bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical removal of epidural and intradural polymethylmethacrylate extravasation complicating percutaneous vertebroplasty for an osteoporotic lumbar compression fracture
Authors: Shapiro Scott , Abel Todd , Purvines Scott
Published: May 2009

✓ The authors report the case of patient with a lumbar vertebral body osteoporotic compression fracture who underwent percutaneous transpedicular polymethylmethacrylate (PMMA)—assisted vertebroplasty in whom extravasation of the cement into the spinal canal caused immediate neurological deterioration.

Lateral lumbar radiography and computerized tomography scanning demonstrated the presence of intraspinal PMMA. The patient suffered severe low-back pain, left-sided sciatica, and profound left L2–4 distribution weakness and numbness. She underwent immediate L-2 laminectomy, the extra- and intradural PMMA was removed, and instrumentation-assisted lateral mass fusion was performed. The patient recovered without incident and her neurological deficit improved.

Extravasation of cement into the spinal canal, neural foramen, paraspinal veins, or disc space has been reported in 11 to 73% of percutaneous transpedicular PMMA-assisted vertebroplasty procedures. It is disturbing that more than one group of authors has documented symptomatic spinal canal PMMA extravasation and that the patients were left severely handicapped because of a stated fear that surgery to remove the cement would be difficult and make them worse. The results achieved in this case refute that published notion. It is important to document that decompressive surgery and PMMA removal from the spinal canal are easy and can lead to immediate neurological improvement. With the increasing popularity of percutaneous transpedicular PMMA-assisted vertebroplasty, the authors suspect that more of these cases will be seen.
Failed anterior cervical foraminotomy
Authors: Hacker Robert J. , Miller Christopher G.
Published: May 2009

Object. Anterior cervical foraminotomy has been advocated as a procedure that preserves the motion segment while treating radiculopathy due to degenerative cervical disc disease. Because the medical literature contains no long-term follow up or randomized studies related to this procedure, the authors reviewed their results, specifically examining cases of failure to determine the efficacy of the approach.

Methods. The authors identified 23 patients in whom unilateral cervical radiculopathy due to degenerative cervical disc disease was refractory to conservative therapy and in whom anterior cervical foraminotomy was performed between 1998 and 2000. The procedure involves ipsilateral exposure, microsurgical removal of the uncovertebral joint to identify the nerve root, and partial removal of the lateral anulus and or disc fragments. Data in those patients who underwent reoperation(s) were reviewed specifically for the procedure type, interval between index procedure and reoperation, and whether multiple procedures were performed. Of the 23 patients, 30% required at least one additional procedure. A good or excellent outcome at last follow-up examination was achieved in only 12 patients.

Conclusions. In the current study the authors found a reoperation rate that is considerably higher than that in most series of anterior cervical surgery for radiculopathy. The presumed benefit of anterior cervical foraminotomy is preservation of the disc interspace; however, in this study, a significant number of patients failed to experience a satisfying outcome. Currently the authors do not recommend anterior cervical foraminotomy as a stand-alone procedure.
Cervical laminoplasty: evaluation of bone bonding of a high porosity hydroxyapatite spacer
Authors: Iguchi Tetsuhiro , Kanemura Aritetsu , Kurihara Akira , Kasahara Koichi , Yoshiya Shinichi , Doita Minoru , Nishida Kotaro
Published: May 2009

Object. The purpose of this study was to evaluate the usefulness of a high-porosity hydroxyapatite (HA) spacer in cervical laminoplasty. Bone—spacer bonding rates, complications associated with the implant, and factors related to bone bonding were examined.

Methods. The authors evaluated 33 consecutive patients with cervical myelopathy who underwent high-porosity HA spacer—assisted laminoplasty and were followed for at least 1 year (mean 30 months). The results of bone—spacer bonding of the 147 implants were evaluated using computerized tomography (CT) scanning. The symptoms significantly improved in 30 patients. No difference in results was detected between patients with cervical spondylosis and those with ossification of posterior longitudinal ligament. Breakage of seven spacers occurred in four patients without causing neck pain or neurological deficits. There were no other HA spacer—related complications. The spacers became rigidly bound to bone in 61% of the cases, and bone regrowth developed around the spacer in 91%. The rate of bone—spacer bonding increased over time, and the CT-documented attenuation value (Hounsfield unit) of the spacer adjacent to the bone—spacer junction in the group in which union occurred was significantly higher than in the nonunion group.

Conclusions. High-porosity HA spacer—augmented laminoplasty produced good bonding-related results. Bone bonding continued to progress 1 year after surgery, indicating the good osteoconductive capability of high-porosity HA. To avoid breakage of a spacer, a minimum 7-mm distance between spacers is necessary.
Implantation of an empty carbon fiber composite frame cage after single-level anterior cervical discectomy in the treatment of cervical disc herniation: preliminary results
Authors: Payer Michael , May Daniel , Reverdin Alain , Tessitore Enrico
Published: May 2009

Object. The authors sought to evaluate retrospectively the radiological and clinical outcome of anterior cervical discectomy followed by implantation of an empty carbon fiber composite frame cage (CFCF) in the treatment of patients with cervical disc herniation and monoradiculopathy.

