Abstract: A ball and socket interconnection capable of use in surgical retractor systems comprising a ball member and a socket member, the socket member defining an entry and being adapted to releasably receive the ball member such that when the ball member is received in the socket member it is capable of pivotal and rotational movement within the socket, the ball member having two spherical end surfaces between which is located an intermediate section, the spherical end surfaces having a radius of curvature greater than the radius of curvature of the entry and the intermediate section having a radius of curvature less than the radius of curvature of the entry, whereby the intermediate section renders the ball member releasably receivable in the socket member.