Biomedical subjects

Steven R Garfin

Publications and source records attributed to Steven R Garfin.

At least 19 recordsLinked to original sources

PubMed2006

Balloon kyphoplasty for symptomatic vertebral body compression fractures results in rapid, significant, and sustained improvements in back pain, function, and quality of life for elderly patients.

STUDY DESIGN: Prospective, single-arm interventional cohort. OBJECTIVE: To evaluate the safety and effectiveness of balloon kyphoplasty to treat symptomatic vertebral body compression fractures (VCFs). SUMMARY OF BACKGROUND DATA: VCFs treated nonoperatively can diminish function and quality of life, and lead to chronic health effects. The short-term safety and effectiveness of balloon kyphoplasty for symptomatic VCFs are well-documented, but long-term follow-up is needed. METHODS: A total of 155 elderly patients with symptomatic VCFs were enrolled in a prospective, multicenter treatment study of balloon kyphoplasty at 19 geographically diverse US centers. Outcomes included back pain severity, bedrest, and limited activities because of back pain, back disability score, and SF-36 Medical Outcomes Survey, at 7 days (visual analog scale only), and 1, 3, 12, and 24 months after treatment. RESULTS: Patients reported severe back pain (15/20 on visual analog scale) interfering with daily activities 90% of days per month before kyphoplasty. Physical functioning and quality of life were also markedly impaired. Statistically significant (P < 0.001) improvements occurred in all pain, functional, and mental health outcomes at the first follow-up after treatment and were maintained for 24 months. CONCLUSIONS: Elderly patients with symptomatic VCFs had rapid, significant, and sustained improvements in back pain, back function, and quality of life following balloon kyphoplasty.

Aged↗

PubMed2006

High-molecular-weight hyaluronan inhibits macrophage proliferation and cytokine release in the early wound of a preclinical postlaminectomy rat model.

BACKGROUND CONTEXT: Failed back syndrome, a condition that affects 3-14% of postoperative spine patients, is characterized by the recurrence of radicular pain after spinal decompression. The source of this pain in some patients is thought by many investigators to be the result of epidural scarring and nerve root tethering, but this is controversial. We have previously demonstrated that in a disc-injury model the untreated postlaminectomy rats develop a significant proliferative fibrous response at 8 weeks with spinal nerve scarring to the disc and adjacent pedicle, and increased sensitivity to tactile allodynia testing in the related sensory dermatome. Topical high-molecular-weight hyaluronan (HMW HA) moderates both the proliferative fibrosis and the behavioral pain response. PURPOSE: Our purpose is to study the time-related changes in the proinflammatory cytokine and monocyte/macrophage profiles in the epidural space in the early postlaminectomy untreated and HMW HA gel treated groups. STUDY DESIGN/SETTING: A modified rat laminectomy with disc injury model was employed to assess epidural fibrosis between and around the spinal nerves using a quantitative immunohistochemistry assessment approach along with correlative enzyme-linked immunosorbent assay analysis. METHODS: Lumbar laminectomies at L5 and L6 with a L5-L6 disc injury were performed on 120 adult male Sprague-Dawley rats. The rats were then randomized into one of two groups: untreated and treated. The treatment group received a one-time topical application of 0.1 cc of HMW HA gel directly to the laminectomy site just before wound closure. The rats were then randomly subdivided into survival periods of 24 hours, 72 hours, and 7 days. Immunohistochemistry was performed on fresh frozen sections and stained for interleukin-1 beta (IL-1beta) and monocytes/macrophages (ED-1) using monoclonal antibodies and 3, 3' diaminobenzidine (DAB) chromogen. The amount of stain in each specimen was then quantified using the National Institutes of Health computer imaging analysis system. RESULTS: The semiquantified data from the histological specimens demonstrated significant decreases in the IL-1beta and IL-6 infiltration observed at 24 hours in the epidural space and around the right nerve root (p=.0296 and 0.0195, respectively) in the HA gel treated group. Additionally, significant decreases in the monocyte/macrophage infiltration were observed at 72 hours in the epidural space around the left nerve root (p=.0039) and right nerve root (p=.0072) in the HA gel treated group. At 7 days, IL-1beta, IL-6, and macrophage infiltration of the wound had declined in both the HA gel and the untreated groups. The enzyme-linked immunosorbent assay data support the same pattern as seen in the histological results. CONCLUSION: These results demonstrate that treatment of postlaminectomy wounds with HMW HA gel decreases the number of monocytes and macrophages and the concentration of certain cytokines in the early inflammatory phase of healing. There are several plausible explanations for this effect. First, the HMW HA may block the interaction of short-chain low-molecular-weight HA with proinflammatory cell surface receptors. The interaction of these short-chain oligo-HA fragments, upon cell-surface receptor binding, induces changes in inflammatory cells that lead to increased cell motility and migration into the wound area. Second, the addition of exogenous HMW HA may cause a dilution effect in the wound, thereby decreasing the concentration of inflammatory cells in the extracellular matrix of the region of injury. Finally, the migration of inflammatory cells may be decreased in the viscous environment of the HMW HA. The first explanation is believed by the authors of this paper to be the more likely mechanism. HMW HA probably mutes the proinflammatory effects of the low-molecular weight fragments, leading to decreased inflammation, and thus decreased fibrosis and scar formation noted in the chronic model.

