoperative complications, blood loss, and length of stay. A matched analysis was performed using the Fisher’s exact test and a logistic regression model. The matched analysis controlled for age, sex, comorbidities, number of index levels addressed surgically, number of levels fused, and the use of bone grafting.

Results All patients returned for follow-up at 1 year, and adverse events were followed for 2 years. The rate of SSI was greater in the midline group (8 of 103 patients; 7.8%) versus the Wiltse group (1 of 103 patients; 1.0%) (p = 0.018). Fewer additional surgical procedures were performed in the Wiltse group (p = 0.025; OR 0.47; 95% CI 0.23–0.95). Proximal adjacent segment failure requiring reoperation occurred more frequently in the midline group (15 of 103 patients; 14.6%) versus the Wiltse group (6 of 103 patients; 5.8%) (p = 0.048). Blood loss was significantly lower in the Wiltse group (436 ml) versus the midline group (703 ml); however, there was no significant difference between the 2 groups in intraoperative complications or length of stay.

Conclusions The patients who underwent the Wiltse approach had a decreased risk of wound breakdown and infection, less blood loss, and fewer reoperations than the midline patients. The risk of adjacent segment failure in short posterior constructs is lower with a Wiltse approach.

Esophageal perforation after anterior cervical spine surgery

esophageal-perforation-after-anterior-cervical-spine-surgery

J Neurosurg Spine 25:285–291, 2016

Esophageal perforation is a rare but well-known complication of anterior cervical spine surgery. The authors performed a systematic review of the literature to evaluate symptomatology, direct causes, repair methods, and associated complications of esophageal injury.

Methods A PubMed search that adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines included relevant clinical studies and case reports (articles written in the English language that included humans as subjects) that reported patients who underwent anterior spinal surgery and sustained some form of esophageal perforation. Available data on clinical presentation, the surgical procedure performed, outcome measures, and other individual variables were abstracted from 1980 through 2015.

Results The PubMed search yielded 65 articles with 153 patients (mean age 44.7 years; range 14–85 years) who underwent anterior spinal surgery and sustained esophageal perforation, either during surgery or in a delayed fashion. The most common indications for initial anterior cervical spine surgery in these cases were vertebral fracture/dislocation (n = 77), spondylotic myelopathy (n = 15), and nucleus pulposus herniation (n = 10). The most commonly involved spinal levels were C5–6 (n = 51) and C6–7 (n = 39). The most common presenting symptoms included dysphagia (n = 63), fever (n = 24), neck swelling (n = 23), and wound leakage (n = 18). The etiology of esophageal perforation included hardware failure (n = 31), hardware erosion (n = 23), and intraoperative injury (n = 14). The imaging modalities used to identify the esophageal perforations included modified contrast dye swallow studies, CT, endoscopy, plain radiography, and MRI. Esophageal repair was most commonly achieved using a modified muscle flap, as well as with primary closure. Outcomes measured in the literature were often defined by the time to oral intake following esophageal repair. Complications included pneumonia (n = 6), mediastinitis (n = 4), osteomyelitis (n = 3), sepsis (n = 3), acute respiratory distress syndrome (n = 2), and recurrent laryngeal nerve damage (n = 1). The mortality rate of esophageal perforation in the analysis was 3.92% (6 of 153 reported patients).

Conclusions Esophageal perforation after anterior cervical spine surgery is a rare complication. This systematic review demonstrates that these perforations can be stratified into 3 categories based on the timing of symptomatic onset: intraoperative, early postoperative (within 30 days of anterior spinal surgery), and delayed. The most common source of esophageal injury is hardware erosion or migration, each of which may vary in their time to symptomatic manifestation.

Complication Rates Associated With Adult Cervical Deformity Surgery

prospective-multicenter-assessment-of-early-complication-rates-associated-with-adult-cervical-deformity-surgery-in-78-patients

Neurosurgery 79:378–388, 2016

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

OBJECTIVE: To present early complication rates associated with ACD surgery.

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

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

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

Surgical Management of the Elderly With Traumatic Cervical Spinal Cord Injury

untitled

Neurosurgery 79:418–425, 2016

Aging of the population has modified the epidemiology of traumatic spinal cord injury (SCI) as evidenced by the establishment of a bimodal distribution of injuries with increased frequency of fall-related injuries among the elderly.

