Abstract
Introduction and aims: Flanged sockets have been in use since 1976.Experimental evidence has shown that they offer an advantage in terms of cement pressurization at the time of implantation. Radiological demarcation at the cement-bone interface has been shown to be significantly reduced in early radiographs with flanged sockets.The Opera Cup with its contoured flange containing a series of tangential rings was developed in Manchester.We present our early results with this cup.
Method: 140 patients had primary hip arthroplasty performed between July1997 and November 2000.
Ten had bilateral surgery.92 (66%) were female and 48 (34%) were male.The mean age at operation was 58 (range 34–90).The mean length of follow up was 50 months (range 36–76).
Standardised anteroposterior radiographs of the pelvis were compared at one year with the three to six year reviews.Radiological demarcation of the acetabular component was assessed using the Hodgkinson grading system by the senior author.
Results: 150 sockets were reviewed.62% had no demarcation at one year (grade 0).This figure fell to 56% at the three to six year review.Grade 1 changes were seen in 36% at one year rising to 41% at the three to six year review.
92% of sockets showed no increase in demarcation during the review period whilst 3% had developed evidence of radiological loosening with grades 2 to 4.
Conclusion: The development and progression of radiolucent lines are associated with aseptic socket loosening.Our results compare favourably with published studies.Long term follow up is needed to make more accurate comparisons.
Manchester Arthroplasty Unit, North Manchester General Hospital
The abstracts were prepared by Mr Peter Kay, Editorial Secretary. Correspondence should be addressed to British Hip Society, The Hip Centre, Wrightington Hospital, Appley Bridge, Wigan, Lancashire WN6 9EP.
