Is there a role of calprotectin testing in the diagnosis of surgical site infections after total hip and knee arthroplasty? A preliminary study.

BACKGROUND: Recent studies have revealed the usefulness of synovial calprotectin (CLP) in diagnosing chronic periprosthetic joint infections (PJIs). However, there is still a lack of evidence to support the use of serum CLP in the diagnosis of early PJIs and surgical site infections (SSIs) after total joint arthroplasties (TJAs). OBJECTIVES: The primary aim of this study is to investigate the standard kinetics of CLP concentrations in the blood during the very early postoperative period after non-complicated total hip arthroplasty (THA) and total knee arthroplasty (TKA). The secondary aim was to perform a preliminary comparison of CLP concentrations between non-infected patients and patients with recognized SSIs. MATERIAL AND METHODS: A total of 64 consecutive patients who underwent primary THA and TKA were included in this prospective research. Sixty patients (30 THA and 30 TKA) were scheduled to determine the standard shape of the blood CLP curve and the expected concentrations during the first 5 postoperative days after non-complicated TJAs. In 4 additonal patients, early SSI was confirmed, and they were included in a separate SSI subgroup. RESULTS: Calprotectin demonstrated a linear increase during the first 5 postoperative days. Statistically significant differences in CLP concentrations between non-infected cases and SSIs were not observed. The preoperative median results with interquartile range (Q1-Q3) were 0.52 (0.39-0.64) mg/dL and 0.5 (0.47-0.52) mg/dL (p = 0.77), while post operation they were as follows: on postoperative day 1: 0.88 (0.53-1.3) mg/dL and 0.86 (0.62-1.1) mg/dL (p = 0.84), on postoperative day 3: 1.77 (1.29-2.08) mg/dL and 1.85 (1.70-1.95) mg/dL (p = 0.72), and on postoperative day 5: 2.32 (1.79-2.67) mg/dL and 2.56 (2.25-2.83) mg/dL (p = 0.55), respectively. CONCLUSION: Serial CLP measurements during the early postoperative period revealed a linear (statistically significant) increase in concentration to postoperative day 5 without an evident point of decrease. A significant difference in median values and the course of curve patterns between the non-complicated and SSI groups was not observed.

The Diagnostic Utility of Fast Tests for Detecting C-Reactive Protein in Synovial Fluid in Periprosthetic Joint Infections.

BACKGROUND: Despite the fact that many synovial fluid biomarkers have found application in the routine diagnosis of periprosthetic joint infection (PJI), this process still remains a challenge for orthopaedic surgeons. To simplify this process, fast point-of-care (POC) tests can be used during ambulatory visits and in operating room conditions. However, before such tests can be routinely used in clinical practice, they require validation. The purpose of the present study was to evaluate the diagnostic accuracy of different fast POC tests for detecting C-reactive protein (CRP) in synovial fluid for the diagnosis of PJI. METHODS: Synovial fluid samples were collected from 120 consecutive patients who underwent revision total joint arthroplasty (TJA). The patients were divided into 2 groups. The first group included 76 patients who underwent revision for reasons other than infection (the aseptic revision TJA [arTJA] group), and the second group included 44 patients who underwent revision because of periprosthetic joint infection (PJI). The diagnosis of infection was made according to the International Consensus Meeting (ICM) 2018 criteria. All patients were operatively treated at a single orthopaedic center from January 2022 to February 2023. Four fast CRP tests with different cutoff values (1 and 3 mg/L, ≥8 mg/L, ≥10 mg/L [cassette], ≥10 mg/L [strip]) were used off-label for synovial fluid testing. Tests were performed on the same synovial fluid samples, and the results of these tests were compared with those obtained with the laboratory method. RESULTS: The cassette test with a minimum cutoff value of ≥8 mg/L demonstrated the best accuracy for the diagnosis of chronic PJI, with a sensitivity and specificity of 90.9% and 90.8%, respectively. For the cassette test with a cutoff value of >3 mg/L, the sensitivity and specificity were 68.2% and 77.6%, respectively. For the tests with a minimum cutoff value of ≥10 mg/L, the sensitivity and specificity were 77.3% and 94.7%, respectively, for the cassette test and 77.3% and 96.1%, respectively, for the strip test. The laboratory method with the statistically calculated threshold (2.7 mg/L) revealed the highest AUC (area under the receiver operating characteristic curve) value (0.95), with 90.9% sensitivity and 94.7% specificity. CONCLUSIONS: The cassette POC test with the minimum cutoff value of ≥8 mg/L had very good accuracy for the diagnosis of chronic PJI. This test had comparable sensitivity and slightly lower specificity in comparison with the laboratory method with the calculated threshold of 2.7 mg/L. LEVEL OF EVIDENCE: Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Automated patellar height assessment on high-resolution radiographs with a novel deep learning-based approach.

