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Biomedical subjects

T J Albert

Publications and source records attributed to T J Albert.

At least 37 records · Page 2Linked to original sources
PubMed1999

Transpedicle screw fixation of the cervical spine.

The use of posterior cervical spine fixation has become increasingly popular in recent years. Dissatisfaction with lateral mass fixation, especially at the cervicothoracic junction, has led spine surgeons to use cervical pedicle screw fixation for reconstruction in numerous cervical spine disorders. The biomechanical advantage of a three-column fixation device implanted to secure an unstable cervical spine has proven to be a valuable tool in the spine surgeon's armamentarium. Successful placement of a pedicle screw in the cervical spine requires a sufficient three-dimensional understanding of pedicle morphology to allow accurate identification of the ideal screw axis. Variability in cadaveric based morphometric measurements used to guide the surgeon in the placement of a pedicle screw has raised legitimate concerns as to whether transpedicle fixation can be applied without significant neurovascular complications. The emergence of computer assisted image guidance systems may be implemented in the operative protocol to improve the accurate placement of a pedicle screw. The indications for placement of a pedicle screw in the cervical spine are beginning to evolve. Only surgeons experienced in transpedicle screw fixation and surgery of the cervical spine should perform this method of instrumentation.

Biomechanical Phenomena↗
PubMed1998

Postlaminectomy kyphosis.

Postlaminectomy kyphosis is a rare but potentially catastrophic complication of laminectomy performed to treat cervical myelopathy. The best strategy for prevention is awareness of the sagittal plane before surgery in patients with cervical spondylotic myelopathy. An understanding of the biomechanical forces placed on the cervical spine, the normal structures contributing to stability and the underlying pathologic process helps in the prevention and ultimate treatment of postlaminectomy kyphosis. This is a review of the risk factors, biomechanics, work-up, and surgical treatment of postlaminectomy kyphosis.

Cervical Vertebrae↗
PubMed1998

Anterior junctional plate in the cervical spine.

STUDY DESIGN: This study introduces a useful plating technique for complex reconstructions of the anterior cervical spine. OBJECTIVE: To provide a short-segment-buttressing technique for the stabilization of long anterior fusion constructs in the cervical spine while avoiding the potential morbidity and risks associated with long-segment anterior cervical plating. SUMMARY OF BACKGROUND DATA: Anterior fibular or iliac crest strut grafts are at risk of dislodging when used after multisegment (> 3 vertebrae) corpectomy in various spinal disorders. Long-segment anterior cervical plates have been used to reduce the incidence of graft displacement and migration but have been shown to increase risk for early failure because of screw dislodgement. METHODS: Eleven patients with cervical myelopathy underwent a multilevel (average 3.36 levels) corpectomy followed by the placement of a fibular or iliac crest strut graft. An anterior short-segment locking or buttress plate was then placed in the vertebral body, either inferior or superior to the seated graft, depending on the ease of insertion and quality of the host bone. Posterior segmental fixation was performed in all patients during the same procedure. The average follow-up was 30.8 months (range, 25-36 months). RESULTS: No incidence of plate or graft migration (anteroposterior plane) or dislodgement was reported in this series. One graft fracture occurred secondary to the placement of a intragraft screw through an anterior junctional plate. No patients experienced clinical morbidity related to the junctional plate. Neurovascular complications and wound complications were not encountered in any of these patients. All had an improvement in their neurologic symptoms, and 10 of the 11 patients had fusion documented on plain radiographs. CONCLUSIONS: The use of a junctional plate anteriorly along with posterior segmental fixation and fusion may prevent or decrease the incidence of graft and internal fixation dislodgement after a long-segment cervical reconstruction procedure.

Bone Plates↗
PubMed1998

Use of cervicothoracic junction pedicle screws for reconstruction of complex cervical spine pathology.

STUDY DESIGN: A retrospective review of 21 patients in which cervical pedicle screw fixation was used at C7 with or without upper thoracic pedicle screw fixation. OBJECTIVE: To evaluate the use of pedicle screw placement in the lower cervical spine. SUMMARY OF BACKGROUND DATA: The use of posterior cervical spine fixation, including lateral mass fixation, has become increasingly popular in recent years. However, lateral mass fixation at C7 is often hindered by lack of substantial high quality bone. The end level of long cervical spine constructs is frequently C7 or T1. Dissatisfaction with lateral mass fixation at C7 and T1 led the authors to use lower cervical pedicle screw fixation for several cervical spine disorders. METHODS: Twenty-one patients who had undergone cervical pedicle screw fixation at C7 were reviewed retrospectively. There were 12 males and 9 females, with an average age of 52 years. All pedicle screws were placed, after direct palpation of the pedicle, with a right angle nerve hook after laminoforaminotomy at C7. RESULTS: There were no neurologic complications related to pedicle screw placement, and no patient was symptomatically worse after the operation. Six patients with root pathology improved. Of 14 patients with cervical myelopathy, 12 improved at least one Nurick grade, and 2 had no improvement. There were no failures of fixation or complications related to pedicle fixation at a minimum of 1 year follow-up. CONCLUSION: Pedicle screws in C7 placed with laminoforaminotomy and palpation technique appears to be safe and efficacious. Excellent fixation can be achieved.

