Prospective observational study investigating the predictive validity of the STarT Back tool and the clinical effectiveness of stratified care in an emergency department setting.

PURPOSE: To determine the predictive validity of the STarT Back tool (SBT) undertaken at baseline and 6 weeks to classify Emergency Department (ED) patients with LBP into groups at low, medium or high risk of persistent disability at 3 months. A secondary aim was to evaluate the clinical effectiveness of pragmatic risk-matched treatment in an ED cohort at 3 months. METHODS: A prospective observational multi-centre study took place in the physiotherapy services linked to the ED in four teaching hospitals in Dublin, Ireland. Patients were stratified into low, medium and high-risk groups at their baseline assessment. Participants received stratified care, where the content of their treatment was matched to their risk profile. Outcomes completed at baseline and 3 months included pain and disability. Linear regression analyses assessed if baseline or 6-week SBT score were predictive of disability at 3 months. Changes in the primary outcome of disability were dichotomised into those who achieved/ did not achieve a 30% improvement in their RMDQ at 6 weeks and 3 months. RESULTS: The study enrolled 118 patients with a primary complaint of LBP ± leg pain with 67 (56.7%) completing their 6-week and 3-month follow-up. Baseline RMDQ and being in medium or high risk SBT group at 6 weeks were predictive of persistent disability at 3 months. A total of 54 (80.6%) participants reported a > 30% improvement at 3 months. CONCLUSION: Disability at baseline and SBT administered at 6 weeks more accurately predicted disability at 3 months than SBT at baseline in an ED population.

Anatomically accurate 3D modelling and printing in a case of obstetric brachial plexus injury.

Obstetric brachial plexus injury is reported in 0.42 per 1000 births in UK and Ireland and are associated with a reduction in quality of life for the patient and their carers. In this report we describe the first use of a patient specific, anatomically accurate 3D model as a communication tool in the treatment of a complex case of posterior shoulder subluxation secondary to glenohumeral deformity resulting from obstetric brachial plexus injury. The use of 3D models for surgical planning is associated with decreased operating time and reduction of intra-operative blood loss, whilst their use in patient education increases patient understanding. In this case all surgeons surveyed agreed that it was useful and will use 3D modelling to improve consent processes and to conceptualise novel techniques for complex cases in future. This highly reproducible, low cost technique may be adapted to a variety of upper limb reconstructive surgeries, and as the resolution of image acquisition and additive manufacturing capabilities increase so too do the potential applications of this precise 3D printed surgical adjunct.

Open reduction for developmental dysplasia of the hip: failures of screening or failures of treatment?

INTRODUCTION: The aim of this study was to define the clinical indications and demographic characteristics of patients under-going open reduction for developmental dysplasia of the hip (DDH), and determine the proportion due to preventable failures of contemporary clinical screening and early management. METHODS: Case notes were reviewed of consecutive primary open reductions performed for non-teratologic hip dislocation at the Great Ormond Street Hospital for Children over a five-year period. Forty-eight patients (64 hips) were suitable for inclusion. A telephone survey confirmed selective hip ultrasonography screening protocols were employed in all maternity hospitals in our referral base. RESULTS: There were no cases of open reduction for unilateral DDH following Pavlik treatment commenced by six weeks of age, highlighting the importance of early detection and treatment. Eleven cases (23%) may have been avoided by appropriate implementation of existing selective ultrasonography screening protocols. Thirty-four cases (71%) presented after four months of age, suggesting open reduction is associated with late diagnosis rather than failure of primary management. None of these patients had neonatal hip ultrasonography and only 12% (4 patients) had a risk factor that should have triggered a scan. CONCLUSIONS: Compared with published results, the contemporary screening practices in our referral base are failing to eliminate late presenting DDH and the need for open surgical reduction. Changes in strategy and implementation are required to significantly improve screening efficacy.

Reciprocal inhibition versus unloading response during stretch reflex in humans.