Adjuvants, Immunologic↗

PubMed2006

Pullout strength of thoracic pedicle screw instrumentation: comparison of the transpedicular and extrapedicular techniques.

STUDY DESIGN: In vitro biomechanical comparison of two methods of pedicle screw placement in cadaveric thoracic spine vertebrae. OBJECTIVE: Compare the biomechanical integrity of extrapedicular and transpedicular screw fixation under axial and sagittal pullout loads. SUMMARY OF BACKGROUND DATA: Extrapedicular screw placement has been advocated as a safe and effective alternative to the transpedicular screw in thoracic vertebrae. Rigorous biomechanical comparison of these two techniques is presently lacking in the literature. METHODS: Thirty-seven vertebral bodies were dissected from six cadaveric thoracic spines. Each body had two polyaxial 5.0-mm screws placed: one transpedicular and one extrapedicular. The 62 screws were randomly designated for one of two loading methods: axial or sagittal. Failure load (N), taken as maximum force on the load-deformation curve, and stiffness (N/mm), calculated between 50 N and 400 N, were measured. RESULTS.: Transpedicular screws were statistically stronger in both testing methods (P = 0.008). Load direction, whether axial or sagittal, had no bearing on pullout strength (P = 0.6). CONCLUSIONS: These data indicate that transpedicular screws are biomechanically superior to extrapedicular screws. This difference is small, however, and we think that extrapedicular screws offer an excellent alternative when anatomy dictates their use with other screws in segmental spinal constructs.

Aged↗

PubMed2006

Paraspinal muscle vasculature contributes to posterolateral spinal fusion.

STUDY DESIGN: Study of posterolateral fusions in a rabbit model. OBJECTIVES: To characterize the contribution of paraspinal musculature to the healing of posterolateral spinal fusions in a rabbit model. SUMMARY OF BACKGROUND DATA: Previous studies have demonstrated that successful spinal arthrodesis requires vascular ingrowth from adjacent decorticated bone. In other areas of the body, such as the tibia, vascular ingrowth from the surrounding musculature has also been shown to be important. The role of the surrounding paraspinal musculature in spinal fusions has yet to be assessed. METHODS: Twenty-five New Zealand white rabbits underwent posterolateral spinal fusion. One side of the animals was treated with autograft alone and served as the control group. On the contralateral side, the autograft was contained within porous or nonporous barrier sheets. Following euthanization, high-resolution radiographs, CT scans, and histologic analyses were performed to assess fusion and characterize vascular ingrowth. RESULTS: Using histologic evaluation, the fusion rate in the porous group was 90%, in the nonporous group 40%, and in the control group 55%. Vascular ingrowth was evident from the muscle through the porous sheet into the fusion mass. CONCLUSIONS: These results support our hypothesis that the paraspinal musculature provides important vascular ingrowth into the fusion site. Use of a porous barrier sheet appears to improve fusion by preventing muscle interposition while allowing vascular ingrowth from surrounding muscle.

Animals↗

PubMed2006

Fungal infections of the spine.

