Introduction

Early intervention is advocated to prevent long-term work absence due to musculoskeletal (MSK) pain. The SWAP trial tested whether adding a vocational advice (VA) service to best current care led to fewer days work absence over 4 months.

The issues surrounding raised levels of metal ions in the blood following large head metal-on-metal total hip replacement (THR), such as cobalt and chromium, have been well documented. Despite the national popularity of uncemented metal-on-polyethylene (MoP) THR using a large-diameter femoral head, few papers have reported the levels of metal ions in the blood following this combination. Following an isolated failure of a 44 mm Trident–Accolade uncemented THR associated with severe wear between the femoral head and the trunnion in the presence of markedly elevated levels of cobalt ions in the blood, we investigated the relationship between modular femoral head diameter and the levels of cobalt and chromium ions in the blood following this THR.

A total of 69 patients received an uncemented Trident–Accolade MoP THR in 2009. Of these, 43 patients (23 men and 20 women, mean age 67.0 years) were recruited and had levels of cobalt and chromium ions in the blood measured between May and June 2012. The patients were then divided into three groups according to the diameter of the femoral head used: 12 patients in the 28 mm group (controls), 18 patients in the 36 mm group and 13 patients in the 40 mm group. A total of four patients had identical bilateral prostheses in situ at phlebotomy: one each in the 28 mm and 36 mm groups and two in the 40 mm group.

There was a significant increase in the mean levels of cobalt ions in the blood in those with a 36 mm diameter femoral head compared with those with a 28 mm diameter head (p = 0.013). The levels of cobalt ions in the blood were raised in those with a 40 mm diameter head but there was no statistically significant difference between this group and the control group (p = 0.152). The levels of chromium ions in the blood were normal in all patients.

The clinical significance of this finding is unclear, but we have stopped using femoral heads with a diameter of ≤ 36 mm, and await further larger studies to clarify whether, for instance, this issue particularly affects this combination of components.

Cite this article: Bone Joint J 2014;96-B:43–7.

14.1% of men & 22.8% of women over 45 years show symptoms of osteoarthritis OA of the knee [1]. Knee OA is usually associated with lower limb malalignment [2]; 50 of varus results in 70% −90% increase in compressive loading of the medial tibio-femoral compartment [3] and OA worsening over 18 months [4]. High Tibial Osteotomy (HTO) enables preservation of bone stock and soft tissue structures and could be an attractive option to younger patients who wish to return to high level activity. However, results of HTOs are unpredictable, which could be due to patient selection or surgical techniques. The long-term aim of this work is to develop a predictive tool to aid the surgeon in the selection of optimal HTO geometry for improved and more consistent surgical outcomes. The first step in achieving our longterm goal was to determine whether stress predictions at the tibio-femoral articulation were sensitive to simulated high tibial osteotomy, using finite element (FE) method.

CT and MRI data of a cadaveric knee were used to create geometrically accurate 3D models of the femur, tibia, fibula, menisci and cartilage and tendon of the knee joint, using the Mimics V12.11 commercially-available software (Materialise, Belgium). The Simulation module was used to register the bones and the soft tissues. The resulting STL files were exported to CATIA V5R18 pre-processor to generate surface meshes and create the corresponding 3D solid and FE models of the osseous and soft tissues from the STL cloud of points.

The Young’s moduli for cortical bone, cancellous bone, cartilages, menisci and ligaments were taken from literature as 17 GPa, 500 MPa, 12 MPa, 60 Mpa and 1.72 MPa respectively [5,6,7]. The Poisson’s ratios for osseous and soft tissues were taken as 0.3 and 0.45, respectively [8]. The nodes between the bones and the corresponding cartilages were merged and surface contact was applied between the cartilages. The distal ends of the tibia and fibula were fixed and a load of 2.1 KN, corresponding to 3 x body weight, was applied perpendicularly to the proximal end of the femur. Results of finite element analyses show a reduction of 67 % in principal stresses in the knee joint following an open wedge HTO surgery simulating 100 varus correction.

FE analysis results of this study show that HTO reduces stresses in specific regions of the knee, which are associated with OA progression [4]. Our future works include corroborating our results with controlled cadaveric experiments and implementing optimization techniques to predict optimum HTO geometries for patient-specific FE models.

Background: Psychosocial factors are well-known contributors to the suffering and disability associated with common musculoskeletal problems. How to identify salient obstacles to recovery or return to work, and how to manage them effectively remains difficult. This project interpreted the evidence base and presented it as solution-focused guidance for everyday practical use by the key players (clinicians, employers, funders, case managers, etc) to help people remain active and working.

