RESUMEN

The purpose of this study was to further establish the efficacy of pedicle screw stimulation as a monitoring technique to avoid nerve root injury during screw placement. The study population consisted of 662 patients in whom 3,409 pedicle screws were placed and tested by electrical stimulation. If stimulation resulted in a myogenic response at a stimulation intensity of 10 mA or less, the placement of the screw was inspected. Inspection was necessary for 3.9% of the screw placements in 15.4% of the study population. None of the patients in the study experienced any new postoperative neurologic deficits. These findings provide guidelines for the interpretation of stimulation data and support the use of this technique as an easy, inexpensive, and quick method to reliably assess screw placements and protecting neurological function.

Asunto(s)

RESUMEN

STUDY DESIGN: Fifty-one consecutive patients who underwent extradural sensory rhizotomy for chronic radiculopathy after lumbar surgery were reviewed retrospectively. OBJECTIVES: To determine the effectiveness of sensory rhizotomy in the management of chronic radiculopathy in patients selected by extensive imaging techniques and selective nerve root sheath injections. SUMMARY OF BACKGROUND DATA: Results of more central ablative procedures for chronic benign pain problems have been disappointing, with variable reports of pain relief. METHODS: Fifty-one patients were reviewed. All patients underwent extensive evaluation to exclude reversible structural lesions, and all had the diagnosis of chronic radiculopathy confirmed by results of clinical and electrophysiologic examination. Selective nerve root sheath injections under fluoroscopic guidance confirmed the symptomatic nature of the segments. All blocks were repeated at least once. All patients underwent selective sensory rhizotomy or, in some cases, complete rhizotomy. After rhizotomy, 37 patients were available to be observed at selected time intervals for a minimum of 2 years. Clinical results were determined by the presence or absence of pain relief (visual analog scale), sensory and motor deficits, narcotic analgesic usage, and the patient's estimation of the effectiveness of the procedure. RESULTS: At 6 months after surgery, all 51 patients and the outcomes of their surgery were available for review. Fifty-five percent of patients rated were believed to have good or excellent outcomes, whereas the remainder had poor or failed outcomes. For the minimum 2-year follow-up period (range, 2-4.2 years), 37 patients were available for review. At final follow-up examination only 19% of the patients maintained good or excellent outcomes. CONCLUSIONS: The results of the rhizotomy procedures deteriorated over time. Possible reasons for the failure, other than temporal deterioration, were anatomic factors and lack of specificity of diagnostic techniques, specifically selective nerve root sheath injection. At this point rhizotomy cannot be recommended with any confidence whatsoever in the setting of chronic lumbar radiculopathy after lumbar surgery.

Asunto(s)

RESUMEN

STUDY DESIGN: Patients who had lumbar spine surgeries and experienced residual symptoms were prospectively studied using computed tomography/discography and enhanced magnetic resonance imaging. OBJECTIVES: Determining the sensitivity and specificity of gadolinium-enhanced magnetic resonance imaging versus computed tomography/discography in distinguishing scarring from recurrent disc herniation was the first objective. The second goal was to determine if there were any imaging characteristics unique to either scar or recurrent disc herniation. SUMMARY OF BACKGROUND DATA: The results of reoperation for recurrent disc herniation are uniformly good, whereas the results of reoperation for scar tissue are poor. There have been no studies comparing the ability of enhanced magnetic resonance imaging and computed tomography/discography to distinguish between scar and herniation material. METHODS: Two neuroradiologists who were blinded to the surgical findings in 33 patients independently reviewed the imaging studies and labeled abnormalities as disc herniation or scar tissue. Their responses were compared with surgical findings to determine the accuracy, sensitivity, and specificity of each test. Also, imaging studies were used to determine if disc material or scar tissue had specific imaging characteristics. RESULTS: Computed tomography/discography was more sensitive and specific in distinguishing between scar tissue and recurrent disc herniation. Information from both studies improved the sensitivity over either test alone. Characteristics associated with recurrent disc herniation included nonenhanced or rim-enhanced abnormality surrounding a low signal intensity lesion on magnetic resonance imaging and extension of contrast into the epidural space and an enhancing abnormality on computed tomography/discography. CONCLUSIONS: Using computed tomography/discography alone or with enhanced magnetic resonance imaging enables surgeons to distinguish between scarring and recurrent disc herniation so they can determine the need to re-enter the spinal canal.

Asunto(s)

RESUMEN

Forty-five patients who had residual symptoms after lumbar spine surgery were re-evaluated and underwent additional surgery. After a minimum of 2 years' follow-up, these patients' results were reviewed to determine what variables might predict long-term outcome. Age, number of previous operations, and psychological diagnosis were not statistically significant, but a non-compensable injury, ability to return to work after surgery, a negative history of litigation, and achieving a solid fusion were statistically significant in predicting a good outcome. In this study of 45 patients who had repeat surgery, 82% were improved at an average follow-up of 28.2 months. Intrathecally enhanced computed tomography, magnetic resonance imaging, discography, and computed tomography-discography are required to thoroughly evaluate the previously operated lumbar spine, because a single imaging study showed surgical abnormalities in only 61% of the patients in this study.

