bluuebunny/crossref_metadata_2025 huggingface dataset:
Posterior lumbar interbody fusion with bioabsorbable spacers and local autograft in a series of 27 patients
Authors: Couture Daniel E. , Branch Charles L.
Published: January 2008

Object

The goal of this prospective study was to review a series of 27 patients who underwent bilateral posterior lumbar interbody fusion with instrumented pedicle fixation and two HYDROSORB (known generically as 70:30 poly[L-lactide-co-D,L-lactide]) rectangular cages packed with locally harvested autograft at a total of 48 levels, and to assess the safety and efficacy of this novel technique. This analysis, conducted at a mean of 26 months of follow up, is the first report of a long-term evaluation of this technique. Fusion rates and clinical outcomes are presented.

Methods

A prospective clinical and radiographic review of findings in 27 consecutive patients was performed. Fusion rates and clinical outcome were assessed at 6-month intervals up to the 32-month follow-up end point. Two patients with four corresponding fusion levels were lost to follow up.

Radiographic evidence of satisfactory fusion was achieved in 42 (95.5%) of 44 levels fused. Satisfactory fusion at all levels was achieved in 23 (92%) of 25 patients. Two patients required repeated operations for treatment of symptomatic pseudarthrosis during the study period. The likelihood of all levels attaining fusion in a given patient decreased as the number of levels treated increased, which is consistent with previously published studies. Nonetheless, fusion rates per treated level were similar for patients in whom one to three levels were treated. No significant surgical complication occurred.

Conclusions

Posterior lumbar interbody fusion in which the HYDROSORB bioabsorbable implant packed with locally harvested autograft and segmental internal fixation are used appears to be an interbody fusion alternative whose efficacy is comparable with previously reported procedures.
Syndrome of inappropriate secretion of antidiuretic hormone and hyponatremia after spinal surgery
Authors: Amini Amin , Schmidt Meic H.
Published: January 2008

Hyponatremia caused by an inappropriately high level of antidiuretic hormone secretion after spinal surgery is an uncommon and self-limiting phenomenon that resolves within 2 or 3 weeks. During the early postoperative period, the patient's urine output and serum level of sodium should be monitored closely to prevent possible serious complications of the syndrome of inappropriate secretion of antidiuretic hormone. Symptoms vary depending on the severity of the hyponatremia and can range from mild headache, muscle cramps, nausea, and vomiting to convulsions, coma, and death. Treatment options include fluid restriction, oral intake of salt, and hypertonic saline. It is important that spine surgeons recognize this phenomenon early and treat it appropriately and conservatively to prevent possible serious complications.
Growth hormone replacement for patients with adult onset growth hormone deficiency—what have we learned?
Authors: Piersanti Monique
Published: January 2008

Growth hormone (GH) deficiency is a condition recognized to occur in individuals who have had multiple pituitary hormone deficiencies as a result of pathological processes or neurosurgical interventions. The indications, benefits, and risks of GH replacement therapy will be reviewed with an emphasis on those patients who were adults with the deficiency first emerged. The results of this analysis indicate that, although a measurable improvement can be detected in the patient's quality of life, body composition, and some cardiovascular parameters, the larger questions of long-term benefit and patient selection currently remain unanswered.
Treatment of patients with a pituitary adenoma: one clinican's experience
Authors: Vance Mary Lee
Published: January 2008

The diagnosis and treatment of a patient with a pituitary adenoma or another type of pituitary lesion requires a team approach involving the neurosurgeon, endocrinologist, primary care physician, and, in some patients, an ophthalmologist and radiation therapist. The diagnosis of excessive pituitary hormone secretion and/or loss of pituitary function is based on biochemical findings and can usually be confirmed by performing blood tests, except for patients with suspected Cushing syndrome. The primary treatment of pituitary adenomas is resection, except in patients with a prolactin-producing tumor, who are most successfully treated medically with a dopamine agonist. In this article the author reviews the principles of diagnosis and treatments and offers recommendations for ideal patient care.
Pharmacological approach to the treatment of acromegaly
Authors: Ezzat Shereen
Published: January 2008

The treatment of patients with persistently active acromegaly has been facilitated over the past decade by the advent of highly specific and selective pharmacological agents. Somatostatin analogs, derived from the native inhibitory hormone somatostatin, are available in extended-duration preparations and are effective in reducing serum levels of growth hormone (GH) and insulin-like growth factor–I (IGF-I) as well as in improving the adverse clinical effects of acromegaly. Cabergoline, an agonist with a specificity for the dopamine D-2 receptor, has been shown to suppress IGF-I levels and induce tumor shrinkage in 35 and 50% of patients, respectively. The GH receptor antagonists compete with naturally occurring GH for binding with the GH receptor. As such, pegvisomant normalizes circulating IGF-I levels in 80 to 90% of patients with acromegaly. This last line of therapy should be considered for use in patients in whom surgery and medical therapy with somatostatin and/or dopamine agonists are either ineffective or poorly tolerated.
Stereotactic radiosurgery for Cushing disease
Authors: Hentschel Stephen J. , McCutcheon Ian E.
Published: January 2008

The most common cause of Cushing syndrome is Cushing disease, in which hypercortisolism is produced by a functional adrenocorticotropic hormone–producing adenoma of the anterior pituitary gland. The common therapies available include microsurgical resection, conventional fractionated radiotherapy, and stereotactic radiosurgery (SRS). In this article the authors review the indications, results, and complications associated with SRS in the treatment of Cushing disease.

