Carpus and Tarsus Flashcards
Describe the carpal collateral ligaments
- all are short ligaments
- connect adjacent bones only
Describe the tarsal collateral ligaments
- long portion spans the entire tarsus on each sire, and is taut in extension only
- short portion crosses the joint obliquely, provides rotational stability, and is taut in flexion and extension
How is collateral injury assessed?
- position limb in extension
- apply valgus and varus stress to the joint
- examine tarsus in flexion and extension
- abnormal motion indicates injury
Which views are used to assess collateral injury on radiograph?
- dorsopalmar and lateral
- dorsoplamar stress views (valgus and varus)
How is collateral injury treated?
- ESF if there is soft tissue trauma
- collateral ligament replacement
Describe how collateral ligament replacement is performed
- screw or bone tunnel at the origin and insertion of each ligament
- create a tunnel and thread the suture through
- figure 8 pattern
What occurs in a hyperextension injury?
- damage to palmar or plantar support ligament
- allows abnormal motion between rows of carpal/tarsal bones
What is palmar fibrocartilage?
the confluence of joint capsule and ligaments on the palmar surface of the carpus
Which breeds are predisposed to hyperextension injury?
shelties and collies
What are the possible causes of hyperextension injury?
- trauma (HBC)
- immune-mediated
- breed-related
Describe the presentation of hyperextension injury
- swollen, painful joint
- less pain and swelling with chronic injuries
- hyperextended stance (dropped hock)
How are hyperextension injuries treated?
- splint application and rest (unhelpful alone)
- arthrodesis
Describe a partial carpal arthodesis
- middle and carpometacarpal joints are fused using T-plate or pins
- function is retained
Describe a pancarpal anrthodesis
- all 3 carpal joints are fused
Describe a partial arthrodesis of the calcaneoquartal
- lag screw placed at end of calcaneous and extended down the joint
What needs to be done post-arthrodesis?
- coaptation (splint or ESF)
- activity restriction until bony fusion
What components make up the common calcanean tendon?
- gastrocnemius tendon
- combined tendon of the gracillus, semitendinosus, and biceps femoris
- SDF tendon
How does the dog present with a partial rupture of the calcanean tendon?
- SDF usually preserved
- Partial hyperflexion of the hock
- flexion of the digits
How is a rupture of the calcanean tendon treated?
- debride tendon ends
- primary tendon repair with 3-loop pulley
- immobilize tarsus in extension
Which methods of coaptation are use post op for ruptured calcanean tendon?
- eternal fixator
- splint
- giant lag screw
Which breed is predisposed to tarsus OCD?
Rottweiler
Where is the lesion usually located in OCD of the tarsus?
- ridge of the talus
- medial most common
- lateral in rottweilers
What are the clinical signs of OCD of the tarsus?
- lameness, worse after rest
- hock-extended stance
- joint effusion/fibrosis
- pain/crepitus on manipulation
What is seen on radiograph of a dog with OCD of the tarsus?
articular flattening
lucency
Which radiographic views are used to assess OCD of the tarsus?
flexed lateral - expose proximal talus
flexed craniocaudal - cranial trochlear ridges
When is medial therapy indicated for OCD of the tarsus?
older dog with established osteoarthritis
What surgical treatment is done for OCD of the tarsus?
- fragment excision/debridement
- tibiotarsal arthrodesis
What is the prognosis for OCD of the tarsus
guarded to poor
When is tarsocrural arthrodesis indicated?
- severe injury to tibiotarsal joint
- failed calcanean tendon repair
- osteoarthritis non-responsive to medical therapy
How is tarsocrural arthrodesis performed?
- fuse tibiotarsal joint at a standing angle
- remove articular cartilage
- pack with bone graft
- rigid fixation (type 2 ESF or plate)
