bluuebunny/crossref_metadata_2025 huggingface dataset:
Significance of a persistent positive straight leg raising test after lumbar disc surgery
Authors: Jönsson Bo , Strömqvist Björn
Published: May 2009

Object. Results of the straight leg raising (SLR) test provide the clinician with valuable information regarding possible causes of a patient's pain. In a previous study the results have also demonstrated a correlation between the outcome of the test and the severity of pain, as well as the prognostic value of the test; patients for whom the SLR test is persistently positive postoperatively appear to have a poorer short-term outcome. In a prospective study of 200 consecutive patients who underwent surgery for disc herniation, the authors evaluated the frequency of repeated surgery and outcome of surgery in patients with a persistent postoperative positive SLR test.

Methods. The preoperative radiological evaluation included myelography, computerized tomography scanning, and/or magnetic resonance imaging. Preoperatively as well as 4, 12, and 24 months postoperatively, each patient was interviewed and examined using a standard protocol in which common symptoms and signs were described. The result of the SLR test was also classified into one of four categories: positive 0 to 30°; positive 30 to 60°, positive greater than 60°, or negative, and the surgical results were evaluated using a four-grade scale.

Preoperatively, the SLR test was positive in 86% of patients. At 4 months postoperatively, 22% still had a positive SLR test. For the patients whose SLR test was positive 4 months postoperatively, the long-term outcome at all three follow-up examinations was inferior; this difference was statistically significant.

Conclusions. During the 2-year period, the reoperation rate was 18% (eight of 44) in patients with a positive postoperative SLR test compared with 4.5% (seven of 156) in patients whose postoperative SLR test was negative. A postoperative positive SLR test thus correlates to an unfavorable surgical outcome.
Visceral and vascular complications resulting from anterior lumbar interbody fusion
Authors: Rajaraman Viswanathan , Vingan Roy , Roth Patrick , Heary Robert F. , Conklin Lisa , Jacobs George B.
Published: May 2009

Object. The literature on abdominal and general surgery—related complications following anterior lumbar interbody fusion (ALIF) is scant. In this retrospective review of 60 patients in whom ALIF was performed at their institutions between 1996 and 1998, the authors detail the associated complications and their correlation with perioperative factors. The causes, strategies for their avoidance, and the clinical course of these complications are also discussed.

Methods. The study group was composed of 31 men and 29 women whose mean age was 42 years (range 29–71 years). The preoperative diagnosis was discogenic back pain in 33 patients (55%); failed back syndrome in 11 (18.3%); pseudarthrosis in five (8.3%); postlaminectomy syndrome in four (6.6%); spondylolisthesis in three (5%); burst fracture in two (3.3%); and malignancy in two (3.3%). A retroperitoneal approach to the spine was used in 57 of the 60 patients. One interspace was exposed in 28 patients (46.6%), two in 28 (46.6%), and three in four (6.6%). Discectomy and interbody fusion in which the authors placed titanium cages or bone dowels was performed in 56 patients and corpectomy with instrumentation in four. Seven (11.6%) of 60 patients had undergone previous abdominal surgery and 29 (48.3%) had undergone previous spinal surgery. The follow-up period averaged 12 ± 4 months (mean ± standard deviation). Twenty-four general surgery—related complications occurred in 23 patients (38.3%), including sympathetic dysfunction in six; vascular injury in four; somatic neural injury in three; sexual dysfunction in three; prolonged ileus in three; wound incompetence in two; and deep venous thrombosis, acute pancreatitis, and bowel injury in one patient each. There were no deaths. The incidence of complications was not associated with underlying diagnosis (p > 0.1), age (p > 0.5), previous abdominal or spinal surgery (p > 0.1), or the number of levels exposed (p > 0.1).

Conclusions. This report provides a detailed analysis of the general surgery—related complications following ALIF. Although many of these complications have been recognized in the literature, the significance of sympathetic dysfunction appears to have been underestimated. The high incidence of complications in this series likely reflects the strict criteria. Many of these complications were minor and resolved over time without long-term sequelae.
Nontraumatic acute spinal subdural hematoma
Authors: Domenicucci Maurizio , Ramieri Alessandro , Ciappetta Pasquale , Delfini Roberto
Published: May 2009

✓ Acute subdural spinal hematoma occurs rarely; however, when it does occur, it may have disastrous consequences. The authors assessed the outcome of surgery for this lesion in relation to causative factors and diagnostic imaging (computerized tomography [CT], CT myelography), as well as eventual preservation of the subarachnoid space.

The authors reviewed 106 cases of nontraumatic acute subdural spinal hematoma (101 published cases and five of their own) in terms of cause, diagnosis, treatment, and long-term outcome.

Fifty-one patients (49%) were men and 55 (51%) were women. In 70% of patients the spinal segment involved was in the lumbar or thoracolumbar spine. In 57 cases (54%) there was a defect in the hemostatic mechanism. Spinal puncture was performed in 50 patients (47%). Late surgical treatment was performed in 59 cases (56%): outcome was good in 25 cases (42%) (in 20 of these patients preoperative neurological evaluation had shown mild deficits or paraparesis, and three patients had presented with subarachnoid hemorrhage [SAH]). The outcome was poor in 34 cases (58%; 23 patients with paraplegia and 11 with SAH).