BACKGROUND: Artificial intelligence and deep learning have shown promising results in medical imaging and interpreting radiographs. Moreover, medical community shows a gaining interest in automating routine diagnostics issues and orthopedic measurements. AIM: To verify the accuracy of automated patellar height assessment using deep learning-based bone segmentation and detection approach on high resolution radiographs. METHODS: 218 Lateral knee radiographs were included in the analysis. 82 radiographs were utilized for training and 10 other radiographs for validation of a U-Net neural network to achieve required Dice score. 92 other radiographs were used for automatic (U-Net) and manual measurements of the patellar height, quantified by Caton-Deschamps (CD) and Blackburne-Peel (BP) indexes. The detection of required bones regions on high-resolution images was done using a You Only Look Once (YOLO) neural network. The agreement between manual and automatic measurements was calculated using the interclass correlation coefficient (ICC) and the standard error for single measurement (SEM). To check U-Net's generalization the segmentation accuracy on the test set was also calculated. RESULTS: Proximal tibia and patella was segmented with accuracy 95.9% (Dice score) by U-Net neural network on lateral knee subimages automatically detected by the YOLO network (mean Average Precision mAP greater than 0.96). The mean values of CD and BP indexes calculated by orthopedic surgeons (R#1 and R#2) was 0.93 (± 0.19) and 0.89 (± 0.19) for CD and 0.80 (± 0.17) and 0.78 (± 0.17) for BP. Automatic measurements performed by our algorithm for CD and BP indexes were 0.92 (± 0.21) and 0.75 (± 0.19), respectively. Excellent agreement between the orthopedic surgeons' measurements and results of the algorithm has been achieved (ICC > 0.75, SEM < 0.014). CONCLUSION: Automatic patellar height assessment can be achieved on high-resolution radiographs with the required accuracy. Determining patellar end-points and the joint line-fitting to the proximal tibia joint surface allows for accurate CD and BP index calculations. The obtained results indicate that this approach can be valuable tool in a medical practice.

What is the Accuracy of a Rapid Strip Test That Detects D-lactic Acid in Synovial Fluid for the Diagnosis of Periprosthetic Joint Infections?