Methods and Results: Two methods were used to identify evidence and practical advice, and synthesize this into use-able statements:

existing reviews;

An extended conceptual development of a ‘flags framework’, based on the earlier approach of Yellow Flags, was used to prepare an easily understood and pragmatic approach. The framework integrates obstacles related to the person (yellow flags), the workplace (blue flags) and the context (black flags). A full-colour 32-page document suitable for distribution as both print and electronic media was developed. This contains a clear explanation of how to identify psychosocial flags, how to develop a plan to address them effectively, and how to take action to overcome the obstacles. Poster-style summaries for clinicians, the workplace, and the individual are included, and are available for download. International consultation was used to ensure system-independent applicability and language.

Conclusion: The new document provides practical guidance on identifying and managing psychosocial issues relevant to common musculoskeletal problems based on the latest evidence and conceptual approaches.

Conflict of Interest: none

Sources of Funding: Society for Back Pain Research, Faculty of Occupational Medicine, BackCare, Transport for London, Royal Mail, HCML, TSO

Introduction: Systematic reviews have found that sitting at work is not associated with LBP, although the biomechanical evidence does offer plausible causative mechanisms. Indeed, exposure to lumbar postures has been assessed using imprecise tools that have limited epidemiological investigations. The aim of this study was to use new technology to measure the seated lumbar postures of sedentary (call centre) workers, and survey their current and future symptoms in order to determine associations with LBP.

Methods: A fibre-optic goniometer (FOG) system was attached to the lumbar spine and hip of 181 sedentary call centre workers at the start of their working shift. The lumbar FOG provides a continuous measure of sagittal lumbar curvature (lumbar position and movement), whilst the hip FOG enables quantification of sitting time. Baseline and 6-month follow-up questionnaires were used to collected symptom data, and logistic regression was used to determine associations between postural and symptom (yes/no) data.

Results: Workers spent a mean proportion of 83% of work-time sitting, with 17% sitting for more than 90 minutes without a break. Current LBP (symptoms lasting more than 24hrs) was associated with a kyphotic (mean lumbar angle> 180°) sitting posture (yes/no) (OR 2.1, 1.1–4.1), although movement (mean standard deviation and angular velocity °sec-1) in sitting was not. Sitting relatively static (AV< 4.26° yes/no) (OR 3.30, 1.06–10.25), using a small amount of range (SD< 10.2° yes/no) (OR 3.79, 1.2–11.7), and adopting a kyphotic posture (yes/no) (OR 2.75, 1.02–7.3) all significantly increased the risk of future LBP.

Discussion: Sitting postures at work are associated with current LBP and are statistically significant risks for recurrence. These results highlight the potential for ergonomic interventions to reduce current symptoms and the risk of future episodes. The findings from this study are novel, and the FOG system should now be used in larger investigations of sedentary risk factors for LBP.

Background: Many sedentary workers will experience low back pain (LBP) whilst sitting, and some will believe that work caused their symptoms. They also report that their symptoms can be aggravated or relieved by work. Little is known about sedentary workers’ beliefs about the causes of back pain or symptom modifying factors (SMFs), and this study sought to determine their influence on absence.

Methods: 600 call centre workers completed validated questionnaires concerning beliefs about work-related causes of LBP in sedentary work and SMFs. Three constructs for work-related causes of LBP (physical demands; work environment; work organisation), and three groups of SMFs (physical aggravating; movement relieving; and postural relieving factors) were measured. A 6-month follow-up survey identified workers who did and did not take absence due to LBP. Logistic regression was used to predict future absence.

Results: Results indicated that, on their own, beliefs about the work environment (OR 1.2, 95% CI 1.1–1.4), and work organisation (OR 1.2, 95% CI 1.0–1.3) were significant risks for future absence (P< 0.001). Physical aggravating factors also represented a significant risk (OR 1.3, 95% CI 1.1–1.4, P< 0.001). Perceived physical demands and relieving factors were not significant (P> 0.05). The multivariable model showed that physical aggravating factors accounted for 16% of the variance (OR 1.3, 95% CI 1.1–1.4).

Conclusions: Beliefs about the work environment/organisation and physical aggravating factors are significant risks for future absence, although when considered together, physical aggravating factors dominate. These results highlight the potential for ergonomic interventions to reduce symptom-aggravating aspects of work to reduce absence.

Clinical outcomes of surgery for disc herniation and spinal stenosis are variable. Surveys show that postoperative management is inconsistent; spinal surgeons and their patients are uncertain about what best to do post-operatively. Following a focused literature review, a patient-centred, evidence-based booklet was developed, which aims to reduce uncertainty, guide post-operative management and facilitate recovery. Initial peer and patient evaluations were encouraging and the booklet Your back operation (www.tso.co.uk/bookshop) is currently factored into a trial investigating the post-operative management of spinal patients.

