An instrument fixation device comprising: a retaining ring; a ball joint having an outer surface and disposed within and moveable relative to the retaining ring, the ball joint defining a channel therethrough, wherein the ball joint includes two or more lobes and the channel is a deformable channel, and wherein the ball joint has an unsecured configuration in which the deformable channel is undeformed and a secured configuration in which the deformable channel is deformed; and a locking mechanism including a locking sleeve at least partially disposed within the retaining ring and engagable with the outer surface of the ball joint, and a lock including an engagement portion which engages the locking sleeve to cause the locking sleeve to engage the outer surface of the ball joint, to cause the locking mechanism to have: an unlocked position wherein the ball joint is free to move within the retaining ring, a first locked position, wherein the locking sleeve engages the outer surface of the ball joint to fix the ball joint relative to the retaining ring in which the ball joint has the unsecured configuration in which the channel is configured to slidably and rotatably receive a surgical instrument (120, I), and a second locked position wherein the locking sleeve engages the outer surface of the ball joint to fix the ball joint relative to the retaining ring and urges the lobes inwards to deform the deformable channel to the secured configuration in which the channel is configured to fix a surgical instrument relative to the ball joint. a retaining ring; a ball joint having an outer surface and disposed within and moveable relative to the retaining ring, the ball joint defining a channel therethrough, wherein the ball joint includes two or more lobes and the channel is a deformable channel, and wherein the ball joint has an unsecured configuration in which the deformable channel is undeformed and a secured configuration in which the deformable channel is deformed; and a locking mechanism including a locking sleeve at least partially disposed within the retaining ring and engagable with the outer surface of the ball joint, and a lock including an engagement portion which engages the locking sleeve to cause the locking sleeve to engage the outer surface of the ball joint, to cause the locking mechanism to have: an unlocked position wherein the ball joint is free to move within the retaining ring, a first locked position, wherein the locking sleeve engages the outer surface of the ball joint to fix the ball joint relative to the retaining ring in which the ball joint has the unsecured configuration in which the channel is configured to slidably and rotatably receive a surgical instrument (120, I), and a second locked position wherein the locking sleeve engages the outer surface of the ball joint to fix the ball joint relative to the retaining ring and urges the lobes inwards to deform the deformable channel to the secured configuration in which the channel is configured to fix a surgical instrument relative to the ball joint. a locking sleeve at least partially disposed within the retaining ring and engagable with the outer surface of the ball joint, and a lock including an engagement portion which engages the locking sleeve to cause the locking sleeve to engage the outer surface of the ball joint, to cause the locking mechanism to have: an unlocked position wherein the ball joint is free to move within the retaining ring, a first locked position, wherein the locking sleeve engages the outer surface of the ball joint to fix the ball joint relative to the retaining ring in which the ball joint has the unsecured configuration in which the channel is configured to slidably and rotatably receive a surgical instrument (120, I), and a second locked position wherein the locking sleeve engages the outer surface of the ball joint to fix the ball joint relative to the retaining ring and urges the lobes inwards to deform the deformable channel to the secured configuration in which the channel is configured to fix a surgical instrument relative to the ball joint.