Methods. Twenty-five consecutive patients (12 men, 13 women, mean age 45 years) with monoradiculopathy due to cervical disc herniation were treated by anterior cervical discectomy followed by implantation of an empty CFCF cage. On lateral flexion—extension radiographs segmental stability at a mean follow up of 14 months (range 5–31 months) was demonstrated in all 25 patients, and bone fusion was documented in 24 of 25 patients. The mean anterior intervertebral body height was 3.4 mm preoperatively and 3.8 mm at follow up in 20 patients. In these patients the mean segmental angle (angle between lower endplate of lower and upper vertebra) was 0.9° preoperatively and 3.1° at follow up. In the remaining five patients preoperative images were not retrievable.

Self-scored neck pain based on a visual analog scale (1, minimum; 10, maximum) changed from a preoperative average of 5.6 to an average of 2 at follow up; radicular pain was reduced from 7.7 to 2.1 postoperatively. Analysis of the SF12 questionnaires showed a significant improvement in both the physical capacity score (preoperative mean 32.4 points; follow up 46 points) and the mental capacity score (preoperative mean 45.8 points; follow up 57.5 points).

Conclusions. Implantation of an empty CFCF cage in the treatment of cervical disc herniation and monoradiculopathy avoids donor site morbidity associated with autologous bone grafting as well as the use of any supplementary material inside the cage. Restoration or maintenance of intervertebral height and thus segmental lordosis and a very high rate of segmental stability and fusion are achieved using this technique.
Risk factors for surgical site infection in spinal surgery
Authors: Olsen Margaret A. , Mayfield Jennie , Lauryssen Carl , Polish Louis B. , Jones Marilyn , Vest Joshua , Fraser Victoria J.
Published: May 2009

Object. The objective of this study was to identify specific independent risk factors for surgical site infections (SSIs) occurring after laminectomy or spinal fusion.

Methods. The authors performed a retrospective case-control study of data obtained in patients between 1996 and 1999 who had undergone laminectomy and/or spinal fusion. Forty-one patients with SSI or meningitis were identified, and data were compared with those acquired in 178 uninfected control patients. Risk factors for SSI were determined using univariate analyses and multivariate logistic regression.

The spinal surgery—related SSI rate (incisional and organ space) during the 4-year study period was 2.8%. Independent risk factors for SSI identified by multivariate analysis were postoperative incontinence (odds ratio [OR] 8.2, 95% confidence interval [CI] 2.9–22.8), posterior approach (OR 8.2, 95% CI 2–33.5), procedure for tumor resection (OR 6.2, 95% CI 1.7–22.3), and morbid obesity (OR 5.2, 95% CI 1.9–14.2). In patients with SSI the postoperative hospital length of stay was significantly longer than that in uninfected patients (median 6 and 3 days, respectively; p < 0.001) and were readmitted to the hospital for a median additional 6 days for treatment of their infection. Repeated surgery due to the infection was required in the majority (73%) of infected patients.

Conclusions. Postoperative incontinence, posterior approach, surgery for tumor resection, and morbid obesity were independent risk factors predictive of SSI following spinal surgery. Interventions to reduce the risk for these potentially devastating infections need to be developed.
Results of preoperative embolization for metastatic spinal neoplasms
Authors: Prabhu Vikram C. , Bilsky Mark H. , Jambhekar Kedar , Panageas Katherine S. , Boland Patrick J. , Lis Eric , Heier Linda , Nelson P. Kim
Published: May 2009

Object. Arterial embolization reduces blood loss in patients undergoing surgery for hypervascular spinal tumors. The objectives of this study were twofold: 1) to evaluate the role of magnetic resonance (MR) imaging in predicting tumor vascularity and 2) to assess the effectiveness of preoperative embolization in devascularizing these tumors.

Methods. Fifty-one patients with metastatic spinal neoplasms underwent angiography, preoperative embolization, and excision of the lesion between 1995 and 2000. The MR imaging studies were correlated with tumor vascularity on angiograms. Embolization was angiographically graded on a five-point scale ranging from no embolization (Grade A) to total embolization (Grade E). The embolization grade was correlated with intraoperative blood loss.

The mean age was 57 years, the male/female ratio was 1.2:1, and back pain was present in all patients. Metastatic renal cell carcinoma (30 cases) and thoracic spine involvement (33 cases) were most frequent. The positive predictive value of MR imaging in determining tumor vascularity was 77%, whereas the negative predictive value was 21%. Total embolization (Grade E) was achieved in 34 patients. A shared vascular pedicle between a radiculomedullary artery (RMA) and a tumor diminished the likelihood of complete embolization (p = 0.02). Small asymptomatic cerebellar infarctions were demonstrated in two cases. The mean intraoperative blood loss was 2586 ml. Following Grade D or E embolization, intraoperative bleeding was largely related to unembolized epidural veins.

Conclusions. Tumor histology and MR imaging findings are predictive of hypervascularity; however, hypervascular tumors may not be detected by standard MR imaging sequences. Superselective catheterization permits Grade D or E embolization in 80% of patients. Shared blood supply with an RMA is the most important factor precluding complete embolization.
Management of atlantoaxial metastases with posterior occipitocervical stabilization
Authors: Fourney Daryl R. , York Julie E. , Cohen Zvi R. , Suki Dima , Rhines Laurence D. , Gokaslan Ziya L.
Published: May 2009

Object. The treatment of atlantoaxial spinal metastases is complicated by the region's unique biomechanical and anatomical characteristics. Patients most frequently present with pain secondary to instability; neurological deficits are rare. Recently, some authors have performed anterior approaches (transoral or extraoral) for resection of upper cervical metastases. The authors review their experience with a surgical strategy that emphasizes posterior stabilization of the spine and avoidance of poorly tolerated external orthoses such as the rigid cervical collar or halo vest.

