A retrospective analysis of chronic subdural haematoma recurrence rates following burr hole trephination versus minicraniotomy.

The aim of this study was to determine the subdural haematoma recurrence rate in patients with symptomatic chronic subdural haematomas (CSDH) treated with either burr hole trephination (BHT) or minicraniotomy (MC) and to determine whether a statistically significant difference exists between the two techniques. A retrospective analysis of all consecutive patients with symptomatic CSDH treated with BHT or MC at the John Hunter Hospital Neurosurgery Department between July 2004 and July 2016 was performed. After inclusion/exclusion criteria were applied, 368 patients with 439 CSDHs were eligible. Baseline demographic data was recorded for all patients. Statistical analysis was performed assessing haematoma recurrence as the primary outcome and mortality as a secondary outcome. Three hundred and sixty eight patients were included in the study, with 225 being treated with MC and 143 with BHT. Baseline demographic data was similar between the two groups. The recurrence rate for patients treated with BHT was 0.13 (95% CI 0.08-0.18), versus 0.18 (95% CI 0.13-0.23) in the MC group. This difference was not statistically significant. Similarly, there was no statistically significant difference in mortality rates between the two groups. The mortality rate in the BHT group was 0.09 (95% CI 0.05-0.14) versus 0.09 (95% CI 0.05-0.13) in the MC group. In our series there was no difference in recurrence rates or mortality rates between the two groups, suggesting MC is an effective alternative to BHT in the management of symptomatic CSDH.

Evidence of effectiveness of a fracture liaison service to reduce the re-fracture rate.

SUMMARY: We assessed the ability of a fracture liaison service (FLS) to directly reduce re-fracture risk. Having a FLS is associated with a ∼40% reduction in the 3-year risk of major bone and ∼30% of any bone re-fracture. The number needed to treat to prevent a re-fracture is 20. INTRODUCTION: FLS have been promoted as the most effective interventions for secondary fracture prevention, and while there is evidence of increased rate of investigation and treatment at institutions with a FLS, only a few studies have considered fracture outcomes directly. We therefore sought to evaluate the ability of our FLS to reduce re-fracture risk. METHODS: Historical cohort study of all patients ≥50 years presenting over a 6-month period with a minimal trauma fracture (MTF) to the emergency departments of a tertiary hospital with a FLS, and one without a FLS. Baseline characteristics, mortality and MTFs over a 3-year follow-up were recorded. RESULTS: Five hundred fifteen patients at the FLS hospital and 416 patients at the non-FLS hospital were studied. Over 3 years, 63/515 (12%) patients at the FLS hospital and 70/416 (17%) at the non-FLS hospital had a MTF. All patients were analysed in an intention-to-treat analysis regardless of whether they were seen in the FLS follow-up clinic. Statistical analysis using Cox proportional hazard models in the presence of a competing risk of death from any cause was used. After adjustment for baseline characteristics, there was a ∼30% reduction in rate of any re-fracture at the FLS hospital (hazard ratio (HR) 0.67, confidence interval (CI) 0.47-0.95, p value 0.025) and a ∼40% reduction in major re-fractures (hip, spine, femur, pelvis or humerus) (HR 0.59, CI 0.39-0.90, p value 0.013). CONCLUSIONS: We found a ∼30% reduction in any re-fractures and a ∼40% reduction in major re-fractures at the FLS hospital compared with a similar non-FLS hospital. The number of patients needed to treat to prevent one new fracture over 3 years is 20.

The pathophysiology of disc degeneration: a critical review.

The pathophysiology of intervertebral disc degeneration has been extensively studied. Various factors have been suggested as influencing its aetiology, including mechanical factors, such as compressive loading, shear stress and vibration, as well as ageing, genetic, systemic and toxic factors, which can lead to degeneration of the disc through biochemical reactions. How are these factors linked? What is their individual importance? There is no clear evidence indicating whether ageing in the presence of repetitive injury or repetitive injury in the absence of ageing plays a greater role in the degenerative process. Mechanical factors can trigger biochemical reactions which, in turn, may promote the normal biological changes of ageing, which can also be accelerated by genetic factors. Degradation of the molecular structure of the disc during ageing renders it more susceptible to superimposed mechanical injuries. This review supports the theory that degeneration of the disc has a complex multifactorial aetiology. Which factors initiate the events in the degenerative cascade is a question that remains unanswered, but most evidence points to an age-related process influenced primarily by mechanical and genetic factors.

Anatomy and biomechanics of quadratus lumborum.

