2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Diseases Of The Musculoskeletal System And Connective Tissue 710-739 > Dorsopathies 720-724 > Spondylosis And Allied Disorders 721.* > 2006 ICD-9-CM Diagnosis 721.6 Ankylosing vertebral hyperostosis View the most recent version of ICD-9-CM 721.6 A disease of elderly men characterized by large osteophytes that bridge vertebrae and ossification of ligaments and tendon insertions. 721.6 is a specific code that can be used to specify a diagnosis 721.6 contains 2 index entries View the ICD-9-CM Volume 1 721.* hierarchy  Index entries containing 721.6: Hyperostosis 733.99 vertebral 721.8 ankylosing 721.6 Spondylitis 720.9 ossificans ligamentosa 721.6