Spine surgery has been growing rapidly as a neurosurgical operation, with an increase of 220% over a 15-year period. Intraoperative blood transfusion is a major outcome determinant of spine procedures. Various approaches, including pharmacologic and nonpharmacologic therapies, have been tested to decrease both intraoperative and postoperative blood loss. The aim of this systematic review is to report clinical evidence on the relationship between intraoperative blood loss (primary outcome) and on transfusion requirements and postoperative complications (secondary outcomes) in patients undergoing spine surgery. A literature search of PubMed database was performed using 5 key words: spine surgery and transfusion; spine surgery and blood loss; spine surgery and blood complications; spine surgery and deep vein thrombosis; and spine surgery and pulmonary embolism. Clinical reports (randomized controlled trials, prospective and retrospective studies, and case reports) were selected. A total of 473 articles were examined; 450 were excluded, and 24 were selected for this systematic review. Selected articles were categorized into 3 subchapters: (1) drugs active on coagulation (12 studies): tranexamic acid, aminocaproic acid, aprotinin, and recombinant activated factor VII; (2) drugs not active on coagulation (5 studies): ketorolac, epoetin alfa, magnesium sulfate, propofol/sevoflurane, and omega-3 and fish oil; (3) nonpharmacologic approaches (7 studies): surgical tips, patient positioning, and general or spinal anesthesia. Several studies have shown a significant reduction in intraoperative bleeding during spine surgery and in the requirement for blood transfusion.
OBJECTIVE: Spine surgery has been identified as a significant source of healthcare expenditures in the United States. Prolonged hospitalization has been cited as one source of increased spending, and there has been drive from providers and payors alike to decrease inpatient stays. One strategy currently being explored is the use of Enhanced Recovery After Surgery (ERAS) protocols. Here, the authors review the literature on adult spine ERAS protocols, focusing on clinical benefits and cost reductions. They also conducted a quantitative meta-analysis examining the following: 1) length of stay (LOS), 2) complication rate, 3) wound infection rate, 4) 30-day readmission rate, and 5) 30-day reoperation rate. METHODS: Using the PRISMA guidelines, a search of the PubMed/Medline, Web of Science, Cochrane Reviews, Embase, CINAHL, and OVID Medline databases was conducted to identify all full-text articles in the English-language literature describing ERAS protocol implementation for adult spine surgery. A quantitative meta-analysis using random-effects modeling was performed for the identified clinical outcomes using studies that directly compared ERAS protocols with conventional care. RESULTS: Of 950 articles reviewed, 34 were included in the qualitative analysis and 20 were included in the quantitative analysis. The most common protocol types were general spine surgery protocols and protocols for lumbar spine surgery patients. The most frequently cited benefits of ERAS protocols were shorter LOS (n = 12), lower postoperative pain scores (n = 6), and decreased complication rates (n = 4). The meta-analysis demonstrated shorter LOS for the general spine surgery (mean difference -1.22 days [95% CI -1.98 to -0.47]) and lumbar spine ERAS protocols (-1.53 days [95% CI -2.89 to -0.16]). Neither general nor lumbar spine protocols led to a significant difference in complication rates. Insufficient data existed to perform a meta-analysis of the differences in costs or postoperative narcotic use. CONCLUSIONS: Present data suggest that ERAS protocol implementation may reduce hospitalization time among adult spine surgery patients and may lead to reductions in complication rates when applied to specific populations. To generate high-quality evidence capable of supporting practice guidelines, though, additional controlled trials are necessary to validate these early findings in larger populations.
BACKGROUND: Instrumented spinal fusion surgery is increasingly performed. Breaching of the pedicle occurs in 3-55% of screws; clinically significant screw misplacements occur in 0-7% of all transpedicular screw placements. Several techniques have reduced this incidence but none gained popularity due to cost as well as staff issues. Surgical robots offer distinct added value in accuracy and minimal invasiveness. The aim of this study is to introduce the SpineAssist--a novel spine surgery miniature robot, to discuss the various reasons that had prevented full success with its use, to identify patients related, technical related, and surgeon related issues, and to offer ways to avoid them. METHODS: The SpineAssist miniature robotic system is presented, including a short description of the system, its mode of action and a short summary of the surgical procedure.15 patients had undergone lumbar fusion procedures using the robotic system as part of clinical trials in two Israeli spine centres. A group of 9 procedures was identified within this prospective cohort. This group represents a wide array of technical challenges and human errors which were encountered during the clinical development phase of the SpineAssist. These 9 cases were conducted in two different sites by different surgical teams, over a period of 9 months, with an average interval of 7 weeks between consecutive cases. The cases were analysed for patient, system, surgeon and technical issues causing the difficulty. Conclusions were drawn as to how to avoid these hurdles in the future. RESULTS: In six cases the system operated smoothly, resulting in accurate screws placement according to the pre-operative plan, this was confirmed by a post-operative CT scan. Technical and surgical challenges which are associated with the system early development stage were encountered during 9 procedures. On the technical side, the following phenomena were evident: 1) failure of the software to automatically achieve satisfying CT-to-fluoro image registration and 2) failure of the hospital's peripheral equipment/logistics preventing registration. On the clinical side of things, the following issues were encountered: 1) failure to avoid excessive pressure on the guiding arm caused by surrounding soft tissues, leading to a shift in the entry point and trajectory of the tool guide. 2) a surgeon applying too much force on the tool guide at the tip of the robotic arm, causing deviation from plan. 3) pre-operative plan out of the reach of the robot arm and 4) attachment of the clamp to the spinous process in a suboptimal orientation. CONCLUSIONS: It is expected that following a steep learning curve in the range of 5-10 cases, recommended to take place within 2-3 weeks time, the surgical team will gain sufficient experience in operating the SpineAssist miniature robotic device in order to achieve excellent surgical results. The system may be used for wide range of applications including but not limited to pedicle screws, trans-facet and trans-laminar screws, biopsy needles, vertebroplasty or kyphoplasty tools and more. The preoperative plan has to be logical, intraoperative fluoro images taken with care, gentle surgical technique must be kept - maintaining the integrity of the posterior elements, and avoiding pressure between the robot arms and the soft tissues. During the clinical development phase discussed in this study, both teams used an early version of the system. Based on the results of this study several significant software and hardware improvements have already been implemented. It is our hope that describing and analysing our findings will help in planning and preparing for the clinical utilization of the SpineAssist system in future sites and will shorten their learning curve. By the time this article is published wider clinical experience will have been gathered and we expect to soon follow up with an analysis of clinical utilization of this system in a larger study group.
BACKGROUND: Prescription opioid use and opioid-related deaths have become an epidemic in the United States, leading to devastating economic and health ramifications. Opioids are the most commonly prescribed drug class to treat low back pain, despite the limited body of evidence supporting their efficacy. Furthermore, preoperative opioid use prior to spine surgery has been reported to range from 20% to over 70%, with nearly 20% of this population being opioid dependent. OBJECTIVE: To review the medical literature on the effect of preoperative opioid use in outcomes in spine surgery. METHODS: We reviewed manuscripts published prior to February 1, 2019, exploring the effect of preoperative opioid use on outcomes in spine surgery. We identified 45 articles that analyzed independently the effect of preoperative opioid use on outcomes (n = 32 lumbar surgery, n = 19 cervical surgery, n = 7 spinal deformity, n = 5 "other"). RESULTS: Preoperative opioid use is overwhelmingly associated with negative surgical and functional outcomes, including postoperative opioid use, hospitalization duration, healthcare costs, risk of surgical revision, and several other negative outcomes. CONCLUSION: There is an urgent and unmet need to find and apply extensive perioperative solutions to combat opioid use, particularly in patients undergoing spine surgery. Further investigations are necessary to determine the optimal method to treat such patients and to develop opioid-combative strategies in patients undergoing spine surgery.