Methods. The authors performed a retrospective review of 19 consecutively treated patients with C-1 or C-2 metastases who underwent surgery at The University of Texas M. D. Anderson Cancer Center between 1994 and 2001.

Visual analog pain scores were reduced at 1 and 3 months (p < 0.005, Wilcoxon signed-rank test); however, evaluation of pain at 6 months and 1 year was limited by the remaining number of surviving patients. Analgesic medication consumption was unchanged. There were no cases of neurological decline or sudden death secondary to residual or recurrent atlantoaxial disease during the follow-up period. One patient underwent revision of hardware at 11 months. The mean follow-up period was 8 months (range 1–32 months). Median survival determined by Kaplan—Meier analysis was 6.1 months (95% confidence interval 2.99–9.21).

Conclusions. Occipitocervical stabilization provided durable pain relief and preservation of ambulatory status over the remaining life span of patients. Because of the palliative goals of surgery, the authors have not found an indication for anterior-approach tumor resection in these patients. Successful stabilization obviates the need for an external orthosis.
Nuclear factor—κB-regulated cyclooxygenase-2 expression in surgery-associated paraspinal muscle injury in rats
Authors: Lu Kang , Liang Cheng-Loong , Chen Han-Jung , Chen Shang-Der , Hsu Huan-Chen , Chen Yun-Ching , Hsu Fu-Fei , Cho Chung-Lung
Published: May 2009

Object. Paraspinal muscle injury is a common but neglected complication of posterior spinal surgery. Evidence suggests that surgical retraction places mechanical and oxidative stress on the paraspinal muscles and that inflammation is a major postoperative pathological finding in the muscles. The roles of cyclooxygenase (COX)—2 and nuclear factor (NF)—κB in the inflammatory processes after retraction remains to be clarified.

Methods. In the control group, paraspinal muscles were dissected from the spine via a posterior incision and then laterally retracted. Paraspinal muscle specimens were harvested before as well as at designated time points during and after persistent retraction. The time course of NF-κB activation was determined by gel shift assay. Expression of COX-2 was examined using Western blot analysis and immunohistochemistry. The severity of inflammation was evaluated based on histopathology and myeloperoxidase (MPO) activity. The NF-κB activation was inhibited by the administration of pyrrolidine dithiolcarbamate (PDTC) in the PDTC-treated group. Retraction induced early activation of NF-κB in paraspinal muscle cells. The expression of COX-2 could not be detected until 1 day postoperativley, reaching a peak at 3 days. The time course of COX-2 expression correlated with that of inflammatory responses and MPO activity. Pretreatment with PDTC inhibited intraoperative NF-κB activation and greatly downregulated postoperative COX-2 expression and inflammation in the muscles. Postinflammation fibrosis was also abolished by PDTC administration.

Conclusions. Both NF-κB-regulated COX-2 expression and inflammation play an important role in the pathogenesis of surgery-associated paraspinal muscle injury. The therapeutic strategy of NF-κB inhibition may be applicable to the prevention of such injury.
The transverse process, intertransverse space, and vertebral artery in anterior approaches to the lower cervical spine
Authors: Kawashima Masatou , Tanriover Necmettin , Rhoton Albert L. , Matsushima Toshio
Published: May 2009

Object. The microsurgical anatomy of the C3–6 transverse processes and their relationship to the intertransverse space and vertebral artery (VA) were examined with special attention to the aspect exposed in the anterior surgical approach.

Methods. Ten adult cadaveric spines were examined (magnification levels × 3–40) after perfusion of the arteries and veins with colored silicone. The morphological detail of the transverse process and intertransverse space, the distances between selected surgical landmarks and the VA were measured, and the means and standard deviations were calculated. The osseous changes in the anterior root of the transverse process were classified according to their extent.

The transverse processes became smaller, and the anterior intertransverse spaces and the width of the VA exposed in the space increased in size proceeding from caudal to rostral levels, thus exposing the VA to increased risk of injury during procedures at cephalad levels. The distance between the medial border of the longus colli muscle and the VA decreased when proceeding caudally from C2–3 to C4–5 interspaces but began to increase at the level of C5–6. The VA coursed closer to the lateral border of the vertebral body than to the medial border of the anterior tubercle of the transverse process. Osseous changes consisting of thinning or defects in the anterior root of the transverse process were observed from C-3 to C-5. The thinning was most prominent in the lower half of the anterior root just above where the VA ascends behind the lower edge of the anterior root. The osseous change may reflect the erosive effect of the VA on the anterior root of the transverse process.

