Search

Oncimmune's EarlyCDT®-Lung is a simple ELISA blood test that measures seven lung cancer specific autoantibodies and is used in the assessment of malignancy risk in patients with indeterminate pulmonary nodules (IPNs). The objective of this study was to examine the cost-effectiveness of EarlyCDT-Lung in the diagnosis of lung cancer amongst patients with IPNs in addition to CT surveillance, compared to CT surveillance alone which is the current recommendation by the British Thoracic Society guidelines. A model consisting of a combination of a decision tree and Markov model was developed using the outcome measure of the quality adjusted life year (QALY). A life-time time horizon was adopted. The model was parameterized using a range of secondary sources. At £70 per test, EarlyCDT-Lung and CT surveillance was found to be cost-effective compared to CT surveillance alone with an incremental cost-effectiveness ratio (ICER) of less than £2,500 depending on the test accuracy parameters used. It was also found that EarlyCDT-Lung can be priced up to £1,177 and still be cost-effective based on cost-effectiveness acceptance threshold of £20,000 / QALY. Further research to resolve parameter uncertainty, was not found to be of value. The results here demonstrate that at £70 per test the EarlyCDT-Lung will have a positive impact on patient outcomes and coupled with CT surveillance is a cost-effective approach to the management of patients with IPNs. The conclusions drawn from this analysis are robust to realistic variation in the parameters used in the model.

Background Detachment of the central tendon of the supraspinatus from its insertion is considered to be crucial to functional deficit. The aim of the present study was to assess the function of the supraspinatus in terms of abduction moments by introducing different tear configurations to assess the functional effect of the central tendon insertion. Methods Ten fresh frozen shoulders from five cadavers were prepared for testing. A testing protocol was established to measure the abduction moment of the supraspinatus under physiological loading tailored to the anthropometrics of each specimen. Four conditions were tested: intact supraspinatus; complete detachment of portion of the supraspinatus tendon anterior to the main central tendon; detachment of the main central tendon; and detachment of the region of the supraspinatus posterior to the main central tendon. Results There was a significant and large reduction in abduction moment when the central tendon was sectioned ( p Conclusions The central tendon is vital in the role of functional arm abduction through force transmission through the intact rotator cuff. Reinsertion of the central tendon in the correct anatomical location is desirable to optimize functional outcome of surgery.

OBJECTIVES:: Due to the absence of clinical blast data, automotive injury data using the abbreviated injury score (AIS) has been extrapolated to define current North Atlantic Treaty Organisation (NATO) injury thresholds for anti-vehicle mine tests. We hypothesized that AIS, being a marker of fatality rather than disability, would be a worse predictor of poor clinical outcome compared with the lower limb-specific foot and ankle severity score (FASS). METHODS:: Using a prospectively collected trauma database, we identified UK Service Personnel sustaining lower leg injuries from under-vehicle explosions from January 2006 to December 2008. A full review of all medical documentation was performed to determine patient demographics and the severity of lower leg injury, as assessed by AIS and FASS. Clinical endpoints were defined as (1) need for amputation or (2) poor clinical outcome (defined as amputation or ongoing clinical problems). Statistical models were developed to explore the relationship between the scoring systems and clinical endpoints. RESULTS:: Sixty-three UK casualties (89 limbs) were identified with a lower limb injury after under-vehicle explosion. The mean age of the casualty was 26.0 years. At 33.6 months follow-up, 29.1% (26 of 89) required an amputation and 74.6% (67 of 89) having a poor clinical outcome. Only 9 (14%) casualties were deemed medically fit to return to full military duty. Receiver operating characteristic analysis revealed that both AIS = 2 and FASS = 4 could predict the risk of amputation, with FASS = 4 demonstrating greater specificity (43% vs. 20%) and greater positive predictive value (72% vs. 34%). In predicting poor clinical outcome, FASS was significantly superior to AIS. Probit analysis revealed that a relationship could not be developed between AIS and the probability of a poor clinical outcome. CONCLUSIONS:: Our study clearly demonstrates that AIS is not a predictor of long-term clinical outcome and that FASS would be a better quantitative measure of lower limb injury severity. Language: en

Background Type II superior labral (SLAP) tears commonly occur in athletes in the abducted and externally rotated position in the late cocking phase of throwing. This study investigates arthroscopic repairs of SLAP lesions using a knotless polymeric (KINSA) anchor. Methods Superficial tissues were dissected from 10 cadaveric shoulders. The glenohumeral capsule was preserved. Type II SLAP tears were created through arthroscopic portals and repaired with two anchors anterior and posterior to the biceps tendon. Glenohumeral joints were then fixed in 60° gleno-humeral abduction in the scapular plane with 1 Nm torque in external rotation to recreate the late cocking phase of the throwing cycle. Specimens were mounted onto an Instron machine and the biceps tendon was loaded until failure. Results The mean ultimate peak load was 239 N (SD 101 N). The primary mode of failure was in the tendon substance and 19 out of 20 anchors remained intact in bone. Conclusion To our knowledge this is the first study to investigate arthroscopic SLAP repairs in an intact joint in this susceptible position. We conclude that the KINSA anchor can withstand high tensile loads and may be used to treat SLAP tears in high-demand overhead throwing athletes.

