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Biomedical subjects

Nancy E Epstein

Publications and source records attributed to Nancy E Epstein.

At least 19 recordsLinked to original sources

Impact of intraoperative normovolemic hemodilution on transfusion requirements for 68 patients undergoing lumbar laminectomies with instrumented posterolateral fusion.

STUDY DESIGN: To determine whether the normovolemic hemodilution (NH) technique would limit postoperative homologous blood transfusion requirements in 68 patients having multilevel lumbar laminectomies (3-6 levels) with predominant 1- or 2-level instrumented fusions. OBJECTIVE: In this setting, to define postoperative homologous blood transfusion requirements using NH. SUMMARY OF BACKGROUND DATA: NH limits postoperative homologous blood transfusion requirements following various types of surgical procedures including those on the spine. METHODS: NH was used in an attempt to limit postoperative homologous transfusion requirements in 68 patients undergoing lumbar surgery. NH involves the removal of 1 to 2 U of blood replaced with crystalloid (2-4 mL per milliliter of blood harvested). Multiple variables contributing to homologous transfusion requirements were analyzed. RESULTS: Using NH, no homologous blood transfusions were required in 52 patients with a mean preoperative hematocrit of 41.3 undergoing average 3.7 level laminectomies with 1.5 level fusions. However, 16 patients with an average preoperative hematocrit of 38.5 undergoing average 4.3 level laminectomies with 1.6 level fusions required transfusion of 31 U of homologous blood after surgery. CONCLUSIONS: Using NH, 16 (23.5%) patients required 31 postoperative homologous blood transfusions. By contrast, the remaining 52 patients with similar procedures were able to avoid the use of homologous transfusion.

Adult↗

Short Form-36 outcomes following focal 1- and 2-level cervical laminectomy with multilevel instrumented fusion.

BACKGROUND: Multilevel laminectomy with instrumented fusion addresses diffuse dorsal cord compression with an adequately preserved cervical lordosis. However, for patients with only 1 to 2 laminar impingement, more "focal" laminectomy and fusion may suffice, the shortened laminectomy allowing for a more simple spinous process fusion skipping the 1 or 2 lamina that have been removed. METHODS: Fourteen patients presented with severe spastic myeloradiculopathy (Nurick grade IV) attributed to magnetic resonance imaging- and CT-documented 1- to 2-level laminar compression, stenosis, and ossification of the yellow ligament. Magnetic resonance images also revealed 1- to 2-level hyperintense signals within the cord at the levels of maximal compromise. Surgical procedures included 1- to 2-level laminectomies and average 6.4-level posterior fusions. Dynamic x-ray/CT studies, which were obtained 3, 6, and up to 12 months postoperatively, followed progression toward fusion. Outcomes were assessed using Nurick grades (0-V) and SF-36 questionnaires assessed preoperatively and up to 12 months postoperatively. RESULTS: Patients improved on all 8 SF-36 Health Scales within the first postoperative year. Maximal improvement was observed on 5 Health Scales within the first 6 postoperative months (physical function, mental health, vitality, general health, role physical). The preoperative average Nurick grade (3.8) improved postoperatively (0.7 at 6 months, 0.5 at 1 year). Dynamic x-ray and CT studies documented fusion for all 14 patients by the sixth postoperative month. CONCLUSIONS: One- and two-level cervical laminectomies with multilevel-instrumented fusion effectively decompressed "focal" cord compression, whereas fusion maintained the cervical lordotic curvature and provided stability to avert future disease progression.

Adult↗

A preliminary study of the efficacy of Beta Tricalcium Phosphate as a bone expander for instrumented posterolateral lumbar fusions.