OBJECTIVE: To assess the economic impact of older age (65 years of age and older), using a cost-utility analysis, in the context of acute surgical management and rehabilitation of traumatic cervical SCI, given the paucity of economic studies involving elderly individuals with SCI.

METHODS: The cost-utility analysis was performed from the perspective of a public health care insurer. A time horizon of 6 months from SCI onset was used. Costs were estimated in 2014 US dollars. Utilities were generated from the Surgical Timing in Acute Spinal Cord Injury study.

RESULTS: The baseline analysis indicated that surgical and rehabilitative management of acute cervical SCI in the elderly (n = 17) is costlier, but similarly effective, than that in younger adults (n = 47). When considering acute spinal surgical management and rehabilitation of younger adults with SCI as the baseline, the incremental costeffectiveness ratio analysis revealed an additional cost of $5 655 557 per quality-adjusted life-year gained when managing elderly patients with traumatic cervical SCI. The probabilistic analysis confirmed that spinal surgery in the elderly is costlier, but similarly effective, in younger adults after SCI, even though there is no definitive dominance.

CONCLUSION: This economic analysis indicates that surgical management and rehabilitation of acute traumatic cervical SCI in the elderly are costlier but similarly effective compared with younger adults with similar impairment.

Benefit of Transforaminal Lumbar Interbody Fusion vs Posterolateral Spinal Fusion in Lumbar Spine Disorders

tlif-x-ray-lat

Neurosurgery 79:397–405, 2016

Despite increasing use and potential benefits of transforaminal lumbar interbody fusion (TLIF) compared with posterolateral spinal fusion (PSF), previous studies have not documented improved clinical outcomes with TLIF vs PSF.

OBJECTIVE: To compare the outcomes of TLIF with PSF in patients with spondylolisthesis, spinal stenosis, and adjacent level disease.

METHODS: The National Neurosurgical Quality and Outcomes Database was queried for patients who had a lumbar fusion. Eighty-five percent (1722) of enrolled cases had 12-month follow-up data. There were 306 PSF patients and 1230 TLIF patients. PSF cases within each diagnostic subgroup were propensity-matched to patients who had TLIF. Sufficient propensity-matched controls were available for patients with spondylolisthesis (109), spinal stenosis (63), and adjacent segment disease (47).

RESULTS: Operating room time, estimated blood loss, and length of stay were similar between PSF and TLIF in all 3 propensity-matched groups. In the spondylolisthesis group, there was a greater improvement in Oswestry Disability Index (ODI) with TLIF vs PSF at 3 months (19.4 vs 26.0, P = .009), 12 months (20.8 vs 29.3, P = .001), and in percentage reaching minimal clinically important difference at 12 months (80% vs 62%, P = .007). There were no differences in ODI improvement between PSF and TLIF in the stenosis or adjacent segment disease groups.

CONCLUSION: TLIF generated more favorable ODI outcomes than PSF for patients with spondylolisthesis, but not for patients with spinal stenosis or adjacent segment disease. There was also equivalence in operating room time and estimated blood loss between TLIF and PSF, potentially altering the long-standing assumption that PSF is a simpler procedure.

Dynamic posterior stabilization for degenerative lumbar spine disease

DSS

Eur Spine J (2016) 25:2563–2570

Dynamic stabilization of the degenerated spine was invented to overcome the negative side effects of fusion surgery like adjacent segment degeneration. Amongst various different implants DSS  is a pedicle-based dynamic device for stabilizing the spine and preserving motion. Nearly no clinical data of the implant have been reported so far. The current analysis presents results from a single spine surgeon who has been using DSS  for the past 5 years and recorded all treatment and outcome data in the international Spine Tango registry.

Materials/methods: From the prospectively documented overall patient pool 436 cases treated with DSS  could be identified. The analysis was enhanced with a mailing of COMI patient questionnaires for generating longer-term follow-ups up to 4 years.

Results: 387 patients (189 male, 198 female; mean age 67.3 years) with degenerative lumbar spinal disease including degenerative spondylolisthesis (6.1 %) could be evaluated. The type of degeneration was mainly spinal stenosis (89.9 %). After a mean follow-up of 1.94 years, the COMI score and NRS back and leg pain improved significantly and to a clinically relevant extent. The postoperative trend analysis could not determine a relevant deterioration of these outcomes until 4 years postoperative. 10 patients were revised (2.6 %) and the implant was removed; in most cases, a fusion was performed. Another 5 cases (1.3 %) had an extension of the dynamic stabilization system to the adjacent level. 84.2 % of patients rated that the surgery had helped a lot or had helped.