The formation of nontraumatic acute spinal subdural hematomas may result from coagulation abnormalities and iatrogenic causes such as spinal puncture. Their effect on the spinal cord and/or nerve roots may be limited to a mere compressive mechanism when the subarachnoid space is preserved and the hematoma is confined between the dura and the arachnoid. It seems likely that the theory regarding the opening of the dural compartment, verified at the cerebral level, is applicable to the spinal level too. Early surgical treatment is always indicated when the patient's neurological status progressively deteriorates. The best results can be obtained in patients who do not experience SAH.

In a few selected patients in whom neurological impairment is minimal, conservative treatment is possible.
Occipitocervicothoracic fixation for spinal instability in patients with neoplastic processes
Authors: Jackson Robert J. , Gokaslan Ziya L.
Published: May 2009

Object. Occipitocervicothoracic (OCT) fixation and fusion is an infrequently performed procedure to treat patients with severe spinal instability. Only three cases have been reported in the literature. The authors have retrospectively reviewed their experience with performing OCT fixation in patients with neoplastic processes, paying particular attention to method, pain relief, and neurological status.

Methods. From July 1994 through July 1998, 13 of 552 patients who underwent a total of 722 spinal operations at the M. D. Anderson Cancer Center have required OCT fixation for spinal instability caused by neoplastic processes (12 of 13 patients) or rheumatoid arthritis (one of 13 patients). Fixation was achieved by attaching two intraoperatively contoured titanium rods to the occiput via burr holes and Luque wires or cables; to the cervical spinous processes with Wisconsin wires; and to the thoracic spine with a combination of transverse process and pedicle hooks. Crosslinks were used to attain additional stability. In all patients but one arthrodesis was performed using allograft.

At a follow-up duration of 1 to 45 months (mean 14 months), six of the 12 patients with neoplasms remained alive, whereas the other six patients had died of malignant primary disease. There were no deaths related to the surgical procedure. Postoperatively, one patient experienced respiratory insufficiency, and two patients required revision of rotational or free myocutaneous flaps. All patients who presented with spine-based pain experienced a reduction in pain, as measured by a visual analog scale for pain. All patients who were neurologically intact preoperatively remained so; seven of seven patients with neurological impairment improved; and six of seven patients improved one Frankel grade. There were no occurrences of instrumentation failure or hardware-related complications. In one patient a revision of the instrumentation was required 13.5 months following the initial surgery for progression of malignant fibrous histiosarcoma.

Conclusions. In selected patients, OCT fixation is an effective means of attaining stabilization that can provide pain relief and neurological preservation or improvement.
Endoscopic thoracic sympathectomy
Authors: Johnson J. Patrick , Obasi Chinyere , Hahn Michael S. , Glatleider Paul
Published: May 2009

Object. Thoracic sympathectomy has evolved as a treatment option for patients with hyperhidrosis and pain disorders. In the past, surgical procedures were highly invasive and caused significant morbidity, but the minimally invasive thoracoscopic procedure provides detailed visualization of the sympathetic ganglia and is associated with minimal postoperative morbidity.

Methods. The authors performed 112 thoracoscopic sympathectomy procedures in 65 patients, and the outcomes were equivalent to those previously established for open surgical techniques; however, the rate of surgery-related morbidity, length of hospital stay, and time until return to normal activity were substantially reduced. Complications and recurrence of symptoms were comparable with those demonstrated in previous reports. Overall patient satisfaction and willingness to undergo a repeated operative procedure ranged from 66 to 99%. Postoperatively, higher satisfaction rates were observed in patients with hyperhidrosis whereas in those with pain syndromes, satisfaction rates were lower.

Conclusions. Minimally invasive thoracoscopic sympathectomy procedures are useful in treating sympathetically mediated disorders, and the results indicate that the procedure is associated with reduced morbidity and similar outcome when compared with results obtained after open surgery. Hyperhidrosis is well treated, but patients with pain syndromes have significantly poorer outcomes.
Apoptosis following spinal cord injury in rats and preventative effect of N-methyl-d-aspartate receptor antagonist
Authors: Wada Shoichi , Yone Kazunori , Ishidou Yasuhiro , Nagamine Tomonori , Nakahara Shinji , Niiyama Takahito , Sakou Takashi
Published: May 2009

Object. The aims of this study were to clarify the histological and histochemical changes associated with cell death in the spinal cord after acute traumatic injury and to examine the role of excitatory amino acid release mediated by N-methyl-d- aspartate (NMDA) receptors.

