Abstract： Knee osteoarthritis （KOA） and sarcopenia are highly comorbid degenerative diseases in the elderly population． Based on the traditional Chinese medicine theory of disharmony between bone and muscle， this paper elucidates the pathogenetic relationship between KOA and sarcopenia from the perspective of spleen-kidney deficiency and malnutrition of bone and muscle. It proposes that the root of this comorbidity lies in spleen deficiency with impaired transportation and transformation，and kidney essence deficiency，while phlegm blended with blood stasis constitutes the manifestation． The treatment adopts strengthening the spleen and tonifying the kidney as the basic method， combined with promoting qi circulation and invigorating blood， dissolving phlegm and removing stasis， and supplemented by external therapies and rehabilitation measures， reflecting a holistic treatment strategy. This paper discusses the application of the disharmony between bone and muscle theory in the management of KOA and sarcopenia comorbidity， aiming to provide a reference for the understanding of its pathogenesis and clinical differentiation and treatment in traditional Chinese medicine．