BACKGROUND: We aimed to explore the effect of intraoperative S-ketamine on analgesic consumption and pain one year after spine surgery in chronic opioid-dependent patients undergoing spinal fusion surgery. METHODS: Single-centre, randomized, blinded trial of 147 patients. INTERVENTION: infusion or placebo. MAIN OUTCOMES: Analgesic use, pain (visual analogue scale 0-100 mm [VAS]) and labour market attachment one year after surgery assessed by written questionnaires. RESULTS: Response rate was 67%. One year after surgery, the daily use of oral morphine equivalents was lower in the ketamine group versus the placebo group: 0 (0-20) mg versus 20 (0-62) mg, (p = 0.02), and fewer patients had a daily use of any analgesics in the ketamine group versus placebo group, 42% (95% CI 23-61) versus 74% (95% CI 58-87), (p = 0.04). Mobilization pain was lower in the ketamine group compared to the placebo group: Median difference 17 mm (95% CI -30 to -3), (p = 0.02). Pain at rest was lower in the ketamine group compared to the placebo group with median difference: 13 mm (95% CI -23 to -3), (p = 0.01). Further, labour market attachment was better in the ketamine group, (p = 0.02). CONCLUSION: Intraoperative ketamine may reduce analgesic use, pain, and improve labour market attachment one year after spine surgery in a chronic opioid-dependent population. SIGNIFICANCE: This randomized clinical trial shows that intraoperative ketamine may reduce opioid use and pain and improve labour market attachment one year after spine surgery in an opioid-dependent population.
Frailty is a condition characterized by a high vulnerability to low-power stressor. Frailty increases with age and is associated with higher complications and mortality. Several indexes have been used to quantify frailty. Spine diseases, both degenerative and oncologic, frequently require surgery which is related to complications and mortality. Aim of the present systematic review was to collect the most frequently used frailty indexes in clinics to predict surgical outcomes in patients affected by spine diseases, taking into account gender differences. Three databases were employed, and 29 retrospective clinical studies were included in this systematic review. The identified spine pathologies were primary and metastatic spine tumors, adult spine deformity (ASD), degenerative spine disease (DSD), cervical deformity (CD) and other pathologies that affected lumbar spine or multiple spine levels. Eleven indexes were identified: modified Frailty Index (mFI), Adult spinal deformity frailty index (ASD-FI), mFI-5, Metastatic Spinal Tumor Frailty Index (MSTFI), Fried criteria, Cervical deformity frailty index (CD-FI), Spinal tumor frailty index (STFI), Frailty Phenotype criteria (FP), Frailty Index (FI), FRAIL scale and Modified CD-FI (mCD-FI). All these indexes correlated well with minor and major postoperative complications, mortality and length of stay in hospital. Results on gender differences and frailty are still conflicting, although few studies show that women are more likely to develop frailty and more complications in the post-operative period than men. This systematic review could help the surgeon in the adoption of frailty indexes, before the operation, and in preventing complications in frail patients.
OBJECT: Proximal junctional kyphosis (PJK) is a common and significant complication after corrective spinal deformity surgery. The object of this study was to compare-based on clinical outcomes, postoperative proximal junctional kyphosis rates, and prevalence of revision surgery-proximal thoracic (PT) and distal thoracic (DT) upper instrumented vertebra (UIV) in adults who underwent spine fusion to the sacrum for the treatment of spinal deformity. METHODS: In this retrospective study the authors evaluated clinical and radiographic data from consecutive adults (age > 21 years) with a deformity treated using long instrumented posterior spinal fusion to the sacrum in the period from 2007 to 2009. The PT group included patients in whom the UIV was between T-2 and T-5, whereas the DT group included patients in whom the UIV level was between T-9 and L-1. Perioperative surgical data were compared between the PT and DT groups. Additionally, segmental, regional, and global spinal alignments, as well as the sagittal Cobb angle at the proximal junction, were analyzed on preoperative, early postoperative, and final standing 36-in. radiographs. Patient-reported outcome measurements (visual analog scale, Scoliosis Research Society Patient Questionnaire-22, Oswestry Disability Index, and the 36-Item Short-Form Health Survey) were compared. RESULTS: Eighty-nine patients, 22 males and 67 females, had a minimum follow-up of 2 years, and thus were eligible for participation in this study. Sixty-seven patients were in the DT group and 22 were in the PT group. Operative time (p = 0.387) and estimated blood loss (p < 0.05) were slightly higher in the PT group. The overall rate of revision surgery was 48.0% and 54.5% in the DT and PT groups, respectively (p = 0.629). The prevalence of PJK according to radiological criteria was 34% in the DT group and 27% in the PT group (p = 0.609). The percent of patients with PJK that required surgical correction (surgical PJK) was 11.9% (8 of 67) in the DT group and 9.1% (2 of 22) in the PT group (p = 1.0). The onset of surgical PJK was significantly earlier than radiological PJK in the DT group (p < 0.01). The types of PJK were different in the PT and DT groups. Compression fracture at the UIV was more prevalent in the DT group, whereas subluxation was more prevalent in the PT group. Postoperatively, the PT group had less thoracic kyphosis (p = 0.02), less sagittal imbalance (p < 0.01), and less pelvic tilt (p = 0.04). In the DT group, early postoperative radiographs demonstrated that the proximal junctional angle of patients with surgical PJK was greater than in those without PJK and those with radiological PJK (p < 0.01). Clinical outcomes were significantly improved in both groups, and there was no significant difference between the groups. CONCLUSIONS: Both PT and DT UIVs improve segmental and global sagittal plane alignment as well as patient-reported quality of life in those treated for adult spinal deformity. The prevalence of PJK was not different in the PT and DT groups. However, compression fracture was the mechanism more frequently observed with DT PJK, and subluxation was the mechanism more frequently observed in PT PJK. Strategies to avoid PJK may include vertebral augmentation to prevent fracture at the DT spine and mechanical means to prevent vertebral subluxation at the PT spine.
STUDY DESIGN: Retrospective review. OBJECTIVE: Evaluation of the impact of diabetes on lumbar spine surgery. SUMMARY OF BACKGROUND DATA: Characteristics of diabetes that increase the risk of postoperative complications and poor surgical outcomes after lumbar spine surgery remain unclear. METHODS: The demographic and clinical data of diabetic and nondiabetic patients, 50 years or older, undergoing lumbar spine surgery were reviewed. Japanese Orthopaedic Association and visual analogue scale scores for low back pain, leg pain, and numbness were assessed as perioperative outcomes. Analysis of covariance was used for comparison of perioperative outcomes to adjust for differences between the groups, and a proportional odds model was used to compute the odds ratio of poor improvement in each outcome. RESULTS: Forty-one patients with diabetes were compared with 124 patients without diabetes. Visual analogue scale scores of final low back pain was higher for patients with than without diabetes (29.3 vs. 17.9, P = 0.013). Complications were similar in patients with and without diabetes except for nonunion after fusion surgery (20% vs. 3%, P = 0.095). When stratified by surgical procedure, final low back pain was significantly higher for patients with diabetes who underwent fusion surgery (39.1 vs. 17.4, P = 0.001). Patients with glycosylated hemoglobin of 6.5% or more displayed a 2-fold increase only in the odds ratio (OR) of poor improvement of low back pain (OR = 2.37; 95% confidence interval [CI], 0.99-5.70). Patients having diabetes for 20 years or more were more likely to experience poor improvement of low back pain and leg numbness (OR = 4.95; 95% CI, 1.69-14.5 and OR = 2.80; 95% CI, 0.98-7.94, respectively). Insulin use was associated with an increased OR for poor improvement of leg numbness (OR = 4.49; 95% CI, 1.24-16.3). CONCLUSION: Longstanding diabetes, poor glycemic control, and insulin use might be associated with poor postoperative improvement.