Conclusions. This study provides new information regarding the transverse process and especially the anterior root. An awareness of the thinness and defects in the anterior root of the transverse process and the relationships to the surrounding area will aid in reducing VA injury during anterior approaches to the cervical spine.
Primary epidural lymphoma
Authors: Alameda Francesc , Pedro Carme , Besses Carles , Galitó Emili , Mariñoso Maria Luisa , Munne Assumpta , Serrano Sergi
Published: May 2009

✓ A case of follicular center cell lymphoma arising in the spinal dura mater is presented. To the authors' knowledge, this is the first case of primary epidural lymphoma in which immunohistochemical and molecular investigations demonstrated a follicular center cell origin.
Inflammatory myofibroblastic tumor: a spinal case with aggressive clinical course and ALK overexpression
Authors: Lacoste-Collin Laetitia , Roux Franck-Emmanuel , Gomez-Brouchet Anne , Despeyroux Marie-Line , Uro-Coste Emmanuelle , Coindre Jean-Michel , Delisle Marie-Bernadette
Published: May 2009

✓ The authors report on a case of spinal inflammatory myofibroblastic tumor (IMT) in a 22-year-old woman. Neuroradiological features of this intradural extramedullary mass were suggestive of a meningioma or neurinoma. The lesion was easily resected following a T-9 laminectomy. Light microscopy showed a proliferation of spindle cells with prominent nucleoli on a fibrous or edematous background with infiltration of numerous lymphocytes and plasma cells. Some spindle cells immunostained positively for ALK1. This led to the diagnosis of IMT. The patient's postoperative course was complicated by a multifocal local recurrence requiring a second surgery, which was followed by radio- and chemotherapy. The occurrence of IMT in the spinal cord has rarely been reported. In this case, ALK overexpression was associated with early multifocal recurrence. This has been recently reported in this tumor type in other locations.
Occipitocervical reconstruction with the Ohio Medical Instruments Loop: results of a multicenter evaluation in 30 cases
Authors: Singh Sheila K. , Rickards Lynda , Apfelbaum Ronald I. , Hurlbert R. John , Maiman Dennis , Fehlings Michael G.
Published: May 2009

Object. Stabilization of the craniocervical junction (CCJ) remains a significant challenge. In this multicenter study, the authors present the results of an evaluation of a precontoured titanium implant, the Ohio Medical Instruments (OMI) Loop, for craniocervical fixation.

Methods. In this multicenter retrospective study the authors evaluated 30 patients (16 female, 14 male; mean age 53.8 years) with rheumatoid arthritis (15 cases), traumatic occipitoatlantoaxial instability (six cases), congenital vertebral anomalies (two cases), instability due to basilar invagination in the setting of Chiari malformation (two cases), or Down syndrome (one case), tumor (one case), os odontoideum (two cases), and pseudarthrosis/other (one case), who underwent OMI Loop—assisted occipitocervical reconstruction. The mean follow-up period was 25.4 months (range 6–60 months).

A solid reconstruction was achieved in 29 of 30 cases; there was only one case of hardware failure requiring reoperation. Noncritical hardware failure occurred in two patients in whom partial occipital screw backout occurred but did not necessitate reoperation. There were no perioperative neurological complications. One patient (3.3%) experienced a delayed postoperative worsening of myelopathy at 1 year that resolved with further surgery. Postoperatively, in 66.6% of patients the degree of myelopathy remained stable (as measured by American Spinal Injury Association [ASIA] scores), whereas 30% improved by one or more ASIA grade. The rate of osseous fusion was 96.6% at a mean follow-up period of 25.4 months.

Conclusions. The authors found that the OMI Loop is a versatile precontoured occipitocervical fixation device that can be applied to a wide range of CCJ lesions. It provides excellent immediate rigid fixation of the CCJ, a high rate of osseous fusion, and a low rate of hardware failure.
Evaluation of anorectal function in patients with tethered cord syndrome: saline enema test and fecoflowmetry
Authors: Kayaba Hiroyuki , Hebiguchi Tatsuzo , Itoh Yasunobu , Yoshino Hiroaki , Mizuno Masaru , Morii Mayako , Adachi Tetsuya , Chihara Junichi , Kato Tetsuo
Published: May 2009

Object. Disturbance in anorectal function is a major factor restricting the activities of daily living in patients with spinal cord disorders. To detect changes in anorectal motilities due to a tethered spinal cord, anorectal functions were evaluated using a saline enema test and fecoflowmetry before and after patients underwent untethering surgery.

Methods. The bowel functions in five patients with a tethered cord syndrome (TCS) were evaluated by performing a saline enema test and fecoflowmetry. The contractile activity of the rectum, the volume of infused saline tolerated in the rectum, anal canal pressure, and the ability to evacuate rectal content were examined.

The characteristic findings in anorectal motility studies conducted in patients with TCS were a hyperactive rectum, diminished rectal saline-retention ability, and diminished maximal flow in saline evacuation. A hyperactive rectum was considered to be a major contributing factor to fecal incontinence. In one asymptomatic patient diminished anal squeezing pressure was exhibited and was incontinent to liquid preoperatively, but recovered after surgery. Two patients who underwent surgery for myeloschisis as infants complained of progressive fecal incontinence when they became adolescents. In one patient fecal incontinence improved but in another patient no improvement was observed after untethering surgery.

Conclusions. Fecodynamic studies allow the detection of neurogenic disturbances of the anorectum in symptomatic and also in asymptomatic patients with TCS. More attention should be paid to the anorectal functions of patients with TCS.
Atlantoaxial interlaminar distances in cervical flexion in children
Authors: Tubbs R. Shane , Smyth Matthew D. , Wellons John C. , Blount Jeffrey P. , Grabb Paul A. , Oakes W. Jerry
Published: May 2009

Object. To the best of the authors' knowledge, no quantitative analysis of the atlantoaxial interlaminar distance in flexion (ILD) in children exists in the medical literature. In this study they sought to determine the age-matched relationship between the posterior elements of the atlas and axis in children in cervical spine flexion, to be used as an adjunct to the atlantodental interval in common clinical use.

