"Male varanids have a cartilaginous or bony support structure in each hemipenis called a hemibaculum."
references:
Auffenberg, W. The Behavioral Ecology of the Komodo Monitor. Gainesville: University Press of Florida, 1981. ——. The Bengal Monitor. Gainesville: University Press of Florida, 1994. ——. Gray's Monitor Lizard. Gainesville: University Press of Florida, 1988.
Bennett, D. Monitor Lizards. Natural History, Biology and Husbandry. Frankfurt am Main: Edition Chimaira, 1998.
King, D., and B. Green. Goannas The Biology of Varanid Lizards. University of New South Wales Press, 1999.
Murphy, J. B., C. Ciofi, C. de la Panouse, and T. Walsh, eds. Komodo Dragons: Biology and Conservation. Washington, DC: Smithsonian Institution Press, 2002.
Pianka, E. R., and L. J. Vitt. Lizards: Windows to the Evolution of Diversity. Berkeley: University of California Press, 2003.
Zug, G. R., L. J. Vitt, and J. P. Caldwell. Herpetology: An Introductory Biology of Amphibians and Reptiles. 2nd edition. San Diego: Academic Press, 2001.
Larger varanids most likely have it ossify and visible on an xray while smaller species may have it remain cartilaginous, hence not showing up on an xray. A human child's xray looks as if they have no kneecaps until the patella ossifies. Gout is uric acid deposits in and around synovial JOINTS that has a much different xray appearance. It presents on an xray as a slightly opaque, irregularly edged mass or "tophus". If they have chronic dehydration and are passing firm urate pellets, the appearance is different than a hemibaculum IMO.