Biocompatibility of Antifogging SiO-doped Diamond-Like Carbon Laparoscope Coatings.

Laparoscopes can suffer from fogging and contamination difficulties, resulting in a reduced field of view during surgery. A series of diamond-like carbon films, doped with SiO, were produced by pulsed laser deposition for evaluation as biocompatible, antifogging coatings. DLC films doped with SiO demonstrated hydrophilic properties with water contact angles under 40°. Samples subjected to plasma cleaning had improved contact angle results, with values under 5°. Doping the DLC films with SiO led to an average 40% decrease in modulus and 60% decrease in hardness. Hardness of the doped films, 12.0 - 13.2 GPa, was greater than that of the uncoated fused silica substrate, 9.2 GPa. The biocompatibility was assessed through CellTiter-Glo assays, with the films demonstrating statistically similar levels of cell viability when compared to the control media. The absence of ATP released by blood platelets in contact with the DLC coatings suggests in vivo hemocompatibility. The SiO doped films displayed improved transparency levels in comparison to undoped films, achieving up to an average of 80% transmission over the visible spectrum and an attenuation coefficient of 1.1 × 104 cm-1 at the 450 nm wavelength. The SiO doped DLC films show promise as a method of fog prevention for laparoscopes.

Understanding the burden of injury in children from conflict: an analysis of radiological imaging from a Role 3 hospital in Afghanistan in 2011.

INTRODUCTION: There is a need for quality medical care for children injured in conflict, but a description of injuries and injury burden from blast and ballistic mechanisms is lacking. The radiology records of children imaged during the war in Afghanistan represent a valuable source of information about the patterns of paediatric conflict injuries. METHODS: The UK military radiological database was searched for all paediatric presentations to Camp Bastion during 2011. Reports and original images were reviewed to determine location and severity of injuries sustained. Additional information was obtained from imaging request forms and the Joint Theatre Trauma Register, a database of those treated at UK medical facilities in Iraq and Afghanistan. RESULTS: Radiology was available for 219 children. 71% underwent CT scanning. 46% suffered blast injury, 22% gunshot wounds (GSWs), and 32% disease and non-battle injuries (DNBIs). 3% had penetrating head injury, 11% penetrating abdominal trauma and 8% lower limb amputation, rates far exceeding those found in civilian practice. Compared with those with DNBI, those with blast or GSW were more likely to have serious (Abbreviated Injury Score, AIS, ≥3) injuries (median no. AIS ≥3 injuries were 1 for blast, 1 for GSW and 0 for DNBI, p<0.05) and children exposed to blast were more likely to have multiple body regions with serious injuries (OR for multiple AIS ≥3 injuries for blast vs DNBI=5.811 CI [1.877 to 17.993], p<0.05). CONCLUSIONS: Paediatric conflict injuries are severe, and clinicians used only to civilian practice may be unprepared for the nature and severity of injuries inflicted on children in conflict. Whole-body CT for those with conflict-related injuries, especially blast, is hugely valuable. We recommend that CT is used for paediatric assessment in blast and ballistic incidents and that national imaging guidelines amend the threshold for doing so.

Relationship between combat-related traumatic injury and ultrashort term heart rate variability in a UK military cohort: findings from the ADVANCE study.