Methods. Lateral radiographs of the cervical spine in full flexion were analyzed in 74 children. The atlantoaxial ILD was defined as the distance between a midpoint of the anterior cortices of the atlantal and axial posterior arches.

The mean ILD for the entire group was 19 mm (range 8–30 mm). No significant difference was seen between male and female patients (p = 0.084). When stratified by age, the mean ILD was 12.3 ± 3 mm (15 cases) in children age 3 years or younger and 20.5 ± 4.7 mm (59 cases) in children age older than 3 years. Further stratification of the groups yielded a mean ILD of 10.4 ± 1.4 [eight cases]) in children age 1 to 2 years, and 14.4 ± 4.7 mm (seven cases) in children age 3 years. In children older than 3 years of age the mean ILD was consistently approximately 20 ± 5 mm regardless of age.

Conclusions. Rapid, safe, and accurate diagnosis of the cervical spine is essential in critical care. Knowledge of the distance between the posterior elements of the atlas and axis in flexion should enhance the clinicians' (those who clear cervical spines) ability to diagnose accurately atlantoaxial instability on lateral radiographs obtained in flexion.
A new endoscopic technique to decompress lumbar nerve roots affected by spondylolysis
Authors: Sairyo Koichi , Katoh Shinsuke , Sakamaki Tadanori , Komatsubara Shinji , Yasui Natsuo
Published: May 2009

✓ The authors describe a new endoscopic technique to decompress lumbar nerve roots affected by spondylolysis. Short-term clinical outcome was evaluated. Surgery-related indications were: 1) radiculopathy without low-back pain; 2) no spinal instability demonstrated on dynamic radiographs; and 3) age older than 40 years. Seven patients, four men and three women, fulfilled these criteria and underwent endoscopic decompressive surgery. Their mean age was 60.9 years (range 42–70 years). No subluxation was present in four patients, whereas Meyerding Grade I slippage was demonstrated in three. For endoscopic decompression, a skin incision of 16 to 18 mm in length was made, and fenestration was performed to identify the affected nerve root. The proximal stump of the ragged edge of the spondylotic lesion, and the fibrocartilaginous mass compressing the nerve root were removed. The follow-up period ranged from 6 to 22 months (mean 11.7 months). Clinical outcome was evaluated using Gill criteria; in three patients the outcome was excellent, and in four it was good. This new endoscopic technique was useful in the decompression of nerve roots affected by spondylolysis, the technique was minimally invasive, and the clinical results were acceptable.
A new table-fixed retractor for anterior odontoid screw fixation
Authors: Hott Jonathan S. , Henn Jeffrey S. , Sonntag Volker K. H.
Published: May 2009

✓ The authors describe a unique retraction device adapted for anterior odontoid screw placement. A rigidly fixed tubular retractor system obviates the need for dissecting the longus colli muscles as well as for excessive retraction of the trachea, esophagus, and recurrent laryngeal nerve. The proper trajectory for screw placement can be determined by fine manipulation of the retractor as determined by biplanar fluoroscopy. The retractor is then rigidly fixed in position. The tubular corridor permits the odontoid screw to be placed in the usual fashion.
Titanium cage reconstruction after cervical corpectomy
Authors: Dorai Zeena , Morgan Howard , Coimbra Caetano
Published: May 2009

Object

The authors evaluated the efficacy of titanium cage— and anterior cervical plate (ACP)—augmented fusion for reconstruction following decompressive cervical corpectomy in nontraumatic disease.

Methods

Forty-five patients ranging from 37 to 77 years of age underwent anterior cervical corpectomy followed by titanium cage—assisted reconstruction in which the cages were filled with autologous bone obtained from the resected vertebral bodies (VBs). Plates were placed in all patients. Follow-up radiographic evaluation included computerized tomography scanning and plain flexion—extension radiography.

Fusion was demonstrated in all but one patient without reconstruction-related complications. The single complication involved an endplate VB fracture with pistoning of the cage into the VB. The mean follow-up period was 12.9 months.

Conclusions

Autologous corpectomy bone—filled titanium cages supplemented with ACPs are an effective means of reconstruction after compressive cervical corpectomy. This technique provides a reasonable alternative to procedures involving long solid strut grafts obtained from the bone bank or from the patient.
Diagnostic accuracy of magnetic resonance imaging for detecting posterior ligamentous complex injury associated with thoracic and lumbar fractures
Authors: Haba Hitoshi , Taneichi Hiroshi , Kotani Yoshihisa , Terae Satoshi , Abe Satoru , Yoshikawa Hiroyuki , Abumi Kuniyoshi , Minami Akio , Kaneda Kiyoshi
Published: May 2009

Object

The posterior ligamentous complex (PLC) in the thoracic and lumbar spine is one of the region's important stabilizers. The precise diagnosis of PLC injury is required to evaluate the instability of the injured spine; however, the accuracy of magnetic resonance (MR) imaging for diagnosing PLC injury has remained unclear. In this study, the authors compared preoperative MR imaging findings with direct intraoperative observation of PLC injury, clarifying the former's diagnostic accuracy regarding detection of PLC injury associated with the thoracic and lumbar fractures.

