Solid periosteal pattern is thought to evolve from single layer and multilayered periosteal reactions, forming a solid layer of mature new bone adjacent to the cortex. It denotes a longstanding pathological process.
1. William Palmer, Laura Bancroft, Fiona Bonar, Jung-Ah Choi, Anne Cotten, James F. Griffith, Philip Robinson, Christian W.A. Pfirrmann. Glossary of terms for musculoskeletal radiology. (2020) Skeletal Radiology. doi:10.1007/s00256-020-03465-1 - Pubmed
2. Wenaden AE, Szyszko TA, Saifuddin A. Imaging of periosteal reactions associated with focal lesions of bone. Clin Radiol. 2005 Apr;60(4):439-56. PubMed