Application of Wearable Sensors Technology for Lumbar Spine Kinematic Measurements during Daily Activities following Microdiscectomy Due to Severe Sciatica.

BACKGROUND: The recurrence rate of lumbar spine microdiscectomies (rLSMs) is estimated to be 5-15%. Lumbar spine flexion (LSF) of more than 10° is mentioned as the most harmful load to the intervertebral disc that could lead to recurrence during the first six postoperative weeks. The purpose of this study is to quantify LSFs, following LSM, at the period of six weeks postoperatively. METHODS: LSFs were recorded during the daily activities of 69 subjects for 24 h twice per week, using Inertial Measurement Units (IMU). RESULTS: The mean number of more than 10 degrees of LSFs per hour were: 41.3/h during the 1st postoperative week (P.W.) (29.9% healthy subjects-H.S.), 2nd P.W. 60.1/h (43.5% H.S.), 3rd P.W. 74.2/h (53.7% H.S.), 4th P.W. 82.9/h (60% H.S.), 5th P.W. 97.3/h (70.4% H.S.) and 6th P.W. 105.5/h (76.4% H.S.). CONCLUSIONS: LSFs constitute important risk factors for rLDH. Our study records the lumbar spine kinematic pattern of such patients for the first time during their daily activities. Patients' data report less sagittal plane movements than healthy subjects. In vitro studies should be carried out, replicating our results to identify if such a kinematic pattern could cause rLDH. Furthermore, IMU biofeedback capabilities could protect patients from such harmful movements.

A new classification for coronal malalignment in adult spinal deformity: a validation and the role of lateral bending radiographs.

PURPOSE: Coronal malalignment (CM) causes pain, impairment of function and cosmetic problems for adult spinal deformity (ASD) patients in addition to sagittal malalignment. Certain types of CM are at risk of insufficient re-alignment after correction. However, CM has received minimal attention in the literature compared to sagittal malalignment. The purpose was to establish reliability for our recently published classification system of CM in ASD among spine surgeons. METHODS: Fifteen readers were assigned 28 cases for classification, who represented CM with reference to their full-length standing anteroposterior and lateral radiographs. The assignment was repeated 2 weeks later, then a third assignment was done with reference to additional side bending radiographs (SBRs). Intra-, inter-rater reliability and contribution of SBRs were determined. RESULTS: Intra-rater reliability was calculated as 0.95, 0.86 and 0.73 for main curve types, subtypes with first modifier, and subtypes with two modifiers respectively. Inter-rater reliability averaged 0.91, 0.75 and 0.52. No differences in intra-rater reliability were shown between the four expert elaborators of the classification and other readers. SBRs helped to increase the concordance rate of second modifiers or changed to appropriate grading in cases graded type A in first modifier. CONCLUSIONS: Adequate intra- and inter-rater reliability was shown in the Obeid-CM classification with reference to full spine anteroposterior and lateral radiographs. While side bending radiographs did not improve the classification reliability, they contributed to a better understanding in certain cases. Surgeons should consider both the sagittal and coronal planes, and this system may allow better surgical decision making for CM.

Methodology of surface electromyography in gait analysis: review of the literature.

Gait analysis is a significant diagnostic procedure for the clinicians who manage musculoskeletal disorders. Surface electromyography (sEMG) combined with kinematic and kinetic data is a useful tool for decision making of the appropriate method needed to treat such patients. sEMG has been used for decades to evaluate neuromuscular responses during a range of activities and develop rehabilitation protocols. The sEMG methodology followed by researchers assessed the issues of noise control, wave frequency, cross talk, low signal reception, muscle co-contraction, electrode placement protocol and procedure as well as EMG signal timing, intensity and normalisation so as to collect accurate, adequate and meaningful data. Further research should be done to provide more information related to the muscle activity recorded by sEMG and the force produced by the corresponding muscle during gait analysis.

Spinal Surgery Complications and Failures in Patients with Parkinsons Disease.

Parkinson's disease is a degenerative disorder of the central nervous system affecting the substantia nigra in the midbrain. It accounts for 1.5% of the population in Europe over 60 years of age. Recent advances in the medical treatment of Parkinson's disease have improved the quality of life and life expectancy of the patients. However, it remains a debilitating disease. Spinal disorders are frequent in these patients, and as the population ages, more patients with Parkinson's disease are expected to require spinal surgery. Spinal surgery in patients with Parkinson's disease has been associated with an exceptionally high rate of complications; failures and reoperations are common, and patient outcomes are dismal.

