Pediatric orthopaedic cases 23

CASE                               23                               

 

A 2-week-old girl, born to a G1P1 mother, is brought to you for evaluation due to concern for “hip click.” On examination, she has full range of motion of the hips. She is Ortolani negative on examination bilaterally, but you do note a positive Barlow on one side. The rest of her examination is unremarkable.

What is the next step in treatment?

  1. Pavlik harness

  2. Closed reduction

  3. Observation

  4. Open reduction

  5. Double diaper

 

Discussion

The correct answer is (C). Hip clicks are nonspecific physical findings and can be seen in children with normal hips. This child is only 2 weeks old. The hips are reduced on examination (Ortolani negative). Eighty percent of hips with evidence of dysplasia or that can subluxate/dislocate with a Barlow maneuver resolve in the first 6 weeks. Therefore, for this patient you would observe and reassess at age 6 weeks with a physical examination and ultrasound if there are risk factors or positive findings on examination. If the hips are dysplastic at that time, then you would initiate Pavlik harness treatment. A closed or open reduction is incorrect because the hips are not dislocated. Double diapering is not effective for treatment of hip dysplasia.

If the mother had a history of DDH and another daughter with DDH, what is the likelihood the second daughter will have DDH?

  1. Not related

  2. 6%

  3. 12%

  4. 36%

 

Discussion

The correct answer is (D). DDH etiology is multifactorial with a genetic component.

Family history is important to obtain. With a parent and a sibling with DDH, the likelihood that the child will have DDH is 36%. With just a parent the likelihood is 12% and if just a sibling it is 6%.

At 6 weeks, the ultrasound demonstrates an alpha angle of 40 degrees with <50% of the femoral head covered on one side, the other hip is normal. She is treated in a Pavlik harness.

What are the risks associated with Pavlik harness?

  1. Inferior head dislocation

  2. Femoral nerve palsy

  3. Osteonecrosis

  4. All of the above

 

Discussion

The correct answer is (D). Inferior head dislocation is associated with flexing the hips >90 degrees. Femoral nerve palsy is usually in older infants with increased hip flexion. The harness is stopped until the nerve palsy recovers. Osteonecrosis is from forced abduction and traction on the hip for reduction. All are potential risks that the family needs to be educated about, and the harness position needs to be monitored and adjusted to minimize these risks.

Another patient returns to your clinic for follow-up. She is a 3 month old you met a few weeks ago, and she was found to have an Ortolani positive hip on examination for which you started Pavlik harness treatment to try to reduce and hold the hip. On examination today, you note that the hip is dislocated and no longer reducible.

What is your next step in treatment?

  1. 2 more weeks of Pavlik harness

  2. Closed reduction in clinic

  3. Closed reduction in OR

  4. Open reduction

 

Discussion

The correct answer is (C). The baby is placed under anesthesia to allow the muscles to relax, and the hip can often then be reduced. An adductor tenotomy is usually performed to help prevent dislocation as it widens the safe zone. An arthrogram is performed to ensure a concentric, well-seated reduction. The angle between the

maximum abduction and minimum abduction in which the hip remains reduced, is determined and referred to as the safe zone. A spica cast is placed with the hip maintained between about 90 and 100 degrees of flexion and less than 60 degrees of abduction to reduce the risk of osteonecrosis. An MRI or CT is done after spica cast placement to determine if the hip remains reduced once the spica cast is on. If the hip is reduced in the cast, casting is continued for 3 to 4 months (with a spica cast change at the mid-point) and then the child is continued in an abduction brace until the dysplasia has fully resolved.

In the next patient room, you meet a 20-month-old girl who, since she started walking at age 14 months, has had “an odd-gait” per her parents. They recently took her to their new pediatrician for this concern. The pediatrician agreed with them and also noticed that one hip did not abduct as much as the other. The pediatrician ordered an AP pelvis x-ray and referred them to you for evaluation. On the x-ray, you note that one hip is dislocated, and there is a pseudoacetabulum forming. You speak to the family about the need for an open hip reduction.

Which of the following is not included as a part of an open hip reduction (at any age)?

  1. Traction

  2. Femoral shortening osteotomy

  3. Lengthening of adductors

  4. Abductor release

 

Discussion

The correct answer is (D). Gentle traction is used to assess reduction. Femoral shortening osteotomy is performed when the hip is really high-riding and too much force is required to reduce the hip—this is frequently necessary in children older than 2 years of age. The adductors are often lengthened or released. The iliopsoas, pulvinar, labrum, inferomedial capsule, ligamentum teres, and transverse acetabular ligament are often barriers to reduction that are addressed at the time of an open reduction. The abductors are not included in open hip reductions as they do not contribute to the dislocation or prevent reduction.

Your final patient of the morning is a 5-year old with a fixed dislocation of the left hip that was just adopted, and her new family has been trying to establish medical care for her. She was seen by a pediatrician recently and referred. She has a notable limp on examination and is Galeazzi positive on the right. She has limited hip abduction on the left compared to the right. You confirm the diagnosis of

unilateral hip dislocation on her x-rays.

 

What is the next step?

  1. Traction

  2. Closed reduction

  3. Open reduction

  4. Pelvic osteotomy

 

Discussion

The correct answer is (D). With a fixed unilateral dislocation under age 8, you would do an open reduction with a pelvic osteotomy to improve anterior and lateral coverage of the femoral head. A femoral shortening osteotomy may be needed in addition to the pelvic osteotomy. The other answers are not sufficient to reduce and stabilize a hip dislocation in a 5-year old.