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Journal of Bone and Joint Surgery - British Volume, Vol 84-B, Issue 1,
83-87.
doi: 10.1302/0301-620X.84B1.11951 Copyright © 2002 by British Editorial Society of Bone and Joint Surgery Patterns of loosening of the glenoid componentJ. Nagels, MD, PhD, Student; E. R. Valstar, PhD, Post-doctoral Researcher; M. Stokdijk, MSc, PhD, Student; and P. M. Rozing, MD, PhD, Professor of Orthopaedics, Head of DepartmentOrthopaedic Laboratory, Department of Orthopaedics, Leiden University Medical Centre, B0-57 PO Box 9600, 2300 RC Leiden, The Netherlands. Correspondence should be sent to Dr J. Nagels. The incidence of loosening of a cemented glenoid componentin total shoulder arthroplasty, detected by means of radiolucent lines or positional shift of the component on true anteroposterior radiographs, has been reported to be between 0% and 44%. Radiolucent lines are, however, difficult to detect and to interpret because of the mobility of the shoulder girdle and the obliquity of the glenoid which hinder standardisation of radiographs. We examined radiolucencies around cemented glenoid components in 48 patients, with a mean follow-up of 5.3 years, and found progressive changes to be present predominantly at the inferior pole of the component. This may hold a clue for the mechanism of loosening of this implant. In five patients we performed an additional analysis of loosening of the glenoid component using digital roentgen stereophotogrammetric analysis (RSA). After three years, three of the five implants had loosened (migration 1.2 to 5.5 mm). In only one, with gross loosening, were the radiological signs consistent with the RSA findings. When traditional radiographs are used for assessment, the rate of early loosening is underestimated. We recommend that RSA be used for this. This article has been cited by other articles:
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