Various actions on the lumbar spine have been attributed to quadratus lumborum, but they have not been substantiated by quantitative data. The present study was undertaken to determine the magnitude of forces and moments that quadratus lumborum could exert on the lumbar spine. The fascicular anatomy of quadratus lumborum was studied in six embalmed cadavers. For each fascicle, the sites of attachment, orientation, and physiological cross-sectional area were determined. The fascicular anatomy varied considerably, between sides and between specimens, with respect to the number of fascicles, their prevalence, and their sizes. Approximately half of the fascicles act on the twelfth rib, and the rest act on the lumbar spine. The more consistently present fascicles were incorporated, as force-equivalents, into a model of quadratus lumborum in order to determine its possible actions. The magnitudes of the compression forces exerted by quadratus lumborum on the lumbar spine, the extensor moment, and the lateral bending moment, were each no greater than 10 per cent of those exerted by erector spinae and multifidus. These data indicate that quadratus lumborum has no more than a modest action on the lumbar spine, in quantitative terms. Its actual role in spinal biomechanics has still to be determined.

Systematic review of tests to identify the disc, SIJ or facet joint as the source of low back pain.

Clinical practice guidelines state that the tissue source of low back pain cannot be specified in the majority of patients. However, there has been no systematic review of the accuracy of diagnostic tests used to identify the source of low back pain. The aim of this systematic review was therefore to determine the diagnostic accuracy of tests available to clinicians to identify the disc, facet joint or sacroiliac joint (SIJ) as the source of low back pain. MEDLINE, EMBASE and CINAHL were searched up to February 2006 with citation tracking of eligible studies. Eligible studies compared index tests with an appropriate reference test (discography, facet joint or SIJ blocks or medial branch blocks) in patients with low back pain. Positive likelihood ratios (+LR) > 2 or negative likelihood ratios (-LR) < 0.5 were considered informative. Forty-one studies of moderate quality were included; 28 investigated the disc, 8 the facet joint and 7 the SIJ. Various features observed on MRI (high intensity zone, endplate changes and disc degeneration) produced informative +LR (> 2) in the majority of studies increasing the probability of the disc being the low back pain source. However, heterogeneity of the data prevented pooling. +LR ranged from 1.5 to 5.9, 1.6 to 4.0, and 0.6 to 5.9 for high intensity zone, disc degeneration and endplate changes, respectively. Centralisation was the only clinical feature found to increase the likelihood of the disc as the source of pain: +LR = 2.8 (95%CI 1.4-5.3). Absence of degeneration on MRI was the only test found to reduce the likelihood of the disc as the source of pain: -LR = 0.21 (95%CI 0.12-0.35). While single manual tests of the SIJ were uninformative, their use in combination was informative with +LR of 3.2 (95%CI 2.3-4.4) and -LR of 0.29 (95%CI 0.12-0.35). None of the tests for facet joint pain were found to be informative. The results of this review demonstrate that tests do exist that change the probability of the disc or SIJ (but not the facet joint) as the source of low back pain. However, the changes in probability are usually small and at best moderate. The usefulness of these tests in clinical practice, particularly for guiding treatment selection, remains unclear.

Radiofrequency neurotomy for the treatment of third occipital headache.

OBJECTIVE: To evaluate the efficacy of a revised technique of percutaneous radiofrequency neurotomy for third occipital headache. METHODS: The revisions included using a large gauge electrode, ensuring minimum separation between the three electrode placements, and holding the electrode in place by hand. The revised technique was used to treat 51 nerves in 49 patients diagnosed as suffering from third occipital headache on the basis of controlled diagnostic blocks of the third occipital nerve. The criteria for successful outcome were complete relief of pain for at least 90 days associated with restoration of normal activities of daily living, and no use of drug treatment for the headache. RESULTS: Of the 49 patients, 43 (88%) achieved a successful outcome. The median duration of relief in these patients was 297 days, with eight patients continuing to have ongoing relief. Fourteen patients underwent a repeat neurotomy to reinstate relief, with 12 (86%) achieving a successful outcome. The median duration of relief in these patients was 217 days, with six patients having ongoing relief. Side effects of the procedure were consistent with coagulation of the third occipital nerve and consisted of slight ataxia, numbness, and temporary dysaesthesia. No side effects required intervention, and they were tolerated by the patients in exchange for the relief of headache. CONCLUSIONS: Use of the revised procedure greatly improved the rather low success rate previously encountered with third occipital neurotomy. Although the relief of headache is limited in duration, it is profound and can be reinstated by repeat neurotomy. No other form of treatment has been validated for this common form of headache.

Occipital headaches stemming from the lateral atlanto-axial (C1-2) joint.