UNLABELLED: Fungal infections of the spine are relatively uncommon. Fungi such as Coccidioides immitis and Blastomyces dermatitidis are limited to specific geographical areas whereas cryptococcus, candida, and aspergillus are found worldwide. Candida and aspergillus are normal commensals of the body and produce disease in susceptible organisms when they gain access to the vascular system through intravenous lines, during implantation of prosthetic devices, or during surgery. For the other fungi, spinal involvement usually is the result of hematogenous or direct spread of organisms from an initial pulmonary source of infection. Involvement of the vertebral bodies can lead to vertebral compression fractures and gross deformity of the spine. Spread of infection along the anterior longitudinal ligament can lead to psoas or paravertebral abscesses. Early recognition of the disease requires a high index of suspicion, proper travel history, and a detailed physical examination. Treatment relies on the prompt institution of appropriate pharmacotherapy and constant monitoring of clinical progress. Resistance to medical therapy, spinal instability, and neurologic deficits are indications for débridement and stabilization with spinal fusion. Prognosis depends on the premorbid state of the patient, the type of fungal organism, and the timing of treatment. LEVEL OF EVIDENCE: Level V (expert opinion). Please see the Guidelines for Authors for a complete description of levels of evidence.

Antifungal Agents↗

PubMed2005

Cervical disc replacement.

STUDY DESIGN: Review article. OBJECTIVE: To critically review the state of the emerging field of cervical disc replacement. SUMMARY OF BACKGROUND DATA: Although anterior cervical decompression and fusion (ACDF) has been used successfully in the treatment of symptomatic radiculopathy and/or myelopathy, biomechanical studies have reported the deleterious effects of cervical fusion on adjacent level kinematics. Proponents of cervical disc replacement claim that maintenance of motion at the operated level will reduce the incidence of adjacent level degeneration and improve long-term clinical outcomes when compared with ACDF. METHODS: A systematic review of the literature dealing with cervical disc replacement and technologies of arthroplasty design that may have relevance to the cervical spine. A review of the design characteristics and published clinical data for cervical prostheses undergoing Investigational Device Exemption (IDE) study in the United States is provided. RESULTS: Current cervical disc replacement designs include one-piece implants and implants with single- or double-gliding articulations with either metal-on-metal or metal-on-polymer bearing surfaces. Reports of in vitro wear testing have claimed substantially less wear for cervical implants than that seen with prosthetic hips and knees. Short-term clinical results after decompression and cervical disc replacement for the treatment of cervical radiculopathy and/or myelopathy are encouraging. Prospective, randomized trials are lacking. CONCLUSIONS: Cervical disc replacement is an innovative technology that preserves motion at the instrumented level/s and will potentially improve load transfer to the adjacent levels compared with fusion. Clinical reports of success of cervical total disc replacement are encouraging but are also quite preliminary. As the U.S. IDE studies are completed, a clearer role for the place of cervical disc replacement in the spine surgeon's armamentarium should emerge.

Arthroplasty, Replacement↗

PubMed2005

Strut allograft union and remodeling using rhBMP-2 in a spinal corpectomy model.

STUDY DESIGN: Growth factor in a collagen sponge carrier was compared to autograft, both packed within an allograft strut following corpectomy in a bovine spinal model. OBJECTIVE: To evaluate incorporation of cortical strut allografts after lumbar corpectomy, comparing augmentation with recombinant human bone morphogenetic protein-2 (rhBMP-2) to local autograft. SUMMARY OF BACKGROUND DATA: Autogenous strut grafts are the gold standard for successful fusion in reconstruction following corpectomy; however, significant donor site morbidity can occur. Recent studies describing consistently successful anterior interbody fusions with BMP augmentation suggest an exciting prospect of unlimited and potent grafting material for these difficult fusions. METHODS: Sixteen calves underwent L3 corpectomy with instrumented strut allograft reconstruction. The rhBMP-2 impregnated collagen sponges filled the empty medullary canal of the allograft in 8 animals. Eight animals had the allograft strut filled with local autogenous bone. After 4 months, the lumbar spines were harvested for radiographic, biomechanical, and histologic evaluation. RESULTS: Computerized tomography revealed allograft fusion in 7 of 8 autograft specimens and 8 of 8 BMP specimens. The BMP treated group had denser bone at the ends of the cortical allograft, but a central void persisted. Autograft filled struts maintained a more uniform distribution of less organized bone throughout the strut canal. Histologic assessment verified remodeling and incorporation of the allografts for both groups. Biomechanical testing confirmed no significant difference in fusion strength between groups. CONCLUSIONS: Large cortical strut allografts (after lumbar corpectomy) supplemented with rhBMP-2 had incorporation and fusion strength comparable to allografts enhanced with cancellous autograft.

