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.

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.

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.

Faking a profile: can naive subjects simulate whiplash responses?

The psychological symptom checklist, the SCL-90-R (Derogatis 1983), has been used to assess patients with a number of chronic pain syndromes. For whiplash injury, a characteristic profile has been found (Wallis et al. 1995). However, there is still a belief that patients with neck pain following whiplash injury may be malingering, and therefore the utility of the SCL-90-R as a screen for possible malingering is assessed here. Forty pain-free university students were asked to simulate chronic pain 6 months after a motor vehicle accident in order to ensure compensation. The SCL-90-R, McGill Pain Questionnaire and a visual analogue pain scale were used. Students' scores were compared with those of a group of 132 whiplash patients (Wallis et al. 1995). Differences between the two groups were striking; the students scored significantly higher than patients on all subscales of the SCL-90-R and on the visual analogue pain scale (Mann-Whitney P-values all less than 0.001). However, pain scores for both groups on the McGill Pain Questionnaire were similar. The conclusion was that it is very difficult for an ingenuine individual to fake a psychological profile typical of a whiplash patient.

Resolution of psychological distress of whiplash patients following treatment by radiofrequency neurotomy: a randomised, double-blind, placebo-controlled trial.

It is well recognised that patients with chronic pain, in particular, chronic whiplash-associated neck pain, exhibit psychological distress. However, debate continues as to whether the psychological distress precedes and causes the chronic pain or, conversely, the psychological distress is a consequence of chronic pain. Using cervical zygapophysial joint pain as a model for chronic pain, the effect of a definitive neurosurgical treatment on the associated psychological distress was studied. Seventeen patients with a single painful cervical zygapophysial joint participated in a randomised, double-blind, placebo-controlled trial of percutaneous radiofrequency neurotomy. Their pain and psychological status were evaluated pre-operatively and 3 months post-operatively by medical interview and examination, a visual analogue pain scale, the McGill Pain Questionnaire, and the SCL-90-R psychological questionnaire. All patients who obtained complete pain relief exhibited resolution of their pre-operative psychological distress. In contrast, all but one of the patients whose pain remained unrelieved continued to suffer psychological distress. Because psychological distress resolved following a neurosurgical treatment which completely relieved pain, without psychological co-therapy, it is concluded that the psychological distress exhibited by these patients was a consequence of the chronic somatic pain.

The false-positive rate of uncontrolled diagnostic blocks of the lumbar zygapophysial joints.

One hundred and seventy-six consecutive patients with chronic low back pain and no history of previous lumbar surgery were studied to determine the false-positive rate of single diagnostic blocks of the lumbar zygapophysial joints. All patients underwent diagnostic blocks using lignocaine. Those patients who obtained definite or complete relief from these blocks subsequently underwent confirmatory blocks using bupivacaine. Eighty-three patients (47%) had a definite or greater response to the initial, lignocaine injection at one or more levels but only 26 (15%) had a 50% or greater response to a confirmatory injection of 0.5% bupivacaine. Using the response to confirmatory blocks as the criterion standard, the false-positive rate of uncontrolled diagnostic blocks was 38% and the positive predictive value of these blocks was only 31%. Because the positive predictive value of a test is lower when the pre-test probability (prevalence) is low, and because the prevalence of lumbar zygapophysial joint pain is likely to be less than 50%, uncontrolled diagnostic blocks will always be associated with an unacceptably low positive predictive value. These features render uncontrolled diagnostic blocks unreliable for the diagnosis of lumbar zygapophysial joint pain not only in epidemiologic studies but also in any given patient.

Low pharmacological responsiveness of the vertebro-basilar circulation in Macaca nemestrina monkeys.

We have examined the responsiveness of the vertebro-basilar circulation of the anesthetized Macaca nemestrina monkey to vasoactive agents infused directly into the artery. Infusion of noradrenaline caused a slight increase in vertebral arterial resistance. This constriction was less than that seen in previous experiments with either the internal or vertebral arterial resistance. This constriction was less than that seen in previous experiments with either the internal or external carotid arteries. In the presence of vasodilatation caused by inhalation of a CO2-rich gas mixture, this constriction became a dilatation. Serotonin was without significant effect on the vertebral arterial bed. Bradykinin, histamine and prostaglandin E1 all produced slight dilatation, with bradykinin being the most potent. In all cases the concentration required to produce an effect on the vasculature was much greater in the vertebral circulation than it is in the internal carotid and extracerebral circulations. We conclude that the intact vertebro-basilar circulation is much less sensitive to vasoactive agents than experiments with isolated segments of these arteries would indicate and that therefore these agents are unlikely to play a significant part in the pathogenesis of vertebro-basilar migraine.

