Spherical kinematic joint

An improved spherical joint prosthesis for providing three degrees of rotational movement between two bones, comprising:

• a first component for engaging one of said two bones and providing internally a first seat;
• a second component for engaging the other of said two bones and including a neck and a spherical head;
• a bearing insert comprising a generally semi-hemispherically shaped primary bearing segment having a forward portion and a separate generally annularly shaped, radially split collar having a rearward portion, said primary bearing segment and said collar cooperatively providing internally a second seat having an opening for receiving said head;
• said forward and rearward portions provided respectively with complementarily shaped mating means, said mating means form said primary bearing segment and said collar into a sub-assembly whereupon engagement of said complementarily shaped mating means allows said collar to expand radially outwardly permitting said head to be inserted through said opening and once said head is received in said second seat said collar is able to contract radially inwardly without separation from said primary segment prior to and during assembly with said first and second component;
• said bearing insert and said first component provided with cooperative retaining means for retaining said bearing insert within said first seat upon insertion of said bearing insert into said first component;
• and
• upon said head being received within said second seat with said neck extending through said opening, said bearing insert for being received and retained within said first seat with said first component confining said head within said second seat whereby said rotational movement between said two bones is permitted, said bearing insert providing an overlap angle for preventing dislocation of said head from said bearing insert during said rotational movement.