PMID- 23236302
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20121214
LR  - 20211021
IS  - 1663-7976 (Print)
IS  - 1869-4136 (Electronic)
IS  - 1663-7976 (Linking)
VI  - 3
IP  - 1
DP  - 2012 Feb
TI  - Pediatric atlanto-occipital dissociation: radiographic findings and clinical 
      outcome.
PG  - 19-26
LID - 10.1055/s-0031-1298597 [doi]
AB  - STUDY DESIGN:  Retrospective diagnostic feasibility study and clinical review. 
      OBJECTIVES:  To evaluate the feasibility of making an initial atlanto-occipital 
      dissociation (AOD) diagnosis from four radiological measurements of the 
      craniocervical relationship on lateral cervical spine x-rays and to assess the 
      AOD patients' clinical outcomes relative to their magnetic resonance imaging 
      (MRI) findings. METHODS:  The Powers ratio, Wackenheim line, basion-dens distance 
      (BDD), and the C1/2:C2/3 interspinous ratio were measured in 58 pediatric 
      controls and ten MRI-confirmed patients with AOD. The ability to identify the 
      required anatomical landmarks and make the measurements was noted and sensitivity 
      and specificity calculated. The correspondence between the clinical presentation 
      and outcomes for patients with AOD and their MRI features was investigated. 
      RESULTS:  Clear landmarks for measuring interspinous ratio and Wackenheim line 
      were confirmed by all x-rays. The BDD was measureable in 90% and the Powers ratio 
      could be calculated in only possible in 59%. The interspinous ratio and BDD 
      offered high sensitivities and specificity. Although the Wackenheim line was 
      consistantly measured, it conferred a low sensitivity but reasonable specificity. 
      The Powers ratio offered high specificity with low sensitivity. On MRI, all 
      patients with AOD had apical ligament disruption, with a high rate of 
      interspinous ligamentous injury (8/9); prevertebral swelling (7/9); retroclival 
      hematoma (6/9); and tectorial membrane injury (4/9). The only MRI feature 
      associated with poor outcome was that of altered cord signal. Both patients who 
      died had cord signal changes on T1- and T2-weighted images. The third patient 
      with cord signal change was limited to T2 changes with a normal T1. He had a 
      C5-L3 sensory deficit that resolved. The degree of tectorial membrane injury did 
      not appear to influence outcome. CONCLUSIONS:  The BDD and interspinous ratio 
      offer the best measures for initial x-ray diagnosis of AOD. This will alert the 
      surgeon to the need for MRI. These patients often have a reduced level of 
      consciousness, thus making clinical evaluation difficult. The MRI findings, 
      although apparently indicative of severe abnormality, did not actually correspond 
      to outcomes except for the presence of T1 cord signal changes that matched with 
      severe neurological impairment and subsequent death.
FAU - du Plessis, Jean-Pierre
AU  - du Plessis JP
AD  - Division of Orthopaedic Surgery, University of Cape Town, South Africa.
FAU - Dix-Peek, Stewart
AU  - Dix-Peek S
FAU - Hoffman, Eduard Bernard
AU  - Hoffman EB
FAU - Wieselthaler, Nicky
AU  - Wieselthaler N
FAU - Dunn, Robert Neil
AU  - Dunn RN
LA  - eng
PT  - Journal Article
PL  - Germany
TA  - Evid Based Spine Care J
JT  - Evidence-based spine-care journal
JID - 101546672
PMC - PMC3503515
COIS- The author has no conflict of interest for this study. No funding was received 
      for research.
EDAT- 2012/12/14 06:00
MHDA- 2012/12/14 06:01
PMCR- 2012/08/01
CRDT- 2012/12/14 06:00
PHST- 2012/12/14 06:00 [entrez]
PHST- 2012/12/14 06:00 [pubmed]
PHST- 2012/12/14 06:01 [medline]
PHST- 2012/08/01 00:00 [pmc-release]
AID - 03019 [pii]
AID - 10.1055/s-0031-1298597 [doi]
PST - ppublish
SO  - Evid Based Spine Care J. 2012 Feb;3(1):19-26. doi: 10.1055/s-0031-1298597.