In as many as 90% of patients SRS results in disease remission, which is defined as a normal 24-hour urinary free cortisol level and a normal or subnormal morning serum cortisol level. Although in most patients who are subsequently cured a marked decrease in the serum cortisol level is demonstrated within 3 months after treatment, a biochemical cure may be delayed up to 3 years in some cases. Complications following SRS for pituitary adenomas are uncommon, particularly in patients with microadenomas, which are most commonly seen in Cushing disease. The most common complication is hypopituitarism, which occurs in up to 50% of patients with a mean latency period of 5 years. Radiation-induced optic neuropathy has been reported in less than 2% of cases and induction of a secondary neoplasm in less than 1% of cases.

For patients with Cushing disease, the rate of endocrinological cure following SRS appears to be similar to that attained using microsurgical resection. In contrast to surgery, SRS has the benefit of being noninvasive and associated with a very low incidence of diabetes insipidus, although hypopituitarism may be more common with SRS. With continued follow-up patient reviews and additional experience with SRS, it may become possible to make more definitive statements regarding SRS as the initial treatment for patients with Cushing disease.
Pituitary carcinoma: a review of the literature
Authors: Ragel Brian T. , Couldwell William T.
Published: January 2008

Pituitary carcinomas, defined as distant metastases of a pituitary neoplasm, are rare; fewer than 140 reports exist in the English literature. The initial presenting pituitary tumor is usually a secreting, invasive macroadenoma, with adrenocorticotropic hormone (ACTH)– and prolactin (PRL)–secreting tumors being the most common. The latency period between the diagnosis of a pituitary tumor and the diagnosis of a pituitary carcinoma is 9.5 years for ACTH-producing lesions and 4.7 years for PRL-secreting tumors. Survival after documentation of metastatic disease is poor; 66% of patients die within 1 year. Treatment options include additional surgery, radiotherapy, and chemotherapy, all of which are associated with poor results. Future studies will focus on identifying those invasive pituitary tumors most likely to metastasize and treating them aggressively before they progress to pituitary carcinomas.
Metastases to the pituitary gland
Authors: Fassett Daniel R. , Couldwell William T.
Published: January 2008

Only 1% of all pituitary surgeries are performed to treat tumors that have metastasized to the pituitary gland; however, in certain cases of malignant neoplasms pituitary metastases do occur. Breast and lung cancers are the most common diseases that metastasize to the pituitary. Breast cancer metastasizes to the pituitary especially frequently, with reported rates ranging between 6 and 8% of cases.

Most pituitary metastases are asymptomatic, with only 7% reported to be symptomatic. Diabetes insipidus, anterior pituitary dysfunction, visual field defects, headache/pain, and ophthalmoplegia are the most commonly reported symptoms. Diabetes insipidus is especially common in this population, occurring in between 29 and 71% of patients who experience symptoms.

Differentiation of pituitary metastasis from other pituitary tumors based on neuroimaging alone can be difficult, although certain features, such as thickening of the pituitary stalk, invasion of the cavernous sinus, and sclerosis of the surrounding sella turcica, can indicate metastasis to the pituitary gland. Overall, neurohypophysial involvement seems to be most prevalent, but breast metastases appear to have an affinity for the adenohypophysis. Differentiating metastasis to the pituitary gland from bone metastasis to the skull base, which invades the sella turcica, can also be difficult. In metastasis to the pituitary gland, surrounding sclerosis in the sella turcica is usually minimal compared with metastasis to the skull base.

Treatment for these tumors is often multimodal and includes surgery, radiation therapy, and chemotherapy. Tumor invasiveness can make resection difficult. Although surgical series have not shown any significant survival benefits given by tumor resection, the patient's quality of life may be improved. Survival among these patients is poor with mean survival rates reported to range between 6 and 22 months.
Primary brachial plexus tumors: imaging, surgical, and pathological findings in 25 patients
Authors: Binder Devin K. , Smith Justin S. , Barbaro Nicholas M.
Published: January 2008

Object

The authors report on the treatment of primary brachial plexus tumors in 25 patients at the University of California, San Francisco. They compare their findings with those obtained in similar series.

Methods

The authors reviewed the electronic and medical records, radiological images, operative reports, and pathological findings in 25 consecutive cases of primary brachial plexus tumors. Cases of metastatic lesions or adjacent neoplasms extending into and involving the brachial plexus were excluded.

At presentation patients ranged in age from 19 to 71 years (mean 47 ±15 years), and neurofibromatosis was present in eight patients (32%). Presenting signs and symptoms included palpable mass (60%), numbness/paresthesias (44%), radiating pain (44%), local pain (16%), and weakness (12%). Duration of symptoms ranged from 2 months to 10 years. Neuroimaging revealed lesions ranging widely in size (volume ~1 to >100 ml). Pathological diagnoses included schwannoma (15 [60%]), neurofibroma (five [20%]), malignant peripheral nerve sheath tumor (four [16%]), and desmoid tumor (one [4%]).