Apex of deformity for three-column osteotomy. Does it matter in the occurrence of complications?

BACKGROUND: Posterior vertebral column resection (PVCR) is a challenging but effective technique for the correction of complex spinal deformity. However, it has a high complication rate and carries a substantial risk for neurologic injury. PURPOSE: The aim was to test whether the apex of the deformity influences the clinical outcomes and complications in patients undergoing PVCR. STUDY DESIGN: A historical cohort was recruited from a single center and evaluated preoperatively, postoperatively, and at final follow-up. PATIENT SAMPLE: Ninety-eight hyperkyphotic patients undergoing PVCR were included. Inclusion criteria consisted of kyphoscoliosis and hyperkyphosis surgically treated with PVCR as a primary or revision procedure. OUTCOME MEASURES: The outcome measures included a number of neurologic complications. METHODS: Receiver operator characteristic (ROC) curve analysis and Youden index (J) were used to estimate the optimum cut-off to predict neurologic complications for each potential risk factor. In three ROC analyses, we included separately body mass index (BMI), kyphosis degree, and age as independent variables and neurologic complications as the dependent variable. Logistic regression was used to estimate the odds ratios (ORs) and construct 95% confidence intervals (CIs). RESULTS: Among the 98 patients, the etiologies were: post infectious (50), congenital (31), and others (17). The averages were: age 14±6.5 years, BMI 20±10 kg/m(2), American Society of Anesthesiologists 3±0.7, forced vital capacity 76±23%, fusion levels 10±3, estimated blood loss 1,319±720 mL, surgical time 375±101 minutes, and preoperative localized kyphosis 104±30°. Thirty-three patients had abnormal preoperative neurologic status. Major complications occurred in 46 patients (neurologic in 25). The apex of kyphosis was proximal thoracic T1-T5 (five patients), thoracic (TH) T6-T9 (17 patients), thoracolumbar T10-L2 (55 patients), and lumbar L3-S1 (nine patients). The level of apex and BMI were independent risk factors for neurologic complications: TH apex (OR: 101.30, 95% CI: 1.420-infinite; p=.037); BMI (OR: 1.92, 95% CI: 1.110-infinite; p=.026). CONCLUSIONS: Posterior vertebral column resection for severe spine deformity is technically demanding and carries a substantial risk. The apex is a variable that influences the occurrence of neurologic complications, and the presence of a TH apex in particular could be a preoperative risk factor for neurologic complications.

Preoperative halo-gravity traction for severe spinal deformities at an SRS-GOP site in West Africa: protocols, complications, and results.

STUDY DESIGN: Retrospective analysis of a prospectively collected single-center database. OBJECTIVE: We describe a modified halo-gravity traction (HGT) protocol for patients with severe spinal deformities in West Africa, and assess the clinical and radiographic outcomes. SUMMARY OF BACKGROUND DATA: Three-column osteotomies are frequently used in the correction of severe spinal deformities; however, these can be associated with high complication rates and significant risk for neurological injury. Preoperative traction is one modality used to obtain a partial correction prior to definitive fusion. Low numbers and variability of traction protocols, however, have limited previous reports of sustained HGT. METHODS: All patients who underwent HGT in Ghana from April 2012 to August 2013 were reviewed. HGT was started at 20% body weight and increased by 10% per week until 50% body weight was reached by 4 weeks or thereafter as tolerated. Demographic variables, operative data, radiographic parameters, and health-related quality of life scores were collected. A deformity reduction index was calculated at each time point by summing the scoliosis and abnormal kyphosis for each patient and reported as a percentage of the preoperative deformity. RESULTS: Twenty-nine patients underwent HGT for an average 107 days prior to definitive posterior spinal fusion (24 patients) or placement of growing rods (5 patients). The major curve improved from an average 131° to 90° (31%) after HGT, and to an average 57° (56%) postoperatively. Pure kyphotic curves were rigid (flexibility 22% after traction), with a correction index of 3.88, which is similar to historical controls. Deformity correction with HGT plateaued at 63 days. Overall Scoliosis Research Society-22 questionnaire scores improved significantly pretraction versus postoperatively, but there was no change after traction versus before traction. There were 11 pin tract infections, with no neurological complications. CONCLUSION: HGT is a safe method to partially correct severe spinal deformities prior to a definitive procedure, and may reduce the need for higher risk 3-column osteotomies. Importantly, kyphosis secondary to infection with spontaneous apical ankylosis is relatively resistant to HGT. LEVEL OF EVIDENCE: 4.

