✓ Intramedullary spinal tuberculosis infection remains an extremely rare disease entity. In the most recent reviews only 148 cases have been reported in the world literature, although numerous recent reports from developing countries and on human immunodeficiency virus (HIV)—positive patients have increased this number. The authors present an unusual case of intramedullary tuberculoma in an HIV—negative patient from the southern United States who demonstrated no other signs or symptoms of tuberculosis infection. The authors believe that this is the first case of its kind to be presented in recent literature. The presentation of miliary disease via an isolated intramedullary spinal mass in a patient with no evident risk factors for tuberculosis infection emphasizes the importance of including tuberculosis in the differential diagnosis of spinal cord masses.
Case report and review of the literature
John K. Ratliff and Edward S. Connolly
John K. Ratliff and Edward H. Oldfield
Object. Clinically evident multiple pituitary adenomas rarely occur. The authors assess the incidence and clinical relevance of multiple adenomas in Cushing's disease.
Methods. A prospective clinical database of 660 pituitary surgeries was analyzed to assess the incidence of multiple pituitary adenomas in Cushing's disease. Relevant radiographic scans, medical records, and histopathological reports were reviewed.
Thirteen patients with at least two separate histopathologically confirmed pituitary adenomas were identified. Prolactinomas (nine patients) were the most common incidental tumors. Other incidental tumors included secretors of growth hormone ([GH], one patient) and GH and prolactin (two patients), and a null-cell tumor (one patient). In two patients, early repeated surgery was performed because the initial operation failed to correct hypercortisolism, in one instance because the tumor excised at the initial surgery was a prolactinoma, not an adrenocorticotropic hormone—secreting tumor. One patient had three distinct tumors.
Conclusions. Multiple pituitary adenomas are rare, but may complicate management of patients with pituitary disease.
John K. Ratliff and Edward H. Oldfield
Object. Although the use of multiple agents is efficacious in animal models of peripheral nerve injury, translation to clinical applications remains wanting. Previous agents used in trials in humans either engendered severe side effects or were ineffective. Because the blood—central nervous system barrier exists in nerves as it does in the brain, limited drug delivery poses a problem for translation of basic science advances into clinical applications. Convection-enhanced delivery (CED) is a promising adjunct to current therapies for peripheral nerve injury. In the present study the authors assessed the capacity of convection to ferry macromolecules across sites of nerve injury in rat and primate models, examined the functional effects of convection on the intact nerve, and investigated the possibility of delivering a macromolecule to the spinal cord via retrograde convection from a peripherally introduced catheter.
Methods. The authors developed a rodent model of convective delivery to lesioned sciatic nerves (injury due to crush or laceration in 76 nerves) and compared the results to a smaller series of five primates with similar injuries. In the intact nerve, convective delivery of vehicle generated only a transient neurapraxic deficit. Early after injury (postinjury Days 1, 3, 7, and 10), infusion failed to cross the site of injury in crushed or lacerated nerves. Fourteen days after crush injury, CED of radioactively-labeled albumin resulted in perfusion through the site of injury to distal growing neurites. In primates, successful convection through the site of crush injury occurred by postinjury Day 28. In contrast, in laceration models there was complete occlusion of the extracellular space to convective distribution at the site of laceration and repair, and convective distribution in the extracellular space crossed the site of injury only after there was histological evidence of completion of nerve regeneration. Finally, in two primates, retrograde infusion into the spinal cord through a peripheral nerve was achieved.
Conclusions. Convection provides a safe and effective means to deliver macromolecules to regenerating neurites in crush-injured peripheral nerves. Convection block in lacerated and suture-repaired nerves indicates a significant intraneural obstruction of the extracellular space, a disruption that suggests an anatomical obstruction to extracellular and, possibly, intraaxonal flow, which may impair nerve regeneration. Through peripheral retrograde infusion, convection can be used for delivery to spinal cord gray matter. Convection-enhanced delivery provides a promising approach to distribute therapeutic agents to targeted sites for treatment of disorders of the nerve and spinal cord.
John K. Ratliff and Paul R. Cooper
Object. The technique of cervical laminoplasty was developed to decompress the spinal canal in patients with multilevel anterior compression caused by ossification of the posterior longitudinal ligament or cervical spondylosis. There is a paucity of data confirming its superiority to laminectomy with regard to neurological outcome, preserving spinal stability, preventing postlaminectomy kyphosis, and the development of the “postlaminectomy membrane.”
Methods. The authors conducted a metaanalysis of the English-language laminoplasty literature, assessing neurological outcome, change in range of motion (ROM), development of spinal deformity, and complications. Seventy-one series were reviewed, comprising more than 2000 patients.