Conclusions

Primary tumors arising in the brachial plexus are rare. Careful workup, surgical technique, and attention to pathological diagnosis optimize management.
Neurogenic motor evoked potentials: role in brachial plexus surgery
Authors: Burkholder Lee M. , Houlden David A. , Midha Rajiv , Weiss Erin , Vennettilli Marco
Published: January 2008

✓ Peripheral nerve graft repair after severe brachial plexus injury is futile if there is degeneration of motor fibers in the proximal nerve stump to which the graft must be attached. Traditional intraoperative neurophysiological assessment methods like nerve action potential (NAP) and somatosensory evoked potential (SSEP) monitoring have been used to evaluate proximal nerve stump integrity, but these methods do not allow evaluation of the integrity of motor fibers back to the anterior horn cell. Consequently, the authors used transcranial electrical stimulation and recorded neurogenic motor evoked potentials (MEPs) directly from the brachial plexus in a patient undergoing surgical repair of a complete upper brachial plexus injury (Erb palsy) to assess the functional continuity of motor fibers. In addition, selected elements of the brachial plexus were directly stimulated, and NAPs were recorded. Finally, SSEPs were recorded from the scalp after stimulation of selected elements of the brachial plexus. Neurogenic MEPs were present from the medial cord of the brachial plexus, but not the middle or upper trunk; NAPs were present from the lateral and posterior cords after middle trunk stimulation, but absent after upper trunk stimulation; and SSEPs were present after medial cord stimulation but absent after stimulation of the upper and middle trunks. For the first time, neurogenic MEPs were coupled with NAPs and SSEPs to evaluate successfully the functional status of motor fibers back to the anterior horn cell for accurate localization of the lesion sites.
Infraclavicular brachial plexus stretch injury
Authors: Kim Daniel H. , Murovic Judith A. , Tiel Robert L. , Kline David G.
Published: January 2008

Object

The authors report the surgery-related results obtained in 143 patients with stretch-induced infraclavicular brachial plexus injuries (BPIs). The entire series comprised 1019 operative BPIs managed at the Louisiana State University Health Sciences Center between 1968 and 1998.

Methods

Infraclavicular lesions represented 143 (28%) of the total of 509 stretch injuries involving both the infra-and supraclavicular brachial plexus, of which 366 (72%) were supraclavicular lesions. The operative approach is thoroughly outlined, and common patterns and combinations of involvement of nerves peculiar to the infraclavicular area are presented. Overall, the results of suture and graft repair were favorable for the lateral and posterior cord and their outflows. Repair of medial cord–median nerve also yielded acceptable results. The results of medial cord and medial cord–ulnar nerve, however, were poor. The incidence of associated injuries in the infraclavicular as opposed to the supraclavicular area, including shoulder dislocation and fracture and humeral fractures as well as vascular injuries including axillary artery injury was higher. Results of a literature search supported the finding that vascular injuries were increased due to the juxtaposition of vessels among the brachial plexus elements.

Conclusions

Thus, although less common than their supraclavicular counterpart, infraclavicular stretch injury lesions when they occur are technically more difficult to treat and are associated with a higher incidence of vascular and dislocation/fraction injuries. Favorable results were obtained for lateral and posterior cord lesions and their outflows, with acceptable outcome after medial cord–median nerve stretch injury repair. The results of medial cord and medial cord to ulnar nerve, however, were poor.
Gracilis free muscle transfer for restoration of function after complete brachial plexus avulsion
Authors: Barrie Kimberly A. , Steinmann Scott P. , Shin Alexander Y. , Spinner Robert J. , Bishop Allen T.
Published: January 2008

Object

The authors report the functional outcomes after functioning free muscle transfer (FFMT) for restoration of the upper-extremity movement after brachial plexus injury (BPI).

Methods

The authors conducted a retrospective review of 36 gracilis FFMT procedures performed in 27 patients with BPI between 1990 and 2000. Eighteen patients underwent a single gracilis FFMT procedure for restoration of either elbow flexion (17 cases) or finger flexion (one case). Nine patients underwent a double free muscle transfer for simultaneous restoration of elbow flexion and wrist extension (first muscle) and finger flexion (second muscle), combined with direct triceps neurotization. The results obtained in 29 cases of FFMT in which the follow-up period was 1 year are reported.

Neurotization of the donor muscle was performed using the musculocutaneous nerve (one case), spinal accessory nerve (12 cases), or multiple intercostal motor nerves (16 cases). Two second-stage muscle flaps failed secondary to vascular insufficiency. Mean electromyography-measured reinnervation time was 5 months. At a minimum follow-up period of 1 year, five muscles achieved less than or equal to Grade M2, eight Grade M3, four Grade M4, and 12 Grade M5. Transfer for combined elbow flexion and wrist extension compared with elbow flexion alone lowered the overall results for elbow flexion strength. Seventy-nine percent of the FFMTs for elbow flexion alone (single transfer) and 63% of similarly innervated muscles transferred for combined motion achieved at least Grade M4 elbow flexion strength.