Methods. Following laminectomy, the spinal cord in 70 rats was injured at the T-9 level by applying extradural static weight—compression, in which a cylindrical compressor was used to induce complete and irreversible transverse spinal cord injury (SCI) with paralysis of the lower extremities. The injured rats were killed between 30 minutes and 14 days after injury, and the injured cord was removed en bloc. Rats that received NMDA receptor antagonist (MK-801) were killed at the same time points as those that received saline. The specimens were stained with hematoxylin and eosin, Nissl, and Klüver—Barrera Luxol fast blue and subjected to in situ nick-end labeling, a specific in situ method used to allow visualization of apoptosis. Thirty minutes post-SCI, a large hematoma was observed at the compressed segment. Six hours after injury, large numbers of dead cells that were not stained by in situ nick-end labeling were observed. Between 12 hours and 14 days postinjury, nuclei stained by using the in situ nick-end labeling technique were observed not only at the injury site but also in adjoining segments that had not undergone mechanical compression, suggesting that the delayed cell death was due to apoptosis. The number of cells stained by in situ nick-end labeling was maximum at 3 days postinjury. The results of electron microscopic examination were also consistent with apoptosis. In the MK-801—treated rats, the number of cells stained by in situ nick-end labeling was smaller than in nontreated rats at both 24 hours and 7 days after injury.

Conclusions. These findings suggest that NMDA-receptor activation promotes delayed neuronal and glial cell death due to apoptosis.
Plexiform neurofibroma of the cauda equina
Authors: Nadkarni Trimurti D. , Rekate Harold L. , Coons Stephen W.
Published: May 2009

✓ Plexiform neurofibroma of the cauda equina has been reported only twice previously. The authors report the first pediatric patient in whom such a tumor has been found. A 4-year-old boy presented with low-back pain that radiated bilaterally into the L-4 and L-5 dermatomes. A dermal sinus noted at the midthoracic level was surrounded by a hemangiomatous lesion. Magnetic resonance imaging confirmed the presence of the dermal sinus and revealed a well-defined lumbosacral mass that showed heterogeneous intensity with irregular enhancement. Intraoperatively, a solid mass, which engulfed the entire cauda equina, could not be dissected from the roots. The dermal sinus tract, however, was excised from the thoracic spine. The patient underwent radiotherapy to control the tumor and relieve his pain. Plexiform neurofibromas of the cauda equina are characterized by an insidious and progressive clinical course. The tumor mass may engulf all the roots of the cauda equina. No plexiform neurofibroma of the cauda equina has been reported to be associated with neurofibromatosis Type 1. The authors assume that the thoracic-level dermal sinus observed in this child was an incidental finding.
Anomaly of the axis causing cervical myelopathy
Authors: Asakawa Hiroyuki , Yanaka Kiyoyuki , Narushima Kiyoshi , Meguro Kotoo , Nose Tadao
Published: May 2009

✓ Although the craniovertebral junction is one of the most common sites at which anomalies develop, spina bifida occulta of the axis (C-2) associated with cervical myelopathy is extremely rare. The authors present the case of a 46-year-old man who developed progressive tetraparesis caused by a cervical canal stenosis at the level of the axis. The spinal cord was compressed by an invaginated bifid lamina of the axis. The patient made a remarkable recovery after undergoing decompressive laminectomy of C-3 and removal of the bifid posterior arch of the axis.
Anterior sacral meningocele associated with a rectal fistula
Authors: Fitzpatrick Michael Owen , Taylor William A. S.
Published: May 2009

✓ The authors report a case of anterior sacral meningocele associated with a rectal fistula in a patient who had presented 20 years earlier with bacterial meningitis. To their knowledge, this is the first case in which a rectal fistula developed due to an anterior sacral meningocele. The clinical presentation, diagnosis, and treatment of this uncommon lesion is discussed.
Magnetic resonance imaging—monitored conservative management of traumatic spinal epidural hematomas
Authors: Rosa Giovanni La , d'Avella Domenico , Conti Alfredo , Cardali Salvatore , Torre Domenico La , Cacciola Fabio , Longo Marcello , Tomasello Francesco
Published: May 2009

✓ Spinal epidural hematomas (SEHs) are uncommon complications of traumatic injury to the spine. Emergency surgical evacuation is the standard treatment. Although it is recognized in the literature, the possibility of nonsurgical treatment of traumatic SEH is far from being codified. The authors report excellent outcomes in four conservatively managed patients who had sustained a severe spine injury with fracture of the lumbar vertebral body and in whom traumatic SEHs were diagnosed by magnetic resonance imaging. Although in the authors' experience a good spontaneous outcome in this subgroup of minimally symptomatic patients harboring moderate-sized SEHs has been achieved, further studies are necessary to understand the real spectrum of nonsurgical treatment of such lesions.
Complex atlantoaxial fractures
Authors: Guiot Bernard , Fessler Richard G.
Published: May 2009

Object. The authors conducted a retrospective study to evaluate the treatment of complex C1–2 fractures.

Methods. There were 10 cases of complex C1–2 fractures. Six patients were men (median age 58 years) and four patients were women (median age 55.5 years). Injuries resulted from seven falls, two motor vehicle accidents, and one diving incident. Three patients suffered from upper-extremity weakness. Neurological function in seven patients was intact preoperatively. Fracture combinations included six Jefferson/Type II odontoid, two anterior ring/Type II odontoid, one posterior ring/Type II odontoid, and one posterior ring/Type III odontoid/Type III hangman's fracture. All patients underwent surgery, five after halo immobilization for an average of 4 months failed to provide stability. Treatment included placement of six odontoid screws, one posterior C1–2 transarticular screw, one odontoid screw with anterior C1–2 transarticular screw fixation, one C1–2 transarticular screw with C1–2 Songer cable fusion, and one odontoid screw with bilateral C-2 pedicle screw fixation. Specific treatment was determined by the combination of fractures. Postoperatively, all patients were immobilized in a hard collar for 3 months. There were no intraoperative surgery-related complications. The mean follow-up period was 28.5 months. Neurological recovery was observed in one of three patients who presented with neurological deficits. Fusion occurred in all cases.