Animals↗

PubMed2005

Spinal instability: the orthopedic approach.

The determination of spinal stability remains an important task of the spine surgeon, as treatment strategies rely heavily on this assessment. However, a clinically useful definition of spine stability remains elusive. Numerous classification systems have been proposed: White and Panjabi proposed a checklist point system to assess spinal stability for each of the cervical, thoracic, and lumbar spines. This remains one of the best recognized systems to date. Denis proposed that spinal integrity depended on the three-column system (anterior, middle, and posterior) and used it to describe thoracolumbar fractures. The spine is considered unstable when any two of the three columns are disrupted. These two classification systems are designed for traumatic injuries and do not explain other causes of instability. In the end, numerous factors must be taken into account when determining spinal stability. These include the disease process causing the injury, the medical and neurologic status of the patient, the anatomic site, and findings on imaging studies.

Humans↗

PubMed2005

Axial load-dependent cervical spinal alterations during simulated upright posture: a comparison of healthy controls and patients with cervical degenerative disease.

OBJECT: The objectives of this study were to simulate the upright loading condition in the cervical spine by applying a new compression device during supine posture and to assess intervertebral angles and cross-sectional areas of the spinal cord and dural tube before and during axial compression. METHODS: A magnetic resonance (MR) imaging-compatible device was developed to create axial compression with the patient in the supine position. Lateral radiographs were obtained in upright and supine positions with an axial load of 0% (supine) and by applying a cervical compression device at 7, 10, and 13% of body weight (BW) in 18 control individuals and seven symptomatic patients with cervical degenerative disc disease (DDD). Additionally, cervical MR images acquired in 17 controls and 12 patients were compared before and during an axial load of 8.4% BW in terms of anteroposterior diameter and cross-sectional area of the dural sac. The supine intervertebral angles with loads of 0, 7, 10, and 13% of the individuals' BW relative to upright posture were -8.1+/-1.3, -2.3+/-1.4, 1.3+/-1.9, and 2.8+/-2 degrees, respectively. Subsequent axial force was interpolated as 8.9% of BW to simulate upright cervical spine alignment. Under an axial loading similar to that created by the upright posture, the dural sac narrowed at the C5-6 interspace in asymptomatic individuals and at the C6-7 interspace in patients with cervical DDD. CONCLUSIONS: This cervical compression device may be a useful tool to simulate upright cervical spinal alignment. The results of this study help in understanding the pathophysiology of symptoms related to cervical degenerative disorders in upright posture.

Adult↗

PubMed2004

A preclinical post laminectomy rat model mimics the human post laminectomy syndrome.

Chronic low back pain with sciatica complicating post laminectomy surgery is poorly understood. It is likely that some aspects of persistent pain of the syndrome results from spinal facilitation in which there is lowering of pain excitation levels. A small animal preclinical model is needed that mimics the clinical condition to permit detailed studies of the underlying altered neurochemistry of the sensory pathways. We propose herein a rat laminectomy model containing the elements required for study of the neurobiology of the condition. The model consists of a surgical laminectomy that includes L5 spinal nerve manipulation and disc injury, elements necessarily employed in human disc herniation surgery. At 8 weeks post laminectomy the proposed model demonstrates paraspinous muscle spasm, tail contracture, behavioral pain behavior, tactile allodynia, epidural and nerve root scarring, and nerve root adherence by scar to the underlying disc and adjacent pedicle. Two underlying pain facilitation states are invoked in the clinical condition: (1) an inflammatory state required to achieve wound healing; and (2) a nerve injury state resulting from nerve manipulation and subsequent epidural scarring, spinal nerve scarring, and spinal nerve tethering to the adjacent disc and pedicle. Both pain facilitation states are active in the model.

Analysis of Variance↗

PubMed2004

Temperatures within the lumbar disc and endplates during intradiscal electrothermal therapy: formulation of a predictive temperature map in relation to distance from the catheter.