Incidence and Risk Factors for Major Surgical Complications in Patients With Complex Spinal Deformity: A Report From an SRS GOP Site.

STUDY DESIGN: Retrospective analysis of a prospectively collected single-center database. OBJECTIVES: To report the incidence of and identify risk factors for perioperative complications in surgically treated pediatric and adult patients with complex spine deformities in an underserved region and Scoliosis Research Society Global Outreach Program site. SUMMARY OF BACKGROUND DATA: Surgical treatment for complex spinal deformity is challenging and requires a multidisciplinary approach for optimal management. The incidence and risk factors for major perioperative complications in outreach sites with limited resources are unknown. METHODS: A total of 427 consecutive patients who underwent instrumented spinal fusion for complex spinal deformities were reviewed. Clinical, radiographic, and demographic data were reviewed at preoperative and postoperative time points, and potential risk factors for perioperative complications were assessed. The authors performed multivariate logistic regression analysis (LRA) to determine independent risk factors for postoperative complications and neurological deficits. RESULTS: Major complications were seen in 85 cases, which consisted of neurologic deficits (n = 27; 17 transient and 10 permanent), wound infections (n = 17), implant-related problems (n = 35), progressive deformity (n = 13), and death (n = 6). Among the possible risk factors, univariate LRA indicated 3-column osteotomies as a risk factor for postoperative major complications and multivariate LRA indicated 3-column osteotomies as an independent risk factor for neurological deficit. Curves 100° and above were at higher risk for complications. CONCLUSIONS: Postoperative complications were seen in 20% of surgically treated patients with complex spine deformities at a Scoliosis Research Society SRS Global Outreach Program site. Three-column osteotomies were identified as an independent risk factor of both postoperative complications and neurological deficits. The significant observed correlation of 3-column osteotomies and postoperative neurological deficits should serve as a guide for surgeons in the preoperative planning and management of severe spinal deformities, especially in locations with limited resources. Patients undergoing correction of large curves may also have a higher complication rate.

Early outcomes and complications of posterior vertebral column resection.

BACKGROUND CONTEXT: Hyperkyphosis confers a significant risk for neurologic deterioration as well as compromised cardiopulmonary function. Posterior vertebral column resection (PVCR) is a challenging but effective technique for spinal cord decompression and deformity correction that even under the setting of limited resources can be performed to reduce the technical difficulties, the operating time, and possibly the complications of the traditional two-staged vertebral column resection (VCR). PURPOSE: To report on the results of VCR performed through a single posterior approach (PVCR) in the treatment of severe rigid kyphosis in a series of patients treated and followed at a Scoliosis Research Society Global Outreach Program site in West Africa. STUDY DESIGN: Retrospective case series. PATIENT SAMPLE: Forty-five consecutive patients treated with PVCR for correction of severe rigid kyphosis. OUTCOME MEASURES: Clinical and radiographic outcomes and complications; Scoliosis Research Society outcome instrument (SRS-22). METHODS: From 2002 to 2009, 45 patients (20 male and 25 female) underwent PVCR for kyphosis from congenital deformity (nine) or secondary to tuberculosis of the spine (36). Preoperative demographics, preop and postop neurologic status, SRS-22 scores and complications were recorded; upright full spine X-rays were available in all patients. Mean age was 14 years (6-47 years); mean follow-up 27 months (2-79 months). Mean preoperative kyphosis measured 108°. The deformity apex was resected via a costotransverse (thoracic) or posterolateral (lumbar) approach; neurosurveillance with sensory (somatosensory-evoked potentials) and motor (motor-evoked potentials) potential was used in all cases. Posterior instrumentation was used in all patients, and anterior structural cage was used in 32 patients. RESULTS: Intraoperative monitoring changes occurred in 10 patients (22%), and one patient progressed to complete spinal cord injury. Average preoperative local kyphosis was 108° and corrected to 600 postoperatively. Postoperatively, no additional patient showed neurologic deterioration; of the 11 patients with preoperative gait disturbances, 4 improved to normal gait, 5 remained the same, and 2 showed deterioration of their walking ability to nonambulating level. Total SRS-22 scores improved from 3.18 to 3.54 (p=.01), primarily self-image domain. CONCLUSIONS: Posterior vertebral column resection was successfully undertaken for the management of thoracic and thoracolumbar hyperkyphosis, demonstrating improvements in overall kyphosis and clinical outcome. Neuromonitoring provided the required safety to perform these challenging complex spine deformity procedures.