Technical limitations to the efficacy of radiofrequency neurotomy for spinal pain.

Prompted by clinical failures of percutaneous radiofrequency neurotomy in the treatment of back pain and neck pain, we performed a study to determine the shape and size of lesions made by radiofrequency electrodes. Experimental lesions were made in egg white and fresh meat at temperatures recommended in clinical practice. The cardinal finding was that lesions do not extend distal to the tip of the electrode. They only extend radially around the electrode tip in the shape of an oblate spheroid, with a maximal effective radius of only 2 mm. Consequently, if electrodes are directed perpendicularly onto a nerve, the nerve may not be encompassed by the lesion generated. Some of the clinical failures of percutaneous medial branch neurotomy ("facet rhizotomy") may be due to this phenomenon. We suggest modified techniques for medial branch neurotomy in which the electrodes are introduced parallel to the target nerve whereupon it is more readily encompassed by the radial spread of the lesion.

Percutaneous radiofrequency neurotomy in the treatment of cervical zygapophysial joint pain: a caution.

Percutaneous radiofrequency neurotomy has been used in the treatment of pain from the cervical zygapophysial joints, but the results have been modest and not compelling. Several factors might account for its apparent poor success rate, including inadequate patient selection, inaccurate surgical anatomy, and technical errors. In an effort to overcome these confounders, we used comparative local anesthetic blocks to preoperatively, definitively diagnose cervical zygapophysial joint pain and developed an amended operative technique based on formal anatomical studies. An audit was conducted of our experience with 19 patients to determine whether there was sufficient merit in the amended procedure to justify a randomized, double-blind, controlled trial. The duration of complete pain relief was the principal outcome measure. Side effects and complications were also monitored. Of the 10 patients who underwent third occipital neurotomy for the treatment of C2-C3 zygapophysial joint pain, only 4 obtained long-lasting relief. The other six patients reported an early return of their pain and constituted technical failures; the third occipital nerve was inadequately coagulated and recovered in the immediate postoperative period. Of the 10 patients who underwent lower cervical medial branch neurotomy, 7 obtained complete pain relief for clinically useful periods and were able to resume their activities of daily living and employment. After procedures at all levels, a brief period of postoperative pain was experienced by the patients and ataxia was a side effect of third occipital neurotomy. There were no cases of postoperative infection or anesthesia dolorosa. Given the high technical failure rate of third occipital neurotomy, we recommend that this procedure be abandoned until the technical problems can be overcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term follow-up of patients treated with cervical radiofrequency neurotomy for chronic neck pain.

OBJECTIVE: To determine the long-term efficacy of percutaneous radiofrequency medial branch neurotomy in the treatment of chronic neck pain. METHODS: Between 1991 and 1996, radiofrequency neurotomy was performed in 28 patients diagnosed as having cervical zygapophysial joint pain on the basis of controlled diagnostic blocks. The procedure was repeated in patients whose pain recurred. Outcome measures were the proportion of patients who responded to the initial procedure and the duration of relief subsequently obtained. Outcome was correlated with the operator performing the procedure, the type of electrode used, litigation status, and the type of diagnostic blocks used to establish the diagnosis. RESULTS: Complete relief of pain was obtained in 71% of patients after an initial procedure. No patient who failed to respond to a first procedure responded to a repeat procedure, but if pain returned after a successful initial procedure, relief could be reinstated by a repeat procedure. The median duration of relief after a first procedure was 219 days when failures are included but 422 days when only successful cases are considered. The median duration of relief after repeat procedures was at least 219 days; several patients had ongoing relief at the time of follow-up. Outcome did not differ according to the operator, the type of electrode used, litigation status, or the type of diagnostic block used. CONCLUSION: Radiofrequency neurotomy provides clinically significant and satisfying periods of freedom from pain, and its effects can be reinstated if pain recurs.

The anatomy of the so-called "articular nerves" and their relationship to facet denervation in the treatment of low-back pain.

Disections of the dorsal rami of L1--5 were performed in human cadavers, and the course of the dorsal rami, their branches, and the innervation of the zygapophyseal joints in the lumbar region were specifically studied. At the L-1 through L-4 levels, the dorsal rami divide into medial and lateral branches within the intertransverse ligaments. Each medial branch runs across the root of the adjacent superior articular process. At the caudal edge of the process, the branch turns medially beneath the mammillo-accessory ligament. Beneath the mammillo-accessory ligament, medial branches occur that innervate the adjacent zygapophyseal joint, and distal zygapophyseal branches arise at the laminar level to innervate the next lower joint. The L-5 dorsal ramus runs along a groove between the ala of the sacrum and its superior articular process. A the caudal edge of the articular process, the ramus divides into medial and lateral branches, and the medial branch supplies the L5--S1 articulation.

