bluuebunny/crossref_metadata_2025 huggingface dataset:
Foraminal deposition of calcium pyrophosphate dihydrate crystals in the thoracic spine: possible relationship with disc herniation and implications for surgical planning
Authors: Paolini Sergio , Ciappetta Pasquale , Guiducci Antonio , Principi Massimo , Missori Paolo , Delfini Roberto
Published: May 2009

✓ The authors report two cases of nodular calcium pyrophosphate dihydrate (CPPD) crystal deposition close to the thoracic neural foramen, which caused chronic radiculopathy. Preoperatively, the lesions were interpreted as calcified disc herniations. Both patients underwent surgery in which an extended transfacet pedicle-sparing approach was used. Incision of the posterior longitudinal ligament released soft degenerated material. In both cases, histological examination showed abundant degenerative debris along with CPPD crystals.

Spinal CPPD deposition is a comparatively rare disease that almost invariably involves the posterior aspect of the spinal canal, typically the ligamentum flavum. The exceptional foraminal location of the lesions reported here, combined with the surgical findings, indicated that the CPPD crystals were deposited on a laterally herniated disc fragment. A distinctive feature in both cases was the soft consistency of the resected tissue. The consistency of the disc material and the location of the lesion in the axial plane (that is, median compared with lateral) are key factors in determining the optimal surgical approach to thoracic disc herniations. In describing consistency, terms such as “calcified” and “hard” have been used interchangeably in the literature. In the cases reported here, what appeared on computerized tomography and magnetic resonance imaging studies to be densely calcified lesions were shown intraoperatively to be soft herniations.

The authors' experience underscores that not all densely calcified herniated discs are hard. Although detection of this discrepancy would have left surgical planning for the lateral disc herniations unchanged, it could have altered planning for centrally or centrolaterally located disc herniations.
Recurrent laryngeal nerve palsy during anterior cervical spine surgery: a prospective study
Authors: Jung Axel , Schramm Johannes , Lehnerdt Kai , Herberhold Claus
Published: May 2009

Object.Recurrent laryngeal nerve (RLN) palsy is a well-known complication of cervical spine surgery. Nearly all previous studies were performed without laryngoscopy in asymptomatic patients. This prospective study was undertaken to discern the true incidence of RLN palsy. Because not every RLN palsy is associated with hoarseness, the authors conducted a prospective study involving the use of pre- and postoperative laryngoscopy.

Methods.Prior to anterior cervical spine surgery preoperative indirect laryngoscopy was performed in 123 patients to evaluate the status of the vocal cords as a sign of function of the RLN. To assess postoperative status in 120 patients laryngoscopy was repeated, and in cases of vocal cord malfunction follow-up examination was conducted 3 months later.

In the group of 120 patients who attended follow-up examination, two (1.6%) had experienced a preoperative RLN palsy without hoarseness. Postoperatively the rate of clinically symptomatic RLN palsy was 8.3%, and the incidence of RLN palsy not associated with hoarseness (that is, clinically unapparent without laryngoscopy) was 15.9% (overall incidence 24.2%). At 3-month follow-up evaluation the rate had decreased to 2.5% in cases with hoarseness and 10.8% without hoarseness. Thus, the overall rate of early persisting RLN palsy was 11.3%.

Conclusions.Laryngoscopy revealed that the true incidence of initial and persisting RLN palsy after anterior cervical spine surgery was much higher than anticipated. Especially in cases without hoarseness this could be proven, but the initial incidence of hoarseness was higher than expected. Only one third of new RLN palsy cases could be detected without laryngoscopy. Resolution of hoarseness was approximately 70% in those with preoperative hoarseness. The true rate of RLN palsy underscores the necessity to reevaluate the surgery- and intubation-related techniques for anterior cervical spine surgery and to reassess the degree of presurgical patient counseling.
Surgical technique and results of endoscopic anterior spinal canal decompression
Authors: Beisse Rudolf , Mückley Thomas , Schmidt Meic H. , Hauschild Matthias , Büren Volker
Published: May 2009

Object.Decompression of the spinal canal in the management of thoracolumbar trauma is controversial, but many authors have advocated decompression in patients with severe canal compromise and neurological deficits. Anterior decompression, corpectomy, and fusion have been shown to be more reliable for spinal canal reconstruction than posterior procedures; however, traditional anterior-access procedures, thoracotomy, and thoracoabdominal approaches are associated with significant complications. Endoscopy-guided spinal access avoids causing these morbidities, but it has not been shown to yield equivalent results in spinal canal clearance. This study was conducted to demonstrate the effectiveness of endoscopic spinal canal decompression and reconstruction quantitatively by using pre- and postoperative computerized tomography (CT) scanning.

Methods.Thirty patients with thoracolumbar canal compromise underwent endoscopic anterior spinal canal decompression, interbody reconstruction, and stabilization for fractures (27 cases), and tumor, infection, and severe degenerative disc disease (one case each). The mean follow-up period was 42 months (range 24 months–6 years). Neurological examinations, Frankel grades, radiological studies, and intraoperative findings were prospectively collected.

Spinal canal clearance quantified on pre- and postoperative CT scans improved from 55 to 110%. A total of 25% of patients with complete paraplegia and 65% of those with incomplete neurological deficit improved neurologically. The complication rate was 16.7% and included one reintubation, two pleural effusions, one intercostal neuralgia, and one persistent lesion of the sympathetic chain.