Discussion: The results of this large consecutive series with a follow-up up to 4 years could demonstrate a good and stable clinical outcome after posterior dynamic stabilization with DSS. For degenerative diseases of the lumbar spine, this treatment seems to be a valid alternative to fusion surgery.

Surgery for adult spondylolisthesis: a systematic review of the evidence

spondylolistesis

Eur Spine J (2016) 25:2359–2367

Surgery for isthmic and degenerative spondylolisthesis (SL) in adults is carried out very frequently in everyday practice. However, it is still unclear whether the results of surgery are better than those of conservative treatment and whether decompression alone or instrumented fusion with decompression should be recommended. In addition, the role of reduction is unclear.

Four clinically relevant key questions were addressed in this study: (1) Is surgery more successful than conservative treatment in relation to pain and function in adult patients with isthmic SL? (2) Is surgery more successful than conservative treatment in relation to pain and function in adult patients with degenerative SL? (3) Is instrumented fusion with decompression more successful in relation to pain and function than decompression alone in adult patients with degenerative SL and spinal canal stenosis? (4) Is instrumented fusion with reduction more successful in relation to pain and function than instrumented fusion without reduction in adult patients with isthmic or degenerative SL?

A systematic PubMed search was carried out to identify randomized and nonrandomized controlled trials on these topics. Papers were analyzed systematically in a search for the best evidence.A total of 18 studies was identified and analyzed: two for question 1, eight for question 2, four for question 3, and four for question 4.

Surgery appears to be better than conservative treatment in adults with isthmic SL (poor evidence) and also in adults with degenerative SL (good evidence). Instrumented fusion with decompression appears to be more successful than decompression alone in adults with degenerative SL and spinal stenosis (poor evidence). Reduction and instrumented fusion does not appear to be more successful than instrumented fusion without reduction in adults with isthmic or degenerative SL (moderate evidence).

Biodegradable anterior cervical plates

biodegradable anterior cervical plate

J Neurosurg Spine 25:205–212, 2016

The purpose of this study was to present an initial surgical experience in the management of 1- or 2-level degenerative disc disease of the cervical spine using biodegradable anterior cervical plates (bACPs) in anterior cervical discectomy and fusion (ACDF). The authors also aimed to provide insight into this critical and controversial clinical issue by clarifying outcomes for patients receiving bACPs and by comparing their outcomes with those achieved using a traditional metallic anterior cervical plate (mACP) implant.

Methods: A retrospective review was conducted for 2 series of patients who had undergone ACDF using either bACP (31 patients, 38 segments) or mACP (47 patients, 57 segments) instrumentation. The patients were followed up for a mean 13.5 ± 0.9 months (range 12–18 months) in the bACP group and 14.8 ± 1.5 months (range 14–22 months) in the mACP group. Clinical outcomes were determined according to scores on the visual analog scale (VAS), the modified Japanese Orthopaedic Association (mJOA) scoring system, and Odom’s criteria. Radiological images were used to assess fusion rates, intervertebral height, Cobb’s angle, and the width of prevertebral soft tissue.

Results: Both VAS and mJOA scores were significantly improved at each follow-up in both groups. Excellent or good results according to Odom’s criteria were achieved in 93.5% (29/31) of patients in the bACP group and 93.6% (44/47) of patients in the mACP group. At 6 months postoperatively, the fusion rate was 94.7% (36/38) in the bACP group and 96.5% (55/57) in the mACP group, but subsidence of the intervertebral space at the surgical level was more evident in the bACP group. Angulation, as measured by Cobb’s angle, demonstrated obvious healing in both groups, while better maintenance was observed in the mACP group. The local inflammatory reaction was uneventful during follow-up. Dysphonia and dysphagia were observed in both groups during the follow-up.

Conclusions: The relatively comparable early clinical and radiographic outcomes and the overall acceptable complication rates for bACP and mACP use suggest that bACPs could be used as alternative instruments in ACDF. Mild graft resorption was noted without evidence of symptoms. However, the prospective efficacy of biodegradable instrumentation can only be elucidated with longer-term observation.

Resection of spinal column tumors utilizing image-guided navigation: a multicenter analysis

IG spinal tumor resection.1

Neurosurg Focus 41 (2):E15, 2016

The use of intraoperative stereotactic navigation has become more available in spine surgery. The authors undertook this study to assess the utility of intraoperative CT navigation in the localization of spinal lesions and as an intraoperative tool to guide resection in patients with spinal lesions.