Bone Screws↗
PubMed1998

Variation in surgical opinion regarding management of selected cervical spine injuries. A preliminary study.

STUDY DESIGN: The opinions of orthopedic surgeons and neurosurgeons were compared regarding appropriate management of selected cervical injuries and the timing of stabilization. OBJECTIVE: To determine whether there is consistency of opinion regarding the management of cervical trauma. SUMMARY OF BACKGROUND DATA: Numerous forms of management for cervical trauma exist, but there are few consistent recommendations. No previous study has been done to determine uniformity of preferences of the surgeons who manage these injuries. METHODS: Thirty-one orthopedic surgeons and neurosurgeons were given a brief clinical situation and pertinent radiographic studies of five selected cervical injuries. Management options included halo and nonhalo orthoses, traction, and various forms of anterior and/or posterior procedures. The surgeons rated, in whole numbers from 1 to 10, their opinions on the appropriateness of each technique. Each surgeon was given a case of a "generic" cervical injury, in which stabilization was required and for which preoperative alignment was adequate in traction. They gave opinions on the timing of stabilization, with a choice of four time frames. Four neurologic situations were rated, ranging from intact to complete cord injury. RESULTS: Of 46 possible responses to the five test cases regarding appropriateness, 18 ranged from 1 to 10, the largest possible variation. Only 2 had a range of 5 or less, implying better consensus among tested surgeons. Mean values ranged from 1.9 to 9.5. Agreementamong respondents regarding appropriateness was slight with a range of kappa statistics from 0.09 to 0.14. Of 16 possible responses regarding timing, 14 were within a range of 8 or higher. Within 24 to 72 hours was the generally preferred time frame, with all possible responses showing a range of 3 or 4. Results of a multiple analysis of variance showed no significant differences among respondents. CONCLUSION: There is a large variety of opinion regarding appropriateness of specific operative and nonoperative management procedures and surgical timing among the surgeons polled who manage cervical trauma. This implies that there is no widely accepted standard management procedure for many of these injuries.

Adolescent↗
PubMed1998

Long-term evaluation of vertebral artery injuries following cervical spine trauma using magnetic resonance angiography.

STUDY DESIGN: A prospective study to determine the long-term outcome of traumatically induced vertebral artery injuries. Magnetic resonance angiography was performed at the time of cervical injury and at a follow-up office visit. OBJECTIVE: To determine the long-term outcome in terms of arterial flow competency of traumatically induced vertebral artery injuries. SUMMARY OF BACKGROUND DATA: Vertebral artery injury associated with cervical spine trauma has been well documented; however its healing or nonhealing potential has not been elucidated. METHODS: During the 7-month period from July 1993 to January 1994, all patients admitted to the authors' institution with cervical spine injuries underwent magnetic resonance imaging and magnetic resonance angiography of the cervical spine to determine the patency of their vertebral arteries. Magnetic resonance angiography was performed at the time of injury and at a follow-up office visit. Twelve of 61 patients were found to have a lack of signal flow within one of their vertebral vessels during this study period. RESULTS: Eighty-three percent of the patients (five of six) who were available for follow-up observation in this study did not manifest flow reconstitution of their vertebral arteries after an average 25.8-month follow-up period. CONCLUSIONS: According to these data, most patients with vertebral artery injuries after nonpenetrating cervical spine trauma do not reconstitute flow in the injured vertebral arteries. This lack of flow must be considered if future surgery in this region of the cervical spine is contemplated.

Adult↗
PubMed1998

Magnetic resonance imaging analysis of lumbar disc changes below scoliosis fusions. A prospective study.

