NON-UNION OF ODONTOID FRACTURES

: A CASE REPORT

Dr. TARUN KUMAR BADAMPROF . A.DEVADOSS ( Chief of Orthopaedics )

PROF. MUTHUKUMAR ( Neurosurgeon )

NON-UNION OF ODONTOID FRACTURES

ANATOMY OF CRANIO-VERTEBRAL JUNCTION

OSSEOUS AND LIGAMENTOUS STRUCTURES IN CRANIO-VERTEBRAL JUNCTION

ANTERIOR VIEW

LATERAL VIEW

POSTERIOR VIEW

ATLAS

AXIS

TIP OF DENS

WAIST OF DENS

BODY OF DENS

CRUCIFORM AND TRANSVERSE ATLANTAL

LIGAMENT

ALAR AND APICAL LIGAMENTS

BLOOD SUPPLY

BLOOD SUPPLY OF AXIS VERTEBRAE

DIGITAL SUBSTRACTION ANGIOGRAM

Text

CLASSIFICATION OF ODONTOID FRACTURES

CLASSIFICATION OF ODONTOID FRACTURES

ANDERSON AND D’ALONSO CLASSIFICATION

TYPE I : Oblique avulsion # of the tip of the odontoid

TYPE II : # through the waist of odontoid

CT SCAN : Saggital view of Type II odontoid fracture

TYPE III : # of the base of the odontoid extending into the superior articular facet

CLINICAL FEATURES

Patient generally presents with h/o trauma

Neck pain after injury

Neurological deficits, if spinal canal is compromised

RAIOLOGICAL INVESTIGATIONS

X - RAY :

A. Spino laminar line

B. Posterior vertebral line

C. Anterior vertebral line

D. Facetal joints, as stacked parallelograms

E. > 7mm at C2-C3

F. > 21mm at C5-C7

CT SCAN

Displacement > 5mm

Angulation > 10 degrees

INDICATION OF SURGICAL INTERVENTION

CT SCAN

ADI : Atlanto Dens Interval

< 3mm

PADI : Posterior Atlanto Dens Interval

>13 mm

MANAGEMENT OF ODONTOID FRACTURES

CONSERVATIVE MANAGEMENT

RUFF’S COLLAR

SOMI HALO VEST

SURGICAL MANAGEMENT

1) Posterior Trans articular Screw

construct

SURGICAL MANAGEMENT

2) Posterior C1 Lateral mass screw and C2 Pedicle screw Construct

SURGICAL MANAGEMENT

3) Anterior Odontoid Screw fixation- ideal for Type II odontoid fractures- # line should pass from Antero-superior to Postero-inferior

surface

COMPLICATIONS IN ODONTOID FRACTURES

NON UNION 40-50% in Type II #

CASE REPORT

24yr old male

H/o fall from 20 ft ht

C/o Pain in the neck

Tenderness over C1,C2

NO NEUROLOGICAL DEFICITS

No h/o Bowel and Bladder dysfunction

19/04/2014 X RAYS

19/04/2014 CT SCAN

1-2 mm Displacement and No Angulation

19/04/2014CT SCAN AND MRI SCAN

DIAGNOSIS : Type II Odontoid fracture with Minimal displacement and Angulation, with No Neurological deficits

Patient treated conservatively with Ruff’s collarMinimal displacementNo angulationNo neurological deficits

Patient reviewed every month

11/07/2014 X RAY• Minimal Displacement

• Pre-vertebral soft tissue shadow is less

16/08/20144 months post injury, patient started developing Neurological deficits in the form of Numbness of

upper limbs

Advised Surgery (Posterior Stabilisation of C1,C2), Patient was not willing for surgery

15/09/20141 month later patient presented with deterioration of Neurological function with Increased numbness of Upper limbs

19/09/2014Planned for Surgical intervention

Posterior C1-C2 fusion: Posterior C1 lateral mass screw and C2 pedicle screw construct was used

IIiac crest Bone grafting: Biological fixation

20/09/2014 POD 1

CT SCAN : POST-OP

CORONAL VIEW

POST-OPERATIVE PERIOD

Patient condition was stable Numbness decreased and Neurologically improved

Discharged on 12th day

29/10/2014

Patient was stable and Neurologically improved

DILEMMA

During the course of treating this patient, we had a doubt why Non-union has occurred in this patient

Is it mainly due to WATERSHED AREA or something else ?

Review of Literature has revealed some interesting facts …..

ANGIOGRAPHIC AND POSTMORTEM SPECIMEN EVALUATION OF ODONTOID FRACTURES - JBJS Br , 2000

183 patients of Odontoid fractures have been treated conservatively ( 109 Type II and 74 Type III )

Union achieved 100% in Type III # , 54% in Type II #

For evaluation of cause of Non-union, Selective Vertebral angiography and Digital Substraction Angiogram was done in 18 patients - 10 with acute # and 8 with established Non-union

It showed that blood supply to Odontoid was not affected

Histologically, No evidence of Avascular Necrosis of Odontoid process

Posterior ascending artery which is dominant branch from Vertebral artery is always intact

Anterior ascending branch of Vertebral artery is always cut, which doesn't affect the blood supply to Odontoid

POST-MORTEM SPECIMEN EVALUATION

Findings :

A. Low Bone density

B. Less bony trabecular

C. Cortical bone

D. Less surface area

These might be responsible for the Non-union of the waist of Odontoid fractures

in the waist of odontoid

Finally, Cause of Non-union is Multi-factorial and blood supply to odontoid process is not

compromised in Type II odontoid fractures

1. Transverse Atlantal ligament interposition2. Less Bony trabeculae and Bone density3. Late presentation to the Hospital4. Displacement of > 5mm and Angulation of >

10 degrees 5. Inadequate Immobilsation

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