Conclusions.The authors describe the endoscopic technique of anterior spinal canal decompression in the thoracolumbar spine. The morbidities associated with an open procedure were avoided, and excellent spinal canal clearance was accomplished as was associated neurological improvement.
Axial load—dependent cervical spinal alterations during simulated upright posture: a comparison of healthy controls and patients with cervical degenerative disease
Authors: Kimura Shinji , Hesselink John R. , Garfin Steven R. , Kawaji Yoichi , Hasegawa Kazuhiro , Hargens Alan R.
Published: May 2009

Object. The objectives of this study were to simulate the upright loading condition in the cervical spine by applying a new compression device during supine posture and to assess intervertebral angles and cross-sectional areas of the spinal cord and dural tube before and during axial compression.

Methods. A magnetic resonance (MR) imaging-compatible device was developed to create axial compression with the patient in the supine position. Lateral radiographs were obtained in upright and supine positions with an axial load of 0% (supine) and by applying a cervical compression device at 7, 10, and 13% of body weight (BW) in 18 control individuals and seven symptomatic patients with cervical degenerative disc disease (DDD). Additionally, cervical MR images acquired in 17 controls and 12 patients were compared before and during an axial load of 8.4% BW in terms of anteroposterior diameter and cross-sectional area of the dural sac.

The supine intervertebral angles with loads of 0, 7, 10, and 13% of the individuals' BW relative to upright posture were −8.1 ± 1.3, −2.3 ± 1.4, 1.3 ± 1.9, and 2.8 ± 2°, respectively. Subsequent axial force was interpolated as 8.9% of BW to simulate upright cervical spine alignment. Under an axial loading similar to that created by the upright posture, the dural sac narrowed at the C5–6 interspace in asymptomatic individuals and at the C6–7 interspace in patients with cervical DDD.

Conclusions. This cervical compression device may be a useful tool to simulate upright cervical spinal alignment. The results of this study help in understanding the pathophysiology of symptoms related to cervical degenerative disorders in upright posture.
Modern imaging of spinal tuberculosis
Authors: Joseffer Seth S. , Cooper Paul R.
Published: May 2009

✓ Spinal tuberculosis (Pott disease) is uncommon in developed countries. On imaging studies diagnosis of this lesion may not be considered or it might be mistaken for pyogenic osteomyelitis. Features most strongly indicative of a diagnosis of spinal tuberculosis are relative sparing of the disc space, large paraspinous abscesses, a thick rim of enhancement around the paraspinous and intraosseous abscesses, calcifications within the paraspinous collections, and a fragmentary pattern of osseous destruction. As the disease progresses, there is worsening of the osseous destruction, leading to collapse of the vertebral body and eventual progression to kyphotic deformity. Based on recent experience, the authors review the major imaging characteristics associated with spinal tuberculosis and describe the typical course of the disease as documented on plain radiographs, computerized tomography scans, and magnetic resonance images.
Atlantoaxial transarticular screw fixation: a review of surgical indications, fusion rate, complications, and lessons learned in 191 adult patients
Authors: Gluf Wayne M. , Schmidt Meic H. , Apfelbaum Ronald I.
Published: May 2009

Object. In this, the first of two articles regarding C1–2 transarticular screw fixation, the authors assessed the rate of fusion, surgery-related complications, and lessons learned after C1–2 transarticular screw fixation in an adult patient series.

Methods. The authors retrospectively reviewed 191 consecutive patients (107 women and 84 men; mean age 49.7 years, range 17–90 years) in whom at least one C1–2 transarticular screw was placed. Overall 353 transarticular screws were placed for trauma (85 patients), rheumatoid arthritis (63 patients), congenital anomaly (26 patients), os odontoideum (four patients), neoplasm (eight patients), and chronic cervical instability (five patients). Among these, 67 transarticular screws were placed in 36 patients as part of an occipitocervical construct. Seventeen patients had undergone 24 posterior C1–2 fusion attempts prior to referral. The mean follow-up period was 15.2 months (range 0.1–106.3 months).

Fusion was achieved in 98% of cases followed to commencement of fusion or for at least 24 months. The mean duration until fusion was 9.5 months (range 3–48 months). Complications occurred in 32 patients. Most were minor; however, five patients suffered vertebral artery (VA) injury. One bilateral VA injury resulted in patient death. The others did not result in any permanent neurological sequelae.

Conclusions. Based on this series, the authors have learned important lessons that can improve outcomes and safety. These include techniques to improve screw-related patient positioning, development of optimal instrumentation, improved screw materials and design, and defining the role for stereotactic navigation. Atlantoaxial transarticular screw fixation is highly effective in achieving fusion, and the complication rate is low when performed by properly trained surgeons.
Biomechanical comparison of C1–2 posterior fixation techniques
Authors: Hott Jonathan S. , Lynch James J. , Chamberlain Robert H. , Sonntag Volker K. H. , Crawford Neil R.
Published: May 2009

Object. In a nondestructive, repeated-measures in vitro flexibility experiment, the authors compared the acute stability of C1–2 after placement of C-1 lateral mass and C-2 pars interarticularis (LC1—PC2) instrumentation with that of C1–2 transarticular screw fixation.

