Management of infected total knee arthroplasties

In a prospective study of 14 consecutive infected total knee arthroplasties ( TKAs ) treated through 1979, the management consisted of: (1) 11 delayed exchange arthroplasties, with 2 failures requiring above-knee amputation; (2) 2 in situ debridements; and (3) 1 arthrodesis. The final outcome of the delayed exchange arthroplasty group regarding joint pain, patient function, and joint performance was (a) inferior to that of primary TKA (before infection), (b) better than that of resection arthroplasty, and (c) worse than that of a control group of non-infected TKAs respectively. Debridement without prosthesis resection was successful only in cases of immediate postoperative infection (2 successes in 4 TKAs ) and uniformly unsuccessful in infections occurring beyond the perioperative period (4 failures in 4 TKAs ). The study indicates that delayed exchange total knee arthroplasty is a reasonable alternative to arthrodesis following resection of an infected TKA and can be performed without undue risk of recurrent infection.     

Revision of infected knee arthroplasty

Sixteen infected knee arthroplasties were revised and followed for 5 (1-10) years. There were nine recurrences of infections, but in one of these a second revision was successfully carried out. The remaining seven revisions resulted in only four functioning prostheses. The results were poor for hinged and stabilized prostheses for which arthrodesis, after eradication of the infection, is recommended. Infected compartmental prostheses with good bone stock could be treated with a two-stage procedure using tricompartmental revision prostheses.     

Revision of infected knee arthroplasty

Sixteen infected knee arthroplasties were revised and followed for 5 (1-10) years. There were nine recurrences of infections, but in one of these a second revision was successfully carried out. The remaining seven revisions resulted in only four functioning prostheses. The results were poor for hinged and stabilized prostheses for which arthrodesis, after eradication of the infection, is recommended. Infected compartmental prostheses with good bone stock could be treated with a two-stage procedure using tricompartmental revision prostheses.     

Revision of infected knee arthroplasty

Sixteen infected knee arthroplasties were revised and followed for 5 (1–10) years. There were nine recurrences of infections, but in one of these a second revision was successfully carried out. The remaining seven revisions resulted in only four functioning prostheses. The results were poor for hinged and stabilized prostheses for which arthrodesis, after eradication of the infection, is recommended. Infected compartmental prostheses with good bone stock could be treated with a two-stage procedure using tricompartmental revision prostheses.     

Revision interventions in aseptic and infected loose knee endoprostheses

From 1984 to 1988 20 revisions for aseptic or septic loosening of knee prosthesis were performed. In 12 case there was an aseptic- and in 8 cases a septic loosening of the prosthesis. Most revision surgery for loosening of knee replacement needs reconstruction of bone stock. In loosening of unconstrained knee prostheses (uni-, totalcondylar knees) it was possible to insert a total condylar knee for revision surgery. Partially gross deviations had to be corrected, but in all cases a good alignment and ligamentous stability were effected. In septic loosening we had good experience with the two stage procedure. We temporarily implanted a gentamycine-PMMA-Spacer to avoid soft tissue contracture and to inhibit fusion of the cancellous bone. Arthodesis after knee replacement is difficult to manage, because the sclerotic bone of the site the prosthesis doesn't easily fuse.     

Presence of medical comorbidities in patients with infected primary hip or knee arthroplasties

Many older patients undergoing primary hip or knee joint arthroplasty surgery have multiple medical problems. In this retrospective case-control study, the authors examined the individual and cumulative effects of various types of medical comorbidities on the risk of developing prosthetic joint infection after surgery. Case and control patients were matched by age, sex, and procedure. Analysis was undertaken using crude odds ratios (ORs) and multiple logistic regression analysis. Fifty-one patients with 52 joint infections were identified. Both diabetes mellitus (OR, 3.91; P = .04) and total number of medical conditions (OR, 1.35; P = .005) were associated with higher risk of infection. This information allows the orthopedic surgeon to inform patients more fully regarding the risks of surgery, and promotes the reduction and optimization of medical comorbidities before surgery.     

Revision operations on infected total hip arthroplasties. Two- to nine-year follow-up study

One hundred two of 110 infected hip arthroplasties revised with the protection of gentamicin-loaded cement were followed for a minimum of two years. In 77 of 102 hips the infection healed after one revision operation and in five of eight hips after a second revision operation, representing a final healing rate of 80%. No significant difference in healing rate could be demonstrated with regard to individual bacterial species. However, in infections with a mixed flora, the healing rate was only 27% (p less than .01). After an average of six years, 33 of 82 healed hips had signs of roentgenographic loosening, nine of which had been revised. The modified Merle d'Aubigne and Postel score averaged 5.3 for pain, 3.7 for walking ability, and 4.0 for range of motion (ROM) in patients with healed infections.     

