Spastic Hip Dislocation - Clinical Tree

Introduction

Cerebral palsy is the most common neuromuscular disorder cared for by orthopedic surgeons. It has an incidence of 2 to 3 per 1000 live births, which has not changed dramatically in the last 50 years. The cerebral palsies are a group of disorders caused by an insult to the developing brain in the prenatal and postnatal period until the age of 2 years. Causes include premature birth, vascular insults, chromosomal abnormalities, genetic influences on the child and mother, metabolic causes, hemostatic causes, infectious causes, and trauma (birth and nonaccidental trauma). There is a broad range of involvement, ranging from children with mild balance issues to those with total body involvement requiring comprehensive care. The Gross Motor Function Classification System (GMFCS) is a classification system based on the ambulatory status of the patient. Levels I to III are ambulatory, whereas levels IV and V are nonambulatory. This system enables healthcare providers to predict the natural history of the level of involvement and determine the appropriate treatment. For example, performing surgery to allow a child with GMFCS level V to walk would be counterproductive. Although spasticity is a hallmark of cerebral palsy, most patients with GMFCS IV and V have a mixed type of cerebral palsy, with dystonia being the primary movement disorder. There are also patients, often with a chromosomal abnormality, who have hypotonia and hip subluxation/dislocation.

Most hip problems in cerebral palsy are present in GMFCS IV and V patients. However, there can still be hip problems in GMFCS II and III patients, although the development of hip subluxation or dislocation is rare in this group of patients. The exception might be the type IV hemiplegic patient who has involvement of the ankle (equinus), knee (flexion), and hip (increased anteversion, and potentially subluxation).

The development of hip subluxation and dislocation is usually a prolonged course of overactivity of the hip adductors and flexors relative to the abductors and extensors. The hip begins subluxating and can eventually lead to dislocation if untreated. Initially, there will not be any pain associated with this process, but as the child ages and there is a further deformity, there may be cartilage loss at the femoral head and the acetabulum leading to osteoarthritis.

Patient Selection

History

It is essential to obtain a complete patient history, including birth history, other medical problems, past medical and surgical interventions, and even family history. This will enable the surgeon to anticipate potential complications in the treatment period. A history of seizures, pulmonary problems (such as aspiration pneumonia or need for breathing assistance and oxygen), heart abnormalities, bleeding abnormalities, reflux, kidney stones, skin ulcerations, and even oral hygiene status should be known before surgery. It is necessary to have a team approach to the preoperative management of children with cerebral palsy. The concept of “clearance” for surgery is controversial. Still, preoperative consults with the child’s pediatrician and subspecialists will at least alert the team of potential problems that may arise during the perioperative period. Medication doses may be altered, and recommendations for other perioperative medications, such as desmopressin (DDAVP) for patients with diabetes insipidus, for example, will be critical in preventing complications.

Patient Considerations

Many patients will have poor nutrition, especially children with GMFCS IV and V cerebral palsy. Due to reflux, oromotor dysfunction, decreased or increased gastrointestinal transit time (diarrhea or constipation, respectively), abdominal pain from distention, and so on, malnutrition is a common problem in children with cerebral palsy. Not addressing this preoperatively can lead to wound-healing problems, ulcer formation, delayed healing of osteotomies, and even further weight loss. On the opposite end of the spectrum are those children who are obese secondary to overfeeding. Complications in this group include the need for larger incisions, potentially leading to increase blood loss and wound-healing problems.

There are many causes of osteopenia in children with cerebral palsy, including lack of weight bearing, poor nutrition, low calcium intake, and antiseizure medications. Many of these patients do not get outdoors and do not have adequate vitamin D levels, leading to rickets. Premature children also have lower levels of bone mineral content at birth. Osteopenia contributes to complications such as postoperative fractures, loss of implant fixation, and delayed healing. Osteopenia is challenging to treat, and treatment with vitamin D, calcium, and even bisphosphonates to improve bone quality before surgery is controversial.

A careful inventory of the patient’s medications is critical before surgery. Antiseizure medications can lead to osteopenia and liver abnormalities, valproate can lead to increased blood loss via platelet dysfunction, and many patients are taking over-the-counter supplements, which can lead to drug-drug interactions. In some cases, the primary care physician or subspecialist will change the medication dosage in the perioperative period to decrease these complications.

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here