Hip Dysplasia

Canine hip dysplasia (CHD) can be a debilitating disease of the hip joint. In orthopedics, the term dysplasia refers to abnormal development or formation of musculoskeletal tissues, including bones and joints. Hip dysplasia is a common condition in which there is abnormal development or malformation of the hip joint, leading to instability, pain, and eventually osteoarthritis. Hip dysplasia is a genetic disorder and can first be identified in puppies as young as five to six months of age.

Etiology and Pathogenesis – Causes of Hip Dysplasia

Canine hip dysplasia (CHD) is a multifactorial condition with a complex etiology (cause) involving both genetic and environmental factors. It primarily affects dogs, particularly large and giant breeds, although smaller breeds can also be affected. Known contributors to canine hip dysplasia include:

• Genetic Factors: Genetics play a role in the development of hip dysplasia. The condition has a hereditary component, meaning it can be passed down from parent dogs to their offspring. Dogs with a family history of hip dysplasia are at a higher risk of developing the problem. Even if a dog has certified hips (e.g., obtained through screening such as hip scoring), they may still carry genes associated with hip dysplasia.
• Joint Conformation: The conformation of the hip joint, including its shape, size, and laxity of the ligaments and muscles surrounding it, influences whether hip dysplasia develops. A shallow acetabulum (hip sockets) and laxity in the joint predispose a dog to hip dysplasia.
• Environmental Factors: Factors such as rapid growth rate, obesity, improper nutrition (including overfeeding or feeding a diet high in calories), inappropriate exercise (such as concussive activities at a young age), and excessive stress on the joints during growth can exacerbate the condition or increase the likelihood of hip dysplasia.
• Hormonal Factors: Hormones can affect the growth plates and when they close as well as bone remodeling processes. This can contribute to abnormal joint development.

It’s important to note that while genetics and conformation are significant risk factors for hip dysplasia, other factors influence the presence, severity and progression of the condition. Responsible breeding, proper nutrition, proper exercise, and weight management are important in reducing the risk of hip dysplasia in dogs.

Clinical Signs of Canine Hip Dysplasia

Dogs with hip dysplasia can present with a range of clinical signs. These can vary significantly in severity depending on the extent of joint laxity, how the joint fits, the degree of osteoarthritis, and the age of the patient. Clinical signs associated with canine hip dysplasia include:

• Difficulty Rising: 
• Decreased Range of Motion (stiffness): 
• Pain
• Muscle Atrophy
• Bunny Hopping
• Crepitus (clicking or grinding from the joint)
• Lameness (limping)
• Reluctance to jump
• Reduced desire to play
• Behavioral changes

Treatment Options for Hip Dysplasia

There is no cure for hip dysplasia nor is there a cure for osteoarthritis that develops as a result of hip dysplasia. Having said this, there are both conservative non-surgical options as well as surgical interventions that can be considered.

Conservative Non-Surgical Options for Hip Dysplasia

• Weight Management – This is the #1 most important aspect of management of hip dysplasia or any dog with osteoarthritis
• Minimally or non-concussive activity – swimming minimizes the concussive nature of activity while still providing activity
• Regular and consistent activity – staying consistent with activity can help these dogs. Multiple shorter walks will be better than a single long walk every day.
• NSAIDs – anti-inflammatory medications help reduce pain and inflammation associated with the joint
• Supplements/Nutraceuticals – Omega 3 fatty acids (fish oils) have been shown to reduce inflammation. Other nutraceuticals may help but the evidence for many are lacking.
• Physical therapy – therapeutic exercise can help maintain flexibility and strength. Underwater treadmill therapy can provide significant calories expenditures while providing some “float”. Modalities such as laser therapy or e-stim can be considered as part of PT.

The above are considered first tier management of any patient with osteoarthritis. There are numerous other options that might be discussed or indicated as a patient progresses through their lifetime.

Surgical Options for Hip Dysplasia:

• Juvenile Pubic Symphysiodesis (JPS): JPS is a surgical procedure performed in young dogs to address hip dysplasia. It is typically done in puppies between 3 and 5 months of age, well before skeletal maturity is reached. JPS is a preemptive procedure aimed at tethering the pubis to improve conformation/coverage of the hip and reduce the risk of hip dysplasia.
• Double Pelvic Osteotomy (DPO): DPO can be considered in dogs under eight to nine months of age. Double pelvic osteotomy involves making two osteotomies (bone cuts) in the pelvic bones that allow the acetabulum to rotate over the femoral head. The new position of the acetabulum is secured with a bone plate and screws. Before undergoing DPO, the surgeon determines whether the dog is a suitable candidate for DPO. It is important to use stringent criteria for which dog is a good candidate. Given the success of total hip replacement, dogs must successfully meet several requirements to have success with DPO. If your dog is younger than nine months of age, your surgeon will help you determine if DPO is a viable procedure.
• Femoral Head Ostectomy (FHO): Femoral Head Ostectomy involves removal of the femoral head (ball) and portion of the femoral neck from the joint. Scar tissue forms between the remaining femur and acetabulum (socket) forming a pseudoarthrosis. This “false joint” removes the source of pain in many patients, but many continue to have a mechanical limp as removing the joint alters the patient’s anatomy. The primary advantage of the FHO is lower cost and the procedure is typically reserved for cats and small dogs.
• Total Hip Replacement (THR): THR is a highly effective surgical option for dogs with hip dysplasia who have been poorly responsive to conservative management. It provides substantial pain relief and restores near-normal hip joint biomechanics, allowing affected dogs to lead active and comfortable lives. The procedure removes the diseased joint and a prosthetic hip joint consisting of a metal femoral stem acetabular cup is implanted to replace the removed joint components. Improved implant systems over the last 30 years have led to the reduction of complications. THR can also be offered to smaller patients.