CORA ABSTRACT #VI - 2

A NEW DEVICE FOR SAFE PLACEMENT OF PEDICLE SCREWS IN THE THORACIC SPINE

J.M. Mac-Thiong

H. Labelle

M. Rooze

V. Feipel

C-E Aubin

Insertion of pedicle screws in the thoracic spine is technically difficult and may lead to major complications. This study evaluated a transpedicular drill guide (TDG) designed to assist in the safe placement of thoracic pedicle screws. Pilot holes were made manually using the TDG in the thoracic spine (T1 to T11) of three human cadavers before inserting 4.5 mm diameter screws. CT scans followed by visual inspection of the spines were performed to evaluate the position of the screws. Five of 66 (7.6%) screws violated the pedicle wall: two (3.0%) medially and three (4.5%) laterally. The medial and lateral perforations were within 1 mm and 2 mm of the pedicle wall, respectively. The medial perforations were not at risk of causing neurological complications. No screw penetrated the superior or inferior pedicle wall. The TDG was easy to use and decreased the incidence of misplaced thoracic pedicle screws. The TDG could be used as a complement to fluoroscopy in certain applications, especially for training surgeons. A clinical trial with adolescent idiopathic scoliosis patients is currently under progress using a newly improved design of the TDG.