There is irregularity and fragmentation of the distal femoral epiphysis.
This case represents a normal anatomical variation, where the distal femoral epiphysis appears irregular and fragmented, and should not be confused with any other pathology such as osteomyelitis or neoplasm.
In a study that was done in Seoul national university, an epiphyseal cortical irregularity occurred only in 105 out of 1,562 patients. A cortical irregularity was observed in patients under 4 years of age and ours at an earlier age in girls than in boys.
These findings disappear on follow-up radiographs as the patients are going older. An epiphyseal cortical irregularity is thought to be an incidental finding which needs no further evaluation and treatment. Some infants may show also fragmentation at the edge of the metaphyses. This finding is considered as a normal variation.
Reference
Seo SG, Sung KH, Chung CY, Lee KM, Lee SY, Choi Y, Kim TG, Baek JK, Kwon SS, Kwon DG, Choi IH, Cho TJ, Yoo WJ, Park MS. Incidental findings on knee radiographs in children and adolescents. (2014) Clinics in orthopedic surgery. 6 (3): 305-11.