Uncommon complication after revision hip surgery.

Cauda equina syndrome is an uncommon complication of ankylosing spondylitis characterized by the slow and insidious development of severe neurologic impairment related to dural ectasia. This report describes a unique case of cauda equina syndrome in a patient with ankylosing spondylitis after hip revision surgery. A 70-year-old man with long-standing ankylosing spondylitis underwent standard hip revision surgery; combined spinal and general anesthesia was administered. Pain was controlled with intravenous opioids postoperatively (patient-controlled analgesia). As per routine protocol, on the first postoperative day, the patient remained supine on a hip abduction pillow; mobilization was initiated on the second postoperative day. On postoperative day 1, the patient had severe low back pain that was controlled with patient-controlled analgesia. On postoperative day 2, the Foley catheter was removed and the patient sat and dangled. Back pain persisted while supine; in addition, the patient noticed involuntary loss of urine. On postoperative day 3, the patient had below-the-knee numbness that progressed to saddle anesthesia and foot flexor and extensor weakness. An epidural hematoma was suspected and urgent magnetic resonance imaging was performed, which showed severe degenerative stenosis at the L4-L5 level (mainly by dense ligamentum flavum). An L4-L5 decompression and instrumented fusion was performed; intraoperatively, L4-L5 was found to be the sole mobile segment. The extension of the spine in the supine position that completely obliterated the spinal canal was considered the mechanism of cauda equina syndrome. The intensity of back pain is a good indicator of a severe spinal lesion; however, pain can be dampened by intravenous opioids. High suspicion is required in patients with preexisting spinal pathology, such as ankylosing spondylitis.

Surgical Risk Stratification Based on Preoperative Risk Factors in Severe Pediatric Spinal Deformity Surgery.

STUDY DESIGN: Retrospective review. OBJECTIVE: The purpose of this study is to review the postoperative complications in pediatric patients undergoing spine surgery and to establish a preoperative classification that stratifies surgical risk and case difficulty. SUMMARY OF BACKGROUND DATA: Pediatric spinal deformity (PSD) surgery can be challenging technically as well as economically. Often, a multidisciplinary approach to managing these patients is necessary. In an environment where resources are limited, such as in global outreach efforts, a method for stratifying PSD surgical cases can be useful for allocating appropriate resources and assigning appropriate skill sets in order to optimize patient outcomes and to streamline efforts. MATERIALS AND METHODS: A total of 145 consecutive PSD patients who underwent instrumented spinal fusion were reviewed. Radiographic measurements and demographic data were reviewed. A classification was established based on the curve magnitude, etiology, ASA grade, number of levels fused, the preoperative neurologic status, body mass index and type of osteotomies. Multiple regression analysis (MRA) and logistic regression analysis (LRA) were applied to indicate risk factors for complications. RESULTS: The average age was 14.3 years (10-20 years). The etiology was idiopathic scoliosis (n = 71), congenital scoliosis (n = 38), infectious (n = 11), and others. 23 patients had neurologic deficits preoperatively. Twenty-three patients had a posterior vertebral column resection. Patients were classified as Level 1 (n = 5), Level 2 (n = 19), Level 3 (n = 24), Level 4 (n = 58), and Level 5 (n = 39). Intraoperative neuro-monitoring changes were observed in 46 cases. Major complications were seen in 45 cases. A major complication consisted of implant related (n = 13), deep wound infection (n = 8), neurologic deficit (n = 7), death (n = 2), and others (n = 9). MRA demonstrated a significant correlation between classified level and %EBL/TBV, operative time, and complication rate. The risk level predicted the occurrence of general (odds ratio [OR] = 1.54; 95% confidence interval [CI] = 1.08-2.21; p = .019) and neurologic (OR = 3.34; 95% CI = 1.06-17.70; p = .036) complications. Osteotomy and resection procedures were independent predictors for postoperative neurologic complications (OR = 1.7, 95% CI = 1.11-2.85; p = .015). CONCLUSION: Corrective spine surgery for complex pediatric deformity is challenging and carries a substantial risk. No single parameter appears to independently predict postoperative complications. However, when all risk factors are considered, there is a trend toward increased intraoperative electromonitoring change and postoperative neurologic risk with the higher level score in our classification. The newly established surgical risk stratification based on patient-specific clinical and radiographic factors can guide surgeons in their preoperative planning and surgical management of severe spine deformity in order to achieve optimal outcomes.

