Restore irreducible atlantoaxial dislocation by anterior joint release through wedge-end-mini-channel and posterior fixation / 中华骨科杂志

ABSTRACT

Objective:To investigate the feasibility and safety of a novel surgery, to restore irreducible atlantoaxial dislocation (IAAD) by atlantoaxial joint release through wedge-end-mini-channel (via conventional Smith-Robinson anterolateral approach) combined with posterior fixation.Methods:Five patients with IAAD from May 2013 to December 2021 were retrospectively analyzed, including 3 males and 2 females, aged 44.6±9.0 years (range, 38-61). All the patients received atlantoaxial joint release through wedge-end-mini-channel (via conventional Smith-Robinson anterolateral approach) combined with posterior fixation. The Japanese Orthopedic Association (JOA) score and improvement rate, American Spinal Injury Association (ASIA) grade, atlantodental interval (ADI) and reduction rate, space available for the cord (SAC) and fusion of bone graft were measured and recorded.Results:The follow-up time was 80.0±23.1 months (range, 34-96 months). The surgery time of anterior joint release was 105±23 min (range, 75-135 min), and the total surgery time was 234±42 min (range, 212-276 min). The blood loss of anterior joint release was 80±16 ml (range, 60-100 ml), and the total blood loss was 123±34 ml (range, 85-150 ml). JOA scores were 6.6±0.9 before surgery, 11.2±0.4 at post-operative 1 month, and 14.8±0.80 at the last follow-up ( F=97.28, P<0.001), and the improvement rate of the last follow-up JOA score was 79.1%±7.64%. The ASIA grade were three cases of 'C’ level and two cases of 'D’ level before surgery, and two cases of 'D’ level and three cases of 'E’ level at the last follow-up. The ADI before surgery, at post-operative 6 months and the last follow-up were 9.56±1.07 mm, 1.46±0.39 mm and 1.48±0.29 mm, respectively ( F=206.54, P<0.001). The reduction rate of last follow-up ADI was 84.6%±1.4%. The SAC before surgery, at post-operative 6 months and last follow-up were 10.3±1.83 mm, 20.12±1.19 mm and 20.06±1.25 mm, respectively ( F=44.47, P<0.001). Grafted bone fuse was seen in 3 cases at post-operative 6 months, and 5 cases at post-operative 12 months. The only complication was unexpected titanium rod fracture in 1 case at post-operative 14 months. Conclusion:For IAAD, the novel surgery of atlantoaxial joint release through wedge-end-mini-channel (via conventional Smith-Robinson anterolateral approach) combined with posterior fixation could achieve well joint restoration and neural function improvement, which was a safe and effective procedure.