Purpose The aim of the study was to define the normalized compressive stiffness (modulus) of the glenoid labrum around its circumference and to characterize the difference in modulus between different areas. Methods Sixteen fresh-frozen cadaveric shoulders were harvested and dissected down to the glenoid labrum. Any specimens with significant degenerative changes were discarded, leaving 8 labra for testing. The labrum was divided into 8 segments, to allow comparison around its circumference. A uniform testing specimen was produced from each area by use of a microtome. Each specimen measured 3 × 1 mm in cross section and was 6 mm in length. Indentation testing was conducted in a controlled environment of 100% humidity at 37°C ± 1°C. Results We obtained 52 test samples from 8 labra. The mean modulus of the glenoid labrum was 69.7 megapascal (standard deviation, 36.2 megapascal). The anterosuperior portion of the labrum had a higher modulus than the posteroinferior portion ( P = .0075). Conclusions This study has shown that the human glenoid labrum's compressive behavior varies around its circumference. The greater modulus of the anterosuperior portion of the labrum supports the theory that this area is anatomically different from the rest of the labrum and resists compressive loads. Clinical Relevance These results may explain why the common type of SLAP lesions seen show failure at the interface between the labrum and the glenoid rather than within the substance of the labrum itself.

There is wealth of data from experimental and numerical methods of analysing and modelling soft connective tissues of joints. In recent years, the advances in computational and technological capabilities allowed for several aspects of the function and mechanical behaviour of soft connective tissues of joints to be explored. However, the nature of soft tissue poses a great challenge in characterizing its material behaviour in a repeatable and physiologically or clinically relevant manner. This review article attempts to present, critique, and suggest experimental and numerical methods that are associated with the function and mechanical response of soft connective tissues of joints.

Summary There is a wealth of data published on the biomechanical properties of intra-articular tissues. However, much of this information is not intuitively applicable to clinical practice due to both methodological disparity between studies and the relevance of the methodology used to test the biomaterial. This inevitably results in comparison difficulties with other experimental data produced for the same tissue, or indeed different tissues. Therefore, this review highlights the salient issues that need to be considered when trying to interpret biomechanical testing scenarios and how they influence clinical practice. As such, different testing protocols and their clinical relevance are scrutinised. The importance of recreating the physiological loading conditions and the interpretation of the functional anatomy are highlighted.

Highly active anti-retroviral therapy has transformed HIV into a chronic disease with a long-term asymptomatic phase. As a result, emphasis is shifting to other effects of the virus, aside from immunosuppression and mortality. We have reviewed the current evidence for an association between HIV infection and poor fracture healing. The increased prevalence of osteoporosis and fragility fractures in HIV patients is well recognised. The suggestion that this may be purely as a result of highly active anti-retroviral therapy has been largely rejected. Apart from directly impeding cellular function in bone remodelling, HIV infection is known to cause derangement in the levels of those cytokines involved in fracture healing (particularly tumour necrosis factor-α) and appears to impair the blood supply of bone. Many other factors complicate this issue, including a reduced body mass index, suboptimal nutrition, the effects of anti-retroviral drugs and the avoidance of operative intervention because of high rates of wound infection. However, there are sound molecular and biochemical hypotheses for a direct relationship between HIV infection and impaired fracture healing, and the rewards for further knowledge in this area are extensive in terms of optimised fracture management, reduced patient morbidity and educated resource allocation. Further investigation in this area is overdue.

