Free-Hand Pedicle Screw Insertion of Thoracic Spine Using Fennell Technique: Initial Results and Review of Literature

Aim of the Study This article aims to study the safety and feasibility of Fennell technique of free-hand pedicle screw insertion in thoracic spine. Methods Consecutive 10 patients in whom 40 thoracic pedicle screw were inserted using Fennell’s technique were included in the study. Postoperative computed tomography scan was done in all the patients. Breach in individual pedicle was analyzed using Gertzbein classification. Results A total of 40 screws were placed in the thoracic spine in 10 patients by free-hand technique described by Fennell et al. Out of 40 pedicle screws, 26 were placed at the D10 to D12 level, 8 screws were placed at the D7 to D9 level, and 6 screws were placed at the D1 to D6 level. There was one pedicle with grade 1 lateral breach and one pedicle with grade 1 medial breach as per Gertzbein classification. All other screws were contained within the pedicle (Gertzbein grade 0). None of the patients had any added deficits or wound complications in the postoperative period. Conclusion Thoracic pedicle screw insertion is challenging in nature because of the anatomic variability and proximity of critical structures to the pedicles. Our experience suggests that Fennell technique is a reliable technique, which can be used to place thoracic pedicles consistently, with acceptable rates of pedicle breach. A study involving larger number of patients might prove to establish this technique as an easily reproducible and safe technique for free-hand pedicle screw insertion in thoracic spine.