Re: Shepherd with elbow click

[Guest guest]

Sylvie,

This sounds like classic " jump down syndrome " or traumatic fragmented medial

coronoid process…………acute lameness, clean radiographs, medial compartment

sensitivity, and intermittent click………….I would scope the elbow asap before it

causes secondary cartilage erosion…….bit more information below:

Traumatic Fragmented Medial Coronoid Process

Traumatic fragmented medial coronoid process (TFMCP) is a condition in the elbow

joint of dogs that appears to occur commonly in performance and working dogs.

Unlike the classic condition of fragmented medial coronoid process (FMCP)

affecting the elbow joints of skeletally immature large to giant breed dogs,

jump down syndrome (TFMCP) appears to have no age or size limitations.

Cause

The cause and pathogenesis of TFMCP are poorly understood. It is possible that

abnormal repetitive loading, such as landing from a jump, hitting contacts or a

flyball box, and so on, may lead to microfractures of the bone underneath the

cartilage (subchondral fractures). Additionally, increased repetitive loading

can arise from contraction of the biceps/ brachialis muscle complex. When the

biceps/brachialis contracts, a force is generated that rotates the medial

coronoid into the radius. These microcracks disturb the mechanical properties of

bone, and if not repaired properly through normal body mechanisms, fatigue

fractures develop. Additionally, loss of osteocytes (bone cells), indicated by

decreased osteocyte densities, has been strongly associated with the presence of

microdamage after fatigue loading. These studies imply that excess load may

lead to fatigue microdamage of the subchondral trabecular bone and eventual

fracture, which we believe may play an important role in the pathogenesis of

TFMCP. Dogs may be further predisposed to this condition if they have elbow

dysplasia. Dogs with elbow dysplasia had asymmetric growth of the radius and

ulna during development, resulting in elbow joint incongruity. Elbow incongruity

such as radioulnar step defects, humeroulnar incongruence/conflict, and varus

deformity of the humerus causes abnormal contact patterns in the elbow,

specifically at the coronoid trochlear articulation, which is theorized to

increase the load on the medial coronoid process (MCP). Regardless of the

etiology, if left untreated as a continual lameness, secondary osteoarthritis

may progress as noted by damage to the cartilage such as softening,

fibrillation, fissuring, and erosions as well as additional subchondral bone

microcracks and fragmentation. The free fragments contribute to frictional

abrasion ( " kissing lesions " ) of the opposing surface including the medial aspect

of the humeral condyle and radial head.

Diagnosis

History and Clinical Signs

Dogs with TFMCP may present with a history ranging from a subtle intermittent

offloading of the forelimb to significant unilateral or bilateral forelimb

lameness. This lameness is typically exacerbated with exercise and heavy

activity. The onset of lameness is insidious. As lameness persists, it may

increase in severity. Affected dogs often place the carpus in an exaggerated

valgus position (turned out) when sitting or standing, and circle the foreleg

outward and move the elbow away from the midline (circumduct the antebrachium

and abduct the elbow) during the swing phase of the stride. The history of dogs

with TFMCP typically includes a lack of response to rest and non-steroidal

anti-inflammatory drugs (NSAIDs). Many dogs with TFMCP are mistakenly treated

for shoulder pathology because the attending veterinarian elicits a pain

response when the shoulder is extended. The authors believe the pain response

actually arises from the elbow because when the veterinarian performs an

extension maneuver of the shoulder, the elbow is usually simultaneously

extended. Extension of the shoulder and elbow causes tension in the

biceps/brachialis muscle complex. Tension in the biceps/brachialis exerts

pressure on the medial coronoid and overlying inflamed joint capsule causing the

pain response.

Orthopedic Examination

On physical examination discomfort is usually noted on direct palpation of the

medial compartment of the elbow joint, specifically the medial coronoid process.

Discomfort may also be noted on hyperflexion of the elbow. Most dogs with TFMCP

are reluctant to allow for full endrange flexion. In chronic cases, full flexion

may not be obtained. Crepitus may be noted when placing the elbow through range

of motion. Some investigators suggest that the carpus should be placed in a

flexed, externally rotated position while the elbow is extended. Joint effusion

may be detected as a fluctuant swelling beneath the lateral or medial epicondyle

of the humerus. Depending on the chronicity, atrophy may be noted in the

affected forelimb.

Advanced Diagnostics

In addition to history, gait analysis, physical examination, orthopedic and

neurologic examinations, further diagnostic tests used to differentiate causes

of elbow pathology currently consist of hematology, biochemical profile,

urinalysis, arthrocentesis, imaging modalities, and arthroscopy. Unfortunately,

radiographs have been shown to be of little value because of difficulty

identifying the fragment or line of separation using standard radiography. In

some chronic cases, however, radiographs may reveal secondary evidence of bony

remodeling consistent with osteoarthritis. These changes may include sclerosis

within the ulnar notch, and remodeling along the anconeal process and MCP.

Advanced diagnostic imaging modalities such as CT scans, MRI, nuclear scans, and

arthroscopy may allow confirmation of the condition. Arthroscopic evaluation

of the elbow joint allows direct observation of all major intra-articular

structures with magnification, " dynamic " evaluation of tissues during elbow

range-of-motion tests, and " palpation " of intra-articular tissues using

arthroscopic instrumentation. Arthroscopic exploration of the elbow provides a

definitive diagnosis of TFMCP when a fragment or cartilage fissure. In a small

percentage of cases, advanced imaging (nuclear scan, CT, MRI) indicates

fragmentation of the coronoid but arthroscopic observation does not reveal a

fissure or fragment. In such cases, the fissures (microcracks) are believed to

be within the coronoid bone beneath the cartilage surface.