Rotation of an upper limb joint produces excitatory stretch reflex peaks M1 and M2 in the stretched muscles and simultaneous decrease in electromyographic (EMG) activity in the shortened muscles. The objective of this study was to examine whether the decreased activity in the antagonists (rINHIB) is purely from unloading of the spindles or receives active inhibition involving inhibitory interneurons. If rINHIB is due only to unloading, then the termination of rINHIB should vary with the duration of perturbation used to elicit stretch reflex, namely shorter stretches should result in shorter values of decreased periods of EMG. To examine this question, rectangular pulses, ranging in duration from 25 to 150 ms, were used to stretch wrist flexors or extensors with a torque motor. These rectangular pulses resulted in joint rotations which peaked at times (T(peak)) ranging from approximately 75-160 ms. As shown by previous authors, when the duration of rotation was shortened, the magnitude of M1 did not change, while the magnitude of M2 decreased. However, termination time of rINHIB in the shortened muscles did not change with change in T(peak), implying thereby that unloading of spindles of the antagonist muscles is not the only mechanism for the reduction in activity and that inhibitory reflex pathways most likely contribute. Possible sources of inhibition are discussed for the short- and long-latency inhibition.

Slipped upper tibial epiphysis in infantile tibia vara: three cases.

We describe three cases of infantile tibia vara resulting from an atraumatic slip of the proximal tibial epiphysis upon the metaphysis. There appears to be an association between this condition and severe obesity. Radiologically, the condition is characterised by a dome-shaped metaphysis, an open growth plate and disruption of the continuity between the lateral borders of the epiphysis and metaphysis, with inferomedial translation of the proximal tibial epiphysis. All patients were treated by realignment of the proximal tibia by distraction osteogenesis with an external circulator fixator, and it is suggested that this is the optimal method for correction of this complex deformity. There are differences in the radiological features and management between conventional infantile Blount's disease and this 'slipped upper tibial epiphysis' variant.

Exploratory behavior during stance persists with visual feedback.

Recent evidence showing center of pressure (COP) displacements increase following an external stabilization of the center of mass (COM) supports the theory that postural sway may be exploratory and serve as a means of acquiring sensory information. The aim of the current study was to further test this theory and rule out potential confounding effects of sensory illusions or motor drift on prior observations. Participants stood as still as possible in an apparatus which allowed movements of the COM to be stabilized ("locked") without subject awareness, and they were provided real-time visual feedback of their COM or COP throughout the trial. If there was an influence of sensory illusions or motor drift, we hypothesized that the change in COP displacement with locking would be reduced when participants were provided visual confirmation of COM stabilization (COM feedback), or when they were aware of the position of the COP throughout the trial (COP feedback). Confirming our previous results, increases in COP displacement were observed when movements of the COM were stabilized. In addition, our results showed that increases in COP displacement could not be explained by the presence of sensory illusions or motor drift, since increases in COP were observed despite being provided convincing evidence that the COM had been stabilized, and when participants were aware of their COP position throughout the trial. These results provide further support for an exploratory role of postural sway. The theoretical basis of current clinical practices designed to deal with balance control deficits due to age or disease is typically based on the opinion that increases in sway are a consequence of a failing balance control system. Our results suggest that this may not be the case, and if sway is in fact exploratory, a serious re-evaluation of current clinical practices may be warranted.

Balance problems with Parkinson's disease: are they anxiety-dependent?

Non-motor symptoms, such as fear of falling and anxiety, are frequently reported in Parkinson's disease (PD). Recent evidence of anxiety and fear directly influencing balance control in healthy young and older adults, raises the question whether fear of falling and anxiety also directly contribute to the balance deficits observed in PD. The goal of the current study was to examine whether PD patients and controls responded similarly or differently to experimentally induced increases in anxiety. For this purpose, 14 PD patients (tested during a subjective optimal ON state) and 16 healthy age-matched control subjects stood in three conditions of different levels of postural threat: normal threat (quiet standing at ground level); medium threat (standing at the edge of a surface elevated to 80 cm); and high threat (same, but to 160 cm). Outcome measures included mean position, mean power of frequency (MPF) and root mean square (RMS) of centre of pressure (COP) displacements in the anterior-posterior (AP) and medial-lateral (ML) directions. Physiological and psychosocial measures of fear and anxiety were also recorded. Increased threat changed postural control similarly in PD patients and controls; MPF of AP and ML COP increased and the mean COP position was shifted backward in both groups. These results indicate that during the ON state, static balance in PD patients and controls is equally susceptible to the influence of anxiety. Significant correlations observed between COP changes and measures of fear and anxiety provide evidence to support the proposed neural links between structures controlling emotion and postural control. Future studies should further address this issue by including more severely affected patients, by testing the influence of dopaminergic medication, by including more anxious patients, and by using dynamic measures of balance.

