From the Guidelines
Hip dysplasia is a developmental disorder where the hip joint forms abnormally, resulting in instability between the femoral head and acetabulum, and its treatment should prioritize early detection and intervention to prevent long-term complications like premature osteoarthritis, as emphasized by the most recent study 1.
Definition and Etiology
Hip dysplasia occurs due to genetic factors, hormonal influences (particularly maternal relaxin), positioning in utero (especially breech presentation), and environmental factors like tight swaddling. The pathophysiology of DDH is multifactorial and not completely understood, with the two leading causes being laxity induced by maternal hormones and limited in utero hip mobility 1.
Clinical Aspects
Clinically, infants may present with asymmetric skin folds, limited hip abduction, or leg length discrepancy, while adults typically experience pain, limping, and reduced mobility. The most important risk factors for DDH are female gender, breech positioning in utero, and a positive family history, carrying relative risks of 2.5,3.8, and 1.4, respectively, in a large meta-analysis 1.
Diagnosis
Early diagnosis is crucial and involves physical examination techniques like Ortolani and Barlow maneuvers in infants, along with imaging studies such as ultrasound (preferred for infants under 6 months) and X-rays for older children and adults. The American Academy of Pediatrics (AAP) recommends selective screening of children with risk factors or based on physical examination findings 1.
Treatment
Treatment varies by age and severity, with the Pavlik harness being the primary treatment for infants, worn for 6-12 weeks to guide proper hip development, as supported by the most recent and highest quality study 1. Older infants and children may require closed reduction under anesthesia followed by spica casting for 3-6 months. Severe cases or treatment failures may necessitate surgical intervention, including open reduction, femoral or pelvic osteotomies. In adults, treatment focuses on pain management with NSAIDs, physical therapy, and activity modification, with total hip replacement often needed for advanced cases. Early detection and treatment significantly improve outcomes by promoting normal hip development and preventing long-term complications like premature osteoarthritis, which explains why universal screening programs exist in many countries.
Some key points to consider in the treatment of hip dysplasia include:
- The goals of an ideal screening program are early detection of patients who have DDH when therapy is typically noninvasive and often most effective and exclusion of patients without DDH for whom unnecessary treatment could be costly and potentially harmful 1.
- The most serious complication of treatment is avascular necrosis, which is a predictor of poor prognosis 1.
- Universal US screening for DDH in newborns is performed in some European countries, but there is no evidence that it significantly decreases late diagnosis of DDH, and the higher rates of abduction splinting carry the risk of overtreatment and iatrogenic avascular necrosis 1.
From the Research
Definition and Etiology of Hip Dysplasia
- Hip dysplasia is a condition where the hip socket does not fully cover the ball portion of the upper thighbone, leading to an increased risk of arthritis and mobility problems 2.
- The etiology of hip dysplasia can be related to various factors, including genetic and neuromuscular causes, although these were excluded in the study by 2 to focus on surgical outcomes in adults.
Clinical Aspects of Hip Dysplasia
- Hip dysplasia can manifest with symptoms such as pain and limited mobility in the hip, especially in adults with advanced stages of the condition 2.
- The severity of hip dysplasia can be classified using the Tonnis grade, with higher grades indicating more severe arthritis, although patients with Tonnis grade 2 or greater arthritis were excluded from the study by 2.
Diagnosis of Hip Dysplasia
- Diagnosis of hip dysplasia typically involves a combination of physical examination, medical history, and imaging studies such as X-rays to assess the shape and alignment of the hip joint 2.
- The lateral center edge angle can be used to classify the severity of hip dysplasia, with angles between 18° and 25° considered borderline dysplastic 2.
Treatment of Hip Dysplasia
- Treatment options for hip dysplasia include hip arthroscopy, Bernese periacetabular osteotomy (PAO), and a combined approach of both procedures 2.
- Hip arthroscopy has been shown to result in improved outcomes in borderline dysplastic cases, while PAO has been primarily used in true dysplasia with continued success 2.
- The conversion rates to total hip arthroplasty (THA) varied among the treatment options, with rates of 4.8% for arthroscopy alone, 12.0% for PAO alone, and 17.7% for the combined approach 2.