Clinical analysis of infection after artificial hip arthroplasty
Abstract】Objective To investigate the treatment of periprosthetic infection after artificial hip arthroplasty. Methods The clinical data of 15 patients with post-arthroplasty infection were retrospectively analyzed from 2008 to 2011. 1 case was treated by simple joint debridement, 2 cases by stage I revision surgery, and 12 cases by stage II revision surgery. At the time of final follow-up, no recurrence of infection was observed in any of the 11 patients. The mean improvement in hip Harris score was 36.5 points in patients who underwent revision of the hip joint. Conclusion Depending on the type of infection and the general condition of the patient, debridement or total hip revision surgery can remove the infected lesions and maximize the joint function of the patient.
【Key words】Hip replacement; infection; revision
Deep infection after artificial hip arthroplasty is a catastrophic complication of artificial hip arthroplasty, which often leads to complete failure of the joint replacement, resulting in disability or even death of the patient, and even if remedy and treatment are obtained, it will bring heavy economic burden and mental stress to the patient. Therefore, how to make timely and correct judgment and treatment of artificial joint infection is still an important issue for clinical orthopaedic surgeons. From 2008 to 2011, 15 patients with post-arthroplasty infection were treated in our department, and we summarized the lessons learned in the process of diagnosis and treatment to provide some experience for the treatment of post-arthroplasty infection.
1. Clinical data
1.1 General data There were 15 cases of infection after artificial total hip arthroplasty in this group, all of them were single hip initial replacement, 5 cases were male and 10 cases were female; age ranged from 48 to 82 years old, average 69 years old. Causes of hip replacement: 4 cases of femoral neck fracture, 7 cases of femoral head necrosis, 3 cases of rheumatoid arthritis and 3 cases of combined diabetes mellitus.
1.2 Examination contents The patients underwent various routine examinations upon admission, including leukocyte classification and count, blood sedimentation and C-reactive protein dynamic test; bilateral hip imaging; joint cavity puncture fluid or drainage fluid culture and drug sensitivity test; intraoperative microbiological examination of the fluid around the prosthesis and determination of the integrity of the deep fascia and the presence of sinus tract formation and edema, and multiple sampling of the boundary membrane tissue around the prosthesis Pathological section for observation.
1.3 Preserve the prosthesis for debridement Expose along the original incision to the prosthesis, thoroughly remove intra-articular infection and suspected infection, preserve the prosthesis, rinse thoroughly with hydrogen peroxide and 0.1% iodophor after soaking with pulses, and place the tube. Systemic antibiotic treatment and joint placement flushing were performed for 3-4 weeks based on bacterial culture and drug sensitivity results.
1.4 Revision treatment Expose along the original incision to the prosthesis and remove the femoral stalk and socket cup sequentially after dislocation. The incision scar, sinus tract and surrounding tissues, edema and periarticular inflammatory tissues were excised; bone cement and pseudomembranous tissues were removed, and the hip joint was flushed with plenty of saline, hydrogen peroxide, 0.1% iodine soaked and then pulsed and thoroughly flushed. temporary fixation was performed when a fracture of the femur was present.
2. Results
All patients in this group had preoperative pain and limitation of movement in the affected limb, and preoperative C-reactive protein was persistently elevated, and blood sedimentation and white blood cell count were elevated in 8 cases and 5 cases, respectively. The culture was positive in 11 cases, including 9 cases of Staphylococcus aureus, 1 case of Staphylococcus epidermidis, and 1 case of Escherichia coli; sinus tract formation was found in 3 cases intraoperatively; pathological sections were examined for inflammatory tissue in 15 cases, and the diagnosis of periprosthetic infection was clear with the above examination results. Treatment: 1 case of prosthesis preservation, 2 cases of stage I revision and 12 cases of stage II revision. All 15 cases in this group were followed up for an average of 25 months (9-48 months), and no recurrence of infection was seen in any of the 15 patients at the last follow-up. The Harris score of the hip joint improved from an average of 45.3 points before surgery to an average of 81.8 points after surgery, with an average improvement of 36.5 points.
3. Discussion
Six conditions are required for the examination and evaluation of infection after artificial hip arthroplasty: history and clinical data, laboratory tests, imaging data, intraoperative findings, microbiological data, and histological examination. The presence of systemic infection, rheumatoid arthritis, diabetes mellitus, obesity, previous history of tuberculosis or pulmonary infection, long-term oral hormone administration and other systemic factors, as well as a history of local trauma and surgery are high-risk factors for postoperative infection. Reactive protein can reflect inflammation earlier and faster, and dynamic observation in combination with blood sedimentation can improve the specificity and sensitivity of diagnosis, especially in the detection of joint puncture fluid. CT or MRI can visualize joint exudate, sinus tracts and soft tissue abscesses, which can help in the diagnosis of infection after hip replacement. Prosthetic loosening. It is generally accepted that a diagnosis of deep infection after artificial hip arthroplasty is made when at least one of the following conditions is present in the clinic.
