James W. Simmons

The prolapsed intervertebral disc : The high-intensity zone with discography correlation

Study Design The study compared the presence of the high‐intensity zone on magnetic resonance imaging with the results of awake discography. Objectives To see if there was a correlation between the results of awake discography and the presence of a high‐intensity zone on magnetic resonance imaging. Summary of Background Data The evaluation of discogenic pain has proved to be somewhat elusive. Recent studies have indicated the high‐intensity zone as being highly sensitive in the diagnosis of the painful discogenic segment. The present study was designed to investigate whether the presence of a high‐intensity zone is associated with a concordant pain response on awake discography. Methods Magnetic resonance images were obtained in 29 patients with low back pain with and without radiculopathy. Consecutive patients were considered for surgical intervention after failing to respond to conservative treatment. The presence of a high‐intensity zone was specifically looked for within the posterior anulus. Each patient subsequently underwent awake discography with computed tomography. Computed tomography was classified according to the Dallas Discogram Scale and the presence of a concordant pain response. Chi‐square analysis was used to calculate the presence of a high‐intensity zone versus disc disruption and the correlation of high‐intensity zone and concordant pain response. Results There was no statistically significant correlation between the presence of a high‐intensity zone and a concordant pain response at any level. The high‐intensity zone was, however, never seen in a morphologically normal disc. Conclusions Although the high‐intensity zone is present within the posterior anulus of some abnormal discs, it is not necessarily associated with a concordant pain response.

Intradiscal steroids: A prospective double-blind clinical trial

A prospective, randomized, double-blind study was performed to evaluate the clinical efficacy of intradiscal steroid injections. Criteria for entrance were one-level internal disc disruption or nonsequestered nuclear prolapse with or without sciatica and a positive pain response on awake discography. Exclusion criteria were multilevel disease, central or lateral stenosis, prior lumbar surgery, or medical disease requiring systemic steroids. A total of 25 patients were randomly assigned to Treatment Group A (methylprodnisolone, Depo-Medrol 80 mg/ml, The Upjohn Co., Kalamazoo, Michigan) or Treatment Group B (bupivacaine, Marcaine .5% 1.5 ml, Sanofi Winthrop Pharmaceuticals, New York, New York). Fourteen patients received Depo-Medrol, with 21% showing subjective improvement and 79% no improvement; 0% were clinically worse. Eleven patients received intradiscal Marcaine, with 9% showing clinical improvement and 91% no improvement; 0% were clinically worse. To quantify clinical response, a pain diagram grid score, a visual analog scale, and the Oswestry Pain Questionnaire were used before injection and 10–14 days after injection. No statistically significant benefit was identified in the use of intradiscal steroids.

Posterior lumbar interbody fusion with posterior elements as chip grafts

The advantages of posterior lumbar interbody fusion (PLIF) have been enumerated over the past 40 years. A surgical technique of PLIF, with use of posterior elements cut into small corticocancellous chips measuring 2-4 mm as graft material, has distinct advantages. The PLIF technique with autogenous chip grafts on 113 patients treated between 1974 and 1980 produced as high as 79% objectively good results.

Determining successful pain clinic treatment through validation of cost effectiveness.

Initially, the Center for Pain Control designed and implemented multiple measures to indicate treatment efficacy in an outpatient setting. Decreased use of medical care at 1 year after treatment was one of five measures used. Economic concerns, both in the health and the insurance industries, mandated greater emphasis on cost effectiveness at a primary success determinate. Cost effectiveness was measured through broad diagnostic categories: lumbar pain with or without radiculopathy, cervical pain with and without radiculopathy, and a combination of lumbar and cervical pain. Cost for surgical treatment was determined using community-based charges. This cost was compared to actual cost incurred by outpatient pain treatment together with 6 months aftercare. Significant savings is indicated by the above cost comparison.

Correlation of bone equivalent mineral density to pull-out resistance of triangulated pedicle screw construct

Thirty single-pedicle and triangulated pedicle screws were subjected to pull-out tests until complete dislodgment was achieved. Peak load, displacement curves, angle of triangulation, and equivalent mineral density were recorded. Dual pedicle screw triangulation produced a 154.4% increase in peak pull-out strength compared with that of the single pedicle screw. Salvage triangulation (replacing failed screws with a triangulation construct) produced a 127.4% increase in peak strength over that of the single screw. Positive correlation was found between individual screw peak strength, bone mineral density, and displacement at peak load. Primary and salvage triangulation produced higher resistance to pull-out than a single pedicle screw, which reflects the potential, beneficial effect of using this technique. Triangulation, therefore, can be used as primary (prophylactic) technique to enhance pedicular screw pull-out during forceful vertebral manipulation.

The effect of mid-thoracic VEPTR opening wedge thoracostomy on cervical tilt associated with congenital thoracic scoliosis in patients with thoracic insufficiency syndrome

