Comparison of the accuracy of the cannulated pedicle screw and the classical pedicle screw in the treatment of Scheuermann’s kyphosis: A retrospective study

OBJECTIVES: This study aims to investigate if use of cannulated pedicle screw (CPS) in the dysplastic pedicles in Scheuermann’s kyphosis (SK) increases the accuracy rate of the screw and reduces screw-related complications. PATIENTS AND METHODS: This retrospective study included 21 patients (11 males, 10 females; mean age 19.1 years; range, 13 to 22 years) (550 screws) who received correction with pedicle screws due to SK deformity between May 2015 and January 2019. Between 2017 and 2018, classical pedicle screws were used in addition to CPSs in the upper thoracic region (T2, T3, T4) and thin pedicles (group 1). However, during the years 2015 to 2016, only classical pedicle screws were used for the patients who underwent posterior instrumentation for SK (group 2). Computed tomography scanning was used to investigate the accuracy of the screws. RESULTS: There were 12 patients (316 screws) in group 1 and nine patients (234 screws) in group 2. Seventy-four (13.4%) of all screws were inserted incorrectly. Incorrect screw rate in group 1 was significantly lower than group 2; 21 (6.6%) and 53 (22.6%), respectively (p<0.001). There were no complications related to the use of CPSs after a mean follow-up of two-and-a-half years. CONCLUSION: The use of CPS in the surgical treatment of SK does not increase the complication rate; instead it increases the accuracy of the screw. For this reason, we believe that CPS may be an effective and reliable option in the treatment of SK.