Common surgical complications in degenerative spinal surgery.

The rapid growth of spine degenerative surgery has led to unrelenting efforts to define and prevent possible complications, the incidence of which is probably higher than that reported and varies according to the region of the spine involved (cervical and thoracolumbar) and the severity of the surgery. Several issues are becoming progressively clearer, such as complication rates in primary versus revision spinal surgery, complications in the elderly, the contribution of minimally invasive surgery to the reduction of complication rate. In this paper the most common surgical complications in degenerative spinal surgery are outlined and discussed.

Late treatment of tuberculosis-associated kyphosis: literature review and experience from a SRS-GOP site.

INTRODUCTION: Spinal tuberculosis (TB) accounts for approximately half of all cases of musculoskeletal tuberculosis. Kyphosis is the rule in spinal tuberculosis and has potential detrimental effects on both the spinal cord and pulmonary function. Late-onset paraplegia is best avoided with the surgical correction of severe kyphosis, where at the same time anterior decompression of the cord is performed and the remnants of the tuberculosis-destroyed vertebral bodies are excised. MATERIAL AND METHODS: Review of the literature on late surgical treatment of TB-associated kyphosis; description and comparative analysis of the different surgical techniques. RESULTS: Kyphosis can be corrected either at the acute stage or at the healed late stage of tuberculous infection. In the late stage, the stiffness of the spine and chronic lung disease are additional considerations for the surgical approach and technique. Contrary to the traditional anterior transpleural approach used in the acute spinal tuberculosis infection, extrapleural approaches, either antero-lateral or direct posterior, are favored in late treatment. CONCLUSION: The correction of deformity is only feasible with three-column osteotomies, and posterior vertebral column resection (PVCR) is the treatment of choice in extreme kyphosis. The prognosis of the neurologic deficit (late paraplegia) is dependent on the extent of gliosis of the spinal cord.

Pathophysiology and biomechanics of the aging spine.

AGING OF THE SPINE IS CHARACTERIZED BY TWO PARALLEL BUT INDEPENDENT PROCESSES: the reduction of bone mineral density and the development of degenerative changes. The combination of degeneration and bone mass reduction contribute, to a different degree, to the development of a variety of lesions. This results in a number of painful and often debilitating disorders. The present review constitutes a synopsis of the pathophysiological processes that take place in the aging spine as well as of the consequences these changes have on the biomechanics of the spine. The authors hope to present a thorough yet brief overview of the process of aging of the human spine.

Posterior decompression and stabilization, and surgical vertebroplasty with the vertebral body stenting for metastatic vertebral and epidural cauda equina compression.

We present the technique of combined posterior decompression and spinal instrumentation, and surgical (open) vertebroplasty using a novel system called vertebral body stenting (VBS) during a single session in a patient with metastatic vertebral and epidural cauda equina compression.

Spontaneous posterior iliac crest regeneration enabling second bone graft harvest; a case report.

We present a case of a revision spinal fusion in which successful bone graft reharvesting was performed from the posterior iliac crest 4 years after initial intracortical harvesting. To date, only anterior iliac crest regeneration has been reported in orthopedic trauma patients. A 70-year-old man with a history of two prior instrumented lumbar fusion operations developed thoracolumbar kyphosis junctional to the lumbosacral fusion mass. His first operation was an instrumented posterolateral lumbar fusion L1 to L5, where bone graft was harvested from the right iliac crest using the intracortical harvesting technique. The second procedure was performed 18 months later and consisted of an extension of the fusion to the sacrum due to L5-S1 level derived symptoms. The bone graft for this procedure was taken with the same technique from the left iliac crest. The development of thoracolumbar junctional kyphosis necessitated the third operation, which consisted of a same-day anterior-posterior extension of the fusion to T10. Prior to this third procedure, a spinal computer tomography was performed that documented regeneration of the cancellous bone in the right iliac crest. This permitted reharvesting of almost 40 ml of cancellous bone using the intracortical bone harvesting technique from the right iliac crest. Histological analysis showed mature bone. Cancellous bone regeneration and restoration of the local anatomy of the ilium are possible after intracortical bone harvesting. This regeneration can provide autologous bone graft to assist fusion in subsequent operations.

