MAGNETIC-RESONANCE-IMAGING IN DIAGNOSTICS AND THERAPY CONTROL OF PATIENTS WITH CONGENITAL DYSPLASIA AND DISLOCATION OF THE DIP

Aim: In patients with congenital dislocation of the hip the assessment of the correct position of the hip joint after closed or open reducti on is very difficult to make from the radiograph with the hips in plas ter. As the delayed recognition of a recurrent hip dislocation has bad effects on the outcome of the affected hip a safe and reliable imagin g method must be employed. Method: From 1993 to 1996 6 patients with 8 congenital dislocations of the hip joint were examined by magnetic re sonance imaging for evaluation of the position of the hip in plaster a fter reduction. Magnetic resonance imaging was performed immediately a fter closed or open reduction. 3 hips had to be treated by open surger y. Results: The investigation confirmed that magnetic resonance imagin g allows perfect differentiation between the bony and cartilaginous pa rts of the hip joint in plaster as well. Interpositioning of soft tiss ues which prevent reduction could also be visualised clearly. The best , sequence in order to differentiate bony from cartilaginous structure s was a gradient echo sequence in flash-technique using a flip-angle o f 60 degrees. In all cases the correct position of the hip joint after reduction could be demonstrated in plaster. Conclusion: Therefore, ma gnetic resonance imaging is the imaging method of choice for confirmat ion and documentation of the reduced position of the hip joint in plas ter. Radiographs are no longer needed.