Asunto(s)

RESUMEN

Intraoperative technical complications of pedicle screw fixation include screw cutout or maldirection and pedicle fracture. The aims of this study were 1) to use computed tomography to determine the average pedicle diameter; and 2) to compare these measurements with the outer diameter measurements of commonly used pedicle screws. The pedicle diameters of L2, L3, L4, L5, and S1 were measured in 154 adult patients (81 men, 73 women) who had low-back pain. The distance across the isthmus of the pedicle was measured with the distance mode on the axial computed tomographic image in the bone window setting. The lateral computed tomographic scout view was used to select the axial section through the midportion of the pedicle. To standardize data retrieval, the lower four motion segments were denoted as L2-S1, even when there were more or fewer than five lumbar vertebrae. The pedicle diameter at each level was measured and averaged for all patients and for men and women separately. The percentage of pedicles that measured less than 7 mm was determined at each level. The average pedicle diameters were 8.13 mm for L2, 8.7 mm for L3, 10.88 mm for L4, 14.54 mm for L5, and 18.37 mm for S1. Twenty percent of the L2 pedicle diameters, 15.6% of L3, and 1.9% of L4 were less than 7 mm; none of the L5 or S1 pedicles measured less than 7 mm. The outer diameters of the most commonly used pedicle screws range from 5 mm to 7 mm. Screw pitch, tooth profile, outer diameter, and depth of penetration affect implant strength.(ABSTRACT TRUNCATED AT 250 WORDS)

Asunto(s)

RESUMEN

Two hundred fifty patients with low-back pain who underwent lumbar discography followed by computed tomography (CT) are the subject of this prospective study. In 93% of the patients, these combined imaging techniques provided additional useful diagnostic information that affected patient management and the selection of treatment alternatives. Lumbar discography followed by CT proved valuable in determining the significance of equivocal or multiple level abnormalities, determining the type of disc herniation, defining surgical options, and evaluating the previously operated spine. In 94% of patients who had surgery, CT-discography correctly predicted the type of disc herniation as protruded, extruded, sequestrated, or internally disrupted. Computed tomography-discography may be more sensitive that magnetic resonance imaging (MRI) in the early stages of disc degeneration because 18 of 177 discs with a normal T2-weighted image were discographically abnormal and the CT-discogram revealed annular tears or radial fissuring. The radiographic morphology of the normal herniated and degenerative lumbar discs shown by CT-discography gives unique insight into the pathogenesis of disc degeneration. The complications that followed the 750 discograms were one case of urticaria and one disc space infection. Even with the availability of high resolution CT and MRI, lumbar discography remains the only pain provocation challenge to the lumbar disc.

Asunto(s)

RESUMEN

Operative treatment for cervical spondylotic myelopathy and myeloradiculopathy by anterior decompression produced functional improvement of one grade (Nurick's rating system) in 16 of 21 patients evaluated at 32 months average follow-up period. The best results occurred in patients with symptoms for less than one year and classified as grades I-III. The anterior approach for decompression is preferred because it is directed toward the degenerative structures responsible for cord and root compression. The autogeneic fibula dove-tailed strut graft is favored over an iliac crest bone graft because with multilevel decompression in the cervical spine, it provided structural stability and a high union rate. There were no neurologic complications in this series of 21 cases.

Asunto(s)

RESUMEN

A retrospective review of 1293 cases of low back pain treated over a 12-year period revealed that sacroiliac joint syndrome and posterior joint syndromes were the most common referred-pain syndromes, whereas herniated nucleus pulposus and lateral spinal stenosis were the most common nerve root compression lesions. Referred pain syndromes occur nearly twice as often and frequently mimic the clinical presentation of nerve root compression syndromes. Combined lesions occurred in 33.5% of cases. Lateral spinal stenosis and herniated nucleus pulposus coexisted in 17.7%. In 30% of the cases of spondylolisthesis, the radiographic findings were incidental and the source of pain was the sacroiliac joint. Distinguishing radicular from referred pain, recognition of coexisting lesions, and correlation of diagnostic imaging with the overall clinical presentation facilities formulation of a rational plan of therapy. The above-outlined approach to managing low back pain evolved over a 12-year period. Designed to establish a specific diagnosis, it should yield excellent or good results in 84% of patients.

Asunto(s)

Asunto(s)

RESUMEN

Forty-two cases of congenital scoliosis, four cases of congenital kyphosis and one case of congenital lordosis were reviewed retrospectively from 1975 through 1982, with an average follow-up of 5.09 years. Associated anomalies occurred in 62.5% of the cases, with Sprengel's deformity and Klippel-Feil syndrome being the most common musculoskeletal anomalies. The rate of abnormal intravenous pyelography was 21.8%, and absent kidneys or duplication of collecting systems accounted for the majority of renal abnormalities. Myelographic abnormalities were noted in eight of twenty-five studies and included two cases of diastematomyelia and one tethered cord syndrome. Initial treatment was observation (11), bracing (11), and surgery in the remaining 25 cases. The surgical complication rate was 22.8%. Progressive deformities led to additional surgical procedures in six cases which had previous in situ fusions.

Asunto(s)

Asunto(s)

RESUMEN

Eleven cases of fracture of the thoracic and lumbar spine were treated with segmental spinal instrumentation (Luque rods). The majority of these injuries occurred in motor vehicular accidents or falls from a height and were usually associated with multisystem trauma. This method of instrumentation provided immediate rigid internal fixation, which obviated the need for postoperative orthoses, allowed easier nursing care and early ambulation, and facilitated rehabilitation of patients with spinal cord injury. At 13 months' average follow-up, there have been no instances of wire breakage, rod deformation, or deterioration of neurologic status. This favorable experience suggests that segmental spinal instrumentation should be considered as an alternative mode of spinal instrumentation in fractures of the thoracic and lumbar spine.

Asunto(s)

RESUMEN

Acromioclavicular (AC) dislocation with a concomitant coracoid process fracture occurs infrequently. This fracture should be suspected with all AC dislocations occurring in the first three decades of life. An axillary lateral radiograph or tomogram often is needed to detect the fracture. Surgical treatment can produce good results, but equally satisfactory function with minimal residual cosmetic deformity may be achieved by nonsurgical measures.

Asunto(s)

Asunto(s)