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Steven R Garfin

Publications and source records attributed to Steven R Garfin.

29 records · Page 2Linked to original sources
PubMed1993

An empirical evaluation of multidimensional clinical outcome in chronic low back pain patients.

Individuals with persisting pain often present a constellation of symptoms that includes pain, health-related impairment and dysphoric mood. It is now widely accepted that comprehensive assessment must address each of these dimensions. Despite recognition of the value of multidimensional assessment, no empirical efforts have validated the construct of a multidimensional clinical outcome presentation based on the dimensions of pain, impairment and dysphoric mood. We employed cluster analytic procedures on standard measures of pain, impairment and depression in chronic low back pain (CLBP) patients (n = 96) attending a general orthopedic clinic in order to empirically characterize multidimensional clinical outcomes. Results indicated that 3 groups could be identified reliably: (1) 'Chronic Pain Syndrome' (n = 25; high levels of pain, impairment and depression), (2) 'Positive Adaptation to Pain' (n = 24; high levels of pain with low levels of impairment and depression) and (3) 'Good Pain Control' (n = 47; low levels of pain, impairment and depression). The reliability of this cluster solution was supported by several tests of internal consistency. Discriminability of the clusters was examined across both the outcome measures themselves and several additional independent variables. The cluster solution was then cross-validated in an independent sample of pain clinic CLBP patients (n = 180) to test its generalizability. Finally the stability of the cluster dimensions over time was tested by re-assessing 36 CLBP patients 6 months after they initially were characterized into 1 of the 3 outcome groups on the same measures. MANOVA results indicated that the outcome groups were differentiated statistically across assessments. The multiple outcome measures did not change significantly across time, nor did the outcome groups change differentially across time on these measures. We conclude that the outcome dimensions of pain, impairment and depression are relatively stable phenomena that differentially describe CLBP patients.

Adult↗
PubMed1991

Pain and impairment beliefs in chronic low back pain: validation of the Pain and Impairment Relationship Scale (PAIRS).

Few validated instruments are available to assess beliefs and attitudes that patients have regarding pain, or ability to function despite discomfort. The Pain and Impairment Relationship Scale (PAIRS) was developed to tap these important beliefs and attitudes in chronic pain patients. Preliminary data indicate that the PAIRS is internally consistent and significantly related to impairment in a highly selected pain clinic sample of patients, including some chronic low back pain patients. The present study was designed to extend the validation of the PAIRS to a more general sample of chronic benign low back pain patients. Furthermore, additional tests supported the discriminant, convergent and divergent validity, as well as the reliability and relative independence from favorable self-report response bias of the PAIRS, by respectively demonstrating that: (1) the impairment beliefs assessed with the PAIRS were more prominent in chronic low back pain (CLBP) patients than in matched non-pain, healthy controls; (2) scores on the PAIRS were significantly related to measures of physical impairment, but not to physicians ratings of disease severity; (3) the impairment beliefs assessed with the PAIRS are readily distinguishable from cognitive distortions and emotional distress; (4) PAIRS scores for chronic low back pain patients are relatively consistent over time; and (5) PAIRS scores are not significantly associated with measures of favorable self-report response bias. We conclude that the PAIRS has demonstrated at least preliminary utility for applications by researchers and clinicians interested in chronic pain.

Adult↗
PubMed1991

Prevalence, onset, and risk of psychiatric disorders in men with chronic low back pain: a controlled study.

This study used structured diagnostic interviews and DSM-III criteria to assess lifetime prevalence and pre-morbid risk of psychiatric disorder in a sample of men with long-standing chronic back pain (CLPB) attending a primary care clinic. A control group of age and demographically matched men without history of back pain was also studied. Compared to controls, men with CLBP had significantly higher lifetime rates of major depression (32% vs. 16%), alcohol use disorder (64.9% vs. 38.8%), and a major anxiety disorder (30.9% vs. 14.3%). Almost all CLBP men ever experiencing a mood disorder reported recurrent, not single, episodes. The 6 month point prevalence of major depression, but not other disorders, was also significantly elevated for men with CLBP. In CLBP, the first episode of major depression generally (58.1%) followed pain onset. While the initial major depressive episode usually commenced within the first 2 years of established pain, late onset mood disorder was also common. By comparison in most cases (81%) onset of alcohol use disorders considerably preceded pain. When an age-matching procedure was used to gauge relative vulnerability to psychiatric illness in patients and controls, CLBP patients had significantly higher pre-pain rates of alcohol use disorder but not depression. After age of pain onset, CLBP subjects had over 9 times the risk of developing major depression, but had similar rates of developing alcoholism. We conclude that (1) alcohol use disorders rather than depression may increase risk of developing CLBP, and (2) risk of new onset and recurrent major depression remains high for men throughout their pain career. This suggests that psychological adaptation to long-standing pain may be less successful than previously thought, especially with regard to recurrent mood disorder.

