Septic arthritis

Septic arthritis is a rapidly progressive infectious disease of the joints, caused by the direct ingress of pyogenic microorganisms into the joint cavity.

ICD-10 code

• M00.0-M00.9 Septic arthritis.
• A.54.4 Gonococcal infection of the musculoskeletal system.
• 184.5 Infection and inflammatory response due to endoprosthetics.

Epidemiology

Septic arthritis and infection of the prosthetic joint are found everywhere. They account for 0.2-0.7% of all hospitalizations. Children and people of older age groups are most often ill. The incidence of septic arthritis is 2-10 per 100 000 population, among RA patients - 30-40 cases per 100 000. The prevalence of infection of the prosthetic joint is 0.5-2.0% of all prosthetic cases a year.

[1], [2], [3], [4], [5], [6]

What causes septic arthritis?

All known bacteria can cause septic arthritis. The most common etiologic agent of septic arthritis is Staphylococcus aureus (37-56%), which accounts for up to 80% of cases of joint infections in RA patients and diabetes mellitus. S. Aureus is also considered the main etiological factor in infectious cocksites and polyarticular variants of septic arthritis. Streptococcus take second place in the frequency of detection in the face of septic arthritis (10-28%). Inflammation of the joints caused by streptococci is usually associated with background autoimmune diseases, chronic skin infection and previous trauma. Gram-negative rods (10-16%) cause septic arthritis in the elderly, drug addicts, "injecting drugs intravenously, as well as in patients with immunodeficiency. Septic arthritis caused by Neisseria gonorrhoeae (0.6-12%) is detected, as a rule, within the disseminated gonococcal infection. Anaerobes as causative agents (1.4-3.0%) appear in recipients of joint prostheses, in persons with deep infections of soft tissues and in patients with diabetes mellitus.

Structure of infectious agents of prosthetic joint infection:

• Gram-positive aerobes - 64-82%, including Staphylococcus epidermidis - 29-42%;
• Staphylococcus aureus - 17-22% $
• Streptococcus spp. - 8-10%;
• Enterococcus sp. - 4-5%;
• diphtheria - 2%;
• gram-negative aerobes - 9-23%;
• anaerobes - 8-16%;
• fungal and mixed flora - 2-5%.

Early forms of infection of the prosthetic joint (up to 3 months after implantation of the prosthesis) are caused mainly by Staphylococcus epidermidis. Colonization of the endoprosthesis with staphylococci occurs via contact from infected skin, subcutaneous adipose tissue, muscle, or from a postoperative hematoma. Late forms of infection of the prosthetic joint are due to infection by other microorganisms, occurring predominantly by the hematogenous pathway.

How does septic arthritis develop?

Normally, the articular tissues are sterile, which is ensured by the successful functioning of the phagocytes of the synovial membrane and the synovial fluid. The development of septic arthritis requires the presence of a number of "risk factors". The most significant include the weakening of the natural defenses of the macroorganism due to old age, severe concomitant diseases (diabetes mellitus, cirrhosis, chronic renal failure, oncological diseases, etc.), as well as the presence of primary foci of infection (pneumonia, pyelonephritis, pyoderma, ). No less important are the background articular pathology (hemarthrosis, osteoarthritis), the presence of joint prostheses, as well as the ongoing (in connection with this therapy and its possible complications.) Hematogenous spread of pathogens is greatly facilitated by various manipulations, including intravenous administration of drugs (including drugs ), catheterization of the central veins, as well as penetrating stab wounds and bites.An essential disorders in the development of septic arthritis can be congenital disorders of phagocytosis associated with lack accuracy of complement and violation of chemotaxis.

The penetration of the pathogen into the joint by the hematogenous path occurs in the period of transient or persistent bacteremia, lymphogenous - from the foci of infection nearest to the joint, as well as in direct contact caused by medical manipulations (arthrocentesis, arthroscopy) and penetrating injuries.

The penetration of bacteria into the joint causes an immune response, accompanied by the release of proinflammatory cytokines and immunocompetent cells into the joint cavity. Their accumulation entails inhibition of the process of repair of cartilaginous tissue and its degradation, followed by the destruction of cartilage and bone tissue and the formation of bone ankylosis.

How is septic arthritis manifested?