Summary Assessment of the glenohumeral joint relies upon a detailed, time-dependent history of the presenting complaint and a thorough examination of its subtle signs. As such, the complex is most appropriately approached as a unit, rather than as a discrete number of examinable components. However, understanding the interactions between these components means that a high level of skill is needed to adequately assess the joint, and learning these skills is compounded by the large number of eponymous tests described for examining separate elements. The stabilising mechanisms of the shoulder may crudely be classified as passive (non-contractile) or active (contractile) in function; this artificial distinction neglects the role of contractile tissue in maintaining stability whilst not contracting, but serves to facilitate understanding, and indeed categorise modes and methods of physical examination. Indeed, modes of failure are specific to these groupings. Determining the degree of instability caused by the passive stabilising mechanisms is commonly fraught with both intra- and inter-rater discrepancy, and as such, requires a great deal of experience to implement and interpret. However, an evidence-based approach to a clinical examination sequence can improve its predictive value. A critical review of the literature on examination of passive stabilising mechanisms is presented, followed by a distillation of current concepts resulting in the presentation of an evidence-based approach to examination that is practical, and can be implemented successfully by all involved in the rehabilitation process.

The glenoid labrum is a significant passive stabilizer of the shoulder joint. However, its microstructural form remains largely unappreciated, particularly in the context of its variety of functions. The focus of labral microscopy has often been histology and, as such, there is very little appreciation of collagen composition and arrangement of the labrum, and hence the micromechanics of the structure. On transmission electron microscopy, significant differences in diameter, area and perimeter were noted in the two gross histological groups of collagen fibril visualized; this suggests a heterogeneous collagenous composition with potentially distinct mechanical function. Scanning electron microscopy demonstrated three distinct zones of interest: a superficial mesh, a dense circumferential braided core potentially able to accommodate hoop stresses, and a loosely packed peri-core zone. Confocal microscopy revealed an articular surface fine fibrillar mesh potentially able to reduce surface friction, bundles of circumferential encapsulated fibres in the bulk of the tissue, and bone anchoring fibres at the osseous interface. Varying microstructure throughout the depth of the labrum suggests a role in accommodating different types of loading. An understanding of the labral microstructure can lead to development of hypotheses based upon an appreciation of this component of material property. This may aid an educated approach to surgical timing and repair.

Measurement of upper limb motion is problematic, not least because of the large range of path dependent description of motion of the joints, and the multiple non-cyclical unstandardised motion tasks measured. Furthermore, appreciation of shoulder motion specifically is obscured by overlying soft tissue. In order to satisfy the complexity of a clinically useful model of the movement of the joint, input data must be acquired from a set of pre-determined movements using a non-invasive technique with a high level of accuracy. Descriptive and predictive modeling of the glenohumeral joint requires input of high-fidelity data into a 6 degree of freedom representation, without which, the application of the tool is of limited clinical significance to the advancement of both operative and non-operative management of shoulder pathology. Electromagnetic, linkage and radiographic techniques have previously been used, however, an optimal solution is yet to be described.

Capsular plication or thermal shrinkage can be used to enhance surgical joint stabilization. We compared mechanical or morphologic properties of the medial collateral ligament of the rabbit knee treated by either bipolar radiofrequency electrothermal shrinkage or surgical plication. After 12 weeks, the medial collateral ligaments were procured from treated and contralateral knees to undergo viscoelastic (creep) testing, quantitative transmission electron microscopy, and immunohistochemistry. Creep strain in thermal (1.85% +/- 0.32%) and plicated (1.92% +/- 0.36%) ligaments was almost twice that of the control group (1.04% +/- 0.15%), although there was no difference between treatment modalities. The morphologic parameters of all 3 groups were significantly different (P.001). The thermal ligaments demonstrated predominantly small fibrils, whereas the plicated group displayed an intermediate distribution of heterogeneous fibrils, suggesting a different pattern of remodeling. Viscoelastic properties are similar after thermal shrinkage or plication, though inferior to those of intact ligaments.

Background: Measuring isokinetic strength of the shoulder complex is potentially an important clinical tool in both diagnosis and management of injury and pathology. However, a clinically relevant position is yet to be established. Objectives: To establish an appropriate and repeatable protocol to evaluate the functional strength of both internal and external rotators of the glenohumeral joint to enable assessment of clinical injury management and training related developments in upper limb strength. Methods: A population cross-sectional study of shoulder internal and external rotational strengths of 17 normal, healthy volunteers (11 males, 6 females) aged 21 to.45 years were measured both isokinetically and isometrically. Two test positions: seated and supine, were compared by way of reliability and repeatability analyses. Humeral rotation was performed at 45° of abduction in the scapular plane seated, and at 90° of abduction in the supine position. Results: Throughout concentric testing, when the population was considered as a whole the left shoulder data appeared more repeatable than the right shoulder. This however, was not evident when the study population was divided into single sex groupings. Equally, whilst the repeatability trend of sitting vs. supine position was skewed towards the former, more evident in the left shoulder, this was less apparent when sexes were analysed separately. All comparative measures were statistically insignificant. Conclusion: The findings of this study suggest that measurements of isokinetic shoulder rotation strength are highly prone to both joint specific and non-specific errors.

