RESUMEN

Osseointegration implant has attracted significant attention as an alternative treatment for transfemoral amputees. It has been shown to improve patients' sitting and walking comfort and control of the artificial limb, compared to the conventional socket device. However, the patients treated with osseointegration implants require a long rehabilitation period to establish sufficient femur-implant connection, allowing the full body weight on the prosthesis stem. Hence, a robust assessment method on the osseointegration process is essential to shorten the rehabilitation period and identify the degree of osseointegration prior to the connection of an artificial limb. This paper investigates the capability of a vibration-related index (E-index) on detecting the degree of simulated osseointegration process with three lengths of the residual femur (152, 190 and 228 mm). The adhesive epoxy with a setting time of 5 min was applied at the femur-implant interface to represent the stiffness change during the osseointegration process. The cross-spectrum and colormap of the normalised magnitude demonstrated significant changes during the cure time, showing that application of these plots could improve the accuracy of the currently available diagnostic techniques. Furthermore, the E-index exhibited a clear trend with a noticeable average increase of 53% against the cure time for all three residual length conditions. These findings highlight that the E-index can be employed as a quantitative justification to assess the degree of osseointegration process without selecting and tracing the resonant frequency based on the geometry of the residual femur.

Asunto(s)

RESUMEN

Osseointegrated prostheses are widely used following transfemoral amputation. However, this technique requires sufficient implant stability before and during the rehabilitation period to mitigate the risk of implant breakage and loosening. Hence, reliable assessment methods for the osseointegration process are essential to ensure initial and long-term implant stability. This paper researches the feasibility of a vibration analysis technique for the osseointegration (OI) process by investigating the change in the dynamic response of the residual femur with a novel implant design during a simulated OI process. The paper also proposes a concept of an energy index (the E-index), which is formulated based on the normalized magnitude. To illustrate the potential of the E-index, this paper reports on changes in the vibrational behaviors of a 133 mm long amputated artificial femur model and implant system, with epoxy adhesives applied at the interface to simulate the OI process. The results show a significant variation in the magnitude of the colormap against curing time. The study also shows that the E-index was sensitive to the interface stiffness change, especially during the early curing process. These findings highlight the feasibility of using the vibration analysis technique and the E-index to quantitatively monitor the osseointegration process for future improvement on the efficiency of human health monitoring and patient rehabilitation.

Asunto(s)

RESUMEN

Reliable and quantitative assessments of bone quality and fracture healing prompt well-optimised patient healthcare management and earlier surgical intervention prior to complications of nonunion and malunion. This study presents a clinical investigation on modal frequencies associations with musculoskeletal components of human legs by using a prototype device based on a vibration analysis method. The findings indicated that the first out-of-plane and coupled modes in the frequency range from 60 to 110 Hz are associated with the femur length, suggesting these modes are suitable quantitative measures for bone evaluation. Furthermore, higher-order modes are shown to be associated with the muscle and fat mass of the leg. In addition, mathematical models are formulated via a stepwise regression approach to determine the modal frequencies using the measured leg components as variables. The optimal models of the first modes consist of only femur length as the independent variable and explain approximately 43% of the variation of the modal frequencies. The subsequent findings provide insights for further development on utilising vibration-based methods for practical bone and fracture healing monitoring.

Asunto(s)

Asunto(s)

RESUMEN

AIMS: Acetabular fractures in older adults lead to a high risk of mortality and morbidity. However, only limited data have been published documenting functional outcomes in such patients. The aims of this study were to describe outcomes in patients aged 60 years and older with operatively managed acetabular fractures, and to establish predictors of conversion to total hip arthroplasty (THA). METHODS: We conducted a retrospective, registry-based study of 80 patients aged 60 years and older with acetabular fractures treated surgically at The Alfred and Royal Melbourne Hospital. We reviewed charts and radiological investigations and performed patient interviews/examinations and functional outcome scoring. Data were provided by the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). Survival analysis was used to describe conversion to THA in the group of patients who initially underwent open reduction and internal fixation (ORIF). Multivariate regression analyses were performed to identify factors associated with conversion to THA. RESULTS: Seven patients (8.8%) had died at a median follow-up of 18 months (interquartile range (IQR) 12 to 25), of whom four were in the acute THA group. Eight patients (10%) underwent acute THA. Of the patients who underwent ORIF, 17/72 (23.6%) required conversion to THA at a median of 10.5 months (IQR 4.0 to 32.0) . After controlling for other factors, transport-related cases had an 88% lower rate of conversion to THA (hazard ratio (HR) 0.12, 95% confidence interval (CI) 0.02 to 0.91). Mean standardized Physical Component Summary Score (PCS-12) of the 12-Item Short Form Health Survey (SF-12) was comparable with the general population (age-/sex-matched) by 12 to 24 months. Over half of patients working prior to injury (14/26) returned to work by six months and two-thirds of patients (19/27) by 12 months. CONCLUSION: Patients over 60 years of age managed operatively for displaced acetabular fractures had a relatively high mortality rate and a high conversion rate to THA in the ORIF group but, overall, patients who survived had mean PCS-12 scores that improved over two years and were comparable with controls. Cite this article: Bone Joint J 2020;102-B(12):1735-1742.

