Chondromalacia patella is divided into four stages based on the degree of damage or softening of the kneecap cartilage. These stages are:

Stage 1: Characterized by the softening of the cartilage under the kneecap. This indicates an early stage of chondromalacia.
Stage 2: In addition to cartilage softening, irregularities and fissures begin to form on the cartilage surface. This indicates a progression of the condition.
Stage 3: Significant thinning, deterioration, and fragmentation of the cartilage structure are observed.
Stage 4: This is the most advanced stage, where a large portion of the cartilage is severely damaged or lost, exposing the underlying bone tissue. In this condition, bone surfaces directly rub against each other during knee movements.