Septic arthritis is characterized by a sharp onset with intense pain and other signs. In most cases (60-80%) patients are worried about fever. However, body temperature can be subfebrile and even normal, which is more common in hip and sacroiliac joints, against the background of active anti-inflammatory therapy of the underlying disease, as well as in elderly patients. In 80-90% of cases, a single joint is affected, more often the knee or hip. The development of the infectious process in the hands mostly has traumatic genesis (penetrating stab wounds or bites). Oligoarticular or polyarticular type of lesion is more often observed in the development of septic arthritis in patients with systemic connective tissue diseases, as well as in drug addicts injecting intravenously. In addition, in "intravenous" drug addicts, septic arthritis is characterized by a slower onset, prolonged course and frequent sacroiliac and sternoclavicular articulations, pubic symphysis.

With the development of septic arthritis within the disseminated gonococcal infection, clinical symptoms unfold within 2 to 3 days after the onset of the disease and includes general malaise, fever, skin rashes and teposinovitis.

The onset of infection of the prosthetic joint may be acute or subacute depending on the virulence of the pathogen. There are pain (95%), fever (43%), swelling (38%), with drainage or puncture get a purulent discharge (32%).

How to recognize septic arthritis?

The main attention is paid to the presence of "risk factors" predisposing to the development of septic arthritis. One of the most significant components of the onset of septic arthritis is the weakening of the body's natural defenses, due to concomitant diseases, immunosuppressive therapy, and elderly patients. Important importance is attached to the background pathology of the musculoskeletal system, as well as possible complications of its treatment.

Predisposing factors of gonococcal septic arthritis in women include menstruation, pregnancy, postpartum period, chronic asymptomatic endocervical infection. For men, homosexuality may become a risk factor. For people of both sexes, several predisposing factors are identified (extragenital gonococcal infection, promiscuous sexual intercourse, low socioeconomic and educational status, drug use, HIV infection, congenital deficiency of components C3, C4 complement).

The main risk factors for the infection of the prosthetic joint include immunodeficiency states, repeated and prolonged surgical interventions, prosthetics of superficial joints (ulnar, brachial, ankle).

Physical examination

Along with an intense pain syndrome, swelling, skin flushing and hyperthermia of the affected joint are revealed. When the process is localized in the hip or sacroiliac joints, pain in the lower back, buttocks and but the front surface of the thigh is often noted. In such situations, special samples can be useful: in particular, Patrick's test or the FABERE symptom (the initial letters of the Latin words flexio, abductio, externa rotatio, extensio) help to identify the pathology of the hip joint. When performing this test, the patient lying on the skip bends one leg in the hip and knee and touches the lateral ankle to the patella of another elongated leg. Pressure on the knee of the bent leg in case of injury causes pain and hip joint. A positive symptom of Ganslen (pain in the area of the sacroiliac joint with maximum flexion of the joints of the foot on the same side and maximum extension on the other side) indicates the presence of sakroileitis.

In young children, the only manifestation of bacterial coxitis can be severe pain while moving with fixation of the hip joint in the flexion and external rotation position

Gonococcal septic arthritis is often accompanied by the affected skin and the periarticular soft tissue. Gonococcal dermatitis develops in 66-75% of patients with disseminated gonococcal infection and is characterized by painless hemorrhagic papular or pustular eruptions, having a diameter of 1 to 3 mm with localization in the distal extremities. It is possible to form blisters with hemorrhagic contents. In typical cases, a pustule with a hemorrhagic or necrotic center is formed, surrounded by a purple halo. As a rule, the rash undergoes reverse development within 4-5 days and leaves after itself unstable pigmentation. Tenosynovitis develops in 2/3 of patients with disseminated gonococcal infection, has an asymmetric character, affects primarily the tendon sheaths of the hands and feet, and proceeds in parallel with skin changes. Within the disseminated gonococcal infection, it is possible to develop hepatitis, myopericarditis, extremely rarely endocarditis, meningitis, perihepatitis (Fitz-Hugh-Curtis syndrome), adult respiratory distress syndrome and osteomyelitis.

Laboratory diagnosis of septic arthritis

In the analysis of peripheral blood in patients with septic arthritis, leukocytosis is detected with a shift of the leukocyte formula to the left and a significant increase in ESR. However, in 50% of patients on septic arthritis, developed against RA and treatment with glucocorticoids, the number of leukocytes can be within the norm.