Unipedicular balloon kyphoplasty for the treatment of osteoporotic vertebral compression fractures: early results.

INTRODUCTION: The traditional bipedicular kyphoplasty was proved to be safe and effective for the treatment of pain associated with osteoporotic vertebral compression fractures (VCFs). Nevertheless, unilateral kyphoplasty would be an attractive alternative to the traditional bipedicular kyphoplasty owing to theoretical speed, safety, and less expense; thus far, the biomechanical testing showed that experimental unilateral kyphoplasty had properties comparable with bipedicular kyphoplasty. To date, no clinical data are available regarding the efficacy and safety of unilateral balloon kyphoplasty. In this prospective observational study, the clinical and radiographic outcomes of the unipedicular (unilateral) balloon kyphoplasty in osteoporotic VCFs are evaluated. METHODS: Three hundred and seventeen kyphoplasty procedures were performed in 142 patients with osteoporotic VCFs using the unilateral technique. This technique involves the unilateral cannulation of the center of the vertebral body and the placement of a single balloon tamp. To evaluate improvement in pain and physical function, preoperative and postoperative scores of visual analog scale (VAS), SF-36, and Oswestry Disability Index (ODI) were compared at 3 and 12 months postoperatively. Complications related to the procedure and cement extravasation rates were recorded. Height restoration and overall coronal and sagittal spinal alignment were assessed preoperatively and postoperatively. RESULTS: Significant improvement on the VAS, SF-36 scores, and ODI was noted at 3 months postoperatively; these results were preserved at the 12-month follow-up for the 30 patients who completed the SF-36 questionnaire (VAS/ODI scores were available only for 19 of the 30 patients also showing sustained improvement). No complication was recorded; 34 cases (10.73%) of cement extravasation were all asymptomatic. Mean middle height restoration was found 48.9%; when vertebral levels treated were stratified into 2 groups, with or without height restoration (90.1% and 9.9% of all levels, respectively), corrected mean middle height restoration was found 54%. No lateral wedging or changes in the coronal alignment was observed in the unipedicular group. CONCLUSIONS: Unipedicular (unilateral) extrapedicular kyphoplasty is both a safe and efficacious alternative to the traditional bipedicular kyphoplasty for the treatment of painful osteoporotic VCFs. As a technique, it is faster, less expensive, and involves less radiation exposure for the surgical suite personnel.

Sacral fractures complicating thoracolumbar fusion to the sacrum.

STUDY DESIGN: Case series. OBJECTIVE: To report on the rare complication of sacral fractures after long instrumented thoracolumbar fusions to the sacrum. SUMMARY OF BACKGROUND DATA: Rigid spinal fusion with instrumentation results in redistribution of forces in the spine that can cause the adjacent segments to degenerate and fail. Rarely in long thoraco-lumbosacral fusion, these forces may lead to sacral fractures; only 4 cases are reported in the literature. METHODS: Five patients with sacral fractures are presented; one had the fusion performed at a different institution. Patients' characteristics, radiographic findings, and final operative treatment are discussed. RESULTS: Sagittal imbalance after the index operation (thoraco-lumbosacral fusion), osteoporosis, and obesity were potentially associated factors. Initial nonoperative treatment failed to improve patients' symptoms. Surgery was performed at an average of 3.25 months (range, 2-8 months) in 4 patients, and soon after presentation in the patient operated elsewhere (presented 18 months after the sacral fracture). The signs of failed L5-S1 fusion, present in 3 patients, were considered to be additional surgical indication. At surgery the posterior instrumentation was extended to the pelvis. Both the fracture and the failed anterior interbody fusion were addressed through an anterior approach in 4 cases and in one case with a posterior ascending titanium cage spanning from S2 to L5. Sagittal balance was restored only in the last patient, where at the time of the revision operation a pedicle subtraction osteotomy was performed. Pain resolved in all patients after surgery and to the latest follow-up (range, 6-36 months). CONCLUSION: Relapse of low back or buttock pain and leg pain after thoracolumbar fusion to the sacrum may be related to a sacral fracture, difficult to diagnose in conventional radiographs. Surgery should be considered in the presence of a concomitant L5-S1 pseudarthrosis and when symptoms do not improve with the nonoperative treatment.