Conclusions

Functioning free muscle transfer is a viable reconstructive option for restoration of upper-extremity function in the setting of severe BPI. It is possible to achieve good to excellent outcomes in terms of muscle grades with the simultaneous reconstruction of two functions by one FFMT, making restoration of basic hand function possible. More reliable results are obtained when a single FFMT is performed for a single function.
Infectious origins of cauda equina syndrome
Authors: Cohen David B.
Published: January 2008

Infections in the spine can lead to a wide range of problems for both the patient and physician. There is perhaps no more devastating complication than the neurological consequences of a cauda equina syndrome due to spinal infection. A variety of organisms and origins can make diagnosis and treatment of spinal infection a difficult task. Both pyogenic and nonpyogenic organisms can cause vertebral involvement and can result in an epidural abscess with neurological compromise. Nonetheless, these two types of infections vary greatly in terms of associated patient demographics, clinical course, and treatments. The purpose of this paper was to review these types of infections and summarize treatment recommendations for this difficult condition.
Cauda equina syndrome after induction of spinal anesthesia
Authors: Özgen Serdar , Baykan Nigar , Dogan I. Varlik , Konya Deniz , Pamir M. Necmettin
Published: January 2008

In this report the authors present a case of cauda equina syndrome that developed following induction of spinal anesthesia in a patient who had no apparent preexisting bleeding abnormality. An acute subdural hematoma caused the syndrome and was believed to have resulted from direct vascular trauma during administration of spinal anesthesia or from vascular trauma combined with thrombocytopenia in the postoperative period.
Iatrogenic spondylodiscitis
Authors: Taºdemirođlu Erol , Sengöz Ahmet , Bagatur Erdem
Published: January 2008

Iatrogenic intervertebral disc space infection is encountered following microsurgical discectomy, percutaneous laser disc decompression, automated percutaneous lumbar nucleotomy operations, and discography. The purpose of this paper is to present a case report and review the literature on the uncommon origins of pyogenic spondylodiscitis and to emphasize the significance of prophylactic antibiotic therapy following transrectal ultrasonography-guided needle biopsy of the prostate (TUGNBP). According to the authors, this is the first reported case of pyogenic spondylodiscitis as a complication of TUGNBP in the English language literature.
Deep brain stimulation of the nucleus ventralis intermedius for Holmes (rubral) tremor and associated dystonia caused by upper brainstem lesions
Authors: Nikkhah Guido , Prokop Thomas , Hellwig Bernhard , Lücking Carl Hermann , Ostertag Christoph B.
Published: January 2008

✓Holmes tremor is caused by structural lesions in the perirubral area of the midbrain. Patients often present with associated symptoms such as dystonia and paresis, which are usually refractory to medical therapy. Here, the authors describe two patients in whom both tremor and associated dystonia improved markedly following unilateral stimulation of the thalamic nucleus ventralis intermedius.
Deep brain stimulation in the treatment of dyskinesia and dystonia
Authors: Toda Hiroki , Hamani Clement , Lozano Andres
Published: January 2008

Deep brain stimulation (DBS) has become a mainstay of treatment for patients with movement disorders. This modality is directed at modulating pathological activity within basal ganglia output structures by stimulating some of their nuclei, such as the subthalamic nucleus (STN) and the globus pallidus internus (GPi), without making permanent lesions. With the accumulation of experience, indications for the use of DBS have become clearer and the effectiveness and limitations of this form of therapy in different clinical conditions have been better appreciated. In this review the authors discuss the efficacy of DBS in the treatment of dystonia and levodopa-induced dyskinesias. The use of DBS of the STN and GPi is very effective for the treatment of movement disorders induced by levodopa. The relative benefits of using the GPi as opposed to the STN as a target are still being investigated. Bilateral GPi stimulation is gaining importance in the therapeutic armamentarium for the treatment of dystonia. The DYT1 forms of generalized dystonia and cervical dystonias respond to DBS better than secondary dystonia does. Discrimination between the diverse forms of dystonia and a better understanding of the pathophysiological features of this condition will serve as a platform for improved outcomes.
The Canadian multicenter trial of pallidal deep brain stimulation for cervical dystonia: preliminary results in three patients
Authors: Kiss Zelma H. T. , Doig Kristina , Eliasziw Michael , Ranawaya Ranjiit , Suchowersky Oksana
Published: January 2008

Object

Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is beneficial for generalized dystonia and has been proposed as a treatment for cervical dystonia. The Canadian Stereotactic/Functional and Movement Disorders Groups designed a pilot project to investigate the following hypothesis: that bilateral DBS of the GPi will reduce the severity of cervical dystonia at 1 year of follow up, as scored in a blinded fashion by two neurologists using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). Secondary outcome measures included pain and disability subscores of the TWSTRS, Short Form–36 quality of life index, and the Beck Depression Inventory.

Methods

Three patients have undergone surgery in Calgary with a followup duration of 7.4 ± 5.9 months (mean ± standard deviation). One patient underwent inadvertent ineffective stimulation for the first 3 months and did not experience a benefit until DBS programming was corrected. All three patients had rapid response to stimulation, with the muscles relaxing immediately and abnormal movements improving within days. Total TWSTRS scores improved by 79%, and severity subscores improved significantly, from 15.7 ± 2.1 to 7.7 ± 2.9 (paired ttest, p = 0.02). Pain and disability subscores improved from 25.5 ± 4.1 to 3.3 ± 3.1 (paired ttest, p = 0.002) and from 13.3 ± 4.9 to 3.3 ± 4.2 (paired ttest, p = 0.06), respectively.