BACKGROUND: D-lactic acid is a specific marker produced almost exclusively by bacterial species; thus, the appearance of this marker in synovial fluid may indicate periprosthetic joint infection (PJI). Recently, studies have investigated the accuracy of enzyme-linked laboratory tests that detect D-lactic acid in synovial fluid to diagnose PJI. However, to our knowledge, no studies have determined the usefulness of rapid strip tests that detect D-lactic acid in synovial fluid in the diagnosis of PJI. QUESTIONS/PURPOSES: (1) What is the best cutoff value for the rapid D-lactic acid strip test for diagnosing PJI? (2) What are the diagnostic accuracies (sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV]) of the rapid D-lactic acid strip test and two different rapid leukocyte esterase (LE) strip tests? METHODS: This prospective study enrolled 157 patients who underwent revision THA or TKA from May 2021 to February 2022 at a single orthopaedic center. Seventy percent (110 of 157) were eligible for analysis; 10% of these patients (15 of 157) were excluded based on the exclusion criteria (causes of revisions and additional comorbidities that may interfere with the results), and 20% (32 of 157) of the synovial fluid samples could not be tested (dry taps and blood-contaminated samples that could not be centrifuged). We performed the following off-label diagnostic tests on synovial fluid samples collected from all patients: the D-lactic acid strip test (QuantiQuick TM , BioAssay System), two different LE strip tests (10 EA from ARKRAY and BM 10 from BioMaxima). Differently colored strips were marked with symbols (from [-] to [++++] for D-lactic acid and from [-] to [+++] for LE tests) according to the manufacturers' instructions. For the LE tests, results were different for (++), which corresponds to a minimal value of 250 leu/mL for 10 EA and 125 leu/mL for BM 10 tests. The diagnostic standard for the presence or absence of PJI in this study was the International Consensus Meeting (ICM) 2018 criteria; based on these criteria (without the application of an LE test as a minor criterion), all patients were assessed and divided into two groups. Patients who did not meet the criteria for PJI and underwent revision for aseptic loosening, implant malposition, instability, or implant damage were included in the aseptic revision total joint arthroplasty group (68 patients). Patients with a fistula penetrating the joint, those with two positive culture results of the same pathogen, or those with ≥ 6 points according to ICM 2018 minor criteria were enrolled in the PJI group (42 patients). To ascertain the best cutoff value for the rapid D-lactic acid and both LE strip tests for diagnosing PJI, we used collected results, generated a receiver operating characteristic curve, and calculated the Youden index. To determine the accuracies of the diagnostic tests, we calculated their sensitivities, specificities, PPVs, and NPVs against the diagnostic standard (the ICM 2018 criteria). RESULTS: The best cutoff value for D-lactic acid was 22.5 mg/L, which corresponded to a reading of (+) on the test strip. For D-lactic acid, in the diagnosis of PJI, the sensitivity was 83% (95% confidence interval [CI] 68% to 92%) and specificity was 100% (95% CI 93% to 100%). For both LE strip tests, the best cutoff value was the same as that proposed in the ICM 2018 criteria. For LE (10 EA), the sensitivity was 81% (95% CI 66% to 91%) and specificity was 99% (95% CI 91% to 100%); for LE (BM 10), sensitivity was 81% (95% CI 65% to 91%) and specificity was 97% (95% CI 89% to 100%). CONCLUSION: A rapid off-label D-lactic acid strip test is valuable for diagnosing PJI. The results of this study indicate very good accuracy with comparable sensitivity and specificity for both LE strip tests. The usefulness of the test in a group of patients with chronic inflammatory diseases and the reproducibility of the reading by different researchers were not analyzed in this study and require further investigations. Before a rapid D-lactic strip test is routinely used for diagnosing PJI, multicenter studies on a larger group of patients should be conducted.Level of Evidence Level II, diagnostic study.

Lateral or Medial Parapatellar Surgical Approach to the Valgus Osteoarthritic Knee? A Retrospective Single-Center Study.

Aims: Total knee arthroplasty in patients with fixed valgus deformity is a demanding procedure. The aim of this study was to compare the clinical results of using the lateral approach [LA] versus the medial approach [MA] in the treatment of fixed valgus knee deformities. Methods: This single-center study compared the results of 143 consecutive patients with fixed valgus deformity (mean 21.55° valgus, mean age 68.2 years) undergoing LA Total Knee Arthroplasty [TKA] to 50 patients (mean 16.58° valgus, mean age 67.2 years) undergoing MA TKA. The mean follow-up period was 5.1 years (2−10 years). Data was collected from operative notes, routine postoperative visits, and radiological findings. Apart from a radiological evaluation, patients were clinically assessed both pre- and postoperatively using the Knee Society Score [KSS]. Descriptive statistics together with the Kolmogorov-Smirnov test, the Student's t-test for independent samples, and the Mann-Whitney U test were used. The level of significance in this study was α = 0.05. Results: In the LA group, the KSS Knee was significantly higher than in the MA group [85.31 vs. 77.42, respectively, p-value < 0.001]. The difference was also in the KSS total but with no statistical significance [155.17 vs. 149.22, p-value 0.087]. The surgery time in the LA group was shorter than in the MA group [81 vs. 91 min, respectively, p-value­0.002]. The complication rate after surgery was higher in the MA group than in the LA group (14% vs. 9%, respectively). Conclusions: The lateral approach is a good alternative to the standard medial parapatellar approach in the treatment of fixed valgus knee deformities. A higher postoperative KSS Knee, shorter surgery time, and similar complication rate make the lateral approach a valuable option for treating patients with osteoarthritis and fixed valgus knee deformity.

