Rare musculoskeletal (MSK) conditions can be challenging to recognize and are thus often missed owing to a low index of suspicion. This chapter discusses the MSK manifestations of amyloid arthropathy, sickle cell disease, Jaccoud’s arthropathy, and arthritis robustus. The MSK manifestations of these rare conditions have not been studied in detail in medical literature. Once diagnosed, their management usually consists of supportive care and treatment of the underlying medical disorder. Timely recognition and optimal management of the underlying conditions usually improve the MSK manifestations of these rare entities, however, specific therapies are required in certain conditions.