BACKGROUND: Augmented reality mediated spine surgery is a novel technology for spine navigation. Benchmark cadaveric data have demonstrated high accuracy and precision leading to recent regulatory approval. Absence of respiratory motion in cadaveric studies may positively bias precision and accuracy results and analogous investigations are prudent in live clinical scenarios. OBJECTIVE: To report a technical note, accuracy, precision analysis of the first in-human deployment of this technology. METHODS: A 78-yr-old female underwent an L4-S1 decompression, pedicle screw, and rod fixation for degenerative spine disease. Six pedicle screws were inserted via AR-HMD (xvision; Augmedics, Chicago, Illinois) navigation. Intraoperative computed tomography was used for navigation registration as well as implant accuracy and precision assessment. Clinical accuracy was graded per the Gertzbein-Robbins (GS) scale by an independent neuroradiologist. Technical precision was analyzed by comparing 3-dimensional (3D) (x, y, z) virtual implant vs real implant position coordinates and reported as linear (mm) and angular (°) deviation. Present data were compared to benchmark cadaveric data. RESULTS: Clinical accuracy (per the GS grading scale) was 100%. Technical precision analysis yielded a mean linear deviation of 2.07 mm (95% CI: 1.62-2.52 mm) and angular deviation of 2.41° (95% CI: 1.57-3.25°). In comparison to prior cadaveric data (99.1%, 2.03 ± 0.99 mm, 1.41 ± 0.61°; GS accuracy 3D linear and angular deviation, respectively), the present results were not significantly different (P > .05). CONCLUSION: The first in human deployment of the single Food and Drug Administration approved AR-HMD stereotactic spine navigation platform demonstrated clinical accuracy and technical precision of inserted hardware comparable to previously acquired cadaveric studies.
STUDY DESIGN: This was a prospective cohort study. OBJECTIVE: The objective of this study was to establish minimal clinically important difference (MCID) and substantial clinical benefit (SCB) thresholds for Patient-Reported Outcomes Measurement Information System (PROMIS) in cervical spine pathology. SUMMARY OF BACKGROUND DATA: PROMIS enables improved psychometric properties with reduced questionnaire burden through computer adaptive testing. Despite studies showing good correlation with "legacy" outcome measures, literature on the clinical significance of changes in PROMIS scores is scarce. MATERIALS AND METHODS: Adult patients undergoing cervical spine surgery at a single institution between 2016 and 2018 were prospectively enrolled. Patients completed questionnaires [Short Form-36 (SF-36), Neck Disability Index (NDI), Visual Analogue Scale Arm/Neck, and PROMIS Pain Interference (PI) and Physical Function (PF)] preoperatively and at 6 months postoperatively. MCID was calculated using distribution-based and SCB using anchor-based methods. The SF-36 Health Transition Item was utilized as an anchor with the cutoff values chosen using receiver operating characteristic curve analysis. RESULTS: There were 139 patients meeting inclusion criteria, with a mean age of 56.4 years and diagnoses of myelopathy (n=36), radiculopathy (n=48) and myeloradiculopathy (n=49). There were significant improvements in PROMIS PF, PROMIS PI, NDI, and SF-36 preoperatively to postoperatively (P<0.001). The test-retest reliability of all tests was excellent (intraclass correlation coefficients=0.87-0.94). PROMIS, SF-36, and NDI were all correlated with the anchor question (|r|=0.34-0.48, P<0.001). MCIDs were 8.5 (NDI), 11.1 (SF-36 Physical Component Score), 9.7 (SF-36 Mental Component Score), 4.9 (PROMIS PI), and 4.5 (PROMIS PF). SCB was 13.0 (NDI), 24.0 (SF-36 Physical Component Score), 11.8 (SF-36 Mental Component Score), 6.9 (PROMIS PI), and 6.8 (PROMIS PF). MCIDs were greater than standard error of measurement for all measures. CONCLUSIONS: We report MCID of 4.9 (PI) and 4.5 (PF) and SCB of 6.9 (PI) and 6.8 (PF). These data support the use of PROMIS computer adaptive tests in cervical spine patients and provide important reference as PROMIS reporting becomes more widespread in the literature.
In the emerging field of robot-assisted spine surgery, the radiographic evaluation of pedicle screw accuracy in clinical application is an area of high interest. This study describes the pedicle screw accuracy of the first 56 consecutive cases in which navigated robotic assistance was used in a private practice clinical setting. A retrospective, Institutional Review Board-exempt review of the first 56 navigated robot-assisted spine surgery cases was performed. Pedicle screw malposition, reposition, and return to operating room (OR) rates were collected. A CT-based Gertzbein and Robbins system (GRS) was used to classify pedicle screw accuracy. In the first 56 robotic cases, 356 total pedicle screws were placed. Eight screws were placed without the robot due to surgeon discretion. Of the 348 pedicle screws inserted by navigated robotic guidance, only 2.6% (9/348) were repositioned, resulting in a 97.4% (339/348) successful screw placement rate. The average age was 64, and 48% were female. Average body mass index was 31 kg/m 2 . Based on the GRS CT-based grading, 97.7% (340/348) were graded A or B, 1.7% (6/348) screws were graded C, and only 0.6% (2/348) of screws were graded D. Two complications, explantation of interbody and vacuum-assisted wound closure, were reported as requiring a return to the OR, but these were not related to robotic guidance or pedicle screws. This study demonstrated a high level of accuracy (97.7%) in the first 56 cases using navigated, robot-assisted surgery based on the GRS. There were two non-screw-related complications requiring return to the operating room.
Three-dimensional (3D) printing is a transformative technology with a potentially wide range of applications in the field of orthopaedic spine surgery. This article aims to review the current applications, limitations, and future developments of 3D printing technology in orthopaedic spine surgery. Current preoperative applications of 3D printing include construction of complex 3D anatomic models for improved visual understanding, preoperative surgical planning, and surgical simulations for resident education. Intraoperatively, 3D printers have been successfully used in surgical guidance systems and in the creation of patient specific implantable devices. Furthermore, 3D printing is revolutionizing the field of regenerative medicine and tissue engineering, allowing construction of biocompatible scaffolds suitable for cell growth and vasculature. Advances in printing technology and evidence of positive clinical outcomes are needed before there is an expansion of 3D printing applied to the clinical setting.