Periprosthetic Joint Infections Caused by Candida Species-A Single-Center Experience and Systematic Review of the Literature.

BACKGROUND: The aim of this study was to analyze the treatment results of fungal periprosthetic joint infections (PJI) caused by Candida species from a single orthopedic center and to compare them with reports from other institutions. METHODS: Eight patients operated on from January 2014 to December 2021 met the inclusion criteria and were analyzed in terms of clinical outcomes. A systematic review of the literature identified 153 patients with Candida PJIs extracted from 12 studies according to the PRISMA (Preferred Reporting Item for Systematic Reviews and Meta-Analyses) guidelines. RESULTS: The success rate of the treatment in the case series was 50%. The most frequent pathogens were Candida albicans (three cases; 37.5%) and Candida parapsilosis (three cases; 37.5%). In one patient (12.5%), bacterial co-infection was noted, and in five patients (62.5%) significant risk factors of PJI were confirmed. The overall success rate on the basis of data collected for systematic review was 65.5%. A sub-analysis of 127 patients revealed statistically significant differences (p = 0.02) with a higher success rate for the knees (77.6%) than for the hips (58%). In 10 studies the analysis of risk factors was performed and among 106 patients in 77 (72.6%) comorbidities predispose to fungal PJI were confirmed. Bacterial co-infection was noted in 84 patients (54.9%). In 93 patients (60.7%) Candida albicans was the culprit pathogen, and in 39 patients (25.5%) Candida parapsilosis was the culprit pathogen. Based on these two most frequent Candida species causing PJI, the success rate of the treatment was statistically different (p = 0.03), and was 60.3% and 83.3%, respectively. The two-stage strategy was more favorable for patients with Candida parapsilosis infections (94.4% success rate) than the one-stage protocol (50% success rate; p = 0.02); as well as in comparison to the two-stage treatment of Candida albicans (65% success rate; p = 0.04). CONCLUSIONS: The analysis of the literature showed no differences in the overall success rate between one- and two-stage surgical strategies for all Candida species, but differed significantly comparing the two most frequent strains and concerning PJI localization. The frequent presence of bacterial co-infections makes it necessary to consider the additional administration of antibiotics in the case of fungal PJI.

Shaft Fractures in Patients Requiring Primary or Revision Total Knee Arthroplasty Can Be Successfully Treated with Long-Stemmed Implants without Additional Fixation.

The aim of this study was to evaluate the bone union, complication rate, clinical and functional outcomes of long-stemmed total knee arthroplasty (TKA) in patients with periprosthetic femoral or tibial shaft fractures and in patients with femoral or tibial shaft fractures with coexisting advanced knee osteoarthritis (OA). This retrospective study comprised 25 patients who underwent surgery due to tibial or femoral shaft fractures: (1) with coexisting severe knee OA or (2) with a periprosthetic fracture requiring implant exchange. In all cases, fracture stabilization was performed intramedullary with the use of long-stemmed implants without the use of additional fixation material (plates, screws, or cerclage). Bone union was achieved in 22/25 patients (88%). One patient required revision with additional plate stabilization due to non-union, and asymptomatic partial bone union was observed in two cases. The group with periprosthetic fractures demonstrated good clinical (mean 73.1 ± 13.3) and moderate functional (mean 59.2 ± 18.8) outcomes in the Knee Society Scoring system (KSS). In the group with shaft fracture and coexisting OA significantly higher clinical (excellent results, mean 84.1 ± 11; p = 0.03) and functional (good results, mean 76.2 ± 20.6; p = 0.04) results were noted. There were no statistically significant differences in terms of range of motion (ROM) or complication rate between these two groups. One-stage TKA with a long-stemmed implant without the use of additional fixation material is an effective method for the treatment of femoral or tibial shaft fractures in patients who require joint replacement. Despite being technically demanding, the approach yields bone union and moderate to excellent clinical and functional outcomes with a relatively low complication rate.

Pelvic incidence and pelvic tilt can be calculated using either the femoral heads or acetabular domes in patients with hip osteoarthritis.