INTRODUCTION: Combat-related traumatic injury (CRTI) has been linked to an increased cardiovascular disease (CVD) risk. The long-term impact of CRTI on heart rate variability (HRV)-a robust CVD risk marker-has not been explored. This study investigated the relationship between CRTI, the mechanism of injury and injury severity on HRV. METHODS: This was an analysis of baseline data from the ArmeD SerVices TrAuma and RehabilitatioN OutComE (ADVANCE) prospective cohort study. The sample consisted of UK servicemen with CRTI sustained during deployment (Afghanistan, 2003-2014) and an uninjured comparison group who were frequency matched to the injured group based on age, rank, deployment period and role in theatre. Root mean square of successive differences (RMSSD) was measured as a measure of ultrashort term HRV via <16 s continuous recording of the femoral arterial pulse waveform signal (Vicorder). Other measures included injury severity (New Injury Severity Scores (NISS)) and injury mechanism. RESULTS: Overall, 862 participants aged 33.9±5.4 years were included, of whom 428 (49.6%) were injured and 434 (50.3%) were uninjured. The mean time from injury/deployment to assessment was 7.91±2.05 years. The median (IQR) NISS for those injured was 12 (6-27) with blast being the predominant injury mechanism (76.8%). The median (IQR) RMSSD was significantly lower in the injured versus the uninjured (39.47 ms (27.77-59.77) vs 46.22 ms (31.14-67.84), p<0.001). Using multiple linear regression (adjusting for age, rank, ethnicity and time from injury), geometric mean ratio (GMR) was reported. CRTI was associated with a 13% lower RMSSD versus the uninjured group (GMR 0.87, 95% CI 0.80-0.94, p<0.001). A higher injury severity (NISS ≥25) (GMR 0.78, 95% CI 0.69-0.89, p<0.001) and blast injury (GMR 0.86, 95% CI 0.79-0.93, p<0.001) were also independently associated with lower RMSSD. CONCLUSION: These results suggest an inverse association between CRTI, higher severity and blast injury with HRV. Longitudinal studies and examination of potential mediating factors in this CRTI-HRV relationship are needed.

Focused Assessment with Sonography in Trauma (FAST) performance in paediatric conflict injury.

AIM: To evaluate the efficacy of Focused Assessment with Sonography in Trauma (FAST) in a paediatric population with a substantial proportion of penetrating abdominal injuries. MATERIALS AND METHODS: FAST and computed tomography (CT) abdomen findings were compared for 98 children who presented to Camp Bastion during the war in Afghanistan in 2011. FAST performance was compared to the reference standard of free fluid detected on CT. Whether children presented alone or as part of a group was also ascertained from the radiology database. RESULTS: Of the 98 patients, 20 had free fluid on CT and 15 were FAST positive. Fourteen of the 98 (14%) had penetrating wounds to the abdominal cavity. For the whole cohort FAST sensitivity was 65% (41-85%) and specificity 97% (91-100%). For those with penetrating abdominal injury sensitivity was 64% (31-89%) and specificity was 100% (40-100%). In total, 45% arrived at the same time as another casualty, and 30% arrived with other injured children. CONCLUSION: FAST performance in this population was similar to that reported in the context of paediatric blunt trauma, with high specificity for intra-abdominal free fluid. This is the first time this has been demonstrated in a cohort containing children with penetrating abdominal trauma. A substantial proportion of children presented as part of a group, necessitating simultaneous triage of multiple injured patients. FAST has a role to play in conflict medicine and mass casualty scenarios where rapid access to CT may not be feasible.

Real-Time Interface Algorithm for Ankle Kinematics and Stiffness From Electromyographic Signals.

Shortcomings in capabilities of below-knee (transtibial) prostheses, compared to their biological counterparts, still cause medical complications and functional deficit to millions of amputees around the world. Although active (powered actuation) transtibial prostheses have the potential to bridge these gaps, the current control solutions limit their efficacy. Here we describe the development of a novel interface for two degrees-of-freedom position and stiffness control for below-knee amputees. The developed algorithm for the interface relies entirely on muscle electrical signals from the lower leg. The algorithm was tested for voluntary position and stiffness control in eight able-bodied and two transtibial amputees and for voluntary stiffness control with foot position estimation while walking in eight able-bodied and one transtibial amputee. The results of the voluntary control experiment demonstrated a promising target reaching success rate, higher for amputees compared to the able-bodied individuals (82.5% and 72.5% compared to 72.5% and 68.1% for the position and position and stiffness matching tasks respectively). Further, the algorithm could provide the means to control four stiffness levels during walking in both amputee and able-bodied individuals while providing estimates of foot kinematics (gait cycle cross-correlation >75% for the sagittal and >90% for the frontal plane and gait cycle root mean square error <7.5° in sagittal and <3° in frontal plane for able-bodied and amputee individuals across three walking speeds). The results from the two experiments demonstrate the feasibility of using this novel algorithm for online control of multiple degrees of freedom and of their stiffness in lower limb prostheses.

