Transoral Atlantoaxial Reduction Plate (TARP) Technique for the Treatment of Irreducible Atlantoaxial Dislocation (IAAD) Caused by Old Odontoid Fracture.

Study design: Retrospective case series study.

Objectives: This study aimed to evaluate the clinical efficacy of TARP technique for treating IAAD caused by old odontoid fracture and assess the outcomes of patients who underwent TARP technique over 2 years of follow-up.

Methods: Between January 2005 and September 2017, 56 patients with IAAD caused by old odontoid fractures were treated with TARP technique. Patients' clinical, radiological, and surgical data were retrospectively analyzed. Radiological parameters included the atlantodental interval (ADI) and the space available for the spinal cord (SAC) were measured. Occipitocervical pain levels and neurologic status were evaluated with Visual Analog Scale (VAS) and Japanese Orthopaedic Association (JOA) score respectively. Degree of cervical dysfunction was assessed by Neck Disability Index (NDI). Fusion status was evaluated by images during the follow-ups.

Results: Surgeries for 56 cases were performed successfully with no injury to the spinal cord, nerve, or blood vessels. All patients achieved satisfactory reduction and fixation. Clinical symptomatic relief was obtained in all cases (100%). Patients were followed up for an average of 33.9 ± 9.6 months (ranged 24-60 months). Improvements in the postoperative ADI, SAC, VAS, JOA score and NDI were significant (P < .05). Besides, Bone fusion was observed in all patients. No hardware failure or re-dislocation occurred during the follow-up period.

Conclusions: TARP technique is an effective procedure for the treatment of IAAD caused by old odontoid fracture, which can achieve complete release, satisfactory decompression, reduction and fixation, and reliable bone fusion through a single transoral approach.