Methods. The effect of C-1 laminectomy and C1–2 interspinous cable/graft fixation on LC1—PC2 stability was studied. Screw pullout strengths were also compared. Seven human cadaveric occiput—C3 specimens were loaded nondestructively with pure moments while measuring nonconstrained atlantoaxial motion. Specimens were tested with graft alone, LC1—PC2 alone, LC1—PC2 combined with C-1 laminectomy, and graft-augmented LC1—PC2. Interspinous cable/graft fixation significantly enhanced LC1—PC2 stability during extension. After C-1 laminectomy, the LC1—PC2 construct allowed increased motion during flexion and extension. There was no significant difference in lax zone or range of motion between LC1—PC2 fixation and transarticular screw fixation, but graft-assisted transarticular screws yielded a significantly smaller stiff zone during extension. The difference in pullout resistance between C-1 lateral mass screws and C-2 pars interarticularis screws was insignificant. The LC1—PC2 region restricted motion to within the normal range during all loading modes. Atlantal laminectomy reduced LC1—PC2 stability during flexion and extension.

Conclusions. The instrumentation-augmented LC1—PC2 construct performed biomechanically similarly to the C1–2 transarticular screw fixation. The LC1—PC2 construct resisted flexion, lateral bending, and axial rotation well. The weakness of the LC1—PC2 fixation in resisting extension can be overcome by adding an interspinous graft to the construct.
Biomechanical evaluation of a bioresorbable odontoid screw
Authors: Ames Christopher P. , Crawford Neil R. , Chamberlain Robert H. , Deshmukh Vivek , Sadikovic Belma , Sonntag Volker K. H.
Published: May 2009

Object.The authors tested the ability of a resorbable cannulated lag screw composed of a polylactide copolymer to repair Type II odontoid fractures. The resorbable screw was evaluated for its ability to restore strength and stiffness to the fractured odontoid process compared with traditional titanium screws.

Methods.Type II odontoid fractures were created in 14 human cadaveric C-2 vertebrae by applying a posterolaterally directed load and piston displacement was measured. Seven of these specimens were repaired using metal screws and seven were repaired using resorbable screws. Specimens were reinjured using the same mechanism as the initial fracture. Values of ultimate strength and stiffness during failure were statistically compared between metal and resorbable screws and between initial fracture and reinjury.

Conclusions.The stiffness and ultimate strength during initial fracture were significantly greater than those during reinjury in specimens repaired using resorbable screws or titanium screws (p < 0.001). The resorbable and titanium screws both restored 31% of the initial ultimate strength of the intact specimen (p = 0.95). The stiffness of the fractured odontoid process was restored to 15 and 23% of its initial value by repair with resorbable and metal screws, respectively (p = 0.07). The mode of failure in resorbable screws was usually breakage or bending, whereas that in metal screws was consistently cutout of the proximal shaft of the screw through the anterior C-2 vertebral body.
Multidirectional flexibility analysis of cervical artificial disc reconstruction: in vitro human cadaveric spine model
Authors: Kotani Yoshihisa , Cunningham Bryan W. , Abumi Kuniyoshi , Dmitriev Anton E. , Ito Manabu , Hu Niabin , Shikinami Yasuo , McAfee Paul C. , Minami Akio
Published: May 2009

Object. This in vitro experimental study was conducted to investigate the initial biomechanical effect of artificial intervertebral disc replacement in the cervical spine. The multidirectional flexibility of replaced and adjacent spinal segments were analyzed using a cadaveric cervical spine model.

Methods. The following three cervical reconstructions were sequentially performed at the C5–6 level after anterior discectomy in seven human cadaveric occipitocervical spines: anterior artificial disc replacement with a bioactive three-dimensional (3D) fabric disc (FD); anterior iliac bone graft; and anterior plate fixation with iliac bone graft. Six unconstrained pure moments were applied with a 6-df spine simulator, and 3D segmental motions at the operative and adjacent segments were measured with an optoelectronic motion measurement system. The 3D FD group demonstrated statistically equivalent ranges of motion (ROMs) when compared with intact values in axial rotation and lateral bending. The 45% increase in flexion—extension ROM was demonstrated in 3D FD group; however, neutral zone analysis did not reach statistical significance between the intact spine and 3D FD. The anterior iliac bone graft and iliac bone graft reconstructions demonstrated statistically lower ROMs when compared with 3D FD in all loading modes (p < 0.05). The adjacent-level ROMs of the 3D FD group demonstrated nearly physiological characteristics at upper and lower adjacent levels. Excellent stability at the interface was maintained during the whole testing without any device displacement and dislodgment.

Conclusions. The stand-alone cervical 3D FD demonstrated nearly physiological biomechanical characteristics at both operative and adjacent spinal segments in vitro, indicating an excellent clinical potential for cervical artificial disc replacement.
Central nervous system superficial siderosis following spinal surgery
Authors: Cohen-Gadol Aaron A. , Atkinson Patty P. , Krauss William E.
Published: May 2009

✓ Superficial siderosis of the central nervous system is a rare progressive disease associated with hemosiderin deposition on the leptomeninges of the neuraxis. In addition to tumors and vascular lesions, dural sleeve pseudomeningoceles caused by brachial plexus avulsion injury may be the bleeding source in this disease. The authors describe a patient who underwent anterior cervical spine surgery for spinal cord compression due to the ossification of posterior longitudinal ligament. The operation was complicated by a dural tear and subsequent psedomeningocele formation. Nine years later, this patient developed superficial siderosis. The possible mechanisms involved in the development of superficial siderosis in this patient will be discussed.
Subarachnoid pressure—dependent change in syrinx size in a patient with syringomyelia associated with adhesive arachnoiditis
Authors: Chang Han Soo , Joko Masahiro , Matsuo Naoki , Kim Sang Don , Nakagawa Hiroshi
Published: May 2009

✓ The pathophysiology of syringomyelia is still not well understood. Current prevailing theories involve the assumption that cerebrospinal fluid (CSF) flows into the syrinx from the subarachnoid space through the perivascular space of Virchow—Robin. Reported here is the case of a patient with syringomyelia in which this course is clearly contradicted.

