97 research outputs found
Extending health insurance in Ghana: effects of the National Health Insurance Scheme on maternity care
Background
There is considerable interest in exploring the potential of social health insurance in Africa where a number of countries are currently experimenting with different approaches. Since these schemes have been introduced recently and are continuously evolving, it is important to evaluate their effectiveness in the enhancement of health care utilization and reduction of out-of-pocket expenses for potential policy suggestions.
Objective
To investigate how the National Health Insurance Schemes (NHIS) in Ghana affects the utilization of maternal health care services and medical out-of-pocket expenses.
Methods
We used nationally-representative household data from the Ghana Demographic and Health Survey (GDHS). We analyzed the 2014 GDHS focusing on four outcome variables, i.e. antenatal check up, delivery in a health facility, delivery assisted by a trained person and out-of-pocket expenditure. We estimated probit and bivariate probit models to take into account the issue of self selection into the health insurance schemes.
Results
The results suggest that, also taking into account the issue of self selection into the health insurance schemes, the NHIS enrollment positively affects the probability of formal antenatal check-ups before delivery, the probability of delivery in an institution and the probability of being assisted during delivery by a trained person. On the contrary, we find that, once the issue of self-selection is taken into account, the NHIS enrollment does not have a significant effect on out-of-pocket expenditure at the extensive margin.
Conclusion
Since a greater utilization of health-care services has a strong positive effect on the current and future health status of women and their children, the health-care authorities in Ghana should make every effort to extend this coverage. In particular, since the results of the first step of the bivariate probit regressions suggest that the educational attainment of women is a strong determinant of enrollment, and those with low education and unable to read are less likely to enroll, information on the NHIS should be disseminated in ways that reach those with little or no education. Moreover, the availability of government health facilities in a region is associated with higher likelihood of enrollment in the NHIS. Accordingly, extending geographical access is an important strategy for expanding NHIS membership and improving access to health-care
Does the relative density of periarticular bone influence the failure pattern of intra-articular fractures?
Introduction: The architecture of joints almost certainly influences the nature of intra-articular fractures, and the concavity is much more likely to fail than the associated convexity. However, local differences in periarticular bone density potentially also plays a critical role. The purpose of this study was to investigate if there was any difference in periarticular bone density in intra-articular fractures between the two opposing joint surfaces, comparing the convexity to the concavity. Materials and methods: We retrospectively identified a series of 1003 intra-articular fractures of the hip, knee, and ankle; 129 of these patients had previously undergone CT scanning during their routine clinical assessment. Periarticular bone density was assessed using Hounsfield Units (HU) as a measure of the composite density of the adjacent bone. Bone density was compared between the opposite sides of each joint, to determine if a relationship exists between local bone density and the risk of articular surface fracture. Results: There was a statistically significant difference in density between the two opposing surfaces, with the convexity 19% more dense than the concavity (p = 0.0001). The knee exhibited the largest difference (55%), followed by the hip (18%); in the ankle, an inverse relationship was observed, and the concave surface was paradoxically denser (5%). There was no significant difference between those cases where the concavity failed in isolation compared to those where the convexity also failed (p = 0.28). Conclusion: When the results were pooled for all three joints, there was a statistically significant higher local bone density demonstrated on the convex side of an intra-articular fracture. However, while this relationship was clearly exhibited in the knee, this was less evident in the other two joints; in the ankle the reverse was true, and the local bone adjacent to the concavity was found to have greater density. This suggests local bone density plays only a minor role in determining the nature of intra-articular fractures
Reverse dynamisation: a modern perspective on Stephan Perren’s strain theory
The present review acknowledges the tremendous impact of Stephan Perren’s strain theory, considered with respect to the earlier contributions of Roux and Pauwels. Then, it provides further insight by examining how the concept of reverse dynamisation extended Perren’s theory within a modern context. A key factor of this more contemporary theory is that it introduces variable mechanical conditions at different time points during bone healing, opening the possibility of manipulating biology through mechanics to achieve the desired clinical outcome. The discussion focusses on the current state of the art and the most recent advances made towards optimising and accelerating bone regeneration, by actively controlling the mechanical environment as healing progresses. Reverse dynamisation utilises a very specific mechanical manipulation regimen, with conditions initially flexible to encourage and expedite early callus formation. Once callus has formed, the mechanical conditions are intentionally modified to create a rigid environment under which the soft callus is quickly converted to hard callus, bridging the fracture site and leading to a more rapid union. The relevant literature, principally animal studies, was surveyed to provide ample evidence in support of the effectiveness of reverse dynamisation. By providing a modern perspective on Stephan Perren’s strain theory, reverse dynamisation perhaps holds the key to tipping the balance in favour of a more rapid and reliable union when treating acute fractures, osteotomies, non-unions and other circumstances where it is necessary to regenerate bone
Does joint architecture influence the nature of intra-articular fractures?
