PARALLAX RADIOLOGY OF THE HIP

We report our use of a simple radiographic technique that uses the pri nciple of parallax for evaluating the anterior-posterior relationship of the proximal femur to the triradiate cartilage in skeletally immatu re patients. Thirty-six paired plain radiograph parallax views were co mpared with 13 respective computed tomography scans of the hips in sev en patients. All had undergone closed or open reductions and were in s pica casts at the time of radiographic evaluation. The parallax views detected all cases of anterior or posterior subluxation or dislocation when present. We found this method to be reliable and easily performe d in the casted patient for use in radiographically evaluating pediatr ic hip subluxation in the anterior-posterior dimension.