EM~ERGENCY CASE REPORT

Rotatory Subluxation of the Atlas on the Axis

Aldo D. lulo, MD Robert A. Goldstone, MD

Paterson, New Jersey

The clinical f indings of rotatory subluxat ion of the atlas are subtle and x-ray films involv ing the upper cervical segment are difficult to inter- pret. Neverthe less , pat ients with rotatory sub luxat ion must be sep- arated from those with "stiff necks," for they require hospital admis- sion for cervical traction if compl icat ions are to be avoided. A case is reported and m a n a g e m e n t and diagnosis are reviewed.

lulo AD, Goldstone RA: Rotatory subluxation of the atlas on the axis. JACEP ~:523-524, July 1976. subluxation, rotatory, atlas; cervical spine; torticollis; sprain, cervical.

INTRODUCTION

The emergency phys ic ian is often confronted wi th problems t h a t con- found o t h e r s p e c i a l i s t s . One such puzzle is the d iagnosis and x- ray fi lm interpretation of in jur ies to the cer- vical spine, in jur ies which often pro- duce c o n s i d e r a b l e m o r t a l i t y a n d morbidity. In par t i cu la r , the patho- logic a n a t o m y and x - ray f i lm find- ings of r o t a t o r y s u b l u x a t i o n or ro- tatory f ixat ion of C1 on C2 are often ill-defined. Despi te tha t , the emer- gency phys ic ian may be in the diffi- cult c i rcumstance of m a k i n g the ini- tial d iagnosis of th is ent i ty .

CASE REPORT

A 2 0 - y e a r - o l d m a n came to t he emergency d e p a r t m e n t wi th severe ~eck and r i g h t shoulder pa in af te r

From the Orthopedic Department, St. ]0seph's Hospital and Medical Center, I)aterson, New Jersey.

t~ddress for reprints: Aldo D. Iulo, MD, Orthopedic Depar tment , St. Joseph's ~ospital and Medical Center, 703 Main ~treet, Paterson, New Jersey 07503.

being involved in an automobi le ac- cident. He was dr iv ing a mai l t ruck t h a t was s t r u c k f rom the s ide by another vehicle. He was th rown from his seat s t r i k ing the r i gh t door wi th his r i g h t shou lde r . He h a d severe neck pain, was unable to move his head and had immed ia t e onset of tor- t i c o l l i s to t h e left . T h e r e was no weakness , numbness or paresthes~a in the ex t remi t i e s and no other ap- p a r e n t i n ju r i e s . He r e m a i n e d con- scious.

The pa t i en t ' s head was t i l t ed to the r igh t and t u rned s l ight ly to the left ( F i g u r e 1). Mot ion of t he ce rv i ca l spine was genera l ly res t r ic ted bu t he was able to ro ta te approx ima te ly 10 ° to the left wi thou t discomfort. How- ever, any a t t e mp t to ro ta te his head to the r igh t produced severe discom- fort. There was genera l i zed muscle spasm in the neck and tenderness of the s t e rnoc l e idomas to id and t r ape- zius muscles. Pa lpa t ion of the spin- ous process revea led tenderness over t he u p p e r c e r v i c a l v e r t e b r a e . The resu l t s o f neuro logmal e x a m i n a t i o n were un re ma rka b l e .

A t en ta t ive diagnosis of acute cer- vical spra in , rule out ro ta to ry sub- luxa t ion of C1 on C2, was made. The neck was immobi l i zed and the pa- t i en t was sent for x- ray examinat ion , which included anteropos ter ior (AP), l a te ra l and open mouth views of the cervical spine. A shift of the odontoid in re la t ionsh ip to the l a t e ra l mass of C1 on the open mouth view, as well as a na r rowing of the left apophyseal jo in t space, reinforced the diagnosis of ro ta to ry sub luxa t ion of C1 on C2 ( F i g u r e 2). AP t o m o g r a m s t a k e n af ter the pa t i en t was admi t t ed to the hospi ta l for cervical t rac t ion showed t h e l a t e r a l m a s s e s in d i f f e r e n t p lanes . C i n e r a d i o g r a m s showed C1 moving in concordance with C2, in- d i c a t i n g t h a t C l , was r o t a t e d and fixed upon C2. The pa t i en t responded to t he rapy and was d ischarged in a cervical collar. He was to be followed in a pr iva te or thopedis t ' s office.

