(19)

(11)

EP 0 428 612 A1

(12)

(43) Date of publication: 29.05.1991 Bulletin 1991/22 (21) Application number: 89909785.0 (22) Date of filing: 10.08.1989

(51) International Patent Classification (IPC):  A61F 13/ 15( . ) A61F 13/ 56( . ) (86) International application number: PCT/GB1989/000914 (87) International publication number: WO 1990/001311 (22.02.1990 Gazette 1990/05)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 10.08.1988 GB 19880018997 (71) Applicant: SMITH & NEPHEW plc London WC2R 3BP (GB)	(72) Inventors: RAWLINGS, David Alan Elmdon, Essex CB11 4LT (GB) WOOD, Barbara Mary Birmingham, West Midlands B8 2HS (GB) (74) Representative: Cole, William Gwyn  Corporate Patents Department Smith and Nephew Research Limited Gilston Park Harlow Essex CM20 2RQ Harlow Essex CM20 2RQ (GB)