Ce-TZP/Al2O3 nanocomposite as a bearing material in total joint replacement.

The objectives of this study were to investigate the biocompatibility, phase stability, and wear properties of a newly developed Ce-TZP/Al(2)O(3) nanocomposite, as compared to conventional ceramics, and to determine whether the new composite could be used as a bearing material in total joint prostheses. In tests of mechanical properties, this composite showed significantly higher toughness than conventional Y-TZP. For biocompatibility tests, cylindrical specimens of both the Ce-TZP/Al(2)O(3) nanocomposite and monolithic alumina were implanted into the paraspinal muscles of male Wistar rats. The tissue reactions were almost the same, and at 24 weeks after implantation, thin fibrous capsules with almost no inflammation were observed around both of them. There were no significant differences in membrane thickness between the two ceramics. After hydrothermal treatment in 121 degrees C vapor for 18 h, the new composite showed complete resistance to aging degradation, whereas Y-TZP showed a phase transformation of 25.3 vol% (initial 0.4%) to the monoclinic form. According to the results of pin-on-disk tests, the wear rates of Ce-TZP/Al(2)O(3) nanocomposite and alumina were 0.55 +/- 0.04 x 10(-7) and 2.12 +/- 0.37 x 10(-7)mm(3)/Nm, respectively. The results of this study suggest that the Ce-TZP/Al(2)O(3) nanocomposite is a promising alternative ceramic component for total joint replacement.

[Total inverted shoulder prosthesis and rotator cuff insufficiency: evaluation and determination of anatomical parameters predictive of good functional outcome in 21 shoulders]. / Prothèse totale inversée de l'épaule et insuffisance de la coiffe des rotateurs: évaluation et approche de paramètres anatomiques prédictifs d'une bonne fonctionnalité à propos de 21 cas.

OBJECTIVE: Evaluation of the functional results of the Delta 3 inverted shoulder prosthesis and determination of a radio-anatomical index predictive of best functional outcome. PATIENTS AND METHODS: Retrospective analysis of 19 patients (21 shoulders). Clinical (pain, satisfaction, amplitudes, Constant index) and radiological (acromio-epiphyseal distance) evaluation at a mean follow up of 13.6 months. RESULTS: Outcomes concerning pain, quality of life and Constant index were good and similar to other series. Few complications were observed. An increase of the acromio-epiphyseal distance of 33 to 50% compared to the non operated side is associated with a good functional result. CONCLUSION: Our results confirm those of other series and show that Delta 3 inverted prosthesis is an efficient therapeutic alternative in arthropathy with rotator cuff tears. Rehabilitation is fairly short and easy. The increase of the acromio-epiphyseal distance determines the tension of the deltoid muscle and could predict a favorable outcome.

Achieving functional integration: a continuum case study.

Inova Mount Vernon Hospital, a part of the Inova Health System in northern Virginia, has developed a plan to redesign its joint replacement service to better coordinate patient care across the entire continuum. The redesign incorporates services, such as presurgery therapy and patient education, registration and insurance activities, rehabilitation, and home care, into an existing acute care joint replacement clinical pathway to create a continuum of care. To encourage the provider partners to integrate the joint replacement service, Inova Mount Vernon Hospital developed new types of clinical, economic, and service outcome measurements to view episodes of care from a system perspective. These measurements will be used to assess the success of the functional integration effort.