Asunto(s)

RESUMEN

Introduction: The application of an external fixator for unstable pelvic fractures is an important component of many resuscitation protocols. Moreover, certain pelvic fractures may be treated with an external fixator without requiring further internal fixation. We report our initial clinical results with an alternate pelvic external fixator site, the lateral posterior external fixator (LPEF), and describe the surgical technique. Methods and Materials: From 2010 to 2013, we identified 27 consecutive patients (mean age 44.6 years, range 18-80 years) treated by the same surgeon (MKR) with an LPEF in a level 1 trauma center. Retrospective data collection included mechanism of injury, surgical interventions, and complications. Results: The LPEF was used in 16 patients as acute pelvic stabilization and converted at a median of 2 days (interquartile range 1-3.5) to internal fixation, whereas in 10 patients, it was used as definitive treatment and removed at a median of 48 days (interquartile range 37-64). One patient died on day 14, secondary to his severe closed head injury. The only surgical complications were two wound infections (20%, 2/10 in the group of definitive LPEFs), which resolved without sequelae after the removal of the LPEF (at 36 and 50 days) and antibiotics, one case of loss of fixation leading to the removal of the LPEF at 71 days, and one patient who had hypergranulating external fixator sites and eventually healed without any cutaneous sequelae. All fractures consolidated in a good position. Discussion: The described techniques of pelvic external fixation include the anterosuperior (iliac wing), supra-acetabular (anteroinferior), and subcristal (anterior superior iliac spine) insertion sites. The reported infection rates in definitive pelvic fracture treatment range from 20 to 40%. Due to the localization of the insertion sites, the lateral femoral cutaneous nerve is potentially at risk with the last two techniques. On the other hand, the LPEF insertion site is quite safe, as it is anatomically far from any nerves and the inguinal region, and allows easy access for laparotomy. The results in this series suggest that the lateral posterior pelvic external fixator technique is an alternative to previous techniques with a low risk of complications.

RESUMEN

The lack of a quantitative method to adequately assess fractured bone healing that has undergone fixation limits prognostic capabilities on patients' optimal return to work. This paper addresses the use of vibrational analysis to monitor the state of healing of a plate-screw fixated femur and supplement the current clinical radiographic assessment. This experimental study involves an osteotomised composite femur specimen enclosed by modelling clay to simulate the damping effect of overlying soft tissues. Epoxy adhesives are applied to the fractured region and to simulate the healing process. With the instrumentation described, the cross-spectrum and coherence are obtained and analysed in the frequency domain over a period of time. The results suggest that it is crucial to analyse the cross-spectrum and proposed healing index to quantitatively assess the stages of healing. The results also show that the mass loading effect due to modelling clay did not influence the proposed healing assessment technique. The findings indicate a potential non-intrusive technique to evaluate the healing of fractured femur by utilising the vibrational responses.

Asunto(s)