Introduction: The architecture of joints has potentially the greatest influence on the nature of intra-articular fractures. We analysed a large number of intra-articular fractures with two aims: (1) to determine if the pattern of injuries observed supports our conjecture that the local skeletal architecture is an important factor and (2) to investigate whether associated dislocations further affect the fracture pattern. Methods: A retrospective study of intra-articular fractures over a 3.5-year period; 1003 joints met inclusion criteria and were analysed. Three independent investigators determined if fractures affected the convex dome, the concave socket, or if both joint surfaces were involved. Further review determined if a joint dislocation occurred with the initial injury. Statistical analysis was performed using a one-way frequency table, and the χ test was used to compare the frequencies of concave and convex surface fractures. The odds ratios (ORs) were calculated to establish the association between the frequencies of concave and convex surface fractures, as well as between dislocation and either fracture surface involvement. Results: Of the 1003 fractures analysed, 956 (95.3%) involved only the concavity of the joint; in 21 fractures (2.1%) both joint surfaces were involved; and in 26 fractures (2.6%) only the convexity was involved (χ = 1654.9, df = 2, p < 0.0001). As expected, the concavity was 20.8 times more likely to fail than the convexity (11.2-36.6, 95% CI). However, the risk of fracturing the convex surface was 18.6 times higher (9.8-35.2, 95% CI) in association with a simultaneous joint dislocation, compared to those cases without a joint dislocation. Conclusions: These results very strongly support the study hypotheses: the skeletal architecture of joints clearly plays a highly significant role in determining the nature of intra-articular fractures. Intra-articular fractures involving the convexity are much more likely to be associated with a concurrent joint dislocation. Crow
Development and validation of a computational model of the knee joint for the evaluation of surgical treatments for osteoarthritis
A three-dimensional (3D) knee joint computational model was developed and validated to predict knee joint contact forces
and pressures for different degrees of malalignment. A 3D computational knee model was created from high-resolution
radiological images to emulate passive sagittal rotation (full-extension to 658-flexion) and weight acceptance. A cadaveric
knee mounted on a six-degree-of-freedom robot was subjected to matching boundary and loading conditions. A ligamenttuning
process minimised kinematic differences between the robotically loaded cadaver specimen and the finite element
(FE) model. The model was validated by measured intra-articular force and pressure measurements. Percent full scale error
between FE-predicted and in vitro-measured values in the medial and lateral compartments were 6.67% and 5.94%,
respectively, for normalised peak pressure values, and 7.56% and 4.48%, respectively, for normalised force values. The knee
model can accurately predict normalised intra-articular pressure and forces for different loading conditions and could be
further developed for subject-specific surgical planning
Periprosthetic osseointegration fractures are infrequent and management is familiar
Aims Osseointegrated prosthetic limbs allow better mobility than socket-mounted prosthetics for lower limb amputees. Fractures, however, can occur in the residual limb, but they have rarely been reported. Approximately 2% to 3% of amputees with socket-mounted prostheses may fracture within five years. This is the first study which directly addresses the risks and management of periprosthetic osseointegration fractures in amputees. Methods A retrospective review identified 518 osseointegration procedures which were undertaken in 458 patients between 2010 and 2018 for whom complete medical records were available. Potential risk factors including time since amputation, age at osseointegration, bone density, weight, uni/bilateral implantation and sex were evaluated with multiple logistic regression. The mechanism of injury, technique and implant that was used for fixation of the fracture, pre-osseointegration and post fracture mobility (assessed using the