Adult↗
PubMed1988

Depressed mood in chronic low back pain: relationship with stressful life events.

This study investigated the relationship between stressful life events and depressed mood in chronic low back pain (CLBP), using both self-report and observer-rated assessments of life happenings and depression. We hypothesized that CLBP patients with depressed mood (N = 15) would report significantly more untoward life events and ongoing life difficulties compared to CLBP patients without depressed mood (N = 17) and controls (N = 19). This prediction was confirmed. Subjects also were rated as being either in a high stress or low stress condition. Patients with depressed mood were more likely to be in the high stress condition than were either non-depressed patients or volunteers. Furthermore, the increased stress reported by the distressed group appeared to be a direct consequence of back pain-related life events, rather than from other life problems. We conclude that previously reported associations between life events and CLBP are a function of the relationship between stressful life events and depressive symptoms, which are prevalent in CLBP.

Adult↗
PubMedDate not supplied

Response of fractured osteoporotic bone to polymethylacrylate after vertebroplasty: case report.

BACKGROUND CONTEXT: Polymethylmethacrylate (PMMA) is the most commonly used bone cement for vertebroplasties to treat osteoporotic vertebral compression fractures (VCFs). Several studies have described the reaction of normal bone to PMMA, but it is still unclear how fractured osteoporotic bone responds to PMMA. PURPOSE: To describe the response of fractured osteoporotic bone to PMMA after vertebroplasty. STUDY DESIGN/SETTING: Case report. METHODS: A 69-year-old woman with a previous vertebroplasty at T8 to treat an osteoporotic VCF was admitted to the hospital after she developed lower extremity motor weakness, diffuse hypoesthesia and decreased rectal tone. Magnetic resonance imaging studies of the thoracic spine showed that she had severe spinal cord compression at the level of T8 and T9, as well as akyphotic deformity. A corpectomy of T8 and T9 was performed as part of a spinal cord decompression procedure. Tissue from vertebral body T8, intervertebral discs T7-T8 and T8-T9 and the PMMA implant were then submitted for histologic evaluation. RESULTS: Vertebral body T8 demonstrated viable bone trabeculae, osteoid. fibrosis, granulation tissue and multinucleated giant cells containing PMMA. Scattered necrotic bone fragments were identified throughout the vertebral body, most evident near the PMMA. PMMA leakage into the T7-T8 disc was identified without significant disc inflammation or necrosis. CONCLUSION: Fractured osteoporotic bone is capable of undergoing a reparative healing response after vertebroplasty using PMMA.

Aged↗
PubMedDate not supplied

Topical high-molecular-weight hyaluronan and a roofing barrier sheet equally inhibit postlaminectomy fibrosis.

