SA Ligamentous and Tendinous Conditions Flashcards
Ligament structure.
Short bands of tough fibrous tissue:
- bind bones of body together.
- hold structures in places (e.g. transverse humeral ligament hold biceps tendon in place).
Dense regularly orientated CT.
Fibres (collagen), cells (fibroblasts), ground substance.
Ligament injuries.
Types and their management.
Healing?
Known as sprains.
Divided into 3 types.
- Type I = minimal w/ some haemorrhage, manage w/ rest, bandage 2w.
- Type II = partial tearing and stretching of fibres w/ haemorrhage, manage w/ sx repair w/ suture or protect w/ prosthetic, external coaptation post op.
- Type III = complete rupture or avulsion of attachment, manage w/ sx repair +/or prosthetic replacement, ESF or external coaptation post-op. Arthrodesis e.g. palmar carpal ligament rupture.
Slow healing - need protection.
– 3w rigid support.
– then 3w flexible support.
Primary repair often not possible as become fibrillated and cannot hold suture.
Collateral ligament injuries aetiopathogenesis.
Traumatic - RTA, fall.
Any joint can be affected:
- shoulder, elbow, stifle (often closed injury).
- hock, carpus (can be open or closed).
Valgus vs varus.
Causes of valgus/varus.
Valgus = distal part of the limb deviates laterally.
Varus = distal part of the limb deviates medially.
Causes:
- bone deformity, ligament laxity, injury.
Collateral ligament rupture dx.
palpation, clinical signs.
Radiographs.
- stressing the foot by pushing or pulling the foot into varus or valgus to test ligament integrity.
Tx of collateral ligament injuries.
Type I:
- conservative – bandage, rest, NSAIDs etc.
Type II/III:
- collateral ligament repair / replacement.
- anchor points at origin and insertion.
– anchor using screws and washers.
– anchor using suture anchors.
– suture replaces ligament.
Avulsion fracture.
- repair w/ pin and TBW.
Post-op:
- external skeletal fixator / external coaptation.
Open ligament injury.
Tx.
Degloving / shear (type III).
Open wounds w/ loss/damage to collateral ligaments.
Tx - open wound management
– flush/debride/analgesia.
- provide stabilisation (bandage / splint / ESF).
- collateral instability may not need specific tx – fibrosis may be sufficient to restore stability.
- severe injury – amputate.
- salvage – arthrodese.
Rupture of plantar/palmar ligaments.
In hock and carpus.
Aetiology = trauma/degenerative.
Pathogenesis = ruptured ligament causes loss of function / luxation / subluxation.
Signalment = shetland sheepdog / collie types predisposed.
Clinical signs = plantigrade / palmigrade stance, lameness.
Dx = palpation, stressed radiographs.
Tx = ligaments are short so tension is high so repair failure is likely.
- the joint is low motion so tx of choice would be arthrodesis (partial or pan).
Px = good w/ appropriate tx
– arthrodesis.
Dislocation / luxation / subluxation.
Luxation = complete dislocation.
Subluxation = partial dislocation.
Congenital = uncommon. Reported in shoulder and elbow at young age.
Acquired = Major trauma e.g. RTA, falls. Significant ST damage has to occur to allow dislocation. Will be ligament ruptures and poss. muscle and tendon ruptures. Any joint affected. Open or closed.
Salvage procedures.
Operation that allows continuance of function of an animal w/o preservation of normal anatomy. E.g. arthrodesis, amputation, excision arthroplasty e.g. FHNE, prosthetic sx (total hip replacements).
Arthrodesis.
Sx joint fusion.
Relieves pain, restores function.
Joint disease that might benefit from arthrodesis:
- chronic unrelenting joint pain.
- untreatable articular fractures.
- chronic joint luxations.
- partial neurological injuries.
- unreconstructable ligament injuries.
Sx principles of arthrodesis?
Debride - / remove cartilage.
Angle - stabilisation at an appropriate angle for the joint – avoid angulation/rotation. Measure angle of ‘normal’ joint prior to surgery.
Graft - placement of cancellous bone graft.
Immobilise - affected joint preferably under compression.
Which joints can be arthrodesed in the dog and cat?
Good px:
- distal joints – carpus and to a lesser degree the tarsus are arthrodesed w/o significant effect on gait of animal.
- animals can do well after shoulder arthrodesis and ROM lost by arthrodesis is gained by increase in motion in the muscles holding the scapula to the trunk (synsarcosis).
Poor px:
- arthrodesis of elbow and stifle results in significant alteration in gait w/ circumduction of the limb to compensate for the ‘long lever arm’ and inability to now flex these major joints.
- arthrodesis of hip contraindicated.
Amputation indications.
What must be done before amputation?
neoplasia, severe pain, dysfunction beyond repair, osteomyelitis, neuro injury e.g. plexus avulsion, fracture / wound / injury that cannot be treated (e.g. for financial reasons).
Examine whole animal especially other joints to ensure suitable for amputation one leg.
Amputation levels.
- considerations to make when deciding on level of amputation.
Thoracic limb = disarticulate shoulder, proximal humerus, remove whole limb plus scapula.
Pelvic limb = disarticulate hip, proximal femur, hemipelvectomy.
- consider reason for amputation, margins (neoplasia), cosmetics, cut through bone / joint.
– concerns around irritation.
