Abstract
Purpose
To determine (i) the relationship between osteonecrosis and hip function, physical function and quality of life in adolescents and young adults treated for DDH; and (ii) how affected children change over 10 years.
Methods
We included 109 patients (mean age 19.2 ± 3.8 years) with osteonecrosis and 30 age-matched patients without osteonecrosis following DDH treatment between 1992–2005. All completed valid patient-reported outcome measures to quantify their hip function (maximum score 100); physical function (maximum score 100); and quality of life (maximum score 1). Of these, 39 patients had been followed prospectively since 2006, allowing quantification of within-person changes over time.
We graded all radiographs for severity of osteonecrosis, residual dysplasia, subluxation and osteoarthritis. We determined the association between patient-reported outcomes and radiographic severity of osteonecrosis using mixed-effects regression analysis; and repeated-measures analysis of variance to quantify person changes over time. We adjusted for age, prior operations and acetabular dysplasia.
Results
In 135 patients (168 hips) with and without osteonecrosis, mean differences (95% confidence interval) in hip function, physical function and quality of life were 0.75 (−6.67, 8.17), −1.97 (−17.58, 13.60) and −0.05 (−0.91, 0.36), respectively. Adjusted analysis showed no difference in these outcomes based on radiographic severity of osteonecrosis (p> 0.05). Of 39 patients followed over 10 years, 4 had undergone hip arthroplasty. For the remainder, mean changes (95% confidence interval) in hip function, physical function and quality of life from baseline to current assessment were 7.18 (−2.11, 12.26), −2.11 (−15.47, 11.25), −0.03 (−0.11, 0.05), respectively. Radiographic severity of osteonecrosis was not correlated with changes in patient-reported outcomes over time.
Conclusion
Osteonecrosis secondary to DDH remains relatively benign even in young adulthood. Overall, patients demonstrated good hip function, physical function and normal quality of life. Equally, children maintained such high levels over the course of 10 years if their hip survived.