BACKGROUND CONTEXT: The relevance of epidural fibrosis to failed back surgical outcomes remains controversial. Previous studies on the correlation between epidural fibrosis and clinical outcome after laminectomy are inconclusive, and clinical approaches applied to reduce postlaminectomy spinal canal scarring have produced mixed outcomes. PURPOSE: Improved preclinical models are required to address the fundamental question of the relationship between postlaminectomy fibrosis and chronic pain. This study is directed at establishing small animal postlaminectomy models characterized by significantly reduced scar within the spinal canal postoperatively. Such preclinical models are offered as a platform for future studies to explore the potential relationship between postlaminectomy epidural fibrosis and persistent neuropathy with its potential for altered spinal mechanisms for pain processing, so-called spinal facilitation. Such experiments could be constructed in these models for comparison of pain behavior and its underlying neurochemistry both in the presence and absence of extensive postlaminectomy epidural scar. STUDY DESIGN/SETTING: A modified rat laminectomy model was employed to assess epidural fibrosis using a quantitative biochemical collagen assessment approach along with correlative histology. This group served as the control for comparison with groups in which antifibrotic measures were employed. We compared antifibrotic efficacy of a bioabsorbable roofing barrier sheet placed over the laminectomy defect with topical high-molecular-weight hyaluronan (HMW HA) gel, each applied postoperatively to prevent proliferative epidural scarring. Routine biomechanical tensile strength testing was employed to assess wound-healing strength. METHODS: A bilateral laminectomy (L5 and L6) with associated unilateral disc injury (L5-L6) was performed in 98 male Harlan Sprague-Dawley rats. The laminectomy models described incorporated a unilateral disc injury at L5-L6 because herniated disc material has been shown to contribute proinflammatory cytokines in the postoperative wound. Five groups were employed for the study: 1) normal controls without surgery; 2) a laminectomy-disc injury group without treatment; 3) a laminectomy-disc injury group treated with topical HMW HA gel; 4) a laminectomy-disc injury group treated with 0.2-mm thick bioabsorbable roofing barrier sheet in which a protected space was maintained between overlying paraspinous muscles and the dura and 5) a 0.02-mm thin barrier sheet treatment group in which the sheet was placed directly on the dura. The animals were sacrificed at 3- and 8-week postoperative intervals for analysis. The dissected specimens were studied biochemically for hydroxyproline content to estimate total collagen within the canal and on the dura between L4 and L7. Additional specimens were prepared histologically and stained with Masson-Goldner Trichrome stain to confirm presence of proliferative collagen and to describe the presence or absence of wound-healing scar adherence to the dura. The surgical incisions were studied biomechanically by uniaxial tensile testing to determine ultimate force, strain and prefailure stiffness. Statistics were performed using analysis of variance. RESULTS: Gross appearance and histology studies showed that the untreated laminectomy group demonstrated postoperative scar formation that is adherent between the wound and the dorsum of the dura mater in both 3- and 8-week groups. Proliferative scar was substantially increased grossly between the 3- and 8-week intervals. By gross observation there was adherence of the L5 spinal nerve to the underlying disc and adjacent pedicle on the disc injury side. Gross observation of treatment groups, in contrast, disclosed that both the 0.2-mm thick roofing barrier sheet and topical HMW HA gel each prevented scar attachment to the dural sleeve at both the 3- and 8-week postoperative intervals. Furthermore, both the HMW HA gel and 0.2-mm thick roofing barrier sheet treatment groups had significant reduction of total collagen content in the laminectomy specimens measured biochemically at the two time periods compared with the untreated controls. Histologically, the HMW HA gel and the 0.2-mm thick barrier sheet findings were consistent with the gross observations concerning lack of adherence between scar of the overlying wound and the dura. Notably, both the 0.2- and the 0.02-mm barrier sheets became enveloped by a fibrotic envelope consistent with a foreign body reaction. In the group in which the 0.02-mm thin sheet was placed within the canal on top of the dura, there was an increase of fibrosis around the sheet within the canal leading to a space-occupying mass within the canal. Although the 0.2-mm thick roofing barrier placed external to the canal became enveloped by scar, it appeared to attract proliferative scar away from the epidural space, leaving the dura relatively free of scarring or adherence to overlying tissues. The mechanical properties of the incisional wound increased significantly between 3 and 8 weeks. The ultimate strength, stress, strain and stiffness of the several groups were similar at each time point. CONCLUSION: These results provide two preclinical rat laminectomy models of potential usefulness for the future study of the relevance of epidural fibrosis to behaviorally defined pain states, and for the study of the potential of an altered neurochemical signature in postlaminectomy pain conditions. Such preclinical models have become standard in studies of pain behavior and its neurochemistry in preclinical sciatic nerve and spinal nerve injury models, and should be of utility in the studies of postlaminectomy fibrosis. There was progressive scar proliferation and maturation in the untreated postlaminectomy group in the postoperative interval between 3 and 8 weeks. HMW HA gel applied topically and a 0.2-mm thick bioabsorbable Macropore sheet used as a roofing barrier each significantly reduced postlaminectomy proliferative scar without affecting the integrity of incisional wound healing. However, if the 0.02-mm thin barrier sheet used in this study is placed within the canal in contact with the dura and adjacent to the pedicles, the process of reabsorption results in a fibrotic mass within the canal. The preferred barrier sheet placement for this model is clearly in a roofing position bridging over the open epidural space. It must be placed in a manner to block off the paraspinous muscle healing response and still leave a gap between the sheet and the dura.

