Reply to “Comments on ‘Posterior Subaxial Cervical Spine Screw Fixation: A Review of Techniques’ by Joaquim et al”

We thank the authors for their interest in our article. We strongly agree that the differences in the standard techniques of lateral mass screw fixation based on numeric values are difficult to apply with accuracy during surgery, especially in patients with severe degenerative changes (eg, with large osteophytes), or with anatomic variations that may affect the final angulation. For this reason, the technique used by the senior author (KDR) is based on real intraoperative parameters, which may allow surgeons to insert a large lateral mass screw with safety and efficacy. We read with interest the article published by Amhaz-Escalar et al, in which they “build such distorted cube mentally and then imagine the diagonal from the medial lower area of the posterior ridge to the upper lateral of the anterior ridge” to insert screws in cadaveric specimens. Our technique uses a standard entry point (1 mm medial and 1 mm caudal to the center of the lateral mass), with trajectory based on rigid anatomical landmarks (lateral angulation aiming toward the upper and outer corner of the lateral mass and sagittal inclination aiming toward the upper and outer corner of the lateral mass), instead of a mentally based trajectory. We congratulate Amhaz-Escalar et al for the interesting article and agree that it is practically cumbersome to insert lateral mass screws based on numeric values.

Andrei Fernandes Joaquim, MD, PhD University of Campinas (UNICAMP), Campinas, São Paulo, Brazil Marcelo Luis Mudo, MD, MSc São Camilo Hospital, Itu, São Paulo, Brazil Lee A. Tan, MD UCSF Medical Center, San Francisco, CA, USA K. Daniel Riew, MD Columbia University Medical Center, New York, NY, USA