Pelvic dysplasia, also known as developmental dysplasia of the hip (DDH), is a condition where the hip joint does not form correctly. The hip socket (acetabulum) fails to adequately cover the ball of the upper thigh bone (femoral head), leading to instability within the hip joint.
What is Pelvic Dysplasia?
Pelvic dysplasia encompasses a spectrum of hip joint abnormalities, from mild looseness to complete dislocation. In infants and children, it is known as Developmental Dysplasia of the Hip (DDH). The hip joint operates as a ball-and-socket mechanism, with the rounded top of the thigh bone (femoral head) fitting into a cup-shaped indentation in the pelvis (acetabulum).
With DDH, the acetabulum may be shallow, irregularly shaped, or misaligned, resulting in insufficient femoral head coverage. This can cause the femoral head to be loose within the socket, or to slip partially or completely out of place. The ligaments that help hold the joint together may also be stretched, further contributing to instability.
Recognizing Signs and Causes
Signs of pelvic dysplasia vary by age. In infants, caregivers may notice uneven leg lengths, asymmetrical skin folds on the thighs or buttocks, or a reduced range of motion in one hip. A “clunk” or “click” sound might be heard or felt when moving the hip. Babies may also be late in reaching developmental milestones like sitting or walking, and toddlers might develop a limp.
For older children and adults, symptoms include limping and hip pain, often worsening with activity and felt in the groin. Individuals may also experience hip looseness, a catching or popping sensation, or reduced range of motion. Mild dysplasia might not cause symptoms until adolescence or young adulthood.
Several factors contribute to pelvic dysplasia. Genetics are a factor, with increased risk if there is a family history of DDH. Being a first-born child can also increase the risk.
Female infants are more commonly affected than males. A baby’s position in the womb, such as breech presentation, can place extra stress on the hip joints. Certain swaddling practices that keep an infant’s hips extended and straight may also contribute to DDH after birth.
Identifying and Addressing Pelvic Dysplasia
Diagnosis of pelvic dysplasia involves physical examinations and imaging. For newborns and infants, doctors routinely check for DDH during well-child visits, performing specific maneuvers. The Ortolani test involves gently abducting the hip while applying upward pressure, which may produce a “clunk” if a dislocated hip reduces into the socket. The Barlow maneuver involves gently adducting the hip while applying backward pressure, which can cause an unstable hip to slip out of the socket. Asymmetrical skin folds, limited hip abduction, or differences in leg length may also indicate the condition.
Imaging Techniques
Imaging confirms diagnosis and assesses severity. For babies under six months, ultrasound is preferred because their hip joint is mostly soft cartilage, which is not visible on X-rays. Ultrasound provides a detailed view of the hip joint and surrounding soft tissues. For children over four to six months, when bones ossify, X-rays are effective for evaluating hip alignment and bony abnormalities. For more detailed images, MRI or CT scans may be used, especially in older children and adults.
Treatment Approaches
Treatment varies by age and severity. For infants under six months, non-surgical methods are the initial choice. The Pavlik harness is a common soft brace that gently holds the baby’s hips in a flexed and abducted position, allowing the femoral head to sit properly within the acetabulum and stimulate normal development. The harness is worn for several weeks or months, often full-time.
If the Pavlik harness is unsuccessful or if diagnosed at an older age (after six months), other interventions are considered. A closed reduction, performed under general anesthesia, involves manually guiding the femoral head back into the socket without incisions, followed by immobilization in a spica cast for several months. For older children and adults with severe or persistent dysplasia, surgical procedures may be necessary. An osteotomy, such as a periacetabular osteotomy (PAO), reshapes or reorients the hip socket or thigh bone to improve joint fit and stability. In cases of advanced hip deterioration in adults, a total hip replacement may be required to relieve pain and restore function.
Navigating Life with Pelvic Dysplasia
Early diagnosis and intervention significantly influence the long-term outlook for individuals with pelvic dysplasia. Untreated or severe cases can lead to secondary issues like early-onset osteoarthritis of the hip. This happens because abnormal hip joint alignment causes increased stress and wear on cartilage. Untreated dysplasia can also result in labral tears, tendinitis, bursitis, and muscle strains due to altered hip mechanics.
Ongoing management includes regular follow-up with orthopedic specialists. Physical therapy helps maintain hip function, strengthen surrounding muscles, and improve range of motion. Lifestyle adjustments, such as avoiding high-impact activities, may also be recommended to preserve joint health. Continued care and adherence to management strategies are beneficial for maintaining hip function and overall quality of life.