Search PubMed⌕ Search

Biomedical subjects

K Gill

Publications and source records attributed to K Gill.

At least 55 records · Page 3Linked to original sources
PubMed1995

Observer variability in the assessment of disc degeneration on magnetic resonance images of the lumbar and thoracic spine.

STUDY DESIGN: Intraobserver and interobserver reproducibility study. OBJECTIVE: This study investigates the variability in the interpretation of degenerative disc findings using magnetic resonance imaging. SUMMARY OF BACKGROUND DATA: Magnetic resonance imaging has been used for years in clinical diagnostics, primarily to investigate disc herniation and spinal stenosis. Less attention has been paid to other disc findings and their assessment reliability. METHODS: Three independent readers evaluated magnetic resonance images of the lumbar and the lower and middle thoracic spines of 122 subjects by grading 12 aspects of the intervertebral discs and adjacent endplates using written definitions and example images. Images of 20 subjects were reevaluated for the assessment of intraobserver agreement. RESULTS: Agreement was highest in the lower lumbar and poorest in the middle thoracic spine. Intraobserver agreement was generally fair to excellent for almost all variables in the lumbar and lower thoracic spine (most intraclass correlation and kappa coefficients for these regions were above 0.70). Interobserver agreement was notably lower than intraobserver agreement, except for osteophytes and endplate defects in some regions. CONCLUSIONS: Intraobserver agreement in the evaluation of disc degeneration was at an acceptable level, in general, in the lumbar and lower thoracic spine. However, assessments were substantially more variable between readers, which limits comparisons of evaluations between different readers.

Adult↗
PubMed1995

Magnetic resonance imaging findings and their relationships in the thoracic and lumbar spine. Insights into the etiopathogenesis of spinal degeneration.

STUDY DESIGN: Descriptive epidemiologic study about magnetic resonance imaging findings in the spine. OBJECTIVES: To describe the prevalence of magnetic resonance imaging findings in a general population at spinal levels T6-S1, and to examine the relationships of these findings within each spinal level and between levels. SUMMARY OF BACKGROUND DATA: The prevalence of specific findings and the associations between findings and spinal levels can provide general insights into the etiopathogenesis of spinal degeneration. METHODS: Subjects consisted of 232 men from a population sample (mean age 49.3 years). Signal intensity, disc bulging, disc herniation, and endplate irregularities were among 11 findings assessed from magnetic resonance images. RESULTS: The disc signal intensities were assessed to be lowest in the lumbar and middle thoracic regions. Disc bulging and disc height narrowing were most common in the lower levels of both the thoracic and lumbar regions. All magnetic resonance imaging findings except herniations and endplate irregularities were clearly associated with age. Osteophytes were most highly associated with disc bulging in levels T6-L3, and with endplate irregularities in the lower lumbar levels. Disc herniations were not consistently associated with any other findings. The disc levels that most highly correlated are grouped as follows: T6-T10, T10-L4, and L4-S1. CONCLUSIONS: With the exception of endplate irregularities and herniations, the magnetic resonance imaging findings appeared to be associated with the same pathogenic process. The interaction of mechanical factors and spinal structures varies between spinal levels, and the degeneration common in the lower parts of the thoracic and lumbar spine could be an outcome of vulnerability for torsional forces. Some gross guidelines for grouping findings can be drawn from disc level correlations.

Adult↗
PubMed1995

The long-term effects of physical loading and exercise lifestyles on back-related symptoms, disability, and spinal pathology among men.

STUDY DESIGN: Historical cohort, including selected subgroups. OBJECTIVES: To understand the long-term effects of exercise on back-related outcomes, back pain, sciatica, back-related hospitalizations, pensions, and magnetic resonance imaging findings were studied among former elite athletes. SUMMARY OF BACKGROUND DATA: Exercise and sports participation have become increasingly popular, as have recommendations of exercises for back problems, but little is known about their long-term effects. METHODS: Questionnaires were returned by 937 former elite athletes and 620 control subjects (83% response rate). Identification codes allowed record linkage to hospital discharge and pension registers. Magnetic resonance images were obtained of selected subgroups with contrasting physical loading patterns. RESULTS: Odds ratios for back pain were lower among athletes than among control subjects, with significant differences in endurance, sprinting and game sports, and wrestling and boxing. No differences in the occurrence of sciatica or in back-related pensions and hospitalizations were seen. When comparing lumbar magnetic resonance images of 24 runners, 26 soccer players, 19 weight lifters, and 25 shooters, disc degeneration and bulging were most common among weight lifters; soccer players had similar changes in the L4-S1 discs. No significant differences were seen in the magnetic resonance images of runners and shooters. CONCLUSIONS: Maximal weight lifting was associated with greater degeneration throughout the entire lumbar spine, and soccer with degeneration in the lower lumbar region. No signs of accelerated disc degeneration were found in competitive runners. However, back pain was less common among athletes than control subjects and there were no significant differences in hospitalizations or pensions. No benefits were shown for vigorous exercise compared with lighter exercise with respect to back findings.

