DeLee and Charnley set out to measure how often a radiolucent line forms between cement and acetabular bone around cemented Charnley sockets, how it changes over time, and whether it signals clinical failure.
Prospective series of 141 cemented Charnley hips with annual radiographs, mean follow‑up 10.1 years.
Methods
Design
Prospective series
Annual radiographs to final state
Patients
141 Charnley low‑friction arthroplasties
Mean follow‑up 10.1 years
18 bilateral operations
Basis
Distribution of the lucent line around the socket (Types I to III)
Widest width of the line, in four bands
Socket migration by subsidence along the socket axis or tilting
Key Findings
Demarcation of some degree developed in 69.5% of hips (98 of 141), and 44 hips showed none throughout the 10‑year study.
Socket migration occurred in 13 hips, which was 9.2% of the series and 13% of hips with demarcation.
Mean d'Aubigné-Postel pain grade was 5.9 both in the 85 hips with demarcation but no migration and in the 44 hips without demarcation.
Demarcation first appeared within the first postoperative year in 71.1% of the 98 affected hips, and in 75 of the 85 non‑migrating hips (88%) it no longer changed after 6 years.
Operation notes recorded mechanical defects that could help explain migration in 6 of the 13 migrating hips, and low‑grade deep sepsis was present in 3.
Demarcation was significantly more frequent in rheumatoid arthritis than in osteoarthritis.
Board pearl
In DeLee and Charnley's system, Type III means the lucent line runs around the entire cement‑bone circumference of the socket.
Authors' conclusion
The fact that nearly 30 per cent of cases showed no demarcation even after 10 years supports the idea that there is no fundamental defect in the principle of employing cement in the acetabulum. Better surgical technique may increase the number of cases showing no demarcation.
DeLee and Charnley set out to measure how often a radiolucent line forms between cement and acetabular bone around cemented Charnley sockets, how it changes over time, and whether it signals clinical failure.
Prospective series of 141 cemented Charnley hips with annual radiographs, mean follow‑up 10.1 years.
Methods
Design
Prospective series
Annual radiographs to final state
Patients
141 Charnley low‑friction arthroplasties
Mean follow‑up 10.1 years
18 bilateral operations
Basis
Distribution of the lucent line around the socket (Types I to III)
Widest width of the line, in four bands
Socket migration by subsidence along the socket axis or tilting
Key Findings
Demarcation of some degree developed in 69.5% of hips (98 of 141), and 44 hips showed none throughout the 10‑year study.
Socket migration occurred in 13 hips, which was 9.2% of the series and 13% of hips with demarcation.
Mean d'Aubigné-Postel pain grade was 5.9 both in the 85 hips with demarcation but no migration and in the 44 hips without demarcation.
Demarcation first appeared within the first postoperative year in 71.1% of the 98 affected hips, and in 75 of the 85 non‑migrating hips (88%) it no longer changed after 6 years.
Operation notes recorded mechanical defects that could help explain migration in 6 of the 13 migrating hips, and low‑grade deep sepsis was present in 3.
Demarcation was significantly more frequent in rheumatoid arthritis than in osteoarthritis.
Board pearl
In DeLee and Charnley's system, Type III means the lucent line runs around the entire cement‑bone circumference of the socket.
Authors' conclusion
The fact that nearly 30 per cent of cases showed no demarcation even after 10 years supports the idea that there is no fundamental defect in the principle of employing cement in the acetabulum. Better surgical technique may increase the number of cases showing no demarcation.