Anterior single odontoid screw placement for type II odontoid fractures: our modified surgical technique and initial results in a cohort study of 15 patients

Abstract

Objective: Anterior odontoid screw fixation for type II odontoid fracture is the ideal management option. However in the context of unavailability of an O-arm or neuro-navigation and poor images from the available C-arm may be an obstacle to ideal trajectory and placement of the odontoid screw. We herein detail our surgical technique so as to ensure a correct trajectory and subsequent good fusion in Type II odontoid fractures. This may be advantageous in clinical set ups lacking state of the art facilities. Methods and Results: In this cohort study we included 15 consecutive patients who underwent anterior odontoid screw placement. We routinely dissect the longus colli to completely visualize the entire width of C3 body. We then perform a median C2-C3 disectomy followed by creating a gutter in the superior end of C3 body. We then guide the Kirchsner (K) wire purchasing adequate anterior cortex of C2. Rest of the procedure follows the similar steps as described for odontoid screw placement. We achieved 100% correct trajectory and screw placement in our study. There were no instances of screw break out, pull out or nonunion. There was one patient mortality following myocardial infarction in our study. Conclusion: Preoperative imaging details, proper patient positioning, meticulous dissection, thorough anatomical knowledge and few added surgical nuances are the cornerstones in ideal odontoid screw placement. This may be pivotal in managing patients in developing nations having rudimentary neurosurgical set up.

Anterior Single Odontoid Screw Fixation for Type II Odontoid Fractures: In A Cohort Study of 11 Patients and literature review.

“…We created a small gutter on the superior aspect of C3 body like as Sunil Munakomi et al technique, by this method we ensure accurate placement of the odontoid screw behind the anterior cortex of C2 body without deviation from midline. The groove also provides the proper shelter for the screw head avoiding damage to the eosephagus (Munakomi et al, 2016).…”

Anterior Screw Fixation in Type II Odontoid Fractures: Keys for Better Outcome in Early Experience in Developing Countries

“…where 60% of their cases had RTA [22]. and 80% of patients included in Wilson study presented after RTA [23].…”

“…One titanium lag screw was inserted in all cases and this was wise enough in starting up experience .in addition, bone quality was fine as most patients where below 50 years with no history of bone quality affecting diseases. Sunil et al [22] also inserted one screw in all cases, while Dailey et al found that putting 2 screws enhance better fusion but their cases were older than 70 years [24]. And this may explain their need to assure fixation due to possible weak bone quality.…”

Determination and optimization of ideal patient candidacy for anterior odontoid screw fixation

“…[ 8 , 13 ] In contrast, posterior internal atlantoaxial fixation and fusion are indicated for Type IIC fractures that extend anteroinferior to posterosuperior, comminuted fractures, concomitant disruption of the transverse ligament, fractures that are nonreducible or do not maintain adequate alignment, and as a salvage procedure for inadequate healing following conservative treatment or AOSF failure. [ 5 , 8 , 10 , 13 , 20 - 22 , 25 , 28 , 29 , 33 , 36 , 40 ] Displacement of the dens of ≥6 mm and angulation of ≥10° has been associated with a higher rate of nonunion after conservative treatment, as well as AOSF surgical failure, and, thus, is also indications for posterior surgical treatment. [ 12 , 20 , 22 , 24 , 25 , 28 , 44 ] Additional risk factors for AOSF surgical failure include fracture age postinjury of 6 months or greater, as the chance of success for stabilization and osteosynthesis decreases, as well as a fracture gap of >2 mm.…”

“…In patients with significantly reduced bone mineral density, strength, and healing potential, as seen in patients with severe osteoporosis, attaining adequate fixation and fusion are challenging and considered a contraindication given the high possibility for nonunion. [ 1 , 8 , 23 , 29 , 40 ] Body habitus must also be heavily considered, as obesity and structural deformities can impose limitations that may interfere with surgical execution and outcome. A fixed cervical spine with inability to impose neck extension or moderate-to-severe thoracic kyphosis, a short neck, or a barrel-shaped chest restricts proper patient positioning and access to the anterior neck, contraindicating AOSF as a surgical approach.…”