The use of an articulating spacer in the management of infected total knee arthroplasties

Eleven infected total knee arthroplasties underwent revision using an articulating spacer comprising a total condylar component and meniscal polyethylene insert cemented in place using antibiotic-loaded cement. Only 1 case required subsequent rerevision for infection, 2 were revised for pain, 6 remain in situ, and 2 patients have died with their spacers in situ. Average Knee Society clinical rating for the spacers left implanted is 167 at an average of 65 months. This articulating spacer appears not to require mandatory second-stage surgery, although should this prove necessary, then it is relatively straightforward to perform.     

Immune-inflammatory response in infected arthroplasties

We studied the immunocytology of synovial fluid in purulent endoprosthetic infections using cell subtype-specific monoclonal antibodies in avidin-biotin-peroxidase complex staining. Two thirds of the monocytes were CD15-positive, whereas CD2-positive T lymphocytes only formed one third of all the mononuclear cells. The synovial fluid monocyte-activated T-cell ratio differed from findings in sterile inflammatory, reactive and rheumatoid arthritis.     

Infected total knee arthroplasties

Thirty infected total knee arthroplasties were investigated in 29 patients over an average interval of 42 months. Eleven infections began in the immediate perioperative period. Six developed from postoperative wound-healing problems. The remainder were late infections. Staphylococcus was found in 16 infections, gram-negative agents in five, mixed organisms in five, and other gram-positives in four. Sixteen knees were arthrodesed, six knees were treated by retention of the components, and two above-knee amputations and one resection arthroplasty were performed. Five patients had two-stage revisions to new components. Evidence of persistent infection was present in three arthrodeses, two retained arthroplasties, and one knee that was revised. Perioperative infections were associated with staphylococcal organisms and responded less favorably to conservative treatment. The failure of primary wound healing demands immediate measures to obtain skin coverage. Retention of the arthroplasty components is possible only in selected patients.     

Cemented total knee arthroplasties

INTRODUCTION: The aseptic loosening of cemented total knee arthroplasties is still an unsolved problem. In this regard, the hydrolysis resistance in the metal-to-bone cement interface is of major importance. MATERIAL AND METHODS: Cemented pre-treated tibia components coated by means of a silica/silane interlayer system of the model "Columbus PS" were dynamically loaded with the help of a knee-simulator similar to DIN ISO 14243. After loading, the components were microscopically analysed concerning debonding in the metal-to-bone cement interface as well as with regard to cement mantle defects. These data were matched with uncoated "Columbus PS" components. Unloaded coated and uncoated tibia components acted as a control. RESULTS: In comparison with uncoated tibia components, the pre-treated and coated ones yielded a highly significant reduction of cement defects (p < 0.01) as well as a significant reduction of debonding in the metal-to-bone cement interface (p < 0.05). CONCLUSION: By means of the silica/silane interlayer system for cemented tibia components, a hydrolytic debonding in the metal-to-bone cement interface with subsequent mechanical loosening and consecutive early cement mantle failure can be significantly reduced. This could lead to an increased long-term stability of the metal-to-bone cement compound with decreased aseptic loosening in clinical use.     

Ankle arthroplasties generate wear particles similar to knee arthroplasties

Second-generation total ankle arthroplasties have encouraging medium-term results, but the wear of the joint materials is of concern. The aim of the current study was to examine and compare the size, shape, and concentration of polyethylene particles in synovial fluid with total ankle arthroplasties and established posterior-stabilized total knee arthroplasties. Synovial fluid was obtained from 15 patients with well-functioning total ankle arthroplasties and 11 patients with posterior-stabilized total knee arthroplasties at least 6 months after surgery. Polyethylene particles were isolated and analyzed using scanning electron microscopy. Particle size (equivalent circle diameter) in ankles was 0.81 +/- 0.09 microm (mean +/- standard error) and in knees was 0.78 +/- 0.08 microm. Particle shape (aspect ratio) in ankles was 1.57 +/- 0.04 and in knees was 2.30 +/- 0.22. The particle concentration was 1.02 +/- 0.43 x 10/mL in ankles and 1.13 +/- 0.56 x 10/mL in knees, and the particle concentration and size in total ankle arthroplasties were similar to those in total knee arthroplasties. Total ankle arthroplasties generated significantly rounder particles than total knee arthroplasties. These data suggest that the long-term result of total ankle arthroplasty should be as good as posterior-stabilized total knee arthroplasties in terms of polyethylene wear and the prevalence of osteolysis.     

Reinfusion of whole blood after revision surgery for infected total hip and knee arthroplasties

Because of its proven effectiveness in reducing the need for banked blood transfusions following total joint arthroplasty, the indications for postoperative blood retrieval were expanded to include seven cases of infected total knee or hip arthroplasties where a one-stage exchange procedure was performed. Each joint had been aspirated after surgery and had positive cultures but no gross pus at the time of revision surgery. Each of the operations included debridement with reimplantation of a cementless prosthesis under cover of intravenous antibiotics for 48 hours followed by oral treatment until discharge. Antibiotic-soaked morselized bone graft was used in all patients to restore deficient nonstructural bone. Wound drainage blood was retrieved and reinfused during the first 8 hours after surgery, averaging 958 cc. Banked blood usage averaged 2.4 U (88% homologous) with an average blood loss of 1,974 cc. One patient experienced shaking chills during a second reinfusion of 600 cc of blood without stoppage of the transfusion. Wound hematoma occurred in one patient but did not require surgical evacuation. No patient developed evidence of septicemia.     