Skin and soft tissue infections and current antimicrobial prescribing practices in Australian aged care residents.

To determine the burden of skin and soft tissue infections (SSTI), the nature of antimicrobial prescribing and factors contributing to inappropriate prescribing for SSTIs in Australian aged care facilities, SSTI and antimicrobial prescribing data were collected via a standardised national survey. The proportion of residents prescribed ⩾1 antimicrobial for presumed SSTI and the proportion whose infections met McGeer et al. surveillance definitions were determined. Antimicrobial choice was compared to national prescribing guidelines and prescription duration analysed using a negative binomial mixed-effects regression model. Of 12 319 surveyed residents, 452 (3.7%) were prescribed an antimicrobial for a SSTI and 29% of these residents had confirmed infection. Topical clotrimazole was most frequently prescribed, often for unspecified indications. Where an indication was documented, antimicrobial choice was generally aligned with recommendations. Duration of prescribing (in days) was associated with use of an agent for prophylaxis (rate ratio (RR) 1.63, 95% confidence interval (CI) 1.08-2.52), PRN orders (RR 2.10, 95% CI 1.42-3.11) and prescription of a topical agent (RR 1.47, 95% CI 1.08-2.02), while documentation of a review or stop date was associated with reduced duration of prescribing (RR 0.33, 95% CI 0.25-0.43). Antimicrobial prescribing for SSTI is frequent in aged care facilities in Australia. Methods to enhance appropriate prescribing, including clinician documentation, are required.

The critical size of a defect in the glenoid causing anterior instability of the shoulder after a Bankart repair, under physiological joint loading.

AIMS: Patients with recurrent anterior dislocation of the shoulder commonly have an anterior osseous defect of the glenoid. Once the defect reaches a critical size, stability may be restored by bone grafting. The critical size of this defect under non-physiological loading conditions has previously been identified as 20% of the length of the glenoid. As the stability of the shoulder is load-dependent, with higher joint forces leading to a loss of stability, the aim of this study was to determine the critical size of an osseous defect that leads to further anterior instability of the shoulder under physiological loading despite a Bankart repair. PATIENTS AND METHODS: Two finite element (FE) models were used to determine the risk of dislocation of the shoulder during 30 activities of daily living (ADLs) for the intact glenoid and after creating anterior osseous defects of increasing magnitudes. A Bankart repair was simulated for each size of defect, and the shoulder was tested under loading conditions that replicate in vivo forces during these ADLs. The critical size of a defect was defined as the smallest osseous defect that leads to dislocation. RESULTS: The FE models showed a high risk of dislocation during ADLs after a Bankart repair for anterior defects corresponding to 16% of the length of the glenoid. CONCLUSION: This computational study suggests that bone grafting should be undertaken for an anterior osseous defect in the glenoid of more than 16% of its length rather than a solely soft-tissue procedure, in order to optimize stability by restoring the concavity of the glenoid.

Impact of participation in a surgical site infection surveillance network: results from a large international cohort study.

BACKGROUND: Surveillance of surgical site infections (SSIs) is a core component of effective infection control practices, though its impact has not been quantified on a large scale. AIM: To determine the time-trend of SSI rates in surveillance networks. METHODS: SSI surveillance networks provided procedure-specific data on numbers of SSIs and operations, stratified by hospitals' year of participation in the surveillance, to capture length of participation as an exposure. Pooled and procedure-specific random-effects Poisson regression was performed to obtain yearly rate ratios (RRs) with 95% confidence intervals (CIs), and including surveillance network as random intercept. FINDINGS: Of 36 invited networks, 17 networks from 15 high-income countries across Asia, Australia and Europe participated in the study. Aggregated data on 17 surgical procedures (cardiovascular, digestive, gynaecological-obstetrical, neurosurgical, and orthopaedic) were collected, resulting in data concerning 5,831,737 operations and 113,166 SSIs. There was a significant decrease in overall SSI rates over surveillance time, resulting in a 35% reduction at the ninth (final) included year of surveillance (RR: 0.65; 95% CI: 0.63-0.67). There were large variations across procedure-specific trends, but strong consistent decreases were observed for colorectal surgery, herniorrhaphy, caesarean section, hip prosthesis, and knee prosthesis. CONCLUSION: In this large, international cohort study, pooled SSI rates were associated with a stable and sustainable decrease after joining an SSI surveillance network; a causal relationship is possible, although unproven. There was heterogeneity in procedure-specific trends. These findings support the pivotal role of surveillance in reducing infection rates and call for widespread implementation of hospital-based SSI surveillance in high-income countries.

