Charnley and Halley measured radiographic polyethylene wear in 72 THA sockets over 9-10 years using a magnification-corrected wire-marker technique. The study establishes the first quantitative wear benchmarks and examines whether wear rate changes over time and whether patient weight or activity influences wear.
The 22 mm femoral head and HMWP socket were Charnley's solution to the catastrophic Teflon failures of the early 1960s, but no one had measured how fast this new bearing actually wore in living patients over a decade.
This paper gives you the numbers you need for consent and surveillance: normal wear runs about 0.15 mm/year, slows down after the first 5 years, and 5 mm is the threshold where you start worrying about neck impingement and loosening.
When a young patient asks you how long their hip will last, this data is the foundation of your answer — and the finding that body weight and activity do not drive wear rate is still cited when counseling patients about returning to activity after THA.
The wire-marker magnification-correction technique introduced here became the methodologic template for all subsequent radiographic wear studies, and the observation that weight and activity are not the dominant wear drivers ultimately redirected research toward bearing surface materials, motivating the development of highly cross-linked polyethylene and alternative bearings.
Charnley and Halley measured radiographic polyethylene wear in 72 THA sockets over 9-10 years using a magnification-corrected wire-marker technique. The study establishes the first quantitative wear benchmarks and examines whether wear rate changes over time and whether patient weight or activity influences wear.
The 22 mm femoral head and HMWP socket were Charnley's solution to the catastrophic Teflon failures of the early 1960s, but no one had measured how fast this new bearing actually wore in living patients over a decade.
This paper gives you the numbers you need for consent and surveillance: normal wear runs about 0.15 mm/year, slows down after the first 5 years, and 5 mm is the threshold where you start worrying about neck impingement and loosening.
When a young patient asks you how long their hip will last, this data is the foundation of your answer — and the finding that body weight and activity do not drive wear rate is still cited when counseling patients about returning to activity after THA.
The wire-marker magnification-correction technique introduced here became the methodologic template for all subsequent radiographic wear studies, and the observation that weight and activity are not the dominant wear drivers ultimately redirected research toward bearing surface materials, motivating the development of highly cross-linked polyethylene and alternative bearings.