Medium term outcomes of primary and revision Coonrad-Morrey total elbow replacement

Background:

Total elbow replacement (TER) is indicated in inflammatory arthritis, osteoarthritis and fractures that are not amenable to reconstruction. There is no series in literature, to the best of our knowledge, regarding the results of revision of the Souter-Strathclyde prosthesis (SSP) to the Coonrad-Morrey prosthesis (CMP). The aim of this study is to present the medium term results of primary CMP total elbow replacement and revision of the SSP to CMP.

Materials and Methods:

50 primary CMPs (Group I) and 11 revision CMPs (Group II) were included in the study. Demographic, operative, followup and radiological data were analysed. The indication for revision of the primary implant was peri-prosthetic fracture in six cases, aseptic loosening in four cases and instability in one case.

Results:

The mean age in Group I was 67.28 ± 12.45 years and in Group II was 57.09 ± 11.25 years. The mean period of followup was 8.08 ± 2.95 years and 7.46 ± 2.39. There was a significant improvement in range of motion and pain in both groups. The complications seen were nerve palsy, infection, fractures and heterotopic ossification. The 5-year survival rate in Group I was 94%. The results were good in 36 elbows, fair in 8 elbows and poor in 5 elbows. In Group II, the results were good in 8 elbows, fair in 2 elbows and poor in 1 elbow. The complications seen were nerve palsy, fractures and heterotopic ossification.

Discussion:

Primary CMP TER provides a functionally useful range of movement of 100° which is enough to perform most activities of daily living. It also produces a pain free and stable joint. Similar results are achieved after revision of the SSP to CMP. The unique toggle-hinge mechanism of articulation provides inherent stability and good survivorship.

Conclusion:

Semiconstrained prostheses like CMP provide good functional results and survivorship and are the implant of choice in both primary and revision total elbow replacements.     

Oral controlled release formulation of diclofenac sodium by microencapsulation with ethyl cellulose

The aim of this study was to formulate and evaluate microencapsulated controlled release preparations of diclofenac sodium (DFS) using different proportions of ethyl cellulose (EC) as the retardant material to extend the release. The formulated microcapsules were then compressed into tablets to obtain controlled release oral formulations. Phase separation-coacervation technique was employed to prepare microcapsules of DFS using different proportions of EC in cyclohexane. Physical characteristics of microcapsules and their tablets, in vitro release pattern of the designed microcapsules and their tablets prepared from them were studied using USP dissolution apparatus (USP 2000) type 2 (paddle method) in triple distilled water. The prepared microcapsules were white, free flowing and spherical in shape, with the particle size varying from 49.94-52.72 #119 m. The duration of DFS release from microcapsules was found to be directly proportional to the proportion of EC and, thus, coat thickness. All tablets were of good quality with respect to appearance, drug content uniformity, hardness, weight variation, friability and thickness uniformity. In vitro release study of the tabletted microcapsules in triple distilled water showed a zero order release kinetics and extended release beyond 24 h. A good correlation was obtained between drug release (t 60) and proportion of EC in the microcapsules. In the case of tabletted microcapsules, very good correlation could be established between t 60, proportion of EC, weight of the tablets and between release rate constant (K) and proportion of EC. All the formulations were highly stable and possessed reproducible release kinetics across the batches.     

Comparison of re-exposure rates of intraoral radiographs between dental students and trained dental assistants in an oral and maxillofacial radiology clinic

OBJECTIVE: To compare the re-exposure rates of dental radiographs taken over a period of 1 year between dental students and trained dental assistants at a university-based oral and maxillofacial radiology clinic. METHODS: Detailed records of the number and type of intraoral radiographs taken by the students and staff members and the number of re-exposures that were required from July 2003 to July 2004 were used. Statistical analyses were performed on the data. RESULTS: A chi2 test showed that re-exposure rates of radiographic series between students and staff were statistically different. When comparing the students' re-exposure rates during each of the four quarters of their radiology rotation, one-way analysis of variance test showed that the results were not statistically significant for reduction in the number of re-exposures over the entire year. CONCLUSIONS: There were significant differences in the re-exposure rates between staff dental assistants and students. Film re-exposure rates for the students during the four quarters were expected to decrease with time. Instead, the consistency of the re-exposure rates of the students during the four quarters demonstrates the need to recognize why the students did not perform better as the year progressed. The percentage of films that needed to be re-exposed by either group (students or the staff dental assistants) was not extremely high.     

RHC 3024: antiallergic activity in vitro and comparison with disodium cromoglycate and other antiallergic agents

RHC 3024 has been investigated for its antiallergic activity in three in vitro models of anaphylaxis. We have also compared its activity profile in these models with that of disodium cromoglycate (DSCG) and other antiallergic agents. As an inhibitor of antigen-induced release of histamine from rat mast cells RHC 3024 was 4 times more potent than DSCG. In the same model the activity profile of RHC 3024 was identical to that of DSCG in the following respects: loss of inhibitory activity with increasing preincubation time, reversibility of the inhibition, tachyphylaxis and cross-tachyphylaxis to each other and inability to inhibit histamine release stimulated by Ca++ ionophore, dextran/phosphatidyl serine and compound 48/80. Both drugs had no effect in the other two models, IgG1-mediated histamine release from guinea pig lung and anti-IgE-induced histamine release from human basophils. We conclude: (1) RHC 3024 is a potent inhibitor of mediator release with a mechanism of action similar to that of DSCG, M&B 22,948, PRD-92-Ea and AH-7725 and (2) the in vitro activity profiles of proxicromil, doxantrazole, ICI 74,917 and WY-16,922 are different from DSCG and RHC 3024.