Experimental platforms to study blast injury.

Injuries sustained due to attacks from explosive weapons are multiple in number, complex in nature, and not well characterised. Blast may cause damage to the human body by the direct effect of overpressure, penetration by highly energised fragments, and blunt trauma by violent displacements of the body. The ability to reproduce the injuries of such insults in a well-controlled fashion is essential in order to understand fully the unique mechanism by which they occur, and design better treatment and protection strategies to alleviate the resulting poor long-term outcomes. This paper reports a range of experimental platforms that have been developed for different blast injury models, their working mechanism, and main applications. These platforms include the shock tube, split-Hopkinson bars, the gas gun, drop towers and bespoke underbody blast simulators.

Carbapenemase-producing Enterobacteriaceae in Australian hospitals: outcome of point-prevalence screening in high-risk wards.

Carbapenemase-producing Enterobacteriaceae (CPE) infections are increasingly reported in Australian hospitals, but prevalence is unknown. In 2016, Victorian hospitals conducted CPE point-prevalence surveys in high-risk wards (intensive care, haematology, transplant). Forty-three hospitals performed 134 surveys, with 1839/2342 (79%) high-risk patients screened. Twenty-four surveys were also performed in other wards. Inability to obtain patient consent was the leading reason for non-participation. In high-risk wards, no CPE cases were detected; three cases were identified in other wards. Since there is low prevalence in high-risk wards, continuous screening is not recommended. Targeted screening may be enhanced by review of patient consent processes.

Infection prevention quality indicators in aged care: ready for a national approach.

Accreditation standards for Australian aged care homes include the requirement for programs to ensure infections are controlled. Effective infection prevention programs are supported by surveillance data providing the impetus for quality improvement and facilitating evaluation of interventions at the facility level. In 2016, infection control professionals employed in Victorian public-sector residential aged care services were surveyed to examine the nature and resourcing of local infection prevention programs and monitoring activities. Overall, 164 services participated (90% response rate). A high proportion (84%) reported executive support for infection surveillance, with mean allocation of 12h per fortnight per facility for infection prevention activities. Current surveillance activities included monitoring of infections and antimicrobial use (90%), influenza vaccination compliance for staff (96%) and residents (76%) and monitoring of infection due to significant organisms (84%). A successful statewide program including eight quality indicators has subsequently been implemented in Victoria. We suggest that a national focus could strengthen this framework, ensuring a uniform strategy with enhanced benchmarking capacity. Stakeholder engagement and refinement of appropriate indicators for monitoring quality improvement in public, not-for-profit and private sectors within aged care is required.

Central and peripheral line-associated bloodstream infections in Australian neonatal and paediatric intensive care units: findings from a comprehensive Victorian surveillance network, 2008-2016.

