Single door laminoplasty plus posterior fusion for posterior atlantoaxial dislocation with congenital malformation:A case report and review of literature

BACKGROUND Posterior atlantoaxial dislocation(PAD)is a rare type of upper cervical spine disease.We sought to describe a unreported case of old PAD with os odontoideum(OO)and atlas hypoplasia(AH)and our unique treatment approach consisting of C1 single door laminoplasty with C1-3 posterior fixation and fusion.CASE SUMMARY A 70-year-old male patient who suffered from progressive aggravating numbness and limb weakness for 4 years without trauma,was diagnosed with old PAD with OO and AH.The patient underwent closed reduction and C1 single door laminoplasty with C1-3 posterior fixation and fusion instead of C1 laminectomy with occipitocervical fusion.During the 3-year follow-up,he was able to walk by himself instead of using a wheelchair and with a±25°range of head rotation as well as a±10°range of flexion-extension.Three-year follow-up images showed satisfactory reduction and fusion.CONCLUSION C1 single door laminoplasty with cervical fusion in PAD combined with spinal cord compression could be a suitable and effective surgical option.Compared with laminectomy and occipitocervical fusion,it retains more cervical range of motion,has a smaller incision and provides an adequate bone grafting space for atlantoaxial fusion.

Early reoccurrence of traumatic posterior atlantoaxial dislocation without fracture:A case report

BACKGROUND In general,atlantoaxial dislocation is rare due to the stability of the C1-C2 complex.Traumatic atlantoaxial dislocations are usually anterior and accompanied by odontoid fractures.Posterior atlantoaxial dislocations are rare,and complete posterior dislocation without associated fracture is even more rare.A case of early recurrence of posterior atlantoaxial dislocation without fracture being in therapy of first closed reduction and then open reduction has not been previously reported.CASE SUMMARY A 45-year-old female presented with traumatic posterior atlantoaxial dislocation(TPAD)of C1-C2 without associated fractures,and Frankel Grade B spinal cord function.She was successfully managed by immediate closed reduction under skull traction.Unexpectedly,17 d later,re-dislocation was discovered.On day 28,closed reduction was performed as before but failed.Then,open reduction and posterior internal fixation with autologous iliac bone grafts was performed.By 6 mo after surgery,atlantoaxial joint fusion was achieved,and neurological function had recovered to Frankel Grade E.At 12 mo follow-up,she had lost only 15°of cervical rotation,and atlantoaxial complex instability in joint flexing and extending were no longer observed under fluoroscopy.CONCLUSION Early assessment of transverse ligament is critical for TPAD without fracture avoiding re-dislocation after closed reduction.

One stage anterior release and posterior fusion for the treatment of irreducible atlantoaxial dislocation secondary to os odontoideum

Objective To evaluate clinical effect of the ventral release through high anterior cervical retropharyngeal approach and one stage posterior fusion for the treatment ofirreducible atlantoaxial dislocation (IAAD) secondary