The hip is composed of two bones, the head of the femur (ball on top of thigh bone) and the acetabulum (socket) that is a portion of the pelvis. The ends of these bones that move about each other have a layer of cartilage, which forms the surface of the joint. Dysplasia of the hip is best described as an underdeveloped acetabulum (socket) that is not deep enough to support a healthy environment for the cartilage. Hip dysplasia can affect children as young as newborns and is usually screened for at the time of birth with the Ortolani and Barlow maneuvers. Treatment for children may include casting or potentially surgery.
Hip Dysplasia in adults
The hip dysplasia that is noted in adult patients is generally considered a developmental dysplasia of the hip that gradually changes during one’s childhood. Here the acetabulum is under-developed and is noted to be shallow. This leaves a small amount of cartilage on the socket to bear the weight of the body. The labrum is a lip of tissue surrounding the hip socket that will usually grow larger, hypertrophy, in order to try to accommodate for the under-developed acetabulum. The cartilage and labrum will eventually become damaged because of the abnormal stress they are repetitively seeing. Some treatment is aimed at repairing damaged cartilage and labrum if the dysplasia is not bad enough. Severe cases of dysplasia will be better suited for a periacetabular osteotomy or PAO surgery. The PAO surgery entails creating osteotomies, fractures, around the acetabulum and reorienting it so that there is more acetabular cartilage covering the femoral head. In severe cases where there is extensive cartilage damage, a patient may be a better candidate for a minimally invasive anterior approach total hip replacement.
Discomfort and pain are described by patients as a dull, aching throb that is deep in the hip. This typically is located in the groin fold in front of the hip and will radiate down the front of the thigh toward the inner aspect of the knee and toward the buttock region. In fact, many patients may have the sensation that their knee hurts; however, it may just be radiating pain from hip joint problems. Many will also describe a sharp, stabbing type of pain that is equilibrated to being “stabbed by an icepick”. Pain can also elicit a feeling of weakness in the muscles around the hip, which can result in the leg buckling or giving way. The pain typically increases whenever the hip joint is bent during activities like squatting, sitting and stairs. Athletic activities such as running and jumping, which require hip flexion, will also aggravate these symptoms. Activities that also require rotation through the hip, such as golf and pickleball may also increase these symptoms. A person’s range of motion, or movement, of the hip will also be affected. This effectively decreases ones ability to fully bend or straighten the hip. Patients typically have difficulty tying shoes or picking up objects from low-lying places.
In severe cases, a person may be able to feel or hear the hip joint moving and grinding. This may be a result of damaged cartilage and bone moving about each other or perhaps from loose fragments floating in the hip or a flap from a concomitant labrum tear catching on the overlying bone.