This study compared the strength and fatigue characteristics of the trunk in international rowers and non-rowing controls. 39 international rowers (mean age 27.4 ± 4.9, 20 females, 19 males) and 35 control subjects who did not row (mean age 23.2 ± 3.2, 20 males, 15 females) were recruited and parameters of trunk flexion-extension strength including isometric fatigue were recorded tested on a Cybex Norm Isokinetic Testing System. The rowers were significantly stronger ( P< 0.001) in all measured parameters of back strength than the control group (isometric extension strength 249.3 N/m ± 52.1 (SD) in rowers compared with 178.6 N/m ± 85 (SD) in controls). Greater strength in the rowing group was most significant in the later stages of range. Both populations demonstrated marked fatigue of the trunk muscles, although this was more prominent in the rowers ( p< 0.05 in flexion). In general, values of extensor strength were markedly greater than flexion strength, although this was less so in rowers. Consequently the trunk extensor-flexor ratios were lower in the rowing population. In conclusion, elite rowers are significantly stronger than control subjects. It is of interest that these strength gains are not proportional throughout range and this may be related to the rowing action, and may be of importance with respect to future development of LBP.

BACKGROUND: Improvements in protection and medical treatments have resulted in increasing numbers of modern-warfare casualties surviving with complex lower-extremity injuries. To our knowledge, there has been no prior analysis of foot and ankle blast injuries as a result of improvised explosive devices (IEDs). The aims of this study were to report the pattern of injury and determine which factors are associated with a poor clinical outcome. METHODS: U.K. service personnel who had sustained lower leg injuries following an under-vehicle explosion from January 2006 to December 2008 were identified with the use of a prospective trauma registry. Patient demographics, injury severity, the nature of the lower leg injury, and the type of clinical management were recorded. Clinical end points were determined by (1) the need for amputation and (2) ongoing clinical symptoms. RESULTS: Sixty-three U.K. service personnel (eighty-nine injured limbs) with lower leg injuries from an explosion were identified. Fifty-one percent of the casualties sustained multisegmental injuries to the foot and ankle. Twenty-six legs (29%) required amputation, with six of them amputated because of chronic pain eighteen months following injury. Regression analysis revealed that hindfoot injuries, open fractures, and vascular injuries were independent predictors of amputation. At the time of final follow-up, sixty-six (74%) of the injured limbs had persisting symptoms related to the injury, and only nine (14%) of the service members were fit to return to their preinjury duties. CONCLUSIONS: This study demonstrates that foot and ankle injuries from IEDs are associated with a high amputation rate and frequently with a poor clinical outcome. Although not life-threatening, they remain a source of long-term morbidity in an active population. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. Language: en

Current military conflicts are characterized by the use of the improvised explosive device. Improvements in personal protection, medical care, and evacuation logistics have resulted in increasing numbers of casualties surviving with complex musculoskeletal injuries, often leading to life-long disability. Thus, there exists an urgent requirement to investigate the mechanism of extremity injury caused by these devices in order to develop mitigation strategies. In addition, the wounds of war are no longer restricted to the battlefield; similar injuries can be witnessed in civilian centers following a terrorist attack. Key to understanding such mechanisms of injury is the ability to deconstruct the complexities of an explosive event into a controlled, laboratory-based environment. In this article, a traumatic injury simulator, designed to recreate in the laboratory the impulse that is transferred to the lower extremity from an anti-vehicle explosion, is presented and characterized experimentally and numerically. Tests with instrumented cadaveric limbs were then conducted to assess the simulator’s ability to interact with the human in two mounting conditions, simulating typical seated and standing vehicle passengers. This experimental device will now allow us to (a) gain comprehensive understanding of the load-transfer mechanisms through the lower limb, (b) characterize the dissipating capacity of mitigation technologies, and (c) assess the bio-fidelity of surrogates.

We discuss the problem of 2D+t intra- and inter-sequential registration of retinal angiograms. A joint spatio-temporal registration algorithm is presented based on a RANSAC (RANdom SAmple Consensus) approach incorporating a quadratic model to describe “pairwise” image homography. This is incorporated into a local-to-global hierarchical joint registration framework. After registration, vessel centrelines are segmented to subpixel accuracy by applying multi-scale steerable complex wavelet filters. Frame-by-frame microvascular centrelines in Regions-of-Interest (ROIs) are evaluated against segmented centrelines of the temporal average of the registered sequences. The microvascular centrelines in registered sequences can be compared intra-sequentially and inter-sequentially, allowing non-invasive clinical monitoring of micro-circulation. This has the potential to detect the presence of microemboli and pathological structural alterations.