Adolescent↗
PubMed1995

Similarities in degenerative findings on magnetic resonance images of the lumbar spines of identical twins.

Although the etiology of most degenerative changes in the lumbar spine is unclear, genetic factors may play an important role. To investigate this link, we reviewed magnetic resonance images of the lumbar spines of identical twins to assess the degree of similarities in degenerative findings in the discs. Observers who were blinded to twinship evaluated sagittal T1-weighted and T2-weighted magnetic resonance images of the lumbar spines of forty male identical twins (twenty pairs) with respect to changes in the end plates, desiccation of the discs, bulging or herniated discs, and decrease in the height of the disc space. Similarities between co-twins were significantly greater than would be expected by chance. Whereas smoking status and age explained 0 to 15 per cent of the variability in the various degenerative findings in the discs, 26 to 72 per cent of the variability was explained with the addition of a variable representing co-twin status. These findings are compatible with a marked genetic influence and warrant further investigation.

Adult↗
PubMed1995

Giant cell tumor of bone. Curettage and cement reconstruction.

A retrospective review was conducted of all consecutive giant cell tumors treated by the senior author (JOJ) between 1975 and 1990 using the technique of aggressive curettage through a large bone window followed by acrylic cement reconstruction. Steinmann pins were used as reinforcement bars within the methacrylate in large lesions. Thirty-eight patients with a mean followup of 5.2 years (range, 2-16 years) were identified. Three (8%) recurrences are reported. There were no infections or mechanical failures of the construct. Functional results were good to excellent in 84% of patients. Ninety-five percent of patients reported good or excellent stability, no deformity, and emotional acceptance of the procedure. The recurrence rate with this protocol (8%) approached that associated with wide resection or amputation (0%-5%), and was lower than that seen with simple curettage and bone grafting (27%-55%). Acrylic cement reconstruction is a safe and effective procedure that provides local adjuvant therapy and immediate stability for early rehabilitation. The authors emphasize the importance of aggressive curettage of the lesion through a large bone window and suggest the use of reinforcement bars within the cement for large defects.

Adolescent↗
PubMed1994

New-onset sciatica after automated percutaneous discectomy.

This is a case report of a 24-year-old patient who underwent percutaneous discectomy at L5-S1 for relief of lower back pain. Postoperatively, new-onset acute right lumbar radicular syndrome developed and the postoperative MRI scan confirmed a far lateral extraforaminal disc herniation at L5-S1 with compression of the right nerve. This corresponded to the nucleotomy site of the probe. This case report emphasizes that all physicians who treat herniated nucleus pulposus should be well versed in all aspects of treatment including complications.

Adult↗
PubMed1994

Digital assessment of MRI for lumbar disc desiccation. A comparison of digital versus subjective assessments and digital intensity profiles versus discogram and macroanatomic findings.

During magnetic resonance imaging, a vast amount of digital data on anatomic structures is translated into images, which are then assessed subjectively. The development of an objective, sensitive method to directly assess the digital data would have clear benefits, particularly for clinical research on disc degeneration. The study goals were to develop a method of digital assessment of disc desiccation and to compare digital signal intensity profiles with discographic patterns and macroanatomic findings. Proton density-weighted MRIs were obtained from 45 males (9-77 years) and digital analysis was done with a freely selectable region of interest facility. The adjacent cerebrospinal fluid (CSF) was used as a reference for disc signal-intensity scores, and the disc to CSF-intensity ratio provided "adjusted digital scores." The CSF-adjusted digital method yielded reproducible scores that correlated with the subjective assessments. However, the CSF-adjusted digital scores were more sensitive than the subjective assessments, identifying findings that otherwise were undetected in younger subjects. Additionally, 10 cadaveric spines were evaluated using MRI with T2 and proton density-weighted sequences, discography, and macroanatomic dissection. MRI disc-intensity profiles were determined along a midsagittal line drawn through the disc. The profile of the digital scores along this line was then compared with discograms and macroanatomic sections. In all cases of disc degeneration on discograms, changes were present in the intensity profile. Based on both the living subjects and the cadaveric specimens, the digital assessments and disc intensity profiles appear to demonstrate disc degeneration, particularly in early stages.