This patient with a holocord syrinx associated with adhesive arachnoiditis was treated 3 years previously with insertion of a subarachnoid—peritoneal shunt and had recently experienced worsening myelopathy. On surgical exploration, the shunt system was functioning normally. The medium-pressure shunt valve was replaced with an adjustable valve with a higher closing pressure setting, thus increasing the CSF pressure in the subarachnoid space. Contrary to prevailing theories, this procedure markedly reduced the size of the syrinx.

This case provides direct evidence that the syrinx size is inversely related to subarachnoid CSF pressure and supports the hypothesis that the pressure gradient across the spinal cord parenchyma is the force that generates syringes in syringomyelia.
Topacheous gout as a rare cause of spinal stenosis in the lumbar region
Authors: Kelly Joseph , Lim Chris , Kamel Mahmoud , Keohane Catherine , O'Sullivan Michael
Published: May 2009

✓ Despite the fact that gout is a common metabolic disorder, because its involvement of the axial skeleton is rare the diagnosis is often delayed, even in patients with long-standing gout who present with neurological deficits. The authors report the case of a woman with a history of extensive gout, emphasizing the clinical, radiological, and pathological features of a lumbar spinal stenosis.
Thoracic aortic pseudoaneurysm after spine trauma in ankylosing spondylitis
Authors: Lifshutz Jason , Lidar Zvi , Maiman Dennis
Published: May 2009

✓ Ankylosing spondylitis (AS) is a rheumatic disease characterized by consolidation of the articulating surfaces and inflammation of the vertebral column. Because of its associated spine stiffness and secondary osteoporosis, patients with this disorder are at increased risk of vertebral fractures. Ankylosing spondylitis presents a significant challenge to spine surgeons because of its complex effects on the spine, extraarticular organ manifestations, and potential neurological and functional sequelae. Traumatic thoracic and lumbar spine injuries in this patient population may be associated with injury to the aorta either due to direct mechanical trauma or to blunt forces associated with the spine fracture. This complication and association is thought to be the result of pathophysiological changes that cause the aorta to become firmly adherent to the anterior longitudinal ligament.

The authors present a case of AS in a patient with a thoracic spine fracture and in whom a delayed thoracic aortic pseudoaneurysm ruptured. To the best of the authors' knowledge, only five cases of this complex condition have been reported since 1980. Recognition of the potential for aortic injury in patients with AS should prompt early investigation of the aorta in cases involving numerous fractures and assist in surgical planning to avoid this lethal injury.
The changing role for neurosurgeons and the treatment of spinal deformity
Authors: Johnson J. Patrick , Pashman Robert S. , Lauryssen Carl , Anand Neel , Regan John J. , Bray Robert S.
Published: May 2009

✓ Spinal deformity has classically and historically been studied by those in the discipline of orthopedic surgery. This may be attributable to the orthopedic interventionalists' experience with osseous fixation for long-bone and other skeletal fractures. Neurosurgeons have maintained a long-standing interest in complex cervical spinal disorders, and their interest in the larger field of complex spinal deformity has been expanding.

An understanding of spinal deformity disorders, biomechanics, bone biology, and metallurgy is necessary before clinical, teaching, and research activities can be undertaken within neurosurgery.

The authors describe basic and advanced concepts of spinal deformity management with cases to illustrate teaching points.
Operative management of metastatic and malignant primary subaxial cervical tumors
Authors: Bilsky Mark H. , Boakye Maxwell , Collignon Frederic , Kraus Dennis , Boland Patrick
Published: May 2009

Object.The authors describe the preoperative assessment, intraoperative strategies, and long-term outcomes in 41 consecutive patients who underwent spinal reconstruction after resection of subaxial cervical neoplasms.

Methods.Thirty-three tumors were metastatic and eight were primary. Preoperative studies included direct laryngoscopy and vertebral artery (VA) balloon occlusion tests in selected patients. Based on the tumor location, approaches included 12 anterior, 13 posterior, and 16 combined. All patients underwent aggressive intralesional resection and spinal reconstruction. In 12 patients, the VA was dissected from the periphery of the tumor, two cases of which required ligation. Fibula allograft and an anterior rigid plate fixation were most commonly used for anterior reconstruction. Posterior reconstruction was initially performed using lateral mass plates (LMPs) in 13 patients and screw/rod systems in the remaining patients.

At follow up, pain level improved to mild or was absent in 39 patients (95%) who had presented with moderate or severe pain. The American Spinal Injury Association (ASIA) Scale scores were stable in 25 patients who presented with ASIA Score E and improved in 14 patients (88%) who presented with ASIA Score B, C, or D. Functional radiculopathy significantly improved in 16 (94%) of 17 patients.

Complications occurred in 10 patients (24%) and included three fixation failures requiring revision. Two fixation failures involved cervical LMP screw pullout. The overall mean survival duration was 8.6 months for patients with metastatic tumors and 33.4 months for primary tumors.

