mature lame animal 1 Flashcards
What signalment is common in mature lame animals?
- Elbow dysplasia:- Labradors. Rottweilers, Bernese mountain dogs, Newfoundlands
- Humeral intracondylar fissure:- spaniels
- Infraspinatus contracture:- spaniels
- Lateral patella luxation:- Flat coat retrievers
- Medial patella luxation:- many small breeds including the French bulldog and occasional Labrador and English bull terrier
- Lumbosacral disease:- German shepherd dog
- Neoplasia:- large and giant breeds
- Cellulitis:- the outdoor un-neutered male cat
How is the type of lameness helpful to narrrow down the cause?
Acute lameness:
* sprains
* acute cruciate rupture
* fractures both pathological and traumatic
* cellulitis
Chronic lameness:
* osteoarthritis
* humeral intracondylar fissure
* nerve root tumour
Intermittent:
* patella luxation
* dislocation of the tendon of origin of the long digital extensor
* superficial digital flexor instability
Acute on chronic:
* cruciate rupture
* pathological fracture
* condylar fracture subsequent to HIF
What should you focus on in your clinical exam of the mature lame animal?
- Reduced or increased range of movement and swelling to joints
- Instability to joints or associated sesamoids e.g. patella
- Pain and crepitus on manipulation of joints
- Pain or crepitus on palpation of the long bones and joints or soft tissues
- Muscle atrophy (follows the pattern of innervation?)
- Neurological deficits
What further investigations can be undertaken in the mature lame animal?
- Radiography:- still the mainstay of investigations of the lame small animal
- CT:- especially of the elbow and shoulder
- MRI:- spine, nerve roots, stifles and shoulder
- Joint taps:- detection of septic arthritis and polyarthritides
What animals are likely to have patella subluxation?
- A common condition
- Less frequently seen in the cat (traumatic but also developmental in Abyssinian and Devon Rex)
- Often asymptomatic
- Common in small breeds e.g. Yorkshire terriers, poodles, French bulldogs, Cavalier King Charles spaniels
- Also seen in English bulldogs and Labradors
- Lateral patella subluxation reported in the Flat coated retriever
Why is the shoulder prone to soft tissue conditions?
The shoulder is innately unstable
It relies on soft tissues for stability
- Muscles:- supra- infra and subscapularis and teres minor
- Tendons:- biceps tendon of origin
- Ligaments:- medial and lateral glenohumeral
As a result of this it is prone to sprains, particularly the medial glenohumeral ligament and other soft tissue injuries
The biceps tendon can become inflamed or rupture:- bicipital tendonitis
A specific condition seen in working dogs is infraspinatus contracture
How can we diagnose soft tissue conditions of the shoulder?
Palpation of the shoulder
* Any pain elicited?
* Biceps tendon test (apply pressure to the bicipital groove whilst retracting the shoulder and extending the elbow) Is there any pain elicited by this procedure? If it is possible to extend the elbow greater on one side? This is indicative of either biceps tendon rupture or avulsion (tearing of the tendon from its bony origin)
* Manipulation under general anaesthesia (there is some debate as to how useful this test is) The degree of abduction and adduction can be measured but is a little subjective
Radiography:
- mineralisation of the infra and supraspinatus tendons. are these significant findings? Rely on clinical examination
Ultrasound:
- particularly useful to examine the biceps tendon. A high frequency linear or hockey stick transducer is the appropriate probe
CT and MRI:
- both can be useful. CT requires contrast enhancement. cf. the elbow
Arthroscopy:
- the gold standard. Allows management as well as diagnosis
How are soft tissue conditions in the shoulder treated?
- Treatment options are limited in the management of soft tissue injuries around the shoulder
- Rest and NSAI are often beneficial but the time taken for any sprain to the collateral ligaments can be long.
- The medial collateral is often the sprained ligament and it can be imbricated with sutures or lightly cauterised to induce scarring and stability. Neither treatment appears effective
- There are particular conditions of the bicipital tendon including a tenosynovitis which can be treated with intra-articular corticosteroids or sectioning (cutting) of the tendon which appears to make little difference to the dogs ability to walk. The cut tendon can either be left or the tendon attached to the proximal humerus with a spiked washer and screw (tenodesis)
- Removal of mineralised parts of the tendons of insertion of the supra and infraspinatus muscles can, on occasions, improve any lameness but these are often incidental findings and therefore the significance of the changes can be difficult to assess.
What is an infraspinatus contracture? How is it treated?
- A relatively rare condition
- Seen primarily in working breeds such as the springer spaniel
- A progressive condition
- Characteristic limb posture
- Managed by sectioning the tendon close to its insertion on the humerus
- The prognosis is good
What signalment and clinical signs are associated with humeral intracondylar fissures? How are they diagnosed? How is it treated?