Methods

Data obtained in 35 patients who sustained thoracic or lumbar injuries were reviewed. There were 17 burst fractures, six flexion—distraction injuries, and 12 fracture dislocations. Each patient underwent MR imaging examination within 3 weeks of injury. Three radiologists independently evaluated sagittal MR images in a blinded fashion. The PLC-related information was retrospectively collected from each operative record. The diagnostic accuracy of MR imaging was analyzed by comparing imaging-documented intraoperative findings.

The PLC injuries were detected in 23 patients (65.7%) by direct observation during posterior spinal procedures. The diagnostic accuracy of MR imaging in detecting injury of the supraspinous ligament (SSL) and interspinous ligament (ISL) was 90.5 and 94.3%, respectively. The specificity of T1-weighted MR imaging alone for depicting the SSL was significantly greater than T2-weighted imaging alone (p < 0.05). The overall mean κ coefficient for MR imaging findings of PLC injury was 0.803, which indicated excellent interobserver reliability; that for ISL (0.915) was significantly greater than that for SSL (0.69) (p < 0.05).

Conclusions

This study clarified a high diagnostic accuracy and interobserver reliability of MR imaging for PLC injury. The precise diagnosis of PLC injury is essential to determine the mechanical instability of the injured thoracic and lumbar spine, especially in differentiating unstable (three-column) burst fractures from the relatively stable (two-column) type. The authors conclude that MR imaging is a powerful diagnostic tool to evaluate PLC injury associated with thoracic and lumbar fractures.
Immunohistochemical analysis of the extracellular matrix in the posterior capsule of the zygapophysial joints in patients with degenerative L4–5 motion segment instability
Authors: Boszczyk Bronek M. , Boszczyk Alexandra A. , Korge Andreas , Grillhösl Andreas , Boos Wolf-Dietrich , Putz Reinhard , Milz Stefan , Benjamin Michael
Published: May 2009

Object

Although the hypertrophied shape of the zygapophysial joints in degenerative instability of the lumbar spine is well known, its underlying pathophysiological mechanism is unclear. The authors sought to provide evidence that there is increased fibrocartilaginous metaplasia in the posterior joint capsule resulting from greater mechanical loading; the authors suggest that these capsular changes are central to understanding the altered joint shape.

Methods

The L4–5 posterior articular complex was removed in 14 patients undergoing fusion for degenerative instability. After methanol-assisted fixation, cryosections were immunolabeled for a wide range of extracellular matrix molecules. These were collagens (Types I, II, III, V, and VI), glycosaminoglycans (chondroitin 4 and 6 sulfates; dermatan- and keratan-sulfate), and proteoglycans (versican, tenascin, aggrecan, and its associated link protein). The grade of degeneration of the articular complexes was assessed radiologically and histologically.

Conclusions

The results of this study provide molecular evidence for an altered loading history on the joint capsule. The pronounced loss of intervertebral disc height that occurred in all patients with severe degeneration of the lumbar motion segment promotes an increased range of axial rotation that places the posterior capsule under greater mechanical load. Compared with normal joints studied previously, the posterior capsules involved in these degenerative joint complexes were hypertrophied and fibrocartilaginous throughout. Cartilaginous metaplasia was especially pronounced at the attachment sites (entheses) where the fibrocartilage now extended beyond the original level of the joint space, and capped the osseous spurs arising from these attachment sites.
Thoracoscopic limited T-3 sympathicotomy for primary hyperhidrosis: prevention for compensatory hyperhidrosis
Authors: Yoon Do Heum , Ha Yoon , Park Yong Gou , Chang Jin Woo
Published: May 2009

Object

Compensatory hyperhidrosis is a major and troublesome complication of thoracoscopic sympathectomy for primary hyperhidrosis. The incidence of compensatory hyperhidrosis has been reported to be as high as 50 to 97% in the patients who underwent sympathetic ganglia resection. In this study the authors evaluate the role of thoracoscopic T-3 sympathicotomy for primary hyperhidrosis and the prevention of compensatory hyperhidrosis.

Methods

Thoracoscopic T-3 sympathicotomy was performed in 27 patients with either isolated palmar hyperhidrosis (24 cases) or that in combination with axillary hyperhidrosis (three cases) during a 3-year period. In the cases of combined palmar/axillary hyperhidrosis, the T-4 sympathetic ganglion also was coagulated. The mean follow-up period was 19.7 months. Surgery-related results were determined on the basis of complications, compensatory hyperhidrosis, and patient-related satisfaction.

In the immediate postoperative period all 24 patients with palmar hyperhidrosis reported complete alleviation of their symptoms. One patient with palmar/axillary hyperhidrosis in whom axillary hyperhidrosis did not completely resolve underwent a repeated T-4 sympathicotomy 1 month after the initial surgery. Another patient suffered mild compensatory hyperhidrosis of the trunk 1 month postoperatively. The long-term satisfaction rate in all 27 patients was high. One patient required placement of a chest tube to treat pneumothorax. Other complications such as Horner syndrome, intercostal neuralgia, gustatory hyperhidrosis, and pulmonary edema were not observed.

Conclusions

Thoracoscopic limited T-3 sympathicotomy is an effective method to treat primary hyperhidrosis, its rate of compensatory hyperhidrosis is low, and its rate of long-term patient satisfaction is high.
Kyphoplasty for vertebral compression fractures: 1-year clinical outcomes from a prospective study
Authors: Coumans Jean-Valéry C. E. , Reinhardt Mary-Kay , Lieberman Isador H.
Published: May 2009

Object

Over the past 15 years, vertebroplasty has emerged as a treatment for vertebral compression fractures. This technique, however, does not restore vertebral height and is associated with a high rate of cement leakage. Recently, kyphoplasty was developed in an effort to circumvent this problem. Although its immediate results have been reported, it is unclear whether the benefits endure.

