Incidence of Hip Dysplasia Diagnosis in Young Patients With Hip Pain: A Geographic Population Cohort Analysis

BACKGROUND: Hip dysplasia is a common source of hip pain and a known cause of early osteoarthritis of the hip. PURPOSE: To (1) define the population-based incidence of hip dysplasia diagnosis in young patients presenting with hip pain in a large geographically defined cohort, (2) analyze trends regarding presentation and diagnosis of hip dysplasia, and (3) report the rate and type of surgical interventions used to treat this population. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A geographic epidemiological database was queried to identify patients aged 14 to 50 years with hip pain between the years 2000 and 2016. Patient medical records were analyzed, and demographic, imaging, clinical, and treatment history were recorded. Incidence trends were examined by use of linear regression with confidence intervals for age and calendar year. RESULTS: Overall, 1893 patients were included. Of these, 156 patients (196 hips) had a diagnosis of hip dysplasia. The incidence of hip dysplasia diagnosis in patients who reported hip pain was 12.7 per 100,000 person-years. Patients with dysplasia had a mean age of 26.7 ± 9.8 years, while the highest age-adjusted incidence occurred at age 14 to 18 years in both male and female patients. Female patients had double the age-adjusted incidence of male patients (cases per 100,000 person-years: 16.8 [95% CI, 13.9-19.7] vs 8.7 [95% CI, 6.6-10.8]; P < .01). Of the patients who underwent magnetic resonance imaging, 77% had imaging consistent with labral pathology. Patients were treated with physical therapy (67%), intra-articular steroid injection (29%), hip arthroscopy (10%), and periacetabular osteotomy (9%). The use of hip arthroscopy significantly increased over time (P < .01), whereas the use of steroid injection and periacetabular osteotomy did not (P < .28 and P < .08, respectively). CONCLUSION: The incidence of hip dysplasia diagnosis in patients presenting with hip pain was 12.7 per 100,000 person-years. Female patients had twice the age-adjusted incidence of male patients, and the highest age-adjusted incidence occurred in the age range of 14 to 18 years in both sexes. The use of hip arthroscopy to treat patients with hip dysplasia significantly increased over time.