Study Design. Prospective clinical trial of vertical expandable prosthetic titanium rib (VEPTR) surgery in patients with congenital thoracic scoliosis with thoracic insufficiency syndrome and cervical tilt. Objective. Report efficacy and safety of VEPTR mid-thoracic opening wedge thoracostomy in treatment of cervical tilt and head/truncal decompensation in children with thoracic insufficiency syndrome associated with thoracic congenital scoliosis. Summary of Background Data. Cervical tilt in children is a rare problem, usually associated with congenital cervical or cervical-thoracic scoliosis, and in progressive deformity, surgical fusion or hemi-vertebrectomy risks neurologic injury, loss of motion of the cervical spine, and unknown effect on pulmonary function. VEPTR patients with congenital scoliosis can have severe neck tilt with poor cosmesis, with the risk of neck pain in adulthood. VEPTR mid-thoracic opening wedge thoracostomy treats thoracic insufficiency syndrome, and paradoxically also appears to improve the neck alignment cosmesis. Materials Methods. Patients with fused ribs and congenital scoliosis, thoracic insufficiency syndrome, and cervical tilt were treated with VEPTR mid-thoracic thoracostomy. Complication rates, respiratory outcome, pulmonary function tests in older children, Cobb angles, head/truncal decompensation, T1 oblique take-off, space available for lung, height of the thoracic spine, and cervical tilt angle were measured. Results. Fourteen patients with cervical tilt, fused ribs, progressive congenital scoliosis, and TIS were treated. The primary thoracic scoliosis and space available for lung improved, cervical tilt stabilized, and head and truncal decompensation improved. One child was weaned off a ventilator. Complications included device migration, infection, and transient brachial palsy. Conclusion. Mid-thoracic VEPTR opening wedge thoracostomy can stabilize cervical tilt associated with thoracic congenital scoliosis and fused ribs and may be an alternative to cervicothoracic spine fusion or hemi-vertebrectomy in some young children.

Plaster of Paris as an Osteoconductive Material for Interbody Vertebral Fusion in Mature Sheep

Study Design. In adult female sheep, histologic and biomechanical criteria were used to determine whether the osteoconductive performance of plaster of paris would promote the incorporation of the tubular titanium mesh implants used for interbody vertebral fusions. Objectives. To compare the osteogenicity of plaster of paris with that of autogenous iliac crest bone and bone marrow 6 months after they were loaded into tubular titanium mesh cages and implanted as L3–L5 bridges after L4 corpectomies. Summary of Background Data. One of the aims of surgery for vertebral pathology is to stabilize the spine by interbody fusions. The morbidity associated with the use of iliac crest autograft bone for fusion grafts prompted trials using plaster of paris as an osteoconductive substrate. Methods. The total volume of bone that invested the L3–L5 mesh cages after 6 months was quantitated by computed tomography scans. All specimens subsequently were cut into fusion mass segments for biomechanical testing in flexion, extension, compression, and torsion, and then embedded in plastic for sectioning and histomorphometry to determine the trabecular bone volume within the titanium mesh. Results. In each experimental model, implants of plaster of paris were the osteoconductive equal of autogenous iliac crest bone/marrow preparations. The volumes of bone formed around and within the titanium mesh were identical, and the tissues were biomechanically indistinguishable. A partial mechanism was determined by modifying the system for midshaft femoral defects. Conclusions. In the sheep, a tubular titanium mesh packed with plaster of paris forms an osteoconductive conduit to achieve a biomechanically stable interbody lumbar vertebral fusion.

A digitizing technique for the study of movement of intradiscal dye in response to flexion and extension of the lumbar spine

The effects of flexion and extension exercises on lumbar discs and low-back pain are controversial. Our goals were to develop a technique and program for digitizing and analyzing discograms and to study the motion of intradiscal dye in response to flexion and extension. Thirty-five patients following awake discography were evaluated with lateral radiographs obtained in an extension position and a flexion position. Fifty-three segments with normal morphology and 47 segments with abnormal morphology were studied. Discograms with normal morphology showed numerically significant change in position with a more anterior position occurring during extension. Changes in the position of intradiscal dye in discs with abnormal morphology were less predictable. Digitizing was an advantageous technique.

Chemonucleolysis: the state of the art.

Abstract This review presents the history of chemonucleolysis, the techniques, indications, contraindications, and complications. Presenting an historical overview and comparison of success rates with surgical discectomy may provide a fresh understanding of the controversy surrounding chemonucleolysis and establish its efficacy in relation to more invasive treatments. A review of the literature from 1973 through 1998 for chemonucleolysis, open discectomy, and microdiscectomy provided published success rates for these procedures, and a mean rate with standard deviation was determined. In the experience and opinion of the authors, chemonucleolysis remains a viable alternative for patients who have exhausted all conservative means of treatment. Proper patient selection leads to success rates comparable to open discectomy and microdiscectomy.

A 3-D seismic case history evaluating fluvially deposited thin-bed reservoirs in a gas-producing property

We conducted a study at Stratton Field, a large Frio gas-producing property in Kleberg and Nueces Counties in South Texas, to determine how to best integrate geophysics, geology, and reservoir engineering technologies to detect thin-bed compartmented reservoirs in a fluvially deposited reservoir system. This study documents that narrow, meandering, channel-fill reservoirs as thin as 10 ft (3 m) and as narrow as 200 ft (61 m) can be detected with 3-D seismic imaging at depths exceeding 6000 ft (1800 m) if the 3-D data are carefully calibrated using vertical seismic profile (VSP) control. Even though the 3-D seismic images show considerable stratigraphic detail in the interwell spaces and indicate where numerous thin-bed compartment boundaries could exist, the seismic images cannot by themselves specify which stratigraphic features are the flow barriers that create the reservoir compartmentalization. However, when well production histories, reservoir pressure histories, and pressure interference tests are incorporated into the 3-D seismic interpretation, a compartmentalized model of the reservoir system can be constructed that allows improved development drilling and reservoir management to be implemented. This case history illustrates how realistic, thin-bed, compartmented reservoir models result when geologists, engineers, and geophysicists work together to develop a unified model of a stratigraphically complex reservoir system.