Reoperations as an Outcome Indicator for Developmental Dysplasia of the Hip Treated at Walking Age.

Background: Reoperation is a major adverse event following surgical treatment but has yet to be used as a primary outcome measure in population studies to assess current treatments for developmental dysplasia of the hip (DDH). The purpose of the present study was to explore the risk factors associated with reoperations following procedures under anesthesia ("operations") for DDH in patients between the ages of 1 and 3.00 years, with the goal of deriving treatment recommendations.

Methods: This retrospective birth cohort study included children who had undergone closed reduction, open reduction, or osteotomy for the treatment of unilateral DDH between the ages of 1 and 3.00 years, identified using the Taiwan National Health Insurance Research Database. The children were followed until 10 years of age for reoperations, excluding implant removal and sequential closed reduction within 3 months postoperatively. A comparison between patients with and without reoperations was conducted, and binary logistic regression was used to identify factors associated with reoperation. Patients were further stratified by age and procedure for developing treatment recommendations.

Results: Among 2,261,455 live births from 2000 to 2009, 701 patients underwent operations for unilateral DDH between 1 and 3.00 years of age (an incidence of 31.0 per 1,000 live births). The initial operations included closed reduction (n = 86; mean age, 1.34 years), open reduction (n = 73; mean age, 1.53 years), pelvic osteotomy (n = 405; mean age, 1.59 years), femoral osteotomy (n = 93; mean age, 1.76 years), and pelvic osteotomy plus femoral osteotomy (n = 44; mean age, 1.84 years). Reoperations were performed in 91 patients (13%) at a mean age of 3.80 years. Comparison between patients with and without reoperations revealed the operative procedure as a significant factor. Logistic regression revealed that closed reduction was associated with a 1.8 to 9.0 times higher reoperation risk than open reduction, depending on age, whereas pelvic osteotomy was associated with 0.34 times the risk of reoperation than open reduction in patients 1.5 to 2.0 years of age.

Conclusions: Reoperations may not be directly linked to radiographic and functional outcomes but are important from the patient's perspective and in terms of cost-effectiveness. To reduce the risk of reoperation, the findings of the present study support open reduction to properly reduce the hip joint at walking age and additional pelvic osteotomy for patients beyond 1.5 years of age.

Level Of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.