Posted as supplied by author.

Participating Units Contributors:

Each participating unit had:

Surgical collaborators, responsible for recruiting and operating on patients.

A trial research therapist, responsible for recruitment and organisation of patients, admissions and administration at al local.

Physiotherapy collaborators responsible for organising the rehabilitation programmes and treating patients.

Woodend Hospital, Aberdeen: J Burt, J. Easton, M Stocker, D Wardlaw;

BUPA Hartswood Hospital, Brentwood: E Gampell, A Gardner;

Hinchingbrooke Hospital, Huntingdon: A Taylor, A Wojcik;

The Ipswich Hospital, Ipswich: A Garner, J Gooderham, J Powell, D Sharp, H Vernau, J Wright;

Middlesbrough General Hospital, Middlesbrough: C Greenough, A. Jones, S. Nicholson, S Papastefanou, A Wilkin;

Queen�s Medical Centre, Nottingham; E Bevan-Davies, B Freeman, R. Goodwin, M Grevitt, J Hegarty, R Kasim, S Mehdian, R Mulholland, H Prince, A Wainwright, J Webb;

Robert Jones & Agnes Hunt Orthopaedic Hospital, Oswestry: C Darley, S Eisenstein, C Evans, E Jones;

Nuffield Orthopaedic Centre, Oxford: K Barker, A Allen, J Fairbank, B Swietalska, J Wilson-MacDonald;

Royal Berkshire Hospital, Reading: R Marshall, A Sandall;

St. Albans City Hospital, St. Albans: S Crowley, P Dyson, S Harvey, E McWhirter; Northern General Hospital, Sheffield: J Getty, K Grafton, K Jones, L Yorke;

Royal National Orthopaedic Hospital, Stanmore: J Johnson, H Nafis, M Sullivan;

North Staffordshire Hospital, Stoke-on-Trent: J Dove, G Evans, V Jasani;

Sunderland Royal Hospital, Sunderland: A Cross, G Gatenby;

Princess Margaret Hospital, Swindon: F. Cook, A Fogg, M Foy, J Hay

The MRC steering committee included, R Collins, J Fairbank, H Frost, W Gillespie (1st Chairman), A Grant, A Gray, P Gregg (2nd Chairman), M Jayson, R Johnstone, J Klaber-Moffett, and W Maton-Howarth.