AIMS: The aim of the study was to compare two methods of calculating pelvic incidence (PI) and pelvic tilt (PT), either by using the femoral heads or acetabular domes to determine the bicoxofemoral axis, in patients with unilateral or bilateral primary hip osteoarthritis (OA). METHODS: PI and PT were measured on standing lateral radiographs of the spine in two groups: 50 patients with unilateral (Group I) and 50 patients with bilateral hip OA (Group II), using the femoral heads or acetabular domes to define the bicoxofemoral axis. Agreement between the methods was determined by intraclass correlation coefficient (ICC) and the standard error of measurement (SEm). The intraobserver reproducibility and interobserver reliability of the two methods were analyzed on 31 radiographs in both groups to calculate ICC and SEm. RESULTS: In both groups, excellent agreement between the two methods was obtained, with ICC of 0.99 and SEm 0.3° for Group I, and ICC 0.99 and SEm 0.4° for Group II. The intraobserver reproducibility was excellent for both methods in both groups, with an ICC of at least 0.97 and SEm not exceeding 0.8°. The study also revealed excellent interobserver reliability for both methods in both groups, with ICC 0.99 and SEm 0.5° or less. CONCLUSION: Either the femoral heads or acetabular domes can be used to define the bicoxofemoral axis on the lateral standing radiographs of the spine for measuring PI and PT in patients with idiopathic unilateral or bilateral hip OA. Cite this article: Bone Joint J 2021;103-B(8):1345-1350.

Efficacy of intravenous tranexamic acid administration in revision hip arthroplasty.

BACKGROUND: This study aimed to evaluate the efficiency of constant dose intravenous administration of tranexamic acid (TXA) in reducing postoperative blood loss, hemoglobin (Hb) concentration, and the number of transfusions in revision hip arthroplasty (RHA). METHODS: The study included 145 consecutive patients who had undergone RHA: a TXA group (75 patients) who received two doses of TXA (1.0 g 15 min before skin incision and 1.0 g during wound closure) and a no-TXA group (70 patients). Percentage blood loss and quantitative blood loss were calculated. RESULTS: The percentage blood loss (23.82 ± 10.6% vs. 39.17 ± 15.1%; P < 0.001), Hb drop (2.9 ± 1.14 g/dL vs. 4.22 ± 1.4 g/dL; P < 0.001), and total blood loss (1030 ± 477 mL vs. 1736 ± 761 mL; P < 0.001) were significantly lower in the TXA group than in the no-TXA group on postoperative day 1. Percentage blood loss (37.5 ± 10.4% vs. 43.1 ± 12.5%; P < 0.01), Hb drop (4.64 ± 1.5 g/dL vs. 5.22 ± 1.6 g/dL; P < 0.01) and total blood loss (1639 ± 543 mL vs. 1908 ± 681 mL; P = 0.02) were significantly lower in the TXA group than in the no-TXA group on the 5th postoperative day. The blood transfusion requirements were lower in the TXA group than those in the no-TXA group (30.7% vs. 71.4% of patients; P < 0.001), with a lower transfusion per patient ratio of 0.55 in the TXA group and 1.4 in the no-TXA group. No postoperative complications were associated with TXA administration, including deep-vein thrombosis and pulmonary embolism. CONCLUSION: Administration of TXA is an effective method to reduce perioperative blood loss, Hb drop and the number of transfusions in RHA.

Blood and synovial fluid calprotectin as biomarkers to diagnose chronic hip and knee periprosthetic joint infections.