Conclusions. The goals in treating these complex fractures are to achieve early maximum stability and minimum reduction in range of motion. These are often competing phenomena. Frequently in cases of atlas—axis fracture, odontoid screw fixation combined with hard collar immobilization is the best therapy, provided the transverse atlantal ligament is competent. If not, C1–2 stabilization with placement of transarticular screws is required for best results.
Rigid occipitocervical fusion
Authors: Vale Fernando L. , Oliver Mark , Cahill David W.
Published: May 2009

Object. Despite 50 years of neurosurgical experience, occipitocervical fusion continues to present a technical challenge to the surgeon. Traditional nonrigid techniques applied in the occiput and cervical spine often fail secondary to postsurgical cranial settling or rotational deformity. Unlike widely used nonrigid and semirigid techniques, rigid fixation of the craniocervical junction should allow correction of deformity in any plane, provide immediate stability without need for external orthosis, and prevent cranial settling.

Methods. Since 1992, the senior author (D.W.C.) has used a rigid plate and screw fixation system for occipitocervical fusions. The technique proved to be more difficult than expected, and the procedure has evolved as experience was gained. The authors present a series of 24 patients and a technique that now involves the use of a custom-designed T-plate that is attached to the midline occipital “keel” at one end and to the spine at the other end by means of screw-fixed plates.

Conclusions. Although it is still evolving, the current technique for obtaining rigid occipitocervical fixation allows for immediate rigidity and stability of the spine without the use of an external orthosis (that is, in the absence of osteoporosis), may be extended to any level of the spine, may be used in the absence of posterior elements, prevents postsurgical cranial settling and restenosis, facilitates reduction of the spinal deformity in any plane, and sometimes eliminates the need for an anterior (transoral) decompressive procedure.
Endoscopic transpedicular thoracic discectomy
Authors: Jho Hae-Dong
Published: May 2009

Object. To minimize the invasiveness and maximize the adequacy of the decompressive procedure in thoracic discectomy, a 70° endoscope was adapted to perform transpedicular thoracic discectomy.

Methods. A posterior transpedicular approach was performed via a 2-cm transverse skin incision, aided by an operating microscope or a 0° lens endoscope. Using a 70° lens endoscope, discectomy was performed after obtaining direct visualization of the ventral aspect of the spinal cord dura mater. This surgical technique has been used in 25 patients. There were 12 men and 13 women whose ages ranged from 29 to 74 years (median 46 years). Thirteen patients experienced myelopathy, with or without radiculopathy, 10 presented with radiculopathy, and two patients suffered from segmental pain. The follow-up period ranged from 4 to 60 months (median 27 months). In 12 of 13 patients with myelopathy, excellent improvement was shown postoperatively. In the remaining patient, symptoms recurred after she was injured in a motor vehicle accident 3 months postsurgery. In nine of 10 patients with radiculopathy, pain resolved completely. In the one patient with right-sided hypochondral pain and in the two patients with segmental pain, no relief was obtained despite excellent discectomy results demonstrated on postoperative magnetic resonance images. The average length of hospital stay was overnight.

Conclusions. The use of a 70° lens endoscope through a transpedicular route has made thoracic discectomy comparable with cervical or lumbar discectomy in terms of minimal surgical invasiveness, recovery time, and complexity of the procedure.
Reoperation for herniated thoracic discs
Authors: Dickman Curtis A. , Rosenthal Daniel , Regan John J.
Published: May 2009

Object. In this review the authors address the surgical strategies required to resect residual herniated thoracic discs.

Methods. Data obtained in 15 patients who had undergone prior thoracic discectomy and who harbored residual or incompletely excised symptomatic thoracic discs were reviewed retrospectively. The surgical procedures that had failed to excise the herniated discs completely included 11 posterolateral approaches, one thoracotomy, and three thoracoscopyguided surgical procedures. Of the lesions that were incompletely resected or residual, there were 13 central calcified, two soft, 12 extradural, and three intradural discs. Indications for reoperation were often multiple in each patient and included misidentification of the level of disc disease at the initial operation (five cases), abandoning the procedure because of intraoperative spinal cord injury (three cases), inadequate visualization of the pathological entity (eight cases), migration of a soft disc fragment within the spinal canal (one case), and intradural disc extension (three cases). The symptoms at the time of reoperation included myelopathy in 13 patients and radicular pain in two patients. The mean interval before reoperation was 150 days (range 1 day–4 years). The reoperation procedures included one thoracotomy and 14 video-assisted thoracoscopic procedures performed ipsilateral (11 cases) or contralateral (four cases) to the site of the initial surgery.