Since World War I, explosions have accounted for over 70% of all injuries in conflict. With the development of improved personnel protection of the torso, improved medical care and faster aeromedical evacuation, casualties are surviving with more severe injuries to the extremities. Understanding the processes involved in the transfer of blast-induced shock waves through biological tissues is essential for supporting efforts aimed at mitigating and treating blast injury. Given the inherent heterogeneities in the human body, we argue that studying these processes demands a highly integrated approach requiring expertise in shock physics, biomechanics and fundamental biological processes. This multidisciplinary systems approach enables one to develop the experimental framework for investigating the material properties of human tissues that are subjected to high compression waves in blast conditions and the fundamental cellular processes altered by this type of stimuli. Ultimately, we hope to use the information gained from these studies in translational research aimed at developing improved protection for those at risk and improved clinical outcomes for those who have been injured from a blast wave.

BACKGROUND:: Anti-vehicle mines and improvised explosive devices remain the most prevalent threat to coalition troops operating in Iraq and Afghanistan. Detonation of these devices causes rapid deflection of the vehicle floor resulting in severe injuries to calcaneus. Anecdotally referred to as a "deck-slap" injury, there have been no studies evaluating the pattern of injury or the effect of these potentially devastating injuries since World War II. Therefore, the aim of this study is to determine the pattern of injury, medical management, and functional outcome of UK Service Personnel sustaining calcaneal injuries from under-vehicle explosions. METHOD:: From January 2006 to December 2008, using a prospectively collected trauma registry (Joint Theater Trauma Registry), the records of all UK Service Personnel sustaining a fractured calcaneus from a vehicle explosion were identified for in-depth review. For each patient, demographic data, New Injury Severity Score, and associated injuries were recorded. In addition, the pattern of calcaneal fracture, the method of stabilization, local complications, and the need for amputation were noted. Functional recovery was related to the ability of the casualty to return to military duties. RESULTS:: Forty calcaneal fractures (30 patients) were identified in this study. Mean follow-up was 33.2 months. The median New Injury Severity Score was 17, with the lower extremity the most severely injured body region in 90% of cases. Nine (30%) had an associated spinal injury. The overall amputation rate was 45% (18/40); 11 limbs (28%) were amputated primarily, with a further 3 amputated on return to the United Kingdom. Four (10%) casualties required a delayed amputation for chronic pain (mean, 19.5 months). Of the 29 calcaneal fractures salvaged at the field hospital, wound infection developed in 11 (38%). At final follow-up, only 2 (6%) were able to return to full military duty with 23 (76%) only fit for sedentary work or unfit for any military duty. CONCLUSION:: Calcaneal injuries following under-vehicle explosions are commonly associated with significant multiple injuries including severe lower limb injury. The frequency of associated spinal injuries mandates radiologic evaluation of the spine in all such patients. The severity of the hindfoot injury is reflected by the high infection rate and amputation rate. Only a small proportion of casualties were able to return to preinjury military duties. Language: en

We report the outcome of 161 of 257 surgically fixed acetabular fractures. The operations were undertaken between 1989 and 1998 and the patients were followed for a minimum of ten years. Anthropometric data, fracture pattern, time to surgery, associated injuries, surgical approach, complications and outcome were recorded. Modified Merle D’Aubigné score and Matta radiological scoring systems were used as outcome measures. We observed simple fractures in 108 patients (42%) and associated fractures in 149 (58%). The result was excellent in 75 patients (47%), good in 41 (25%), fair in 12 (7%) and poor in 33 (20%). Poor prognostic factors included increasing age, delay to surgery, quality of reduction and some fracture patterns. Complications were common in the medium- to long-term and functional outcome was variable. The gold-standard treatment for displaced acetabular fractures remains open reduction and internal fixation performed in dedicated units by specialist surgeons as soon as possible.

The conflicts in Iraq and Afghanistan have been epitomized by the insurgents' use of the improvised explosive device against vehicle-borne security forces. These weapons, capable of causing multiple severely injured casualties in a single incident, pose the most prevalent single threat to Coalition troops operating in the region. Improvements in personal protection and medical care have resulted in increasing numbers of casualties surviving with complex lower limb injuries, often leading to long-term disability. Thus, there exists an urgent requirement to investigate and mitigate against the mechanism of extremity injury caused by these devices. This will necessitate an ontological approach, linking molecular, cellular and tissue interaction to physiological dysfunction. This can only be achieved via a collaborative approach between clinicians, natural scientists and engineers, combining physical and numerical modelling tools with clinical data from the battlefield. In this article, we compile existing knowledge on the effects of explosions on skeletal injury, review and critique relevant experimental and computational research related to lower limb injury and damage and propose research foci required to drive the development of future mitigation technologies.