Signalment
* Spaniels including the Brittany, springer and Cavalier King Charles
* Common in the French bulldog although a recent study shows that when this condition is seen in the young dog they will go on to fuse when an adult
* Young to middle aged dogs with no sex predilection
Clinical signs
* Chronic forelimb lameness or acute if associated with lateral, medial or bicondylar fracture
* Muscle atrophy and elbow swelling
* Pain on manipulation of elbow and when pressure applied across the condyle
* Acute lameness associated with condylar fracture more often seen in the young puppy- very common in the French bulldog with minimal trauma e.g. jumping from a sofa or from the owner’s arms
Diagnosis
Radiography
- Multiple views required to be at right angles to the fissure in order to demonstrate the lesion
CT
* This is the modality of choice. There may be a fissure or initially an area of sclerosis within the condyle.
* It is important to appreciate that contrary to initial assessment of these cases, this condition may not be a failure of the capitulum and trochlea of the condyle to fuse but one which can develop in the mature animal
* Some recent studies suggest that it may be another manifestation of elbow incongruity resulting in the anconeus engaging on the caudal intercondylar region resulting in a stress fracture
Treatment
Conservative management
- Rest and non steroidals but always the risk of a condylar fracture with significant morbidity
Surgical management
- Placement of large transcondylar screw (4.5mm in most spaniels and 5.5mm in Labradors)
- This is prone to a significant number of complications although a recent study has suggested that the complication rate is less than initially reported
- Seroma formation and infection around the screw head
- Breakage of the screw
- Inadvertent penetration of the joint
- These can be minimised by placing the screw from medial to lateral (more difficult) and placing the screw as a lagged implant rather than positional although the compression of the fracture site can lead to joint incongruence
- CT produced templates can be used to aid screw placement
These fissures probably never heal hence the need for the strongest implant, i.e. screw with the greatest core diameter
What is the most common carpal injury?
Hyperextension injuries
* Dog or cat jumps over a wall with a large drop the other side
* The palmar ligaments and palmar cartilage are damaged irrevocably
* Carpus is swollen with varying degrees of palmargrade stance
* Can occur as a result of a destructive arthritis (rheumatoid)
How is carpal hyperextension diagnosed? How is it treated?
Radiographs determine the level of the injury (stressed views helpful)
* Antebrachiocarpal
* Intercarpal
* Carpometacarpal
* This may not matter as generally a pancarpal arthrodesis is used to treat this condition (all the joints are fused)
Treatment
* Partial or pancarpal arthrodesis, i.e. joint fusion as the ligaments will neither heal or be capable of repair
* Partial arthrodesis is rarely performed as it results in strain on adjacent joints
Which dogs are affected by stenosing tenosynovitis of the abductor pollicus longus? How do they present? How are they diagnosed? How are they treated?
- Chronic lameness seen in large exuberant dogs
- Pain on carpal flexion
- Soft tissue swelling medial carpus
- Boney exostoses seen over the medial aspect of the radius in chronic cases
- Ultrasound will demonstrate changes to tendon and increased fluid in the tendon sheath
- Treat with steroid injection into the tendon sheath, freeing the tendon or sectioning tendon (tenotomy) although the latter has been associated with marked degeneration of the carpus and is not recommended
What occurs in plantar ligament degeneration? How do animals present? How is it diagnosed? How is it treated?
- Collies, particularly Shetland sheepdogs
- Insidious onset
- Proximal intertarsal subluxation with bilateral changes
- Degeneration progresses to rupture and plantigrade stance
- Clinical and radiographic diagnosis with proximal intertarsal subluxation
- Treat with laterally applied plate and arthrodesis of the calcaneoquartal joint.
- No further immobilisation required other than a support bandage for a week
What tarsal injuries do racing greyhounds get?
- rarely race again
- predominantly a right limb injury as in the UK these dogs race anti-clockwise
- combination of subluxations and fractures
- Medial aspect of the joint collapses with fracture to central bone (several types with its own classification system)
- Fractures and subluxations occur of the calcaneus and calcaneoquartal joint
- a specialist injuries requiring referral
How does gastrocnemius tendinopathy present? How is it diagnosed? How is it treated?
- older Labrador retrievers and Dobermanns
- chronic hind limb lameness
- often bilateral
- relatively common
- painful swelling to Achilles tendon and mineralisation on radiographs
- characteristic clawing of foot due to lengthening of gastroc but not the SDF tendon - claw like stance
- Treatment:- resect tendon and place calcaneal tibial screw or transarticular external fixator to support the repair or a pantarsal arthrodesis
How do open traumatic carpal and tarsal injuries occur? How should they be managed?
- These arise from trauma particularly road traffic accidents
- Accompanied by varying degrees of soft tissue damage and contamination
- Manage the soft tissue injuries first
- A temporary external fixator may help in the initial stabilisation of the joint
- Many of these injuries will require arthrodesis to manage
- Other than the talocrural and antebrachiocarpal joints all others are low motion joints
- Loss of low motion joints results in minimal loss of function
How does a superficial flexor luxation present? How is it treated?
- An uncommon condition (but most commonly seen in the Shetland sheepdog) - usually latera
- Intermittent lameness with an audible popping sound and sensation
- Swelling over the tip of the calcaneus
- Treatment can be
- Either suturing the torn retinaculum but recurrence is not uncommon
- Screwing the SDF to the calcaneus
