Background: The progress of radiolucent lines (RLs) around the stems of cementless hip endoprostheses and their implications for implant survival are unclear.
Patients and methods: 150 consecutive total hip replacements (THRs) were performed between January and July 1993. The presence and development of RLs and osteolyses were monitored with a standardized special radiographic technique, and the results were compared at 6 and 10 years of follow-up in 95 patients.
Results: At 6 years, RLs were detectable in 43 of 95 patients. RLs with an extension of 50% of the respective zone were present in 35 patients, almost all in Gruen zones 1 and 7. 2 patients presented with osteolysis. At 10 years, the RLs were almost identical--both in number and thickness. Only 1 additional osteolytic lesion had developed; no cup osteolyses were detected, and there was no significant polyethylene wear.
Interpretation: The RLs detected at 6 years were virtually unchanged at 10 years. As they did not progress, they would not jeopardize implant stability. However, the osteolyses seen in 3 patients emphasize the importance of follow-up examinations.