Studies in normal volunteers have demonstrated that the lateral atlanto-axial joints (C1-2) are capable of causing pain in the occiput, but few clinical studies have validated this source of occipital headache. The present study tested the null hypothesis that the lateral atlanto-axial joints are not a common source of occipital headache. Patients presenting with occipital pain underwent diagnostic blocks of their lateral atlanto-axial joints if they demonstrated clinical features presumptively suggestive of a C1-2 origin for their pain. Of 34 patients investigated, 21 obtained complete relief of their headache following diagnostic blocks, indicating that a C1-2 source of occipital pain is not rare. The clinical features used to select patients for blocks, however, had a positive predictive value of only 60%. Further study of headaches from C1-2 seems justified in order to establish more definitively the prevalence of this condition and how it might become better recognized in practice.

Safety, efficacy, and cost effectiveness of evidence-based guidelines for the management of acute low back pain in primary care.

STUDY DESIGN: A case-control study involving parallel benchmarking audits was conducted. OBJECTIVE: To compare the safety, efficacy, and cost effectiveness of evidence-based medical care and usual care for acute low back pain. SUMMARY OF BACKGROUND DATA: Although several sets of guidelines have been promoted for the management of acute low back pain, there is no evidence that following guidelines results in better outcomes. METHODS: Special clinics were established, at which trained medical practitioners managed patients with acute low back pain according to evidence-based guidelines. Their outcomes were audited by independent research nurses. Meanwhile, and separately, the outcomes of patients managed by their own general practitioners were audited by research nurses using the same instruments of assessment. RESULTS: In both settings, patients showed remarkable degrees and rates of recovery, with low rates of recurrence. However, evidence-based medical care resulted in a significantly lower cost of treatment; a significantly greater reduction in pain, sustained at both 6 and 12 months; significantly fewer patients requiring continuing care at 3, 6, and 12 months; a significantly greater proportion of patients fully recovered at 12 months; and significantly greater proportions of patients rating their treatment as extremely helpful and offering positive, unsolicited comments about their treatment. CONCLUSIONS: The immediate results from evidence-based care are marginally better than those from good usual care, but in the long term, evidence-based care achieves clinically and statistically significant gains, with fewer patients requiring continuing care and remaining in pain. Consumers approve of evidence-based care.

Cervicogenic headache: anatomic basis and pathophysiologic mechanisms.

Cervicogenic headache is pain perceived in the head but referred from a primary source in the cervical spine. The physiologic basis for this pain is convergence between trigeminal afferents and afferents from the upper three cervical spinal nerves. The possible sources of cervicogenic headache lie in the structures innervated by the C1 to C3 spinal nerves, and include the upper cervical synovial joints, the upper cervical muscles, the C2-3 disc, the vertebral and internal carotid arteries, and the dura mater of the upper spinal cord and posterior cranial fossa. Experiments in normal volunteers have established that the cervical muscles and joints can be sources of headache.

Biomechanics of the cervical spine Part 3: minor injuries.

Minor injuries of the cervical spine are essentially defined as injuries that do not involve a fracture. Archetypical of minor cervical injury is the whiplash injury. Among other reasons, neck pain after whiplash has been controversial because critics do not credit that an injury to the neck can occur in a whiplash accident. In pursuit of the injury mechanism, bioengineers have used mathematical modelling, cadaver studies, and human volunteers to study the kinematics of the neck under the conditions of whiplash. Particularly illuminating have been cinephotographic and cineradiographic studies of cadavers and of normal volunteers. They demonstrate that externally, the head and neck do not exceed normal physiological limits. However, the cervical spine undergoes a sigmoid deformation very early after impact. During this deformation, lower cervical segments undergo posterior rotation around an abnormally high axis of rotation, resulting in abnormal separation of the anterior elements of the cervical spine, and impaction of the zygapophysial joints. The demonstration of a mechanism for injury of the zygapophysial joints complements postmortem studies that reveal lesions in these joints, and clinical studies that have demonstrated that zygapophysial joint pain is the single most common basis for chronic neck pain after injury.

Pharmacologic pain treatment of musculoskeletal disorders: current perspectives and future prospects.

OBJECTIVE: The authors aimed to provide an educational update on the current evidence of the effectiveness of drug therapy in the treatment of musculoskeletal pain and to offer a perspective of possible future developments. DESIGN: The authors used a pragmatic review of data provided by available systematic reviews and seminal controlled studies pertaining to the treatment of regional musculoskeletal pain problems. RESULTS: Epidural steroids may offer limited, short-term benefit for sciatica. Local injections of steroids are either ineffective or provide short-lasting benefits. Nonsteroidal anti-inflammatory drugs and opioids reduce pain, but the effect size is modest. The literature does not support convincingly the use of antidepressants. Certain muscle relaxants may be useful in the treatment of back pain. Hyaluronic acid, neutraceutical agents, avocado-soybean unsaponifiable agents, oxaceprol and diacerein may be effective in the treatment of osteoarthritis, but the information regarding these new agents does not allow wholesale endorsement of these substances. Selective epidural injection of steroids at a target nerve root approached through the intervertebral foramin has the potential to replace the traditional epidural approach. Long-acting, C--fiber-specific local anesthetics are under investigation and could provide long-lasting pain relief without motor or sensory impairment. In the future, central hypersensitivity in chronic musculoskeletal pain might be treated using antagonists of the N-methyl-D-aspartate receptor. Cannabinoid agents produce antinociception and prevent experimentally induced hyperalgesia in animals, and they may find a role in pain management. Methods to optimize drug combinations are available. CONCLUSIONS: The effectiveness of the currently available drugs in the treatment of musculoskeletal pain conditions is disappointing. Recent developments may open new perspectives in this area of pain medicine.