Methods This was a retrospective multicenter study including 50 patients from 2 different institutions who underwent biopsy and/or resection of spinal column tumors using image-guided navigation. Of the 50 cases reviewed, 4 illustrative cases are presented. In addition, the authors provide a description of surgical technique with image guidance.

Results The patient group included 27 male patients and 23 female patients. Their average age was 61 ± 17 years (range 14–87 years). The average operative time (incision to closure) was 311 ± 188 minutes (range 62–865 minutes). The average intraoperative blood loss was 882 ± 1194 ml (range 5–7000 ml). The average length of hospitalization was 10 ± 8.9 days (range 1–36 days). The postoperative complications included 2 deaths (4.0%) and 4 radiculopathies (8%) secondary to tumor burden.

Conclusions: O-arm 3D imaging with stereotactic navigation may be used to localize lesions intraoperatively with real-time dynamic feedback of tumor resection. Stereotactic guidance may augment resection or biopsy of primary and metastatic spinal tumors. It offers reduced radiation exposure to operating room personnel and the ability to use minimally invasive approaches that limit tissue injury. In addition, acquisition of intraoperative CT scans with real-time tracking allows for precise targeting of spinal lesions with minimal dissection.

Validity and Reliability of a Measurement of Objective Functional Impairment in Lumbar Degenerative Disc Disease: The Timed Up and Go (TUG) Test

Validity and Reliability of a Measurement of Objective Functional Impairment in Lumbar Degenerative Disc Disease- The Timed Up and Go (TUG) Test

Neurosurgery 79:270–278, 2016

There are few objective measures of functional impairment to support clinical decision making in lumbar degenerative disc disease (DDD).

OBJECTIVE: We present the validation (and reliability measures) of the Timed Up and Go (TUG) test.

METHODS: In a prospective, 2-center study, 253 consecutive patients were assessed using the TUG test. A representative cohort of 110 volunteers served as control subjects. The TUG test values were assessed for validity and reliability.

RESULTS: The TUG test had excellent intra- (intraclass correlation coefficient: 0.97) and interrater reliability (intraclass correlation coefficient: 0.99), with a standard error of measurement of 0.21 and 0.23 seconds, respectively. The validity of the TUG test was demonstrated by a good correlation with the Visual Analog Scale (VAS) back (Pearson’s correlation coefficient [PCC]: 0.25) and VAS (PCC: 0.29) leg pain, functional impairment (Roland-Morris Disability Index [PCC: 0.38] and Oswestry Disability Index [PCC: 0.34]), as well as with health-related quality of life (Short Form-12 Mental Component Summary score [PCC: 20.25], Short Form-12 Physical Component Summary score [PCC: 20.32], and EQ-5D [PCC: 20.28]). The upper limit of “normal” was 11.52 seconds. Mild (lower than the 33rd percentile), moderate (33rd to 66th percentiles), and severe objective functional impairment (higher than the 66th percentile) as determined by the TUG test was <13.4 seconds, 13.4 to 18.4 seconds, and >18.4 seconds, respectively.

CONCLUSION: The TUG test is a quick, easy-to-use, valid, and reliable tool to evaluate objective functional impairment in patients with lumbar degenerative disc disease. In the clinical setting, patients scoring a TUG test time of over 12 seconds can be considered to have functional impairment.

How to predict return to work after lumbar discectomy

How to predict return to work after lumbar discectomy- answers from the NeuroPoint-SD registry

J Neurosurg Spine 25:181–186, 2016

To date, the factors that predict whether a patient returns to work after lumbar discectomy are poorly understood. Information on postoperative work status is important in analyzing the cost-effectiveness of the procedure.

Methods An observational prospective cohort study was completed at 13 academic and community sites (Neuro- Point–Spinal Disorders [NeuroPoint-SD] registry). Patients undergoing single-level lumbar discectomy were included. Variables assessed included age, sex, body mass index (BMI), SF-36 physical function score, Oswestry Disability Index (ODI) score, presence of diabetes, smoking status, systemic illness, workers’ compensation status, and preoperative work status. The primary outcome was working status within 3 months after surgery. Stepwise logistic regression analysis was performed to determine which factors were predictive of return to work at 3 months following discectomy.