The herniated disc material was excised completely in all 15 cases without causing new neurological deficits. Reoperation complications included atelectasis in three patients, intercostal neuralgia in two, a loosened screw that required removal in one, residual intradural disc herniation that required a second reoperation in one patient, and a cerebrospinal fluid leak in one patient. Of the 13 patients who experienced myelopathy prior to operation, 10 recovered neurological function and three stabilized. All patients with radicular pain improved.

Conclusions. Calcified, large, broad-based, centrally located, or transdural thoracic disc herniations can be difficult to resect. These lesions require a ventral operative approach to visualize the dura adequately for a safe and complete resection.
Surgical treatment of lumbar spinal stenosis in patients older than 75 years of age
Authors: Vitaz Todd W. , Raque George H. , Shields Christopher B. , Glassman Steven D.
Published: May 2009

Object. The purpose of this study was to evaluate the safety and efficacy of the surgical treatment of lumbar spinal stenosis in patients older than 75 years of age.

Methods. The authors reviewed the records of 65 patients with lumbar spinal stenosis who were at least 75 years of age at the time of surgery, which was performed between November 1990 and May 1996.

The 65 patients (43 women, 22 men; average age 78 years) underwent a total of 71 operations (one patient underwent three, and four patients underwent two). Fifteen patients (21%) underwent isolated lumbar decompression, and 56 patients (79%) underwent decompression in conjunction with posterior spinal fusion. There was an average of 1.7 levels decompressed per isolated lumbar decompression and 2.6 levels per decompression and fusion procedure. Seven patients (10%) experienced one or more serious postoperative complication, which included wound infection, septicemia, small bowel obstruction, stroke, myocardial infarction, gastrointestinal bleeding, and pulmonary embolus. In addition there was one intraoperative complication (hypotension [1%]) that required modification of the planned surgical procedure. No deaths were documented in the perioperative period.

Conclusions. With appropriate preoperative selection and evaluation, careful intraoperative monitoring, and attentive perioperative care, the surgical treatment of elderly patients with lumbar spinal stenosis can effect significant improvement with acceptable levels of morbidity and mortality.
Posterior lumbar interbody fusion with cages: an independent review of 71 cases
Authors: Agazzi Siviero , Reverdin Alain , May Daniel
Published: May 2009

Object. The authors conducted a retrospective study to provide an independent evaluation of posterior lumbar interbody fusion (PLIF) in which impacted carbon cages were used. Interbody cages have been developed to replace tricortical interbody grafts in anterior and PLIF procedures. Superior fusion rates and clinical outcomes have been claimed by the developers.

Methods. In a retrospective study, the authors evaluated 71 consecutive patients in whom surgery was performed between 1995 and 1997. The median follow-up period was 28 months. Clinical outcome was assessed using the Prolo scale. Fusion results were interpreted by an independent radiologist.

The fusion rate was 90%. Overall, 67% of the patients were satisfied with their outcome and would undergo the same operation again. Based on the results of the Prolo scale, however, in only 39% of the patients were excellent or good results achieved. Forty-six percent of the work-eligible patients resumed their working activity. Clinical outcome and return-to-work status were significantly associated with socioeconomic factors such as preoperative employment (p = 0.03), compensation issues (p = 0.001), and length of preoperative sick leave (p = 0.01). Radiographically demonstrated fusion was not statistically related to clinical outcome (p = 0.2).

Conclusions. This is one of the largest independent series in which PLIF with cages has been evaluated. The results show that the procedure is safe and effective with a 90% fusion rate and a 66% overall satisfaction rate, which compare favorably with those of traditional fixation techniques but fail to match the higher results claimed by the innovators of the cage techniques. The authors' experience confirms the reports of others that many patients continue to experience incapacitating back pain despite successful fusion and neurological recovery.
Intraspinal synovial cysts: 10-year experience at the Ochsner Clinic
Authors: Howington Jay U. , Connolly Edward S. , Voorhies Rand M.
Published: May 2009

Object. Although synovial cysts commonly involve the joints of the extremities, they are also found in the spinal canal. When symptomatic, they produce signs and symptoms consistent with nerve root and spinal cord compression. In this report the authors review the clinical presentations, radiological studies, and operative findings in 28 patients with intraspinal synovial cysts treated surgically at the Ochsner Clinic between 1988 and 1998.

Methods. The medical records and radiological studies obtained in 28 patients (31 intraspinal synovial cysts) were analyzed. Twenty-nine (94%) of the cysts were located in the lumbar, one in the thoracic (T8–9), and one in the cervicothoracic (C7—T1) spine. Sixteen (57%) of the 28 patients presented with radicular pain. The remaining patients presented either with neurogenic claudication (25%) or with radicular pain and an associated neurological deficit (18%). Each cyst was located adjacent to a facet joint in which there was evidence of degenerative disease.

Conclusions. Intraspinal synovial cysts are uncommon lesions most often found in the lumbar spine at the L4–5 level. They are invariably associated with facet degeneration and respond very well to surgical therapy.
Magnetic motor evoked potential monitoring in the rat
Authors: Linden R. Dean , Zhang Yi-Ping , Burke Darlene A. , Hunt Matthew A. , Harpring John E. , Shields Christopher B.
Published: May 2009

Object. The authors conducted a study to provide an objective electrophysiological assessment of descending motor pathways in rats, which may become a means for predicting outcome in spinal cord injury research.