The associated morbidity of allograft(s) as bone graft expanders in spinal surgery has prompted the search for alternatives. The efficacy of Vitoss/Beta Tricalcium Phosphate (B-TCP: OrthoVita, Malvern PA, USA), an artificial bone substitute, combined with lamina autograft (50:50 mix) in 40 prospective posterolateral fusions utilizing pedicle/screw instrumentation was analyzed. Multilevel lumbar laminectomies (average 3.7 levels) were accompanied by 1 (27 patients) and 2 level (13 patients) fusions. Two neuroradiologists independently assessed fusion progression on dynamic x-rays and 2D-CT studies performed at 3, 6, and up to 12 months postoperatively. Outcomes were quantified utilizing Odom Criteria and Short-Form 36 (SF-36) questionnaires (preoperatively; and 3, 6, and 12 months postoperatively). By the sixth postoperative month, fusion was neuroradiologically confirmed on both dynamic x-rays and CT studies for 26 of 27 single level fusions (1 pseudarthrosis), and 11 of 13 two level fusions (L4-S1). Odom Criteria 3, 6, and 12 months postoperatively revealed continued improvement for all patients. SF-36 outcomes, however, revealed deterioration on 2 Health Scales (Role Physical, Role Emotional) 3 and 6 months post-operatively, and minimal to marked improvement on 6 Health Scales (PF, V, PF, V, SF, BP). Twelve months postoperatively improvement occurred on all 8 Health Scales, exceeding pre-operative baselines; minimal (RP, GH), mild (MH), moderate (PF, BP, V, SF), and marked improvement (RE). Although Vitoss/B-TCP and laminar autograft resulted in pseudarthrosis for 1 of 27 single level and 2 of 13 two level posterolateral instrumented lumbar fusions, only 1 of the latter patients required a secondary fusion.

Adult↗

Efficacy of pneumatic compression stocking prophylaxis in the prevention of deep venous thrombosis and pulmonary embolism following 139 lumbar laminectomies with instrumented fusions.

OBJECTIVE: Low-dose heparin (LDH) regimens reduce the frequency of deep venous thrombosis (DVT) and pulmonary embolism (PE) in spinal surgery but pose a risk of postoperative hemorrhage threatening neurologic function. Pneumatic compression stocking (CS) could provide an alternative means of mechanical prophylaxis alone against DVT and PE and would possibly avoid its hemorrhagic complications. METHODS: The efficacy of CS alone in preventing DVT and PE was evaluated in 139 patients undergoing multilevel lumbar laminectomies (average 3.8 levels) with instrumented fusions (average 1.4 levels). All patients received CS stocking prophylaxis intraoperatively and throughout the average 5-day postoperative course including following ambulation. Doppler screening for DVT was routinely performed 2 days postoperatively. Subsequent Doppler studies or computed tomography angiograms were selectively performed in symptomatic patients with potential DVT/PE. RESULTS: Four (2.8%) patients developed DVT 2-6 days postoperatively and required inferior vena cava (IVC) filters. One of the four had a positive routine screening Doppler study performed the second postoperative day. Two developed DVT the fourth postoperative day. The fourth patient developed DVT 6 days postoperatively but 3 weeks later embolized around the IVC filter. This patient, the only one to develop a PE, tested positive for Factor V Leiden mutation (hypercoagulable syndrome) and remains on long-term warfarin. CONCLUSIONS: Pneumatic compression stocking prophylaxis effectively reduced the incidence of DVT (2.8%) and PE (0.7%) in 139 patients undergoing multilevel lumbar laminectomies with instrumented fusions. These rates compared favorably with those reported in spinal series employing LDH prophylaxis.

Adult↗

Intermittent pneumatic compression stocking prophylaxis against deep venous thrombosis in anterior cervical spinal surgery: a prospective efficacy study in 200 patients and literature review.