BACKGROUND: Treatment of several spine disorders requires placement of pedicle screws. Detailed 3-dimensional (3D) anatomic information facilitates this process and improves accuracy. OBJECTIVE: To present a workflow for a novel augmented-reality-based surgical navigation (ARSN) system installed in a hybrid operating room for anatomy visualization and instrument guidance during pedicle screw placement. METHODS: The workflow includes surgical exposure, imaging, automatic creation of a 3D model, and pedicle screw path planning for instrument guidance during surgery as well as the actual screw placement, spinal fixation, and wound closure and intraoperative verification of the treatment results. Special focus was given to process integration and minimization of overhead time. Efforts were made to manage staff radiation exposure avoiding the need for lead aprons. Time was kept throughout the procedure and subdivided to reflect key steps. The navigation workflow was validated in a trial with 20 cases requiring pedicle screw placement (13/20 scoliosis). RESULTS: Navigated interventions were performed with a median total time of 379 min per procedure (range 232-548 min for 4-24 implanted pedicle screws).The total procedure time was subdivided into surgical exposure (28%), cone beam computed tomography imaging and 3D segmentation (2%), software planning (6%), navigated surgery for screw placement (17%) and non-navigated instrumentation, wound closure, etc (47%). CONCLUSION: Intraoperative imaging and preparation for surgical navigation totaled 8% of the surgical time. Consequently, ARSN can routinely be used to perform highly accurate surgery potentially decreasing the risk for complications and revision surgery while minimizing radiation exposure to the staff.
ONE potential adverse outcome from surgery is chronic pain. Analysis of predictive and pathologic factors is important to develop rational strategies to prevent this problem. Additionally, the natural history of patients with and without persistent pain after surgery provides an opportunity to improve the understanding of the physiology and psychology of chronic pain.Ideally, studies of chronic postoperative pain should include (1) sufficient preoperative data (assessment of pain, physiologic and psychologic risk factors for chronic pain); (2) detailed descriptions of the operative approaches used (location and length of incisions, handling of nerves and muscles); (3) the intensity and character of acute postoperative pain and its management; and (4) follow-up at intervals to 1 yr or more. In addition, there would be information about postoperative interventions that may influence pain, such as radiation therapy or chemotherapy. At long-term follow-up visits, patient function, physical signs, and symptoms would be evaluated using a standardized algorithm, including quantitative and descriptive pain assessments. We found no studies that contain all of these data.For this review, we specifically sought population data that reflect the incidence of chronic postoperative pain or predictors (medical, physiologic, and psychologic) of chronic pain. We selected five groups of surgeries (limb amputations, breast surgery, gallbladder surgery, lung surgery, and inguinal hernia surgery). These surgeries were selected because the incidence of pain is known to be high, thus improving the probability of detecting predictive factors. They also represent a range of major surgical procedures.We performed a computerized search of the medical literature using the OVID search engine (OVID Technologies, Wolters Kluwer, Amsterdam, The Netherlands). The search was performed on the entire database in January 1999 and covered 1966 through most of 1998. Additional articles published during the review process have also been included. Terms were used in their “exploded” format. The term “pain” was combined with the other appropriate term (e.g., “cholecystectomy”); also the text words associated with the pain syndromes were searched, resulting in more than 1,700 citations. Letters to the editor were not reviewed. Additionally, articles known to the authors but not found in the search were used. If the article contained data about persistent pain (12 weeks or more after surgery), it was considered for inclusion in this review. To calculate the incidence of pain, we used the number of individuals responding at the time the chronic pain data was gathered, and only used data from articles in which the methods section indicated that there was systematic collection of long-term pain information from patients. Studies of fewer than 50 patients were excluded in the incidence data analysis for breast surgery, gallbladder surgery, and lung surgery. Studies of fewer than 100 patients were excluded from the data analysis for inguinal hernia surgery. Amputation studies of 25 subjects or more were included because of the higher incidence of chronic pain.The reported incidence of phantom limb pain varies from 30 to 81% (table 1). Finch et al . 1reported pain in 30% of 57 long-term survivors of amputation for vascular insufficiency. Fisher and Hanspal 2described 93 consecutive amputees referred to a prosthetic rehabilitation clinic; therefore, selection bias may be a factor. The remainder of the studies (table 1) report an incidence of phantom limb pain of more than 50%. Sherman et al. 3noted at least a 78% incidence of phantom limb pain, and perhaps as high as 85%; however, their questionnaire response rate was not high (55%). Stump pain was noted in 66% of patients with phantom pain and in half of those without phantom pain; therefore, the overall stump pain incidence exceeds 60%. Wartan et al . 4reported a 62% incidence of phantom limb pain and 63% for stump pain. Similar to Sherman et al., 66% of patients with phantom limb pain also have stump pain. Smith and Thompson 5reported that pain was more common after amputation for cancer than for trauma, but this study was a chart review (phantom pain noted in medical record), and there were only eight amputations for trauma. No large studies systematically evaluate the incidence of phantom limb pain after trauma, vascular disease, and cancer-related surgeries. The presence of intense preoperative pain in the extremity increases the probability of phantom limb pain (from 33 to 72% at 3 months). 6,7Some early reports 8,9indicated that the incidence of phantom limb pain decreased with prolonged (72 h) preoperative epidural pain control, followed by postoperative epidural pain control. Both studies were small (23 and 24 patients, respectively at 6 months follow-up), and neither was properly randomized. In a subsequent randomized controlled study, 10this observation was not confirmed, but preoperative pain control was limited to 18 h, and the extent and intensity of perioperative blockade was not sufficient to control pain without supplemental systemic opioids.The effect of anesthesia (epidural, spinal, or general) alone has not been studied. Surgical handling of the major nerves is rarely mentioned, so we cannot assess the effect of nerve ligation or clipping versus section alone.Administration of chemotherapy increases the incidence of phantom limb pain. 5Stump pain at 1 week is significantly associated with phantom pain at 1 week, 6and long-term stump pain predicts long-term phantom limb pain. 3There is also a correlation between nonpainful phantom sensations and phantom pain. 4Control of acute postoperative pain with nerve sheath infusion of local anesthetic decreased the incidence of phantom limb pain in one series of 11 patients, 11but a subsequent randomized controlled trial (n = 14 at long term follow-up) 12failed to confirm this finding. Both of these studies are small, and the negative study 12does not have the statistical power to conclude that there is no significant effect. There has also been a negative retrospective report of this technique (n = 21). 13As mentioned previously, data regarding epidural analgesia 8–10as a method to decrease the incidence of phantom limb pain conflict.Most authorities believe that phantom limb sensation and phantom limb pain are central phenomena and explain them using the neuromatrix theory expounded by Melzack. 14,15That is, there is a matrix in the central nervous system for the perception of a body part, and this matrix exists even when the body part does not. Sherman et al . 3emphasized that multiple etiologies may lead to phantom limb pain, based on the inconsistency of therapeutic responses.The incidence of phantom limb pain decreases during the first year after amputation, as does the frequency of painful episodes 7,16; however, about half the individuals with long-term phantom pain report no decrease in the intensity of this pain. 3Phantom limb pain is common after extremity amputation, and documented predictors of this pain include preamputation pain and persistent stump pain (acute and chronic). No conclusive studies have evaluated the effect of acute or subacute stump pain control on long-term stump pain or on long-term phantom limb pain. Also no psychologic studies have evaluated patients before amputation for predictors of chronic pain.Long-term pain after thoracotomy, the postthoracotomy pain syndrome (PTPS), may have an incidence of more than 50%. 17,18Six studies met our inclusion–exclusion criteria (table 2), assessing 878 patients, of whom 417 (47%) had PTPS. Katz et al . 2could not predict PTPS from preoperative psychologic testing (state or trait anxiety, depression inventory) or preoperative pain sensitivity as determined by pressure algometry. This study (n = 23) was the extension of a previous acute pain study; it therefore lacks statistical power and may be subject to selection bias. Perttunen et al . 