[Why does the patellofemoral cartilage collapse? : A critical analysis of epidemiology, etiology and prevention]

Cartilage damage in the patellofemoral joint is common and often leads to pain-related restrictions in the patients' subjective activity level. The cause is often multifactorial.

The most common causes comprise chronic overuse, acute impact trauma, post-traumatic conditions or patellar fractures, while patellar instability with its anatomical risk factors (trochlear dysplasia, patella alta, lateralized tuberosity, genu valgum or torsional deformities) plays a key role. Acute cartilage damage or (osteo-)chondral fractures usually occur in the context of acute patellar dislocation or direct impact trauma. In this regard, early surgical refixation or resection of the (osteo-)chondral fragments is important and can contribute to a delay of further cartilage deterioration. Chronic cartilage damage usually results from a disorder of the patellofemoral kinematics, such as patellar maltracking. (Post-)traumatic conditions such as patellar fractures represent a special entity. Long-term cartilage deterioration and osteoarthritis can also emerge or progress by inadequate surgical procedures.

Therapeutically, the main focus should always be on correcting biomechanical imbalances, in order to allow for effective cartilage regeneration. The latter can be achieved by several techniques for cartilage regeneration.