STUDY DESIGN: Intermittent pneumatic compression stockings (IPC) alone were prospectively used to avoid deep venous thrombosis (DVT) and pulmonary embolism (PE) in 100 consecutive patients undergoing single-level anterior corpectomy/fusion (ACF) and in 100 patients having multilevel ACF/posterior fusion. OBJECTIVES: To determine the optimal prophylaxis against DVT and PE for patients undergoing anterior cervical spinal surgery. BACKGROUND DATA: Mini-heparin and low-dose heparin prophylaxis in neurosurgery poses a 2% to 4% risk of major postoperative hemorrhage with resultant neurologic sequelae. METHODS: Prophylaxis consisted of IPC alone. Doppler studies of the lower extremities were routinely obtained 2 days after surgery. Single-level ACF (100 patients) addressed two-level disc disease, spondylostenosis, and ossification of the posterior longitudinal ligament (OPLL). One hundred patients undergoing multilevel ACF (3+ levels) with posterior fusion (C2-T1) exhibited OPLL/spondylostenosis. RESULTS: One patient undergoing single-level ACF developed DVT/PE 6 days after surgery; she exhibited Factor V Leiden mutation (hypercoagulability syndrome). Although 7 patients undergoing circumferential surgery developed DVT 2 to 14 days following surgery (mean, 7.15 days), only two clots localized in the iliac veins resulted in PEs (days 10 and 14 after surgery). CONCLUSIONS: IPCs were as effective for prophylaxis against DVT/PE for 100 patients undergoing single-level ACF and for 100 having circumferential procedures as existing therapies (mini-heparin and low-dose heparin), without the risk of hemorrhage. However, the 1% and 2% respective rates of PE were comparable to frequencies of PE encountered in other cranial/spinal series using mini-heparin and/or low-dose heparin regimens but avoided the 2% to 4% risk of major postoperative hemorrhage.

Bandages↗

A review of the risks and benefits of differing prophylaxis regimens for the treatment of deep venous thrombosis and pulmonary embolism in neurosurgery.

BACKGROUND: Annually, 2 million people in the United States develop deep venous thrombosis (DVT), and nearly 100,000 sustain fatal pulmonary emboli. Prophylaxis against DVT/pulmonary embolism (PE) is a critical issue, and options include elastic stockings, intermittent pneumatic compression stockings, low-dose unfractionated heparin (5000 U every 8-12 hours), and low molecular-weight heparin (ie, enoxaparin and dalteparin). The risks and benefits associated with different prophylaxis regimens used in the prevention of DVT and PE in neurosurgical procedures were analyzed. METHODS: Neurosurgical studies focusing on different methods of prophylaxis used for the prevention of DVT and PE were reviewed. The efficacy, risks, and benefits of varied treatment options were evaluated, with particular emphasis on minor and major hemorrhages occurring where heparin-based protocols were used. RESULTS: In Flinn et al series (Arch Surg. 1996;131(5):472-80), the incidence of DVT was greater for cranial (7.7%) than spinal procedures (1.5%). Although intermittent pneumatic compression devices provided adequate reduction of DVT/PE in some cranial and combined cranial/spinal series, low-dose subcutaneous unfractionated heparin or low molecular-weight heparins further reduced the incidence, not always of DVT, but of PE (Br J Neurosurg 1995;9(2):159-63; J Intensive Care Med 2003;18(2):59-79). Nevertheless, low-dose heparin-based prophylaxis in cranial and spinal series risks minor and major postoperative hemorrhages: 2% to 4% in a cranial series, 3.4% minor and 3.4% major hemorrhages in a combined cranial/spinal series, and a 0.7% incidence of major/minor hemorrhages in a spinal series (J Neurosurg 2003;99(4):680-4; Neurosurgery 1986;18(4):440-5; Eur Spine J 2004;13(1):1-8; J Intensive Care Med 2003;18(2):59-79). CONCLUSIONS: Although mechanical prophylaxis provided effective prophylaxis against DVT/PE in many series, the added efficacy of low-dose heparin regimens has to be weighed against risks of major postoperative hemorrhages and their neurological sequelae.

Bandages↗

Clear cell meningioma of the cauda equina in an adult: case report and literature review.

In the pediatric population, clear cell meningiomas are more frequently intracranial than intraspinal in location. Tumors recur in up to 40% of cases within 15 postoperative months and are often managed with repeated resection with or without radiation therapy. The management strategy for adults with clear cell meningiomas involving the lumbar spinal canal (cauda equina) is less clearly defined. A 41-year-old woman presented with mild, right greater than left, lower extremity paresis. An enhanced magnetic resonance (MR) scan revealed a homogeneously enhancing intradural lesion filling the spinal canal at the L3-L4 level. Preoperative noncontrast MR studies of the brain and cervical and thoracic spine were negative. An L2-L5 laminectomy was performed for gross total excision of the intradural lesion, which was adherent to one nerve root of the cauda equina. Frozen-section diagnosis confirmed clear cell tumor. Differential diagnoses included meningioma versus renal cell carcinoma. Negative postoperative chest, abdominal, and pelvic computed tomography studies ruled out tumor of renal cell origin. Enhanced MR studies of the neuraxis proved negative. Consultations with multiple oncologists and radiation therapists recommended neither radiation nor chemotherapy following this initial surgery. She remains disease-free 1 year postoperatively. The high recurrence rate for clear cell meningiomas in children requires repeated tumor resection with or without secondary radiation therapy. Following gross total resection of lumbar tumors in adults, reserving radiation therapy for secondary recurrences provides optimal management.