Joints of the cervical vertebral column.

The developing understanding of the morphology of the cervical spine has revealed the complexity of the system. A review of selected literature reported that a number of the joints have an unusual nature and exhibit complicated and even paradoxical motions. For the practicing therapist, the significance of these observations is that assessment and treatment procedures of the cervical spine must be very carefully analyzed. There are significant differing behaviors of some of the cervical joints in response to small changes in movement patterns or initial positioning. Therefore it is not possible to broadly classify results of assessment procedures as normal or pathological without a clear and detailed understanding of the underlying morphology.

Complex regional pain syndrome.

Despite its recommendation by the International Association for the Study of Pain, the term 'complex regional pain syndrome' has not been widely adopted. Most authors still prefer the term 'reflex sympathetic dystrophy'. The diagnostic criteria recommended by the International Association for the Study of Pain have been criticized as lacking specificity, and refined criteria have been proposed. The pathophysiology of the complex regional pain syndrome remains elusive, but most recent work favours a central mechanism both for the sensory features and the autonomic features. Peripheral mechanisms include tissue acidosis. Some investigators, however, view the condition as psycho-neurogenic. Although recommended by some, laboratory tests add little to diagnostic confidence. Certain prophylactic measures have been recommended for patients undergoing surgery, and for the treatment of fractures of the radius. Treatment is still based largely on traditional wisdom. Some new treatments have been promoted on the basis of uncontrolled studies. Controlled studies have indicated possible roles for bisphosphonates and spinal cord stimulation.

Twelve-month follow-up of a controlled trial of intradiscal thermal anuloplasty for back pain due to internal disc disruption.

STUDY DESIGN: Case-control study. OBJECTIVES: To determine the prima facie efficacy of intradiscal electrothermal anuloplasty (IDTA). SUMMARY OF BACKGROUND DATA: Although it is being used increasingly as a putative treatment for internal disc disruption, no studies have been published on the efficacy of IDTA. METHODS: Fifty-three patients with back pain determined by computed tomographic (CT)-discography to be due to internal disc disruption were offered treatment. The outcomes of 35 patients treated with IDTA were compared with those of a convenience sample of 17 patients treated with a physical rehabilitation program, by using a visual analog pain scale, use of analgesics, and return to work as measures. RESULTS: At 3 months, only one control patient obtained any significant degree of relief of pain, compared with 23 in the index group. Relief of pain was sustained at 6 and 12 months and was associated with improvement in disability, reduced drug use, and a return to work rate of 53%. Depending on the stringency of criteria used, the success rate of IDTA may be as low as 23% or as high as 60% with confidence intervals of +/-16%. CONCLUSIONS: In carefully selected cases, IDTA can eliminate or dramatically reduce the pain of internal disc disruption in a substantial proportion of patients and appears to be superior to conventional conservative care for internal disc disruption.

Biomechanics of the cervical spine. I: Normal kinematics.

UNLABELLED: This review constitutes the first of four reviews that systematically address contemporary knowledge about the mechanical behavior of the cervical vertebrae and the soft-tissues of the cervical spine, under normal conditions and under conditions that result in minor or major injuries. This first review considers the normal kinematics of the cervical spine, which predicates the appreciation of the biomechanics of cervical spine injury. It summarizes the cardinal anatomical features of the cervical spine that determine how the cervical vertebrae and their joints behave. The results are collated of multiple studies that have measured the range of motion of individual joints of the cervical spine. However, modern studies are highlighted that reveal that, even under normal conditions, range of motion is not consistent either in time or according to the direction of motion. As well, detailed studies are summarized that reveal the order of movement of individual vertebrae as the cervical spine flexes or extends. The review concludes with an account of the location of instantaneous centres of rotation and their biological basis. RELEVANCE: The fact and precepts covered in this review underlie many observations that are critical to comprehending how the cervical spine behaves under adverse conditions, and how it might be injured. Forthcoming reviews draw on this information to explain how injuries might occur in situations where hitherto it was believed that no injury was possible, or that no evidence of injury could be detected.