Exploring a Manual Intervention on the Coxal Bone in Infants With Congenital Hip Dysplasia: A Pilot Study

This is an exploratory randomized pilot study with two parallel groups and baseline and post-intervention assessment of the primary outcome. Thirty infants are planned, with 15 participants per group. Allocation will use stratified randomization by sex and age with variable block sizes. The randomization sequence will be generated before recruitment by an independent person who is not involved in delivering the manual intervention. At T0, all infants will undergo the standard ultrasound assessment used in their orthopedic follow-up, together with collection of baseline clinical and demographic information. Infants assigned to the experimental group will receive the manual intervention in addition to conventional orthopedic treatment, once weekly for three consecutive weeks. Infants assigned to the comparison group will receive conventional orthopedic treatment alone. Adherence to Pavlik harness treatment will be documented in both groups. A final ultrasound assessment will be performed at T1 using the same clinical approach as at T0. For unilateral DDH, the dysplastic hip will be evaluated. For bilateral DDH, both dysplastic hips will be evaluated at T0 and T1 and recorded separately. The manual intervention will be delivered in a standardized manner by one osteopath who is also a physiotherapist and has 25 years of clinical experience, primarily with infants. With the infant in the supine position, manual contacts are placed on the ilium, pubis, and ischium. A gentle, progressive, convergent mechanical stress is directed toward the acetabular cavity. The mechanical stress is maintained for 1 minute and repeated 15 times with 30-second intervals. The session will be stopped immediately if the infant shows significant discomfort, distress, or intolerance. The primary outcome is the change in ultrasound-measured femoral head coverage from T0 to T1. Parental acceptability will be assessed using a study questionnaire informed by the Theoretical Framework of Acceptability and 5-point Likert-scale items. Feasibility measures will include recruitment, completion of intervention sessions, adherence to conventional orthopedic treatment, and tolerability.