Adult↗

Circumferential cervical surgery for ossification of the posterior longitudinal ligament: a multianalytic outcome study.

STUDY DESIGN: Three outcome measures, Nurick grades, Odom's criteria, and the Short Form (SF-36) were analyzed following circumferential cervical surgery in 47 patients. OBJECTIVES: To analyze three outcome measures following circumferential surgery. SUMMARY OF BACKGROUND DATA: Few studies use multiple outcome criteria to assess circumferential surgery. METHODS: Patients averaged 54 years of age and exhibited severe myelopathy (Nurick grade 3.6). Corpectomies of 2.6 vertebrae (on average) were followed by posterior fusions (C2-T1) with halo stabilization. Initial fixed-plates (n = 28) and subsequent dynamic ABC plates (Aesculap, Tuttlingen, Germany) (n = 19) were applied, Fusion was confirmed on dynamic radiographs and two-dimensional CT studies 3, 6, and up to 12 months after surgery. Nurick grades and Odom's criteria were evaluated 1 and 2 years after surgery. Results of SF-36 questionnaires, obtained before surgery, 6 weeks, 3 months, 6 months, 1 year, 2 years after surgery, were calculated. RESULTS: Neurodiagnostic studies confirmed fusion on average 5.0 months after surgery. One and 2 years after surgery, mean Nurick grades were 0.8 (+2.8 points) and 0.4 (+3.2 points), respectively. One year (2 years) postoperative Odom's criteria revealed excellent 26 (30), good 14 (11), fair 6 (5), and poor 1 (1) patient outcomes. Comparing preoperative with 1-year postoperative SF-36 questionnaires revealed moderate improvement on 5 health scales: Social Function (+19.9), Bodily Pain (+19.6), Role-Physical (+18.8), Physical Function (+12.5), and Role-Emotional (+11.1). Minimal additional improvement occurred over the second year: Role-Physical (+21.6), Social Function (+16.4), Bodily Pain (+13.4), Physical Function (+12.8), and Role Emotional (+9.5). CONCLUSION: Based on three outcome measures, the greatest improvement occurs 1 year following circumferential surgery.

Adult↗

Lumbar laminectomy for the resection of synovial cysts and coexisting lumbar spinal stenosis or degenerative spondylolisthesis: an outcome study.

STUDY DESIGN: Surgeon- and patient-based (SF-36) outcome measures were used to assess the results of decompressive laminectomies for the excision of synovial cysts with coexistent lumbar spinal stenosis (45 patients) or for synovial cysts with coexistent lumbar stenosis and degenerative spondylolisthesis (35 patients). OBJECTIVES: To evaluate the results following laminectomy and the excision of synovial cysts/stenosis with or without olisthy. SUMMARY OF BACKGROUND DATA: SF-36 outcome studies evaluating these surgical results deserve further investigation. METHODS: Before surgery, patients with synovial cysts/ stenosis (45 patients) or cysts/stenosis/degenerative spondylolisthesis (35 patients), respectively, exhibited low back pain (40 and 33 patients), radiculopathy (43 and 33 patients), and neurogenic claudication (41 and 26 patients). Surgery required average 3.8 and 3.5 level laminectomies, respectively, for patients with cysts/stenosis and cysts/stenosis and olisthy. Outcomes were assessed 2 years after surgery. RESULTS: Five of 45 patients undergoing laminectomy alone for cysts/stenosis developed postoperative olisthy. Of 35 patients with cysts/stenosis and preoperative Grade 1 degenerative spondylolisthesis, olisthy increased after surgery to Grade 2 in 11 patients. Good/excellent results (58% and 63%) and SF-36 improvement on the Physical Function Scale (+44 and +38 points) were, respectively, documented for these two groups. CONCLUSIONS: Using both surgeon and SF-36 outcome measures, 2 years following laminectomy for synovial cysts/lumbar stenosis with or without olisthy, patients exhibited a moderate degree of improvement. As synovial cysts reflect disruption of the facet joint and some degree of instability, primary fusion should be considered to improve operative results for patients in both categories.

