The carpus, the joint on the front limb that is the equivalent to the wrist, is a complex joint that is susceptible to ligament injury, or sprain. These injuries often cause instability in the joint. Management of injury often includes rest and sometimes bandaging. If the dog does not respond to rest, sometimes surgery (arthrodesis, or fusion of the joint) is offered.
Maintaining cage rest can be difficult for both dog and owner. Immobilization with bandages can result in decreased strength in healing ligaments and can have adverse affects on the joint cartilage. However, allowing full range of motion in an unstable joint can result in unsatisfactory healing.
An alternative treatment is a custom brace. A brace eliminates the need for strict cage rest. It also allows partial joint loading while limiting joint instability.
Below is a recent study that looked at whether or not a brace could be used to manage carpal ligament injury in dogs that had front limb lameness caused by carpus sprain.
Evaluation of application of a carpal brace as a treatment for carpal ligament instability in dogs: 14 cases (2008-2011)
Tomlinson, JE. Manfredi, JM. JAVMA, 244 (4), 438-443, 2014
What They Did:
The authors reviewed medical records of all dogs with evidence of carpus instability that were examined at a rehabilitation veterinary clinic between 2008 and 2011. Of 910 records reviewed, 14 dogs were admitted to the study. Twelve of the 14 dogs were active in agility, one was a herding dog, and one was a family pet. Each dog had had a history of carpus pain and instability that had failed to respond to forced rest.
Each dog was fitted with a custom-made, neoprene brace (Thera-Paw) that stabilized the carpus but still allowed limited flexion and extension. Each dog wore the brace for a minimum of 8 weeks.
Each dog received physical rehabilitation to maintain range of motion and to strengthen the limb, and to gradually decrease dependence on the brace during controlled activities.
What They Found:
Eleven of 14 dogs returned to normal function.
Eleven of 12 dogs returned to agility competition.
Besides its function in movement, the carpus functions as a shock absorber for the front limb. When the carpus is completely immobilized, whether temporarily with bandaging material or permanently through surgery, it loses both of these functions.
A brace that allows for some movement and partial weight bearing through the joint is a good way to stimulate healing of the ligaments while limiting excessive motion and preventing further injury.
This study did not include dogs that had hyperextension injury to the carpus. However, it might be worthwhile to attempt bracing in a dog with that injury prior to recommending surgery, depending on the size of the dog and the degree of hyperextension.
This study discusses dogs that have carpal instability due to injury. Some dogs have carpal instability for other reasons, such as immune-mediated arthritis or chronic repeat injury. Dogs with chronic conditions may need a brace that provides more stability (either a neoprene brace reinforced with thermoplastic or a custom-made orthotic) and may need to rely on the brace for support for entire life of the dog. For some owners whose dog may need a brace forever, surgery may be a more practical option.
All the dogs in this study also received rehabilitation as part of their recovery. This is important for maintaining range of motion as well as staging strengthening exercises to avoid reinjury. Dogs that were involved in a sporting activity received additional supervised training for 4-6 weeks after the brace was removed.