Conclusions.Surgery for the treatment of subaxial spine neoplasms is effective for relieving pain, encouraging functional nerve root recovery, and preserving spinal cord function with acceptable complication rates.
Outcome after lumbar sequestrectomy compared with microdiscectomy: a prospective randomized study
Authors: Thomé Claudius , Barth Martin , Scharf Johann , Schmiedek Peter
Published: May 2009

Object. Microdiscectomy currently constitutes the standard treatment for herniated lumbar discs. Although limiting surgery to excision of fragments has occasionally been suggested, prospective data are lacking. Therefore, the objective of this study was to compare early outcome and recurrence rates after sequestrectomy and microdiscectomy.

Methods. Eighty-four consecutive patients 60 years of age or younger who harbored free, subligamentary, or transanular herniated lumbar discs refractory to conservative treatment were randomized to one of two treatment groups. Intraoperative parameters and findings were documented as well as pre- and postoperative symptoms such as pain, Patient Satisfaction Index (PSI), Prolo Scale score, and Short Form (SF)—36 subscale results. Follow up of at least 12 months was available in 73 patients (87%).

Preoperative intergroup symptoms did not differ significantly. Surgery was significantly shorter in the sequestrectomy-treated group. Overall, low-back pain and sciatica were drastically reduced in both groups and most sensorimotor deficits improved. At 4 to 6 months, SF-36 subscales and PSI scores showed a trend in favor of sequestrectomy, leaving 3% of patients unsatisfied compared with 18% of those treated with discectomy. Outcome according to the Prolo Scale was good or excellent in 76% of discectomy-treated patients and 92% of sequestrectomy-treated patients. Reherniation occurred in four patients after discectomy (10%) and two patients after sequestrectomy (5%) within 18 months.

Conclusions. Sequestrectomy does not seem to entail a higher rate of early recurrences compared with microdiscectomy. Analysis of early outcome demonstrated a trend toward superior results when sequestrectomy is performed. Although long-term follow-up data are mandatory, sequestrectomy may be an advantageous alternative to standard microdiscectomy.
Long-term outcome in 132 consecutive patients after posterior internal fixation and fusion for Grade I and II isthmic spondylolisthesis
Authors: Wenger Markus , Sapio Nicola , Markwalder Thomas-Marc
Published: May 2009

Object.The authors assessed the late outcome of patients with Meyerding Grade I and II isthmic spondylolisthesis (IS) who underwent posterior instrumentation and posterolateral fusion (PLF). Decompression and posterior internal fixation with PLF is the classic surgical treatment for painful low-grade IS. Nevertheless, outcome data are scarce and of limited value mainly because they represent small numbers of patients, short follow-up periods, or both.

Methods.The authors obtained data in the cases of 132 consecutive adult patients (mean age 40.6 years, range 15.2–69.9 years) with IS who underwent treatment between 1984 and 2003. Assessment involved analysis of responses to mailed questionnaires, clinical charts and, in cases in which unsatisfactory results were suspected, results of clinical reevaluations. Spondylolisthesis was present at L3–4 in three patients, L4–5 in 14, L3–4 in one, L3–5 in one, L5—S1 in 113, and S1–2 in one. Signs and symptoms included back and leg pain (65.3%), leg pain alone (26.3%), back pain alone (8.4%), and neurological dysfunction (18%).

At a mean follow-up duration of 9.9 years (range 0.5–19.4 years), favorable results were reported for back and leg pain in 91.7 and 87.1% of patients, respectively. The mean visual analog scale scores were 2.13 for back and 1.59 for leg pain. Eighty-four patients resumed full- or part-time work, and 56.8% were capable of performing housework more easily. In 45.5% of the patients analgesic medications were not required, and 43.9% required them sporadically. The majority (63.6%) of patients reported they would undergo surgery again and recommended it to others. Thirteen (9.9%) suffered adjacent-segment morbidity, and in seven (5.3%) pseudarthrosis was documented. There were two deep and one superficial infections (2.3%).

Conclusions.Posterior instrumentation and PLF, with possible neurodecompression, yielded favorable long-term results in this retrospective study of 132 patients with low-grade IS.
Unilateral progressive alterations in the lumbar spine: a biomechanical study
Authors: Tender Gabriel C. , Kutz Scott , Baratta Richard , Voorhies Rand M.
Published: May 2009

Object. Lumbar radiculopathy secondary to foraminal stenosis can be treated by unilateral removal of the overlying pars interarticularis. The main concern after this procedure is spinal stability. In this study the authors evaluate the biomechanical behavior of the lumbar spine under torsional loading after unilateral progressive alterations, including resection of the pars.

Methods. Six human cadaveric L5—sacrum functional spinal units were tested while intact and then after the following sequential unilateral alterations: excision of the pars, capsulectomy, facetectomy, and discectomy. Specimens were tested in rotation by using a biomechanical testing machine, with an axial load of 280 N and torques of ± 7.5 Nm. The specimens remained in the machine throughout testing, and the angular displacements were recorded after each set of trials.

No statistically significant difference in any of the measured parameters was found between intact spines and those undergoing resection of the pars. For positive displacement (toward the side of the lesion), a significant difference from the intact condition was found after facetectomy and discectomy. For overall displacement (range of motion), spines treated with capsulectomy, facetectomy, and discectomy were significantly different from those in the intact condition.

