Surgical treatment options for hip dysplasia

Hip dysplasia (HD) is thought to be the most commonly diagnosed orthopaedic condition in the dog and, although primarily genetic, environmental factors can have a great bearing on the severity of the disease (Smith et al, 2012).

HD was defined by Henrigson et al (1966) as ‘a varying degree of joint laxity of the hip joint, permitting subluxation during early life, giving rise to varying degrees of shallow acetabulum and flattening of the femoral head, finally, inevitably leading to osteoarthritis’.

Joint laxity refers to the instability which occurs during weight bearing which then leads to subluxation of the femoral head (Smith et al, 2012). In order to create a normal hip joint there needs to be normal load present between the femoral head and the acetabulum. In the dyplastic hip, the constant subluxation of the femoral head from the acetabulum leads to more mechanical load concentrated on the dorsal acetabular rim which in turn will then effect development and can lead to problems such as microfractures of the acetabulum (King, 2017). Osteoarthritis (OA) follows secondary to hip dysplasia due to the ongoing effects of joint laxity if left untreated. In the young dog, in-flammation of the hip joint capsule, abnormal wearing of cartilage and microfractures of the acetabular rim (from the repetitive abnormal load) contribute to the signs of OA (Fries and Remedios, 1995). Although OA cannot be cured, HD can be treated before it progresses to OA.