SA Orthopaedic Journal
On-line version ISSN 2309-8309
GROBBELAAR, CJ; WEBER, FA and DU PLESSIS, TA. Thirty three years of clinical experience with crosslinking of polyethylene in cemented total hip replacement. SA orthop. j. [online]. 2011, vol.10, n.1, pp. 42-48. ISSN 2309-8309.
In response to the realisation, in the early 70s, that polyethylene debris emerged as an important cause of osteolysis and implant looseness, a new hip implant was designed and developed in Pretoria. Although this was a Charnley lookalike, one of its most important goals was to reduce polyethylene wear and particle disease to the absolute minimum. A programme to gamma-crosslink pre-manufactured polyethylene cups was undertaken under the expert guidance of the third author. The process was unique in the sense that surface crosslinking was augmented in the presence of acetylene as mediating gas in the crosslinking chamber. In vitro mechanical tests were promising and were published extensively locally and abroad. From 1977 to 1983 a cohort of 2200 hip replacements was performed by the first and second authors combine. This publication acknowledges the Johannesburg cohort, but will focus on the 1775 cases performed by the Pretoria practice, with valuable co-operation and comparisons with the Johannesburg group. From our 1775 operations, we were able to follow up 272 hips at 10 years, and 97 operations for 10-33 years (mean 20.2 years) and this follow-up process is still ongoing. It was concluded that there was an almost seven to eight times improvement in the polyethylene cup wear, from the international figure of ± 0.1mm per year down to 0.015 mm per year. Not only the longevity, but also the arthroplasty quality was greatly improved. Polyethylene crosslinking has now reached international acceptance in the written as well as the electronic press.