BACKGROUND: Healthcare-associated infections in neonatal and paediatric populations are associated with poorer outcomes and healthcare costs, and surveillance is a necessary component of prevention programmes. AIM: To evaluate burden of illness, aetiology, and time-trends for central and peripheral line-associated bloodstream infection (CLABSI and PLABSI) in Australian neonatal and paediatric intensive care units (ICUs) between July 1st, 2008 and December 31st, 2016. METHODS: Using National Healthcare Safety Network methods, surveillance in neonatal and paediatric units was performed by hospitals participating in the Victorian Healthcare Associated Infection Surveillance System. Mixed effects Poisson regression was used to model infections over time. FINDINGS: Overall, 82 paediatric CLABSI events were reported during 37,125 CVC-days (2.21 per 1000 CVC-days), 203 neonatal CLABSI events were reported during 92,169 CVC-days (2.20 per 1000 CVC-days), and 95 neonatal PLABSI events were reported during 142,240 peripheral line-days (0.67 per 1000 peripheral line-days). Over time, a significant decrease in quarterly risk for neonatal CLABSI events was observed (risk ratio (RR): 0.98; 95% confidence interval: 0.97-0.99; P = 0.023) and this reduction was significant for the 751-1000 g birth weight cohort (RR: 0.97; P = 0.015). Most frequently, coagulase-negative Staphylococcus spp. (24.2%) and Staphylococcus aureus (16.1%) were responsible for CLABSI events. A significant reduction in Gram-negative neonatal infections was observed (annual RR: 0.85; P < 0.001). CONCLUSION: CLABSI rates in neonatal and paediatric ICUs in our region are low, and neonatal infections have significantly diminished over time. Evaluation of infection prevention programmes is required to determine whether specific strategies can be implemented to further reduce infection risk.

Validation of healthcare-associated infection surveillance in smaller Australian hospitals.

A validation study was conducted in smaller (<100 acute beds) Victorian hospitals to evaluate case detection for Staphylococcus aureus bloodstream (SAB), meticillin-resistant S. aureus (MRSA) and vancomycin-resistant enterococci (VRE) infections. Overall, 142 infections were identified in 20 hospitals. For routine surveillance of SAB events, sensitivity was 74.4% and specificity was 100.0%. For MRSA infections, sensitivity was 47.5% and specificity was 90.9%. All confirmed VRE infections were reported correctly. Of unreported SAB and MRSA infections, 80% (N = 16) and 83.9% (N = 26) were community-associated infections, respectively. Future programme refinements include targeted education to ensure appropriate application of case definitions, particularly those including community onset.

Central line-associated bloodstream infections in Australian ICUs: evaluating modifiable and non-modifiable risks in Victorian healthcare facilities.

Central line-associated bloodstream infections (CLABSIs) in intensive care units (ICUs) result in poor clinical outcomes and increased costs. Although frequently regarded as preventable, infection risk may be influenced by non-modifiable factors. The objectives of this study were to evaluate organisational factors associated with CLABSI in Victorian ICUs to determine the nature and relative contribution of modifiable and non-modifiable risk factors. Data captured by the Australian and New Zealand Intensive Care Society regarding ICU-admitted patients and resources were linked to CLABSI surveillance data collated by the Victorian Healthcare Associated Infection Surveillance System between 1 January 2010 and 31 December 2013. Accepted CLABSI surveillance methods were applied and hospital/patient characteristics were classified as 'modifiable' and 'non-modifiable', enabling longitudinal Poisson regression modelling of CLABSI risk. In total, 26 ICUs were studied. Annual CLABSI rates were 1·72, 1·37, 1·00 and 0·93/1000 CVC days for 2010-2013. Of non-modifiable factors, the number of non-invasively ventilated patients standardised to total ICU bed days was found to be independently associated with infection (RR 1·07; 95% CI 1·01-1·13; P = 0·030). Modelling of modifiable risk factors demonstrated the existence of a policy for mandatory ultrasound guidance for central venous catheter (CVC) localisation (RR 0·51; 95% CI 0·37-0·70; P < 0·001) and increased number of sessional specialist full-time equivalents (RR 0·52; 95% CI 0·29-0·93; P = 0·027) to be independently associated with protection against infection. Modifiable factors associated with reduced CLABSI risk include ultrasound guidance for CVC localisation and increased availability of sessional medical specialists.

Epidemiology of infections and antimicrobial use in Australian haemodialysis outpatients: findings from a Victorian surveillance network, 2008-2015.

