A radiological study of the patella and the cartilage of patella by computed tomography following double-contrast arthrography

Recurrent subluxation or dislocation of the patella is a painful condition that frequently leads to chondromalacia or arthrosis of the patellofemoral joint. A radiographic evaluation of the patella and patella cartilage is important in the diagnosis of chondromalacia and mal alignment. Authors performed the patellofemoral joint CT following the double contrast arthrography in 53 patients with knee joint pains who had visited to Capital Armed Forces General Hospital from July to December, 1986. Authors analysed the shape and position of patella and the shape of patella cartilage. The results were as follows; 1. shape of patella:The most common types are type II/III (14 cases) and type III (14 cases). type III → IV-9 cases, type I-5 cases, type IV-5 cases, other type-4 cases, type II-2 cases, no type V. 2. position of patella:Only 2 cases showed subluxation and external rotation of patella. 3. shape of patella cartilage:a)congruous cartilage-21 cases (39.6%) b)regular cartilage-22 cases (41.5%) c)irregular cartilage-10 cases (18.9%) irregular imbibition of contrast media-7 cases localized loss of cartilage or erosion-2 cases thinning of cartilage-1 case 4. Fissure and erosions of cartilages in 3 cases were confirmed by operation and knee arthroscopy