“To arthrodese or not to arthrodese” is the question I asked myself when I tuned into this week’s webinar on carpal and tarsal injuries. As we encounter these injuries relatively frequently in practice it is surprising this topic is not covered more often at CPD events, and I was hoping that some light could be shed on the diagnosis and treatment of these sometimes challenging cases.
And after listening to the highly respected speaker, Professor John Innes BVSc PhD CertVR DSAS(orth) MRCVS from Liverpool University, I was not disappointed.
Diagnosis of carpal injuries can be challenging and mulitple modes of diagnosis are often necessary, including a thorough clinical examination with carpal instability being best assessed under sedation. Synovial fluid sampling is also useful and relatively simple to perform by fully flexing the carpus and inserting the needle into the antebrachiocarpal joint.
Radiography is a necessity but John warned us that fracture lines can sometimes be missed.
Hyperextension of the carpus is one of the most common carpal injuries seen in practice and is often associated with either a fall from a height, or as a degenerative condition in specific breeds such as the Sheltie and Rough Collie.
Treatment for this condition involves performing a partial or pan carpal arthrodesis, and according to John, for all of us out there who are good at plating fractures, a carpal arthrodesis is well within our reach. Puppies can also suffer from a laxity syndrome which generally does not require surgery and resolves over time.
John was also keen to discuss fractures of the radial carpal bone, a condition seen in boxers which appears to develop spontaneously and is thought to be secondary to a developmental abnormality of the carpal bone. Boxers present with carpal swelling and no history of trauma or injury. Generally these cases don’t do well and require pan carpal arthrodesis.
The diagnostic tools used for carpal injuries can also be used for tarsal injuries with the addition of ultrasound playing an important role in diagnosing injuries to the achilles tendon and gastrocnemius.
Once again beware of radiography missing more complex fracture lines such as those seen in central tarsal bone fractures, a condition seen in Greyhounds, working dogs and, anecdotally, in Dalmatians. These fatigue fractures are often fixed with lag screws and John believes that cases may not do as well as expected due to missed comminuted fractures on x-ray. Performing a CT scan could prevent these more complex fractures being missed.
Plantar ligament degeneration was also discussed and is another condition seen in both Shelties and Rough Collies. Interestingly, John has observed that this breed-related condition is not seen on the continent, appearing to be specific only to the UK.
Calcaneoquartal arthrodesis is the best treatment option for this condition. Although John was keen to stress this was not a painful condition and if an owner has limited funds, not performing surgery was a reasonable option as long as the dog did not go on to develop further problems such as pressure sores.
Throughout this webinar John discussed many more tarsal and carpal conditions alongside surgical techniques and I would highly recommend logging on to his webinar in the archive section to view this invaluable advice.
To conclude John provided us with some key ‘take home’ messages;
Carpal and Tarsal injuries are common injuries seen in practice
Carpal and tarsal fractures can be challenging. If you can’t feel instability or see a fracture on x-ray then consider performing a CT scan
Many injuries will lead to osteoarthritis
Arthrodesis is a reasonable option for many of these injuries
Of course this last point answers my original question at the beginning of this interesting and informative webinar.
By The Stethoscope