History

Fact Explanation
Severe joint pain Inflammatory mediators stimulate nociceptors and free nerve endings producing pain. And also increased intra-articular pressure due to swelling causes stretching of the capsule that contains nociceptors which produce severe pain.[1,4]
Joint swelling Inflammatory exudate causes increase of fluid in the tissues that surround the joint.[1,4]
Impaired range of movements Excessive pain, swelling of the joint and muscle spasms around the joint limit the range of movements.[1]
Fever Cytokines released by inflammatory cells change the temperature set point at a higher level, increasing body temperature which in turn manifests as fever.[1,3]
History of immunosuppressive state (diabetes, HIV infection, by immunosuppressive agents) Patients with these conditions have a higher risk of developing septic arthritis as their natural defense mechanisms (humoral and cell mediated immunity) of the body against pathogens are weaker than normal people.[1,3]
History of prosthetic joint replacement Joint prostheses is a foreign material to the body and good medium for bacteria growth which leads to biofilm formation.[1,5]
History of underlying joint disease (eg: pre-existing rheumatoid arthritis, osteoarthritis Presence of a chronically inflammed joint is a well recognized risk factor for development of septic arthritis. Symptoms in the affected joint/joints are out of propotion to the disease activity detected in other joints.[1,3]
History of sexually transmitted diseases Gonococcal arthritis caused by the bacteria Neisseria gonorrhoeae common among sexually active adolescents and a history of sexually transmitted disease increases the chance of developing gonococcal arthritis.[1,3]
History of penetrating trauma to the affected joint/site Trauma is the commonest cause for acute joint pain and swelling and particularly penetrating trauma can introduce micro-organisms to the joint cavity and produce septic arthritis.[3]
History of intravenous drug use IV drug users create a portal of entry for micro-organisms to the blood stream by breaching the skin barrier and help them to spread hematogenously.[1,3]
References
  1. HOROWITZ Diane Lewis , KATZAP Elena, et al. Approach to Septic Arthritis. American Family Physician. September 2011. vol 15;84(6):653-660. [viewed on 21.03.2014] Available at: http://www.aafp.org/afp/2011/0915/p653.html
  2. MATHEWS CJ, WESTON VC, et al. Bacterial septic arthritis in adults. Lancet. 2010. vol 375(9717):846–855. [viewed on 21.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pubmed/20206778
  3. TILL Simon H, SNAITH M L. Assessment, investigation, and management of acute monoarthritis. Journal of Accident and Emergency Medicine. 1999. vol 16:355-361. [viewed on 24.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1347058/pdf/jaccidem00032-0037.pdf
  4. PERROT S, Guilbaud G. Pathophysiology of joint pain. Rev Rhum Engl Ed. July-September 1996. vol 63(7-8):485-92. [viewed on 25.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pubmed/8896062#
  5. SAIMA AALAM, Rabih O. Darouiche. Prosthetic joint infections. Current infectious disease reports. October 2012. vol 14(5):551-557. [viewed on 25.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3433240/

Examination

Fact Explanation
Erythema Inflammation process causes vasodilatation and congestion of the surrounding tissue. This will give rise to local erythema over the affected joint.[1]
Joint effusion Inflammatory exudate causes increase of fluid in the tissues that surround the joint.[1,4]
Limitation of active and passive movements of the joint Associated pain, swelling and muscle spasms limit the range of movements.[1,2]
Pattern of joint involvement - monoarticular Septic arthritis is usually monoarticular. Polyarticular pattern can be seen when there is an underlying joint disease such as rheumatoid arthritis. Knee joint is the most commonly affected, followed by the hip, shoulder, ankle, elbow, and wrist.[1,4]
Draining sinus Can be seen in prosthetic joint infections.[1,3]
Increased body temperature and local increase in skin temperature over the joint Cytokines released by inflammatory cells change the temperature set point at a higher level, increasing body temperature which in turn manifests as fever.[1,4]
Joint line tenderness Inflammatory mediators stimulate pain receptors and cause severe pain. And also increased intra-articular pressure due to swelling, effusions stretches joint capsule and external compression activate nociceptors and causes pain.[1]
References
  1. HOROWITZ Diane Lewis, KATZAP Elena, et al. Approach to Septic Arthritis. American Family Physician. September 2011. vol 15;84(6):653-660. [viewed on 21.03.2014] Available at: http://www.aafp.org/afp/2011/0915/p653.html
  2. MATHEWS CJ, VC Weston , et al. Bacterial septic arthritis in adults. Lancet. 2010. vol 375(9717):846–855. [viewed on 21.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pubmed/20206778
  3. SAIMA AALAM, Rabih O. Darouiche. Prosthetic joint infections. Current infectious disease reports. October 2012. vol 14(5):551-557. [viewed on 25.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3433240/
  4. SIMON H TILL, Snaith M L . Assessment, investigation, and management of acute monoarthritis. Journal of Accident and Emergency Medicine. 1999. vol 16:355-361. [viewed on 24.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1347058/pdf/jaccidem00032-0037.pdf

