J . small Anim. Pruct. (1978) 19, 363-371.

Elbow lameness in the young dog caused by a sesamoidal fragment

M A R I A V A A N A N E N A N D K A I S K U T N A B B Department of Surgery, College of Veterinary Medicine, Helsinki

A B S T R A C T

Intermittent lameness in 8 dogs was attributed to a sesamoidal fragment in the elbow joint. The clinical signs, diagnosis and treatment of the condition are described.

I N T R O D U C T I O N

Several papers dealing with injuries in the elbow joint as causes of intermittent lameness in the front leg have appeared during recent years. The main cause of arthrosis in young fast-growing dogs is considered to be the osteochondrosis syndrome (OD) (Olsson, 1974), which includes:

( I ) Osteochondrosis dissecans proc.ancon. ( 2 ) Osteochondrosis dissecans proc.coronoid.med. (3) Focal O D of the medial epicondyle of the humerus. Several authors have recognized a sesamoidal fragment on the lateral aspect of

the el bow (Tirgari, 1973; Grondalen 1973; Prole, 1973; Webbon & Clayton Jones, 1976) and queried its significance. Prole and Clayton Jones consider the fragment as being part of the normal anatomical structure which does not cause intermit- tent lameness or arthrosis. Grondalen & Braut (1976) reported the finding of a fragment bilaterally on the medial side, which they considered to be the cause of arthrosis. Long & Roger (1977) reported a similar case.

C A S E H I S T O R I E S

Eight dogs were presented a t 6 months of age with slight (2-3 degree) intermittent

0020-45 I0/78/0600-0363$02.00 0 1978 BSAVA

363

3 64 M . V A A N A N E N A N D K . S K U T N A B B

foreleg lameness. The case details are summarized in Table 1. The cause of lameness was not always apparent. Medial rotation (varus) of the forelimb occurred when the sesamoidal fragment was on the lateral side of the joint. The severity of lameness increased with time. The joint became swollen and there was pain on palpation of the lateral collateral ligament over the head of the radius. It was not usually possible to elicit crepitus in the joint nor was there pain on palpation of the proc.anc0neu.s or proc.coronoideus. The presence of the sesamoi- dal fragment was confirmed by radiographic examination and treatment was by surgical excision.

RESULTS

Radiographic examination Technique. The elbow is X-rayed in lateral and antero-posterior positions.

Moreover, the radius has to be rotated somewhat 50" laterally from the A-P position. The X-ray beam should pass between the head of the radius and the sesamoidal bone.

In normally used A-P position of the elbow joint the sesamoidal bone is superimposed at the lateral head of the radius. (Kv 50 MAS 10 High Speed) (Figs 1 and 2).

FIG. 1. Elbow joint, lateral radiographic anatomy.

Findings. In each case the rotated A-P view of the elbow revealed a dense fragment on the lateral side of the proximal head of the radius, (Figs 3 and 4). The surface of the fragment was smooth and the size varied between 2 x 2-5 x 5 mm in diameter. There was no radiographic evidence of arthrosis in typical places where it is seen when OD is concerned. There were no fractures on the radius and the fragment seemed to be totally independent.

TABLE

I.

Age

at

Dat

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ate

onse

t In

term

itten

t lam

en.

Rad

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gica

lly

of

Com

plic

. Fr

ee fr

om

Cas

e of

of

sym

ptom

s 1-

4"

foun

d fr

agm

ent

oper

at:

in w

ound

- H

isto

logy

sy

mpt

oms

No.

B

reed

bi

rth

Sex

(mon

ths)

Le

ft R

ight

D

egre

e Le

ft R

ight

19

77

heal

ing

sam

ple

I wee

k 2m

onth

s

4

Rot

twei

ler

Lab

rado

r re

triev

er

Ber

nese

m

ount

ain

Ber

nese

m

ount

ain

New

- fo

undl

and

Ger

man

sh

ephe

rd

Ger

man

sh

ephe

rd

Rot

twei

ler

dog

dog

7.8

Q 75

6.

6 d

74

1-8

Q 76

7.11

Q

75

29.7

Q

28.4

d

76

76

5 17 5 5

x I

X

3

X

2

X

3

xx

3

xx

2

X

3

X 3

X

X

4.2

S.C.

oe

dem

a -

X

15.3

+

X

X

23.3

+

X

+ X

X

25

.3

-

+ x

X

X

13.4

-

X

X

noto

p.

-

-

-

X

X

2.9

S.C.

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dem

a in

lab

X

X

25.5

-

rn r

m 0

€ r

m

z rn m

m - Z 4

T rn .(

0

C

Z 0

U 0

Q

366 M . V A A N A N E N A N D K . S K U T N A B B

FIG. 2. The X-ray beam should pass between the head of the radius and the sesamoidal bone. This will be attained by rotating the radius from A-P position 50" laterally.

FIG. 3. The left elbow of a German Shepherd, 9 months old. The sesamoidal bone can be seen laterally a t the proximal head of the radius.

