Mechanical failure due to dislocation, fracture and acetabular wear as well as persistence of infection are the main complications associated with the use of hip spacers in the treatment of periprosthetic joint infections (PJI). We have developed a novel, custom-made spacer as part of two-stage septic hip replacement and present the two- to five-year results after reimplantation. We prospectively examined a total of 73 patients over our study period in whom our new spacer technique was used. The technique includes a dual mobility inlay and a cemented straight stem in combination with antibiotic-loaded PMMA bone cement which allows full weight bearing meanwhile the interim period. The follow-up ranged between 24 and 60 months after reimplantation as second stage of a two-stage approach. The patients were contacted as part of the follow-up using a questionnaire concerning reoperation, reinfection as well as hip function by using the Harris Hip Score. 72 patients (98,6%) could be reimplanted, one patient is still using the spacer prothesis for 45 months because of excellent functional results with a Harris Hip Score of 95, nevertheless reimplantation is planned. The reinfection rate was less than 7% after reimplantation. The dislocation rate was 5%, and in total there was an overall complication rate of less than 10%. The Harris Hip Score was significantly improved. The ENDO spacer surgical technique is a promising option in the treatment of periprosthetic joint infections (PJI) for two-stage septic exchange with a low dislocation rate and good infection control after reimplantation. In addition, it enables early mobilization with the possibility of full weight-bearing in the interval between spacer implantation and reimplantation.
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
Mechanical wear and corrosion at the head-stem junction of total hip arthroplasties (THAs) (trunnionosis) have been implicated in their early revision, most commonly in metal-on-metal (MOM) hips. We can isolate the role of the head-stem junction as the predominant source of metal release by investigating non-MOM hips; this can help to identify clinically significant volumes of material loss and corrosion from these surfaces. In this study we examined a series of 94 retrieved metal-on-polyethylene (MOP) hips for evidence of corrosion and material loss at the taper junction using a well published visual grading method and an established roundness-measuring machine protocol. Hips were retrieved from 74 male and 20 female patients with a median age of 57 years (30 to 76) and a median time to revision of 215 months (2 to 324). The reasons for revision were loosening of both the acetabular component and the stem (n = 29), loosening of the acetabular component (n = 58) and infection (n = 7). No adverse tissue reactions were reported by the revision surgeons.Objectives
Methods
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
