Active Monitoring versus an Abduction Device for treatment of Infants with Centered Dysplastic Hips, a Comprehensive Cohort Study (TReatment with Active Monitoring (TRAM)-Trial)

The diagnosis Developmental Dysplasia of the Hip (DDH) is used for a wide
spectrum of growth disorders of neonatal and infant hips. The incidence of
dysplastic hip joints in The Netherlands is 1-4% of the infants up to 6 months
of age. Of these infants, the vast majority concerns stable, centered hips.
Only 10% of all DDH patients have instable or dislocated hips.
Residual dysplasia can lead to deterioration of the hip joint causing chronic
pain, degenerative hip disease and gait abnormalities later in life. Over
treatment of patients with normalizing hips during growth is a burden for
children, parents, and society and has a risk of introducing unnecessary
complications.
Diagnosis and classification of DDH is done by ultrasound using the Graf
method. Type 2 hips are stable but dysplastic. Type 3 and 4 hips are unstable
or dislocated.
Current treatment of all types of DDH uses a dynamic abduction device (Pavlik
harness). Treatment consists of centering the hip in the acetabulum and
subsequently gaining pressure in the deepest part of the acetabulum in order to
develop a sufficient bony and cartilaginous roof [6]. In dislocated hips this
treatment is proven effective in multiple studies. However, evidence for
treating centered, dysplastic hips (Graf type 2) is lacking. Natural history
seems more favorable for these hips compared to treatment since the vast
majority of centered hips tend to normalize during growth. Treatment does
expose the infants to the risks of abduction treatment, mainly avascular
necrosis (AVN) of the femoral head in 2-11% of the patients and (transient)
femoral nerve palsy in 2.5% of the cases. Furthermore, treatment of infants of
3 months old often induces stress and dilemma*s in families. Daily activities,
such as diaper changing, cleaning and carrying are more complex and the impact
of abduction treatment at this age is a burden for the whole family. In
addition, reducing unnecessary medical treatment will be cost-saving for
society as a whole. Therefore, active monitoring might be a useful alternative
in these infants with centered dysplastic hips. Active monitoring consists of
ultrasound and physical examination in order to receive appropriate treatment
if the hip deteriorates into a decentered hip.

The aim of this study is to compare treatment with an abduction device to
active monitoring of infants with centered dysplastic hips (Graf type IIa- or
IIb or IIc) during the first year of life.

The present study compares the costs and effectiveness of two treatment options
for infants with a stable, centered dysplastic hip, namely active monitoring or
the use of a dynamic abduction device, following a comprehensive cohort design
(CCD). The study is an open label study since blinding is not possible for the
patients/parents as well as for the treating physician. All patients will be
included after diagnosis at the outpatient clinic of the orthopedic department.

The CCD consists of a randomized controlled trial (RCT) and a parallel
prospective cohort, each with two arms (abduction treatment and active
monitoring; Figure 1). Primarily, parents/caregivers are asked to participate
in the RCT. In the prospective cohort, infants are included whose
parents/caregivers do not want their infant to be randomized to one of the
RCT*s treatment arms (i.e., who prefer either the abduction treatment or active
monitoring), but who are willing to participate in the study.

Treatment group assignment will take place at patient level. In case of
randomization, stratification for type IIa-/IIb/IIc DDH and for center will be
applied. In the parallel prospective cohort, parent/caregiver preference
decides treatment group assignment.

Patients will be followed for 24 months.

use of the Pavlik harness (abduction treatment)

Research suggests that active monitoring might be a good alternative for the
treatment of patients with centered dysplastic hips. Patients will be monitored
frequently and actively, in order to treat the hip in case of deterioration.
Therefore, the risks of this study are comparable to the risks involved with
standard treatment. No extra visits compared to regular care are necessary. For
the infants there will be no extra burden compared to regular care.