[Long-term results in total knee arthroplasty. A meta-analysis of revision rates and functional outcome]. / Langzeitergebnisse in der Knieendoprothetik : Metaanalyse zu Revisionsrate und funktionellem Ergebnis.

BACKGROUND: Total knee arthroplasty (TKA) is one of the most common procedures in orthopedic surgery and clinical success can be characterized by the revision rate and improvement of function. To quantify both characteristics two independent meta-analyses have been performed. MATERIALS AND METHODS: A search in Medline provided a total of 96 studies on revision rates and 63 studies with functional results with a minimum follow-up of 5 years. RESULTS: A total of 911 revisions among 20,873 TKAs were identified corresponding to a meta-revision rate of 4.4% after a mean follow-up of 10.7 years. Most common causes for revision were aseptic loosening (31%), infection (23%), polyethylene wear (16%) and patellar problems (14%). Revision rates were higher in younger patients (7.0% <60 years at time of operation, 5.0% between 60 to 70 years and 2.2% >70 years), after cementless TKA (8.3% cementless versus 3.6% cemented) and in studies with a higher rate of patients with rheumatoid arthritis. The second meta-analysis revealed a meta-improvement based on the Knee Society Knee Score of 51.3%, for the Knee Society Function Score of 30.6%, for the Hospital for Special Surgery Score of 36.1% and for the New Jersey Orthopedic Hospital Knee Evaluation System of 33.6%. CONCLUSION: TKA is a successful treatment for osteoarthritis of the knee with an expectable revision rate of less than 5% within 10 years and a long-lasting functional improvement of more than 30% in any assessment score.

Harmonisation of rat fetal skeletal terminology and classification. Report of the Third Workshop on the Terminology in Developmental Toxicology. Berlin, 14-16 September 2000.

The initial efforts of the Federal Institute for Health Protection of Consumers and Veterinary Medicine (BgVV) and the Free University of Berlin to standardise terminology in the field of developmental toxicology began in 1995. Procedures were undertaken to harmonise the terminology used by the International Federation of Teratology Societies (IFTS) and the International Programme on Chemical Safety (IPCS). This article reflects these activities and is a report on the Third Workshop on the Terminology in Developmental Toxicology held in September 2000. This Workshop served as a forum to discuss the results of a survey on the classification of skeletal anomalies that had been previously sent to scientists active in the field. Although high agreement was reached among the evaluators for several terms, the use of a number of terms was rather variable. Therefore, the discussions at the workshop among the experts from research institutions, regulatory agencies, and industry were mainly focussed on those terms for which there was disagreement and/or uncertainties and the possible reasons. Pictures provided by the participants for the illustration of "grey zone" anomalies constituted the basis for detailed discussions. In many of the cases with lower agreement, decisions were facilitated by the provision of the corresponding picture. The main reasons for lower agreement were imprecise terms, insufficient knowledge on postnatal consequences, theoretical terms that are unlikely to occur in isolation, and the possibility of observing a range of severity that might be decisive for the classification of either a malformation or variation. The attendees concluded that "grey-zone" anomalies will never disappear completely and that for the assessment, the grade of severity and/or the frequency of the observation can be decisive for the terminology chosen. A Joint IPCS/IFTS Project was proposed to further consensus of terminology and classification and to link these anomalies to pictures at different skeletal sites. In order to support the harmonisation of regulatory decisions, it was proposed to establish a "Clearinghouse" System under the umbrella of the IPCS. The Clearinghouse could be contacted either by the regulatory authorities or by any company to clarify their queries, particularly with regard to registration or authorisation processes. Finally, it was recommended to also carry out a similar survey on "soft tissue anomalies" and "external findings." The results of this survey will be discussed at a Joint IPCS/IFTS Workshop in Berlin in 2002.