Background: Up to 4% of all neonates in Central Europe are born with congenital hip dysplasia (CHD), the most common congenital disease of the musculoskeletal system. However, in this retrospective analysis the outcomes of infants with CHD (type D, III or IV according to Graf) have been considered, with Pavlik therapy starting within the first 12 weeks of life. Connections between the start of therapy or the first finding according to Graf`s classification and the ultrasound result achieved, as well as the X-rays taken after 1 and 2 years, were evaluated. No repositioning under Pavlik treatment or side effects and their relevance have been evaluated, especially with regard to avascular necrosis (AVN) of the femoral head.
Materials and methods: All infants treated using Pavlik treatment for CHD between 2010 and 2012 in our clinic were determined. A total of 62 patients with 79 pathological hips were included. The infants were classified into three groups to evaluate the influence of the start of therapy on the result: group I with the first investigation and start of treatment within the first 10 days of life, group II between the 11th day and the end of week 3, group III within preventive general examinations (U3) after the 4th week. Clinical examinations and the usual ultrasound scans were performed at an average of 1, 3, and 6 months. Furthermore, after 1 and 2 years clinical and radiological investigations were carried out, as well as further examinations depending on the findings.
Results: A failure of repositioning of the Pavlik treatment occurred in group I in 1 case (2.2%), in group II in 1 case (7.1%), and in group III in 2 cases (10%). This occurs in hips type D and type III in 1 case each (3.3%) and type IV in 2 cases (10.5%). Maturation disorders of the hips were found in 1 case (2.2%) in group I, 1 case (7.1%) in group II, and 3 cases (15%) in group III. Avascular necrosis of the femoral head was proven in 2 cases (4.4%) in group I, 0% in group II, and in 1 case (5%) in group III. All patients initially had femoral head necrosis of Graf type IV . All necrosis and maturation disorders were no longer visible on subsequent examinations after 2 years at the most.
Conclusions: In summary, the study shows that even with a late treatment start (U3) good results could be achieved, but with a rising number of repositioning failures and femoral necroses. Ultrasound screening on U3 seems to be sufficient; however, for high-risk groups an additional screening in the first week of life should be performed, which does not replace a second evaluation at U3 if there are normal findings.
Keywords: Femoral head necrosis; Hip dislocation; Neonatal screening; Retrospective studies; Ultrasonography.