Conclusions

Although it is too early to reach broad conclusions, this report of preliminary results confirms the efficacy of DBS of the GPi for cervical dystonia.
Stereotactic radiosurgery in patients with glomus jugulare tumors
Authors: Pollock Bruce E.
Published: January 2008

Object

Microsurgical removal of glomus jugulare tumors is frequently associated with injury of the lower cranial nerves. To decrease the morbidity associated with tumor management in these patients, gamma knife surgery (GKS) was performed as an alternative to resection.

Methods

Between 1990 and 2003, 42 patients underwent GKS as the primary management (19 patients) or for recurrent glomus jugulare tumors (23 patients). Facial weakness and deafness were more common in patients with recurrent tumors than in those in whom primary GKS was performed (48% compared with 11%, p = 0.02). The mean tumor volume was 13.2 cm3; the mean tumor margin dose was 14.9 Gy. The mean follow-up period for the 39 patients in whom evaluation was possible was 44 months (range 6–149 months). After GKS, 12 tumors (31%) decreased in size, 26 (67%) were unchanged, and one (2%) grew. The patient whose tumor grew underwent repeated GKS. Progression-free survival after GKS was 100% at 3 and 7 years, and 75% at 10 years. Six patients (15%) experienced new deficits (hearing loss alone in three, facial numbness and hearing loss in one, vocal cord paralysis and hearing loss in one, and temporary imbalance and/or vertigo in one). In 26 patients in whom hearing could be tested before GKS, hearing preservation was achieved in 86 and 81% at 1 and 4 years posttreatment, respectively. No patient suffered a new lower cranial nerve deficit after one GKS session; the patient in whom repeated GKS was performed experienced a new vocal cord paralysis 1 year after his second procedure.

Conclusions

Gamma knife surgery provided tumor control with a low risk of new cranial nerve injury in early follow-up review. This procedure can be safely used as a primary management tool in patients with glomus jugulare tumors that do not have significant cervical extension, or in patients with recurrent tumors in this location.
Efficacy and safety of stereotactic radiosurgery for glomus jugulare tumors
Authors: Lim Michael , Gibbs Iris C. , Adler John R. , Chang Steven D.
Published: January 2008

Object

Since the mid-1990s the use of radiosurgery for glomus jugulare tumors has grown in popularity. Despite its increased use, follow-up periods for radiosurgery are short and the numbers of patients reported are small. To add to the available information, the authors report their experience with the application of linear accelerator (LINAC) or CyberKnife modalities in 13 patients with 16 tumors.

Methods

All patients were treated with frame-based LINAC or CyberKnife radiosurgery, with doses ranging from 1400 to 2700 cGy. Patients were retrospectively assessed for posttreatment side effects, which included hearing loss, tongue weakness, and vocal hoarseness. The patients' most recent magnetic resonance (MR) images were also assessed for changes in tumor size.

The median follow-up duration was 41 months and the mean follow-up period was 60 months. All tumors remained stable or decreased in size on follow-up MR images. All patients had stable neurological symptoms, and one experienced transient ipsilateral tongue weakness and hearing loss, both of which subsequently resolved. One patient experienced transient ipsilateral vocal cord paresis; however, this individual had received previous external-beam radiation therapy.

Conclusions

The authors' findings continue to support radiosurgery as an effective and safe method of treatment for glomus jugulare tumors that results in low rates of morbidity.
Glomus jugulare tumors with intracranial extension
Authors: Jackson C. Gary , Kaylie David M. , Coppit George , Gardner Edward K.
Published: January 2008

Glomus tumors provide unique surgical challenges for both tumor resection and defect reconstruction. Tumors with intracranial extension compound these challenges. Surgical techniques have evolved, and now, with a multidisciplinary team, single-stage surgeries are the standard. In this paper the authors will report the results of the Otology Group protocol for surgical management of glomus tumors with intracranial extension. Particular attention will be paid to prevention of cerebrospinal fluid leaks with the use of vascularized tissue for defect reconstruction.
Historical review of cervical arthroplasty
Authors: Le Hoang , Thongtrangan Issada , Kim Daniel H.
Published: January 2008

Early attempts at spinal arthroplasty in the 1950s yielded limited success. A revival of this procedure occurred in the 1980s and became a realistic treatment option in the 1990s. Both lumbar and cervical arthroplasties have been introduced in the US since 2000 for randomized, prospective studies in accordance with the Food and Drug Administration (FDA) investigational device exemption provisions. In June 2004 the first lumbar arthroplasty device was approved by the FDA for use in the US. It is likely that cervical arthroplasty will soon follow and may be available for widespread use as early as 2006. In this paper the authors review the historical development of cervical arthroplasty.
Long-term outcome after implantation of the Prestige I disc in an end-stage indication: 4-year results from a pilot study
Authors: Robertson James T. , Metcalf Newton H.
Published: January 2008

Object

The long-term function of an artificial cervical disc device is critical to its clinical success. The Prestige I Cervical Disc System has been used clinically since June 1998, and long-term results can now begin to be assessed. The authors conducted clinical and radiographic examinations at 3 and 4 years postoperatively to evaluate the long-term performance of the Prestige I device.

