Are drains required following a routine primary total joint arthroplasty? Reply to comment by Al-Naser

We have attempted to determine the spatial orientation of the base of the superior articular process in relation to the centre of the pedicle and then measure the transverse and sagittal screw angles using this ideal pedicle screw entry point - the base of the superior articular process at the junction of the lateral one-third and medial two-thirds. The proposed advantages of this technique are the easily identifiable entry point, the well-defined transverse and sagittal screw angles and a very low incidence of medial and inferior pedicle violation.