Treatment

Treatment of TFMCP is multimodal and includes a combination of medical and

surgical management as well as rehabilitation therapy. Through a multimodal

approach it is possible to relieve pain and maintain limb function, as well as

to return the dog to a normal level of activity and competition.

Arthroscopy is an excellent modality for diagnosing TFMCP as well as a minimally

invasive means of treatment. Arthroscopic removal of the fragments is

recommended not only to remove the inciting cause of lameness but also to help

prevent/slow the progression of osteoarthritis. Arthroscopic treatment may

include a combination of techniques such as fragment removal, debridement of

diseased tissues, creation of vascular access by abrasion arthroplasty, forage,

microfracture, and subtotal coronoid ostectomy depending on the progression and

severity of disease. Arthroscopy is not only a great diagnostic modality,

allowing for superior visualization of structures within the joint, but also has

less soft tissue trauma, shorter surgery and hospitalization times, decreased

risk of infection, and shorter recovery times compared to the traditional

surgical approach of fully opening the joint (arthrotomy).

Following arthroscopic treatment, dogs are typically prescribed NSAIDs for 14

days to help decrease inflammation and discomfort. Polysulfated

glycosaminoglycans (PSGAG) an injectible joint protective agent, is also

recommended following arthroscopic treatment and is administered intramuscularly

twice a week for up to four weeks. PSGAGs has been shown to decrease the amount

of degradative enzymes (that stimulate inflammation and cartilage erosion) as

well as promote repair and regeneration of cartilage. In addition, an oral

joint protective agent such as glucosamine, chondroitin sulfate, and

avocado/soybean unsaponifiables (ASU), is recommended as a daily supplement for

life. The anti-inflammatory properties and pain-reducing effects of these

supplements have been well-documented. There is also evidence that they may

have a cartilageprotective effect.

As with any rehabilitation therapy program, elbow rehabilitation following elbow

arthroscopy should follow a sequential and progressive multiphased approach.

The ultimate goal of elbow rehabilitation is to return the patient to their

previous functional level as quickly and safely as possible. However, each case

is uniquely different, and several factors; including duration of

injury/lameness prior to surgery, secondary osteoarthritc conditions, surgical

intervention performed, all influence the rate at which the patient proceeds

through the healing process.

The elbow is predisposed to flexion contractures due to the intimate congruency

of the joint articulations, the tightness of the joint capsule, and the tendency

of the anterior capsule to develop adhesions following injury. The

biceps/brachialis complex also attaches to the capsule and crosses the elbow

joint before becoming a tendinous structure and inserting on the ulnar

tuberosity. Injury to the elbow may cause excessive scar tissue formation of

the brachialis muscle as well as functional splinting of the elbow.

Reestablishing full elbow extension is the primary goal of early ROM activities

to minimize the occurrence of elbow flexion contractures.

Additional goals of this stage are to protect healing tissue, decrease pain and

inflammation, restore weight bearing and retard muscular atrophy. The

rehabilitation therapist must not overstress healing tissues during this phase.

It is important that the owner restrict the dog's activity to short leash

walking only with no running, jumping and rough play.

Hope this helps.......please let me know if you need help finding a surgeon in

your area that scopes....

Happy Halloween!!!

Sherman

Sherman O. Canapp Jr., DVM, MS, CCRT

Diplomate ACVS

Diplomate ACVSMR

Veterinary Orthopedic &

Sports Medicine Group

10975 Guilford Road

polis Junction, MD 20701

Phone:

Fax:

http://www.vosm.com

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> I recently examined a new patient, a 4 year old male German Shepherd, for

> evaluation of a subtle R foreleg lameness which the owner feels has been

> present for a couple of years on & off and which seems worse after heavy

> exercise, particularly when he has been " rough housing " with her other dog.

> This dog is lean but big (43 kg) and is used for herding and bomb detection.

> He has never been evaluated by a veterinarian for this problem. We could

> not detect any lameness, so we did a gait analysis (corn starch test) which

> confirmed a slightly shortened stride on the R fore. I couldn't feel any

> abnormalities or elicit any kind of a pain response on examination of the R

> foreleg. There was normal ROM of all joints however he did have a

> repeatable audible " click " at end extension of the R elbow. I can feel a

> ropey structure (medial collateral ligament?) on the medial aspect of the

> elbow joint whose movement seems to coincide with this click.

>

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> His elbows were x-rayed and sent to a radiologist for interpretation and the

> report came back as " subtle and minimal degenerative changes in both elbows,

> probably not severe enough to account for clinical signs " . (This dog also

> had his elbows evaluated by the OFA at 2 years of age and they were found to

> be clean).

>

>

>

> I have tried to research this " click " as the owner is curious and would like

> a diagnosis, but have not had much luck. Has anyone else ever come across

> this and, if so, are you able to clarify for me what is likely happening and

> what we should do about it? I realize that the lameness may be unrelated.

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> Thanks to anyone who can shed some light on this for me!

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> Sylvie Abrioux, DVM, CCRT

>