Aged↗

Lumbar synovial cysts: a review of diagnosis, surgical management, and outcome assessment.

Synovial cysts of the lumbar spine contribute significantly to narrowing of the spinal canal and lateral thecal sac and nerve root compression. Cysts form as a result of arthrotic disruption of the facet joint, leading to degenerative spondylolisthesis in up to 40% of patients. Clinical findings and neurodiagnostic confirmation prompt surgical intervention consisting of varying decompressions with or without primary fusion. Most patients present in their mid-60s, with a male-to-female ratio varying from 2:1 to 1:1. Preoperative symptoms include low back pain, radiculopathy, and neurogenic claudication. Motor and sensory signs usually reflect the anatomic location of the synovial cyst and the level of resultant maximal lumbar stenosis. In descending order of frequency, they are typically found at the L4-L5, L5-S1, L3-L4, and L2-L3 levels. Lumbar synovial cyst surgery includes unilateral or bilateral laminotomies, hemilaminectomies, or laminectomies alone or in combination with in situ or instrumented fusion. Those patients undergoing decompression alone may postoperatively develop progression or the new appearance of olisthy, while those primarily fused rarely show further increase or a new onset of slip. Outcome measures spanning 1- to 2-year postoperative intervals frequently included surgeon-based rather than the current patient-based analysis, the lat-ter including the Medical Outcomes Trust Short Form-36.

Humans↗

Posterior cervical fusion failure in three morbidly obese patients following circumferential surgery.

BACKGROUND: The stability of multilevel anterior corpectomy with fusion (ACF) is often enhanced by simultaneous posterior fusion (PF) which provides a "posterior tension band." Three morbidly obese patients undergoing circumferential surgery had posterior fusions performed without autogenous iliac crest graft to avoid donor site morbidity. METHODS: Three morbidly obese patients (300-350 lbs.), averaging 48 years of age, presented with rapidly progressive moderate/severe myelopathies. Magnetic resonance imaging (MRI) and computed tomography (CT) studies demonstrated severe ventral ossification of the posterior longitudinal ligament. Two to four level plated ACFs were performed utilizing fibula strut allograft and plates. Posterior spinous process wiring/fusion from C2-T1 were completed with braided titanium cables, fibula strut allografts, Inductive Conductive Matrix (a form of demineralized bone matrix), and allograft bone to avoid iliac crest donor site morbidity in such morbidly obese patients. Halo devices were utilized until fusion was documented on postoperative X-ray and 2D-CT studies subsequently obtained 3, 6, and up to 12 months postoperatively. Patients were followed an average of 3 years. RESULTS: Postoperatively, all 3 patients demonstrated mild residual myelopathy (Nurick Grade 0-I). Nevertheless, all 3 exhibited posterior pseudarthroses accompanied by anterior strut/plate extrusion (1 patient), partial anterior graft pseudarthrosis (1 patient), and a delayed strut fracture (1 patient). The first 2 patients required secondary posterior fusions performed with autogenous iliac crest graft, while the third fused with 6 months of additional bracing. CONCLUSIONS: Following circumferential cervical procedures, posterior fusions failed in 3 morbidly obese patients where iliac crest autograft was omitted in an attempt to avoid donor site morbidity.

Bone Plates↗

Does donor site reconstruction following anterior cervical surgery diminish postoperative pain?