BACKGROUND: Patients with chronic renal failure who require haemodialysis are at high risk for infections. AIM: To determine the burden of bloodstream and local access-related infections and the prescribing patterns for intravenous antibiotics in Australian haemodialysis outpatients. METHODS: A surveillance network was established following stakeholder consultation, with voluntary participation by haemodialysis centres and data collation by the Victorian Healthcare Associated Infection Surveillance System Coordinating Centre. Definitions for infection and intravenous antimicrobial starts were based upon methods employed by the Centers for Disease Control and Prevention. Longitudinal mixed-effects Poisson regression was used to model time-trends for the period 2008-2015. FINDINGS: Forty-eight of 78 Victorian dialysis centres participated in the network, with 3449 events reported over 78,826 patient-months. Rates of bloodstream infection, local infection and intravenous antimicrobial starts were much higher for patients with tunnelled central lines (2.60, 1.41, and 3.37 per 100 patient-months, respectively), compared to those with arteriovenous fistulae (0.27, 0.23, and 0.73 per 100 patient-months, respectively) and arteriovenous grafts (0.76, 1.08, 1.50 per 100 patient-months, respectively). Staphylococcus aureus was the most frequent pathogen, with meticillin-resistant isolates (MRSA) responsible for 14.0%. Access-related infections diminished significantly across all vascular-access modalities over time. Vancomycin contributed nearly half of all antimicrobial starts consistently throughout the study period. CONCLUSION: Risk for bloodstream and local access-related infections is highest in Australian haemodialysis patients with tunnelled central lines. S. aureus is the most frequent cause of infection, with a low incidence of MRSA. Future programmes should evaluate infection prevention practices and appropriateness of antibiotic prescribing in this population.

Lentiviral gene rescue of a Bernard-Soulier mouse model to study platelet glycoprotein Ibß function.

UNLABELLED: Essentials A signaling role of glycoprotein (GP)Ibß is postulated but not formally demonstrated in platelets. Lentiviral-mediated rescue in knock-out mice can be used to evaluate GPIbß function in vivo. Transduction of the native subunit corrected the main defects associated with GPIb-IX deficiency Deletion of intracellular 159-170 segment increased thrombosis, 150-160 removal increased bleeding. SUMMARY: Background The platelet glycoprotein (GP)Ib-V-IX complex is required for normal hemostasis and megakaryopoiesis. A role in GPIb-dependent responses has been ascribed to the less well characterized GPIbß subunit using a specific antibody and GPIb-IX transfected cells. Objectives Our aim was to evaluate, in vivo, the role of the GPIbß in hemostasis and thrombosis. Methods GPIbß(null) Sca-1(+) progenitors transduced with viral particles harboring hGPIbß were transplanted into lethally irradiated GPIbß(-/-) recipient mice. Results hGPIbß transplanted into the bone marrow of GPIbß(null) mice rescued GPIb-IX expression in 97% of circulating platelets. These platelets efficiently bound von Willebrand factor (VWF) and extended filopodia on a VWF matrix, demonstrating the restoration of GPIb-dependent adhesive and signaling properties. These mice exhibited less severe macrothrombocytopenia and had normal tail bleeding times as compared with GPIbß(null) mice. This strategy was employed to manipulate and evaluate the role of the GPIbß intracellular domain. Removal of the membrane proximal segment (Δ(150-160) ) decreased GPIb-IX expression by 43%, confirming its involvement in receptor assembly and biosynthesis, and resulted in increased bleeding times and decreased thrombosis in a mechanical injury model in the aorta. On the other hand, deletion of the C-flanking 159-170 segment allowed normal GPIb-IX expression, VWF-dependent responses and bleeding times, but resulted in enhanced arterial thrombosis. Conclusion This pointed to a repressor role of GPIbß in thrombus formation in vivo that was not predicted in studies of heterologous cells. These results highlight the utility of this lentiviral strategy for the structure-function evaluation of GPIb-IX in platelets.

Epidemiology of Clostridium difficile infections in Australia: enhanced surveillance to evaluate time trends and severity of illness in Victoria, 2010-2014.

