[Preliminary investigation on the pathogeny, diagnosis and treatment of chondromalacia patella]

This paper presents the preliminary investigation on chondromalacia patella at our department in recent years. A random cluster sampling survey covering 2743 normal persons was carried out. The prevalence rate is 36.2%. It was found that, applying transmission electron microscope and immunohistochemical methods on to cartilage tissues of the abnormal region, articular cartilage necrosis was in direct proportion with the abnormal pressure, while the restoration capability of local chondrocytes was in inverse proportion with pathological changes and the pressure. The chondromalacia patella was produced by repeated abnormal stress acting on the cartilage. The stress derived from the uncongruency and the decreasing in the contact area of patellofemoral joint when the subluxation or tilt of patellae was caused by the abnormal anatomical and biomechanical relationship. The initial lesion was at the matrix of cartilage, the collagen network was disrupted, then proteoglycan was lost. The microenvironment of chondrocytes was changed with degradation of matrix. So the chondrocytes became degenerative and necrosis from superficial to deep layer, then feed back the matrix again. Finally, the total cartilage layer might disappear, and the bone under cartilage might proliferate. At late stage, the cartilage was completely destroyed and had no self-restorative ability. Therefore, early diagnosis and treatment are necessary. It is highly suggested axis radiograph of the knee with the tibiae tuberositas localization are helpful to early diagnosis. Furthermore, JKY-Muscle Rehabilitation Instrument is invented for non-operative therapy. It enhances muscle power by selective training of the vastus medialis muscle using electrical stimulator to relieve pain and correct subluxation of patella with 90% efficiency (63% of excellent-effective rate). In late stage, patellofemoral replacement is recommended. The excellent-effective rate is 86.3%.