① There is a chronic sinus tract communicating with the joint cavity.
②ESR>4Omm/h and CRP>20mg/l;
③Pus was found on intraoperative probing;
④ intraoperative frozen section with polymorphonuclear leukocytes >5/high magnification field.
The fundamental purpose of treatment of deep infection after artificial hip replacement is to remove infection, relieve pain and preserve joint function as much as possible, including: clearing and preserving the prosthesis, performing revision surgery in one or two stages, and supplementing with adequate antibiotic treatment. The infection around the prosthesis after artificial joint surgery in China is dominated by G+ bacteria, and most of them are Staphylococcus aureus and Staphylococcus epidermidis, which is also consistent with the results of our bacterial culture, which can adhere to the surface of the prosthesis or bone cement, forming a biofilm to resist the body’s defense mechanism and grow and spread. Our experience is to switch to oral antibiotics after 2 weeks of postoperative sedation of sensitive antibiotics, and to stop oral antibiotics after normalization of dynamic blood sedimentation and C-reactive protein, which usually lasts for 3-8 weeks. The prerequisite for taking debridement to retain the prosthesis for treatment is that the prosthesis is stable and acutely infected (within 4 weeks postoperatively), the infecting organism is clear, the bacterial virulence is low and sensitive antibiotics are available, and the lining can be replaced during debridement.
Phase I revision has the advantage of light wound scarring and joint stiffness, is conducive to the recovery of postoperative joint function, is suitable for clear pathogenic bacteria, sensitive to antibiotics, no refractory pathogens (such as enterococci,
It is suitable for those who have clear pathogenic bacteria, are sensitive to antibiotics, have no refractory pathogens (e.g. enterococci, methicillin-resistant Staphylococcus aureus), can use antibiotic bone cement and cannot tolerate surgery. The use of antibiotic bone cement with exact removal of inflammatory tissue and bone cement debris is the key to successful revision in phase I. It is generally believed that the compressive strength of antibiotic loaded with Q1g per 40g of bone cement is not significantly different from that of ordinary bone cement. In this group, two patients could not tolerate the secondary surgery due to their poor general condition, and chose to implant the bone cement prosthesis for fixation directly after thorough debridement (40 g of bone cement with 1 g of vancomycin). In order to thoroughly remove the boundary membrane between the prosthesis and the bone interface, we used a grinding drill to uniformly grind away the bone about 1 mm thick in the medullary cavity, and pulsed and thoroughly flushed it after soaking it with hydrogen peroxide and 0.1% iodine. Postoperatively, we did not recommend joint lavage because of the possibility of “short circuiting” of the channels and the increased chance of infection.
Phase II revision mainly consists of surgical removal of the original prosthesis, removing inflammatory tissues as thoroughly as possible, and then after a period of inactivity and after the inflammation has been controlled, total hip replacement surgery is performed in phase II. acrylic
The widespread use of PROSTALAC (prosthesis of antibiotic-loaded acrylic cement) allows the affected joint to move, overcoming the disadvantages of limb shortening, soft tissue contracture, and bone loss, but the interval of protraction is still controversial. Theoretically, the antibiotic-containing cemented prosthesis can better control infection and prevent recurrence, but clinically, it has not achieved better results than the common cemented and biological prosthesis, and the hybrid prosthesis (biologic socket and cemented stem), which is currently promoted in the academic field of artificial joints, can achieve relatively ideal treatment results. In this group, prosthesis-like bone cement was used as a spacer after debridement, and patients were encouraged to move early. The timing of phase II joint replacement was mostly performed when the blood sedimentation and C-reactive protein decreased to normal range 6-8 weeks after debridement.
4.Summary
Although aseptic operation is an important measure to prevent infection after total hip arthroplasty, the initial stability of the prosthesis should be emphasized to ensure the longitudinal stability and lateral rotational stability of the prosthesis, especially for non-cemented femoral stems. If the initial stability of the prosthesis is good, even if there are infection factors, the infection will be limited or eliminated. The treatment of deep infection after THR is still a controversial problem and should be considered in the context of the patient’s general condition, pathogenic characteristics and surgical conditions in order to find an optimal treatment plan. In our opinion, once the infection after joint replacement is clearly established, stage II revision is recommended and is safer.