Increased antibiotic release and equivalent biomechanics of a spacer cement without hard radio contrast agents.

We compared a novel calcium carbonate spacer cement (Copal® spacem) to well-established bone cements. Electron microscopic structure and elution properties of the antibiotics ofloxacin, vancomycin, clindamycin, and gentamicin were examined. A knee wear simulator model for articulating cement spacers was established. Mechanical tests for bending strength, flexural modulus, and compressive and fatigue strength were performed. The electron microscopic analysis showed a microporous structure of the spacer cement, and this promoted a significantly higher and longer antibiotic elution. All spacer cement specimens released the antibiotics for a period of up to 50days with the exception of the vancomycin loading. The spacer cement showed significantly less wear scars and fulfilled the ISO 5833 requirements. The newly developed spacer cement is a hydrophilic antibiotic carrier with an increased release. Cement without hard radio contrast agents can improve tribological behaviour of spacers, and this may reduce reactive wear particles and abrasive bone defects.

Scoliosis and congenital anomalies associated with Klippel-Feil syndrome types I-III.

STUDY DESIGN: This investigation was aimed at characterizing anomalies and syndromes associated with Klippel-Feil syndrome in a large group of patients. The authors evaluated the clinical and radiographic features, documented the associated anomalies, and registered the type of treatment. OBJECTIVE: The anomalies or syndromes and the development of scoliosis were correlated to the type of Klippel-Feil syndrome. MATERIAL AND METHODS: In a cross-sectional study, the authors reviewed data from 57 patients with Klippel-Feil syndrome treated over 25 years at the Department for Orthopedics of the University of Heidelberg. The patients (17 males and 40 females; average age of the first contact, 12 years) were classified into three types according to the description of Feil in 1919. RESULTS: Klippel-Feil syndrome Type I (fusion of cervical and upper thoracic vertebra with synostosis) and Type II (isolated cervical spine) corresponded to 40% and 47% of patients, respectively. Type III (cervical vertebra associated with lower thoracic or upper lumbar fusion) was displayed in 13% of the patients only. The authors found a variety of combinations of Klippel-Feil syndrome and other anomalies in the patients examined in this study, with 67% of the patients characterized by an association with other disorders or syndromes. Of the patients, 70% showed scoliosis. Its degree depended on the type of Klippel-Feil syndrome. Scoliosis in Type I correlated with 31 degrees (Cobb angle), in Type III with 23 degrees, and in Type II with 9 degrees only. Thus, Type II, with isolated cervical fusion, shows a low risk for scoliosis. CONCLUSION: This study increases knowledge of a wide range of anomalies and syndromes identified in association with Klippel-Feil syndrome. A special finding of the study was a correlation between the degree of scoliosis and Klippel-Feil syndrome Types I, II, and III.