CASE REPORT

REPAIR OF FRACTURES OF THE AXIS

C. L. GENDREAU AND A. J. CAWLEY*

IntroductionThe axis and the atlanto-axial joint are the

most common sites of injury of the cervicalspine in small animals (8, 9, 10, 11, 12). Suchinjuries include fractures, various degrees ofluxations and fracture-dislocations. Severe dam-age to the brain stem may result. This mayoccur several days after the initial trauma orconcomitantly with it. Adequate measuresshould be taken in order to prevent deteriora-tion of the neurologic status or to reverse theexisting damage to the spinal cord. Such meas-ures should relieve compression of the brainstem or prevent the secondary exertion of pres-sure. This is best achieved by restoring thenormal anatomy of the spine and maintainingthe relationship of its components. One methodwhich proved adequate in two dogs with frac-tured axes is presented.

Literature ReviewThe veterinary literature contains few reports

of the repair of cervical fractures and disloca-tions (8, 9, 10, 11, 12). Methods which havebeen advocated for the repair of such fracturesinclude plating of the fractured spinous pro-cess in conjunction with hemilaminectomy (10,12), cord decompression and plaster casting(11, 12) and wiring of the spinous process tothe dorsal arch of the atlas concomitantly withcord decompression by hemilaminectomy (8),9).The most commonly used method of immo-

bilization of fractures of the cervical spine inhumans is skeletal traction by skull calipers inaddition to plaster casting (2, 3, 5, 7, 9, 15,16). When non-operative procedures fail, thefractured section of the spine is usually fused.Methods of posterior fusion include the use ofsmall metal plates (15), wire loops (6, 7, 15,16), bone inserts (1, 4, 6, 7, 14, 16) andfacetectomy ( 14). Fusion of the vertebralbodies is much less practiced (13). In certaincases, a decompression laminectomy is per-formed in conjunction with a method of stabi-lization (14, 15).

'Department of Clinical Studies, Ontario Veteri-nary College, Guelph, Canada.

Material and MethodsCase #1: A six-month-old, female Beagle

was referred to the clinic one week after hav-.ing been involved in a car accident. The ownerreported no neurological signs for five daysafter the accident. At that time the dog becamelame on the left foreleg. On the sixth day thedog was seen by the referring veterinarian. Atexamination he noticed knuckling of the leftforeleg, hyperextension of the ipsilateral hindleg, marked disinclination to walk and severepain about the neck. The next day the dog wasadmitted to the clinic. A radiographic surveydisclosed a fracture through the anterior por-tion of the axis with dorsal displacement of theposterior fragment (Figure 1).

FIGURE 1. Case No. 1. Lateral radiograph of theanterior cervical spine showing the fractured axisand the displaced caudal fragment.

Case #2: A four-month-old, male GermanShepherd dog was admitted shortly after a fallof approximately 12 feet. The animal showedno impairment of motor function but wascarrying its neck very carefully and evincedsevere pain on moving its head. A radiographicexamination disclosed a fracture of the axisimmediately caudal to the odontoid process.The major portion of the vertebra was dis-placed dorsally by approximately one cm(Figure 2).

Surgical Procedure: Both dogs received thesame surgical care. Anaesthesia was induced

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FIGURE 2. Case No. 2. Lateral view of the neck.Fracture of the axis with marked displacement.

with thiamylall and maintained by halothane2delivered through an endotracheal tube. Prepa-ration for aseptic surgery was carried out. Thepatient was then positioned in dorsal recum-bency and sand bags were placed under theneck for support and immobilization.A ventral midline incision was made, from

the cranial border of the pharynx to a pointjust caudal to the manubrium of the sternum.The sternohyoideus muscles were separatedand the trachea, the esophagus and the musclesof the left side of the neck were retracted tothe left. The right jugular and carotid wereretracted to the right side along with the ipsi-lateral muscles. The longus colli muscles werethen separated and elevated from the ventralsurface of the atlas and axis. This exposure isthe same as that used in the fenestration ofcervical intervertebral discs.The fractures were both reduced by prying

the fragments apart with periosteal elevatorsand manipulating with bone-holding forcepswhile gentle traction was applied to the head.Apposition was maintained while small plateswere applied. Human finger plates were shapedto fit the ventral aspect of the axis. Two plateswere applied, one on each side of the medialridge of the vertebral body. They were held inplace with a hemostat while the first holes weredrilled. The screws were then inserted. Thewound was closed with #2-0 chromic catgutinserted in the superficial cervical fascia and#1 silk in the skin.

