Many operations have been recommended to treat Pars Interarticularis fractures that have separated and are persistently symptomatic, but little other than conservative treatment has been recommended for symptomatic incomplete fractures. 10 consecutive patients aged 15–28 [mean 21.7 years] were treated operatively between 2010–2014. All but one were either professional athletes [3 cricketers, 2 athletics, 1 soccer] or academy cricketers [3 patients]. 8 patients had unilateral fractures, and two had bilateral fractures at the same level. The duration of pre-operative pain and disability with exercise ranged from 4–24 months [mean 15.4 months]. The operation consists of a percutaneous compression screw inserted through a 1.5cm midline skin incision under fluoroscopic guidance: 6 cases were also checked with the O-arm intra-operatively. Post-operation the patients were mobilised with a simple corset and discharged the following day with a customised rehabilitation program. All 12 fractures in 10 patients healed as demonstrated on post-operative CT scans at between 3–6 months. One patient had the screw revised at 24 hours for an asymptomatic breach, and one patient developed a halo around the fracture site without screw loosening, and had a successful revision operation to remove the screw and graft the pars from the screw channel. All patients achieved a full return to asymptomatic activity, within a timescale of 4–12 months post-surgery, depending on the sport. Athletes that have persistent symptoms from incomplete pars interarticularis fractures should consider percutaneous fixation rather than undergoing prolonged or repeated periods of rest.
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.