Differential Diagnoses

Fact Explanation
Rheumatoid arthritis Typically presents as a slowly progressive, symmetrical, peripheral polyarthritis. (eg: involvement of small joints of both hands). Joint pain and stiffness characteristically worse in the morning and may improve with gentle activity. Compared to septic arthritis fever will be less prominent. On examination joint deformities can be observed. Since rheumatoid arthritis is an predisposing factor for septic arthritis, both conditions can co-exist. [1,3]
Osteoarthritis Difficult to differentiate acute flare up of monoarticular osteoarthritis from superimposed septic arthritis on a osteoarthritic joint. Joint pain will get worse with activity and joint locking/joint instability will be prominent. In osteoarthritis variable levels of Inflammatory signs (erythema, tenderness, swelling) can be seen and fever will be absent or less marked. On examination crepitus on movement, usually poly-articular joint involvement can be noted which is not found in isolated septic arthritis. Inflammatory markers (ESR, CRP) will be normal or slightly raised.[1,3,5]
Crystal induced arthritis (gout) Inflammed first metatarsophalangeal joint is a characteristic feature of gout. Consider if there are pre disposing factors such as hypertension, hyperlipidemia, excess alcohol intake, renal impairment and history of diuretic treatment.[3]
Reactive arthritis Is a sterile synovitis, which occurs following an infection. Associated conjunctivitis, urethritis and diarrhoea points towards reactive arthritis. Enthesitis is common causing plantar fasciitis or Achilles tendon enthesitis.[3]
Psoritic arthritis Seen in patients with psoriasis/with a family history of psoriasis. Distal interphalangeal arthritis is the most common pattern of joint involvement. On examination psoritic skin lesions, nail changes can be found.[3]
Inflammatory bowel disease related arthritis Episodes of bloody diarrhoea, features of malabsorption and weight loss indicate presence of inflammatory bowel disease.[3]
Ankylosing spondylitis Affects mainly young adults whereas septic arthritis commonly found in elderly people. Lower back pain/stiffness will be more prominent which get worse in the morning and improved with exercises.[3]
Hemarthrosis/traumatic injury Hemarthrosis is caused either by trauma (meniscal/cruciate tear) or clotting/bleeding disorder. Consider in a male patient who is diagnosed to have hemophilia or who has a family history of hemophilia. Trauma to a joint leading to hemarthrosis also can be mistakenly diagnose as acute septic arthritis.[3]
Connective tissue diseases - Systemic Lupus Erythematosis (SLE) Patient will have other features of SLE such as oral ulcers, photosensitivity rashes, discoid rashes, alopecia, other associated complications of SLE. Polyarticular pattern and involvement of small joints differentiate SLE arthritis from septic arthritis.[1,3,6]
Malignancy Severe nocturnal pain raises the suspicion of malignancy. On examination palpable bony mass, bony tenderness, palpable non inflammatory type lymph nodes can be found.[3]
Systemic disease (eg: infective endocarditis) Consider in a patient who has got risk factors for developing infective endocarditis (valvular heart disease, history of prosthetic heart valve insertion, intravenous drug users) [3]
Cellulitis overlying a joint Infection of the dermis and subcutaneous tissue is called cellulitis and it is characterized by tender, erythematous, edematous skin lesion with advancing boarders. Joint movements will be less affected compared to septic arthritis.[4]
References
  1. DIANE LEWIS HOROWITZ, Elena katzap, et al. Approach to Septic Arthritis. American Family Physician. September 2011. vol 15;84(6):653-660. [viewed on 21.03.2014] Available at: http://www.aafp.org/afp/2011/0915/p653.html
  2. MATHEWS CJ, Weston VC, et al. Bacterial septic arthritis in adults. Lancet. 2010. vol 375(9717):846–855. [viewed on 21.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pubmed/20206778
  3. SIVA C, Velazquez C, et al. Diagnosing acute monoarthritis in adults: a practical approach for the family physician. American Family Physician. July 2003. vol 1;68(1):83-90. [viewed on 24.03.2014] Available at:http://www.ncbi.nlm.nih.gov/pubmed/12887114
  4. DANIEL L. STULBERG, Marc A. Penrod, et al. Common Bacterial Skin Infections. American Family Physician. July 2002. vol 66(1):119-125. [Viewed on 25.03.2014] Available at: http://www.aafp.org/afp/2002/0701/p119.html
  5. KEITH SINUSAS. Osteoarthritis: Diagnosis and Treatment. American Family Physician. January 2012. vol 85(1):49-56. [Viewed on 25.03.2014] Available at: http://www.aafp.org/afp/2012/0101/p49.html
  6. JAMES M. GILL, Anna M. Quisel, et al. Diagnosis of Systemic Lupus Erythematosus. American Family Physician. December 2003. vol 68(11):2179-2187. [Viewed on 25.03.2014] Available at: http://www.aafp.org/afp/2003/1201/p2179.html