Adolescent↗
PubMed1993

Complications of the Wiltse Pedicle Screw Fixation System.

The purpose of the current study is to retrospectively review the incidence and types of complications occurring using a single pedicle screw fixation system for lumbar spine fusions. For a 3-year period beginning in July 1987, 470 patients underwent spinal fusion and instrumentation with the Wiltse Pedicle Screw Fixation System. Although multiple configurations of the Wiltse System were included, the predominant construct was that of segmental pedicle screw fixation. Complications occurred in a total of 29 patients, for an overall complication rate of 6%. Among the complications were 10 wound problems (2%) that included 2 seromas requiring drainage and 3 superficial wound infections. The remaining five wound complications were deep wound infections requiring irrigation and debridement. The overall deep wound infection rate was 1%. Neurologic complications occurred in two patients, one with temporary foot drop and one with persistent L5 nerve root irritation confirmed by electromyogram (EMG). Both of these patients underwent anatomic workup, which failed to reveal any evidence of impingement by either screw or other hard tissue. Two intraoperative complications occurred, both involving fracture of the L5 pedicle. No adverse sequela resulted. There were 15 hardware complications, for an overall rate of 3%. This included four patients with broken screws (a total of eight screws). There were three failures at the screw-bone interface, as well as four patients with uncoupling of the screw rod linkage. In addition, there were four broken rods encountered. A total of 122 Wiltse devices were removed, for an overall removal rate of 25%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Observations of resorption of the posterior lateral bone graft in combined anterior and posterior lumbar fusion.

The past 10 years have seen the development of a surgical reconstructive procedure for the treatment of patients disabled with severe postlaminectomy syndrome. The technique involves anterior lumbar fusion, replacing the excised disc with bone graft, and under the same anesthetic, applying a posterolateral bone graft along with segmental instrumentation. The purpose of this report was to compare cases with fused and nonfused posterolateral grafts in cases where the anterior fusion was successful. Seventy-four interbody segments in 30 patients were fused while 47% (14 of 30) of the posterolateral bone grafts underwent resorption. Both allograft and autograft were used and this did not appear to influence the resorption seen at the 4-year follow-up period. The most likely factor to explain resorption of the posterolateral graft is deprivation of the proper mechanical forces in the lateral gutter by the simultaneous use of anterior lumbar interbody grafts.

Adult↗
PubMed1993

Can lumbar spine radiographs accurately determine fusion in postoperative patients? Correlation of routine radiographs with a second surgical look at lumbar fusions.

Controversy centers on the determination of surgical fusion in lumbar spinal patients. What method best determines the nature of surgical arthrodesis remains unanswered. Numerous studies have investigated the accuracy of different radiologic tests. Although the best method has not been determined, plain radiography is certainly the most widely used in many centers and reported in scientific articles. In most of the literature a poor agreement between radiographic interpretation and surgical findings was observed. The main reasons seemed to be the lack of an accurate method to assess the radiographs. The authors rely on a radiologist or spinal surgeon to estimate the success of bony fusion by reviewing a two-dimensional radiograph. The purpose of this study was to determine the accuracy of plain radiographs to predict the presence of a surgical fusion. Forty-nine patients underwent fusion site exploration in the course of hardware removal. All patients had a one- or two-level posterolateral fusion and posterior lumbar interbody fusion with pedicle screw/link rod instrumentation. Immediate preoperative anteroposterior and lateral radiographs were taken before hardware removal that included both visual assessment and a Kocher mechanical test. Two spinal surgeons and two musculoskeletal radiologists blindly judged the preoperative radiographs as to the absolute presence or absence of successful arthrodesis. A second review was repeated at 3 months. The overall agreement between radiographic assessment and actual surgical findings was 69%. The range among observers was 57-77%. The overall false positive rate was 42% (0-75%), while the false-negative rate was 29% (20-51%). Success of observed surgical arthrodesis at the time of the second look was 90% and this number was used as the standard in the agreement process. In comparing the radiographic observations with the surgical findings it is suggested that in one of five cases the plain radiographs underestimate the degree of fusion. This finding agrees with the authors' knowledge of osteoid and mineralized bone. The premineralized osteoid may be functionally fused, but appear radiolucent on radiographic film. Once solid trabecular bony bridging occurs radiographic identification of fusion is easier to determine.

Adult↗
PubMed1993

Percutaneous Lumbar Diskectomy.