Results There were 127 patients (of 148 total) with data collected 3 months postoperatively. The patients’ average age at the time of surgery was 46 ± 1 years, and 66.9% of patients were working 3 months postoperatively. Statistical analyses demonstrated that the patients more likely to return to work were those of younger age (44.5 years vs 50.5 years, p = 0.008), males (55.3% vs 28.6%, p = 0.005), those with higher preoperative SF-36 physical function scores (44.0 vs 30.3, p = 0.002), those with lower preoperative ODI scores (43.8 vs 52.6, p = 0.01), nonsmokers (83.5% vs 66.7%, p = 0.03), and those who were working preoperatively (91.8% vs 26.2%, p < 0.0001). When controlling for patients who were working preoperatively (105 patients), only age was a statistically significant predictor of postoperative return to work (44.1 years vs 51.1 years, p = 0.049).

Conclusions In this cohort of lumbar discectomy patients, preoperative working status was the strongest predictor of postoperative working status 3 months after surgery. Younger age was also a predictor. Factors not influencing return to work in the logistic regression analysis included sex, BMI, SF-36 physical function score, ODI score, presence of diabetes, smoking status, and systemic illness. Clinical trial registration no.: 01220921 (clinicaltrials.gov).

First Human Implantation of a Bioresorbable Polymer Scaffold for Acute Traumatic Spinal Cord Injury

First Human Implantation of a Bioresorbable Polymer Scaffold for Acute Traumatic Spinal Cord Injury

Neurosurgery 79:E305–E312, 2016

A porous bioresorbable polymer scaffold has previously been tested in preclinical animal models of spinal cord contusion injury to promote appositional healing, spare white matter, decrease posttraumatic cysts, and normalize intraparenchymal tissue pressure. This is the first report of its human implantation in a spinal cord injury patient during a pilot study testing the safety and feasibility of this technique (ClinicalTrials.gov Identifier: NCT02138110).

CLINICAL PRESENTATION: A 25-year-old man had a T11-12 fracture dislocation sustained in a motocross accident that resulted in a T11 American Spinal Injury Association Impairment Scale (AIS) grade A traumatic spinal cord injury. He was treated with acute surgical decompression and spinal fixation with fusion, and enrolled in the spinal scaffold study. A 2 x 10 mm bioresorbable scaffold was placed in the spinal cord parenchyma at T12. The scaffold was implanted directly into the traumatic cavity within the spinal cord through a dorsal root entry zone myelotomy at the caudal extent of the contused area. By 3 months, his neurological examination improved to an L1 AIS grade C incomplete injury. At 6-month postoperative follow-up, there were no procedural complications or apparent safety issues related to the scaffold implantation.

CONCLUSION: Although longer-term follow-up and investigation are required, this case demonstrates that a polymer scaffold can be safely implanted into an acutely contused spinal cord. This is the first human surgical implantation, and future outcomes of other patients in this clinical trial will better elucidate the safety and possible efficacy profile of the scaffold.

Three-Year Follow-up of the Prospective, Randomized, Controlled Trial of Coflex Interlaminar Stabilization vs Instrumented Fusion in Patients With Lumbar Stenosis

Three-Year Follow-up of the Prospective, Randomized, Controlled Trial of Coflex Interlaminar Stabilization vs Instrumented Fusion in Patients With Lumbar Stenosis

Neurosurgery 79:169–181, 2016

Traditional surgical options for the treatment of symptomatic lumbar spinal stenosis include decompression alone vs decompression and fusion; both options have potential limitations.

OBJECTIVE: To report the 36-month follow-up analysis of the coflex Interlaminar Stabilization (Paradigm Spine, LLC, New York, New York) after decompression, examined under a Food and Drug Administration investigational device exemption clinical trial, which is intended to provide stabilization after decompression while preserving normal segmental motion at the treated level.

METHODS: The coflex trial was a prospective, randomized investigational device exemption study conducted at 21 clinical sites in the United States. Baseline and followup visits collected demographics, clinical, and radiographic status. The primary endpoint was a measure of composite clinical success 24 months postoperatively. For this current 36-month analysis, composite clinical success was calculated using analogous methods.