E L B O W L A M E N E S S I N T H E Y O U N G D O G 367

FIG. 4. In normally used A-P position of the elbow joint the sesamoidal bone is superim- posed at the lateral head of the radius.

S U R G I C A L P R O C E D U R E

Approach to the elbow joint A skin incision 2 cm long is made over the lateral surface of the elbow joint and

extended through the subcutaneous fascia (Fig. 5) . The skin and the fascia are undermined and retracted. The deep antebrachial

fascia is bluntly dissected and cut between the common and lateral digital extensor muscles. The muscles are separated over the joint to expose the joint capsule and lig. collaterale lat. The sesamoidal bone can be palpated cranially to the ligament (Fig. 5) .

A cut is made in front of the sesamoidal bone with a tenotomy blade and/or small scissors. The sesamoidal bone is then dissected from the collateral ligament and the joint capsule to which it is attached (Fig. 5).

The joint capsule is closed with absorbable synthetic suture material 2-0, (Dexon@). The deep antebrachial fascia and subcutaneous tissue are closed by the same means with interrupted sutures. The skin wound is sutured with Wolf-U, using nonabsorbable suture material. The joint can be flushed with dihydrostrep- tomycin 250 mg/ml before closure.

368 M. V A A N A N E N A N D K. S K U T N A B B

(C)_

Lq. col bterole loterolis

Epicondylus humeri loterolis

I

Surgical results Clinically, intermittent lameness decreased clearly one week after the operation

and lameness has resolved in five patients so far. The follow-up has been rather short but up to now the results are encouraging.

P A T H O L O G Y

The fragments were bony, 2 x 2-5 x 5 mm in diameter. The area towards the joint was covered with smooth cartilage. The opposite side was usually covered with connective tissue originating from the joint capsule and the ligament from which

E L B O W L A M E N E S S I N T H E Y O U N G DOG

FIG. 6. Magnification of the sesamoidal bone showing the lamellar bone centre.

FIG. 7. Magnification of the bone, showing the articulating surface.

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370 M . V A A N A N E N A N D K . S K U T N A B B

it was removed. The fragments were decalcified and stained by haematoxylin (H and E) and van Gieson methods.

Histology The fragments were covered by fibrous articular cartilage that resembled hyalin

cartilage in places. The centre of a fragment consisted of lamellar bone. A small, more or less necrotic, focus inside the centre was found in the case of the patient which developed arthrosis. There were no signs of necrosis or degeneration in any of the other fragments. Nor could callus-formation be shown on any of the fragments. All of the specimens contained small amounts of connective tissue, possibly originating from the joint capsule, (Figs 6-8).

FIG. 8. Magnification of the bone showing the nonarticulating side.

DISCUSSION

Obviously fragments of this kind must be considered, together with the osteo- chondrosis-syndrome, which Olsson ( 1977) has so widely described, as causes of intermittent lameness in the elbow joint. The occurrence of the fragment does not necessarily cause lameness but symptoms may become apparent through some external stimulus.

There has been no arthrosis and the fragments have been shown, both histolo- gically and radiographically, to be of a non-fracture origin. (Therefore they cannot be considered avulsion-fracture from an osteophyte.)

E L B O W L A M E N E S S I N T H E Y O U N G D O G 371

At the operation typical OD-foci were not encountered, nor was there any radiological evidence of OD. Histologically, the fragments did not resemble typical OD-fragments. Therefore neither O D of the proc.anconaeus nor of pro- cxoronoideus can be the cause.

It is difficult to determine the origin of the fragments, but i t cannot be excluded that they could be sesamoidal by nature. They are attached to the joint capsule and in a certain phase of the joint movement (flexion) they may be interposed between the joint surfaces and thereby cause intermittent lameness. This view is supported by the clinical observation that the patients try to move in such a way that the joint-space is as wide as possible.

A C K N O W L E D G M E N T

The authors wish to thank the Department of Anatomy at the College of Veterinary Medicine of Finland for technical and scientific assistance.

R E F E R E N C E S GRONDALEN, J. Malformationoftheelbowjoint inan Afghan hound litter. J.smallAnim. Pract. 14,2. GRONDALEN, J. & BRAUT, T. (1976) Lameness in two young dogs caused by a calcified body in the

LONG, R.D. & ROGER, A.J. (1 977) Letter to the editor, J. small Anim. Pract. IS, 157. OLSSON, S.-E. (1974) En ny typ av armbagsleds dysplasi hos hund? Svensk vet tidskrift. 26, 152. OLSSON, S.-E. (1977) Osteochondros hos hund. Svensk Vel . tidskrift 13-14, 547. PROLE, J.H.B. ( I 973) Letter to the editor. J. small anim. Pract. 14,309. TIRGARI, M. (1 974) Clinical radiographical and pathological aspects of arthritis of the elbow joint in

WEBBON, P.M. & CLAYTON JONES, D.G. (1976) Radiological refresher-6. The elbow. J . small

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