RESUMEN

Quantitative and reliable monitoring of osseointegration will help further evaluate the integrity of the orthopaedic construct to promote novel prosthesis design and allow early mobilisation. Quantitative assessment of the degree or the lack of osseointegration is important for the clinical management with the introduction of prosthetic implants to amputees. Acousto-ultrasonic wave propagation has been used in structural health monitoring as well as human health monitoring but so far has not extended to osseointegrated implants or prostheses. This paper presents an ultrasonic guided wave approach to assess the osseointegration of a novel implant. This study explores the potential of integrating structural health monitoring concepts into a new osseointegrated implant. The aim is to demonstrate the extension of acousto-ultrasonic techniques, which have been widely reported for the structural health monitoring of engineering structures, to assess the state of osseointegration of a bone and implant. To illustrate this potential, this paper will report on the experimental findings which investigated the unification of an aluminium implant and bone-like geometry surrogate. The core of the test specimen is filled with silicone and wrapped with plasticine to simulate the highly damped cancellous bone and soft tissue, respectively. To simulate the osseointegration process, a 2-h adhesive epoxy is used to bond the surrogate implant and a bone-like structure. A series of piezoelectric elements are bonded onto the surrogate implant to serve as actuators and sensors. The actuating piezoelectric element on an extramedullary strut is excited with a 1 MHz pulse signal. The reception of the ultrasonic wave by the sensing elements located on the adjacent and furthest struts is used to assess the integration of this implant to the parent bone structure. The study shows an Osseointegration Index can be formulated by using engineering and acousto-ultrasonic methods to measure the unification of a bone and implant. This also highlights a potential quantitative evaluation technique regardless of bone-implant geometry and soft tissue damping.

RESUMEN

OBJECTIVES: A multidisciplinary approach that emphasised improved triage, early pelvic binder application, early administration of blood and blood products, adherence to algorithmic pathways, screening with focused sonography (FAST), early computed tomography scanning with contrast angiography, angio-embolisation and early operative intervention by specialist pelvic surgeons was implemented in the last decade to improve outcomes after pelvic trauma. The manuscript evaluated the effect of this multi-faceted change over a 12-year period. METHODS: A retrospective cohort study was conducted comparing patients presenting with serious pelvic injury in 2002 to those presenting in 2013. The primary exposure and comparator variables were the year of presentation and the primary outcome variable was mortality at hospital discharge. Potential confounders were evaluated using multivariable logistic regression analysis. RESULTS: There were 1213 patients with a serious pelvic injury (Abbreviated Injury Scale ≥3), increasing from 51 in 2002 to 156 in 2013. Demographics, injury severity and presenting clinical characteristics were similar between the two time periods. There was a statistically significant difference in mortality from 20% in 2002 to 7.7% in 2013 (P = 0.02). The association between the primary exposure variable of being injured in 2013 and mortality remained statistically significant (adjusted odds ratio 0.10; 95% confidence interval: 0.02-0.60) when adjusted for potential clinically important confounders. CONCLUSIONS: Multi-faceted interventions directed at the spectrum of trauma resuscitation from pre-hospital care to definitive surgical management were associated with significant reduction in mortality of patients with severe pelvic injury from 2002 to 2013. This demonstrates the effectiveness of an integrated, inclusive trauma system in achieving improved outcomes.

Asunto(s)

RESUMEN

This article proposes a counter-argument to standard Advanced Trauma Life Support (ATLS) training--which advocates bladder catheterisation to be performed as an adjunct to the primary survey and resuscitation for early decompression of the bladder and urine output monitoring. We argue the case for delaying bladder catheterisation until after definitive truncal Computed Tomography (CT) imaging. To reduce pelvic volume and associated bleeding, our trauma team delay catheter insertion until after the initial CT scan. The benefits of a full bladder also include improved views on initial Focussed Assessment with Sonography in Trauma (FAST) scan and improved interpretation of injuries on CT. Our urinary catheter related infection rates anecdotally decreased when insertion was delayed and consequently performed in a more controlled, non-resuscitation setting following CT. Adult blunt multitrauma patients with pelvic ring fractures are at risk of significant haemorrhage. Venous, arterial and medullary injuries with associated bleeding may be potentiated by an increased pelvic volume with ring disruption, as well as a reduced pressure effect from retroperitoneal and intra-pelvic organs on bleeding sites. Various techniques are used to reduce intra-pelvic bleeding. For shocked patients who have sustained major pelvic injuries with no other signs of urinary tract trauma and minimal urine in the bladder on initial FAST scan, we advocate careful, aseptic Foley catheter insertion followed by bladder insufflation with 500-600 mL of Normal Saline (NS) and subsequent catheter clamping to tamponade pelvic bleeding.