Adjuvants, Immunologic↗
PubMedDate not supplied

History and evolution of disc replacement.

Total joint replacement has revolutionized the treatment of limb arthritides. Spinal arthroplasty is emerging as a treatment for spinal disc degeneration. The purpose of this review is to highlight the evolution of artificial interventions for nucleus and total disc replacement. This review will provide the foundation for the understanding of present and future technologies in the field.

Arthroplasty, Replacement↗
PubMedDate not supplied

Topical high molecular weight hyaluronan reduces radicular pain post laminectomy in a rat model.

BACKGROUND CONTEXT: A controversy exists about the mechanism of causation of the post-laminectomy pain syndrome. Some believe that epidural scarring, and attendant spinal nerve and nerve root scarring and tethering to the disc or pedicle at the site of surgery contributes to post-laminectomy pain in such patients. However, clinical outcome studies on this question are inconclusive and the assertion remains controversial. Definitive studies to help resolve the question are needed. Previously our laboratory has reported on a preclinical post-laminectomy model that mimics the postoperative proliferative fibrotic response grossly, as well as by biochemical assessment of the collagen content within the spinal canal. The post-laminectomy fibrotic response was attenuated in that study by application of a topical antifibrotic (high molecular weight hyaluronan gel) or by insertion of an absorbable roofing barrier (0.2-mm-thick Macropore sheet material) over the laminectomy defect before wound closure. The question remains of relevance of the attenuation of the fibrotic response to post-laminectomy chronic pain syndromes. PURPOSE: The purpose of this study is to evaluate the effect of therapeutic attenuation of proliferative scar within the spinal canal post laminectomy on the pain-related behavioral response in a preclinical rat model. STUDY DESIGN/SETTING: An established L5-L6 rat laminectomy model with a unilateral L5-6 disc injury was employed to assess postoperative proliferative fibrosis of the L5 spinal nerves using quantitative biochemical hydroxyproline assessment of the collagen content in four experimental groups. These observations were correlated with gross descriptions of spinal nerve scarring or tethering. Associated manifestations of a sensory pain-related response in the L5 spinal nerve receptor area of the hind paws was studied using standard tactile allodynia assessment with the von Frey hair technique. The tactile allodynia findings were supplemented by weekly descriptors of behavioral pain manifestations. METHODS: Bilateral laminectomies at L5 and L6 and a unilateral right disc injury (L5-6) were performed on 35 male adult Sprague-Dawley rats, weighing 400+ grams (approved by the VA Institutional Animal Care Use Committee). The study consisted of four groups: 1) normal nonoperative control; 2) a sham-operated group; 3) an untreated laminectomy-disc injury group; and 4) a laminectomy-disc injury treatment group in which 0.1 cc topical high molecular weight hyaluronan (HMW HA) gel was layered over the dura and into the laminectomy canal before closure. Before animals were entered into the study, they were checked for the presence of abnormal response to the tactile testing procedure of the L5 sensory receptor area. Animals exhibiting anomalous responses were excluded from the study. Behavioral testing for tactile allodynia was performed at weekly intervals post laminectomy beginning at 3 weeks. Pain-related behavior was characterized at weekly intervals. A behavioral test cage with a wire mesh floor allowed for tactile allodynia testing. Graduated von Frey hairs whose stiffness increased logarithmically from 0.41 to 15 g were used for tactile allodynia tests. The animals were killed 8 weeks postoperatively for analysis. The dissected spinal nerve and nerve root specimens were studied biochemically for hydroxyproline content to estimate total collagen in and around the L5 neural structures. Statistical analyses were performed using analysis of variance and a Fisher comparison t test. RESULTS: The major observations on the untreated preclinical post-laminectomy rat model previously described by this laboratory were confirmed. All untreated animals developed a tail contracture concave toward the right (disc injury side) consistent with asymmetrical lumbar muscle spasm. Only one animal in the HA gel treatment group had a tail contracture. It was of mild degree and occurred in an animal that demonstrated slightly increased right L5 tactile sensitivity. Gross inspection of the dissected specimens demonstrated spinal nerve scarring and tethering to the disc and pedicle greater on the right than the left in untreated animals, findings that were markedly reduced in the treatment group. Collagen content of the L5 spinal nerve and nerve roots with attached scar were significantly lower in the HA gel treatment group than in the untreated laminectomy group (p=.0014). Pain behavioral testing of the L5 receptor area of the right hind paw in the untreated laminectomy group showed markedly increased sensitivity to tactile allodynia testing compared with the corresponding limb of the control group (p=.0001), to the corresponding limb of the sham group (p=.0001), and compared with the HMW HA gel treatment group (p=.0010). Comparisons of the pain behavioral data between the sham and the post-laminectomy HA gel treatment group and the control animals lacked statistical significance. CONCLUSION: This study supports the concept of a relationship between perineural fibrosis and radicular neuropathy in the model described, and emphasizes the role of disc injury and spinal nerve retraction in the post-laminectomy fibrotic process. Furthermore, it shows promise for preliminary assessment of interventions with other anti-inflammatory agents, for characterization of the neurochemical profile of the post-laminectomy pain state, and for exploration of newer pharmaceutical agents potentially useful in the prevention or management of the post-laminectomy syndrome. Post-laminectomy scar is but one of many potential causes of the post-laminectomy pain syndrome. Furthermore, a cautionary note must be emphasized as in all studies using preclinical models, conclusions drawn from the studies cannot be extended directly to patients without confirmatory clinical follow-up studies.