Methods

A pilot trial was initiated in which the Prestige I disc was implanted in a cohort of patients with end-stage disease, who often had a history of multiple previous fusion procedures. All patients were followed according to a standardized clinical and radiographic protocol until 2 years postoperatively. Outcome measures included the Short Form–36 (SF-36) and Neck Disability Index (NDI) questionnaires, neurological status, and radiographic status. To evaluate the long-term function of the device, Ethics Committee approval was obtained to assess the patients at 3 and 4 years postoperatively. All patients were contacted, and after signing an additional informed consent document, were reevaluated according to the standardized protocol.

Of the 17 patients in the original cohort, 13 were evaluated at 3 years and 14 were evaluated at 4 years postoperatively. Clinical outcome measures including the NDI and SF-36 showed good improvement, especially when the end-stage nature of the disease is considered. Radiographic analysis showed that the Prestige I disc maintained motion at the treated segment at 3 and 4 years postoperatively.

Conclusions

In this report the authors demonstrate the clinical viability of the Prestige I cervical disc system at long-term postoperative intervals, even in the more severe biomechanical environment of end-stage disease.
An improved biomechanical testing protocol for evaluating spinal arthroplasty and motion preservation devices in a multilevel human cadaveric cervical model
Authors: DiAngelo Denis J. , Foley Kevin T.
Published: January 2008

Object

An experimental study was performed to determine the biomechanical end-mounting configurations that replicate in vivo physiological motion of the cervical spine in a multiple-level human cadaveric model. The vertebral motion response for the modified testing protocol was compared to in vivo motion data and traditional pure-moment testing methods.

Methods

Biomechanical tests were performed on fresh human cadaveric cervical spines (C2–T1) mounted in a programmable testing apparatus. Three different end-mounting conditions were studied: pinned–pinned, pinned–fixed, and translational/pinned–fixed. The motion response of the individual segmental vertebral rotations was statistically compared using one-way analysis of variance and Student-Newman-Keuls tests (p < 0.05 unless otherwise stated) to determine differences in the motion responses for different testing methods.

Conclusions

A translational/pinned–fixed mounting configuration induced a bending-moment distribution across the cervical spine, resulting in a motion response that closely matched the in vivo case. In contrast, application of pure-moment loading did not reproduce the physiological response and is less suitable for studying disc arthroplasty and nonfusion devices.
Effects of a cervical disc prosthesis on segmental and cervical spine alignment
Authors: Pickett Gwynedd E. , Mitsis Demytra K. , Sekhon Lali H. , Sears William R. , Duggal Neil
Published: January 2008

Object

Cervical arthroplasty offers the promise of maintaining motion of the functional spinal unit (FSU) after anterior cervical discectomy. The impact of cervical arthroplasty on sagittal alignment of the FSU needs to be addressed, together with its effect on overall sagittal balance of the cervical spine.

Methods

The authors prospectively reviewed radiographic and clinical outcomes in 14 patients who received the Bryan Cervical Disc prosthesis (Medtronic Sofamor Danek, Memphis, TN), for whom early (< 6 months) and late (6–24 months) follow-up data were available. Static and dynamic radiographs were measured by hand and computer to determine the angles formed by the endplates of the natural disc preoperatively, those formed by the shells of the implanted prosthesis, the angle of the FSU, and the C2–7 Cobb angle. The range of motion (ROM) was also determined radiographically, whereas clinical outcomes were assessed using the Neck Disability Index (NDI), and Short Form–36 (SF-36) questionnaires.

The ROM was preserved following surgery, with a mean preoperative sagittal rotation angle of 8.96°, which was not significantly different from the late postoperative value of 8.25°. When compared with the preoperative disc space angle, the shell endplate angle in the neutral position became kyphotic in the early and late postoperative periods (mean change −3.8° in the late follow-up period; p = 0.0035). The FSU angles also became significantly more kyphotic post-operatively, with a mean change of −6° (p = 0.0006). The Cobb angles varied widely preoperatively and did not change significantly after surgery. There was no statistical correlation between the NDI and SF-36 outcomes and cervical kyphosis.

Conclusions

Cervical arthroplasty preserves motion of the FSU. Both the endplate angle of the treated disc space and the angle of the FSU became kyphotic after insertion of the Bryan prosthesis. The overall sagittal balance of the cervical spine, however, was preserved.
In vitro biomechanics of cervical disc arthroplasty with the ProDisc-C total disc implant
Authors: DiAngelo Denis J. , Foley Kevin T. , Morrow Brian R. , Schwab John S. , Song Jung , German John W. , Blair Eve
Published: January 2008