STUDY DESIGN: Temperatures were measured in human cadaveric lumbar discs during intradiscal electrothermal therapy. OBJECTIVES: To determine if sufficient temperatures for collagen denaturation and nociceptive ablation can be achieved at clinically significant distances from the intradiscal electrothermal therapy heating catheter. SUMMARY OF BACKGROUND DATA: Previous cadaveric studies have contested the ability of the intradiscal electrothermal therapy catheter to produce sufficient temperatures to denature collagen and cause neural ablation within the posterior anulus of the disc. However, these experiments used clinically unrepresentative device placements along the anterolateral anulus. METHODS: Intradiscal electrothermal therapy was performed in 14 human cadaveric discs. Devices were inserted using a standard posterolateral approach to orient the heating catheter along the posterior anulus. Temperature recordings were collected using multiple sensors placed along the posterior anulus, anterior anulus, and endplates. RESULTS: Temperatures greater than 60 C and 65 C were achieved in 14 and 5 specimens, respectively, at distances up to 2 mm from the catheter. Between 2 and 4 mm, more than 60 C was achieved in all specimens. More than 45 C was achieved in all specimens at distances of 9 to 14 mm from the device. CONCLUSIONS: Temperatures sufficient for collagen denaturation and nociceptive ablation were detected at distances greater than previously documented. These data suggest that intradiscal electrothermal therapy's proposed heat-dependent mechanisms of action are achievable in most discs. Among other factors, interspecimen variability of maximum temperatures may help explain the somewhat inconsistent clinical results following intradiscal electrothermal therapy.

Adult↗

PubMed2004

Assessment of pedicle screw placement utilizing conventional radiography and computed tomography: a proposed systematic approach to improve accuracy of interpretation.

STUDY DESIGN: This was a human cadaver study to determine the accuracy of conventional radiography and computed radiography in the evaluation of pedicle screw placement and to identify methodology for more precise reading of these examinations. OBJECTIVES: To determine the accuracy of conventional radiography and computed tomography in the evaluation of pedicle screw placement within lumbar vertebral pedicles and to develop methods to improve imaging interpretation. SUMMARY OF BACKGROUND DATA: Conventional radiography and computed tomography have been used in research and clinical settings to evaluate pedicle screw placement. This study evaluates the interpretative accuracy of readers blinded to the true position of screw placement using both imaging examinations. Furthermore, methodology was developed to improve accuracy of interpretation of these examinations. METHODS: Three cadaver lumbar spines were instrumented bilaterally with pedicle screws from L1 to L5. Thirty pedicles had 6.0 mm AO pedicle screws inserted using standard surgical technique. Seven directions of deliberate misplacement as well as correct placement of screws were performed at random levels for a total of eight possible screw positions. Conventional radiographs and computed tomography scans were obtained. A senior musculoskeletal radiologist and senior spine surgeon interpreted the images while blinded to screw placement. Examiners initially assessed the screws as in or out, followed by assessment of the eight possible types of screw position. Consensus interpretation was obtained regarding the placement of individual screws. The spines were then dissected to visualize the screws and their position related to the pedicle. After determining the true position of the screws, a systematic method was designed and applied to the interpretation of the imaging methods to identify screw positions. RESULTS: Using conventional radiographs, 63% of the screw placements were correctly identified as in or out of the pedicle. Computed tomography improved accuracy to 87%. Identifying the true directional component of screw position led to a decrease in accuracy (conventional radiographs 37% and computed tomography 47%). Using asystematic method to analyze imaging studies enabled detection of screw positions. CONCLUSION: Evaluation of pedicle screw placement is difficult even in experienced hands. A systematic approach to image interpretation should allow for an accurate assessment of pedicle screw placement.

Aged↗

PubMed2004

Two-year fusion rate equivalency between Grafton DBM gel and autograft in posterolateral spine fusion: a prospective controlled trial employing a side-by-side comparison in the same patient.