Methods. Transcranial magnetic motor evoked potentials (TMMEPs) were recorded under various conditions in awake, nonanesthetized, restrained rats. Normative data were collected to determine the reproducibility of the model and to evaluate the effect of changing the stimulus intensity on the evoked signals. In addition, an experiment was performed to determine if the TMMEPs produced were the result of auditory startle response (ASR) potentials elicited by the sound generated by the movement of the copper coil inside its casing during magnetic stimulation.

Transcranial magnetic motor evoked potentials were elicited after magnetic stimulation. At 100% stimulus intensity, the mean forelimb onset latency was 4.2 ± 0.39 msec, and the amplitude was 9.16 ± 3.44 mV. The hindlimb onset latency was 6.5 ± 0.47 msec, and the amplitude was 11.47 ± 5.25 mV. As the stimulus intensity was decreased, the TMMEP onset latency increased and the response amplitude decreased. The ASR potentials were shown to have longer latencies, smaller amplitudes, and were more variable than those of the TMMEPs.

Conclusions. These experiments demonstrate that TMMEPs can be recorded in awake, nonanesthetized rats. The evoked signals were easy to elicit and reproduce. This paper introduces noninvasive TMMEPs as a new technique for monitoring the physiological integrity of the rat spinal cord.
Extensive arachnoid ossification with associated syringomyelia presenting as thoracic myelopathy
Authors: Slavin Konstantin V. , Nixon Randall R. , Nesbit Gary M. , Burchiel Kim J.
Published: May 2009

✓ The authors present the case of progressive thoracic myelopathy caused by the extensive ossification of the arachnoid membrane and associated intramedullary syrinx. Based on their findings and results of the literature search, they describe a pathological basis for this rare condition, discuss its incidence and symptomatology, and suggest a simple classification for various types of the arachnoid ossification. They also discuss the magnetic resonance imaging features of arachnoid ossification and associated spinal cord changes. The particular value of plain computerized tomography, which is highly sensitive in revealing intraspinal calcifications and ossifications, in the diagnostic evaluation of patients with a clinical picture of progressive myelopathy is emphasized.
Fracture of an ossified transverse ligament
Authors: Crossman John E. , Stevens John M. , Crockard H. Alan
Published: May 2009

✓ The authors report on the management of a patient in whom a fracture through an ossified transverse ligament had occurred, review the pertinent literature, and discuss the possible causes of ossification of the transverse ligament.
Simultaneous anterior—posterior approach for excision of malignant paraspinal tumor and subsequent reconstruction
Authors: Hasegawa Kazuhiro , Ogose Akira , Kobayashi Hiroto , Morita Tetsuro , Hirata Yasuharu
Published: May 2009

✓ In cases of primary malignant extradural tumors of the spine, the main goal of the surgery is en bloc resection and reconstruction of the spine. After placing the patient in the lateral position, an en bloc resection of a chondrosarcoma that arose from the right seventh rib head and invaded the adjacent vertebra was performed using a simultaneous anterior—posterior approach followed by spinal reconstruction. The technical details are reported. Paraspinal malignant tumors of the thoracic spine can be safely removed en bloc and the spine reconstructed using this approach.
Surgically treated lumbar disc disease in the pediatric population: an outcome study
Authors: Durham Susan R. , Sun Peter P. , Sutton Leslie N.
Published: May 2009

Object. This outcome study was undertaken to investigate the long-term results obtained in surgically treated pediatric patients with lumbar disc disease by using standardized medical outcome scales and clinical follow-up examination.

Methods. Twenty nine patients 17 years of age or younger underwent surgery between 1968 and 1998 for lumbar disc disease. The follow-up period ranged from 4 months to 30.5 years (mean 8.5 years). Outcome scores (health profiles) were generated using a standardized medical outcome scale, the Short Form health survey questionnaire (SF-36), and a condition-specific back pain outcome scale. Clinical follow-up data were obtained by telephone interview.

The health profile of the study population closely paralleled that of the normal population and was distinctly different from the health profile of adults with low-back pain. Only physical functioning, as measured by a scale of the SF-36, was found to be impaired in a subset of the study population. The rate of reoperation was 24% over the course of the follow-up period. In contrast to similar studies in adults, there were no identifiable predictive factors for either reoperation or poor outcome.

Conclusions. Lumbar disc disease in the pediatric population does not appear to lead to chronic complaints of back pain, and it does not appear to have a negative impact on overall health. This finding suggests that pediatric lumbar disc disease may be a separate entity distinct from adult lumbar disc disease, and therefore, the same conclusions regarding long-term outcome cannot be applied to the pediatric population.
Anatomical suitability of C1–2 transarticular screw placement in pediatric patients
Authors: Brockmeyer Douglas L. , York Julie E. , Apfelbaum Ronald I.
Published: May 2009

Object. Craniovertebral instability is a challenging problem in pediatric spinal surgery. Recently, C1–2 transarticular screw fixation has been used to assist in craniovertebral joint stabilization in pediatric patients. Currently there are no available data that define the anatomical suitability of this technique in the pediatric population. The authors report their experience in treating 31 pediatric patients with craniovertebral instability by using C1–2 transarticular screws.

