Evaluation of subsidence, chondrocyte survival and graft incorporation following autologous osteochondral transplantation

Contains fulltext : 95878.pdf (publisher's version ) (Open Access)PURPOSE: The aim of this study was to evaluate subsidence tendency, surface congruency, chondrocyte survival and plug incorporation after osteochondral transplantation in an animal model. The potential benefit of precise seating of the transplanted osteochondral plug on the recipient subchondral host bone ('bottoming') on these parameters was assessed in particular. METHODS: In 18 goats, two osteochondral autografts were harvested from the trochlea of the ipsilateral knee joint and inserted press-fit in a standardized articular cartilage defect in the medial femoral condyle. In half of the goats, the transplanted plugs were matched exactly to the depth of the recipient hole (bottomed plugs; n = 9), whereas in the other half of the goats, a gap of 2 mm was left between the plugs and the recipient bottom (unbottomed plugs; n = 9). After 6 weeks, all transplants were evaluated on gross morphology, subsidence, histology, and chondrocyte vitality. RESULTS: The macroscopic morphology scored significantly higher for surface congruency in bottomed plugs as compared to unbottomed reconstructions (P = 0.04). However, no differences in histological subsidence scoring between bottomed and unbottomed plugs were found. The transplanted articular cartilage of both bottomed and unbottomed plugs was vital. Only at the edges some matrix destaining, chondrocyte death and cluster formation was observed. At the subchondral bone level, active remodeling occurred, whereas integration at the cartilaginous surface of the osteochondral plugs failed to occur. Subchondral cysts were found in both groups. CONCLUSIONS: In this animal model, subsidence tendency was significantly lower after 'bottomed' versus 'unbottomed' osteochondral transplants on gross appearance, whereas for histological scoring no significant differences were encountered. Since the clinical outcome may be negatively influenced by subsidence, the use of 'bottomed' grafts is recommended for osteochondral transplantation in patients

Expression of matrix metalloproteinase-1 (MMP-1) in Wistar rat's intervertebral disc after experimentally induced scoliotic deformity

<p>Abstract</p> <p>Introduction</p> <p>A scoliotic deformity on intervertebral discs may accelerate degeneration at a molecular level with the production of metalloproteinases (MMPs). In the present experimental study we evaluated the presence of MMP-1 immunohistochemically after application of asymmetric forces in a rat intervertebral disc and the impact of the degree of the deformity on MMP-1 expression.</p> <p>Material-Method</p> <p>Thirty female Wistar rats (aged 2 months old, weighted 200 ± 10 grams) were used. All animals were age, weight and height matched. A mini Ilizarov external fixator was applied at the base of a rat tail under anaesthesia in order to create a scoliotic deformity of the intervertebral disc between the 9^thand 10^thvertebrae. Rats were divided into three groups according to the degree of the deformity. In group I, the deformity was 10°, in group II 30° and in group III 50°. The rats were killed 35 days after surgery. The discs were removed along with the neighbouring vertebral bodies, prepared histologically and stained immunohistochemically. Immunopositivity of disc's cells for MMP-1 was determined using a semi-quantitative scored system.</p> <p>Results</p> <p>MMP-1 immunopositivity was detected in disc cells of annulus fibrosus of all intervertebral disc specimens examined. The percentage of MMP-1 positive disc cells in annulus fibrosus in group I, II and III were 20%, 43% and 75%, respectively. MMP-1 positivity was significantly correlated with the degree of the deformity (p < 0,001). An increase of chondrocyte-like disc cells was observed in the outer annulus fibrosus and at the margin of the intervertebral disc adjacent to the vertebral end plates. The difference in the proportion of MMP-1 positive disc cells between the convex and the concave side was statistically not significant in group I (p = 0,6), in group II this difference was statistically significant (p < 0,01). In group III the concave side showed a remarkable reduction in the number of disc's cells and a severe degeneration of matrix microstructure.</p> <p>Conclusion</p> <p>The present study showed that an experimentally induced scoliotic deformity on a rat tail intervertebral disc results in over-expression of MMP-1, which is dependent on the degree of the deformity and follows a dissimilar distribution between the convex and the concave side.</p

Professional Service Utilisation among Patients with Severe Mental Disorders

<p>Abstract</p> <p>Background</p> <p>Generally, patients with serious mental disorders (SMD) are frequent users of services who generate high care-related costs. Current reforms aim to increase service integration and primary care for improved patient care and health-care efficiency. This article identifies and compares variables associated with the use by patients with SMD of services offered by psychiatrists, case managers, and general practitioners (GPs). It also compares frequent and infrequent service use.</p> <p>Method</p> <p>One hundred forty patients with SMD from five regions in Quebec, Canada, were interviewed on their use of services in the previous year. Patients were also required to complete a questionnaire on needs-assessment. In addition, data were collected from clinical records. Descriptive, bivariate, and multivariate analyses were conducted.</p> <p>Results</p> <p>Most patients used services from psychiatrists and case managers, but no more than half consulted GPs. Most patients were followed at least by two professionals, chiefly psychiatrists and case managers. Care access, continuity of care, and total help received were the most important variables associated with the different types of professional consultation. These variables were also associated with frequent use of professional service, as compared with infrequent service use. In all, enabling factors rather than need factors were the core predictors of frequency of service utilisation by patients with SMD.</p> <p>Conclusion</p> <p>This study reveals that health care system organisation and professional practice - rather than patient need profiles - are the core predictors of professional consultation by patients with SMD. The homogeneity of our study population, i.e. mainly users with schizophrenia, recently discharged from hospital, may partly account for these results. Our findings also underscored the limited involvement of GPs in this patient population's care. As comorbidity is often associated with serious mental disorders, closer follow-up by GPs is needed. Globally, more effort should be directed at increasing shared-care initiatives, which would enhance coordination among psychiatrists, GPs, and psychosocial teams (including case managers). Finally, there is a need to increase awareness among health care providers, especially GPs, of the level of care required by patients with disabling and serious mental disorders.</p