Post-surgical Care: A plastic3 splint was

ISurital: Parke, Davis and Company, Ltd.,Brockville, Ont.

2Halothane: Hoechst Pharmaceuticals, Montreal,Que.

3San-Splint: Smith and Nephew Ltd., Lachine,Que.

FIGURE 3. Case No. 1. Photograph of the Beagledog taken two days after surgery showing theplastic splint in place. Knuckling of the left fore-limb is evident.

fastened around the neck of the Beagle dogfor the first 10 days after surgery so as to mini-mize stresses on the plated axis (Figure 3). Noexternal support was applied to the other dog.Both patients were given tetracycline hydro-chloride4 orally at a therapeutic dose level forfour days and the equivalent proteolytic activ-ity of 20 mg of crystalline trypsin5 three timesdaily for six days. Codeine phosphate6 wasadministered to the Beagle dog at a dose of 15mg three times daily for five days. In bothinstances, the skin sutures were removed bythe ninth day.

ResultsThe bone plates were well positioned and

the fragments were in good anatomical rela-tionship (Figures 4 and 5). The diameters ofthe neural canals were satisfactorily restored.The condition of the beagle did not show

any improvement before the third post-opera-tive day. On that day she was able to takeseveral steps without knuckling. Seven daysafter surgery her left hind leg still showedsome motor dysfunction and her left forelegstill knuckled occasionally. By the fifteenthpostoperative day, the patient could walk nor-mally and was discharged.Eleven months later the dog was reported to

have shown no neurological signs since her dis-charge and was clinically normal. At that timeshe showed no abnormality of gait and wasleading a normal life including rabbit hunting.

4Achromycin: Cyanamid of Canada Limited,Montreal, Que.

50renzyme: The Wm. S. Merrell Co., Weston,Ontario.

6Codepirin: Ingram and Bell Ltd., Toronto,Ontario.

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FIGURE 4a. Case No. 1. Lateral projection of theplated axis, at completion of the operation.

FIGURE 5b. Case No. 2. Ventro-dorsal radio-graph of the axis, shortly after plating.

FIGURE 4b. Case No. 1. Ventro-dorsal projectionof the plated axis, at completion of the operation.

FIGURE 5a. Case No. 2. Lateral radiograph ofthe axis shortly after plating.

FIGURE 6. Case No. 1. Radiograph taken elevenmonths post-operatively. The dog was clinicallynormal.

FIGuRE 7. Case No. 2. Radiographic appearancefive months after surgery. The amount of callusis minimal. The atlanto-axial joint is functionaland painless.

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Manipulation of the neck did not produce pain.Radiographs showed bony union of the fractureline with excellent position of the fragments(Figure 6). The caudal screw in one of theplates had extruded from its bed in the C 2-3intervertebral space.

Reduction and plating of the fracture in theGerman Shepherd dog was followed by a dra-matic relief of pain. On the first day after sur-gery he was bright, ate well and walked withno evidence of neurological dysfunction orpain. Six days after surgery the dog wasnoticed shaking his head because of otitis ex-terna. Even this did not elicit pain. A radio-graph taken three days later indicated that theposition of the fragments was not altered fromthe time of surgery. The dog was released tendays after surgery.

Five months later the dog was still clinicallynormal and a radiograph (Figure 7) indicatedthat the position of the fragments had beenmaintained and that healing was optimum. Thefracture line was no longer visible and a mini-mal amount of callus was evident.