Decreased carotid arterial resistance in cats in response to trigeminal stimulation.

Stimulation of the trigeminal nerve or ganglion in the cat caused a frequency-dependent reduction in carotid vascular resistance. Systemic arterial blood pressure (SABP) decreased at low frequencies (0.2 to 5 sec-1) and increased at higher frequencies, thus increasing carotid blood flow at the higher frequencies. The effect on resistance was predominantly ipsilateral and was unaltered by cervical sympathectomy, but was abolished or substantially reduced by section of the trigeminal root proximal to the ganglion. Diminution of carotid vascular resistance was replicated by stimulation of the greater superficial petrosal (GSP) nerve without any change in SABP. Section of the seventh cranial nerve reduced or abolished the response to stimulation of the trigeminal nerve but not that from the GSP nerve. The trigeminal response was prevented by ganglion-blocking drugs in seven out of eight cats. The resistance response was unaffected by noradrenergic, cholinergic, serotonergic, and histamine-2 blocking agents. No neural connection could be demonstrated between the GSP and the trigeminal ganglion, and the vascular response to GSP stimulation persisted after trigeminal section. It is concluded that activation of the trigeminal system increases carotid blood flow by a pathway involving the seventh cranial nerve, the GSP and Vidian nerves, and a parasympathetic synapse employing an unconventional transmitter. A varying proportion of the response (greatest in the third division) may be mediated by antidromic activation of trigeminal nerves. These findings may have clinical implications for the vascular changes of migraine and other facial pain.

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.

The utility of comparative local anesthetic blocks versus placebo-controlled blocks for the diagnosis of cervical zygapophysial joint pain.

BACKGROUND: The development of target-specific local anesthetic blocks has enabled pain physicians to explore the anatomical source of chronic spinal pain. However, such blocks rely on subjective responses and may be subject to the placebo effect. Comparative local anesthetic blocks have been advocated as a means of identifying true-positive cases and excluding placebo responders. This paradigm employs two local anesthetics with different durations of action; only patients who obtain reproducible relief and correctly identify the longer-acting agent are considered positive. OBJECTIVE: Our objective was to evaluate the reliability of comparative blocks of the medial branches of the cervical dorsal rami in the diagnosis of cervical zygapophysial joint pain. DESIGN: We compared comparative blocks and the criterion-standard of randomized, double-blind, placebo-controlled blocks. SETTING: The study was conducted at a tertiary referral center. PATIENTS: We studied the first 50 consecutive patients referred for assessment of chronic neck pain (> 3 months' duration) after a motor vehicle accident, who completed a series of placebo-controlled blocks after an initial positive response. Patients were 41 +/- 11 years (mean +/- SD) old with a male/female ratio of 1:2. METHODS: Patients underwent three blocks using three different agents-lignocaine, bupivacaine, and normal saline--administered on separate occasions, in random order and under double-blind conditions. The diagnostic decision based on comparative blocks alone was compared with that based on placebo-controlled blocks. RESULTS: Comparative blocks were found to have a specificity of 88%, but only marginal sensitivity (54%). Although comparative blocks result in few false-positive diagnoses, their liability is that they result in a high proportion of false-negative diagnoses. Expanding the comparative blocks diagnostic criteria to include all patients with reproducible relief, irrespective of duration, increases sensitivity to 100% but lowers specificity to 65%. CONCLUSIONS: Whether physicians use comparative or placebo-controlled blocks depends upon the implications of their results. If innocuous therapy will be prescribed, comparative blocks might suffice. However, when diagnostic certainty is critical, such as in a medicolegal context or when surgical intervention is contemplated, placebo-controlled blocks are recommended.

False-positive rates of cervical zygapophysial joint blocks.