Conclusions. Unilateral removal of the pars interarticularis does not increase spinal mobility in a statistically significant fashion. The clinical implication is that the spine may not become acutely unstable after unilateral resection of the pars.
Effects of epidural hypothermic saline infusion on locomotor outcome and tissue preservation after moderate thoracic spinal cord contusion in rats
Authors: Casas Carlos E. , Herrera Loren P. , Prusmack Chad , Ruenes Gladys , Marcillo Alexander , Guest James D.
Published: May 2009

Object.Regionally delivered hypothermia has advantages over systemic hypothermia for clinical application following spinal cord injury (SCI). The effects of local hypothermia on tissue sparing, neuronal preservation, and locomotor outcome were studied in a moderate thoracic spinal cord contusion model.

Methods.Rats were randomized to four treatment groups and data were collected and analyzed in a blinded fashion. Chilled saline was perfused into the epidural space 30 minutes postcontusion to achieve the following epidural temperatures: 24 ± 2.3°C (16 rats), 30 ± 2.4°C (13 rats), and 35 ± 0.9°C (13 rats). Hypothermia was continued for 3 hours when a 45-minute period of rewarming was instituted. In a fourth group a moderate contusion only was induced in 14 animals. Rectal (core) and T9–10 (epidural) temperatures were measured continuously. Locomotor testing, using the Basso-Beattie-Bresnahan (Ba-Be-Br) scale, was performed for 6 weeks, and rats were videotaped for subsequent analysis. The lesion/preserved tissue ratio was calculated throughout the entire lesion cavity and the total lesion, spinal cord, and spared tissue volumes were determined. The rostral and caudal extent of gray matter loss was also measured. At 6 weeks locomotor recovery was similar in all groups (mean Ba-Be-Br Scale scores 14.88 ± 3.71, 14.83 ± 2.81, 14.50 ± 2.24, and 14.07 ± 2.39 [p = 0.77] for all four groups, respectively). No significant differences in spared tissue volumes were found when control and treatment groups were compared, but gray matter preservation was reduced in the infusion-treated groups.

Conclusions.Regional cooling applied 30 minutes after a moderate contusive SCI was not beneficial in terms of tissue sparing, neuronal preservation, or locomotor outcome. This method of cooling may reduce blood flow in the injured spinal cord and exacerbate secondary injury.
Spinal cord injury induction of lesional expression of profibrotic and angiogenic connective tissue growth factor confined to reactive astrocytes, invading fibroblasts and endothelial cells
Authors: Conrad Sabine , Schluesener Hermann J. , Adibzahdeh Mehdi , Schwab Jan M.
Published: May 2009

Object. The glial scar composed of astrogliosis and extracellular matrix deposition represents a major impediment to axonal regeneration. The authors investigated the role of a novel profibrotic and angiogenic peptide connective tissue growth factor (CTGF [Hcs24/IGFBP-r2P]) in glial scar formation following spinal cord injury (SCI) in rats.

Methods. The effects of SCI on CTGF expression during glial scar maturation 1 day to 1 month post-SCI were investigated using fluorescein-activated cell sorter (FACS) immunohistochemical analysis; these findings were compared with those obtained in sham-operated (control) spinal cords.

The CTGF-positive cells accumulated at the spinal cord lesion site (p < 0.0001) corresponding to areas of glial scar formation. In the perilesional rim, CTGF expression was confined to invading vimentin-positive, glial fibrillary acidic protein (GFAP)—negative fibroblastoid cells, endothelial and smooth-muscle cells of laminin-positive vessels, and GFAP-positive reactive astrocytes. The CTGF-positive astrocytes coexpressed the activation-associated intermediate filaments nestin, vimentin (> 80%), and mesenchymal scar component fibronectin (50%).

Conclusions. The restricted accumulation of CTGF-reactive astrocytes and CTGF-positive fibroblastoid cells lining the laminin-positive basal neolamina suggests participation of these cells in scar formation. In addition, perilesional upregulation of endothelial and smooth-muscle CTGF expression points to a role in blood—brain barrier function modulating edema-induced secondary damage.
Anatomical landmarks for the lumbar plexus on the posterior abdominal wall
Authors: Tubbs R. Shane , Salter E. George , Wellons John C. , Blount Jeffrey P. , Oakes W. Jerry
Published: May 2009

Object. Reports describing surgical landmarks with which to identify the branches of the lumbar plexus found on the posterior abdominal wall are lacking in the English-language literature.

Methods. The authors examined 22 sides from six female and five male cadavers. Measurements were made between the branches of the lumbar plexus and various bone landmarks such as the midline vertebral bodies, supracristal plane—a horizontal line connecting the superior-most aspect of the left and right iliac crests approximating the L4–5 vertebrae—and anterior superior iliac spine (ASIS).

The mean distances from the midline and as they emerged through or lateral to the psoas major muscle to the subcostal, iliohypogastric, ilioinguinal, lateral femoral cutaneous, genitofemoral, and femoral nerves, were 5.5, 6, 6.5, 6, 4.5, and 4.5 cm, respectively. At a vertical line through the midpoint between the ASIS and the midline, the subcostal, iliohypogastric, and ilioinguinal nerves were superior to the supracristal plane at mean distances of 8, 4, and 5 cm, respectively. Inferior to the supracristal plane and in a vertical line through a midpoint between the ASIS and the midline, the lateral femoral and femoral nerves were found to have mean distances of 5 and 5.5 cm, respectively. The obturator nerve had a mean distance of 3 cm lateral to the midline. Additionally, the lateral femoral cutaneous nerve had a mean distance of 1.5 cm inferomedial to the ASIS.