Many attempts have been made at donor site reconstruction to reduce postoperative pain following anterior cervical surgery. This study is a comparative analysis of the outcome of 46 patients undergoing single-level anterior corpectomy and fusion using iliac crest autograft performed by one surgeon (N.E.E.). Twenty-three patients had no donor site reconstruction, whereas the more recent 23 patients had iliac crest reconstruction using a MacroPore sheet (MacroPore, Inc., San Diego, CA) and Inductive Conductive Matrix (ICM, Sofamor Danek, Memphis, TN). Bodily Pain, assessed on the Short Form-36, obtained up to 12 months postoperatively, failed to demonstrate better pain relief following donor site reconstruction. Multiplanar CT studies obtained 6 months postoperatively documented 100% donor site fusion for the 23 reconstructed patients. Although iliac crest reconstruction failed to reduce Bodily Pain, it did result in 100% fusion.

Adult↗

Documenting fusion following anterior cervical surgery: a comparison of roentgenogram versus two-dimensional computed tomographic findings.

Documentation of fusion following anterior cervical surgery may critically influence management strategies that can adversely affect outcome. Would two-dimensional CT studies more accurately identify fusion following single-level anterior corpectomy with fusion compared with radiographic studies (plain/dynamic) alone? To answer this question, two radiologists, in a "blinded" fashion, separately read both radiographic and two-dimensional CT studies obtained 3 and 6 months following 46 single-level anterior corpectomy with fusion. Single-level anterior corpectomy with fusion used nonreversed iliac crest strut autografts and dynamic ABC plates (Aesculap, Tuttlingen, Germany). Following surgery, patients were immobilized in cervicothoracic orthoses, which were discontinued when fusion was confirmed. Patients were followed an average of 3.2 years (minimum 2 years). Outcomes were measured with the Short Form-36 questionnaire administered preoperatively, and 3, 6, and 12 months postoperatively. Three months after surgery, radiographs documented fusion in 38 (83%) of 46 patients, whereas two-dimensional CTs confirmed fusion in only 23 (50%) of 46 patients. Six months postoperatively, radiographs documented fusion in 44 (96%) of 46 patients, whereas only 32 (70%) of 46 patients were solidly fused on two-dimensional CT studies. Three and 6 months following single-level anterior corpectomy with fusion, two-dimensional CT scans more accurately confirmed fusion compared with radiographs alone.

Adult↗

It is easier to confuse a jury than convince a judge: the crisis in medical malpractice.

STUDY DESIGN: A study of cervical spine malpractice cases was conducted. Identifying tort reform models may help to resolve a crisis in medical malpractice. OBJECTIVE: To identify tort reform models that may help to resolve a crisis in medical malpractice. SUMMARY OF BACKGROUND DATA: Medical malpractice faces a crisis. Insurance rates are exorbitant, yet many injured patients go uncompensated. Physicians practice defensive medicine for fear of suits, and society pays the price. METHODS: Using, 36 malpractice cases involving cervical spine surgery were identified: 20 from California ($250,000 cap on pain and suffering) and 16 from New York ("the sky's the limit"). Queries included who sued, who was sued, who won, who lost, and why? Six different tort reform models also were identified and explored. RESULTS: Common bases for suits included failure to diagnose and treatment (56%), lack of informed consent (64%), new neurologic deficits (64%), and pain and suffering (72%). All of the six plaintiff verdicts (average, $4.42 million) and four of the nine settlements (average, $1.6 million) involving surgery that resulted in new postoperative quadriplegia appeared to be appropriate. However, the author could discern "no fault" in cases five defendants had settled, and the surgeons did not deserve to lose. On the other hand, the author found "fault" in five defense verdicts rendered to three newly quadriplegic patients and two with new postoperative root injuries. These patients deserved monetary awards, but received no compensation whatsoever. There currently are two models that would work better than the system in place in most states. These include the American Medical Association National Specialty Societies Medical Liability Project with the Alternative Dispute Resolution Model (SSMLP), and the Selective No Fault Models. Among the advantages shared by one or more of these models is their ability to reimburse injured patients while eliminating physician liability, to use malpractice panels rather than trials, and to put a cap on damages. CONCLUSIONS: To solve the medical malpractice crisis, Congress, the individual states, or both should adopt tort reform. Two tort reform models compensating injured patients and eliminating physician liability appear to be not only effective but also fair to all concerned parties.

