Occipital Condyle Fractures: Epidemiology, Classification, and Treatment Sabih T Effendi, Kevin C Morrill, Howard Morgan, David P Chason, Richard A Suss, Christopher J Madden Department of Neurosurgery University of Texas Southwestern Medical Center Dallas, TX

Disclosure Statement Nothing to disclose

History Sir Charles Bell (1817) Rare entity Increasingly diagnosed – Imaging enhancements – Routine imaging Middlesex Hospital Journal 4: , 1817

REVIEW OF LITERATURE

Classification Systems Anderson and Montesano (1988) – Mechanism of injury → fracture morphology – Type I = comminuted –Type II = basilar skull fx – Type III = avulsed Spine 13: , 1988

Classification Systems Tuli et al (1997) – Type 1 = non-displaced – Type 2 = displaced (2A – stable, 2B – unstable) – Instability CT/Xray – subluxation OR MRI – avulsed transverse ligament Newer systems – A-M system – Stability assessment Hanson et al (2001) – bilateral O-C1-C2 joint complex injury Malham et al (2009) – displaced fracture or malalignment of joint Neurosurgery 41: , 1997 American Roent Ray Soc 178: , 2002 Emergency Radiology Online, 2009

Treatment Experience or non-radiographic outcome: – wide range of treatments suggested Radiographic outcome data: – Capuano et al (2004) 10 pts, CT for fusion All isolated OCF healed well with cervical collar – Malham et al (2009) 24 pts, CT for fusion and alignment & pain and disability scales Isolated type I and II heal well with C collar Isolated type III may benefit from halo vs collar Acta Neurochirurgica 146: , 2004 Emergency Radiology Online, 2009

Design Retrospective Review Parkland Memorial Hospital (Dallas, TX) 4 year period Information obtained – Clinical data from medical charts – Initial C-spine CT – f/u flexion extension films

Methods - Classification Type I vs Type III Modified Anderson-Montesano system – Type I, II, III – Type I or III– Type I and III (inability to differentiate)(evidence of both)

Methods - Instability Radiographic Instability Risk Factors Criteria 1. Fragments involve ≥ 25% of condylar articulating surface 2. Fragment displacement ≥ 4 mm 3. Atlanto-occipital dislocation 4. Subluxation of 0-C1 or C C1 or C1-2 joint widening 6. Complete transverse fracture through congenitally fused O-C1 Methods - Outcome Neurological Exam Lateral Flexion-Extension radiographs

EPIDEMIOLOGY 89 OCF in 79 patients – 13% bilateral Gender: 63% M, 37% F Age: 14-64, mean 30, SD 11 Mechanism of Injury: – High energy trauma Associated Fractures: – 47% with spinal fractures MechanismNumber MVC49 (62%) MCC19 (24%) Fall5 (6%) MPC3 (4%) Assault1 (1%) ATV1 (1%) Airplane1 (1%) FractureNumber At least 171 (90%) ≥ 245 (57%) Other cranial15 (19%) Cervical spine25 (32%) Thoracic spine9 (11%) Lumbar spine6 (8%) Facial26 (33%) Appencidular41 (52%) Rib10 (13%)

CLASSIFICATION TypeNumber I11 (12%) II15 (17%) III40 (45%) I and III4 (5%) I or III19 (21%) INSTABILITY Type I and II – All radiographically stable Type III, IandIII, IorIII – 27% with instability risk – 73% radiographically stable

TREATMENT 7 patients died Remaining 72 patients: – Hard cervical collar, CTO, Halo-vest – 4 to 12 weeks None required surgery TREATMENT & OUTCOME 50 (69%) at initial follow-up – No new neurological deficits 21 (29%) with flexion-extension films

TREATMENT & OUTCOME Type I and II Number Radiographic stability TreatmentNumber FollowUp Flex-Exten stable/obtained 24 (30%)All Stable Cervical collar203/3 Halo-vest Death before tx3-

TREATMENT & OUTCOME Type III, IorIII, IandIII Number Radiographic stability NumberTreatmentNumber FollowUp Flex-Exten stable/obtained 55 (70%) Stable40 (73%) Cervical collar348/8 CTO21/1 Halo-vest1+1+ 0/0 Death before tx3- Unstable15 (27%) Cervical collar10/1 Halo-vest138/8 Death before tx1-

CONCLUSIONS High energy trauma, associated fractures Modified A-M Classification System Majority are type III Stability – Type I and II appear stable – Type III concerning for instability Treatment – None required surgery – Type I and II Hard cervical collar – Type III Stable – hard cervical collar Unstable - halo

LIMITATIONS Limited number with complete outcome data Others FUTURE INVESTIGATION Assessing stability in type III fracture Do all type I and II need collar immobilization? Can some “unstable” type III be treated with collars?

Thank You Dr. Christopher Madden Dept of Neurosurgery at UT Southwestern