Conclusions. A good working knowledge of the locations and anatomy of the nerves of the lumbar plexus on the posterior abdominal wall is necessary for the surgeon who operates in this region. The measurements provided herein will aid the surgeon who wishes to expose or avoid these nerves, thus precluding injury.
Biomechanical studies of an artificial disc implant in the human cadaveric spine
Authors: Hitchon Patrick W. , Eichholz Kurt , Barry Christopher , Rubenbauer Paige , Ingalhalikar Aditya , Nakamura Satoshi , Follett Kenneth , Lim Tae Hong , Torner James
Published: May 2009

Object. The authors compared the biomechanical performance of the human cadaveric spine implanted with a metallic ball-and-cup artificial disc at L4–5 with the spine's intact state and after anterior discectomy.

Methods. Seven human L2—S1 cadaveric spines were mounted on a biomechanical testing frame. Pure moments of 0, 1.5, 3.0, 4.5, and 6.0 Nm were applied to the spine at L-2 in six degrees of motion (flexion, extension, right and left lateral bending, and right and left axial rotation). The spines were tested in the intact state as well as after anterior L4–5 discectomy. The Maverick disc was implanted in the discectomy defect, and load testing was repeated.

The artificial disc created greater rigidity for the spine than was present after discectomy, and the spine performed biomechanically in a manner comparable with the intact state.

Conclusions. The results indicate that in an in vitro setting, this model of artificial disc stabilizes the spine after discectomy, restoring motion comparable with that of the intact state.
Paragangliomas of the lumbar region
Authors: Gelabert-González Miguel
Published: May 2009

✓ The author reports two cases of cauda equina paraganglioma (CEP) and provides a review of all previously published cases. The current radiological, neurosurgical, and pathological literature on this rare tumor is also reviewed.
Presacral ganglioneuromas
Authors: Modha Ashok , Paty Philip , Bilsky Mark H.
Published: May 2009

✓ Ganglioneuromas are rare, benign, slow-growing tumors belonging to the neuroblastoma group. The authors describe the presentation and treatment of five consecutive patients who presented with presacral ganglioneuromas; these cases represent the largest series to date. A review of the literature is also performed.
Atlantooccipital transarticular screw fixation for the treatment of traumatic occipitoatlantal dislocation
Authors: Feiz-Erfan Iman , Gonzalez L. Fernando , A. Dickman Curtis
Published: May 2009

✓ The authors describe a new technique of internal atlantooccipital screw fixation involving posterior wiring and fusion for the treatment of traumatic atlantooccipital dislocation, which was performed in a 17-year-old male patient involved in a motor vehicle accident and who suffered from atlantooccipital dislocation without neurological injury. At the 6-month follow-up examination, the patient was neurologically intact with a solid occipitocervical fusion and full range of motion of the neck.
Technical advantages of an ultrasonic bone curette in spinal surgery
Authors: Nakagawa Hiroshi , Kim Sang-Don , Mizuno Junichi , Ohara Yukoh , Ito Kiyoshi
Published: May 2009

Object.The authors discuss the safety and efficacy of an ultrasonic bone curette in various spinal surgeries and report its advantages in clinical application.

Methods.Between April 2002 and September 2003, 76 patients with various spinal diseases (29 cervical, five thoracic, 40 lumbosacral, and two foramen magnum regions) were treated microsurgically by using a Sonopet ultrasonic bone curette with longitudinal and torsional tips and lightweight handpieces. The operations were performed successfully and the device was easy to handle. There were no instrument-related complications or -induced damage to any structure even when removing osseous spurs or ossified lesions near the dura mater, nerves, and vessels.

Conclusions.The ultrasonic curette is a useful instrument for procedures performed near the dura mater or other neural tissue without excessive heat production or mechanical injury. This device is recommended for various spinal surgeries in addition to high-speed drills or other tools.
Percutaneous vertebroplasty and kyphoplasty performed at a cancer center: refuting proposed contraindications
Authors: Hentschel Stephen J. , Burton Allen W. , Fourney Daryl R. , Rhines Laurence D. , Mendel Ehud
Published: May 2009

Object. The purpose of this study was to examine a group of patients with cancer who underwent a vertebroplasty or a kyphoplasty for a vertebral body (VB) fracture, even though the procedure may have been considered contraindicated based on previous reports in the literature.

Methods. The electronic database maintained by the Departments of Neurosurgery and Anesthesiology—Pain Management at the University of Texas M. D. Anderson Cancer Center was searched for patients who underwent vertebroplasty or kyphoplasty between January 2001 and July 2003. The criteria defining a contraindicated procedure were based on a review of the literature. Group I consisted of patients who did not undergo a contraindicated vertebroplasty or kyphoplasty, whereas Group II consisted of patients who underwent one of these procedures even though it may have been considered contraindicated.

There were 53 patients with fractures at 132 levels who met the criteria for the study. Of these, 17 patients with fractures at 18 levels (14% of total) were considered to have undergone a contraindicated vertebroplasty or kyphoplasty (Group II). There were 12 complications (11%) in the 114 levels in Group I and seven complications (39%) in the 18 levels in Group II (p = 0.03). The most common complication was cement extrusion from the anterior VB that did not involve the venous system. No patient required an open surgical procedure to remove extruded cement.