The basis for the diagnosis of septic arthritis is a detailed analysis of synovial fluid (including microbiological examination) obtained by puncture of the affected area. Immediately after taking the synovial fluid, it is sown (at the patient's bed) on nutrient media for aerobic and anaerobic pathogens. For obtaining preliminary information about the pathogen and prescribing empirical antibiotic therapy, it is necessary to stain Gram's synovial fluid smears, preferably with a preliminary centrifugation of the synovial fluid. In this case, the diagnostic informative value of the method is 75% and 50% when infected with Gram-positive cocci and Gram-negative rods, respectively. Visually synovial fluid with septic arthritis has a purulent character, grayish-yellow or bloody, muddy, dense, with a large amorphous precipitate. The number of leukocytes in the synovial fluid often exceeds that of other inflammatory diseases and is more than 50,000 / mm3, and often more than 100,000 / mm3 with a predominance of neutrophils (> 85%). In the synovial fluid, there is also a low glucose content, which is less than half of its serum concentration, and a high level of lactic acid. Blood cultures give rise to microflora in 50% of cases.

If a gonococcal etiology of septic arthritis is suspected, a bacteriological study of the discharge from the urethra (in men) or the cervix (in women) is indicated. In order to suppress the saprophyte flora, the crops are performed on selective media with the addition of antibiotics (Tayer-Martin medium). In the case of gonococcal infection, a positive result with a single foal is obtained in 80-90% of cases. Given the possibility of an associated infection, all patients with gonococcal infection are recommended to be screened for chlamydia and other sexually transmitted diseases (syphilis, HIV infection, etc.).

In patients with prosthetic joint infection, a histological and microbiological examination of the bone tissue biopsy taken near the cement-prosthesis joint is performed to verify the diagnosis and control the treatment.

Instrumental research

Radiologic examination of the joint is one of the first diagnostic measures, as it allows to exclude concomitant osteomyelitis and to determine the further tactics of examination and treatment of the patient. However, it should be noted that distinct and imputation on radiographs with septic arthritis (osteoporosis, narrowing of the joint gap, marginal erosion) appear about the 2nd week after the onset of the disease.

Radioisotope scanning with technetium, gallium or indium is especially important in cases when the joint being examined is deep in tissues or hard to reach for palpation (hip, sacroiliac). These methods help to identify the changes inherent in septic arthritis (the accumulation of radiopharmaceuticals, indicative of an active synovitis), and the early stages of the process, i.e. During the first two days, when radiological changes are still absent.

CT scan reveals destructive changes in bone tissue much earlier than radiography. This method is most informative for lesions of sacroiliac and sternoclavicular joints.

MRI reveals in the early stages of the disease edema of soft tissues and effusions in the joint cavity, as well as osteomyelitis.

Differential diagnostics

Septic arthritis should be differentiated from the following diseases manifested by acute monoarthritis: acute gouty attack, pyrophosphate arthropathy (pseudogout), RA, seronegative spondyloarthritis, Lyme borreliosis. Infection is considered one of the few urgent situations in rheumatology, requiring rapid diagnosis and intensive treatment in order to avoid irreversible structural changes. Therefore, there is a rule that every acute monoarthritis should be regarded as infectious, until proven otherwise.

[7], [8], [9], [10], [11], [12], [13], [14]

Example of the formulation of the diagnosis

• Acute bacterial staphylococcus coxarthritis (Staphylococcus aureus) etiology.
• Acute staphylococcal (Staphylococcus epidermidis) infection of the prosthetic hip joint.

[15], [16], [17], [18], [19], [20]

Treatment of septic arthritis

Non-drug treatment

Drainage of the infected joint is carried out (sometimes several times a day) by the method of closed aspiration through the needle. Remove the maximum possible amount of effusion. To assess the effectiveness of treatment, each time the count of leukocytes, Gram staining and synovial fluid cultures are performed. During the first two days, the joints are immobilized. Beginning with the third day, the diseases are carried out by passive movement, to the loads and active movements pass after the disappearance of arthralgias.

Medication-based baking

Antibacterial therapy is carried out for a period of two days empirically, taking into account the age of the patient, the clinical picture of the disease and the results of staining of the synovial fluid by Gram, in the future, taking into account the isolated pathogen and its antibiotic resistance. Antibiotics should be administered, mainly parenterally, intra-articular use of their use is inappropriate.

The absence of positive dynamics after two days of treatment dictates the need to replace the antibiotic. The remaining elevated ESR serves as an indication for the extension of treatment, which on average is 3-4 weeks (sometimes up to 6 over), but at least two weeks after the elimination of all signs of the disease.

In patients with prosthetic joint infection, antibiotic therapy is prescribed based on a microbiological examination of the bone biopsy and conducted for at least 6 weeks according to the following regimens: oxacillin + rifampicin, nancomycin + rifampicin, cefenim / ceftazidime + ciprofloxacin.