Improved protective measures and medical care has increased the survivability from battlefield injuries. In an attempt to reduce the debilitating consequences of blast injury, understanding and mitigating the effects of explosion on the extremities is key. In this study, forensic biomechanical analyses have been applied to determine mechanisms of injury after the traumatic event. The aims of this study were (i) to determine which effects of the explosion are responsible for combat casualty extremity bone injury in two distinct environments, namely open, free-field (open group), and in vehicle or in cover (enclosed group), and (ii) to determine whether patterns of combat casualty bone injury differed between environments. Medical records of casualties admitted to a military hospital in Afghanistan were reviewed over a six-month period. Explosive injuries have been sub-divided traditionally into primary, secondary and tertiary effects. All radiographs were independently reviewed by a military radiologist, a team of military orthopaedic surgeons and a team of academic biomechanists, in order to determine ‘zones of injury’ (ZoIs), and their related mechanisms. Sixty-two combat casualties with 115 ZoIs were identified. Thirty-four casualties in the open group sustained 56 ZoIs; 28 casualties in the enclosed group sustained 59 ZoIs. There was no statistical difference in mean ZoIs per casualty between groups ( p = 0.54). There was a higher proportion of lower limb injuries in the enclosed group compared with the open group ( p < 0.05). Of the casualties in the open group, 1 ZoI was owing to the primary effects of blast, 10 owing to a combination of primary and secondary blast effects, 23 owing to secondary blast effects and 24 owing to tertiary blast effects. In contrast, tertiary blast effects predominated in the enclosed group, accounting for 96 per cent of ZoIs. These data clearly demonstrate two distinct injury groups based upon the casualties' environment. The enclosed environment appears to attenuate the primary and secondary effects of the explosion. However, tertiary blast effects were the predominant mechanism of injury, with severe axial loading to the lower extremity being a characteristic of the fractures seen. The development of future mitigation strategies must focus on reducing all explosion-related injury mechanisms. Integral to this process is an urgent requirement to better understand the behaviour of bone in this unique environment.

Introduction Anti-vehicle (AV) mines have been laid indiscriminately in conflict areas for the past 100 years. With an indeterminate life-span they continue to pose a significant threat to the civilian population, as well as restrict the movement of people, aid and goods to vulnerable populations. The aim of this study was to analyse unique casualty data from 2212 mine incidents to determine if simple vehicle modifications can reduce fatality and injury rates from mine explosions. Method We analysed casualty data from the Rhodesian War (1972–1980), to assess the effects of basic vehicle modifications (V-shaped hull, increased ground clearance, widened axles, heavy vehicles and blast deflectors) on injury rates. A multinomial regression statistical model was developed for vehicle modifications and number of alterations to explore these effects. Results Incident data was available on 2212 vehicle mine incidents involving 16,456 people. The overall fatality rate was 3.3% (544/16,456) and the overall injury rate was 22.7% (3741/16,456). Explosions against mine-protected vehicles resulted in a fatality rate of 1.2% (150/12,919); occupants in unprotected vehicles sustained a fatality rate of 11.4% (395/3537). The injury rate in mine protected vehicles was 22.2% (2868/12,919) compared to 24.7% in unprotected vehicles (873/3537). Utilising a multinomial logistical-regression model, we show that each design feature significantly reduced fatality rate (from 45% in unprotected vehicles to 0.8% in protected vehicles); each of these designs had a cumulative effect in fatality reduction. In isolation, blast deflectors, whilst reducing fatality rates, increased injury rates. Conclusions Our data clearly demonstrates that simple vehicle modifications can have a significant effect on reducing fatality and injury rates from AV mine explosions. Given that the modifications described were produced using commercially available vehicles with basic engineering requirements, we believe that similar processes could be employed in post-conflict environments in a cost-effective manner.