An in vitro biomechanical study was conducted to compare the effects of disc arthroplasty and anterior cervical fusion on cervical spine biomechanics in a multilevel human cadaveric model. Three spine conditions were studied: harvested, single-level cervical disc arthroplasty, and single-level fusion. A programmable testing apparatus was used that replicated physiological flexion/extension, lateral bending, and axial rotation. Measurements included vertebral motion, applied load, and bending moments. Relative rotations at the superior, treated, and inferior motion segment units (MSUs) were normalized with respect to the overall rotation of those three MSUs and compared using a one-way analysis of variance with Student–Newman–Keuls test (p < 0.05). Simulated fusion decreased motion across the treated site relative to the harvested and disc arthroplasty conditions. The reduced motion at the treated site was compensated at the adjacent segments by an increase in motion. For all modes of testing, use of an artificial disc prosthesis did not alter the motion patterns at either the instrumented level or adjacent segments compared with the harvested condition, except in extension.
Cervical arthroplasty in the management of spondylotic myelopathy: 18-month results
Authors: Sekhon Lali H. S.
Published: January 2008

Object

Cervical spinal cord compression managed via an anterior approach with an arthrodesis may be associated with a decreased range of motion and accelerated adjacent-segment degeneration. Artificial cervical disc replacement may address these problems.

Methods

The author presents a series of 11 patients (seven men and four women, ages 31–55 years) with anterior cervical decompression and placement of a total of 15 artificial disc prostheses. Clinical and radiological follow-up review was performed at 24 hours, 6 weeks, 3 months, 6 months, and then yearly (mean follow-up period 18.4 months, range 10–32 months). There were no major complications. There was an improvement in the Nurick grade by 0.91 grades (p < 0.001) and in the Oswestry Neck Disability Index by 41.5 percentage points (p < 0.001). In one case fusion was attained at 17 months postoperatively and one patient had a transient worsening of preoperative symptoms postoperatively, with focal kyphosis. The spinal cord was decompressed on postoperative imaging in all cases.

Conclusions

Cervical arthroplasty after anterior cervical decompression at one or more levels represents an exciting tool in the management of spinal cord compression caused by spondylotic disease or acute disc prolapse. Results obtained in this study add further weight to the potential role of cervical arthroplasty for cervical myelopathy and longer follow up is provided on a previously reported series. It is suggested that care must be taken in using this unconstrained prosthesis if there is a preexisting spinal deformity. Longer follow up will reveal any delayed problems with artificial disc implantation, but in the short to medium term, this technique offers an excellent outcome.
Prophylaxis for deep venous thrombosis in neurosurgical oncology: review of 2779 admissions over a 9-year period
Authors: Smith Sarah F. , Simpson Judy M. , Sekhon Lali H.S.
Published: January 2008

Object

Management of disease in patients undergoing neurosurgical treatment for tumors requires balancing the competing risks of hemorrhage and thrombosis. The authors compared the incidence of clinically apparent deep venous thrombosis (DVT) and pulmonary embolism (PE) in patients admitted for treatment of intracranial and spinal tumors at three institutions. At the public hospital (the Royal North Shore Hospital [RNSH]) nonsequential calf compression was used, and at the other two private neurosurgery services sequential calf compression with low-molecular-weight heparin was used in patients undergoing spinal surgery. All patients wore compression stockings and underwent follow-up scanning after surgery.

Methods

The authors identified from their neurosurgery databases 2779 discharges of patients with tumor from the RNSH and private hospitals between January 1, 1995 and December 31, 2003. Patient admissions were relatively well matched for age, sex, duration of stay, and tumor type. For patients who underwent spinal surgery, the incidence of DVT was higher in the RNSH (2.6% of admissions) than in private hospitals, where no case of DVT was seen (p = 0.02). The incidence of PE was higher in admissions patients who had been treated for cranial tumors in the RNSH (2.9%) than in those treated in the private hospitals (1.3%, p = 0.01).

Possible reasons for these discrepancies include a higher proportion of ambulatory patients before and after surgery in the group treated at private hospitals. More emergency and semi-emergency surgery was performed in the RNSH than in the private hospitals. Nevertheless, fewer patients discharged from the RNSH had undergone surgery, which is a known risk factor for DVT.

Conclusions

Patients with intracranial tumors had a higher incidence of PE than those with spinal tumors. The incidence of DVT and PE was higher in patients admitted to the public hospital. The incidence of DVT in patients undergoing spinal procedures was lower when low-molecular-weight heparin was used judiciously, but the incidence of PE in patients undergoing cranial procedures was lower with the private hospital protocol, which did not include prophylaxis with anticoagulating agents.
Prophylactic placement of an inferior vena cava filter in high-risk patients undergoing spinal reconstruction
Authors: Rosner Michael K. , Kuklo Timothy R. , Tawk Rabih , Moquin Ross , Ondra Stephen L.
Published: January 2008

Object

The purpose of this study was to evaluate the safety and efficacy of prophylactic inferior vena cava (IVC) filter placement in high-risk patients who undergo major spine reconstruction.

Methods

In the pilot study, 22 patients undergoing major spine reconstruction received prophylactic IVC filters. These patients were prospectively followed to evaluate complications related to the filter, the rate of deep venous thrombosis (DVT) formation, and the rate of pulmonary embolism (PE). These data were compared with those obtained in a retrospective review for PE in a matched cohort treated at the same institution. At a second institution the treatment guidelines were implemented in 17 patients undergoing complex spine surgery with the same follow-up criteria.

