The hip joint is a ball and socket joint made of the head of the femur (ball) and acetabulum of the pelvis (socket). The joint is stabilized by surrounding soft tissue structures. If the femoral head is loose in the socket, or if either the femoral head or acetabulum is deficient, the hip point can become uneven, less rounded, or incongruent, which can lead to arthritis and pain.
Hip dysplasia is defined by a spectrum of physical and imaging findings (abnormality in the size, shape, orientation or organization) involving the socket, the femur or both. The hip may be unstable (hip is not dislocated at rest, but can be provoked to subluxate or dislocate), subluxed (the femoral head has moved or displaced from its normal position within the acetabulum), dislocated (no contact is made between the articular surface of the femoral head and the socket), or be stable but have acetabular dysplasia (malformed, immature or shallow socket).
What causes Hip Dysplasia?
In many cases, we do not know what causes hip dysplasia. Risk factors for hip dysplasia include breech presentation in utero, female sex, incorrect lower-extremity position in utero and family history of the condition. Overall, breech presentation and family history are thought to be the two most important risk factors when screening for hip dysplasia. A first degree relative (parent, sibling or child) increases the risk even higher. Left-side dysplasia is more common that right-sided dysplasia which may be due to in utero position.
What are the symptoms of Hip Dysplasia?
Infants typically do not have pain but may have a hip click or clunk, asymmetric or uneven gluteal (buttock) or anterior thigh folds and groin creases. Children who present later as toddlers or young children after they have begun walking can also be without symptoms or may have a painless limp. Sometimes, children may have vague complaints of activity related discomfort or hip pain, an asymmetric gait, limp or leg length differences.
How is Hip Dysplasia diagnosed?
Clinical examination along with radiographic imaging can help to determine a diagnosis. Asymmetry in hip range of motion and hip clunks may indicate dysplasia. Hip ultrasounds are done in infants starting at 6 weeks up to 6 months if there are any risk factors or feelings of hip instability. X-rays are often needed when an infant is over 6 months of age after the acetabulum and femoral head (hip ball and socket) has matured. Advanced imaging such as arthrography, MRI or a CT scan may be necessary.
How is Hip Dysplasia treated?
The main treatment for infants less than 6 months old is the Pavlik Harness. The harness is a nonsurgical treatment which allows for motion while treating the located hip. Another nonsurgical option is the Hip Abduction Orthosis (or brace). This is sometimes used if the Pavlik Harness does not stabilize the hip. Treatment is generally used either full or most of the time for a few months. Repeating clinical examinations and ultrasounds monitor the progress. The harness or brace maintains the hip in the correct position for stability. Surgical treatment options begin if there is no improvement after wearing the harness or brace.
Specific surgery is determined after a comprehensive evaluation and considers the age at presentation, the severity, the presence of the condition and the likelihood of success.
- In younger patients, closed reduction of the hip is the least invasive. This is a formal manipulation of the hip under anesthesia to get the hip lined up correctly within the socket, with immobilization in a hip spica body cast. A tendon in the groin may need to be cut or lengthened to improve the range of motion. This is typically done in infants less than one year.
- Open reduction of the hip is when the hip capsule is opened with an incision in the groin or an incision in front of the hip. After the tissues blocking reduction are removed, the hip is reduced (put back in the socket), and then the hip is immobilized in a spica body cast. If the initial procedure was a closed reduction which failed to stabilize the hip, the surgeon will often consider an open reduction in the operating room. Typically done in children 12-24 months.
- Open reduction of the hip with pelvic and/or femoral osteotomy. Open reduction (see above) of the hip followed by a pelvis and/or femoral osteotomy(cutting of bone) is sometimes required due to acetabular dysplasia (misshapen socket) or to redirect the femur. A cut may be necessary through the pelvis to achieve reorientation of the socket or the femur is cut to help direct the femoral head toward the center of the acetabulum. Keeping the child immobile will be necessary with a hip spica body cast. Typically, this approach is considered for children older than 18 months of age.
- Pelvic osteotomy may be used in an older child whose hip is not dislocated, but the shape or size of the acetabulum (socket) is insufficient. This cut in the bone around the socket can help reshape or reposition the socket to better support the joint. Recovery and casting/bracing after these procedures depends on the patient age and specific characteristics of the patient’s surgery
What is recovery like after surgery?
If the child was immobilized in a hip spica cast, it is used for anywhere from 6 to 12 weeks. Imaging will be done with the cast on.
Management in the hospitalized patient includes stabilization from anesthesia, care and comfort, pain control, safe feeding and care giver education. The surgeon, nurse, case manager (if necessary) and a social worker (if necessary) can be involved in the discharge process. Caregiver discharge teaching includes: pain medication management, cast or splint care, appropriate bowel regimen, safe handling, skin care, incision site assessment, dressing care, gait training using equipment with a physical therapist, signs and symptoms of infection and other potential complications or issues associated with anesthesia and circumstances in which to call the orthopedic team. Another consideration before discharge is appropriate equipment (car seat, safety belt, wheelchair, walker) and transportation concerns. Anticipatory guidance for age appropriate activities during the immobilization period is discussed. Educational age appropriate activities need to be employed during the healing phase. The child life specialist can be available to meet with patients and families to provide suggestions. School age patients can receive homebound instruction until it is safe for the student to go back to school depending on the school’s accommodations. Clear information regarding the post-operative appointment should be scheduled and discussed.
What are the outcomes after surgery?
The biggest immediate risk after surgery is that the hip does not stay in place. This would require additional procedures. There is a low risk for infection after surgery. Pain will be treated initially with a combination of epidural and intravenous pain meds followed by pain medicine by mouth. Other complications include a disturbance of the blood supply of the femoral head, also known as avascular necrosis (AVN) which can affect the quality of the hip development. More invasive procedures increase the risk of complications. The child will be monitored for many years to monitor for the patient’s overall developmental skills, function and watch hip development. Sometimes, additional surgeries are necessary (even if the hip stays in place) to assist the development. X-rays are required over time to monitor the hip. The goal is for a hip that will last as long as possible. In some cases, children with hip dysplasia may still need a hip replacement as an adult, but the goal of early treatment is to delay this into late adulthood instead of being needed at a young age.
The Division of Orthopaedic Surgery and Sports Medicine at Lurie Children’s has well-known expertise in the diagnosis and treatment in hip disorders. You may schedule an appointment with us to discuss even the most complex hip problems. Lurie Children’s Division of Orthopaedic Surgery and Sports Medicine, Department of Nursing, Pain Management, Physical Therapy, Radiology and Anesthesia work closely together as a team.
Our goal is to provide treatment programs that relieve symptoms and strive to keep the hip working well. We provide direct patient care and are also active in teaching and research for hip related disorders.
Call 1.800.KIDS.DOC for an appointment to receive more information on hip dysplasia.