Asunto(s)

RESUMEN

BACKGROUND: There is limited evidence describing the long-term outcomes of severe pelvic ring fractures. The aim of this study was to describe the longer term independent living and return to work outcomes following severe pelvic ring fracture. METHODS: Adult survivors to discharge from two major trauma centres with AO/Tile type B and C fractures were followed up at 6, 12 and 24-months post-injury to capture functional (Glasgow Outcome Scale-Extended [GOS-E]) and return to work data. Multivariable, mixed effects models were used to identify predictors of outcome. RESULTS: A total of 111 of 114 (97%) cases were followed up. The mean (SD) age of participants was 41.9 (18.9) years, 77% were male, 81% were transport-related and 90% were multi-trauma patients. Further, 11% were managed conservatively, 10% with external fixation and 79% with open reduction and internal fixation. At 24 months, 77% were living independently (GOS-E > 4) and 59% had returned to work. Higher Injury Severity Scores (ISS) were associated with lower risk-adjusted odds of return to work (P = 0.04) and independent living (P = 0.06). Post-operative infection was associated with living independently (P = 0.02). CONCLUSION: Despite the severity of the injuries sustained, 77% of severe pelvic ring fracture patients were living independently and 59% had returned to work, 2-years post-injury. Fracture type and management were not key predictors of outcome. Large-scale multi-centre studies are needed to fully understand the burden of severe pelvic ring fractures and to guide clinical management.

Asunto(s)

RESUMEN

Sacral fractures from high-impact trauma often cause instability in the pelvic ring structure. Treatment is by internal fixation which clamps the fractured edges together to promote healing. Healing could take up to 12 weeks whereby patients are bedridden to avoid hindrances to the fracture from movement or weight bearing activities. Immobility can lead to muscle degradation and longer periods of rehabilitation. The ability to determine the time at which the fracture is stable enough to allow partial weight-bearing is important to reduce hospitalisation time. This review looks into different techniques used for monitoring the fracture healing of bones which could lead to possible methods for in situ and non-invasive assessment of healing fracture in a fixated pelvis. Traditional techniques being used include radiology and CT scans but were found to be unreliable at times and very subjective in addition to being non in situ. Strain gauges have proven to be very effective for accurate assessment of fracture healing as well as stability for long bones with external fixators but may not be suitable for an internally fixated pelvis. Ultrasound provides in situ monitoring of stiffness recovery but only assesses local fracture sites close to the skin surface and has only been tested on long bones. Vibration analysis can detect non-uniform healing due to its assessment of the overall structure but may suffer from low signal-to-noise ratio due to damping. Impedance techniques have been used to assess properties of non-long bones but recent studies have only been conducted on non-biological materials and more research needs to be done before it can be applicable for monitoring healing in the fixated pelvis.

Asunto(s)

RESUMEN

INTRODUCTION: Traumatic disruption of the pelvic ring is uncommon but is associated with a high risk of mortality. These injuries are predominantly due to high energy blunt trauma such as a fall from height, road or workplace trauma, and severe associated injuries are prevalent, increasing the complexity of managing this patient group. The aim of this population-based study was to investigate predictors of mortality following severe pelvic ring fractures managed in an inclusive, regionalised trauma system. METHODS: Cases aged≥15 years from 1st July 2001 to 30th June 2008 were extracted from the population-based statewide Victorian State Trauma Registry for analysis. Patient demographic, prehospital and admission characteristics were considered as potential predictors of mortality. Multivariate logistic regression was used to identify predictors of mortality with adjusted odds ratios (AOR) and 95% confidence intervals (CI) calculated. RESULTS: There were 348 cases over the 8-year period. The mortality rate was 19%. Patients aged≥65 years were at higher odds of mortality (AOR 7.6, 95% CI: 2.8, 20.4) than patients aged 15-34 years. Patients hypotensive at the scene (AOR 5.5, 95% CI: 2.3, 13.2), and on arrival at the definitive hospital of care (AOR 3.7, 955 CI: 1.7, 8.0), were more likely to die than patients without hypotension. The presence of a severe chest injury was associated with an increased odds of mortality (AOR 2.8, 95% CI: 1.3, 6.1), whilst patients injured in intentional events were also more likely to die than patients involved in unintentional events (AOR 4.9, 95% CI: 1.6, 15.6). There was no association between the hospital of definitive management and mortality after adjustment for other variables, despite differences in the protocols for managing these patients at the major trauma services (Level 1 trauma centres). CONCLUSIONS: The findings highlight the importance of effective control of haemodynamic instability for reducing the risk of mortality. As most patients survive these injuries, further research should focus on long term morbidity and the impact of different treatment approaches.

Asunto(s)

RESUMEN

We report a case of compassionate use of a haemoglobin-based oxygen carrier in a severely injured Jehovah's Witness patient, for whom survival was considered unlikely. Severe anaemia and cardiac hypoxia were reversed after slow infusion of this agent. No vasoactive side effects were associated with the treatment, possibly due to the slow infusion, and the patient survived.

Asunto(s)