19noted the presence of preoperative pain in 17% of their patients but did not analyze it as an independent risk factor.Several recent case series report that video-assisted thoracoscopic lung surgery (VATS) is associated with a low incidence of PTPS. Walker et al . 20reported only 1 case of 83 (1.2%), and Mouroux et al . 21noted a 3% incidence of PTPS, but neither group reports systematically looking for PTPS. In a large retrospective survey, Landreneau et al . 22(table 2) noted a lower incidence of pain in patients who had VATS compared with those who underwent lateral thoracotomy (30 vs. 44%); however, pain medication requirements did not differ. The difference in pain incidence was statistically significant only during the first year after surgery. In a small (n = 30), nonrandomized prospective study, Furrer et al. 23found a 36% incidence of PTPS in patients undergoing VATS wedge resection, and a 33% incidence of PTPS in a matched group of patients undergoing lobectomy by a classic posterolateral thoracotomy. However, the results are confounded because the thoracotomy group received thoracic epidural analgesia with local anesthetic and opioid, whereas the thoracoscopic group received intravenous patient-controlled opioids. Nomori et al. 24retrospectively and Benedetti et al. 25prospectively (case series) reported a decreased severity of chronic pain after anterolateral thoracotomy when compared with classic posterolateral thoracotomy (mean visual analog scale [VAS] score, 6 of 100 vs. 21 of 100). Both studies were small (24 and 42 patients), and chronic postoperative pain was not a primary outcome parameter. In descriptions of the surgical technique for posterolateral thoracotomy, details about whether a rib was resected or about how the intercostal nerves were handled were missing from most reports.A recent report by Obata et al . 26(table 2) found a significant effect of intraoperative plus postoperative epidural analgesia when compared with just postoperative epidural analgesia (decreasing the incidence of pain at 6 months from 67% to 33%). This is a prospective, randomized, single-blind study.The intensity of acute postoperative pain is a statistically significant predictor 18,27of PTPS (36 vs. 56% PTPS for minor vs. moderate to severe acute pain). As mentioned previously herein, the combination of intraoperative plus postoperative epidural analgesia with local anesthetic was associated with a decreased incidence of pain at 6 months. An attempt at preemptive analgesia 28had not improved analgesia on long-term follow-up. 18Another small study found that the type of postoperative analgesia affected the incidence of pain at 12 weeks (less pain with epidural analgesia or intercostal nerve cryoablation), but data of only 33 subjects divided among four treatment regimens were reported. 29Benedetti et al. 25,30showed that intercostal nerve dysfunction (loss of the superficial abdominal reflex) is associated with more acute, subacute, and chronic (3 months) pain. Of 23 patients with intact reflexes on postoperative day 1, none had pain at 2 to 3 months, whereas 50% of individuals with persistent loss of the reflex still had pain at this time.The etiology of PTPS may depend on nerve damage because it is more severe after chest wall resection, 31–33and the loss of superficial abdominal reflexes is associated with an increased probability of PTPS. 25,30Another contributing factor is recurrence of tumor. 31For thoracoscopic surgeries and posterolateral thoracotomy, Landreneau et al . 22noted a 30% decrease in the incidence in pain reported by patients more than 12 months after surgery compared with those 3–12 months after surgery. The prospective study by Perttunen et al . 19noted the incidence of pain at 3, 6, and 12 months to be decreasing (80, 75, and 61%, respectively). Of patients with long-term pain after thoracotomy, up to half describe their pain as moderate or severe, 18and 66% are prescribed analgesics for the pain. 27Postthoracotomy pain syndrome is common. The predictors of this syndrome (when tumor recurrence is excluded) include the extent of acute postoperative pain and intercostal nerve dysfunction (which may link more acute pain and persistent pain). One prospective, randomized controlled study 28found that the combination of intraoperative plus postoperative thoracic epidural analgesia decreases the incidence of PTPS at 6 months.Table 3summarizes various studies of pain after breast surgery. Women who undergo breast surgery experience chest wall, breast, or scar pain (range, 11–57%), phantom breast pain (13–24%), and arm and shoulder pain (12–51%). The incidence of pain in one or more of these sites is close to 50% 1 yr after breast surgery for cancer. The postmastectomy pain syndrome (PMPS) has recently been reviewed, 34with some disagreement about which pains to include in this syndrome. Husted et al . 35documented that, of 163 women who had undergone mastectomy with axillary node dissection, 45% reported cicatrix pain, 45% reported arm, neck, or shoulder pain, and only 21% were symptom free (symptoms included pain, paresthesia, lymphedema, and impaired shoulder function) 1–5 yr after surgery. Moderate to severe pain was reported by 16 patients (10%). Krøner et al . 36reported a significant relation between preoperative breast pain and postoperative phantom breast pain in a prospective study of 120 patients. In contrast, Tasmuth et al., 37,38in a prospective study of 93 patients, did not find the presence of preoperative pain to be a predictive but only patients had pain before surgery. depression and were more common in patients in whom chronic pain when compared with those in whom chronic pain did not statistical was not type of surgery may the incidence of pain. Tasmuth et al. that chronic pain was more common after breast surgery than after surgery in their large retrospective study, but did not confirm this in prospective et al., their questionnaire of women who had undergone breast surgery, found that mastectomy combined with of a breast a higher incidence of pain than did mastectomy alone et al . in the of the nerve at 3 months after axillary node in of women in whom the nerve was and in of women in whom it was et al . that axillary increased the of arm and of psychologic et al . found the extent of axillary with the incidence of arm pain and et al . a analysis of factors that the patient to chronic pain after breast cancer surgery. The extent of acute postoperative pain and the number of of postoperative analgesics were the predictors of persistent pain in the breast and the Additionally, postoperative radiation therapy was a risk factor for chronic pain in the breast and the et al . that axillary radiation therapy increased the incidence of arm pain and et al . Krøner et al . a relation between phantom breast sensations and radiation but their studies were and only sought a of of the pain after breast surgery has been to nerve whether from surgery or and that and sensation decreased nerve in the long-term in of women undergoing and of women undergoing but pain data were not reported. was in the of the nerve in of women undergoing axillary In in of women with these was associated with a higher incidence of arm pain and arm symptoms and were more common after breast surgery with axillary node The among pain, and preoperative psychologic have not been among women undergoing breast natural history of pain during the first year after surgery has not been In one study, the incidence of pain in the breast decreased from to from 3 weeks to 1 yr after surgery, whereas the incidence of decreased from to study, the incidence of arm pain decreased from 3 to months after surgery to respectively). incidence of phantom breast pain is from 3 weeks to 6 pain is common after breast surgery, and the major predictive factors are the extent of acute postoperative pain, the presence of pain before surgery, the type of surgery, nerve radiation and preoperative or abdominal pain after is common (range, but than the preoperative incidence of pain The syndrome has a number of in to abdominal pain, and may not have a factors include postoperative pain; pain by postoperative of pain by a other than gallbladder pain by a and other preoperative factors that the patient to an is a predictor of long-term pain and symptoms after other risk factors include symptoms before surgery. history of classic gallbladder symptoms is associated with risk of chronic pain and surgical to no significant difference in overall et al., a randomized controlled trial (n = noted that patients randomized to had more to whereas patients randomized to had more of scar pain and did not report pain incidence There to be no difference in chronic abdominal pain when is compared with et al . a 30% incidence of abdominal pain more than 1 yr after but this incidence did not include 16 patients with pain. et al . significantly more pain after than after surgery and that there was more intercostal nerve damage from the et al., a prospective study of 100 patients who underwent noted that pain at 6 weeks was a predictor of persistent pain and other symptoms at 1 yr and We found no studies that evaluated acute postoperative pain as a predictor of chronic are multiple etiologies of the including of and scar pain. The of factor has not been the frequency of persistent symptoms after patient after the is high, with authors that may to patient most patients with abdominal pain and believe that without surgery and that their improve after symptoms are common