The effects of low-dose radiation on articular cartilage: a review.

Articular cartilage is a specialized connective tissue, predominately composed of water, collagen, and proteoglycans, that provides a smooth, lubricated surface for articulation in joints. It has long been considered radioinsensitive and therefore unaffected by exposure to radiation in medical settings. Due to the increased amount of yearly radiation exposure through radiotherapy and ionizing radiation diagnostic procedures, there has been a renewed interest in how radioinsensitive articular cartilage actually is. Despite this renewed interest, the majority of these studies do not focus on articular cartilage as their primary goal, but rather, have observed the effects of total body irradiation. Since many of these studies do not report the type of irradiation used, the rate of exposure, or use consistent models, there are inconsistencies in these studies, which make comparing and translating the results difficult. Previous literature reviews have found less than 60 studies discussing the effects of radiation on articular cartilage and its components both in vitro and in vivo. However, despite the inconsistencies, these reviews and studies have drawn the same overall conclusion that this research needs to be continued and broadened in order to make a consistent conclusion on the radioinsensitivity of articular cartilage. Therefore, the goal of this review is to categorize and summarize current findings in literature discussing the effects of radiation on articular cartilage.