AIMS: Calprotectin (CLP) is produced in neutrophils and monocytes and released into body fluids as a result of inflammation or infection. The aim of this study was to evaluate the utility of blood and synovial CLP in the diagnosis of chronic periprosthetic joint infection (PJI). METHODS: Blood and synovial fluid samples were collected prospectively from 195 patients undergoing primary or revision hip and knee arthroplasty. Patients were divided into five groups: 1) primary total hip and knee arthroplasty performed due to idiopathic osteoarthritis (OA; n = 60); 2) revision hip and knee arthroplasty performed due to aseptic failure of the implant (AR-TJR; n = 40); 3) patients with a confirmed diagnosis of chronic PJI awaiting surgery (n = 45); 4) patients who have finished the first stage of the PJI treatment with the use of cemented spacer and were qualified for replantation procedure (SR-TJR; n = 25), and 5) patients with rheumatoid arthritis undergoing primary total hip and knee arthroplasty (RA; n = 25). CLP concentrations were measured quantitatively in the blood and synovial fluid using an immunoturbidimetric assay. Additionally, blood and synovial CRP, blood interleukin-6 (IL-6), and ESR were measured, and a leucocyte esterase (LE) strip test was performed. RESULTS: Patients with PJI had higher CLP concentrations than those undergoing aseptic revision in blood (median PJI 2.14 mg/l (interquartile range (IQR) 1.37 to 3.56) vs AR-TJR 0.66 mg/l (IQR 0.3 to 0.83); p < 0.001) and synovial fluid samples (median PJI 20.46 mg/l (IQR 14.3 to 22.36) vs AR-TJR 0.7 mg/l (IQR 0.41 to 0.95); p < 0.001). With a cut-off value of 1.0 mg/l, blood CLP showed a sensitivity, specificity, positive predictive value, and negative predictive value of 93.3%, 87.5%, 89.4%, and 92.1%, respectively. For synovial fluid with a cut-off value of 1.5 mg/l, these were 95.6%, 95%, 95.5%, and 95%, respectively. CONCLUSION: This small study suggests that synovial and blood CLP are useful markers in chronic PJI diagnosis with similar or higher sensitivity and specificity than routinely used markers such as CRP, ESR, IL-6, and LE. CLP was not useful to differentiate patients with PJI from those with rheumatoid arthritis. Cite this article: Bone Joint J 2021;103-B(1):46-55.

Ultrasound frequency of sonication applied in microbiological diagnostics has a major impact on viability of bacteria causing PJI.

OBJECTIVES: Sonication of explanted prosthesis constitutes an element of microbiological diagnostics. The aim of performing this procedure is to remove biofilm and to increase sensitivity of diagnostics. Ultrasound used in medical purposes are low-frequency and low-intensity. With this wide range of frequency which can be used in sonication process it is necessary to find the golden mean between biofilm dislodging and planktonic bacteria sparing. MATERIALS AND METHODS: The aim of this study was to determine the least harming low-intensity ultrasound frequency (35 kHz, 40 kHz or 53 kHz) used during sonication process with other parameters constant. Four bacteria species were examined: S. aureus, E. faecalis, E. coli, K. pneumoniae. Number of microbiological studies (n) for each group (g) counted 40 specimens (based on scheme 1 bacteria type - 4 groups, 40 studies each). RESULTS: A detailed analysis of gathered data was conducted. Based on study findings following conclusions were drawn. Sonication has a significant and negative impact on survival of sonicated planktonic bacteria. Part of bacteria in planktonic state are damaged/killed by ultrasound, which is demonstrated by lower CFU count in sonicated samples versus control group. CONCLUSIONS: Optimal ultrasound frequencies for sonication of S. aureus, P. aeruginosa and E. coli are 35 kHz and 40 kHz. Ultrasound frequencies used in sonication process (35 kHz, 40 kHz, 53 kHz) of E. coli showed same impact on bacteria survival. It is crucial to perform further assessment of ultrasound parameters on clinical effects of sonication used in PJI diagnostics.

Total knee arthroplasty with simultaneous tibial shaft osteotomy in patient with multiple hereditary osteochondromas and multiaxial limb deformity - a case report.

BACKGROUND: Hereditary multiple osteochondromas (hereditary multiple exostoses, HME) is a rare genetic disease characterized by the development of benign osteocartilaginous tumors that may cause severe limb deformities and early onset osteoarthritis. Total knee arthroplasty (TKA) is the method of choice for the treatment of advanced gonarthrosis, however the surgical management with coexisting severe axial limb deformity remains unclear. CASE PRESENTATION: 65-year-old man with HME and extra-articular multi-axial limb deformity was admitted to the orthopedic department due to chronic knee pain and limited range of motion caused by secondary osteoarthritis. Regarding to the clinical and radiological examinations, after preoperative planning he was qualified to a one-stage TKA combined with tibial shaft osteotomy (TSO). In a one year follow-up full bone union was confirmed with no signs of implant loosening or prosthesis displacement. Patient was very satisfied, did not report any joint pain and has sufficient range of motion without knee instability. CONCLUSION: The improvement of mechanical axis during TKA is a crucial factor for achieve operative success and long implant survival. Despite the higher risk of complication rate in comparison to two-stage treatment, one-stage TKA with simultaneous TSO should be a considerable method for patients with osteoarthritis and multiaxial limb deformities. This method can give a good clinical and functional outcomes, however should be performed subsequently to careful preoperative planning and proper patient qualification.