STUDY DESIGN: The authors of this prospective study examined the preoperative and 3-year postoperative magnetic resonance images of 14 patients undergoing anterior and posterior fusion and/or posterior fusion only for scoliosis. All magnetic resonance images were ready by two independent neuroradiologists, who were blinded to the purposes of the study, for the presence of disc narrowing, signal decrease on T2, or herniated nucleus pulposus before and after surgery. Particular attention was paid to the disc changes at the level directly below the end vertebral level of the fusion and two levels below the fusion in the lumbosacral spine existing before surgical intervention. OBJECTIVES: To evaluate the potential for disc degeneration distal to long scoliosis fusions with end fusion levels in the mid to lower lumbar spine. SUMMARY OF BACKGROUND DATA: The determination of end levels of fusion for contructs presently used to manage adult scoliotic deformity has been evaluated in terms of correction of curvature and late decompensation in coronal and sagittal plane balance after fusion. However, the natural history of the caudal, free-motion segments in terms of degeneration and/or correlation with pain has not yet been addressed. METHODS: Fourteen patients undergoing scoliosis fusion underwent magnetic resonance imaging before surgery and approximately 3 years after surgery. The scans were reviewed by two independent neuroradiologists who looked at three degenerative indices at the disc below the area of scoliosis fusion. The authors analyzed rates of change of the three degenerative indices in the pre- and postoperative magnetic resonance images and created associations between the observed changes on the magnetic resonance images and the clinical outcomes of pain, the presence or absence of solid fusion, and the need for repeat surgery. RESULTS: Estimates of the rates of change of the three degenerative indices one or two levels below the fusion were as follow: the chance of disc narrowing, .2-34%; the chance of a decreasing signal on T2, 5-54%, with a 23% incidence among this group; and the chance of herniated nucleus pulposus, 0-34%. There was a significant correlation between the presence of back and/or leg pain and the signal decrease one level below the fusion (P = .04). CONCLUSIONS: If these results are corroborated in a larger sample size, surgeons who manage deformity may have to consider altering fusion levels at the time of fusion based on magnetic resonance imaging predictors. The present data may help to inform patients about the risk of developing junctional degenerative changes and potential symptoms from these changes below scoliosis fusions.

Adolescent↗
PubMed1998

The benefits of early decompression in cervical spinal cord injury.

Decompression and stabilization have been shown to improve neurologic outcome in cases of cervical spine trauma with proven compression of the spinal cord. This paper reviews experimental and clinical research to clarify the benefits of early surgery for cervical spinal cord injury. The direct clinical benefit of early surgery is a theoretic improvement in neurologic recovery over that of delayed surgery. Additional benefits of early surgery include the clinical advantages of a decreased length of hospitalization and its associated complications and a decreased time to rehabilitation and mobilization. Proper, timely surgical intervention can better the physiologic environment so as to allow for maximum neurologic improvement.

Animals↗
PubMed1998

Neurologic deterioration after cervical spinal cord injury.

Neurologic deterioration after cervical spinal cord injury (SCI) at a regional spinal cord center was examined. This study examined the incidence of neurologic deterioration as well as associated risk factors in our patient population. Up to 5.8% of cervical SCI patients have been noted to deteriorate neurologically after admission. Risk factors have been early surgery, halo application, traction, and Stryker frame rotation. All cervical SCI patients admitted between 1978 and 1993 who had neurologic deterioration were studied for characteristics of their event, operative status, risk factors, mortality, and neurologic return at 1 year postinjury. Patients were divided into minor and major groups based on the degree of neurologic loss. Nineteen of 1,031 patients were identified as neurologically deteriorated (1.84%). There were 8 major and 11 minor group patients. The average time from injury to deterioration was 3.95 days. Of 10 patients undergoing surgery at < or =5 days, 8 deteriorated postoperatively. Potential risk factors were ankylosing spondylitis (three patients), sepsis (four patients), and intubation (four patients). Neurologic recovery at 1 year showed that 11 of 12 patients were improved. Neurologic deterioration occurred in 1.84% of our patients. Deteriorations were associated with surgery at <5 days after injury, ankylosing spondylitis, sepsis, and intubation.

Adult↗
PubMed1998

Accuracy of SPECT scanning in diagnosing pseudoarthrosis: a prospective study.