All studies were retrospective, uncontrolled, nonrandomized case series. Forty-one series provided postoperative recovery rate data in which the Japanese Orthopaedic Association Scale was used for assessing myelopathy. The mean recovery rate was 55% (range 20–80%). The authors of 23 papers provided data on the percentage of patients improving (mean ∼80%). There was no difference in neurological outcome based on the different laminoplasty techniques or when laminoplasty was compared with laminectomy. There was postlaminoplasty worsening of cervical alignment in approximately 35% and with development of postoperative kyphosis in approximately 10% of patients who underwent long-term follow-up review. Cervical ROM decreased substantially after laminoplasty (mean decrease 50%, range 17–80%). The authors of studies with long-term follow up found that there was progressive loss of cervical ROM, and final ROM similar to that seen in patients who had undergone laminectomy and fusion. In their review of the laminectomy literature the authors could not confirm the occurrence of postlaminectomy membrane causing clinically significant deterioration of neurological function. Postoperative complications differed substantially among series. In only seven articles did the writers quantify the rates of postoperative axial neck pain, noting an incidence between 6 and 60%. In approximately 8% of patients, C-5 nerve root dysfunction developed based on the 12 articles in which this complication was reported.
Conclusions. The literature has yet to support the purported benefits of laminoplasty. Neurological outcome and change in spinal alignment are similar after laminectomy and laminoplasty. Patients treated with laminoplasty develop progressive limitation of cervical ROM similar to that seen after laminectomy and fusion.
Juan C. Jimenez, Sepehr Sani, Berton Braverman, Harel Deutsch and John K. Ratliff
A desire to prevent complications resulting from spinal surgery led to the development of intraoperative monitoring. Intraoperative electromyography (EMG) provides useful diagnostic information regarding nerve root function during spinal and peripheral nerve surgeries. The C-5 nerve root is considered particularly vulnerable to injury during cervical surgery. Despite advances in techniques, the incidence of postoperative C-5 palsy has not changed.
The authors reviewed prospectively collected data obtained in 161 patients who underwent 171 cervical procedures. In 116 procedures, operative monitoring was modified to include continuous C-5 EMG from the deltoid muscle. In cases in which spontaneous C-5 activity occurred, an appropriate change in operative manipulation was made. A historical control group consisted of a retrospective review of 55 procedures that were monitored using conventional techniques.
In the retrospective cohort, four (7.3%) of 55 patients presented after undergoing surgery for C-5 nerve root palsy. In each patient conventional monitoring revealed unremarkable findings. In the prospective cohort, intraoperative spontaneous EMG activity necessitated a change in either positioning or operative technique in three cases. Only one patient (0.9%) experienced postoperative C-5 palsy. Postoperative C-5 palsy occurred in no patient in whom there was no intraoperative evidence of root irritation (p < 0.03, chi-square test).
The incidence of postoperative C-5 palsies was reduced from 7.3% to 0.9% due to intraoperative continuous EMG monitoring. No patient suffered a postoperative C-5 palsy when intraoperative evidence of root irritation was absent.
Nimesh Patel, Bradley Bagan, Sumeet Vadera, Mitchell Gil Maltenfort, Harel Deutsch, Alexander R. Vaccaro, James Harrop, Ashwini Sharan and John K. Ratliff
Many patients undergoing elective thoracic or lumbar fusion procedures are obese, but the contribution of obesity to complications in spine surgery has not been defined. The authors retrospectively assessed the prevalence of obesity in a cohort of patients undergoing thoracic and lumbar fusion and correlate the presence of obesity with the incidence of operative complications.
A retrospective review of consecutive patients treated by a single surgeon (J.K.R.) over a 36-month period at either Rush University Medical Center or the Neurological and Orthopedic Institute of Chicago was performed. The authors identified 332 elective thoracic and lumbar spine surgery cases; the cohort was restricted to include only patients with symptomatic degenerative conditions in need of an anterior, posterior, or combined anterior–posterior fusion. Cases of trauma, tumor, and infection and any case in which the procedure was performed for emergency indications were excluded. A total of 97 cases were identified; of these 86 procedures performed in 84 patients had adequate follow-up material for inclusion in the present study. A broad definition of complications was used. Complications were divided into adverse events (minor) and significant complications (major) based on their impact on patient outcome. Stepwise multivariate logistic regression was used to identify which variables had a significant effect on the risk of complications. Variables considered were body mass index (BMI), height, weight, age, sex, presence or absence of diabetes mellitus (DM) and/or hypertension, number of levels fused (single compared with multiple), and type of surgery performed.
