Background: Knee osteoarthritis (OA) is a prevalent degenerative disease affecting synovial joints, predominantly the knee, leading to various complications, including mental health conditions like depression and anxiety. This systematic review aimed to determine the prevalence of depression and anxiety in knee OA patients. Methods: A comprehensive literature search was conducted in various databases till September 15, 2023. Studies focusing on the prevalence of mental health issues in patients with knee OA were included, excluding narrative reviews, protocols, unpublished reports, editorials, case reports, abstracts, and commentaries. All statistical analyses were performed in R version 4.2.3. Results: This review included a total of 14 studies involving middle-aged to elderly adult patients with knee OA, with ages ranging from 45 to 75 years. Among these, 13 studies involving 3390 adult patients with an average age of 59.75 years reported a pooled prevalence of depression of 30% (95% confidence interval: 18–43), demonstrating a substantial heterogeneity (I ²=98%). Additionally, anxiety was identified with a combined prevalence of 27% (95% confidence interval: 24–30) based on three studies that included 1407 older adult patients with an average age of 62.1 years. These studies displayed minimal heterogeneity (I ²=7%). Conclusion: The findings show a significant prevalence of depression among adult patients with knee OA and anxiety among older adults with knee OA, emphasizing the need for integrated healthcare approaches that address both orthopedic and mental health conditions. More comprehensive research is essential to deepen our understanding of the connection between mental illnesses and knee OA and to develop effective preventive and treatment strategies.

Periodontitis, a chronic inflammatory disease of the gums affects both the ligament and alveolar bone. A severe form of periodontal disease affects a strikingly high number of one billion adults globally. The disease permutes both the soft and hard tissues of the oral cavity leading to localized and systemic diseases. Periodontitis has a deleterious impact on systemic health causing diabetes, cardiovascular diseases (CVD), and other disease. The cause of the enhanced inflammatory process is due to dysbiosis and an unregulated immune response. Innate immune response and T cells trigger uninhibited cytokine release causing an unwarranted inflammatory response. The RANK- RANKL interaction between osteoblasts, immune cells, and progenitor osteoclasts results in the maturation of osteoclasts, which promote bone resorption. It is well established that dysbiosis of the oral cavity has been implicated in periodontitis. But emerging reports suggest that the pulmonary pathogen, Mycobacterium tuberculosis (Mtb), causes extrapulmonary diseases such as periodontitis. Many clinical case reports advocate the involvement of Mtb in periodontitis, which poses a threat with the surge of tuberculosis in HIV and other immunocompromised individuals. Fostering a better understanding of the mechanism, causative agents and control on inflammatory response is imperative in the prevention and treatment of periodontitis.