Conclusions. Vertebroplasty and kyphoplasty appear to be safe and effective in the setting of severe back pain caused by VB fracture that is unresponsive to other therapies, even in the presence of relative contraindications to the procedures.
New treatment of lumbar disc herniation involving 5-hydroxytryptamine2A receptor inhibitor: a randomized controlled trial
Authors: Kanayama Masahiro , Hashimoto Tomoyuki , Shigenobu Keiichi , Oha Fumihiro , Yamane Shigeru
Published: May 2009

Object.Serotonin or 5-hydroxytryptamine (5-HT) is a chemical mediator associated with nucleus pulposus—induced radiculopathy. Inhibition of 5-HT receptors may potentially alleviate symptoms in patients with lumbar disc herniation. This prospective randomized controlled study was performed to evaluate the efficacy of the 5-HT2Areceptor inhibitor in the treatment of symptomatic lumbar disc herniation.

Methods.Forty patients with sciatica due to L4–5 or L5—S1 disc herniation were randomly allocated to treatment with the 5-HT2Ainhibitor (sarpogrelate 300 mg/day) or nonsteroidal antiinflammatory drugs (NSAIDs; diclofenac 75 mg/day). Low-back pain, leg pain, and numbness were evaluated using a visual analog scale (VAS) before and after a 2-week course of treatment. The patients received only allocated medicine during the 2-week regimen and were thereafter allowed to choose any treatment options depending on their residual symptoms. One-year clinical outcomes were assessed based on the rates of additional medical interventions.

The mean VAS score improvements in the 5-HT2Aand NSAID groups were 33 and 46% for low-back pain, 32 and 32% for leg pain, and 35 and 22% for leg numbness, respectively. After the 2-week regimen, no additional medical interventions were required in 50% of 5-HT2A—treated patients and 15% of those receiving NSAIDs. Epidural or nerve root block procedures were performed in 35% of the 5-HT2Agroup and 45% of the NSAID group. Surgery was required in 20% of the 5-HT2Agroup and 30% of the NSAID group patients.

Conclusions.The current study provided evidence that the efficacy of the 5-HT2Ainhibitor was comparable with that of NSAID therapy for lumbar disc herniation. The 5-HT2Ainhibitor has the potential to alleviate symptoms in patients with lumbar disc herniation.
Spinal extradural schwannoma
Authors: Celli Paolo , Trillò Giuseppe , Ferrante Luigi
Published: May 2009

Object. The authors endeavor to define the clinical and surgery-related profile of spinal nerve sheath tumors located in the extradural space outside both the dural sac and, apparently, the nerve roots' sleeve.

Methods. A series of 24 extradural schwannomas was retrospectively selected after reviewing the notes of spinal nerve sheath tumors surgically treated at La Sapienza University of Rome. Clinical data, tumor-related characteristics, and outcome were analyzed.

Women predominantly harbored these tumors. On admission sensory nerve root dysfunction was infrequently reported, whereas pyramidal tract deficits were often present. The tumor, generally large, was most frequently located in the intermediate thoracic segments and high cervical region; only one was reported in the lumbosacral region. Considerable erosion of vertebral bodies was reported in almost one third of the cases. In four patients eloquent nerve roots, that of C-5 in three and that of S-1 in one, were involved with the tumor. Radical tumor resection, with preservation of the nerve roots, was possible in several cases, whereas in two patients manipulation and resection of the C-5 root produced transient and permanent, respectively, root palsy. At follow-up examination patients for whom walking was impossible before surgery were now able to walk.

Conclusions. Extradural schwannomas can be distinguished from other nerve sheath tumors growing inside the spinal canal by their clinicoradiological features and unlikely nerve root origin. After surgery, recovery from pyramidal tract deficits, even severe, is noteworthy; in the authors' experience, however, resection of an involved appendicular root is more likely to result in a permanent and significant radicular deficit.
Spinal nerve root ganglionitis as a cause of disc herniation
Authors: Roser Florian , Ritz Rainer , Morgalla Matthias , Tatagiba Marcos , Bornemann Antje
Published: May 2009

✓ The authors report on a patient in whom monoradicular pain was caused by ganglionitis of a spinal nerve. Neuroimaging and intraoperative findings identified what were thought to be tumorlike changes in the affected nerve root. The neuropathological examination, however, revealed typical signs of ganglionitis. This rare inflammation usually appears with viral infections, as part of paraneoplastic symptoms, or in the presence of Sjögren disease. Because all of these differential diagnoses were negative in the treated patient, chronic nerve root compression due to disc herniation was suspected as the causative factor for the spinal ganglionitis.
Charcot arthropathy in relation to autonomic dysreflexia in spinal cord injury
Authors: Mohit A. Alex , Mirza Sohail , James Jennifer , Goodkin Robert
Published: May 2009

✓ Charcot spinal arthropathy has been described as a late complication of spinal cord injury. In patients with these injuries in whom the spine below the level of injury is insensate, joint trauma can progress until spinal instability ensues. The authors describe the case of a 50-year-old man with complete C-8 tetraplegia who experienced a 4-month history of episodic severe headaches, profuse sweating over his face and arms, and episodic severe hypertension in addition to a “grinding” sensation in the lower back. Charcot arthropathy at the T11–12 levels with pathological mobility was demonstrated on neuroimaging. Intraoperatively, a complete spinal cord transection was identified. Anterior and posterior thoracolumbar fusion across the mobile segment resulted in complete amelioration of signs and symptoms of autonomic dysreflexia. This entity, a common condition in the setting of spinal cord injury, has many triggers. Definitive treatment is targeted at the removal of the underlying cause. As demonstrated here, Charcot spinal arthropathy can act as a powerful trigger for induction of autonomic dysreflexia. Treatment of the associated spinal instability resulted in eradication of all signs and symptoms of the dysreflexia.