BACKGROUND: With epidemic strains of Clostridium difficile posing a substantial healthcare burden internationally, there is a need for longitudinal evaluation of Clostridium difficile infection (CDI) events in Australia. AIM: To evaluate time trends and severity of illness for CDI events in Australian healthcare facilities. METHODS: All CDI events in patients admitted to Victorian public hospitals between 1(st) October 2010 and 31(st) December 2014 were reported to the Victorian Healthcare Associated Infection Surveillance System. CDI was defined as the isolation of a toxin-producing C. difficile organism in a diarrhoeal specimen, and classified as community-associated (CA-CDI) or healthcare-associated (HA-CDI). Severe disease was defined as admission to an intensive care unit, requirement for surgery and/or death due to infection. Time trends were examined using a mixed-effects Poisson regression model, and the Walter and Edward test of seasonality was applied to evaluate potential cyclical patterns. FINDINGS: In total, 6736 CDI events were reported across 89 healthcare facilities. Of these, 4826 (71.6%) were HA-CDI, corresponding to a rate of 2.49/10,000 occupied bed days (OBDs). The incidence of HA-CDI was highest in the fifth quarter of surveillance (3.6/10,000 OBDs), followed by a reduction. Severe disease was reported in 1.66% of events, with the proportion being significantly higher for CA-CDI compared with HA-CDI (2.21 vs 1.45%, P = 0.03). The highest and lowest incidence of HA-CDI occurred in March and October, respectively. CONCLUSIONS: A low incidence of HA-CDI was reported in Victoria compared with US/European surveillance reports. Seasonality was evident, together with diminishing HA-CDI rates in 2012-2014. Severe infections were more common in CA-CDI, supporting future enhanced surveillance in community settings.

Posterior mini-incision total hip arthroplasty controls the extent of post-operative formation of heterotopic ossification.

Heterotopic ossification (HO) is the formation of bone at extra-skeletal sites. Reported rates of HO after hip arthroplasty range from 8 to 90 %; however, it is only severe cases that cause problems clinically, such as joint stiffness. The effects of surgical-related controllable intra-operative risk factors for the formation of HO were investigated. Data examined included gender, age of patient, fat depth, length of operation, incision length, prosthetic fixation method, the use of pulsed lavage and canal brush, and component size and material. All cases were performed by the same surgeon using the posterior approach. A total of 510 cases of hip arthroplasty were included, with an overall rate of HO of 10.2 %. Longer-lasting operations resulted in higher grades of HO (p = 0.047). Incisions >10 cm resulted in more widespread HO formation (p = 0.021). No further correlations were seen between HO formation and fat depth, blood loss, instrumentation, fixation methods or prosthesis material. The mini-incision approach is comparable to the standard approach in the aetiology of HO formation, and whilst the rate of HO may not be controllable, a posterior mini-incision approach can limit its extent.

Biomechanical determinants of elite rowing technique and performance.

In rowing, the parameters of injury, performance, and technique are all interrelated and in dynamic equilibrium. Whilst rowing requires extreme physical strength and endurance, a high level of skill and technique is essential to enable an effective transfer of power through the rowing sequence. This study aimed to determine discrete aspects of rowing technique, which strongly influence foot force production and asymmetries at the foot-stretchers, as these are biomechanical parameters often associated with performance and injury risk. Twenty elite female rowers performed an incremental rowing test on an instrumented rowing ergometer, which measured force at the handle and foot-stretchers, while three-dimensional kinematic recordings of the ankle, knee, hip, and lumbar-pelvic joints were made. Multiple regression analyses identified hip kinematics as a key predictor of foot force output (R(2) = 0.48), whereas knee and lumbar-pelvic kinematics were the main determinants in optimizing the horizontal foot force component (R(2) = .41). Bilateral asymmetries of the foot-stretchers were also seen to significantly influence lumbar-pelvic kinematics (R(2) = 0.43) and pelvic twisting (R(2) = 0.32) during the rowing stroke. These results provide biomechanical evidence toward aspects of technique that can be modified to optimize force output and performance, which can be of direct benefit to coaches and athletes.