VM 569 Conditions of the Canine Carpus and Tarsus (Day 6, part 4)
What is the treatment for carpal hyperextension? (3)
-Arthrodesis -Pancarpal arthrodesis if the radiocarpal joint is involved -Partial carpal is not recommended, only used if there is a sound radiocarpal joint
What is used for thorough articular cartilage debridement? (4)
-Burr -Curette -Rongeur -Bleeding subchondral bone is the bone
What are the structures that are radiographically visible in the canine tarsus? (4)
-Calcaneus (yellow) -Talus (orange) -Tarsal bones (1-4) -Central tarsal bone (green)
What are the typical clinical findings in a dog with carpal hyperextension? (5)
-Carpal hyperextension -Near palmigrade -Swelling of affected carpus -Palpable joint effusion -Pain on carpal flexion and extension
What joint is most affected in carpal hyperextension? (3)
-Carpometacarpal - most commonly affected -Middle carpal -Radiocarpal
What are the ligaments involved in the tarsus? (3)
-Collateral ligaments -Short tarsal ligaments -Plantar ligaments and fibrocartilage
What are the ligaments involved in the carpus? (2)
-Collateral ligaments -Palmar ligaments and fibrocartilage
What is the prognosis for dogs with carpal hyperextension with conservative and surgical treatment? (2)
-Conservative - poor prognosis -Arthrodesis - good prognosis
What do the collateral ligaments of the tarsus control? How many components are there collateral ligaments?
-Control valgus/varus and rotation -3 components
What is the classic breed for common calcaneal tendinopathy? (1)
-Dobermans, but can be seen in medium/large breeds
What is carpal hyperextension due to? (2)
-Failure of palmar ligaments and fibrocartilage -NOT tendon failure
What are the ultrasound findings in a dogs with a common calcaneal tendinopathy? (3)
-Hyperechogenicity (increase whiteness) in the middle of the tendon (fibrosis) -Core lesion (hypoechoic) in the middle of the fibrosis -Loss/disorganization of the fiber pattern
What are indications for arthrodesis? (5)
-Luxations/ALD -OA/fractures -Hyperextension injury -Radial nerve injury -Neoplasia
What are the radiographic findings in a dog with common calcaneal tendinopathy or calcaneal tendon laceration? (2)
-Osteophytes or roughening over the calcaneus bone -Soft tissue swelling
What is the emergency first-aid treatment for a patient with a traumatic calcaneal tendon laceration? (3)
-Primary repair of the common calcaneal tendon involves direct apposition -Important to have little tension as possible, or failure is more likely -With degenerative conditions, large resections of the tendon might be needed, meaning primary repair may not be ideal
What are the clinical findings in a dogs with common calcaneal tendinopathy? (5)
-Severe lameness -Plantigrade stance -Curling (hyperflexion) of the toes (due to intact superficial digital flexors) -Increased flexion of tarsus with stifle extended -Soft tissue swelling
What is the function of the plantar ligaments and fibrocartilage?
Prevent hyperextension
How is carpal hyperextension diagnosed on radiographs? (1)
Stress view radiographs
What are the common historical findings with carpal hyperextension? (2)
-Usually secondary to a jump/fall -Dropped carpus
What are the two main causes of common calcaneal tendinopathy? (2)
-Acute (laceration) -Chronic/degenerative
What is the treatment for a patient with common calcaneal tendonopathy? (3)
-If trauma - suture end together -If degenerative - excise abnormal parts of the tendon and suture the tendon together -Lock hock in extension using a screw or frame
What is used for rigid fixation in arthrodesis? (4)
-Plate -Pin -Screws -External skeleton fixation (ESF)
What are methods of arthrodesis? (2)
-Plate (preferred methods) -Hybrid plates - tapered distally, 5 degree pre-designed "bend"
What are the joints involved in the carpal functional anatomy? (3)
-Radiocarpal joint (yellow) -Proximal intercarpal joints -Carpometacarpal joint (bluish)
What are the joints present in the canine tarsus? (4)
-Talocrual/tibiotarsal joint (yellow) -Proximal intertarsal joints (blue) -Distal intertarsal joints (green) -Tarsometatarsal joints (white)
What are the principles of arthrodesis? (6)
-Thorough articular cartilage debridement -Autogenous cancellous graft (bone graft) -Rigid fixation -Preservation of soft tissues -Compression/close contact of all joint surfaces you are fusing -External coaptation (splinting, bandages, casts)
What are the typical historical findings in a dogs with common calcaneal tendinopathy? (5)
-Trauma (laceration) -Lameness -Swelling at insertion of tendon -Hyperflexion of hock -+/- knuckling of the digits