Transpedicular Hook Screw Fixation in the Treatment of Lumbar Spondylolysis in Young Patients

Abstract

Objectives: In spondylolysis, there is a defect in the pars interarticularis. Most patients with spondylolysis, and even some with spondylolisthesis are asymptomatic, and they grow up not even aware of their condition. However, back pain is the most common symptom. Most patients with lumbar spondylolysis and low-grade spondylolisthesis can be treated conservatively. Surgical treatment is indicated when any type of spondylolisthesis is accompanied by a neurological deficit. Materials and Methods: We reviewed records obtained in patients treated surgically between 2000 and 2004 at Cathay Medical Center. We found a total of eight patients with a diagnosis of lumbar spondylolysis (pars fracture). In these patients-six men and two women, with ages ranging from 17 to 37 years. The diagnosis was made according to plain radiography, CT scan and MRI imaging. For patients with spinal instability, instrumentation included the trans-pedicular screws to secure the hook. Sufficient amounts of onlay autogenous cancellous bone graft across the spondylolytic defect were performed in all our patients. The final outcome was assessed by the following criteria:(1) whether instruments remained intact;(2)whether the postoperative fracture reduction was maintained;(3)whether the functional outcome was satisfactory; and(4)preoperative and postoperative plain radiographs. Results: We found a total of eight patients with a diagnosis of lumbar spondylolysis (pars fracture). Instrumentation included the trans-pedicular screws to secure the hook. Sufficient amounts of onlay autogenous cancellous bone graft across the spondylolytic defect were performed in all our patients. Follow-up plain radiography was done every 3 months after the operation. All our patients experienced significant pain relief from low back pain and radiculopathy. No screw pullout or loosening of the instrument was observed. No pseudoarthrosis was noted and all our patients had a bilateral union. In this article, we examine the effectiveness and advantages of transpedicular hook screws in the treatment of lumbar spondylolysis. Conclusions: Direct repair of spondylolysis with transpedicular hook screws can be recommended for patients with young age, a slight slip, an instability, or failure of conservative treatment.