The mean BMI for the cohort was 28.8 (95% confidence interval 24.4–30.3); 60 patients (71.4%) were considered overweight or obese (BMI ≥ 25). There were 42 complications in 31 patients (36.9%); this included 19 significant complications in 17 patients (20.2%). Logistic regression revealed that the probability of a significant complication was related to BMI (p < 0.04); the chance of a significant complication was 14% with a BMI of 25, 20% with a BMI of 30, and 36% with a BMI of 40. Positioning-related palsies were only found in extremely obese patients (BMI ≥ 40). The probability of minor complication occurrence increased with age (p < 0.02), not BMI. The rate of complications was independent of sex as well as the presence of DM or hypertension. A standard collection of complications occurred, including wound infection (three cases), cerebrospinal fluid leakage (eight cases, one requiring reoperation), deep vein thrombosis (two cases), cardiac events (four cases), symptomatic pseudarthrosis (one case), pneumonia (three cases), prolonged intubation (two cases), urological issues (eight cases), positioning-related palsy (two cases), and neuropathic pain (two cases).
Obesity is a prevalent condition in patients undergoing elective fusion for degenerative spinal conditions and may increase the prevalence and incidence of perioperative complications. In their analysis, the authors correlated increasing BMI and increased risk of significant postoperative complications. The correlation of obesity and perioperative complications may assist in the preoperative evaluation and selection of patients for surgery.
Sanjay Yadla, Bryan LeBude, Gabriel C. Tender, Ashwini D. Sharan, James S. Harrop, Alan S. Hilibrand, Alexander R. Vaccaro and John K. Ratliff
Traumatic Grade V thoracolumbar spondylolisthesis, or traumatic spondyloptosis (severe translation injuries), are uncommon spinal injuries. To the best of the authors' knowledge, this article represents the first reported case series of these unique spinal lesions.
The authors undertook a retrospective review of a tertiary care regional spinal cord injury patient population treated over a 10-year period (1997–2007). They analyzed data regarding age, sex, mechanism of injury, neurological status, and treatment.
Five patients were identified (3 men and 2 women) with ages ranging from 17 to 44 years. All patients had sustained high-energy closed spinal injuries: 3 motor vehicle accidents, 1 injured in a building collapse, and 1 hurt by a fallen steel beam. Four patients, all with sagittal-plane spondyloptosis, had a complete neurological deficit (American Spinal Injury Association [ASIA] Grade A), and 1, with coronal-plane spondyloptosis, presented with an incomplete neurological deficit (ASIA Grade C). Four patients had sustained concurrent multisystem trauma. All patients underwent surgery: an isolated posterior fusion in 2 and combined posterior-anterior fusion in 3. Only the patient with an incomplete neurological deficit (coronal-plane spondyloptosis) recovered neurological function postoperatively.
Traumatic thoracolumbar junction spondyloptosis is rare. Surgical reconstruction and stabilization allow for early mobilization and rehabilitation. In the present series, a patient with coronal-plane spondyloptosis presented with preserved neurological function. This may be due to the result of differences in resultant neurological compression due to displacement mechanics compared with sagittally displaced injuries.
John K. Ratliff, Bryan Lebude, Todd Albert, Tony Anene-Maidoh, Greg Anderson, Phillip Dagostino, Mitchel Maltenfort, Alan Hilibrand, Ashwini Sharan and Alexander R. Vaccaro
Definitions of complications in spinal surgery are not clear. Therefore, the authors assessed a group of practicing spine surgeons and, through the surgeons' responses to an online and emailed survey, developed a simple definition of operative complications due to spinal surgery. To validate this assessment, the authors revised their survey to make it appropriate for a lay audience and repeated the assessment with a cohort of patients who underwent spine surgery.
The authors surveyed a cohort of practicing spine surgeons via email and a web-based survey. Surgeons were presented with various complication scenarios and were asked to grade the presence or absence of a complication as well as complication severity, with responses limited to “major complication” and “minor complication/adverse event.” The authors administered a similar assessment, modified for lay persons, to patients in a spinal surgery clinic.
Complete responses were obtained from 229 surgeons; orthopedic surgeons comprised the majority of respondents (73%). The authors obtained completed surveys from 197 patients. Overall, there was consistent agreement between physicians and patients regarding the presence or absence of a complication in the majority of scenarios (8 [73%] of 11 scenarios with agreement that a complication was present). The overall kappa value, evaluating major versus minor complication, and presence or absence of a complication over the entire cohort, was fair (κ = 0.21). The authors found greater variation between the cohorts when evaluating complication severity. Patients were consistently more critical than physicians in the majority of scenarios in which a difference was evident. In 4 scenarios, patients were more likely than surgeons to deem the scenario a complication and to grade the complication as major versus minor (p < 0.01). In 3 additional scenarios, patients were more likely than physicians to grade a major complication as opposed to minor complication (p < 0.01). In only 1 scenario were patients less likely than physicians to report a complication (p < 0.001).
Comparing responses of spine surgeons and patients who underwent spinal surgery in assessing a group of common postoperative events, the authors found significant agreement on perception of presence of a complication in the majority of scenarios reviewed. However, patients were consistently more critical than surgeons when differences in reporting were found. The authors' data underscore the importance of reconciling differing opinions regarding complications through open discussions between physicians and patients to ensure accurate patient expectations of planned medical or surgical interventions.