DeLee and Charnley prospectively followed 141 cemented Charnley total hip arthroplasties over a mean of 10.1 years. They asked how often radiolucent lines appear at the acetabular cement-bone interface, how they evolve, and whether they predict clinical failure. From this work came the three-zone classification system that remains the standard language for describing acetabular interface changes.
When you see a radiolucent line around a cemented acetabular component, resist the instinct to revise. This paper established that demarcation is present in nearly 70% of well-functioning cemented sockets — the line itself is not the problem.
What matters is whether it is progressive. Demarcation that stabilizes by 6 years in an asymptomatic patient is almost never a revision indication. The two findings that should change your management are progressive widening after a period of stability and documented migration of the socket.
When migration is present, review the operative record for the identifiable culprits DeLee and Charnley catalogued: deficient acetabular walls, excessive reaming, osteoporotic bone, and low-grade infection. These were present in 9 of 13 migrating cases.
The three-zone system this paper introduced became the universal substrate for subsequent loosening research, including Hodgkinson et al.'s 1988 operative correlation study confirming that complete progressive radiolucency. Not a partial or stable line. Predicts intraoperative loosening. Apply these zones whenever you dictate a postoperative hip radiograph report.
DeLee and Charnley prospectively followed 141 cemented Charnley total hip arthroplasties over a mean of 10.1 years. They asked how often radiolucent lines appear at the acetabular cement-bone interface, how they evolve, and whether they predict clinical failure. From this work came the three-zone classification system that remains the standard language for describing acetabular interface changes.
When you see a radiolucent line around a cemented acetabular component, resist the instinct to revise. This paper established that demarcation is present in nearly 70% of well-functioning cemented sockets — the line itself is not the problem.
What matters is whether it is progressive. Demarcation that stabilizes by 6 years in an asymptomatic patient is almost never a revision indication. The two findings that should change your management are progressive widening after a period of stability and documented migration of the socket.
When migration is present, review the operative record for the identifiable culprits DeLee and Charnley catalogued: deficient acetabular walls, excessive reaming, osteoporotic bone, and low-grade infection. These were present in 9 of 13 migrating cases.
The three-zone system this paper introduced became the universal substrate for subsequent loosening research, including Hodgkinson et al.'s 1988 operative correlation study confirming that complete progressive radiolucency. Not a partial or stable line. Predicts intraoperative loosening. Apply these zones whenever you dictate a postoperative hip radiograph report.