To date, 80 patients have been recruited into the study of which 34 have been randomised to receive the booklet. At 6 months post-surgery all of these patients are requested to complete a questionnaire on the booklet. This questionnaire contained forced-choice questions on readability, style, information level, believability, length, content and helpfulness. Further open questions concern the booklet’s messages, giving patients the opportunity to identify anything they did not like or understand, voice any concerns that were not covered, and say if they thought the booklet would change what they did after surgery. Finally, they were asked their overall rating of the booklet on a scale from 1 to 10.

Feedback is very positive. The average overall rating of the booklet was 8.6/10. Over 80% found it easy to read, interesting, and of appropriate length. Over 80% also stated they had learnt new and helpful information. All subjects stated that they would recommend the booklet to a friend, and the majority stated that they frequently referred to the booklet. The predominant messages received and understood by the patients were related to the safe benefits of early activation and return to normal activities.

The results show that spinal surgery patients appreciate evidence-based information in booklet form, and suggest that this booklet may be an important adjunct to post-operative management of spinal patients.

Background/purpose: Clinical outcomes of surgery for disc herniation and spinal stenosis are variable. Surveys show that post-operative management is inconsistent, and spinal surgeons and their patients are uncertain about what best to do during the recovery phase. The aim of this study was to develop a patient-centred, evidence-based booklet that spinal surgeons can give to their patients to reduce uncertainty, guide post-operative management and facilitate recovery.

Methods: A systematic literature search led to a best-evidence synthesis of appropriate information and advice on post-operative activation, restrictions, rehabilitation, and expectations about surgical and functional outcomes. Data were extracted into evidence statements which were graded by consensus for consistency and practicality so as to inform and prioritise the booklet’s messages. Following peer review (n = 16), a sample of patients (n = 11) gave a structured evaluation of the draft text.

Results: The review found scant evidence in favour of post-operative activity restriction, yet an early active approach to post-operative rehabilitation can improve clinical, functional and occupational outcomes. Thus, the text of the booklet presents carefully selected messages to reduce uncertainty, promote positive beliefs, encourage early reactivation, and provide practical advice to aid self-management. Peer reviewers’ comments were incorporated into the text; all the spinal surgeons (n = 7) said they would find the booklet useful. Patients found it readable, interesting and helpful; they understood and accepted the intended messages.

Conclusions: Following careful development, an evidence-based booklet to aid post-operative management in spinal surgery is now available, and is factored into a RCT of post-surgical rehabilitation.

Purpose and Background: Despite widespread clinical belief, a previous systematic review found insufficient evidence to substantiate fear avoidance beliefs (FAB) as a risk factor for long-term problems in low back pain. This updated review explores whether there is stronger evidence supporting the role of fear avoidance in early stages of low back pain as a predictor of outcome. In addition, this evidence was examined in reference to current models and knowledge about fear avoidance.

Methods and Results: A systematic literature search for all prospective inception cohorts of low back pain that included psychological factors at baseline between 2000 and 2003 was made. We searched MEDLINE, psychINFO, AMED, CINAHL, Social Science Citation Index, Science Citation Index databases. Included studies had early recruitment of up to three weeks since onset of back pain and an absence of back pain in the previous three months. These studies were coded according to criteria adapted from Pincus et al (2002) blindly by two researchers. A sample of these was coded by a third blinded reviewer. An independent statistician performed statistical conversion of reported results to effect sizes. Out of the six included studies, four included valid and reliable measures of fear avoidance. There was only weak evidence implicating fear avoidance as a predictor of disadvantageous outcome.

Conclusions: There is insufficient evidence to support or refute the basic concept of fear avoidance as a risk factor for poor outcomes in low back pain. Experimental studies indicate that those with high FAB benefit from targeted intervention. To explain this we propose a model of FAB containing two distinct groups.

Study design: A systematic review of prospective cohort studies in low back pain.

Objectives: To evaluate the evidence implicating psychological factors in the development of chronicity in low back pain.

Summary of background: The biopsychosocial model is gaining acceptance in low back pain, and has provided a basis for screening measurements, guidelines and interventions. However, to date, the unique contribution of psychological factors in the transition from an acute presentation to chronicity has not been rigorously assessed.

Methods: A systematic literature search was followed by the application of three sets of criteria to each study: methodological quality, quality of measurement of psychological factors, and quality of statistical analysis. Two reviewers blindly coded each study, followed by independent assessment by a statistician. Studies were divided into three environments: primary care, pain clinics and workplace-based studies.

Results: Twenty-five publications (18 cohorts) included psychological factors at baseline. Six of these met acceptability criteria for methodology, psychological measurement and statistical analysis. Increased risk of chronicity (persisting symptoms and/or disability) from depressive mood and, to a lesser extent, somatisation emerged as the main findings. Acceptable evidence generally was not found for other psychological factors, although weak support emerged for the role of catastrophising as a coping strategy.