The development of an approach for percutaneous lumbar diskectomy (PLD) began over 20 years ago. Since then, clinical investigations of manual and automated PLD techniques have recorded an average success rate of 50% to 70%. Currently, the indications for PLD include (1) a major complaint of acute unilateral leg pain localized to a single dermatome associated witha a single-disk herniation; (2) neurologic signs or symptoms appropirate to a single-disk herniation; (3) magnetic resonance imaginng, computed tomographic, or diskographic evidence of a single herniation contained within the annulus of the lumbar disk; and (4) failure of a well-managed course of conservative treatment to relive the pain and symptoms. Conventional laminotomy/laminectomy, with or without the use of a microscope or surgical loupes, remains the usual method of surgical care for symptomatic lumbar disk disease. The role of PLD awaits further prospective randomized controlled studies.

Journal Article↗
PubMed1992

Antisocial personality disorder, HIV risk behavior and retention in methadone maintenance therapy.

In a sample of 55 consecutive methadone maintenance admissions to our clinic, 42% were diagnosed with antisocial personality disorder (ASPD) using the National Institute of Mental Health Diagnostic Interview Schedule NIMH DIS. Individuals with ASPD exhibited greater risk for HIV infection as defined by more sexual contacts, needle use and equipment sharing. Data at 1 year follow-up were obtained on this group of patients. The objective was to compare the ASPD and non-ASPD groups with regards to demographics, drug abuse history, outcome and retention in treatment. There were no significant differences between the groups on any demographic or treatment outcome variables. Survival analysis indicated that there were no group differences in treatment retention. In conclusion, although there were no differences in treatment outcome between ASPD and non-ASPD groups it is possible that ASPD patients who drop out of treatment will be at higher risk for contracting and spreading HIV within the IV drug using population. These data also suggest that in this population the diagnosis of ASPD using primarily behavioral traits as measured in the NIMH-DIS-III, has little utility in predicting treatment outcome.

Adult↗
PubMed1992

Functional results after anterior lumbar fusion at L5-S1 in patients with normal and abnormal MRI scans.

The debate continues as to which patient responds best to surgical versus nonsurgical intervention for painful degenerative disc syndrome. Discography is often used as the basis for that decision. In a review of 53 cases followed for an average of 20 months after surgery, only 50% of patients with type I (contained) discography and normal magnetic resonance imaging findings were found to be improved. In those patients with types II and III (noncontained) discography and abnormal magnetic resonance imaging scans, a 75% success rate was seen. There was an overall 80% fusion rate for all patients who underwent anterior lumbar fusion at L5-S1. Average age was 34 years, with average length of disability from low-back pain of 11 months. All patients were placed in a similar presurgery and postsurgery rehabilitation protocol and had failed nonsurgical treatment options. In this matched group of patients, those with abnormal magnetic resonance imaging scans and abnormal discography, clearly fared better, with a 75% percent success rate versus 50% success rate in those with normal magnetic resonance imaging findings. This series raises the question as to whether those patients with normal magnetic resonance imaging findings are surgical candidates.

Adult↗
PubMed1992

Enzymatic production of acetaldehyde from ethanol in rat brain tissue.

The capacity for the brain to produce acetaldehyde (AcHO) from ethanol was determined in rat brain homogenates. Rat brains were perfused with saline-heparin solution and homogenized in a phosphate buffer. Varying amounts of tissue were incubated with ethanol (0-100 mM) for periods of up to 60 min. The reaction was stopped by the addition of desferrioxamine and ice-cold perchloric acid. Supernatants were treated with dinitrophenylhydrazine reagent, extracted with isooctane in the presence of an internal standard, and the derivatives were separated by HPLC. The addition of 4-methyl pyrazole (an alcohol dehydrogenase inhibitor) or metyrapone (a cytochrome P450 inhibitor) had no effect on the amount of recovered AcHO. On the other hand, treatment with the catalase inhibitors sodium azide, cyanamide, or 3-amino-1,2,4-triazole blocked the production of AcHO while the addition of exogenous peroxide or a peroxide-generating system enhanced the production of AcHO. Overall, these results suggest that AcHO may be produced in the brain during alcohol intoxication, through the action of the enzyme catalase.

Acetaldehyde↗
PubMed1992

Quality of self-care of patients with asthma.

In order to assess the quality of self-care of asthmatic patients in family practice, 150 patients were asked what they did when they felt an attack of asthma coming on. Twenty-four percent said they took no medication. Of the remaining 114 patients, only 49 took appropriate medication. Of these, however, most were not able to demonstrate correct use of their inhaler. This poor quality of self-care may contribute to the undertreatment of asthma in family practice. To improve the quality of care of asthmatic patients, comprehensive treatment is recommended, with the emphasis on improving self-care skills.

Adult↗