after as is chronic abdominal pain. factors include psychologic preoperative symptoms and pain at 6 weeks after surgery. studies of the syndrome have not scar pain and pain from other of chronic pain and number of studies have evaluated chronic pain after surgery, with the reported incidence of chronic pain from to (table The overall incidence from these studies is of pain was a primary outcome in only four these studies report a In a prospective study of surgery for a hernia had a higher incidence of moderate to severe pain at 12 months than did surgery for a primary for have a higher pain incidence at 6 months than those who are for by of vs. 1 of have had pain for a of time before data are about whether the surgical the incidence of chronic pain. et al., a prospective randomized controlled study that evaluated recurrence found a lower incidence of chronic pain after a when compared with an The study found a significantly lower incidence of pain at 12 months after a compared with an et al. no difference in the incidence of chronic pain in their prospective randomized controlled study that compared an to a and no difference in the incidence of pain in their case with and a incidence of chronic pain. of the studies that including pain, were more common early in their experience with hernia a prospective study, et al. not find statistically significant in chronic pain after or in a prospective analysis of et al., no significant in chronic pain between and in primary hernia surgery. the experience of the or the of is a factor in chronic pain or recurrence has been incidence of chronic pain in case series data from hernia is reports with higher of chronic pain from are no prospective studies of this extent of pain at 1 and weeks after surgery is a predictive factor pain at 1 length of type of the incidence of chronic pain. relation between postoperative dysfunction and chronic pain the that nerve damage is a pathologic factor. authors the pain is of the of the et al . the incidence of moderate to severe pain decreased from at weeks to at 1 Moderate to severe pain at 1 and weeks was the predictor of pain at 1 pain after hernia surgery is not but it to be common than chronic pain after the surgeries previously hernia surgery is a large number of individuals are affected by chronic pain. dysfunction has been to be a as has the intensity of early postoperative pain. The of acute pain therapy on the incidence of chronic pain is patient with surgical results is reported to be high, studies reported that chronic pain is common after these and this has been in a recent review. pain is to in of and and the of chronic pain after surgery should be is also there is significant in the incidence of chronic pain among these surgical for inguinal hernia and thoracic surgery). We believe that our review has been but the of search our search did not all articles known to the authors that to the or incidence of chronic pain after the selected surgeries. for this include in not included in the at the time of (e.g., et al . and or “pain” not as a or used in the or (e.g., et al. As a we are not that we all articles that contain data to this a number of risk factors for prolonged pain after surgery and these factors (1) preoperative (2) intraoperative and (3) postoperative factors (table pain is a predictor of chronic pain for pain, breast pain, abdominal pain and symptoms after of these the of the preoperative pain that chronic pain to be pain of 1 or more in is a risk factor for persistent pain after has not been evaluated in the other surgeries has also been found to predict outcome after surgery. damage is an intraoperative factor that to chronic postoperative pain. undergoing thoracotomy are to have intercostal nerve dysfunction and to have PTPS. breast surgery, is associated with damage of that and to the nerve are associated with a lower incidence of pain. nerve damage does not pain because the incidence of decreased sensation was higher than the incidence of pain in the of the nerve after axillary node Benedetti et al. chronic pain in only 50% of individuals with intercostal nerve dysfunction after thoracotomy. nerve dysfunction to be associated with chronic pain. most predictive postoperative factor is the severity of acute postoperative pain after breast surgery, surgery, hernia radiation therapy increases the risk of chronic pain after breast surgery, chemotherapy increases the risk of phantom limb pain. acute pain chronic pain has been a that and factors and the severity of acute pain as factors in the of chronic pain. we believe that from nerve increases acute pain and early months) chronic pain. in the nervous system associated with acute pain, with the that pain should be considered a of the nervous not a symptom of some other If persistent pain after surgery results from may be be Obata et al . this in thoracotomy patients with intraoperative plus postoperative epidural but other studies of preemptive analgesia are from factors are also predictors of chronic pain. Of the surgical we reviewed, the only psychologic predictor has been The questionnaire for psychologic a that with depression are preoperative predictors of chronic pain after surgery. et al . when to predict chronic pain in acute pain patients. They that is not associated with an increased risk of of chronic low pain, but may reflect or in that are to chronic pain. The of et al. with the psychologic in chronic pain is common after amputation, inguinal hernia surgery, breast surgery, gallbladder surgery, and lung surgery, and this is also in recent review. of these data may be as chronic pain as one of acute postoperative pain is a predictor of chronic pain. studies should the factors of in the from acute to chronic pain. may in more and more rational early We that, in some patients, the type of nerve may explain the in acute pain and the chronic pain, but the extent of pain be by other psychologic and physiologic factors that pain
Examining trends and geographic variations in clinical care offers insights into changes in clinical decision making. We summarized data on spine surgical rates, trends, and variations in the United States to highlight areas of professional uncertainty and questions for future research. The United States has the highest rate of spine surgery in the world, but spine surgery shows wider geographic variations than most other procedures. For example, Medicare data for 2001 showed sixfold variations in spine surgery rates among United States cities, and 10-fold variations in spine fusion rates. United States spine surgery rates rose 55% in the 1980s. In the 1990s, studies of surgical rates became more difficult because 20% of discectomies shifted to an out-patient setting. Extrapolations from states with ambulatory surgery data suggest overall lumbar surgery rates continued to rise throughout the 1990s. The most rapid increase was for spinal fusion, which tripled during the 1990s and accounted for an increasing proportion of all spine procedures. Some increases coincided with the introduction of new surgical implants. Despite new technologies, rates of repeat surgery after fusion were no lower than the rates after decompression alone. As new technology for spine surgery is introduced at an accelerating pace, we anticipate substantial changes in surgery patterns. Analysis of population-based data may be useful for surveillance of changes and their impacts.
STUDY DESIGN: Retrospective cohort study using a hospital discharge registry of all nonfederal acute care hospitals in Washington state. OBJECTIVES: To determine the cumulative incidence of reoperation following lumbar surgery for degenerative disease and, for specific diagnoses, to compare the frequency of reoperation following fusion with that following decompression alone. SUMMARY OF BACKGROUND DATA: Repeat lumbar spine operations are generally undesirable, implying persistent symptoms, progression of degenerative changes, or treatment complications. Compared to decompression alone, spine fusion is commonly viewed as a stabilizing treatment that may reduce the need for additional surgery. However, indications for fusion surgery in degenerative spine disorders remain controversial, and the effects of fusion on reoperation rates are unclear. METHODS: Adults who underwent inpatient lumbar surgery for degenerative spine disorders in 1990-1993 (n = 24,882) were identified from International Classification of Diseases ninth Revision, Clinical Modification codes and then categorized as having either a lumbar decompression surgery or lumbar fusion surgery. We then compared the subsequent incidence of lumbar spine surgery between these groups. RESULTS: Patients who had surgery in 1990-93 had a 19% cumulative incidence of reoperation during the subsequent 11 years. Patients with spondylolisthesis had a lower cumulative incidence of reoperation after fusion surgery than after decompression alone (17.1% vs. 28.0%, P = 0.002). For other diagnoses combined, the cumulative incidence of reoperation was higher following fusion than following decompression alone (21.5% vs. 18.8%, P = 0.008). After fusion surgery, 62.5% of reoperations were associated with a diagnosis suggesting device complication or pseudarthrosis. CONCLUSION: Patients should be informed that the likelihood of reoperation following a lumbar spine operation is substantial. For spondylolisthesis, reoperation is less likely following fusion than following decompression alone. For other degenerative spine conditions, the cumulative incidence of reoperation is higher or unimproved after a fusion procedure compared to decompression alone.
