the present invention is directed to a surgical drill guide . the drill guide may include a first drill guide body having a distal end for placement substantially adjacent a bone , a second drill guide body slidable with respect to the first drill guide body and having a proximal end for contacting a portion of a drill bit , a handle associated with at least one of the first drill guide body and the second drill guide body , and a detent mechanism for releasably retaining the position of the first drill guide body with respect to the second drill guide body in predefined increments . additionally or alternatively , the drill guide may include a locking member movable between a first position where it substantially prevents sliding of the second drill guide body with respect to the first drill guide body , and a second position where it permits sliding of the second drill guide body with respect to the first drill guide body . the locking member may be resiliently biased to the first position . other features for improving the drill guide are disclosed and claimed as well .