Both hip dysplasia and hip impingement (femoroacetabular impingement, or FAI) are, in fact, major causes of osteoarthritis in the young adult hip and often result in the need for surgical reconstruction or replacement of the joint (a procedure called arthroplasty) at a young age.
A matter of biomechanicsMedically speaking, hip dysplasia is related to a change in the biomechanics of the hip that leads to axial overloading with a decreased contact area and increased contact pressures with maximum loading at the rim or socket.
FAI is characterized by abnormal contact of the ball-shaped head of the femur in the hip socket, which can damage cartilage and restrict movement. With FAI, instead of the femoral head being shaped like a baseball in the socket, it’s more like a football. Sometimes the hip shape abnormalities are quite small, but even these, over time, can lead to decreased range of motion and abnormal contact between the femoral head and socket. Continued impingement can lead to labral tears and cartilage damage. If the cartilage and labrum become too damaged, early arthritis of the hip is the likely result.
The hip is the purest ball-and-socket joint of the body. Because of this, the hip has an amazing axis of rotation, allowing you to move in an almost 360-degree manner. There is a delicate balance between too much motion and too little motion. Both can lead to early arthritis. It’s fascinating that the majority of hip arthritis cases are due to problems related to the biomechanics of the hip, or in other words loss of that balance of motion.
In addition to hip dysplasia and FAI, a variety of structural hip conditions – including Perthes disease and slipped capital femoral epiphysis – lead to adverse hip mechanics that can likewise ultimately lead to pain and arthritis.Joint preservation surgery for these conditions is often a desirable option compared to total hip replacement because of the associated possibility for the need for early surgical revision and wearing out of the hip replacement.
The goal of hip preservation surgery is to preserve a patient’s native joint, improve hip function, and eliminate pain. Treatment is specific to each patient’s hip and can consist of physical therapy, intraarticular injections, nutrition, and surgery.
Surgical intervention can include hip arthroscopy and open hip surgery. Sometimes the pelvis or femur needs to be realigned or reshaped. A tailored approach is very important because not all hip pain is the same, and certain treatments may actually hurt one type and help another.
Another goal of hip preservation surgery is to help stop or delay arthritis and allow adolescents and young adults to stay more active and healthy. Correcting hip mechanics can, and often does, get rid of the pain and improve the joint’s longevity.
Sometimes hip reconstruction and not hip preservation is warranted. Depending on the patient’s anatomy, new minimally invasive hip reconstruction and replacements are available. Direct anterior total hip replacement and mini posterior hip replacements allow patients to recover quicker, have less pain postoperatively, and become more active sooner.