Methods. From March 1992 to October 1998, 31 patients who were 16 years of age or younger with atlantooccipital or atlantoaxial instability, or both, were evaluated at our institution. There were 21 boys and 10 girls. Their ages ranged from 4 to 16 years (mean age 10.2 years). The most common causes of instability were os odontoideum (12 patients) and ligamentous laxity (eight patients). Six patients had undergone a total of nine previous attempts at posterior fusion while at outside institutions.

All patients underwent extensive preoperative radiological evaluation including fine-slice (1-mm) computerized tomography scanning with multiplanar reconstruction to evaluate the anatomy of the C1–2 joint space. Preoperatively, of the 62 possible C1–2 joint spaces in 31 patients, 55 sides (89%) were considered suitable for transarticular screw placement. In three patients the anatomy was considered unsuitable for bilateral screw placement. In three patients the anatomy was considered inadequate on one side. Fifty-five C1–2 transarticular screws were subsequently placed, and there were no neurological or vascular complications.

Conclusions. The authors conclude that C1–2 transarticular screw fixation is technically possible in a large proportion of pediatric patients with craniovertebral instability.
Fusion and instrumentation at C1–3 via the high anterior cervical approach
Authors: Vender John R. , Harrison Steven J. , McDonnell Dennis E.
Published: May 2009

Object. The high anterior cervical, retropharyngeal approach to the anterior foramen magnum and upper cervical spine is a favorable alternative to the transoral and posterolateral approaches, which both cause instability of the craniovertebral junction. Previously, such instability was corrected via an occipitocervical fusion during a separate surgical procedure.

Methods. Seven patients requiring C-2 corpectomy (foramen magnum meningioma [two patients], critical stenosis secondary to rheumatoid arthritis [two patients], C-2 fracture [two patients], and stenosis secondary to Rickets [one patient]) are presented. All patients underwent C1–3 fusion followed by instrumentation with a Caspar plate. A solid fusion was achieved in six patients. One patient experienced erosion of the anterior arch of C-1 requiring posterior stabilization.

Conclusions. Fusion and instrumentation at C1–3 can be performed safely and with minimal increase in surgical time. In selected patients, this may eliminate the need for an additional posterior procedure and maintain occipital—C1 mobility.
Indirect posterior reduction and fusion of the traumatic herniated disc by using a cervical pedicle screw system
Authors: Abumi Kuniyoshi , Shono Yasuhiro , Kotani Yoshihisa , Kaneda Kiyoshi
Published: May 2009

Object. In this study the authors retrospectively review 16 patients with traumatic disc herniation secondary to middle and lower cervical spine injuries who underwent a single posterior reduction and fusion procedure in which a cervical pedicle screw system was used. The study was undertaken to evaluate whether the procedure effectively reduced the disc herniation and whether it can be safely conducted without performing anterior decompressive surgery.

Methods. A total of 73 patients with middle and lower cervical spine injuries were identified. In 50 patients, pre- and postoperative magnetic resonance (MR) images were obtained, and disc herniation was defined as the presence of an extruded disc that deformed the thecal sac or nerve roots. Traumatic disc herniation was revealed in 16 patients (32%) who underwent a single posterior reduction/fusion procedure in which a cervical pedicle screw system was used. The average follow-up period was 4.25 years (2–6.25 years). In all patients the average kyphotic deformity was 18°, which was corrected to 0.7° lordosis postoperatively. Anterior translation was reduced from 8 to 0.7 mm. The preoperative disc height ratio of 63% (normal 100%) was improved to 104%. Preoperative MR images revealed traumatic disc herniation in all 16 patients; postsurgery, reduction or reversal of disc herniation was observed in all patients. Thecal sac and/or spinal cord compression had disappeared after indirect decompression was achieved using a posterior procedure. No additional decompressive procedures were required to remove residual herniated disc material. Preoperatively, four patients presented with cervical radiculopathy, 10 with myelopathy (eight incomplete and two complete), and two without neurological symptoms. At final follow up, complete recovery was observed in all four patients with radiculopathy and improvement of at least one Frankel grade was shown in six patients (60%) with myelopathy. There were no cases of neurological deterioration immediately after surgery or during the course of the follow-up period. In all patients solid bone union was demonstrated, and there were no implant-related complications.

Conclusions. Traumatic disc herniation may occur frequently in association with injury of the cervical spine. The incidence of traumatic disc herniation in our series was 32%. The cervical pedicle screw system allowed three-dimensional reduction of the injured cervical segment and reduction or reversal of a disc herniation. After surgery, compression of the thecal sac and/or spinal cord had disappeared. The cervical pedicle screw system provides effective and safe fixation of the cervical spine injury—related traumatic disc herniation, and the surgery can be performed safely in a single posteriorapproach procedure without need of additional anterior decompressive interventions.
Open-door laminoplasty for cervical stenotic myelopathy: surgical technique and neurophysiological monitoring
Authors: Roselli Romeo , Pompucci Angelo , Formica Francesco , Restuccia Domenico , Di Lazzaro Vincenzo , Valeriani Massimiliano , Scerrati Massimo
Published: May 2009

Object. A modified technique of open-door laminoplasty for cervical stenotic myelopathy (CSM) is described, and the role of evoked potential monitoring in selecting patients for surgery and evaluating results is discussed.