RESULTS: Composite clinical success at 36 months was achieved by 62.2% among 196 coflex Interlaminar Stabilization patients and 48.9% among 94 fusion patients (difference = 13.3%, 95% confidence interval, 1.1%-25.5%, P = .03). Bayesian posterior probabilities for noninferiority (margin = 210%) and superiority of cofle Interlaminar Stabilization vs fusion were .0.999 and 0.984, respectively. Substantial and comparable improvements were observed in both groups for patient-reported outcomes, although the percentage with a clinically significant improvement ($15) in the Oswestry Disability Index seemed larger for the coflex Interlaminar Stabilization group relative to the fusion group (P = .008). Radiographic measurements maintained index level and adjacent level range of motion in coflex Interlaminar Stabilization patients, although range of motion at the level superior to fusion was significantly increased (P = .005).

CONCLUSION: Coflex Interlaminar Stabilization for stenosis is proven to be effective and durable at improving overall composite clinical success without altering normal spinal kinematic motion at the index level of decompression or adjacent levels.

Cost Utility Analysis of the Cervical Artificial Disc vs Fusion for the Treatment of 2-Level Symptomatic Degenerative Disc Disease: 5-Year Follow-up

mobi-c

Neurosurgery 79:135–145, 2016

The cervical total disc replacement (cTDR) was developed to treat cervical degenerative disc disease while preserving motion.

OBJECTIVE: Cost-effectiveness of this intervention was established by looking at 2-year follow-up, and this update reevaluates our analysis over 5 years.

METHODS: Data were derived from a randomized trial of 330 patients. Data from the 12- Item Short Form Health Survey were transformed into utilities by using the SF-6D algorithm. Costs were calculated by extracting diagnosis-related group codes and then applying 2014 Medicare reimbursement rates. A Markov model evaluated qualityadjusted life years (QALYs) for both treatment groups. Univariate and multivariate sensitivity analyses were conducted to test the stability of the model. The model adopted both societal and health system perspectives and applied a 3% annual discount rate.

RESULTS: The cTDR costs $1687 more than anterior cervical discectomy and fusion (ACDF) over 5 years. In contrast, cTDR had $34 377 less productivity loss compared with ACDF. There was a significant difference in the return-to-work rate (81.6% compared with 65.4% for cTDR and ACDF, respectively; P = .029). From a societal perspective, the incremental cost-effective ratio (ICER) for cTDR was 2$165 103 per QALY. From a health system perspective, the ICER for cTDR was $8518 per QALY. In the sensitivity analysis, the ICER for cTDR remained below the US willingness-to-pay threshold of $50 000 per QALY in all scenarios (2$225 816 per QALY to $22 071 per QALY).

CONCLUSION: This study is the first to report the comparative cost-effectiveness of cTDR vs ACDF for 2-level degenerative disc disease at 5 years. The authors conclude that, because of the negative ICER, cTDR is the dominant modality.

Natural Head Posture in the Setting of Sagittal Spinal Deformity

Natural Head Posture in the Setting of Sagittal Spinal Deformity

Neurosurgery 79:108–115, 2016

The maintenance of horizontal gaze is an essential function of upright posture and global sagittal spinal alignment. Horizontal gaze is classically measured by the chin-brow vertical angle (CBVA), which is not readily measured on most lateral spine radiographs.

OBJECTIVE: To evaluate relations between CBVA and the slope of the line of sight, the slope of McGregor’s line (McGS), and Oswestry Disability Index.

METHODS: Patients were identified from a single center database of 531 spine patients who underwent full-body EOS x-rays. Correlations between CBVA, the slope of the line of sight, and McGS were assessed. Using a quadratic regression with Oswestry Disability Index and CBVA, windows of low disability were identified. Comparison of sagittal spinopelvic parameters was carried out between patients with “ascending gaze” and “neutral position.”

RESULTS: Three hundred three patients were included (74% female, mean age 54.8 years, body mass index 26.6 6 6.0 kg/m2). CBVA strongly correlated with the slope of the line of sight (r = 0.996) and McGS (r = 0.862). Regression studies between Oswestry Disability Index and CBVA yielded a range of values corresponding to low disability (24.7 degrees to 17.7 degrees). Similarly, a low disability range for the slope of the line of sight (25.1 degrees to 18.5 degrees) and McGS (25.7 degrees to 14.3 degrees) was computed. Patients with “ascending gaze” had a worse spinopelvic alignment than “neutral position” patients.

CONCLUSION: The slope of the line of sight and McGS correlated strongly with CBVA and can be used as surrogate measures. The range of values for these measures corresponding to low disability was identified. These values can be used as a general guideline to assess alignment for diagnostic purposes. Cervical compensatory mechanism may modify the natural head position in sagittally misaligned patients.