Radiographic assessment of ingrowth total shoulder arthroplasty

Sixty-two primary ingrowth total shoulder arthroplasties, performed between 1989 and 1992 and with a minimum radiographic and clinical follow-vp of 2 years or until the time of revision surgery (mean, 4.6 years), were reviewe d. To combine data on both the distribution and the thickness of periprosth etic lucency and change in component position, criteria were used to determ ine whether a component was radiographically "at risk" for clinical compone nt loosening. A glenoid component was "at risk" when a complete lucent line was present, some part of it being 1.5 mm or greater in width, or when 2 o f 3 or 3 of 3 independent observers identified migration or tilt of the com ponent. A humeral component was "at risk" when a lucent line 2 mm or greate r in width was present in 3 or more of 8 zones or when at least 2 of 3 inde pendent observers identified tilt or subsidence of the component. Four (6.5 %) of the 62 glenoid components and 6 (9.7%) of the 62 humeral components w ere judged to be "at risk." There were no identifiable patient, disease, or surgical characteristics associated with the development of an "at risk" g lenoid or humeral component. Currently despite this very favorable radiogra phic assessment, we reserve the use of a tissue ingrowth glenoid component fbr those patients with bone loss precluding bone cement fixation with a ke el type of implant. because advantages exist For use of a tissue ingrowth h umeral component, a press-fitted component with ingrowth surfaces is curren tly used unless bone deficiencies prevent secure fixation without cement.