Cardiovascular System (I00-I99).
- Peripheral arterial occlusive disease (pAVD) – progressive narrowing or occlusion of the arteries supplying the arms/ (more commonly) legs, usually due to atherosclerosis (arteriosclerosis, hardening of the arteries).
Musculoskeletal system and connective tissue (M00-M99).
- Arthritis (inflammation of the joint); possibly also septic arthritis: knee joint is the most common site of localization; clinical symptoms: in addition to pain, swelling, redness and hyperthermia of the joint, in severe cases also fever and a general feeling of illness
- Aseptic bone necrosis – collective term for necrosis (“cell death”) of bones that occur in the absence of infection (“aseptic”) due to ischemia (reduced supply of blood).
- Bursitis (inflammation of the bursa).
- Gout (arthritis urica/uric acid-related joint inflammation or tophic gout)/hyperuricemia (elevation of uric acid levels in the blood) or gout attack (“gonagra”) (isolated gouty arthropathy of the knee joint is rare).
- Hip joint diseases that project to the knee.
- Insertion tendinopathy – pain conditions arising from irritation at the junction between tendons and bones, ie in the area of insertion.
- Meniscal damage – often an acute onset with a history of trauma.
- Ahlbäck’s disease – aseptic bone necrosis, i.e. not caused by infection.
- Osteochondrosis dissecans – circumscribed aseptic bone necrosis below the articular cartilage, which can end with the rejection of the affected bone area with the overlying cartilage as a free joint body (joint mouse); this often causes irritation.
- Reactive arthritis (synonym: post-infectious arthritis / joint inflammation) – secondary disease after gastrointestinal (gastrointestinal tract concerning), urogenital (urinary and genital organs concerning) or pulmonary (lungs concerning) infections; refers to an arthritis, where pathogens in the joint (usually) can not be found (sterile synovialitis).
- Reiter’s disease (synonyms: Reiter’s syndrome; Reiter’s disease; arthritis dysenterica; polyarthritis enterica; postenteritic arthritis; posturethritic arthritis; undifferentiated oligoarthritis; urethro-oculo-synovial syndrome; Fiessinger-Leroy syndrome; English Sexually acquired reactive arthritis (SARA)) – special form of a “reactive arthritis” (see above. ); secondary disease after gastrointestinal or urogenital infections, characterized by the symptoms of Reiter’s triad; seronegative spondyloarthropathy, which is triggered especially in HLA-B27 positive persons by an intestinal or urinary tract disease with bacteria (mostly chlamydia); Can manifest as arthritis (joint inflammation), conjunctivitis (conjunctivitis), urethritis (urethritis) and partly with typical skin changes.
- Rheumatoid arthritis – inflammatory multisystem disease, which usually manifests itself in the form of synovitis (synovitis) (is also associated with morning stiffness; lifetime prevalence: -1%; second most common inflammatory joint disease).
Neoplasms – tumor diseases (C00-D48).
- Metastases (daughter tumors)
- Tumors, unspecified
Psyche – nervous system (F00-F99; G00-G99)
- Neurogenic disorders – disorders affecting the nerves.
General differential diagnoses for osteoarthritis
Blood, blood-forming organs – immune system (D50-D90).
- Sarcoidosis (synonyms: Boeck’s disease; Schaumann-Besnier’s disease) – systemic disease of connective tissue with granuloma formation.
Skin and subcutaneous (L00-L99).
- Psoriasis (psoriasis)
Mouth, esophagus (food pipe), stomach, and intestines (K00-K67; K90-K93).
- Whipple’s disease – rare systemic infectious disease; caused by the gram-positive rod bacterium Tropheryma whippelii (from the actinomycete group), which can affect several other organ systems in addition to the obligately affected intestinal system and is a chronic recurrent disease; symptoms: Fever, arthralgia (joint pain), brain dysfunction, weight loss, diarrhea (diarrhea), abdominal pain (abdominal pain), and more.
- Celiac disease (gluten-induced enteropathy) – chronic disease of the mucosa of the small intestine (small intestinal mucosa), which is based on hypersensitivity to the grain protein gluten.
Musculoskeletal system and connective tissue (M00-M99).
- Arthritis (inflammation of the joints)
- Chondrocalcinosis (synonym: pseudogout); gout-like disease of the joints caused by deposition of calcium pyrophosphate in the cartilage and other tissues; leads, among other things, to joint degeneration (often of the knee joint); symptomatology resembles an acute gout attack
- Disc hernia (herniated disc).
- Enteropathic arthritis – occurrence of joint inflammation in the course of enterocolitis (intestinal inflammation).
- Gout (arthritis urica/uric acid-related joint inflammation or tophic gout)/hyperuricemia (elevation of uric acid levels in the blood) (isolated gouty arthropathy of the knee joint is rare)
- Behçet’s disease (synonym: Adamantiades-Behçet’s disease; Behçet’s disease; Behçet’s aphthae) – multisystem disease from the rheumatic form circle, which is associated with recurrent, chronic vasculitis (vascular inflammation) of the small and large arteries and mucosal inflammation; The triad (the occurrence of three symptoms) of aphthae (painful, erosive mucosal lesions) in the mouth and aphthous genital ulcers (ulcers in the genital region), as well as uveitis (inflammation of the middle eye skin, which consists of the choroid (choroid), the corpus ciliary (corpus ciliare) and the iris) is stated as typical for the disease; a defect in cellular immunity is suspected
- Bekhterev’s disease (ankylosing spondylitis; Latinized Greek: spondylitis “inflammation of the vertebrae” and ankylosans “stiffening”) – chronic inflammatory rheumatic disease with pain and stiffening of joints.
- Progressive systemic sclerosis – systemic disease with hardening of the skin and internal organs.
- Psoriatic arthritis (arthritis due to psoriasis).
- Reactive arthritis (synonym: post-infectious arthritis / joint inflammation) – second disease after gastrointestinal (gastrointestinal tract concerning), urogenital (urinary and genital organs concerning) or pulmonary (lungs concerning) infections; refers to an arthritis, where pathogens in the joint (usually) can not be found (sterile synovialitis).
- Reiter’s disease (synonyms: Reiter’s syndrome; Reiter’s disease; arthritis dysenterica; polyarthritis enterica; postenteritic arthritis; posturethritic arthritis; undifferentiated oligoarthritis; urethro-oculo-synovial syndrome; Fiessinger-Leroy syndrome; English Sexually acquired reactive arthritis (SARA)) – special form of a “reactive arthritis” (see above. ); secondary disease after gastrointestinal or urogenital infections, characterized by the symptoms of Reiter’s triad; seronegative spondyloarthropathy, which is triggered especially in HLA-B27 positive persons by an intestinal or urinary tract disease with bacteria (mostly chlamydia); Can manifest as arthritis (joint inflammation), conjunctivitis (conjunctivitis), urethritis (urethritis) and partly with typical skin changes.
- Rheumatoid arthritis – chronic inflammatory multisystem disease, which usually manifests itself in the form of synovitis (inflammation of the synovial membrane). It is also referred to as primary chronic polyarthritis (PcP). (Lifetime prevalence: -1%; second most common inflammatory joint disease).
- Systemic lupus erythematosus (SLE) – systemic disease affecting the skin and connective tissue of the vessels, leading to vasculitides (vascular inflammation) of numerous organs such as the heart, kidneys or brain.
