CT SCANNING OF THE PATELLOFEMORAL JOINT - THE QUADRICEPS RELAXED OR CONTRACTED

A study of the patellofemoral joint in patients with patellofemoral pa in has been carried out in 14 patients (18 knees) to compare CT scans with the knee extended fully and the quadriceps muscle contracted or r elaxed. The purpose was to decide whether both examinations are necess ary in young adults with suspected patellar malalignment. The patients were selected randomly. Thirteen knees were also examined in 20 degre es of flexion. The lateral patellar angle and the lateral patellar shi ft were measured. Linear regression analysis showed a proportional rel ationship between measurement with the quadriceps contracted and relax ed. Therefore, only one examination is needed and is easier to carry o ut in the relaxed state. Radiation to the patient and costs are reduce d.