Abstract
We describe the results of a prospective case series to evaluate a technique of direct pars repair stabilised with a construct that consists of a pair of pedicle screws connected with a u-shaped modular link that passes beneath the spinous process. Tightening the link to the screws compresses the bone grafted pars defect providing rigid intrasegmental fixation. 20 patients aged between 9 and 21 years with a pars defect at L5 confirmed on computed tomography (CT) were included. The average age of the patients was 13.9 years. The eligible patient had Grade I or less spondylolisthesis and no evidence of intervertebral degeneration on MRI. The average duration of follow-up was 4 years. Clinical assessments for all patients was via the Oswestry disability index (ODI) and visual analogue scores (VAS). At the latest follow-up, 18 of the 20 patients had excellent clinical outcomes with a significant (p<0.001) improvement in their ODI and VAS scores with a mean post-operative ODI score of 8%. Fusion of the pars defect as assessed by CT showed fusion rates of 80%. There were no hardware complications. The strength of the construct obviates the need for post-operative immobilisation.