Methods. Between October 1992 and October 1996, 33 patients with CSM underwent open-door laminoplasty. After surgery, in 27 patients (81.8%) different levels of clinical improvement were demonstrated, and in five of them (15%) full recovery was observed. The Japanese Orthopaedic Association score increased from 5 to 12 (mean 9.8) preoperatively to 8 to 14 (mean 11.6) postoperatively. At 1-year follow up, the N13 cervical response was restored in nine (75%) of 12 patients with isolated presurgical abnormality and in 57.1% of those with combined abnormalities of both N13 and P14 response. Although significant clinical improvement was observed in 82% of the cases, in 24 of 33 patients MEP abnormalities persisted at least at one explored level.

Conclusions. Of several laminoplasty techniques, the one described here offers some advantages: preservation of biomechanical function of posterior muscular—ligamentous complex, prevention of laminar collapse, smaller degrees in reduction of range of cervical motion, stabilization of the spine with no postoperative malalignment, and maintenance of decompressive effect that avoids recurrent stenosis. Neurophysiological studies sometimes clarified neurological disorders that were only suspected on the basis of history and/or clinical examination, leading to early diagnosis.
Changes of bilateral palmar skin temperature in transthoracic endoscopic T-2 sympathectomy
Authors: Lu Kang , Liang Cheng-Loong , Lee Tao-Chen , Chen Han-Jung , Su Thung-Ming , Liliang Po-Chou
Published: May 2009

Object. Transthoracic endoscopic T-2 sympathectomy is currently the treatment of choice for palmar hyperhidrosis (PH). Intraoperative monitoring of palmar skin temperature (PST) is often used to assess the adequacy of sympathetic ablation. The aim of this study was to investigate the time course of PST changes during the operation and to determine factors involved in the sympathetic modulation of the palmar skin blood flow.

Methods. Eighty-one patients with PH underwent bilateral transthoracic endoscopic sympathectomy of T-2 in which continuous intraoperative PST monitoring was used. Palmar skin temperature data, recorded every 30 seconds throughout the operation, were plotted against time, and a graph of two PST curves was obtained in each case. A multiphasic curve pattern of great similarity was observed in nearly 70% of cases. Specific PST readings at different operative stages were collected and averaged for all cases. The trend of PST changes in response to different procedures during the operation was analyzed.

It was found that unilateral procedures caused simultaneous bilateral PST alterations. In almost all cases, bilateral PST was dramatically lowered when unilateral skin incision and intercostal muscle dissection were performed. The temperature remained low until the T-2 sympathectomy was finished on one side. In addition, unilateral T-2 sympathectomy induced synchronous elevation of bilateral PST. However, the ipsilateral response was significantly stronger than that on the contralateral side.

Conclusions. Although intraoperative monitoring of PST is a reliable guide for surgeons performing endoscopic transthoracic sympathectomy, it is important to realize that PST fluctuates at different stages during the operation and that surgical procedures themselves can significantly influence PST readings. The PST data recorded at specific time points, therefore, can be misleading in terms of accuracy and the completeness of ablation of the target sympathetic ganglia, especially when the sympathetic trunk or ganglia are anatomically aberrant.
Ventral foramen magnum meningiomas
Authors: Arnautović Kenan I. , Al-Mefty Ossama , Husain Muhammad
Published: May 2009

Object. Ventral foramen magnum meningiomas (VFMMs) are rare lesions that account for more than 3% of all meningiomas. These are among the most challenging of all meningiomas to treat. The authors comprehensively analyzed multiple features in a series of VFMMs.

Methods. A retrospective study was performed of 18 patients who harbored a meningioma in the ventral foramen magnum (mean follow-up period, 40 months) and underwent surgery via a transcondylar approach. Sixteen patients underwent surgery for the first time: 12 underwent gross-total (75%), two near-total (12.5%), and two subtotal (12.5%) tumor removal. The remaining two patients were treated for a recurrent tumor. After obtaining postoperative Karnofsky Performance Scale (KPS) scores at follow up, statistically significant improvement was demonstrated compared with the preoperative scores. The extent of surgery and higher preoperative KPS scores were variables that showed statistically significant favorable influence on outcome. Ninth and 10th cranial nerve deficits were the most common complications contributing to a prolonged hospital stay. There were no perioperative deaths. Four patients died during the follow-up period. The first patient died of multiple myeloma. The second patient, in whom surgery was performed to treat a recurrent tumor, died 3 years after the surgery of new tumor recurrence at the age of 80 years. The remaining two patients died 1.5 and 5 months postsurgery of pulmonary embolus and endocarditis, respectively.

Conclusions. Ventral foramen magnum meningiomas can be radically resected in a majority of patients, with frequent but transient morbidity caused by lower cranial nerve deficits. Radical removal of a recurrent tumor provides a relatively long, stable postoperative course. In patients presenting with a low KPS score a poor prognosis is demonstrated, and early diagnosis and treatment are recommended to avoid it.