The value of indium 111 leukocyte scanning in the evaluation of painful or infected total knee arthroplasties

Evaluation of painful total knee arthroplasties (TKAs) for infection can be difficult. Indium 111 (111In) leukocyte bone scanning provides a minimally invasive technique for evaluation of possible infection. Thirty-eight patients with a painful TKA who had surgical exploration after 111In leukocyte scanning were reviewed. The scan had an accuracy of 84%, a sensitivity of 83%, and a specificity of 85%. The 111In leukocyte scans must be interpreted in conjunction with the clinical evaluation of the patient because they are less accurate for study of TKAs than of total hip arthroplasties.     

Staged bilateral hip or knee arthroplasties

PURPOSE: To compare the operating time, amount of blood transfused, length of hospital stay, and early complications (within 6 months) between 2-week staged bilateral arthroplasties and matched randomised controls undergoing unilateral arthroplasties. METHODS: From October 1992 to October 2000, 90 patients who underwent bilateral hip or knee arthroplasties with a 2-week interval were compared with matched randomised controls undergoing unilateral arthroplasties. A single surgeon performed all procedures. RESULTS: After the match-up process, 30 pairs of patients were included in the analysis. There were no significant differences in the operating times, amount of blood transfused, and early complication rates. The mean difference in length of hospital stay was significant (t=-3.552, df=29, p<0.001). CONCLUSION: Compared to staged procedures with an interval months apart, staged sequential arthroplasty with a 7- to 10-day interval during one hospital admission is more efficient, as it facilitates earlier rehabilitation without higher complication rates, and entails shorter hospital stays.     

Survival of knee arthroplasties for rheumatoid arthritis

During a 15-year period, 498 primary knee arthroplasties for chronic rheumatoid and related arthritides were performed. Ninety arthroplasties where prosthetic components were added, removed or replaced were recorded as failures. Eighty-one revisions were exchange arthroplasties, eight attempted arthrodeses and one an above-the-knee amputation. Survival rates were calculated with a life table technique. The cumulative 5-year survival rate was 76 per cent for tibial hemiprostheses, 78 per cent for unicompartment prostheses, 100 per cent for tricompartment prostheses, 87 per cent for stabilized prostheses and 84 per cent for hinge prostheses. Continuous deterioration was observed in the tibial hemiprostheses. The improved surgical technique, with guide instruments and release procedures for better alignment and stability, and to some extent the improved prosthetic design may explain the good early results with tricompartment prostheses.     

Survival of knee arthroplasties for rheumatoid arthritis

During a 15-year period, 498 primary knee arthroplasties for chronic rheumatoid and related arthritides were performed. Ninety arthroplasties where prosthetic components were added, removed or replaced were recorded as failures. Eighty-one revisions were exchange arthroplasties, eight attempted arthrodeses and one an above-the-knee amputation. Survival rates were calculated with a life table technique. The cumulative 5-year survival rate was 76 per cent for tibial hemiprostheses, 78 per cent for unicompartment prostheses, 100 per cent for tricompartment prostheses, 87 per cent for stabilized prostheses and 84 per cent for hinge prostheses. Continuous deterioration was observed in the tibial hemiprostheses. The improved surgical technique, with guide instruments and release procedures for better alignment and stability, and to some extent the improved prosthetic design may explain the good early results with tricompartment prostheses.     

Periprosthetic fractures in patients with total knee arthroplasties

Ten patients with total knee arthroplasties sustained periprosthetic fractures. Nine of these were supracondylar fractures, and one occurred in the middle one-third of the tibia. These patients were treated with conservative methods in two cases and internal fixation with plate and screws in three cases. The remaining five patients were treated with intramedullary fixation using a specially designed revision prosthesis with long intramedullary stems. The best results wer achieved through the revision arthroplasty, based on walking ability, range of motion, and early rehabilitation.     

Survival of knee arthroplasties for rheumatoid arthritis

During a 15-year period, 498 primary knee arthroplasties for chronic rheumatoid and related arthritides were performed. Ninety arthroplasties where prosthetic components were added, removed or replaced were recorded as failures. Eighty-one revisions were exchange arthroplasties, eight attempted arthrodeses and one an above-the-knee amputation. Survival rates were calculated with a life table technique. The cumulative 5-year survival rate was 76 per cent for tibial hemiprostheses, 78 per cent for unicompartment prostheses, 100 per cent for tricompartment prostheses, 87 per cent for stabilized prostheses and 84 per cent for hinge prostheses. Continuous deterioration was observed in the tibial hemiprostheses. The improved surgical technique, with guide instruments and release procedures for better alignment and stability, and to some extent the improved prosthetic design may explain the good early results with tricompartment prostheses.