BACKGROUND: Validated health-related quality-of-life measures have become important standards in the evaluation of the outcomes of lumbar spine surgery. However, there are few well-defined criteria for clinical success based on these measures. The minimum clinically important difference is an important demarcation, but it could be considered a floor value rather than a goal in defining clinical success. Therefore, we sought to define thresholds of substantial clinical benefit for commonly used health-related quality-of-life measures following lumbar spine arthrodesis. METHODS: Prospectively collected preoperative and one-year postoperative health-related quality-of-life measures from 357 patients who were managed with lumbar spine arthrodesis for the treatment of degenerative conditions were identified. Candidate substantial clinical benefit thresholds for the Short Form-36 physical component score, Oswestry Disability Index, and back and leg pain numeric rating scales were identified with use of receiver operating characteristic curve analysis. Receiver operating characteristic curves were used to discriminate between patients who reported being "much better" or "about the same" with use of the validated Short Form-36 health transition item and between those who reported being "mostly satisfied" or "unsure" with use of a nonvalidated but more surgery-specific satisfaction-with-results survey. For each health-related quality-of-life measure, three response parameters were used: net change, percent change, and raw score at the time of the one-year follow-up. RESULTS: Substantial clinical benefit thresholds for the Short Form-36 physical component score were a 6.2-point net improvement, a 19.4% improvement, or a final raw score of > or = 35.1 points. Substantial clinical benefit thresholds for the Oswestry Disability Index were an 18.8-point net improvement, a 36.8% improvement, or a final raw score of < 31.3 points. Substantial clinical benefit thresholds for the back pain and leg pain numeric rating scales were a 2.5-point net improvement or a final raw score of < 3.5 points. Substantial clinical benefit thresholds for percent change were 41.4% for the back pain numeric rating scale and 38.8% for the leg pain numeric rating scale. CONCLUSIONS: We believe that thresholds of substantial clinical benefit for commonly used health-related quality-of-life measures following lumbar spine arthrodesis are important as they describe a magnitude of change that the patient recognizes as a major improvement.
STUDY DESIGN: Retrospective review of a large series of patients who underwent spinal surgery at a single institution during a 10-year period. OBJECTIVES: To further clarify the frequency of incidental durotomy during spine surgery, its treatment, associated complications, and results of long-term clinical follow-up. SUMMARY OF BACKGROUND DATA: Incidental durotomy is a relatively common occurrence during spinal surgery. There remains significant concern about it despite reports of good associated clinical outcomes. There have been few large clinical series on the subject. METHODS: A retrospective review was conducted of clinical and surgical records and radiographic data for consecutive patients who underwent spinal surgery performed by the two senior surgeons from January 1989 through December 1998. RESULTS: A total of 2144 patients were reviewed, and 74 were found to have dural tears occurring during or before surgery. Incidental durotomy occurred at the time of surgery in 66 patients (3.1% overall incidence). Incidence varied according to the specific procedure performed but was highest in the group that underwent revision surgery. The incidence of clinically significant durotomies occurring during surgery but not identified at the time was 0.28%. All dural tears that occurred during surgery and were recognized (60 of 66) were repaired primarily. Pseudomeningoceles developed in five of the remaining six patients. All six patients had subsequent surgical repair of dural defects because of failure of conservative therapy. A mean follow-up of 22.4 months was available and showed good long-term clinical results for all patients. CONCLUSIONS: Incidental durotomy, if recognized and treated appropriately, does not lead to long-term sequelae.
In 2002, an author group selected and sponsored by the Joint Section on Spine and Peripheral Nerves of the American Association of Neurological Surgeons and Congress of Neurological Surgeons published the first evidence-based guidelines for the management of patients with acute cervical spinal cord injuries (SCIs).1-23 In the spirit of keeping up with changes in information available in the medical literature that might provide more contemporary and more robust medical evidence, another author group was recruited to revise and update the guidelines. The review process has been completed and is published and can be once again found as a supplement to Neurosurgery. The purpose of this article is to provide an overview of the changes in the recommendations as a result of new evidence or broadened scope. CHANGES IN METHODOLOGY In accordance with the established practice of guideline development within organized neurosurgery, a thorough review of the medical literature was undertaken for each subject chosen for evaluation. Although literature outside the English language was excluded, a sample of non-English abstracts that could be found in the database of the National Library of Medicine failed to reveal any data significantly different from what we found in the English literature. Each chapter of recommendations contained in the new guidelines uses standard search techniques fully described in each chapter. After articles appropriate to each review question were identified, a rigorous critical evaluation was undertaken to establish the strength (quality) of the evidence and the level (certainty) of the recommendations. As in previous guidelines, published evidence was divided into Class I (well-designed and -executed randomized controlled trials), Class II (comparative studies, including randomized controlled trials with significant flaws, nonrandomized cohort studies, or case-control studies), and Class III (case series and expert opinion). Different from previous recommendations, the levels that used to be called standards, guidelines, and options are now referred to as Level I, Level II, and Level III, bringing them more in line with other neurosurgical and medical specialty paradigms and allowing the use of the term guidelines to denote the broader scope of the overall recommendations.24 Our author group universally felt that further stratification of guidelines into additional subsets (1a, 1b, 1c, 2a, 2b, 2c, etc)25 would not denote improved certainty or strength but instead would undermine consensus building and promote confusion among the readership. NOTABLE EXCLUSIONS FROM THE GUIDELINES Topical areas not included in the current guidelines pertain to the timing of surgery and use of hypothermia. The published evidence for these clinical strategies is so sparse that recommendations cannot be made with any degree of confidence pending further study. A single prospective study on surgical timing has subsequently been published since completion of our SCI guidelines review. Although designed as a prospective, nonrandomized comparative study (Class II), methodological flaws downgrade it to Class III evidence, rendering it unhelpful for establishing quality and certainty in the case of acute surgical intervention in SCI.26 Systemic hypothermia has been studied in animal models of SCI but only anecdotally in humans by way of a single Class II study also published after the current guidelines went to press. Again, in this instance, the evidence is early and cannot support a practice recommendation.27 The use of intraoperative somatosensory evoked potentials in the setting of trauma as a warning of SCI has not been addressed in the current guidelines. Those studies that our author group was able to find were carried out in nonacute (elective) spinal surgical situations. Although we felt that inferences might be made to acute SCI surgery, our supervising Joint Guidelines Committee of the American Association of Neurological Surgeons and Congress of Neurological Surgeons preferred to minimize such extrapolations. Hence, recommendations with respect to intraoperative electrophysiological monitoring will be made under a different (nontraumatic) guidelines initiative. Functional magnetic resonance imaging may potentially contribute to SCI research, but