Administration, Topical↗
PubMedDate not supplied

Percutaneous balloon kyphoplasty for the correction of spinal deformity in painful vertebral body compression fractures.

Vertebral body compression fractures can cause chronic pain and may result in progressive kyphosis. Although vertebroplasty has been used to treat pain, it does not attempt to restore vertebral body height and eliminate spinal deformity. Percutaneous balloon kyphoplasty is a novel technique, which involves the introduction of inflatable bone tamps into the fractured vertebral body for elevation of the endplates, prior to fixation of the fracture with bone cement. Our initial experience with this minimally invasive procedure indicates that percutaneous balloon kyphoplasty can be efficacious in the treatment of painful, osteoporotic vertebral compression fractures.

Adult↗
PubMedDate not supplied

Minimally invasive treatment of osteoporotic vertebral body compression fractures.

BACKGROUND CONTEXT: Seven hundred thousand osteoporotic compression fractures occur yearly. Approximately 260,000 lead to severe pain, and 150,000 require hospital admissions. Associated with the fractures are increased loss of pulmonary function (90% decreased forced vital capacity per fracture level) and an increase in gastrointestinal complications (early satiety, and therefore malnutrition) and increased mortality (greater than that associated with osteoporotic hip fractures). New treatments available for these painful disorders include kyphoplasty and vertebroplasty. The injections of polymethylmethacrylate into the vertebrae (vertebroplasty technique) decrease pain and improve function. Kyphoplasty (percutaneous placement of a balloon tamp to improve height and create a void, and then the filling of this void with cement) improves function, decreases pain and helps realign the spine. PURPOSE: To compare kyphoplasty and vertebroplasty, and assess their various merits, treatment indications, and outcomes. STUDY DESIGN/SETTING: Literature review with presentation of early results of a national, clinical study. METHODS: Literature review for overview. Retrospective chart/patient review for clinical data presented on kyphoplasty. RESULTS: Ninety-five percent of individuals treated for painful osteoporotic compression fractures have significant improvement in symptoms and function after kyphoplasty or vertebroplasty. Kyphoplasty improves vertebral body height and kyphotic alignment by 50%, if performed within 3 months of the onset of the fracture collapse. CONCLUSIONS: Vertebroplasty and kyphoplasty both have roles in the treatment of painful osteoporotic compression fractures. Only kyphoplasty helps improve height and kyphosis, which should help prevent pulmonary and gastrointestinal complications.

Humans↗