Discussion

Injuries of the cervical spine pose a definiteneurologic threat. The possibility of neurologicdeterioration, even after the initial trauma,exists and should not be forgotten. Patientssuspected of such injuries should be examinedpromptly and handled with the greatest ofcare.The importance of supporting the head at all

times, especially when the patient is underanaesthesia, must not be overlooked. Until adefinite diagnosis has been reached, the headshould be kept in a neutral position. When itis established that dorsal displacement of thecaudal fragment is present, the neck should beextended, especially if the site of the injuryis in the cranial cervical spine. Such a positionshould be avoided when the displacement isventral. In both cases reported here, the dis-placement was dorsal. This is expected in frac-tures of the body of the axis because in the dogthe large spinous process lies dorsal to the cau-dal edge of the atlas, consequently contractionof the cervical muscles can only result in dorsaldisplacement of the posterior fragment.The atlanto-axial articulation permits rota-

tion of the head on the spine. Its functionshould be preserved whenever possible. Mostmethods of stabilization of cervical fractures,such as fusion and wiring or plating acrossintervertebral spaces, interfere with the normalmobility of the spine. When applied to articu-lations with such a wide range of motion as the

atlanto-axial joint, normal movement of thehead is severely impaired.

Fractures of the axis of the dog are perhapsbest handled by the application of bone platesto the ventral aspect of the vertebral body.This method affords good stability, is simpleand preserves the normal mobility of theatlanto-axial joint. Fractures of other cervicalvertebrae could also be dealt with in the samemanner.SummaryA simple and efficient method of immobi-

lizing fractured cervical vertebrae is described.It consists of applying finger plates to the bodyof the fractured vertebra by way of a ventralmidline incision. Two cases of fractured axeswere handled by this method and are reportedhere.

ResumeLes auteurs proposent une methode de fixa-

tion de fractures de la colonne cervicale 'a lafois pratique et efficace. Elle consiste a fixerdeux plaques metalliques sur le corps de lavert'ebre fracturee. Pour l'illustrer, deux cas defractures de l'axis ainsi trait6s sont presentes.Acknowledgments

This work is supported in part by the OntarioDepartments of Food and Agriculture.

Radiographs supplied through the courtesy ofthe Radiology Section of the Ontario VeterinaryCollege.

REFERENCES1. ALExANDR, E., JR., C. H. DAvIs and H. F.

FoRisYTH. Reduction and fusion of fracturedislocation of the cervical spine. J. Neurosurg.29: 588-591. 1967.

2. BARTON, L. G. The reduction of fracture dis-location of the cervical vertebrae by skeletaltraction. Surgery Gynec. Obstet. 67: 94-96.1938.

3. BLOCKEY, N. J. and D. W. PURSER. Frac-tures of the odontoid process of the axis. J.Bone Jt Surg. 38B: 794-817. 1956.

4. CONE, W. and W. G. TURNER. Treatment ofcervical fracture - dislocations and fusion. J.Bone Jt Surg. 19: 584-602. 1937.

5. CRUTCHFIELD, W. G. Further observationson the treatment of fracture dislocations ofthe cervical spine with skeletal traction. Sur-gery Gynec. Obstet. 63: 513-517. 1936.

6. DEBURGE, A. Le traitement des fractures etluxations du rachis cervical. La Presse Medi-cale. 75, No. 18, 15 avril 1967.

7. DURBIN( F. C. Fracture-dislocations of thecervical spine. J. Bone Jt Surg. 39B: 23-38.1957.

8. GAGE, E. D. Surgical repair of a fracturedcervical spine in the dog. J. Am. vet. med.Ass. 153: 1407-1411. 1968.

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9. GEARY, J. C., J. E. OLivER and B. F. HOER-LEIN. Atlanto axial subluxation in the canine.J. small Anim. Pract. 8: 577-582. 1967.

