This image looks like a patellar fracture, but it is actually something called a 'bipartite patella' - where the embryonic components of the kneecap have failed to fuse properly as the person grew.
What is a bi-partite patella?
Found normally (without injury) in a small percentage of people, a true bi-partite patella usually has a larger part, comprising most of the patella, and a second smaller part connected to the other by strong fibrous tissue.
Very occasionally, a divided patella does occur as a result of injury when two pieces of a fractured (broken) patella fail to unite. This is correctly called a 'non-union' rather than a bi-partite patella.
Peer-reviewed papersQuote from peer-reviewed paper:
"...[Bi-partite patella is} a rare cause of anterior knee pain due to the failure of the secondary ossification centers of the patella to completely fuse during adolescence....[it] occurs in 2% of the population with equal prevalence in males compared to females....often an incidental, asymptomatic finding on radiographs...."
Citation: Pan T, Hennrikus W. Symptomatic Bipartite Patella in Adults Treated With Open Excision: Outcomes and Management. Cureus. 2022 Jul 9;14(7):e26705. doi: 10.7759/cureus.26705. PMID: 35959180; PMCID: PMC9359909.