Despite several preventive strategies, periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) is still a devastating complication. Early diagnosis and appropriate treatment are crucial to achieve successful infection control, but challenging since there is no test with 100% sensitivity and 100%. Therefore, several national and international guidelines include synovial analysis of joint aspirates as important diagnostic criteria, but cut-off levels for synovial cell count (CC) and polymorphonuclear (granulocyte) percentage (PMN%) are still debatable. The current investigation was performed to analyze the overall accuracy and optimal cut-off of synovial CC and PMN% following total knee (TKA) and total hip arthroplasty (THA). Between October 2012 and June 2017, all patients with painful TKA or THA, who underwent joint aspiration before revision arthroplasty were included in this retrospective study. From aspirated synovial fluid, leukocyte esterase activity, leukocyte CC and PMN% were determined, and specimens were sent for bacterial culture. A total of 524 preoperative joint aspirations (255 hips, 269 knees) were enrolled for final analysis. For 337 patients, the synovial CC and PMN% could be measured by the laboratory. From those patients, 203 patients were scheduled for aseptic revision, and 134 patients for septic revision arthroplasty according to the MSIS criteria for PJI. Specificity (SP), sensitivity (SE), positive predictive value (PPV), negative predictive and overall accuracy were measured for CC and PMN%. The optimum cut-off value was calculated by the ROC and the value giving the AUC, achieving the best possible level of sensitivity and specificity.Introduction
Methods
Alpha-defensin was recently introduced as a new biomarker having a very high accuracy to rule out periprosthetic joint infection (PJI). A new rapid lateral flow version of the Alpha-defensin test was developed and introduced to detect high levels of Alpha-defensin in synovial fluid quickly and with ease. We conducted a single-centre prospective clinical study to compare the results of the Alpha-defensin rapid test* against the conventional diagnostics according to MSIS criteria. A total of 223 consecutive patients with painful total hip or knee arthroplasty were enrolled into the study. In all patients, blood C-reactive protein was measured and joint aspirations were performed. From the synovial fluid a leukocyte cell count with granulocyte percentage, microbiology cultures and Leukocyte Esterase tests were carried out according to the recommendation of MSIS for diagnosing PJI. At the same time, the Lateral Flow Test* was performed from the aspirate. 191 subjects with 195 joint aspirations (96 hips, 99 knees) were included in final clinical and statistical evaluation. We had 119 joints with an aseptic revision and 76 joints with PJI.Aim
Method
A key of success in the treatment of prosthetic joint infection (PJI) is the proper diagnosis. There is a lack of diagnostic tools able to diagnose a PJI with high accuracy. Alpha-defensin has been proposed as possible solution but the available literature is still limited. This prospective study was carried out in order to determine (1) what is the sensitivity, the specificity, the positive and the negative predictive value of the Alpha-defensin immunoassay test in diagnosing PJI; (2) which clinical features may be responsible for false positive and false negative results? Preoperative aspiration was performed in patients presenting with a painful hip/knee arthroplasty. Metallosis, other inflammatory comorbidities and previous/concomitant antibiotic therapy were not considered as exclusion criteria. Patients with inadequate amount of synovial fluid for culture were excluded. At time of revision synovial fluid samples were taken in the OR in order to perform Alpha-defensin assay. During surgical debridement tissue samples for cultures were obtained. Prospectively, 156 patients (65 knees and 91 hips) were included. A diagnosis of PJI was confirmed in 29 patients.Aim
Method
Cement restrictors are used for maintaining good filling and pressurization of bone cement during hip and knee arthroplasties. The limitations of certain cement restrictors include the inability to accommodate for large medullary canals particularly in revision procedures. We describe a technique using SurgicelTM (Johnson & Johnson) and SPONGOSTAN™ (Johnson & Johnson) (Fig 1) to form a cement restrictor that can accommodate for large canal diameters and provide excellent pressurisation. The technique involves the application of SPONGOSTAN™ (Johnson & Johnson) foam onto a SurgicelTM (Johnson & Johnson) mesh which is then rolled onto the SPONGOSTAN™ foam forming a uniform cylindrical structure Figs 2,3. The diameter of the restrictor can be adjusted according to the desired femoral canal diameter through increasing the thickness of the SPONGOSTAN™ (Johnson & Johnson) foam. The restrictor is then inserted into the desired position in the medullary canal where it expands uniformly creating an effective restrictor and bone plug Fig 4. Bone cement is then applied and pressurisation commenced prior to the insertion of the implant Fig5. SPONGOSTAN™ is an absorbable haemostatic sponge intended for haemostatic use by applying to a bleeding surface. It consists of a sterile, water-insoluble, malleable, porcine gelatin absorbable sponge. Surgicel ™ is an absorbable hemostatic agent composed of oxidized regenerated cellulose. It is a sterile, absorbable knitted fabric that is flexible and adheres readily to bleeding surfaces. Both products are routinely used for their haemostatic properties in various surgical disciplines.Background
Technique
In the past orthopaedic surgeons have kept their hands off from spontaneous or artificial fused hips, because those hips were painless, and the result of any further surgical procedure would be doubtful. In our days the need for conversion hip arthroplasty became a demand of patients having a better quality of life. In this paper we report on our results and the perioperative complications following conversion surgery. Between 1993 and 2002 thirty-one hips of twentyfive patients (18 males, 7 females) were converted from totally stiff hip to total hip arthroplasty in the two most frequented orthopaedic hospitals in Budapest, Hungary (Semmelweis University, Medical School, Dept. of Orthopaedics &
Hospital of Hospitaller Brothers of St.John of God, Dept. of Orthopaedics). The mean age of the patients was 47.2 years (ranging from 14 to 75 years) at the time of surgery. The average follow up was 50.7 months (2–176). At our 25 patients the hips became stiff 15.7 years ago as an average (3–61). Spontaneous fusion occured in 14 cases due to Bechterews disease (spondylitis ankylopoetica). In 4 cases fused hips were converted following arthrodesis procedures. There was no significant difference between each groups, spontaneous ankylosis and surgical fusion were similar, they were evaluated as stiff hips on the same way. The indication for surgery was in most cases a painful lumbar spine or osteoarthritic knee joint on the ipsilateral side. The surrounding joints are obviously overloaded and overused because of the stiff hip joint, even though if the hip is painless. 27 cemented and 4 uncemented hip prostheses were implanted. The mean duration of conversion arthroplasties was 110 minutes, the perioperative blood loss was 1019 ml. Additional surgical procedures may be used, like intertrochanteric wedge resection, osteotomy of greater trochanter, muscle release from the iliac bone, tenotomy of the hip adductors or knee flexors. The Harris Hip Score increased significantly from 34.2 to 81.3 (p<
0.01). The leg length discrepancy decreased from 4.0 cm to 1.2 cm, the difference of thigh circumference changed from 4.3 cm to 2.7 cm, all results as an average. Trendelenburgs gait was detected at 25 hips pre-op, and at 5 hips at the time of follow up. Five cases were reoperated due to haematoma formation, there was one prosthesis disclocation and one early septic complication. Based upon the good clinical results at the follow up, we recommend to change the orthopaedic surgeons’ mind considering conversion arthroplasties. The surgical procedure can be performed securely, but it is technically challenging for each surgeon. The intraoperative use of fluoroscopy and preoperative planning are mandatory in conversion arthroplasty. Conversion arthroplasty is performed prior to severe degenerative changes in the surrounding joints.