Shifting the balance: evidence of an exploratory role for postural sway.

Humans and other species are unable to stand perfectly still; their bodies continuously sway during stance even during concentrated efforts to avoid such movement. Traditionally, this phenomenon has been viewed as an inability of the central nervous system (CNS) to maintain perfect equilibrium because of its reliance on feedback from sensory signals to control corrective ground-reaction forces. Using a novel method to minimize movements of the body during stance without subject awareness, we have made the unique discovery that ground-reaction forces are generated independent of body sway, as evidenced by observations of increased centre of pressure variability when postural sway is minimized experimentally. Contrary to traditional views, our results suggest that postural sway may be used by the CNS as an exploratory mechanism to ensure that continuous dynamic inputs are provided by multiple sensory systems. This novel paradigm has the potential to significantly shift long-standing views on balance, and questions the theoretical basis behind conventional treatment strategies for balance deficits associated with age and disease.

Recovery of human motoneurons during rotation.

During prolonged contractions, few studies have reported rotation among low threshold motoneurons. The question arises whether a motoneuron stops firing due to an increase in firing threshold or whether it is due to regional switching of activity among muscle fascicles. We postulated that if the rest period resulted from an increase in firing threshold, a progressive recovery in the excitability of the motoneuron would be observed during the rest period. The excitability of soleus or tibialis anterior motoneurons was tested during the rest periods. The results showed that a previously tonic motoneuron that had dropped off during rotation, rarely responded to Ia or TMS inputs in the initial parts of the rest period; however, its response probability increased significantly in the second half. Based on these data, we suggest that the observed rotation is due to changes in firing thresholds of motoneurons during prolonged firing.

The biology of aseptic osteolysis.

Total hip arthroplasty is one of the most commonly performed and successful elective orthopaedic procedures. However, numerous failure mechanisms limit the long-term success including aseptic osteolysis, aseptic loosening, infection, and implant instability. Aseptic osteolysis and subsequent implant failure occur because of a chronic inflammatory response to implant-derived wear particles. To reduce particulate debris and their consequences, implants have had numerous design modifications including high-molecular-weight polyethylene sockets and noncemented implants that rely on bone ingrowth for fixation. Surgical techniques have improved cementation with the use of medullary plugs, cement guns, lavage of the canal, pressurization, centralization of the stem, and reduction in cement porosity. Despite these advances, aseptic osteolysis continues to limit implant longevity. Numerous proinflammatory cytokines, such as interleukin-1, interleukin-6, tumor necrosis factor-alpha, and prostaglandin E2, have proosteoclastogenic effects in response to implant-derived wear particles. However, none of these cytokines represents a final common pathway for the process of particle-induced osteoclast differentiation and maturation. Recent work has identified the fundamental role of the RANKL-RANK-NF-kappaB pathway not only in osteoclastogenesis but also in the development and function the immune system. Thus, the immune system and skeletal homeostasis may be linked in the process of osteoclastogenesis and osteolysis.

Linezolid penetration into osteo-articular tissues.

Penetration of linezolid into osteo-articular tissue and fluid was studied in 10 patients undergoing primary total knee replacement. Linezolid 600 mg 12 hourly was given orally over the 48 h before operation and intravenously 1 h before induction of anaesthesia. Mean concentrations of linezolid at 90 min after the final dose, in serum, synovial fluid, synovium, muscle and cancellous bone, assayed by HPLC, were at least twice the MIC(90) for staphylococci and streptococci. The concentrations obtained indicate good penetration of this antibiotic and support its use in the management of multidrug-resistant Gram-positive bone, joint and deep-seated soft-tissue infections.