Aims The efficacy of endovenous treatments for venous reflux has been demonstrated in numerous randomised clinical trials, although significant heterogeneity may exist between studies. The aim of this study was to assess the heterogeneity in reporting between randomised clinical trials investigating endovenous treatments for patients with varicose veins. Methods A literature search of the Pubmed, Cochrane and Google Scholar databases was performed using appropriate search terms. Randomised clinical trials published between January 1968 and June 2009 evaluating endovenous interventions for varicose veins were included and relevant abstracts and full text articles were reviewed. Published study reports were evaluated against recommended reporting standards published by the American Venous Forum in 2007. Results Twenty-eight randomised trials fulfilled the inclusion criteria. Median patient age (reported in 20/28 studies) ranged from 33 to 54 years. The CEAP classification was presented in 17/28 studies and the proportion of patients with C2 disease ranged from 6.3% to 83.5%. A total of 31 different outcome measures were utilised. This included 13 different questionnaires, varicose vein recurrence at 38 time points and 30 categories of complications. Duplex ultrasonography was used in 21/28 trials to assess recurrence. Quality of life was only evaluated in 11 studies and the follow-up period ranged from 3 weeks to 10 years. Conclusions Meaningful comparison across randomised studies of endovenous treatments is made difficult by considerable variations in study populations and outcome measures between trials. This highlights the need for the use of prospectively agreed population selection, and reporting standards for outcome measures in randomised clinical assessments of new treatments.

There is a paucity of data in the literature on the restraining effects of the glenohumeral (GH) ligaments; cadaveric testing is one of the best methods for determining the function of these types of tissues. The aim of this work was to commission a custom-made six degrees of freedom (dof) joint loading apparatus and to establish a protocol for laxity testing of cadaveric shoulder specimens. Nine cadaveric shoulder specimens were used in this study and each specimen had all muscle resected leaving the scapula, humerus (transected at mid-shaft) and GH capsule. Specimens were mounted on the testing apparatus with the joint in the neutral position and at 30 degrees, 60 degrees and 90 degrees GH abduction in the coronal, scapula and 30 degrees forward flexion planes. For each orientation, 0-1 N m in 0.1 N m increments was applied in internal/external rotation and the angular displacement recorded. The toe-region of the moment-displacement curves ended at approximately +/-0.5 N m. The highest rotational range of motion for the joint was 140 degrees for +/-1.0 N m at 30 degrees GH abduction in the scapula plane. The range of motion shifted towards external rotation with increasing levels of abduction. The results provide the optimum loading regime to pre-condition shoulder specimens and minimise viscoelastic effects in the ligaments prior to laxity testing (0.5 N m at 30 degrees GH abduction in any of the three planes). Knowledge of the mechanical properties of the GH capsuloligamentous complex has implications for modelling of the shoulder as well surgical planning and intervention.

Acetabular labral tears predominantly affect young patients and are a source of hip pain in the athlete. Four causes of the initiation of labral tears have been proposed; trauma, hypolaxity of the anterior capsule, dysplasia and bony impingement. A further cause could be reduced biomechanical properties in the area most susceptible to tears. However, no work has defined these properties.32 compressive and 32 tensile test samples were harvested from fresh-frozen cadaveric acetabula. The labrum was divided into eight areas to allow comparison around its circumference. Semiconfined compressive testing and tensile testing were performed at a displacement rate of 10 mm/min in a controlled environment of 100% humidity at 37 (SD 1) degrees C.Cadaveric study.The mean compressive stiffness was 31.75 (SD 16.7) MPa, and the mean tensile elastic modulus was 24.7 (SD 10.8) MPa. The anterosuperior region had a significantly lower compressive elastic modulus than either of the posterior quadrants (p0.05) and a significantly lower tensile modulus to the anterioinferior area (p0.05).The biomechanical properties in the anterosuperior region may be a contributing factor to the initiation of labral tears.

Human fresh-frozen cadaveric glenoid labrae from 16 donors were harvested and ten of these had no gross degeneration. These ten were divided into eight equal circumferential sections. Each section was cut to produce test-samples from the core layer with a cross-section of 1 x 1 mm. Tensile testing was performed within a controlled environment unit at 37 +/- 1 degrees C and 100% relative humidity. Each test-sample was precycled to a quasi-static state to alleviate the effects of deep-freezing, prior to final testing. The tangent modulus was calculated for each test-sample before and after a 5-min period of stress relaxation and at yield. The mean elastic modulus and yield stress of the glenoid labrum were 22.8 +/- 11.4 and 2.5 +/- 2.1 MPa, respectively. The anterosuperior portion had a lower elastic modulus and lower yield stress than the inferior portion (both P < 0.02). The pre-stress relaxation tangent modulus was significantly lower than the post-stress relaxation tangent modulus for all portions of the labrum. The glenoid labrum has similar tensile material properties to articular cartilage. Its elastic modulus varies around its circumference. This suggests that the labrum may encounter different forces at different positions.

