Joint infection after artificial joint replacement
Introduction
Introduction to joint infection after artificial joint replacement Infection after artificial joint replacement is a serious, "catastrophic" complication. The initial infection rate was greater than 10%. With the rich experience, the infection after hip and knee arthroplasty has been reduced to 1% to 3%. However, with the increasing use of arthroplasty and the increasing number of operations, postoperative infection has become a very important issue. After artificial joint replacement, purulent infection is a very serious complication. Although the infection rate has dropped from about 10% in the early years to the current 1% to 3%, the number of patients with concurrent infections has gradually increased due to the increasing use of artificial joint replacement. basic knowledge The proportion of sickness: 0.01% Susceptible people: no special people Mode of infection: non-infectious Complications: genitourinary mycoplasma infection fracture
Cause
Causes of joint infection after artificial joint replacement
(1) Causes of the disease
Infection after artificial joint replacement should be regarded as nosocomial infection, and the pathogenic bacteria are highly resistant, the most common being staphylococci, accounting for 70% to 80%, Gram-negative bacilli, anaerobic bacteria and non-A group streptococci. common.
(two) pathogenesis
There are two types of infections: one is early infection, the other is late infection or late infection. Early infection is caused by bacteria directly entering the joint during surgery. Staphylococcus epidermidis is common, and late infection is mostly bloody. Caused by more common Staphylococcus aureus, joints that have been operated on, are more susceptible to infection, such as re-repair after artificial joint replacement, the infection rate is 10%, because of the high rate of joint replacement in rheumatoid arthritis .
Prevention
Prevention of joint infection after artificial joint replacement
1. Preoperative and intraoperative antibiotics, preoperative application, can prevent bacteremia; intraoperative use, so that the incision exudate contains an effective concentration of antibiotics.
2. Strict aseptic technique, the operating room uses ultra-clean measures.
3. Use bone cement that contains and releases antibiotics.
4. Shorten the surgical exposure time.
5. Use antibiotics for 7 to 10 days after surgery to prevent bacteria from spreading through the blood into the joint area being repaired.
Complication
Complications of joint infection after artificial joint replacement Complications genitourinary mycoplasma infection fracture
Specific complications of total hip arthroplasty include: neurovascular injury, peripheral organ damage, hemorrhage and hematoma, limb length, postoperative joint instability and dislocation, heterotopic ossification, thromboembolism, fracture, late loosening, infection , osteolysis, broken prosthesis, etc. Clohisy et al reviewed the reasons for revision of hip revision patients between 1996 and 2003, and found that aseptic loosening accounted for 55%, instability accounted for 14%, infection accounted for 7%, periprosthetic fracture accounted for 5%, and prosthesis fractured. 1%. Among them, aseptic loosening is the most important cause of renovation. Some of these complications can seriously affect postoperative function, such as fractures, dislocations, infections, etc., while others may endanger the patient's life, such as pulmonary embolism caused by thromboembolism.
Symptom
Symptoms of joint infection after artificial joint replacement Common symptoms Joint swelling Joint pain Increased bone density Acute pain Periosteal reaction Urinary tract infection Leukocytosis
Most infections occur within a few months after surgery, and can occur as early as two weeks after surgery, but also as late as a few years. Early manifestations include acute joint swelling, pain and fever, and fever symptoms must be differentiated from other complications. Such as postoperative pneumonia, urinary tract infection, etc., continuous joint pain must be differentiated from the pain caused by mechanical loosening of the prosthesis, the pain of infection is even worse at night, deep pain or deep pain in the deep, the symptoms can be alleviated after the application of antibiotics, The mechanical looseness of the prosthesis is related to exercise or weight bearing, and is aggravated by strenuous exercise. It must be clear that the infection is limited to superficial tissue, or deep and joint. If the wound drainage is purulent, it does not respond to antibiotic treatment. Deep infections around the prosthesis must be considered. Late infections often have a painless period. Fever patients are less than 50%, and only 10% of patients have leukocytosis in the surrounding blood. It is more difficult to develop painless artificial joint infections caused by Staphylococcus epidermidis. Prosthesis loosening identification must be confirmed by X-ray and other tests.
1. In the case of early infection, the body temperature not only does not recover after 3 days of operation, but the joint pain is not only gradually reduced, but gradually aggravated, there is jumping pain at rest, abnormal infiltration or secretion, and should be Careful examination, do not easily attribute the fever to the infection of other parts such as the postoperative lung or urinary system, and do not simply consider the incision exudate as a common oozing such as fat liquefaction, but also identify the infection is located Superficial organization, still deep and around the prosthesis.
2. Most patients with advanced infection have left the hospital. The joints are swollen, painful, and fever may not be serious. Half of the patients may have no fever. Staphylococcus epidermidis can cause painless infection. Only 10% of patients have increased white blood cell count and elevated erythrocyte sedimentation rate. More common, but not specific, sometimes misdiagnosed pain as loosening of the prosthesis, the latter's pain is related to exercise, should be relieved at rest, and inflammatory pain, not relieved during rest, but some people think that the main loosening of the prosthesis The reason is a chronic infection.
Early infection, no abnormal manifestations on X-ray, may have positive performance after weeks or months, similar to late infection, showing a bright band between bone and bone cement, thinning of cortical margin, periosteal reaction is lamellar, bone The density increasing zone and the translucent zone coexist.
Examine
Examination of joint infection after artificial joint replacement
Diagnostic puncture of tissue or synovial fluid culture joints is necessary. Tissue or synovial fluid culture must be strictly sterile, usually in the operating room. If the routine culture is negative and highly suspected of infection, special Culture techniques require complex nutrients for the growth of anaerobic bacteria.
1. X-ray examination: ordinary X-rays should be reflected after weeks or months of infection. X-ray translucent bands are formed between bone and bone cement. The cortical margins are thinned. The periosteal reaction is lamellar and the bone density increases. Zones and translucent zones coexist and must be compared with previous X-rays to identify early changes.
Intra-articular angiography can show the contour of the joint cavity, as well as the location and extent of the infection. If the sinus has reached the surface of the skin, it can be used for sinus angiography to assist in diagnosis.
2. Radionuclide scintigraphy: As with septic arthritis, uptake of 99mTc and 67ca citrate can help diagnose, but 99mTc is not specific, while 67ca citrate is only moderately specific.
Diagnosis
Diagnosis and diagnosis of joint infection after artificial joint replacement
diagnosis
Diagnostic joint puncture is very important, bacterial culture should pay attention to strict operation, do not pollute, if the culture is negative and highly suspected of infection, the culture method should be changed.
Differential diagnosis
Painless artificial joint infections caused by Staphylococcus epidermidis are more difficult to identify with loosening of the prosthesis and must be confirmed by X-ray and other tests.
