Approach

The natural history of many stable, radiologically dysplastic hips is likely one of spontaneous improvement and, therefore, there is some controversy regarding which abnormal hips require treatment.[26][27] Nevertheless, it is important to identify children who need treatment to improve their expected outcome. Treatment is dependent, primarily, upon age at presentation, if the dislocation is congenital or not, and severity of hip instability and dysplasia. Teratologic dislocated hips include those that are fixed prenatally.

Generally, early diagnosis and initiation of treatment will result in a high rate of successful outcome with less invasive interventions and low incidence of complications.[28][29][30][31][32][33][34] Infants and children with hip instability or a suspected hip abnormality (including subluxation) on clinical exam should be referred to a pediatric orthopedic surgeon for clinical, sonographic, and/or radiologic monitoring and treatment if indicated.

The goals of treatment are to:

  • Obtain and maintain a stable, concentric reduction of the hip

  • Optimize functional and anatomic results

  • Avoid complications.

Infants <6 months

Hip dysplasia

  • For infants <2 months of age with mild dysplasia without instability on ultrasound and normal exam, a repeat ultrasound can be obtained in 3 weeks. If the ultrasound remains abnormal at 6 weeks of age, treatment with a Pavlik harness is typically recommended to enhance optimum hip development.[10][35]​ Serial follow-up is warranted with ultrasound and plain x-ray evaluation at 6 months of age.​​

  • If dysplasia persists or worsens, a rigid abduction brace may be used and has been successful in over 80% of cases that fail a Pavlik harness.​​[36][37][38]​​​

  • Less than optimum radiographic findings warrants further evaluation and treatment, which might include exam under anesthesia, arthrogram, and spica casting.[39]

Hip subluxation

  • For neonates with hip subluxation, observation without treatment intervention is recommended for up to 3 weeks because most will experience spontaneous resolution.[28][40] Although using triple diapering is unlikely to be detrimental to the infant or to its hip development, it has not been shown to provide any added benefit in obtaining hip stability within the first 3 weeks.[28]

  • After 3 weeks, those with persistent subluxation warrant treatment for a dislocated hip.

Nonteratologic hip dislocation

  • A hip abduction orthosis (splint), such as the commonly used Pavlik harness, can achieve closed reduction of a dislocated hip more than 90% of the time.[28][41]​ Frequent routine clinical follow-up is required over a period of at least 3 months to minimize potential complications and ensure stability and development. For example, osteonecrosis and nerve palsy may occur secondary to suboptimal positioning within the brace, forced abduction, and/or excessive flexion. Reported rates of osteonecrosis with Pavlik harness use vary from 0% to more than 7%.[28][41]​ Higher rates of osteonecrosis seem to be associated with more extreme positioning to achieve reduction in severe or difficult cases.[28]

  • If stable reduction of the hip has not been achieved after 3-4 weeks of harness use, the harness must be discontinued to prevent worsening posterolateral acetabular erosion and dysplasia, the phenomenon of Pavlik harness disease.[32][42]​ A more rigid hip abduction splint may be considered, and it can be successful in up to 80% of cases that fail treatment with a Pavlik harness.[36][37][38]

  • Children who have failed treatment with harness or brace need a formal closed reduction under general anesthesia with arthrographic confirmation and placement of a spica cast (a cast that includes the trunk of the body and one or more limbs).[43]

  • In children who have experienced a failed closed reduction attempt, open reduction surgery with a spica cast is recommended.[31][37]

Teratologic hip dislocation

  • Refers to fixed dislocation of the hip that occurs prenatally. An open reduction surgery with a spica cast is recommended.

AAOS: appropriate use criteria: developmental dysplasia of the hip Opens in new window

Children 6 to 18 months of age

Nonteratologic hip dislocation

  • Closed reduction under general anesthesia with arthrographic confirmation and placement of a spica cast is the recommended treatment for hip dislocation in most children ages 6-18 months.

  • For children in whom attempts at closed reduction have failed, open reduction may be required.[31][37]

Teratologic hip dislocation

  • An open reduction surgery with a spica cast is recommended.

Children >18 months to 6 years of age

Open reduction surgery with a spica cast is recommended for children with both teratologically dislocated hips and those that are not teratologically dislocated. A pelvic osteotomy may be considered at the time of open reduction.

Children >6 years of age

In children >6 years of age, there is little potential for remodeling. Cases of acetabular dysplasia or subluxation are often treated with hip reconstruction, which consists of pelvic and/or femoral osteotomies and sometimes may necessitate an open reduction. Salvage pelvic osteotomies may be considered in cases where a concentric reduction cannot be achieved. In patients >6 years of age with bilateral dislocations or patients >8 years of age with unilateral dislocation, observation could be considered. However, there is limited research and decisions should be made on a case-by-case basis and in a shared manner with the family.

Closed reduction with spica casting

The procedure involves the injection of dye into the joint to outline cartilage of the femoral head to assess reduction.

Adductor tenotomy is frequently performed to decrease adduction contracture and allow increased abduction and femoral head stability before application of spica cast immobilization. This step increases the “safe zone.”

Cast immobilization is typically continued for 12 weeks or until hip stability has been achieved. Transition from the cast to a splint is commonly practiced thereafter, with discontinuation at the discretion of the orthopedist when it is believed that stability will be maintained unbraced.

Once closed reduction of a hip dislocation is obtained, continued serial radiographic monitoring is required to monitor possible residual dysplasia, recurrent instability, and osteonecrosis.

Open reduction with spica casting

The procedure permits the removal of intra-articular obstacles, concentric reduction, and capsulorrhaphy, which will stabilize the joint.[44]​ Cast immobilization depends on the type of open reduction (anterior or medial) and should be continued until hip stability has been achieved.

Transition from the cast to a splint is commonly practiced thereafter, with discontinuation at the discretion of the orthopedist when it is believed that stability will be maintained unbraced.

The more challenging surgery in the older child runs the risk of converting an asymptomatic dislocated hip into a symptomatic dysplastic hip. Therefore, the upper age limit for open reduction of asymptomatic, bilateral hip dislocations is about 6 years.[45][46][47]

In older children, femoral shortening or derotation osteotomy may be performed at the time of an open reduction to enhance ease of reduction and to help minimize the risk of osteonecrosis by decompressing the soft tissues about the hip.[48][49]​ Pelvic osteotomy may be required to address instability, inadequacy of femoral head coverage, or residual acetabular dysplasia in patients >18 months of age.

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