When is total hip replacement necessary for hip dysplasia?
Sometimes, total hip replacement is the best answer for hip dysplasia. Mainly when arthritis is severe, or for people older than 45-50 years. Hip dysplasia has unique features that need special techniques for the hip replacement surgery to be as successful as possible. For surgical planning, hip dysplasia is usually classified from mild to severe with Type 1 being the least involved and Type 4 the most severe. Type 4 is when the hip is completely dislocated, and completely dislocated hips are generally referred to major hip replacement centers because these are rare and need the most experienced surgeons.
Lesser degrees of dysplasia still require special attention to get the best results. The anatomy of a dysplastic hip is different from the anatomy of other types of hip arthritis. The socket is more shallow than normal and may not be in the normal location. The upper part of the thigh bone may be small or abnormally shaped, and the legs may not be the same length. Previous surgical procedures during childhood may also cause difficulty in planning and performing a total hip replacement.
Placement of the socket is perhaps the most important part of total hip replacement for patients with hip dysplasia. The best results are usually obtained when the socket is placed as close as possible to the normal anatomical location. Pre-operative planning is especially important because dysplastic hips may be at a higher location than normal and need special techniques to be brought down to the normal level. Deepening of the socket is almost always needed and may require careful cracking of the inside wall of the pelvis combined with bone grafting to make sure the socket is placed deep enough that there is a good bone roof over the artificial socket.
Additional considerations are whether to use cement to hold the artificial parts in place, or whether to use special methods that allow bone to grow into the artificial parts without cement. This is especially important in hip dysplasia because patients tend to be younger than patients with other types of arthritis. In young patients there are some benefits to avoiding the use of cement if possible. Also, younger patients may need different types of surfaces for their artificial joints. Currently, the preferred artificial joint surfaces for young people tend to be ceramics, or metal on modern polyethylenes.
If you need a total hip replacement for hip dysplasia, it’s a good idea to go to an experienced surgeon. Fortunately, there are many but that’s because hip dysplasia is more common than most people realize. You should be able to find a good hip replacement surgeon near you. Please review our list of questions [http://hipdysplasia.org/developmental-dysplasia-of-the-hip/tips-for-parents/questions-for-your-doctor/] you might want to ask the surgeon to help you decide whether he’s the right surgeon for you.
A recent update for doctors was published as a series of papers in a review journal called Orthopedic Clinics of North America. Here are the references in case your doctor is interested.
Acetabular considerations during total hip arthroplasty for hip dysplasia.
Femoral considerations for total hip replacement in hip dysplasia
Technical considerations in total hip arthroplasty after femoral and periacetabular osteotomies.
Bearing surface considerations for total hip arthroplasty in young patients.