In the pilot study, no patient experienced PE (0%), whereas two had DVT (9%). Bilateral DVT developed postoperatively in one patient (associated morbidity rate 4.5%), who required thrombolytic therapy. One patient died of unrelated surgical complications. The PE rate in the matched cohort at the same institution was 12%. At the second institution, no patient had PE, and no complications were noted.

Conclusions

In this patient population, prophylactic IVC filter placement appears to decrease the PE rate substantially, from 12 to 0%. The placement of IVC filters appears to be a safe and efficacious intervention for prevention of PE in high-risk patients.
Cavernous hemangioma of the skull presenting with subdural hematoma
Authors: Gottfried Oren N. , Gluf Wayne M. , Schmidt Meic H.
Published: January 2008

Cavernous hemangioma of the calvaria is a very rare disease, and patients usually present with headaches or a visible skull deformity. Few reports of patients presenting with intradiploic or epidural hemorrhages are found in the literature. No case of an intradural hemorrhage from a cavernous hemangioma of the skull has been reported to date. The authors present the case of a 50-year-old man in whom a symptomatic subdural hematoma (SDH) resulting from a cavernous hemangioma of the calvaria had hemorrhaged and eroded through the inner table of the skull and dura mater. The patient underwent surgery for evacuation of the SDH and resection of the calvarial lesion. Postoperatively, the patient experienced immediate relief of his symptoms and had no clinical or radiological recurrence. Calvarial cavernous hemangiomas should be considered in the differential diagnosis of nontraumatic SDHs. Additionally, skull lesions that present with intracranial hemorrhages must be identified and resected at the time of hematoma evacuation to prevent recurrences.
Combined endovascular and microsurgical management of giant and complex unruptured aneurysms
Authors: Ponce Francisco A. , Albuquerque Felipe C. , McDougall Cameron G. , Han Patrick P. , Zabramski Joseph M. , Spetzler Robert F.
Published: January 2008

Object

The purpose of this study was to assess the efficacy and describe the technical features of combined endovascular and microsurgical treatments for complex and giant unruptured intracranial aneurysms.

Methods

A prospectively maintained database was reviewed to identify all patients with unruptured intracranial aneurysms who were treated with combined techniques. Twenty-one lesions were treated in as many patients: six lesions involved the posterior cerebral artery (PCA); seven the cavernous portion of the internal carotid artery (ICA); two the basilar apex; two the basilar trunk; and one each the anterior communicating artery, anterior cerebral artery, petrous ICA, and cervical ICA. Aneurysms were treated with combined extracranial–intracranial bypass procedures and parent-vessel occlusion, flow redirection, or arterial transposition.

Aneurysm occlusion was achieved in 20 patients. In the remaining patient the aneurysm recurred, requiring stent-assisted repeated coil placement. Three patients suffered permanent neurological deficits related to treatment, and three died, two of whom had basilar trunk aneurysms.

Conclusions

Certain complex aneurysms may be treated optimally by combining endovascular and surgical procedures. A low incidence of complications follows treatment of anterior circulation aneurysms. Treatment of complex posterior circulation aneurysms is associated with a higher incidence of complications, although this likely reflects the more complex nature of these lesions. The risks of this combined treatment strategy are likely lower than the risks associated with the natural history of this subset of aneurysms.
The natural history of unruptured intracranial aneurysms
Authors: Mocco J , Komotar Ricardo J. , Lavine Sean D. , Meyers Philip M. , Connolly E. Sander , Solomon Robert A.
Published: January 2008

Since the publication of preliminary results from the International Study of Unruptured Intracranial Aneurysms in 1998 there has been a great deal of debate concerning the natural history of these lesions and their attendant risk of aneurysmal subarachnoid hemorrhage. Therefore, the authors reviewed a selected number of crucial studies concerning this topic to determine the best evidence-based estimate of a rupture rate for these lesions. Based on this analysis, the yearly risk of bleeding for an unruptured intracranial aneurysm is estimated to be approximately 1% for aneurysms 7 to 10 mm in diameter. This risk of rupture increases with aneurysm size and it likewise diminishes as the size of the lesion decreases. This general rule serves as a reasonable interpretation of the results reported in the current body of literature.
Spinal epidural abscess: appearance on magnetic resonance imaging as a guide to surgical management
Authors: Parkinson Jonathon F. , Sekhon Lali H. S.
Published: January 2008

Spinal epidural abscess is associated with considerable rates of morbidity and mortality despite its infrequent occurrence. Advances in magnetic resonance (MR) imaging technology have allowed easier diagnosis of this potentially devastating condition. It is also possible to predict the intraoperative appearance of each case of spinal epidural abscess prior to the procedure, based on the MR findings. Surgical treatment of this condition usually involves extensive decompressive laminectomy, which predisposes patients to spinal instability and deformity. Recent advances in surgical approaches to spinal epidural abscess have included the institution of less invasive techniques to manage this condition, including saline washes of the epidural space through catheters introduced via limited laminotomy. The cases reported here illustrate the ability to predict the intraoperative findings in patients with spinal epidural abscess, and to adjust the surgical approach accordingly to minimize the extent of potentially destabilizing procedures without impinging on the effectiveness of treatment.