Methods

Seventy-eight consecutive patients underwent 188 kyphoplasty procedures. The patients responded to Short Form—36 (SF-36) questionnaires, a visual analog scale (VAS) for pain rating, and the Oswestry disability index (ODI) instrument; additionally they underwent detailed neurological and radiographic examinations pre- and postoperatively. The preoperative SF-36, VAS, and ODI scores, the neurological examination results, and the radiographic data were compared with the postoperative findings.

Thirteen patients died of disease progression or unrelated illness. Of the surviving patients, complete data were available in 62% (minimum follow-up period 12 months, mean 18 months). Complications included one myocardial infarction and five cases of asymptomatic cement extravasation. No case of neurological deterioration occurred during the follow-up period. Significant improvements in seven measures of the SF-36 inventory as well as on the ODI and VAS were noted early postoperatively, and these persisted throughout the follow-up period, despite a statistically insignificant decline in the measure of general health at last follow-up examination.

Conclusions

Kyphoplasty is an effective treatment for vertebral compression fractures. The benefits presented in the early postoperative period and persisted at 1 year posttreatment.
Volumetric quantification of cement leakage following percutaneous vertebroplasty in metastatic and osteoporotic vertebrae
Authors: Mousavi Payam , Roth Sandra , Finkelstein Joel , Cheung Gordon , Whyne Cari
Published: May 2009

Object

The goal of this study was to quantify volumetrically cement fill and leakage in patients with osteoporotic and metastatic vertebral lesions undergoing percutaneous vertebroplasty and to establish whether these factors have any clinical significance at follow up.

Methods

Digital computerized tomography data were retrospectively collected from all cases at the authors' institution in which percutaneous vertebroplasty was performed for osteoporosis or metastatic disease. Patient selection was based on the consensus of a multidisciplinary team consisting of an orthopedic surgeon, an oncologist, and a neuroradiologist. A semiautomated thresholding technique was used to measure vertebral body volume, the volume of cement injected directly into the vertebra, and the volume of cement leakage. Pain-related scores were collected at four early stages of treatment, and all clinical complications were recorded.

Cement leakage was found in 87.9% of vertebrae treated with percutaneous vertebroplasty. In osteoporotic vertebrae it occurred mainly in the disc, whereas in metastatic lesions, it was found in multiple areas. Irrespective of leakage, both patients with osteoporotic and metastatic disease experienced significant immediate pain relief postoperatively.

Conclusions

Although there was no correlation between cement fill or cement leakage and pain relief, there exists a risk of serious complications due to cement leakage.
Sonic hedgehog—induced neural precursor proliferation after adult rodent spinal cord injury
Authors: Bambakidis Nicholas C. , Wang Rui-Zhen , Franic Linda , Miller Robert H.
Published: May 2009

Object

The glycoprotein molecule sonic hedgehog (Shh) has been shown to play a critical role in neuraxial development. To assess its role in the repair of demyelination following spinal cord injury (SCI), escalating doses of Shh were injected into demyelinated lesions in adult rat spinal cords.

Methods

Twenty-seven adult rats underwent thoracic laminectomy and chemical demyelination of the spinal cord dorsal columns without neurological deficit. A subset of 20 rats was treated after 3 days by direct injection of Shh at two different doses. Rats were killed at 7 or 21 days after SCI, and tissue samples underwent immediate fixation or were placed into cell culture. Diffuse cellular proliferative responses throughout the gray and white matter were observed in up to 70% of Shh-treated rats. Proliferation around the central canal, believed to be derived from the ventricular ependyma consistent with neuronal stem cell induction, was demonstrated in up to 60% of the treated rats. No significant proliferation in these areas was detected in control rats. Dorsal areas of nestin-positive cells were also observed in 70% of rats treated with high doses of Shh, and these observations were reproduced in cell culture as well as in cultures of dorsal spinal cord explants. Cell counts revealed significant increases in the percentage of oligodendrocyte precursors and neurons in treated compared with control rats.

Conclusions

Exogenous Shh administration promotes nestin-positive cell proliferation after SCI in adult rodents. These cells are believed to be derived from neural precursor cells. The populations of oligodendrocyte precursors and neurons were likewise increased in Shh-treated rats, suggesting that these cells may be derived from neural stem cells.
In vitro biomechanical comparison of pedicle screws, sublaminar hooks, and sublaminar cables
Authors: Hitchon Patrick W. , Brenton Matthew D. , Black Andrew G. , From Aaron , Harrod Jeremy S. , Barry Christopher , Serhan Hassan , Torner James C.
Published: May 2009

Object

Three types of posterior thoracolumbar implants are in use today: pedicle screws, sublaminar titanium cables, and sublaminar hooks. The authors conducted a biomechanical comparison of these three implants in human cadaveric spines.

Methods

Spine specimens (T5–12) were harvested, radiographically assessed for fractures or metastases, and their bone mineral density (BMD) was measured. Individual vertebrae were disarticulated and fitted with either pedicle screws, sublaminar cables, or bilateral claw hooks. The longitudinal component of each construct consisted of bilateral 10-cm rods connected with two cross-connectors. The vertebral body was embedded in cement, and the rods were affixed to a ball-and-socket apparatus for the application of a distraction force.

