Hip dysplasia is a general term used to describe any abnormality during normal development of the hip. These changes are usually present at birth, but also childhood and adolescence, and lead to modifications in its normal anatomy at adult age. The hip is a ball and socket joint formed by the head of the femur (ball) and the acetabulum (socket) that admits very little alterations in its normal anatomy to be able to offer an adequate function. Therefore, any little distortion within its shape will predetermine a loss of function that, if left untreated, will result in joint wear or osteoarthritis. In conclusion, hip dysplasia is a children’s condition that may remain undetected until the adulthood, when it starts off with symptoms that, to certain point, are related with the joint wear.

Hip dysplasia can be classified attending to its degree, which depend mainly on the lack of normal coverage of the femoral head by the acetabulum. Today, most severe dysplasias (the greatest degree) are diagnosed right after birth by using different tests for early detection. In contrast, it is common that a mild or border-line dysplasia (the lowest degree) remains undetected until an age between 30 and 40 years old when symptoms of mechanical conflict start off.

Symptoms:

The patient affected with hip dysplasia is typically an adult female (even though it can also affect males) of around 35-40 years old, who presents with pain and discomfort around the groin and/or buttock area. In addition, the patient reports a recent stiffness within the hip, complaining of not being able to achieve the range of motion she/he had some time ago. Occasionally, symptoms like clicking, limping and sense of instability are also present. These symptoms are not exclusive of hip dysplasia; hence it is mandatory to perform imaging tests.

Diagnosis:

The most simple and fastest test to detect hip dysplasia during adult age is the pelvis X rays, which show a lack of coverage or “roof” of the femoral head within its socket in the pelvis. Very commonly, early signs of hip osteoarthritis are detected in association with the diagnosis of dysplasia. Some patients who were treated of severe dysplasia during the childhood that could not be fully corrected may also present with these early symptoms of hip outwear.

However it is not needed for the diagnosis, magnetic resonance imaging may be useful for detecting abnormalities within the labrum and articular cartilage. CT scan of the hip can also be useful for better understanding the anatomy of the hip when planning a surgery.

Normal hip and hip displasia

Treatment:

The treatment of hip dysplasia of the adult depends on the degree of misshaping of the hip itself, together with the presence of signs of osteoarthritis. In patients under 35 years old who don’t present with arthritis the aim of the treatment is achieving a hip preservation surgery. The procedure that repositions the acetabulum to a mechanically optimal position within the pelvis is called periacetabular osteotomy (PAO). For this, the pelvis is cut with a saw or osteotomes and brought to a shape as close as possible to normal, fixing it with screws. The goal of this surgery is to relieve symptoms and to increase the life span of the joint. PAO is a very complex procedure that, even though can be performed through a minimally invasive approach, requires a thorough planning and a supervised recovery.

Hip arthroscopy consists of a minimally invasive technique that allows for correcting joint damage by using a special camera inside the joint and several instruments especially designed for this. In addition, labrum and articular cartilage injuries can be also treated. This camera shows directly the hip joint so that any kind of problem within the tissues can be detected and treated through only 2 or 3 additional accesses or portals (incisions of only a few millimeters long). Arthroscopic surgery avoids open surgery, offering advantages in terms of postoperative pain and recovery. Hip arthroscopy is an effective tool for repairing structures like labrum and assessing articular cartilage, nevertheless it is not a technique than should be broadly used for cases of hip dysplasia as the mechanical conflict cannot be solved with its use.

In cases in which there are already signs of hip osteoarthritis, hip preservation surgery comes out usually with poor results. Hip replacement should be, therefore, the preferred procedure. There are special options for younger patients that offer a better function meant for maintaining a more active lifestyle that last over time.