Osteoporotic vertebral fractures and collapse with intravertebral vacuum sign (Kümmel's disease).

The intravertebral vacuum phenomenon was first described by Kümmel and is also known as delayed vertebral collapse or vertebral pseudarthrosis. Clinically, it occurs in approximately 10% of vertebral osteoporotic fractures, mainly in the thoracolumbar zone, is accentuated on extension views and associated with benign fractures. Most patients are neurologically intact, and continued pain is a common symptom that responds well to stabilization. Various theories exist in the literature about the pathogenesis; data support a combination of ischemia and psuedarthrosis. The ultimate treatment plan must be individualized and involve decompression of neurologic elements--when present--and sufficient stabilization, which varies according to surgeon preference and the patient's combordities.

Lumbar microdiscectomy under epidural anesthesia: a comparison study.

BACKGROUND CONTEXT: Lumbar microdiscectomy is most commonly performed under general anesthesia, which can be associated with several perioperative morbidities including nausea, vomiting, atelectasis, pulmonary aspiration, and prolonged post-anesthesia recovery. It is possible that fewer complications may occur if the procedure is performed under epidural anesthesia. PURPOSE: To investigate the safety and efficacy of epidural anesthesia in elective lumbar microdiscectomies. STUDY DESIGN: A prospective study evaluating the relative morbidities associated with epidural anesthesia and general anesthesia for lumbar microdiscectomy. PATIENT SAMPLE: Forty-three patients scheduled for primary lumbar microdiscectomy. Two cohorts were formed and were studied separately; one observational of all the 43 patients, and a second cohort of 17 patients who agreed to enter in the randomized trial. OUTCOME MEASURES: The clinical outcome was determined by the presence of postoperative pain, the absence of anesthesia-related complications, and the overall postoperative recovery. METHODS: This was a prospective study. With institutional review board approval, 43 consecutive patients were enrolled in the study. However, only 17 patients agreed to be randomized to receive either general or epidural anesthesia for the procedure; the remaining 26 patients selected the type of anesthesia of their preference. Recorded data for all patients included: age; total surgical time; occurrence of nausea, vomiting, atelectasis, or cardiopulmonary complication; ability to arise out of bed on the day of surgery; and the total number of inpatient hospital days. Postoperative pain and satisfaction were assessed only in the randomized cohort. RESULTS: There were a total of 43 patients, with a mean age of 38.1 years. The patients undergoing epidural anesthesia were marginally older than those undergoing general anesthesia. The epidural and general anesthetic groups were not different with respect to surgical time, pain assessed with a linear visual analogue scale, hospital stay, or the likelihood of arising out of bed on the day of surgery. There were no major cardiopulmonary complications in either group. Patients with epidural anesthesia had significantly less nausea and vomiting. CONCLUSIONS: Epidural anesthesia as an alternative to general anesthesia has shown less postoperative nausea and vomiting in lumbar microdiscectomy. Nevertheless, given the small number of patients, this study should be considered as preliminary, showing small differences in minor potential complications.

Outcome of revision discectomies following recurrent lumbar disc herniation.

STUDY DESIGN: Retrospective study. OBJECTIVES: To assess the difference in the outcome score between a primary surgery to treat lumbar disc herniation and a revision surgery for recurrent herniation at the same location with the use of a validated lumbar spine outcome instrument. SUMMARY OF BACKGROUND DATA: Paucity of studies comparing the results of revision discectomy for true recurrent disc herniation at the same location to that reported for primary discectomy. METHODS: A total of 27 patients who had undergone revision discectomies for recurrent lumbar disc herniations were surveyed to assess their clinical outcomes. Patients were compared with a control group of 30 matched patients who had undergone only a primary discectomy. The spine module of the MODEMS outcome instrument was used to evaluate the patients' satisfaction, their pain and functional ability following discectomy, as well as their quality of life. All patients were also asked whether they were improved or worsened with surgery. Those undergoing revision surgery were asked whether the improvement following the second surgery was more or less than the improvement following the first surgery. RESULTS: Improvement following the repeat discectomy was not statistically different from the improvement that occurred in patients who underwent just the primary operation. Differences in residual numbness/tingling in the leg and/or the foot as well as in frequency of back and/or buttock pain were identified. CONCLUSION: Based on patient derived outcome data using a validated instrument, revision discectomy is as efficacious as primary discectomy in selected patients.