Investigations - for Diagnosis

Fact Explanation
Joint fluid analysis, culture and antibiotic sensitivity testing (ABST) Gram stain and culture of synovial fluid will identify the causative infectious agent. Polymerase chain reaction (PCR) testing of synovial fluid may help isolate less common organisms, such as Borrelia species, but should be ordered if there is a high level of clinical suspicion. PCR may allow more rapid and accurate diagnosis. Crystal analysis can be performed if we are suspecting gout. In synovial fluid, a WBC count of more than 50,000/mm3 and a polymorphonuclear cell count greater than 90% have been directly correlated with infectious arthritis. Cell count results are important as they will be available earlier than microbiological investigation results and clinician can proceed with empirical treatment. ABST will guide selection of the appropriate antibiotics.[1,3]
Blood culture and antibiotic sensitivity testing Because pathogenesis may be hematogenous, blood cultures are positive in 25 to 50 percent of patients with septic arthritis.[1,2]
Erythrocyte sedimentation rate or C reactive protein level Though these investigations are nonspecific often used to determine the presence of infection or inflammatory response. Elevated levels favours septic arthritis. Note: can be used to monitor therapeutic response.[1,5]
Full Blood Count Leucocytosis is usual unless the patient is severly immunocompromised.[5]
Plain X rays Plain X rays of the affected joints are not usually helpful, but may detect fractures, osteomyelitis, pre-existing joint disease, metallic foreign bodies and tumors.[1,5]
Ultrasound scan (USS) USS can be used to detect effusions. Also guide needle aspiration of certain accessible joints.[1,5]
Magnetic Resonance Imaging (MRI) More sensitive and specific for diagnosing joint infection. Acute intraarticular infection will show bone erosions with marrow edema. Additionally allow guided arthrocentesis, particularly in difficult-to-examine joints (e.g., hip, sacroiliac, costochondral). Note: Cannot use with certain metal joint implants. [1,2]
Scintigraphy (Bone scan) Can use to differentiate sepsis from osteoarthrosis but can not distinguish sepsis and other causes of joint inflammation.[6]
Biopsy of the synovium Not done routinely but Important in diagnosing fungal and mycobacterial infections. When there is a diagnostic challenge, this can be used to identify bacterial DNA in the synovium which is an important information in the diagnosis of infectious arthritis.[3,4]
Urine - Gram stain and culture Important to diagnose source of infection in reactive arthritis.[5]
Swabs from the urethra, cervix, throat Important in diagnosing gonococcal septic arthritis and reactive arthritis.[5]
References
  1. DIANE LEWIS HOROWITZ, Elena katzap, et al. Approach to Septic Arthritis. American Family Physician. September 2011. vol 15;84(6):653-660. [viewed on 21.03.2014] Available at: http://www.aafp.org/afp/2011/0915/p653.html
  2. MATHEWS CJ, Weston VC, et al. Bacterial septic arthritis in adults. Lancet. 2010. vol 375(9717):846–855. [viewed on 21.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pubmed/20206778
  3. SCHUMACHER HR JR. Synovial fluid analysis and synovial biopsy. In: Ruddy S, Harris ED, Sledge CB, Kelley WN, eds. Kelley's Textbook of Rheumatology. 6th ed. Philadelphia, Pa.: Saunders; 2001:605–619.
  4. BARRY BRESNIHAN. Are synovial biopsies of diagnostic value?. Arthritis Res Ther. October 2003. vol 5(6): 271–278. [viewed on 25.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC333414/ doi:10.1186/ar1003
  5. SIMON H TILL, M L Snaith. Assessment, investigation, and management of acute monoarthritis. Journal of Accident and Emergency Medicine. 1999. vol 16:355-361. [viewed on 24.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1347058/pdf/jaccidem00032-0037.pdf
  6. MATHEWS CJ, Kingsley G, Field M, et al. Management of septic arthritis: a systematic review. Annual Rheumatological Disorders. April 2007;66(4):440–445. [viewed on 25.03.2014] Availble at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1856038/