STUDY DESIGN: Multicenter, prospective equivalency trial with each patient serving as his/her own control. OBJECTIVES: To compare the effectiveness of a Grafton DBM gel composite with iliac crest autograft in posterolateral spine fusion. SUMMARY OF BACKGROUND DATA: While autograft remains the preferred graft material to facilitate spine fusion, the supply is limited and harvesting produces undesirable clinical consequences. METHODS: A total of 120 patients underwent posterolateral spine fusion with pedicle screw fixation and bone grafting. Iliac crest autograft was implanted on one side of the spine and a Grafton DBM/autograft composite was implanted on the contralateral side in the same patient. An independent, blinded reviewer evaluated anteroposterior and lateral flexion-extension radiographs. The fusion mass lateral to the instrumentation on each side was judged fused or not, and the mineralization of the graft was rated absent, mild, moderate, or extensive. The degree of correspondence in outcomes between sides was estimated by computing the percentage agreement and kappa statistic. RESULTS: Nearly 70% of patients (81 of 120) provided complete 24-month radiographic studies. The bone graft mass was fused in 42 cases (52%) on the Grafton DBMside and in 44 cases (54%) on the autograft side. The overall percentage agreement for fusion status between sides was approximately 75% (61 of 81), indicating moderately strong statistical correspondence (kappa = 0.51, P < 0.0001). Bone mineralization ratings also were similar between treated sides. Perfect agreement was realized in almost 60% of patients (48 of 81) with moderate statistical correspondence (weighted kappa = 0.54, P < 0.0001). CONCLUSIONS: Grafton DBM can extend a smaller quantity of autograft than is normally required to achieve a solid spinal arthrodesis. Consequently, a reduced amount of harvested autograft may be required, potentially diminishing the risk and severity of donor site complications.

Bone Matrix↗

PubMed2003

Biomechanical analysis of anterior instrumentation for lumbar corpectomy.

STUDY DESIGN: In vitro biomechanical assessment of spinal stability after corpectomy reconstruction. OBJECTIVES To gain a more thorough understanding of the biomechanical properties of anterior plate versus dual rod systems used for anterior lumbar corpectomy reconstruction. SUMMARY OF BACKGROUND DATA: Vertebral corpectomy is commonly required in the treatment of several types of spinal pathology (fracture, tumor, infection). Stabilization with strut allograft and anterior instrumentation can be accomplished with one of several anterior implant systems. These include plate systems and rod-based systems with theoretically different structural properties. METHODS: Two instrumentation systems, the ATL Z-plate and the Antares system, were each applied to 10 calf lumbar spines with a cortical strut graft reconstructing an L3 corpectomy defect. All spines were tested biomechanically to determine construct stiffness under physiologic loads in multiple planes and then tested in torsion to failure. RESULTS: There was greater stiffness (P < 0.05) in all directions of bending (flexion, extension, lateral bending) for the Antares dual rod construct compared to the Z-plate constructs. No significant difference was noted in either torsional testing under physiologic loads or torque to failure between the groups. CONCLUSIONS: Although there was significantly greater resistance to bending with the dual rod construct, the ultimate selection of a system will require an individual analysis of implant profile, construct demand, and ease of use. Both systems provided secure initial fixation following lumbar corpectomy; however, the Antares system may increase the likelihood of graft incorporation in cases with greater instability and higher load demands.

Animals↗

PubMed2003

Medical management of osteoporosis.

Osteoporosis is characterized by low-energy fractures resulting from inadequate bone mass and compromised microarchicture. Bone mass is maximized by adequate nutrition and calcium intake, normal menstrual cycles, and appropriate exercises. Low bone density, as determined by dual-energy x-ray absorptiometry, and high bone turnover, as characterized by elevated bone collagen breakdown products, are the primary indicators of bone fragility. Prevention and treatment of osteoporosis should emphasize adequate calcium and vitamin D intake and exercise. In addition, estrogen supplementation and selective estrogen receptor modulators (estrogen antagonists) can enhance bone mass and decrease the risk of spinal fractures, oral and intravenous bisphosphonates can significantly decrease the incidence of both spinal and hip fractures, and antiosteoporotic agents can help rebuild healthy bone.

Aged↗

PubMed1998

A placebo-controlled randomized clinical trial of nortriptyline for chronic low back pain.

