Demographic and Diagnostic Characteristics of Patients Treated by Closed Reduction for Developmental Dysplasia of the Hip Under Four Months of Age

Schaeffer, EK., Matheny, T., Williams, N., Mulpuri, K. Demographic and Diagnostic Characteristics of Patients Treated by Closed Reduction for Developmental Dysplasia of the Hip Under Four Months of Age. Canadian Orthopaedic Association Meeting, Vancouver, BC, Canada. June 2025.

Abstract

Purpose:

Closed reduction (CR) is the most common surgical treatment for children with DDH from 6-18 months of age. Potential for increased complications has been noted in older children, but not much focus has been placed on children undergoing the procedure younger than six months. The purpose of this study was to determine the proportion of infants undergoing CR under four months of age in a global registry, and examine the demographic and diagnostic characteristics of this cohort.

Method:

A global, prospective registry of infants and children diagnosed with DDH was analyzed for patients undergoing CR, and the cohort of infants under four months of age was further examined. Demographic and diagnostic variables included age at diagnosis and surgery, sex, DDH risk factors, laterality, percent coverage of the femoral head and alpha angle. Categorical variables were summarized using frequencies and percentages, and continuous variables were summarized using means and standard deviations (SD).

Results:

We identified 532 instances of CR across 23 centres globally. Of those, 34 hips (28 patients, 71.4% female) underwent CR under four months of age across 10 centres (6.4% of all CRs). Cases in this age cohort represented no more than 14.8% of all CRs at any individual centre. Regarding risk factors, six patients (21.4%) were born breech, seven (25%) had a family history and 10 (35%) reported swaddling. Mean age was 1.49 months (SD 1.18) at diagnosis and 3.01 months (SD 0.84) at CR. There were 15 unilateral left, seven unilateral right and six bilateral cases; 23/34 hips (67.6%) were reducible on clinical exam. Mean percent coverage of the femoral head on ultrasound of operated hips was 16.5% (SD 20.3) and mean alpha angle was 42.9 degrees (SD 10.3). Six patients were initially monitored, and 15 were previously braced. Initial CR was successful in 32/34 hips (94.1%).

Conclusion:

While the cohort of patients less than four months undergoing CR is small (34 hips), the procedure was typically successful (94.1%). Cases were relatively evenly distributed across 10 centres, suggesting that performing CRs in this age group was not specifically due to specific surgeon or centre practice decision-making. This study demonstrates the relative rarity with which CR is performed in infants under four months of age, representing 6.4% of all CRs performed in a global cohort of infants and children diagnosed with DDH. Future work includes comparison to the older CR cohort, and long-term follow-up to examine radiographic and functional outcomes.