10. HoERLEIN, B. F. Traumatic lesions of thecanine spine. Mod. vet. Pract. 39: 24-29.Oct. 15, 1958.

11. HOERLEIN, B. F. Traumatic lesions of thecanine spine. Mod. vet. Pract. 39: 31-36. Nov.1, 1958.

12. HOERLEIN, B. F. Canine Neurology. Philadel-phia, Pa.: W. B. Saunders Company. 1965.

13. HOLDSWORTH, F. W. Diagnosis and treat-

ment of fractures of the spine. Manitoba Med.Review 48: 13-15. 1968.

14. KosINEN, ERmx V. S. and RADMO NIEME-NEN. Fractures and dislocations of the cervi-cal spine. Int. Surg. 47: 472-485. 1967.

15. MuNRo, D. The role of fusions or wiring inthe treatment of acute traumatic instability ofthe spine. Paraplegia 3: 97-111. 1965.

16. NORTON, W. L. Fractures and dislocations ofthe cervical spine. J. Bone Jt Surg. 44A: 115-139. 1962.

ABSTRACTS

Blood, D. C. (1967). Field procedures for thedifferential diagnosis of mucosal disease incattle.-Aust. vet. J. 43, 501-505. Discussionpp. 505-507 (Sch. Vet. Sci., Univ. Melbourne,Parkville, Victoria).

The differential diagnosis of bovine diseasescharacterized by diarrhoea and/or lesions ofthe oral mucosa, is described from the pointof view of the veterinary surgeon in the field.The diseases are classified as (i) diseases withdiarrhoea and oral lesions (bovine malignantcatarrh, rinderpest and mucosal disease); (ii)diseases with oral lesions but without diar-rhoea ("muzzle disease", F & M disease, vesi-cular stomatitis, infectious ulcerative stoma-titis, oral necrobacillosis, infectious papular

stomatitis, and infectious proliferative stoma-titis); (iii) diseases with diarrhoea but nooral lesions (winter dysentery, salmonellosis,copper deficiency, Johne's disease, parasiticgastro-enteritis, coccidiosis, colibacillosis, ar-senic poisoning, an unknown entity in steers,and infection with Cl. perfringens types B andC); and (iv) diseases with lesions on themuzzle but not in the mouth (photosensitiza-tion, and Dermatophilus infection). The ap-pearance of the various types of lesion, andtheir occurrence in the different diseases, arediscussed in some detail in the paper and inthe ensuing discussion.

Reprinted from "The Veterinary Bulletin," Vol.38, No. 9, September, 1968.

Anon. (1968). Great Britain. Ministry of Agri-culture, Fisheries and Food. Department ofAgriculture and Fisheries for Scotland. Reporton the Animal Health Services in Great Britain1966.-pp. 128. London: H.M. Stat. Off. llsOd.

There were 222 cases of ANTHRAX con-firmed in Gt. Britain in 1966, the lowest totalsince 1960. Tuberculin testing of cattle con-tinued at 1- or 2-year intervals, and disclosed3,248 reactors out of 7,141,192 cattle tested.The percentage of reactors was 0.045, aslight decrease on 1965. The "BRUCELLOSISfree herd scheme" was announced in July1966, and wide-scale vaccination of calvesbetween the ages of 5-8 months was en-couraged. In 1966 a total of 925,503 calveswere vaccinated under the "free calf vaccina-tion service", more than in any previous year.A total of 249 cases of suspected FOOT AND

MOUTH DISEASE were investigated, andamong these 34 were confirmed. They resultedfrom two primary foci of infection, one inNorthumberland ("01" type, undeterminedorigin) and one in Sussex ("A22" type, un-determined origin). Vaccination against NEW-CASTLE DISEASE continued, about 80% ofthe national flock being vaccinated. Therewere 194 outbreaks of Newcastle disease (495in 1965, and 2,176 in 1964). SWINE FEVERwas suspected on 963 occasions, and 25 out-breaks were confirmed, a marked drop fromprevious years. The report also gives data onthe import and export of animals, meat inspec-tion and abattoirs, and lists the diagnosis,investigation and research activities of theCentral Veterinary Laboratory Weybridge andthe Veterinary Investigation Service.

Reprinted from "The Veterinary Bulletin," Vol.38, No. 9, September, 1968.

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