DISCUSSION

Rotatory sub luxa t ion is felt to be a un i l a t e r a l forward ro ta t ion of the in- ferior facet of C1 on C2 1 The degree of des t ruc t ion or l ax i ty of the t rans- verse l i gamen t is difficult to deter- m i n e . T h e r e a s o n for f i x a t i o n is hypothet ica l . Face t fracture, facet ir- r egu l a r i t y and soft t i ssue interposi- t ion have al l been sugges ted}

R o t a t o r y s u b l u x a t i o n is f a i r l y common in chi ldren bu t may also be seen in adults.~, 2 In the child, there can be a preceding upper resp i ra tory i n f e c t i o n or m i n i m a l t r a u m a , in

J•PJuly 1976 Volume 5 Number 7 Page 523

F i g 1. The head is tilted to the right and slightly rotated to the left, like a robin listening for a worm.

Fig . 2. The dens is more closely approximated to the left lateral mass and there is narrowing o f the apophyseal jo in t space on the left side.

which his head is j e rked or struck. The child presents wi th a tor t icol l is t ha t might not be immed ia t e ly obvi- ous bu t is the key to the diagnosis . In the adult , the t r a u m a incident is a more defini te h i s tor ica l occurrence. The pa t i en t sus ta ins t r a u m a to t h e h e a d or t r u n k t h a t r e s u l t s in an ab rup t ro ta tory motion of the cervi- cal spine. 3

On physical examina t ion the head is typica l ly t i l t ed toward and ro ta ted away from the involved facet. There

is m u s c l e s p a s m a n d t e n d e r n e s s , especial ly on pa lpa t ion of the upper cervical v e r t e b r a pos ter ior ly . A sa- l ien t fea ture is the ab i l i ty of the pa- t i en t to ro ta te his head in the oppo- si te direction. 2 There are r a r e ly any immedia t e neurological sequelae as- sociated wi th ro ta tory sub luxa t ion l , 2 but this does not~negate the necess i ty of a thorough neurological examina- tion.

F i e l d i n g ~ r e p o r t s t h a t , a l t h o u g h t h e s e i n j u r i e s a r e u s u a l l y m i n o r ,

t h e r e h a v e been 11 d e a t h s due "uncontrol led ro ta t ion of the at las ~ the axis . " A n o t h e r compl ica t ioa il the poss ib i l i ty of the lesion becorai~ fixed. F i e ld ing t r ea t ed five cases ~! ro ta tory sub luxa t ion overlooked fr0~ 5 to 24 months , a l though the findiag~ of phys ica l examina t ion were typical In these five cases, the lesions be came fixed and r equ i r ed fusions.

AP and l a t e r a l project ions of thq cervical spine should be ordered bUl t h e c l in ic ian should concentra te 0I the open mouth view. 1 Here the spi~t of C2 m a y be noted on the same sid~ of the chin, wi th the spine of C1% posite the chin. The odontoid is dis placed from the midl ine . The spin0~ processes of the r e m a i n i n g cervica v e r t e b r a e w i l l be w i t h C2 ant l a m i n a g r a m s wil l show one latera mass o f C1 out of focus wi th i ts c0~ t r a l a t e r a l member . The above find i n g s s u g g e s t t h a t C1 is inappr0 p r i a t e l y r o t a t e d a n d f ixed on C2 More s o p h i s t i c a t e d s tud ie s includl c ine rad iograms of the upper cervica segments t h a t wil l show tha t C1 ant C2 move in Unison, ind ica t ing fixa t ion of the a t l as on the axis.

CONCLUSION

In c o n c l u s i o n , t h e emergenc! phys ic ian mus t consider a diagnosi= of ro ta to ry f ixat ion when a child 0 ' adu l t p resen ts wi th an acute trauma tic tort icoll is , even when the injury il minor. In i t i a l j u d g e m e n t may deter mine how soon t r e a t m e n t is begul and ave r t the ca tas t rophy of a la~ diagnosis . A d m i t t i n g the pa t ien t f0 ce rv ica l t r a c t i o n a n d f ind ing late t ha t the re is no ro ta to ry subluxati0~ is harmless , r e su l t ing only in a bric hospi ta l s tay. To diagnose a rotator s u b l u x a t i o n in t he e m e r g e n c y de p a r t m e n t r equ i res an awareness ¢ the cl inical ent i ty , an index of suspi cion, a good his tory and clinical e~ a m i n a t i o n a n d a p p r o p r i a t e x-ra: films.

REFERENCES

1. Fielding WJ: Selective observation o

the cervical spine in the child. Curren Practice in Orthopedic Surgery 5:31-5! 1973.

2. Blount WP: Fractures in Children Baltimore, Wil l iams and Wilkins Cc 1955. 3. Tachdjian MO: Pediatric Orthopedict Philadelphia, W B Saunders Co, 1972.

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