Shoulder Osteochondritis Dissecans (OCD)
What is Osteochondritis Dissecans (OCD)?
Osteochondrosis Dissicans (OCD) is a developmental condition that arises due to a disturbance in the normal differentiation of cartilage cells resulting in failure of endochondral ossification (essential process during foetal development of skeletal system resulting in bone formation).
In dogs that grow very quickly, the rapid cartilage growth can outstrip its own blood supply causing abnormal cartilage development resulting in lameness, pain and subsequent osteoarthritis. In some cases, flaps of diseased cartilage become separated from the remaining cartilage surface. This is called Osteochondritis Dissecans.
Is there a particular breed predisposition?
Genetic factors are the most important cause of OCD, with strong breed predispositions, particularly in Labradors and giant breed dogs. Different breeds appear to be predisposed to developing the condition in different joints. For example, the shoulder joint is most commonly affected in Border Collies, Great Danes and Irish Wolfhounds. Various other factors such as dietary or nutritional problems during the first few months of life, hormonal imbalances and joint trauma can also increase the risk of developing OC.
How do I know if my dog has OCD?
Most dogs with OC/OCD start to show clinical signs before they are 1 year old, although occasionally (particularly with shoulder OC) signs may present when your dog is older. The clinical signs are variable and depend on the joint affected and the size of the cartilage defect. The most common signs include lameness, stiffness, joint pain or swelling, reluctance to exercise or play, or general depression.
How is shoulder OCD diagnosed?
OCD is typically diagnosed following a multimodal evaluation process. Firstly your dog will be examined by one of our orthopaedic clinicians, following this your dog will be admitted to the hospital to allow radiographs of the affected joints under sedation or general anaesthesia. As osteochondrosis (OC) can occur at the same time as other developmental orthopaedic diseases (such as certain manifestations of elbow dysplasia), some dogs may require additional diagnostic imaging such as CT or MRI which will be performed by our advanced diagnostic imaging team. Your dog will receive one-to-one nursing care throughout the process by one of our nurses from the prep nursing team who are all highly trained and experienced in anaesthesia and sedation. Following diagnostic imaging, your dog may require surgery to allow arthroscopy (keyhole surgery) to be performed on the affected joint.
Will my dog develop osteoarthritis?
As soon as OCD starts to develop, osteoarthritis (inflammation of the joint and associated bones) immediately starts to develop. Once present, osteoarthritis cannot be cured but can be effectively managed in most patients.
How is shoulder OCD treated?
Various treatment options are available for shoulder OC/OCD. The best treatment option for each dog can only be recommended following thorough clinical, radiographic and arthroscopic assessment. Non-surgical management is occasionally appropriate for dogs with small cartilage defects and minimal discomfort, however, the majority of dogs are treated surgically. The following options are available:
Surgical removal of the cartilage flap
Certain types of small cartilage defects in specific locations are treated arthroscopically by flap removal and debridement of the defected bed. This allows the cartilage defect to heal by scar cartilage formation over a course of several weeks. Scar cartilage (fibrocartilage) is less robust than healthy joint (hyaline) cartilage, so although this allows some of the joint inflammation to resolve in the short-term, the joint will remain abnormal with ongoing development of osteoarthritis and cartilage wear. We currently recommend this surgery for very small or shallow disease lesions.
Osteochondral autograft transfer (OAT)
Historically we adopted the OATS™ (Arthrex, Naples, FL) system for use in the canine shoulder joint. This system has been used for many years in human joints to resurface cartilage lesions including OCD with positive long-term results. It involves the collection of a cylinder of bone and cartilage from a non-contact area of a healthy joint (usually the knee) and transplanting it into the joint affected by OCD in order to resurface the cartilage defect with healthy hyaline cartilage.
Synthetic osteochondral resurfacing (SOR)
More recently we have implemented a synthetic resurfacing which means we do not have to harvest graft from the patient thus making the procedure less painful. The synthetic graft is constructed from polycarbonate urethane (PCU). PCU is used in the manufacture of heart valves, stents and replacement lenses to name but a few of its medical applications.
Manufactured by Arthrex, SynaCart represented the cutting edge of treatment for canine OCD. The implant is a second generation synthetic osteochondral resurfacing implant, which incorporates the polycarbonate urethane of the SOR implant mentioned previously and combines this with a trabecular titanium metal, which allows bone to grow into the implant.
Your orthopaedic clinician will advise you on the best course of treatment for your dog.