OBJECTIVE: To determine the false-positive rate of anesthetic blocks of the medial branches of the cervical dorsal rami in the diagnosis of cervical zygapophysial joint pain. DESIGN: Comparison between single diagnostic blocks, and a criterion standard of double-blind, controlled, differential anesthetic blocks. SETTING: Tertiary referral center. PATIENTS: The first 55 consecutive patients with neck pain for > 3 months after and attributable to a motor vehicle accident, and who had completed a second diagnostic block after an initial positive response. A total of 60 joints was studied, with five patients providing two joints each. The mean age was 41 years; 61% were female. METHODS: Each patient had been investigated with radiologically controlled blocks of the medial branches of the cervical dorsal rami to anesthetize the target cervical zygapophysial joint. The initial block was performed using either 0.5% bupivacaine or 2% lignocaine, randomly selected. The duration of pain relief was assessed in a double-blind fashion. The procedure was repeated with the complementary anesthetic. Only patients experiencing a longer period of pain relief from bupivacaine were considered to have true-positive responses. RESULTS: The second block failed to relieve pain in two of the tested joints. In a further 14 joints, the control blocks relieved pain, but the patient failed to correctly discriminate the longer acting anesthetic. The remaining 44 joints met the criteria for true-positive responses. The false-positive rate of single blocks was 16 of 60 or 27% (95% confidence interval 15%, 38%). CONCLUSIONS: Uncontrolled diagnostic blocks are compromised by a significant false-positive rate that seriously detracts from the specificity of the test.

The value of the provocation response in lumbar zygapophyseal joint injections.

OBJECTIVE: To determine the relationship between pain provocation and the analgesic response in lumbar zygapophyseal joint blocks. DESIGN: Consecutive patients undergoing intraarticular zygapophyseal joint blocks for the investigation of low back pain were included in this prospective study. SETTING: The referred sample was from the metropolitan areas of New Orleans and San Francisco. PATIENTS: Ninety patients with low back pain of > 3 months' duration and no history of lumbar surgery. INTERVENTIONS: All patients underwent one or more intraarticular injections of radiographic contrast followed by lignocaine (lidocaine) 2% into zygapophyseal joints between L2-3 and L5-S1. Those with definite responses at one or more levels underwent confirmatory blocks using 0.5% bupivacaine. OUTCOME MEASURES: Provocation of familiar pain and relief of pain after the injection of local anesthetic. Patients were assessed by an independent observer. RESULTS: A total of 203 joints were studied. Adopting liberal criteria, either exact or similar reproduction of pain on the one hand correlated with either definite or complete relief of pain after a single, analgesic block on the other (p < 0.0001). However, when more stringent criteria were adopted, such as response to a confirmatory block using bupivacaine, there was no significant association. CONCLUSIONS: This study calls into question the validity of pain provocation alone as a criterion standard in patients undergoing diagnostic lumbar zygapophyseal joint blocks.

Anatomy and physiology of headache.

Headache is a vast field with many different varieties of headaches and classifications. However, all headaches have a common anatomy and physiology. All headaches are mediated by the trigeminocervical nucleus, and are initiated by noxious stimulation of the endings of the nerves that synapse on this nucleus, by irritation of the nerves themselves, or by disinhibition of the nucleus. A mastery of the relevant anatomy and physiology of the trigeminocervical nociceptive system serves to predict and summarise the many varieties of headache systematically and with reference to their mechanisms.

Modelling the muscles of the scapula morphometric and coordinate data and functional implications.

Modelling of the shoulder mechanism is dependent upon reliable data on the morphometry and points of attachment of the relevant muscles. In this paper, the authors present coordinate data which have been derived from the radiography of dissected cadavers. All of the coordinates have been normalised with respect to reference dimensions of the relevant segments (humerus, scapula, clavicle and trunk). Similarly the measurements of physiological cross-section area (PCSA) have been normalised with respect to that of deltoid. The measurements of PCSA have been shown to agree largely with the work of Veeger et al. [J. Biomechanics 24, 615-629 (1991)] and Karlsson and Peterson [J. Biomechanics 25, 189-199 (1992)]. While the majority of the descriptions of morphometry concur with accepted texts there are some notable disagreements, particularly concerning trapezius.

High-intensity zone: a diagnostic sign of painful lumbar disc on magnetic resonance imaging.

The prevalence, validity and reliability of high-intensity zones in the annulus fibrosus seen on T2-weighted magnetic resonance images of patients with intractable low-back pain were determined. This sign was readily recognized by two independent observers. It occurred in 28% of 500 patients undergoing magnetic resonance imaging for back pain. The presence of a high-intensity zone correlated significantly with the presence of Grade 4 annular disruption and with reproduction of the patient's pain. Its sensitivity as a sign of either annular disruption or pain was modest but its specificity was high, and its positive predictive value for a severely disrupted, symptomatic disc was 86%. This sign is diagnostic of painful internal disc disruption.

Epidural steroids.

Although perhaps only controversial internationally, epidural steroids have become the focus of litigation in Australia. The literature provides endorsement but offers little compelling data on rationale and efficacy. Steroid preparations appear to be chemically safe, provided they are accurately injected into the epidural space. Hazards occur if intrathecal penetration is not recognized. Conventional techniques do not guarantee that injectates reach the desired target nerve.