to date, there are no clinical studies that establish its usefulness in human SCI. Thus, it has been excluded from the current guidelines.28 Similarly, there are no recommendations on the use of drugs,29 biologicals,30 or devices31 aimed at neural regeneration of the spinal cord because of the absence of clinical evidence. It is our hope that such evidence will be forthcoming in time for the next SCI guidelines review. SCOPE OF THE REVISED GUIDELINES In this 2013 iteration of the cervical SCIs guidelines, the scope has been broadened, as have the recommendations. In 2002, the guidelines featured 76 recommendations in contrast to 112 recommendations in the present version. Among the new guidelines are 19 Level I recommendations supported by Class I medical evidence. These include assessment of functional outcomes (1); assessment of pain after SCI (1); radiographic assessment (1); pharmacology (2); diagnosis of atlanto-occipital dislocation (1); cervical subaxial injury classification schemes (2); pediatric spinal injuries (1); vertebral artery injuries (1); and venous thromboembolism (1). In addition, there are 11 Level II recommendations, based on Class II evidence, with the remaining 77 recommendations qualifying as Level III recommendations from a variety of Class III medical evidence. The Table highlights these differences between the 2 SCI guidelines processes (used with permission from the published guidelines).32TABLE-a: Comparison of Cervical Spine and Spinal Cord Injury Guidelines Recommendations Between 2 Iterations Where Differences in Recommendations Have Occurred (All Other Recommendations Remain as Previously Stated) a 32TABLE-b: Comparison of Cervical Spine and Spinal Cord Injury Guidelines Recommendations Between 2 Iterations Where Differences in Recommendations Have Occurred (All Other Recommendations Remain as Previously Stated) a 32TABLE-c: Comparison of Cervical Spine and Spinal Cord Injury Guidelines Recommendations Between 2 Iterations Where Differences in Recommendations Have Occurred (All Other Recommendations Remain as Previously Stated) a 32TABLE-d: Comparison of Cervical Spine and Spinal Cord Injury Guidelines Recommendations Between 2 Iterations Where Differences in Recommendations Have Occurred (All Other Recommendations Remain as Previously Stated) a 32TABLE-e: Comparison of Cervical Spine and Spinal Cord Injury Guidelines Recommendations Between 2 Iterations Where Differences in Recommendations Have Occurred (All Other Recommendations Remain as Previously Stated) a 32TABLE-f: Comparison of Cervical Spine and Spinal Cord Injury Guidelines Recommendations Between 2 Iterations Where Differences in Recommendations Have Occurred (All Other Recommendations Remain as Previously Stated) a 32TABLE: g Comparison of Cervical Spine and Spinal Cord Injury Guidelines Recommendations Between 2 Iterations Where Differences in Recommendations Have Occurred (All Other Recommendations Remain as Previously Stated) a 32TABLE: h Comparison of Cervical Spine and Spinal Cord Injury Guidelines Recommendations Between 2 Iterations Where Differences in Recommendations Have Occurred (All Other Recommendations Remain as Previously Stated) a 32The most contentious of the present recommendations likely pertains to the use of methylprednisolone in acute SCI and therefore deserves special comment. Methylprednisolone has been used for decades as a standard of care to improve neurological and functional outcome in SCI; however, careful examination, particularly of randomized clinical trials expected to produce Class I data,33-35 reveals many methodological flaws in study design and data analysis that refute the conclusions of the authors.36-38 As these limitations have come to light, there has also been a change in the perception of frontline surgeons treating SCI with respect to the necessity of steroids at all.39-43 In the case of the present guidelines, our author group downgraded them from Class I to Class III because the primary (a priori) outcome measures were all negative. Any positive results reported from either National Acute Spinal Cord Injury Study (NASCIS) II or NASCIS III came from post hoc analysis rather than being preplanned. In a randomized clinical trial, comparison of data defined by protocol (ie, before data are accrued) is considered Class I evidence, including both primary and secondary outcomes. All other queries within the data set are Class III, whether they are published at the time of initial analysis or 10 years later. Class II is reserved for a priori comparisons within a prospective study in which the study population is nonrandomized but still comparative (eg, cohort studies, case-control studies, or before-and-after studies). This is fundamentally important and explains why retrospective mining of a prospective database still yields Class III evidence (unless in the format of a case-control study). Class of evidence pertains to how the research question was asked (study design). It does not pertain to how the data were accrued. The underlying tenet is that retrospective examination of prospective data is still a “fishing expedition” or essentially a retrospective exercise unless clearly stated as part of the prospective research question(s). Outside of a priori analyses, any number of post hoc comparisons can be made within a data set (retrospective or prospective) until an interesting result is found. In a perfect world, authors should report how many post hoc comparisons they make and apply a correction to their statistical testing (eg, Bonferroni) before reporting claims of positive results. However, in reality, we know that this rarely happens, including in the case of the NASCIS studies. SUMMARY The 2013 update on the “Guidelines for the Management of Acute Cervical Spine and Spinal Cord Injuries” is meant to help the practicing neurosurgeon in his or her efforts to provide up-to-date, evidence-based care to patients with acute SCIs. They are based on a formal critical evaluation of the evidence, with a well-developed relationship between the strength of the evidence and the level of recommendations. This time-consuming and extensive process produces the best estimate of scientific foundation for current SCI care. For related video content, please access the Supplemental Digital Content: http://www.youtube.com/watch?v=KB1NBEDkw9c Disclosures Funding was provided by the Joint Section on Spine and Peripheral Nerves of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons for author travel and accommodation. The authors have no personal financial or institutional interest in any of the drugs, materials, or devices described in this article.
In Brief Study Design. Sequential cross-sectional study. Objectives. To quantify patterns of outpatient lumbar spine surgery. Summary of Background Data. Outpatient lumbar spine surgery patterns are undocumented. Methods. We used CPT-4 and ICD-9-CM diagnosis/procedure codes to identify lumbar spine operations in 20+ year olds. We combined sample volume estimates from the National Hospital Discharge Survey (NHDS), the National Survey of Ambulatory Surgery (NSAS), and the Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) with complete case counts from HCUP's State Inpatient Databases (SIDs) and State Ambulatory Surgery Databases (SASDs) for four geographically diverse states. We excluded pregnant patients and those with vertebral fractures, cancer, trauma, or infection. We calculated age- and sex-adjusted rates. Results. Ambulatory cases comprised 4% to 13% of procedures performed from 1994 to 1996 (NHDS/NSAS data), versus 9% to 17% for 1997 to 2000 (SID/SASD data). Discectomies comprised 70% to 90% of outpatient cases. Conversely, proportions of discectomies performed on outpatients rose from 4% in 1994 to 26% in 2000. Outpatient fusions and laminectomies were uncommon. NIS data indicate that nationwide inpatient surgery rates were stable (159 cases/100,000 in 1994 vs. 162/100,000 in 2000). However, combined data from all sources suggest that inpatient and outpatient rates rose from 164 cases/100,000 in 1994 to 201/100,000 in 2000. Conclusions. While inpatient lumbar surgery rates remained relatively stable for 1994 to 2000, outpatient surgery increased over time. While inpatient lumbar spine surgery rates were stable from 1994 to 2000, outpatient surgery rates rose over time. Discectomies accounted for the vast majority of outpatient procedures. Future research should examine more recent trends as well as the clinical, cost, and other implications of growing use of the outpatient approach.