K-level) and the time that the prosthesis was worn for in hours/day were also assessed. Results There were 22 periprosthetic fractures; they occurred exclusively in the femur: Two in the femoral neck, 14 intertrochanteric and six subtrochanteric, representing 4.2% of 518 osseointegration operations and 6.3% of 347 femoral implants. The vast majority (19/22, 86.4%) occurred within 2 cm of the proximal tip of the implant and after a fall. No fractures occurred spontaneously. Fixation most commonly involved dynamic hip screws (10) and reconstruction plates (9). No osseointegration implants required removal, the K-level was not reduced after fixation of the fracture in any patient, and all retained a K-level of = 2. All fractures united, 21 out of 22 patients (95.5%) wear their osseointegration-mounted prosthetic limb longer daily than when using a socket, with 18 out of 22 (81.8%) reporting using it for = 16 hours daily. Regression analysis identified a 3.89-fold increased risk of fracture for females (p = 0.007) and a 1.02-fold increased risk of fracture per kg above a mean of 80.4 kg (p = 0.046). No increased risk was identified for bilateral implants (p = 0.083), time from amputation to osseointegration (p = 0.974), age at osseointegration (p = 0.331), or bone density (g/cm2, p = 0.560; T-score, p = 0.247; Z-score, p = 0.312). Conclusion The risks and sequelae of periprosthetic fracture after press-fit osseointegration for amputation should not deter patients or clinicians from considering this procedure. Females and heavier patients are likely to have an increased risk of fracture. Age, years since amputation, and bone density do not appear influential
Combined autologous chondrocyte implantation (ACI) with supra-condylar femoral varus osteotomy, following lateral growth-plate damage in an adolescent knee: 8-year follow-up
We report the 8-year clinical and radiographic outcome of an adolescent patient with a large osteochondral defect of the lateral femoral condyle, and ipsilateral genu valgum secondary to an epiphyseal injury, managed with autologous chondrocyte implantation (ACI) and supracondylar re-alignment femoral osteotomy. Long-term clinical success was achieved using this method, illustrating the effective use of re-alignment osteotomy in correcting mal-alignment of the knee, protecting the ACI graft site and providing the optimum environment for cartilage repair and regeneration. This is the first report of the combined use of ACI and femoral osteotomy for such a case
Relationship between knee and ankle degeneration in a population of organ donors
<p>Abstract</p> <p>Background</p> <p>Osteoarthritis (OA) is a progressive degenerative condition of synovial joints in response to both internal and external factors. The relationship of OA in one joint of an extremity to another joint within the same extremity, or between extremities, has been a topic of interest in reference to the etiology and/or progression of the disease.</p> <p>Methods</p> <p>The prevalence of articular cartilage lesions and osteophytes, characteristic of OA, was evaluated through visual inspection and grading in 1060 adult knee/tali pairs from 545 cadaveric joint donors.</p> <p>Results</p> <p>Joint degeneration increased more rapidly with age for the knee joint, and significantly more knee joints displayed more severe degeneration than ankle joints from as early as the third decade. Women displayed more severe knee degeneration than did men. Severe ankle degeneration did not exist in the absence of severe knee degeneration. The effect of weight on joint degeneration was joint-specific whereby weight had a significantly greater effect on the knee. Ankle grades increasingly did not match within a donor as the grade of degeneration in either the left or the right knee increased.</p> <p>Conclusions</p> <p>Gender and body type have a greater effect on knee joint integrity as compared to the ankle, suggesting that knees are more prone to internal causative effects of degeneration. We hypothesize that the greater variability in joint health between joints within an individual as disease progresses from normal to early signs of degeneration may be a result of mismatched limb kinetics, which in turn might lead to joint disease progression.</p
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