Table 4. Select clinical series.
| Authors | Study design | Demographics | Etiology | Surgery | Outcomes and complications |
|---|---|---|---|---|---|
| Wang et al (2007)54 | Retrospective clinical and radiologic case series | n = 57; 35 M, 22 F; mean age: 35 y (range, 13–66 mo); average follow-up 47 mo (range, 24–76) | Reducible atlantoaxial dislocation (AAD): os odontoideum (n = 26) | Transarticular screw fixation with morselized autograft (n = 57) | 2 screw malplacements: 1 penetrated to occipitoatlantal joint, 1 slightly breached vertebral artery groove, no clinical sequelae |
| Reducible AAD: transverse ligament disruption/relaxation (n = 20) | |||||
| Reducible AAD: odontoid fracture nonunion (n = 6) | |||||
| Irreducible AAD: os odontoideum (n = 1) | Transoral anterior AA joint release and reduction for irreducible AAD (n = 5) | No screw fracture, loosening, or backing out | |||
| Irreducible AAD: transverse ligament relaxation (n = 1) | No pseudarthrosis | ||||
| Irreducible AAD: malunion of odontoid fracture (n = 3) | 2 cases of postoperative iatrogenic C2–C3 instability | ||||
| Harms and Melcher (2001)88 | Retrospective clinical and radiologic case series | n = 37; 19 M, 18 F; mean age: 49 y (range, 2–90) | Fractures (n = 20) | Polyaxial C1L-C2PSF (n = 37) | 1 deep wound infection |
| Symptomatic os odontoideum (n = 6) | No cases of implant failure | ||||
| Rheumatoid arthritis (n = 4) | Solid fusion in all patients | ||||
| Rotary subluxation (n = 3) | Transoral odontoidectomy (n = 2) | ||||
| Osteoarthritis C1–C2 (n = 2) | Satisfactory screw placement in all patients | ||||
| Congenital malformation (n = 2) | No dural laceration or vertebral artery injury |
Abbreviations: AA, atlantoaxial; AAD, atlantoaxial dislocation; C1L-C2PSF, C1 lateral mass screw and C2 pedicle screw fixation.