Sprains and luxations Flashcards
What do ligaments do?
Ligaments Maintain structural alignment of apposing bones in diarthrodial joints
- Extra-articular e.g. collaterals
- Intra-articular e.g. cruciates
What are ligaments?
Longitudinally orientated bundles of collagen fibres
their greatest strength is in tension
How inelastic are ligaments before there is permanent damage?
Very inelastic: > 10% elongation –> permanent damage
What is Desmitis?
Inflammation of the ligament
What are the diagnostic techniques for assessing sprains and luxation?
Careful physical examination
esp. palpation and assessment of joint range of motion / instability
Manipulation
under general anaesthesia
Imaging:
- radiography
- including stressed views (especially cat hocks)
- ultrasound
- arthroscopy
- MRI
- Always check for concurrent injuries
What does this show?
Feline tarsus with a stressed view on far right
What is ultrasound imaging useful for?
Ultrasound
- Requires experienced imager with high resolution machines
- Particularly useful to examine bicipital, gastroc and flexor tendons
What is arthroscopy useful for?
Arthroscopy
- Can examine the intra-articular ligaments such as the cruciates and also those within the joint capsule such as the glenohumeral ligaments of the shoulder
What is CT imaging useful for?
CT
Limited ability to examine soft tissue structures although demonstrates tendon sheath effusions and tendon mineralisation
What is MRI useful for?
MRI
Very sensitive imaging modality with the production of exquisite, detailed images of the joints and associated soft tissue structures
What are first degree sprains?
First Degree:
Few collagen fibres damaged, minimal functional change
•Rest 7-10 days, NSAID ’ s, +/-support –> full recovery in most cases
What are second degree sprains?
Second Degree:
Still grossly intact but > fibre damage, haematoma and functional deficit.
Needs treatment to regain function:
- –Stable –> conservative + support dressing
- Unstable –> imbricate ligament + support dressing
6-10 weeks healing, 3-6 months to regain function
What is imbricating a ligament mean?
Tightening the ligament via surgery
The overlapping of the free edges of a tissue in the closure of wounds or tissue defects
What is a third degree sprain?
Interstitial disruption or avulsion, function completely lost, may not be regained.
Needs treatment to regain function:
- suture repair or ligament replacement
- possible tension banding
- 6-10 weeks healing
- 3-6 months to regain (partial?)
- Joint may ultimately require arthrodesis
What is the generic treatment of sprains?
Treatment
Conservative:
- rest -often months
- reduce swelling (cold packs, massage, medication)
- external coaptation
- support (e.g.Robert-Jones bandage) or bespoke hinged dressing ±
Surgical:
- (a) primary ligament repair
- (b) internal ligament splint / prosthetic replacement
- (c) Immobilisation –transarticular external skeletal fixator
- (d) arthrodesis (salvage)
How would you treat a Plantar ligament degeneration in the dog?
- Not uncommon injury in the Shetland sheepdog and other collies
- Degeneration and subsequent rupture of the plantar ligaments
- Arthrodesis required of the affected joint. Normally subluxation occurs at the level of the proximal intertarsal joint requiring a calcaneoquartal arthrodesis
- Traumatic ruptures seen in athletic dogs (GREYHOUNDS) although this is usually associated with fractures of the hock or as a result of RTA
Discuss carpal ligament injuries?
- Collateral ligament injuries to antebrachio- carpal joint
- Naturally have a degree of valgus therefore medial ligament rupture is most serious and gives rise to valgus deformity. Varus deformities rare as the lateral side is naturally compressed when weight bearing
Discuss carpal hyperextension injuries?
- Usually traumatic –associated with a fall from a height
- Can also be degenerative: Collie types and seen in rheumatoid arthritis
- May be associated carpal bone fractures when traumatic
- Rupture of the palmar ligaments and fibrocartilage
How are carpal hyperextension injuries diagnosed?
Diagnosis
- Characteristic stance
- Careful palpation
- Radiographic examination including stressed views
How are carpal hyperextension injuries treated?
Treatment
- Application of splints and support bandages will fail
- Stressed radiographs will show the level of subluxation but often multiple joints involved or a partial arthrodesis puts strains on the adjacent joints
Therefore pancarpal arthrodesis employed:
- Removal of all articular cartilage, placement of bone graft and rigid fixation with a bespoke plate
- Some form of support required until partial arthrodesis has occurred
Discuss degenerative subluxation seen in cranial cruciate ligament disease in the dog?
- Very common
- Cranial cruciate ligament degenerates / ruptures
- Tibia subluxates cranially relative to the femur
- Various treatment options
- TPLO arguably the best –dogs do well
- Always develop secondary arthritis
What can be seen in these images?
What are the 3 main stabilisers of the hip?
Synovial fluid and surface tension is important too
Describe closed reduction of hip luxation?
Closed reduction ± Ehmer sling
- always radiograph afterwards
- Care with soft tissue injuries & reluxation
- 50% success? Higher with dogs than cats
Discuss the use of the transarticular pin in open reduction of a hip luxation?
Transarticular pin
Most suitable for cats and small dogs
- pin size and position important
- reasonable function, limited adduction
- causes arthritis
- if hip reduction incongruent can damage articular surface
- 2nd procedure to remove implants (3 weeks)
What can be seen here?
Rectus femorisor ilio-femoral suture for craniodorsal luxation
Suture placed through tunnel in base of greater trochanter and either:
- origin of rectus femoris muscle, or
- hole made in ventral aspect of ileum
Suture tightened with hip slightly internally rotated
May cause slight internal rotation of paw –resolves when suture fails several weeks later
What can be seen here?
Hip toggle -canine
- quite challenging surgery
- can still cause articular damage if hip not congruent
- if properly inserted –> very stable, functional joint
- braided multifilament suture within joint –> appreciable risk of infection
What can be seen here?
Treat ASAP:
- -always GA
- -pre-op radiographs -include thorax
Closed or open reduction
Check collateral ligaments (in elbow they are often not broken)
Post-operative radiographs!
What can be seen here?
Congenital elbow luxation
- Different types associated with breed size
- Can be treated conservatively if the dog is coping
- Surgery can be beneficial, but residual lameness common