California↗

In vitro characteristics of cultured posterior longitudinal ligament tissue.

STUDY DESIGN: To determine the osteogenicity of posterior longitudinal ligament ossification, the posterior longitudinal ligament obtained during anterior cervical surgery from patients with the disorder was analyzed with in vitro cultures. OBJECTIVES: To determine the osteogenicity of the posterior longitudinal ligament. SUMMARY OF BACKGROUND DATA: The osteogenicity of posterior longitudinal ligament ossification in North America requires better documentation. METHODS: The posterior longitudinal ligament obtained during anterior cervical corpectomy with fusion from seven patients, three with ossification of the posterior longitudinal ligament documented by magnetic resonance imaging and computed tomography and four with spondylosis, was blindly submitted for in vitro culture. Explants of the posterior longitudinal ligament were placed in Dulbecco modified Eagle medium with 10% fetal calf serum, antibiotics, 4 mmol/L x L-proline, and 50 mg/L ascorbic acid. After reaching confluency, cells were trypsinized, and first-passage cells were used for all osteocalcin measurements to establish their osteoblastic phenotype. Periosteal cells, previously shown to synthesize osteocalcin, were used as a positive control. The cells were incubated with 1,25(OH)2 vitamin D3 at 10E-8 M for 72 hours in serum-free medium. The supernatants were collected and frozen, after which the quantity of osteocalcin induced by exposure to 1,25(OH)2 vitamin D3 was determined using enzyme-linked immunoassay. Control replicate cultures were measured without incubation using vitamin D3. RESULTS: Ossification of the posterior longitudinal ligament cell lines responded positively with osteocalcin synthesis in the 0.1 to 0.4 ng/M range. The cell line of the patient with spondylosis alone did not respond to vitamin D3 priming. CONCLUSIONS: Posterior longitudinal ligament cells from the three North American white patients with ossification of the posterior longitudinal ligament, when cultured in vitro, synthesized osteocalcin on vitamin D3 priming, confirming their osteoblastic phenotype, whereas posterior longitudinal ligament cells from four white patients with isolated spondylosis did not.

Calcitriol↗

A review of laminoforaminotomy for the management of lateral and foraminal cervical disc herniations or spurs.

BACKGROUND: Anterior versus posterior surgical management of lateral and foraminal cervical disc disease remains controversial. The key hole foraminotomy or laminoforaminotomy allows dorsal resection without the instability encountered with anterior cervical approaches, with more limited morbidity. Unilateral radiculopathy can be addressed with the laminoforaminotomy, while bilateral or multifocal radiculopathy with myelopathy may additionally require a laminectomy or laminoplasty. METHODS: Selection of patients for laminoforaminotomy should be based upon correlation of clinical findings and neurodiagnostic (MR, CT) studies to ensure that the dorsal approaches will sufficiently address the pathology. RESULTS: The technical completion of a laminoforaminotomy is reviewed. CONCLUSIONS: Performing adequate preoperative MR and CT examinations allows for the selection of patients who will benefit from the "key hole" or "laminoforaminotomy" approaches to lateral and foraminal disc disease and/or spur formation.

Cervical Vertebrae↗

Anterior dynamic plates in complex cervical reconstructive surgeries.

The aim of this work was to evaluate the efficacy of dynamic anterior cervical plates following one-level anterior corpectomy with fusion (ACF) (i.e., C5-7) and two- to four-level ACF with posterior wiring and fusion (PWF). Dynamic plates (ABC Aesculap, Tuttlingen, Germany), allowing for 10 mm of cephalad and 10 mm of caudad plate migration, were applied for one-level ACF (28 patients) and multilevel ACF/PWF (20 patients). Two (7%) dynamic plates failed after one-level ACF. One pseudarthrosis and one plate extrusion occurred, both in morbidly obese patients. No multilevel ACF/PWF failed. The 7% failure rate for dynamic plates applied for one-level ACF is somewhat high, whereas the 0% failure rate for multilevel ACF/PWF with halo immobilization proves more promising. Perhaps PWF with halo stabilization for morbidly obese individuals undergoing one-level ACF would avoid future plate-related problems.

Adult↗