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
Outline key points to sprain injuries?
- Different degrees of ligament damage
- Prolonged rest and long recovery (physiotherapy)
- will predispose to joint damage + osteoarthritis
- May result in joint sub-luxation or luxation
- In severe cases, may have to arthrodese (fuse) the joint
Define a normal joint?
Cartilage surfaces in contact
Define a luxated joint?
Luxated joint
- cartilage surfaces not in contact (character of luxation i.e. medial or lateral is taken from the position of the distal articular surface)
Define a subluxated joint?
Subluxation
- partial contact of cartilage surfaces
Define incongruent?
Incongruent = abnormal shape to bones and cartilage
Define Dysplasia
Abnormal development
What terminology can be applied to luxations?
- Traumatic (common)
- Congenital (rare)
- Developmental (frequent) e.g hip and elbow dysplasia
Describe acquired/traumatic luxations?
Associated with 3rd degree sprain (ligaments), joint capsule and other peri-articular structures damaged
- results in traumatic arthritis
- individual ligaments may never heal
- capsule thickens to assume some function of the supporting ligaments
- +/-surgery –> restore acceptable function, or –>salvage procedure
Discuss congenital luxations?
Congenital luxations-rare
- Malformation of joint, bone or soft tissue
- Often severe associated bone deformity
- may be symmetrical
- relation with luxation and formation of joint
- E.g. congenital elbow luxation, small breed dog Luxated joint results in abnormal shape to the articular surfaces
- Congenital luxations seen in shoulder of small breeds –congenital elbow luxation seen in the Staffie
What are the treatment options for congenital luxations?
Treatment:
Limited options
- Conservative –the patient may cope
- Surgical restoration can be attempted but unlikely successful
- Salvage e.g. arthrodesis, joint replacement or amputation
- Guarded prognosis with surgery
Surgical reduction can be attempted but not uncommonly fails due to the misshapen articular surfaces
Discuss developmental subluxations/incongruencies?
Developmental subluxations / incongruencies
Very common
- Hip dysplasia / elbow dysplasia
- Elbow incongruency maybe the primary disorder of fragmented coronoid process, osteochondrosis dessicans and ununited anconeal process
- Commonly bilaterally symmetrical
- Relation between subluxation and formation of joint
- Develop secondary arthritis
Treatment:
- Conservative / medical management of arthritis
- Salvage surgical procedures:
- Joint Replacement / Arthrodesis / Excision
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
Where are luxations possible in dogs and cats?
Dogs and cats: any joint possible
- hip and tarsus common
- patella luxation -intermittent
How should luxations be assessed?
Clinical examination ( ± GA)
- pain
- asymmetry
- Laxity- this may depend of the chronicity of the condition. With time periarticular fibrosis and muscle contraction can stabilise the joint
- Orthogonal radiographs of limb +/-thoracic and abdominal radiographs if traumatic luxation
- +/-stressed views of joint
What are the principles of repair of traumatic and acquired luxations?
- Reduce joint into normal anatomical alignment, and maintain the reduction while the capsule and other soft tissues heal.
- Primary repair of capsule or ligaments frequently impossible or too weak
- Avulsion: re-attach bone
- Prosthetic ligament or strengthening of capsule
- Post-operative support (as for sprains)
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
Describe open reduction of hip luxation?
Open reduction and stabilisation
Always include soft tissue repair / imbrication (PDS)
- transarticular pin
- toggle
- rectus femoris or ilio-femoral suture
- ? 75 -85% / success
Salvage procedure – replacement or excision
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
What are the key points about luxations?
Luxations: always radiograph before and after reduction
Acquired luxations:
- reconstruct the supporting structures if possible
- support the repair
- physiotherapy improves recovery
- OA / DJD is inevitable
Subluxations
- developmental / degenerative
- very common
- medically manage if mild
- salvage surgery if not coping
Congenital luxations:
- Very rare
- poorer prognosis
- Grossly dysplastic joint
- Often better left alone