Background: The optimal method for arthroscopic rotator cuff repair is not yet known. The hypothesis of the present study was that a double-row repair would demonstrate superior static and cyclic mechanical behavior when compared with a single-row repair. The specific aims were to measure gap formation at the bone-tendon interface under static creep loading and the ultimate strength and mode of failure of both methods of repair under cyclic loading. Methods: A standardized tear of the supraspinatus tendon was created in sixteen fresh cadaveric shoulders. Arthroscopic rotator cuff repairs were performed with use of either a double-row technique (eight specimens) or a single-row technique (eight specimens) with nonabsorbable sutures that were double-loaded on a titanium suture anchor. The repairs were loaded statically for one hour, and the gap formation was measured. Cyclic loading to failure was then performed. Results: Gap formation during static loading was significantly greater in the single-row group than in the double-row group (mean and standard deviation, 5.0 ± 1.2 mm compared with 3.8 ± 1.4 mm; p < 0.05). Under cyclic loading, the double-row repairs failed at a mean of 320 ± 96.9 N whereas the single-row repairs failed at a mean of 224 ± 147.9 N (p = 0.058). Three single-row repairs and three double-row repairs failed as a result of suture cut-through. Four single-row repairs and one double-row repair failed as a result of anchor or suture failure. The remaining five repairs did not fail, and a midsubstance tear of the tendon occurred. Conclusions: Although more technically demanding, the double-row technique demonstrates superior resistance to gap formation under static loading as compared with the single-row technique. Clinical Relevance: A double-row reconstruction of the supraspinatus tendon insertion may provide a more reliable construct than a single-row repair and could be used as an alternative to open reconstruction for the treatment of isolated tears.

Joint modelling plays an important role in qualitative and quantitative descriptions of both normal and abnormal joints, as well as predicting outcomes of alterations to joints in orthopaedic practice and research. Contemporary efforts in modelling have focussed upon the major articulations of the lower limb. Well-constrained arthrokinematics can form the basis of manageable kinetic and dynamic mathematical predictions. In order to contain computation of shoulder complex modelling, glenohumeral joint representations in both limited and complete shoulder girdle models have undergone a generic simplification. As such, glenohumeral joint models are often based upon kinematic descriptions of inadequate degrees of freedom (DOF) for clinical purposes and applications. Qualitative descriptions of glenohumeral motion range from the parody of a hinge joint to the complex realism of a spatial joint. In developing a model, a clear idea of intention is required in order to achieve a required application. Clinical applicability of a model requires both descriptive and predictive output potentials, and as such, a high level of validation is required. Without sufficient appreciation of the clinical intention of the arthrokinematic foundation to a model, error is all too easily introduced. Mathematical description of joint motion serves to quantify all relevant clinical parameters. Commonly, both the Euler angle and helical (screw) axis methods have been applied to the glenohumeral joint, although concordance between these methods and classical anatomical appreciation of joint motion is limited, resulting in miscommunication between clinician and engineer. Compounding these inconsistencies in motion quantification is gimbal lock and sequence dependency.

The aims of this paper are to devise robust methods for the description of the variability in shapes of long bones using 3D statistical shape models (SSMs), and to test these on a dataset of humeri that demonstrate significant variability in shape. 30 primate humeri were CT scanned and manually segmented. SSMs were constructed from a training set of landmarks. The landmarks of the 3D shapes are extracted automatically using marching cubes and point correspondences are automatically obtained via a volumetric non-rigid registration technique using multiresolution B-Spline deformations. The surface registration resulted in no discernible differences between bone shapes, demonstrating the high accuracy of the registration method. An analysis of variations is applied on the shapes based on the model we built. The first mode of variation accounted for 42% of the variation in bone shape. This single component discriminated directly between great apes (including humans) and monkeys.

The objectives of this study were to quantify the relationship between passive tension of rotator cuff repairs and arm position and to examine the effect of this tension on repair gap formation. Five patients undergoing open surgical rotator cuff repair of the supraspinatus tendon were recruited. Tendon tension was recorded as the supraspinatus was advanced into a bone trough and secured. The relationship between arm position and repair tension was then measured. Standardized rotator cuff tears were created in 3 cadaveric shoulders and repaired by use of the intraoperative technique. The difference in tension measured between 0 degrees and 30 degrees abduction was statically applied for 24 hours and the gap formation measured. Repair tension increased with advancement of the supraspinatus tendon into the bone trough. Abduction reduced the repair load. The mean reduction in load by 30 degrees abduction was 34 N. Twenty-four hours of 34-N loading caused gap formation of 9 mm in cadaveric rotator cuff repairs. Passive tension in surgically repaired rotator cuffs may contribute to repair failure and can be modified by arm positioning.