Antibiotics of choice for the treatment of gonococcal septic arthritis are cephalosporins of the third generation - ceftriaxone (1-2 g / day intravenously) or cefotaxime (3 g / day in 3 injections intravenously), administered within 7-10 days. Further oral therapy with ciprofloxacin (1 g / day in 2 doses) or ofloxacia (800 mg / day in 2 doses). Persons under the age of 18 lay down and patients with intolerance fluoroquinolonone prescribe cefixime (800 mg / day inward in 2 doses),

The timing of antibiotic therapy for gonococcal septic arthritis should be at least two weeks after the elimination of all signs of the disease. Given the high likelihood of concomitant Chlamydia infection, the above treatment regimens are supplemented with azithromycin (1 g orally) or doxycycline (200 mg / day orally in 2 doses for 7 days).

In addition to antimicrobial therapy, analgesics and NSAIDs are prescribed (diclofenac 150 mg / day, ketoprofen 150 mg / day, nimesulide 200 mg / day, etc.).

Surgery

Open surgical drainage with septic arthritis is carried out with the following indications: infection of the hip and, possibly, the shoulder joint; osteomyelitis of the vertebrae, accompanied by compression of the spinal cord; anatomical features that impede joint drainage (eg, sternoclavicular joint): the inability to remove pus with closed drainage through the needle due to increased viscosity of the contents or adhesions in the joint cavity; inefficiency of closed aspiration (persistence of the pathogen or absence of a decrease in leukocytosis in the synovial fluid): prosthetic joints; concomitant osteomyelitis requiring surgical drainage; septic arthritis, which developed as a result of foreign body entry into the joint cavity; late onset of therapy (more than 7 days).

Surgical treatment of the infection of the prosthetic joint is carried out in the following ways.

• Simultaneous arthroplasty with excision of infected tissues, installation of a new prosthesis and subsequent treatment with antibiotics. At the same time, the course of antibiotic therapy should be at least 4 or 6 months when the process is localized in the hip or knee joint, respectively.
• Excision of prosthetic components, contaminated areas of the skin and soft tissues followed by antimicrobial therapy for 6 pel. Then tissue biopsy is performed from the affected joint area, with antibiotic treatment being stopped for two weeks until the results of histological and microbiological studies are obtained, and then reimplantation is performed. In the absence of inflammatory changes in the biopsy specimens and the growth of microorganisms, antibiotic therapy is not renewed. Otherwise, antibiotic treatment is continued for 3 or (> months.

Indications for consultation of other specialists

All patients with septic arthritis are examined by an orthopedic surgeon to clarify the indications for open drainage, as well as prosthetics (or re-prosthetics) of the infected joint. With gonococcal etiology of septic arthritis, it is advisable to consult a dermatovenerologist for a long time agreeing on the tactics of treatment and further monitoring the patient and his sexual partner.

Further management

Treatment of the underlying disease in the recipient of joint prostheses using antibacterial prophylaxis according to indications. It is also recommended to give out a memo on patients hands indicating the principles of prevention of bacterial infection and infection of the prosthetic joint.

How to prevent septic arthritis?

There are no data on the prevention of septic arthritis. The likelihood of infection of the prosthetic joint increases significantly during the period of bacteremia that occurs with dental and urological manipulations. In this regard, experts from the American Orthopedic Surgery Academy, the American Dental Association and the American Urological Association have developed antibiotic prevention regimens for people at high risk for endoprosthesis infection.

Prophylaxis of prosthetic joint infection should be carried out to all recipients of joint prostheses within the first two years after the operation; patients with immunodeficiency due to drug or radiotherapy; patients who had previously suffered an infection of the joint prosthesis. It is also necessary to prevent people with concomitant pathology (hemophilia, HIV infection, type 1 diabetes mellitus, malignant neoplasms), performing dental procedures that exclude tooth extraction, periodontal manipulation, implant placement, etc. The above categories of patients should receive antibacterial agents with a variety of manipulations associated with possible disruption of the integrity of the mucous membrane of the urinary tract (lithotripsy, zodoscopy, transrectal prostate biopsy, etc.)

What prognosis does septic arthritis have?

In the absence of serious background diseases and timely adequate antibiotic therapy, the outlook is favorable. Irreversible loss of joint function develops in 25 50% of patients. Mortality in septic arthritis depends on the age of the patients, the presence of concomitant pathology (eg, cardiovascular, kidney disease, diabetes) and the severity of immunosuppression. The frequency of deaths in a disease such as septic arthritis has not significantly changed over the past 25 years and is 5-15%.