To assess the efficacy of nortriptyline, a tricyclic antidepressant, as an analgesic in chronic back pain without depression, we conducted a randomized, double-blind, placebo-controlled, 8-week trial in 78 men recruited from primary care and general orthopedic settings, who had chronic low back pain (pain at T-6 or below on a daily basis for 6 months or longer). Of these 57 completed the trial; of the 21 who did not complete, four were withdrawn because of adverse effects. The intervention consisted of inert placebo or nortriptyline titrated to within the therapeutic range for treating major depression (50-150 ng/ml). The main outcome endpoints were pain (Descriptor Differential Scale), disability (Sickness Impact Profile), health-related quality of life (Quality of Well-Being Scale), mood (Beck Depression Inventory, Spielberger State Anxiety Inventory, Hamilton Anxiety/Depression Rating Scales), and physician rated outcome (Clinical Global Impression). Reduction in pain intensity scores was significantly greater for participants randomized to nortriptyline (difference in mean change 1.68, 95%-0.001, CI -3.36, P = 0.050), with a reduction of pain by 22% compared to 9% on placebo. Reduction in disability marginally favored nortriptyline (P = 0.055), but health-related quality of life, mood, and physician ratings of overall outcome did not differ significantly between treatments. Subgroup analyses of study completers supported the intent-to-treat analysis. Also, completers with radicular pain on nortriptyline (n = 5) had significantly (P < 0.05) better analgesia and overall outcome than did those on placebo (n = 6). The results suggest noradrenergic mechanisms are relevant to analgesia in back pain. This modest reduction in pain intensity suggests that physicians should carefully weigh the risks and benefits of nortriptyline in chronic back pain without depression.

Adult↗

PubMed1995

Psychosocial factors discriminate multidimensional clinical groups of chronic low back pain patients.

Previous studies have empirically defined clinical subgroups of chronic low back pain (CLBP) patients, based on differing patterns of pain, disability and emotional distress. Because these identified groups generally are comparable in terms of physical and demographic variables, variation in functional status cannot be adequately explained by medical or social factors. In the present study we evaluated whether other psychosocial factors (stress, coping attempts, and satisfaction with social supports) might differentiate the observed groups. A discriminate function analysis indicated that ratings of life adversity, coping, and social support statistically differentiate clinical groups of CLBP patients. Patients categorized as chronic pain syndrome (i.e., high levels of pain, disability and depression) reported greater life adversity, more reliance on passive/avoidant coping strategies, and less satisfaction with social support networks. Patients categorized as having good pain control (i.e., low levels of pain, disability and depression) reported less life adversity, less reliance on passive/avoidant coping strategies, and more satisfaction with social support networks. Finally, a mixed picture of less life adversity, but more reliance on passive/avoidant coping strategies and more satisfactory social support networks was reported by patients categorized in the positive adaptation to pain group (i.e., high levels of pain, but relatively low levels of disability and depression). These findings suggest that psychosocial factors may be important and complex correlates of multidimensional clinical presentations of CLBP. Psychosocial factors may also offer an avenue for intervention across 3 key dimensions of CLBP.

Adaptation, Psychological↗

PubMed1993

Coping activities in chronic low back pain: relationship with depression.

To help clarify the nature of coping activities in chronic pain, this study compared how depressed (n = 37) and non-depressed (n = 40) chronic low back pain (CLBP) patients attempted to cope with pain-specific and general non-pain life stressors, relative to matched healthy control subjects (n = 40). We hypothesized that depressed mood, rather than pain alone, would account for differences in coping activities between groups. Specifically, we expected that depressed CLBP patients would report a greater proportion of passive and avoidant coping responses and less active problem solving coping attempts than non-depressed patients and controls. Results indicated that depressed CLBP patients reported more passive-avoidant coping activities than did non-depressed CLBP patients and controls, whereas coping responses were similar for non-depressed CLBP patients and controls. Additionally, subjects across groups tended to report more passive-avoidant coping in response to the specific back pain stressor (i.e., exacerbation of back pain during activity) than to other life stressors. Finally, the magnitude of reported differences in coping attempts across groups varied as a function of the type of stressor (i.e., specific back pain stressor vs. general stressful life events), particularly with regard to a disinclination to seek social support in response to the back pain exacerbation. We conclude that: (1) chronic back pain patients may employ different coping activities when attempting to manage pain exacerbations than when confronting more general life stressors, and (2) an increased rate of passive-avoidant coping responses (relative to matched health controls) is associated with the combination of CLBP and concurrent depressed mood, rather than with CLBP alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Psychological↗