The authors analyzed 1) 20 vertebrae implanted with screws; 2) 20 with hooks, and 3) 20 with cables. The maximum pullout (MPO) forces prior to failure (mean ± standard deviation) for the screw, hook, and cable implants were 972 ± 330, 802 ± 356, and 654 ± 248 N, respectively (p = 0.0375). Cables allowed significantly greater displacement (6.80 ± 3.95 mm) prior to reaching the MPO force than hooks (3.73 ± 1.42 mm) and screws (4.42 ± 2.15 mm [p = 0.0108]). Eleven screw-implanted vertebrae failed because of screw pullout. All hook-and-cable—implanted vertebrae failed because of pedicle, middle column, or laminar fracture.

Conclusions

These findings suggest that screws possess the greatest pullout strength of the three fixation systems. Sublaminar cables are the least rigid of the three. When screw failure occurred, the mechanism was generally screw backout, without vertebral fractures.
Magnetic resonance imaging of intramedullary spinal cord schwannomas
Authors: Colosimo Cesare , Cerase Alfonso , Denaro Luca , Maira Giulio , Greco Romano
Published: May 2009

✓ Intramedullary spinal cord schwannomas are rare benign tumors for which resection is possible and safe. The purpose of this paper is to present the magnetic resonance (MR) imaging features in two cases of intramedullary spinal cord schwannoma to assist both neurosurgeons and pathologists in preventing misdiagnosis and resultant partial resection. The MR imaging evidence of a small- or medium-sized well-marginated intramedullary spinal cord tumor in a patient in whom no syringomyelia is present but in whom moderate edema with marked Gd enhancement can be seen should be considered in the differential diagnosis of intramedullary spinal cord schwannoma. In cases in which an associated thickened Gd-enhancing spinal nerve root is seen the diagnosis of schwannoma should be assumed.
A new table-fixed retractor for anterior odontoid screw fixation: technical note
Authors: Hott Jonathan S. , Henn Jeffrey S. , Sonntag Volker K. H.
Published: May 2009

✓ The authors describe a unique retraction device adapted for anterior odontoid screw placement. A rigidly fixed tubular retractor system obviates the need for dissecting the longus colli muscles as well as for excessive retraction of the trachea, esophagus, and recurrent laryngeal nerve. The proper trajectory for screw placement can be determined by fine manipulation of the retractor as determined by biplanar fluoroscopy. The retractor is then rigidly fixed in position. The tubular corridor permits the odontoid screw to be placed in the usual fashion.
Clinicopathological study of “snake-eye appearance” in compressive myelopathy of the cervical spinal cord
Authors: Mizuno Junichi , Nakagawa Hiroshi , Inoue Tatsushi , Hashizume Yoshio
Published: May 2009

Object. The goal of this study was to elucidate the pathophysiological features and clinical significance of the magnetic resonance imaging—documented small intramedullary high signal intensity known as “snake-eye appearance” (SEA) in cases of compressive myelopathy such as cervical spondylosis or ossification of the posterior longitudinal ligament.

Methods. One hundred forty-four patients with compression myelopathy who underwent surgery between 1998 and 2000 were selected. Intramedullary high signal intensity was found in 79 cases and was divided into two types, SEA and non-SEA (NSEA). The Japan Orthopaedic Association (JOA) scoring system was used for evaluation of pre- and postoperative neurological status. In nine cases of SEA autopsy was performed and specimens were histologically analyzed.

The improvement ratio determined by JOA score was 32.2 ± 15.1% in SEA, 47.1 ± 12.1% in NSEA, and 50 ± 18.3% (p < 0.01) in control cases in which high signal intesity was absent. There were significant differences among SEA, NSEA, and control groups. In a separate group of nine patients who died of unrelated causes, histological examination showed small cystic necrosis in the center of the central gray matter of the ventrolateral posterior column and significant neuronal loss in the flattened anterior horn.

Conclusions. Snake-eye appearance was found to be a product of cystic necrosis resulting from mechanical compression and venous infarction. Destruction of the gray matter accompanying significant neuronal loss in the anterior horn suggested that SEA is an unfavorable prognostic factor for the recovery of upper-extremity motor weakness.
Atypical presentation of C-7 radiculopathy
Authors: Ozgur Burak M. , Marshall Lawrence F.
Published: May 2009

Object. The authors retrospectively reviewed the presenting symptomatology and 6-month outcome in 241 consecutive patients who underwent C6–7 anterior cervical discectomy (ACD) from an overall series of 1008 patients in whom the senior author performed one-level procedures.

Methods. In 28 (12%) of the 241 patients, the sole complaint was subscapular pain on the side ipsilateral to nerve root compression. In 11 patients (5%), the primary complaint was unilateral deep breast or chest pain. No patient experienced any of the traditional radicular signs involving C-7 such as numbness of the second or third digits, pain in the triceps, and/or atrophy or weakness of the triceps or pronator muscles. Of the 28 patients presenting with subscapular pain 238 (93%) of 241 experienced complete symptom relief within 6 months, and of the 11 who presented with chest pain complete relief or relief to the point of requiring nonnarcotic analgesic agents occurred in nine cases.

Conclusions. Approximately 15% of patients with a C-7 radiculopathy are likely to present with atypical symptoms that, if persisting after nonsurgical therapy, will often resolve after ACD and fusion.