Management - General Measures

Fact Explanation
Antipyretics - paracetamol Patients will have high grade fever which need to be controlled.[1,2]
Analgesics - NSAIDs, Opioids Severe pain should be addressed promptly.[1,2]
Physical therapy Joint should be immobilized initially to relieve pain. When the condition responds adequately, begin gentle mobilization of the affected joint to prevent stiffness and muscle wasting. Till the signs and symptoms of synovitis have resolved, the weight bearing by the joint should be restricted The initial therapy consists of providing passive range-of-motion exercises while maintaining the joint in its functional position and .[1,3]
Prevention 1) Antibiotic prophylaxis for high risk patients with prosthetic joints. 2) Strictly adhere to sterile procedures involving the joint space. 3) Attend any infective foci promptly to lower the chance of bloodstream invasion.[1,2,4]
References
  1. DIANE LEWIS HOROWITZ, Elena katzap, et al. Approach to Septic Arthritis. American Family Physician. September 2011. vol 15;84(6):653-660. [viewed on 21.03.2014] Available at: http://www.aafp.org/afp/2011/0915/p653.html
  2. MATHEWS CJ, Weston VC, et al. Bacterial septic arthritis in adults. Lancet. 2010. vol 375(9717):846–855. [viewed on 21.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pubmed/20206778
  3. SIMON H TILL, M L Snaith. Assessment, investigation, and management of acute monoarthritis. Journal of Accident and Emergency Medicine. 1999. vol 16:355-361. [viewed on 24.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1347058/pdf/jaccidem00032-0037.pdf
  4. MATHEWS CJ, Kingsley G, Field M, et al. Management of septic arthritis: a systematic review. Annual Rheumatological Disorders. April 2007;66(4):440–445. [viewed on 25.03.2014] Availble at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1856038/

Management - Specific Treatments

Fact Explanation
Antibiotic treatment Must start empirically as soon as possible, since joint cartilage can be destroyed within days and also to prevent permanent disability. Should be based on the organism found in the Gram stain of the synovial fluid, or on the suspicion of a pathogen from the patient's clinical presentation. Empirical treatment options include, 1) Patients with no risk factors - Flucloxacillin 1-2g 6 hourly IV / erythromycin 1g 6 hourly IV and gentamicin IV 2) High risk of Gram negative sepsis - Cefuroxime 1.5g 8 hourly IV 3) MRSA risk - Vancomycin 4) Gonococcal arthritis - Ceftriaxone Antibiotic choice will need to modify according to the Gram stain and culture results. The duration of therapy in patients with nongonococcal septic arthritis is typically three to four weeks. The clinical response should be rapid, with symptoms improving within 24 to 48 hours. Treatment then may be switched to oral antibiotics.[1,3]
Evacuation of purulent material - arthrocentesis and surgical methods Effective evacuation of bacteria and inflammatory products are necessary for early recovery. Repeated daily joint aspirations are successful during the first five days of treatment. Open or arthroscopic techniques can be used to surgically drain the infected joint. Arthroscopic drainage is associated with rapid recovery and low morbidity. Also help in relieving pain. Another advantage is direct visualization of the joint tissue which facilitates the lysis of adhesions, drainage of purulent pockets, and debridement of necrotic material.[1,2,3]
Othe surgical interventions Removal of the infected prosthesis and reimplantation may be necessary, in prosthetic joint infections. After removing the infected prostheses joint space is filled with an antibiotic impregnated spacer for 3-6 weeks before a new prosthesis is inserted.[1,4]
References
  1. HOROWITZ Diane Lewis, KRATZAP Elena, et al. Approach to Septic Arthritis. American Family Physician. September 2011. vol 15;84(6):653-660. [viewed on 21.03.2014] Available at: http://www.aafp.org/afp/2011/0915/p653.html
  2. CARPENTER Christopher R , SCHUUR Jeramiah D, et al. Evidence based-Diagnostics: Adult septic arthritis. Acadamy of Emergency Medicine. August 2011. vol 18(8): 781–796. [viewed on 24.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3229263/ doi: 10.1111/j.1553-2712.2011.01121.x
  3. MATHEWS CJ, Kingsley G, Field M, et al. Management of septic arthritis: a systematic review. Annual Rheumatological Disorders. April 2007;66(4):440–445. [viewed on 25.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1856038/
  4. SAIMA AALAM, Rabih O. Darouiche. Prosthetic joint infections. Current infectious disease reports. October 2012. vol 14(5):551-557. [viewed on 25.03.2014] Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3433240/