The present study attempted to analyze the efficacy of single photon emission computed tomography (SPECT) in diagnosing pseudoarthrosis after fusion using surgical exploration as the gold standard. This study examined the SPECT scans of 38 patients before they underwent surgical exploration of their fusion mass for suspected pseudoarthrosis or in conjunction with instrumentation removal. Surgical findings were compared with the radiologists' findings to determine the efficacy of SPECT in diagnosing pseudoarthrosis. Radiographic determination of pseudoarthrosis has been difficult after attempted fusion of the spine. Multiple radiographic modalities have been touted as accurate depicters of the failure of spinal fusion. However, no method has been found to be highly accurate in the clinical setting. Thirty-eight patients (mean age = 42.8, 21 males/17 females, 35 of 38 with instrumentation) underwent SPECT scans before surgical exploration of their fusion mass for suspected pseudoarthrosis or in conjunction with instrumentation removal as part of this prospective study. The average interval from their fusion procedure until their SPECT scan was 23.9 months (range, 9-120 months). All surgical findings were recorded with regard to solidity of the fusion and the level of the possible pseudoarthrosis. All SPECT scans were read at a time after surgery by an independent nuclear radiologist who had not read their SPECT scans before surgery and who did not know the results of exploration. Results of the radiologist's reading were then compared with surgical exploration findings, and sensitivity and specificity was calculated. There were 24 solid fusions and 14 pseudoarthroses. SPECT scans correctly identified 7 of the 14 pseudoarthroses and 14 of the 24 solid fusions. This represents a sensitivity of 0.50 and a specificity of 0.58. SPECT scanning correctly diagnosed the one solid fusion and two pseudoarthrosis patients in the three patients who had no instrumentation. This study demonstrates that SPECT scanning alone is inaccurate in diagnosing pseudoarthrosis when using surgical exploration as the gold standard. Given recent pressures for cost containment, we cannot recommend SPECT scanning as a routine modality for use in the diagnosis of pseudoarthrosis. We cannot define the accuracy of SPECT scanning used together with computed tomography scans, plain films, or other radiographic modalities in the diagnosis of pseudoarthrosis.

Adult↗
PubMed1998

Foraminal pressure changes during intervertebral distraction simulating anterior cervical discectomy.

Distraction of the disc space over baseline height has been shown to increase foraminal size. The purpose of this procedure is to determine pressure changes, with disc space distraction simulating an anterior cervical discectomy and fusion (ACDF). An analysis of pressure changes during disc space distraction at C5-C6 was performed. Data were analyzed for maximal pressure observed and for pressure change with prolonged distraction. Five cadaveric specimens underwent a discectomy at the C5-C6 level. Distraction of the disc space was performed and pressure measurements were obtained from within the foramen. Measurements were made for maximal pressure with an intact posterior longitudinal ligament (PLL), divided PLL, and with the nerve root removed from within the foramen. Pressures were also recorded with prolonged distraction until a steady state was achieved. Incremental distraction of +2, +4, and +6 mm resulted in pressure increases within the foramen. Sectioning of the PLL did not affect these increases. Removal of the nerve root from the foramen resulted in pressure increases; however, these were not significantly different from baseline. Prolonged distraction produced an initial increase and a gradual return toward baseline. Final pressures still differed significantly from baseline. Increase intraforaminal pressures can be seen with increasing disc space distraction such as occurs during an ACDF. This suggests that either the foramen narrows in at least one dimension and/or soft-tissue attachments to the nerve produce a tensile force in the nerve as they tighten. The pressure increases relax over time.

Aged↗
PubMed1998

The changing nature of admissions to a spinal cord injury center: violence on the rise.

The purpose of this study was to analyze changing etiologies for admission to a spinal cord injury center. This study was designed to retrospectively analyze the etiology of admissions to a spinal cord injury center during a 15-year period, specifically gunshot versus nongunshot wound injuries. Gunshot wounds are a well-recognized cause of spinal cord injury. In some centers, up to 52% of admissions are due to this, and these trends are believed to be increasing. All patients with spinal cord injury admitted to our center between 1979 and 1993 were analyzed. Frequencies of specific etiologies were determined and then comparisons were made between gunshot wound and nongunshot wound groups. Factors analyzed included age, male/female ratio, ethnic make-up, marital status, employment status, level of injury, and neurologic status. One thousand eight hundred seventeen patients were included. Overall, gunshot wound spinal cord injuries compromised 16.9% of injuries. A clear trend of increasing numbers of admissions was seen between 1984 and 1993 because of this. Gunshot wounds and nongunshot wounds differed dramatically in terms of age, ethnic make-up, marital status, employment status, and neurologic status. Cost attributed to treating gunshot wound injuries at our center for 1993 was 5.4 million dollars. Gunshot wounds as a cause of spinal cord injury are increasing at an alarming rate. The demographics of the gunshot wounds and nongunshot wound spine cord injuries differ significantly.

