Evaluation of Pars Repair Using Smiley Face Rod Technique in Isthmic Spondylolisthesis

Background: Among adults, isthmic spondylolisthesis af-fects a relatively tiny percentage of people. Even though low back pain is prevalent in these individuals on a level with the general population, both the pars interarticularis defects and forward slide can act as separate pain inducers. Degenerative changes brought on by the deformity or nerve root impingement linked to the pars defect may cause neurologic symptoms. Surgical decompression and stabiliza-tion may be beneficial for patients with neurologic symptoms or intractable pain, though the majority of symptomatic cases can be effectively managed without surgery. Surgery on carefully selected patients had >80% success rates with a low rate of complications. Surgical procedures can include decompression, fusion at the posterolateral level, fu-sion at the anterior lumbosacral interbody level, and fusion at the circumferential level. Aim of Study: The aim of the study is to evaluate direct pars repair using smiley face-shaped rod technique by utilizing bony graft from iliac crest for direct fusion at the site of the pars defect in isthmic spondylolisthesis patients admitted to the Neurosurgery Department at Alexandria Main University Hospital. Patients and Methods: This study is conducted on 30 con-secutive adult patients presenting with isthmic lumbar spon-dylolisthesis. Direct pars repair using smiley face-shaped rod technique with iliac crest bone graft for 30 patients. Preoperatively, all patients included in the study will be subjected to: • Detailed history taking. • Complete physical examination. Clinical assessment preoperatively will include complete neurological examination and estimation of low back pain and sciatica severity. Investigations for assessment of the patients: 1- Plain X-ray of the lumbar spine (anteroposterior, lateral, and dynamic views). 2- Computed tomographic (CT) scan of the lumbar spine. 3- Magnetic resonance imaging (MRI) of the lumbar spine. Results: According to post-operative fusion for pars de-fect, the study showed that at 3 months post operative it ranged from 25.0-35.0 with mean value 31.10±4.19 and median 32.0, while at 6 months post operative it ranged from 40.0-60.0 with mean value 52.17±6.52 and median 50.0, however at 12 months post operative it ranged from 73.0-92.0 with mean val-ue 79.23±4.84 and median 80.0. Between various follow-up intervals, there was a statistically significant variation in the post-operative fusion rates. (p≤0.05). Conclusion: The Smiley face rodmethod for pars repair in patients with isthmic spondylolisthesis is an effective tech-nique to manage pars defect if the disc is healthy, if there is no or minimal slippage of the vertebrae (<2mm), and efficient for preservation of the motion segment especially in adolescent athletes.