Conclusions: Both depressive mood and somatisation are implicated in the transition to chronic low back pain. The development and testing of clinical interventions specifically targeting these factors is indicated. In view of the importance attributed to other psychological factors, there is a need to clarify their role in back-related disability through rigorous prospective studies.

Study design: A systematic review of the literature to inform the development of occupational health guidelines for the management of low back pain at work.

Objectives: To evaluate the evidence from occupational health settings or concerning occupational outcomes.

Summary of background: Clinical guidelines for the management of low back pain (LBP) provide only limited guidance on the occupational aspects. Thus the Faculty of Occupational Medicine requested this review in order that a multi-disciplinary working group could develop the first evidence-based UK guidelines for management of LBP at work.

Methods: A systematic literature search was followed by rating of the strength of the evidence plus a narrative review, by agreement between two experienced and independently-minded reviewers. There was no attempt at blinded double review or quality scoring. The final version followed peer-review by four international experts.

Results: More than 2000 titles were considered. 34 systematic reviews, 28 narrative reviews, 52 additional scientific studies, 22 less rigorous scientific studies and 17 previous guidelines were identified and included. The evidence statements (rated for strength) were presented under headings that reflect a logical sequence of occupational health situations (Background, Pre-placement assessment, Prevention, Assessment of the worker presenting with back pain, Management principles for the worker presenting with back pain, Management of the worker having difficulty returning to normal occupational duties at 4–12 weeks). Some important areas were given additional narrative evidence-linked discussion (High risk patients/physically demanding jobs, Return to work with back pain, Rehabilitation programmes). Thirty six evidence-linked statements were developed to inform the guidelines group. The strongest evidence suggests that: generally the physical demands at work have only a modest influence on the incidence of LBP or permanent spinal damage; a history of LBP is not a reason to deny employment; preventive strategies based on the injury model do not reduce LBP or work loss; individual and work-related psychosocial factors play an important role in persisting symptoms and work loss; the management approach should be ‘active’ (including early work return); the combination of clinical, rehabilitation and organisational interventions designed to assist work return is more effective than single elements. However, further research is needed to identify the optimal roles of all stakeholders (clinicians, employers and workers) in case management.

Conclusions: This review consolidates the emerging focus on active management of LBP at work, and indicates that approaches addressing obstacles to recovery will provide greater benefits than attempts at primary prevention. The outcome of the review has resulted in what we believe are the first truly evidence-linked occupational health guidelines for back pain in the world (www.facoccmed.ac.uk).

Traditional biomedical/ergonomic occupational interventions to reduce work loss show limited success. Attention is now focussing on tackling the psychosocial factors that influence occupational back pain.

A workforce survey of Glaxo Smith Kline (reported to the Society last year) established that clinical and occupational psychosocial factors (yellow & blue flags) act independently and may represent obstacles to recovery. Consequently, a nurse-led intervention was devised. Occupational nurses at two manufacturing sites were trained to identify both clinical and occupational psychosocial factors, and address them using a basic ‘counselling’ technique that reinforces evidence-based messages and advice, along with availability of modified work. The program should ideally be implemented within the first days of absence, with ‘case-management’ by the nurse for a further 4 weeks. Control sites simply offer ‘usual management’. Outcomes at 12-month follow-up are rates for work loss/work retention.

The target for contacting the worker (3 days) was achieved at one site, but not the other (mean 12 days), thus exerting a differential delay in delivering the intervention. The lack of early identification at the second site was due to local reporting/recording mechanisms. This study reveals a third class of obstacles to recovery – black flags – company policies/procedures that can impede occupational rehabilitation programs.

A review of scientific literature on whiplash associated disorders was conducted to inform appropriate messages for an evidenced based patient educational booklet, “The Whiplash Book.” The booklet is being developed for use as both a clinical tool and general health intervention.

A systematic literature search was conducted, using MEDLINE and psychINFO, together with hand searches, reference tracking, and the Internet. The Quebec Task Force report and the British Columbia Whiplash Initiative were taken as the starting point. The new evidence covered the period May 1994 through March 2001 (147 articles). All relevant articles were included, with a particular focus on management and treatment of whiplash associated disorders. The quantity, consistency and relevance of all retrieved articles was evaluated, and rated as *** for consistent findings in multiple reports, ** for consensus based on balance of various findings, or * for limited information (single report).

The main messages from the literature suggest: physical serious injury is rare, reassurance about good prognosis is important, over-medication is detrimental, fastest recovery occurs with early return to normal pre-accident activities, self-exercise/manual therapy and positive attitudes/beliefs are helpful to regain activities levels, collars/rest and negative attitudes/beliefs delay recovery and contribute to chronicity.