Accidents, Traffic↗
PubMed1997

Vertebral artery occlusion associated with cervical spine trauma. A prospective analysis.

STUDY DESIGN: Radiographs and charts of 61 patients sustaining cervical spine trauma were studied prospectively to determine the incidence of vertebral artery injuries and possible correlative factors. Statistical analysis was conducted using chi-square testing of a two-way classification system. OBJECTIVES: To elucidate the incidence of vertebral artery injuries associated with cervical spine trauma, and to determine the value of various factors in predicting the existence of a vertebral artery injury. SUMMARY OF BACKGROUND DATA: During a 7-month period, 61 patients (41 male patients, 20 female; average age, 40.3 years) with cervical spine trauma were studied. METHODS: All patients admitted to the authors' hospital with cervical spine injuries underwent magnetic resonance imaging and magnetic resonance angiography of their cervical spine. All magnetic resonance angiographies were examined for vertebral artery injury. Data on demographics and the injury were recorded. RESULTS: Complete disruption of blood flow through the vertebral artery was demonstrated by magnetic resonance angiography in 12 of the 61 patients (19.7%). Ten of the 12 patients (83%) had either flexion distraction or flexion compression injuries. Age, sex, mechanism of injury, neurologic impairment, and associated injuries were not statistically significant in predicting the presence of a vertebral vessel occlusion. CONCLUSION: The findings in this study may support the need for vertebral vessel evaluation in selective patients, particularly those with flexion injuries and with neurologic symptoms consistent with vertebral artery insufficiency syndrome that do not correlate with the presenting bone and soft-tissue injuries.

Adolescent↗
PubMed1997

Steroids and gunshot wounds to the spine.

OBJECTIVE: The second National Acute Spinal Cord Injury Study demonstrated that there were neurological benefits from "spinal cord injury" doses of methylprednisolone for blunt spinal cord injuries. In this review, we examined the relative risk/benefit ratio of intravenously treating spinal gunshot wound victims with steroids. METHODS: A retrospective review was conducted of 254 consecutive patients who were treated between 1979 and 1994 for gunshot wounds to the spine (C1-L1) and a spinal cord injury. Three subgroups were established based on the administration of the steroids methylprednisolone (National Acute Spinal Cord Injury Study 2 protocol), dexamethasone (initial dose, 10-100 mg), and no steroids. All patients who received steroids were initially treated at another hospital and then transferred. No patients received steroids at our institution. The data analyzed included neurological outcome and infectious and noninfectious complications. RESULTS: No statistically significant neurological benefits were demonstrable from the use of steroids (methylprednisolone, dexamethasone). Infectious complications were increased in both groups receiving steroids (not statistically significant). Gastrointestinal complications were significantly increased in the dexamethasone group (P = 0.021), and pancreatitis was significantly increased in the methylprednisolone group (P = 0.040). The mean duration of follow-up was 56.3 months. CONCLUSION: In this retrospective, nonrandomized review, no neurological benefits were detectable from intravenously administered steroids after a gunshot wound to the spine. Both infectious and noninfectious complication rates were higher in the groups receiving steroids. Patients who sustain a spinal cord injury secondary to a gunshot wound to the spine should not be treated with steroids until the efficacy of such treatment is proven in a controlled study.

Adolescent↗
PubMed1997

An in vivo analysis of the dimensional changes of the neuroforamen after anterior cervical diskectomy and fusion: a radiologic investigation.

Eighteen patients (11 men, 7 women; average age, 45.5 years) who underwent anterior cervical diskectomy and fusion (ACDF) for the treatment of radiculopathy had preoperative and immediate postoperative computed tomography (CT) scans to measure pre- and postoperative foraminal heights and foraminal areas, preoperative disk space height, and postoperative graft height. The mean foraminal height preoperatively was 0.851 cm; postoperatively, it was 1.01 cm, with a mean percentage increase of 20% (-8.8 to 56.8%). Mean preoperative foraminal area was 37.53 mm2, increasing to a mean of 49.04 mm2 postoperatively with a mean percentage increase of 33% (range, -1.5 to 76.9%). No significant correlations between graft height and change in maximal foraminal height or foraminal area or between changes in foraminal height or area and postoperative symptom relief were found. Although significant increases in foraminal dimensions were seen radiographically after ACDF, these increases were variable and not strongly related to graft height. In addition, the increases in foraminal dimensions were not related to the short-term clinical results of ACDF. This study fails to support the hypothesis that the reliable results of ACDF can be ascribed primarily to indirect decompression of the uncovertebral foramen by disk-space distraction.

Adult↗