Success Rates of Revision Knee Arthroplasty for Periprosthetic Joint Infection in Rheumatoid and Non-Rheumatoid Arthritis Patients.

This study evaluated the success and failure rates as well as the final results following 2-stage revision total knee arthroplasty (TKA) for periprosthetic joint infection (PJI). Particular emphasis was placed on comparing patients with rheumatoid arthritis (RA) and non-RA patients. A total of 140 knees that required 2-stage revision for PJI after TKA were analyzed. Mean patient age at first revision TKA was 67.9 years (range, 43 to 89 years), and mean time from second-stage revision to final follow-up was 53.3 months (range, 26 to 127 months). Thirty-eight of the 140 knees (27.1%) demonstrated recurrence of infection after first 2-stage revision. Of these, 8 required another 2-stage revision, 25 required knee arthrodesis, and 2 required amputation; 3 patients refused further treatment or were lost to follow-up. There was no recurrence of infection. No statistically significant differences were observed between the RA and non-RA groups in terms of success or failure rate (P=.6) according to Diaz-Ledezma and Knee Society Scores (P=.3). These findings indicate reinfection rates and final results were similar in RA and non-RA patients following revision TKA for PJI. [Orthopedics. 2019; 42(5):e472-e476.].

The Influence of Implant Position on Final Clinical Outcome and Gait Analysis after Total Knee Arthroplasty.

The aim of the study was to evaluate the impact of implant component alignment on objective and subjective outcomes after total knee arthroplasty (TKA). The rotation of the femoral component and its influence on the final results were also examined. After exclusion, the study examined 102 patients (mean age, 66.28 years; range, 51-79 years) who had undergone unilateral TKA. All of the operative procedures were performed by one surgeon with one type of implant. One year after the operation, improvements in Knee Society's Knee Scoring System, functional score, Western Ontario and McMaster Universities Osteoarthritis Index, and Visual Analog Scale were observed; however, none showed a significant correlation with any of the parameters analyzed by X-ray or computed tomography (CT) (α, ß, γ, δ angles and posterior condylar angle [PCA]). Significant improvements were found for the vast majority of the parameters used for gate analysis at the final follow-up. Significant correlations were found between PCA angle and differences in stance phase, swing phase of the operated limb, and step width (all p = 0.03). No other significant relationships were found between gait parameters and indicators measured by X-ray and CT. None of the analyzed radiographic parameters, including rotation of the femoral component, correlated with final clinical results. Neither femoral internal rotation of 3° to 6°, nor rotation of 0° ± 3° or 0° ± 6° influenced the outcome. One year after TKA, a significant improvement was observed in both functional and gait parameters.

A Prospective, Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Study Evaluating Meniscal Healing, Clinical Outcomes, and Safety in Patients Undergoing Meniscal Repair of Unstable, Complete Vertical Meniscal Tears (Bucket Handle) Augmented with Platelet-Rich Plasma.

OBJECTIVE: The present study aimed to investigate the effectiveness and safety of platelet-rich plasma (PRP) application in arthroscopic repair of complete vertical tear of meniscus located in the red-white zone. METHODS: This single center, prospective, randomized, double-blind, placebo-controlled, parallel-arm study included 37 patients with complete vertical meniscus tears. Patients received an intrarepair site injection of either PRP or sterile 0.9% saline during an index arthroscopy. The primary endpoint was the rate of meniscus healing in the two groups. The secondary endpoints were changes in the International Knee Documentation Committee (IKDC) score, Knee Injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and analog scale (VAS) in the two groups at 42 months. RESULTS: After 18 weeks, the meniscus healing rate was significantly higher in the PRP-treated group than in the control group (85% versus 47%, P = 0.048). Functional outcomes were significantly better 42 months after treatment than at baseline in both groups. The IKDC score, WOMAC, and KOOS were significantly better in the PRP-treated group than in the control group. No adverse events were reported during the study period. CONCLUSIONS: The findings of this study indicate that PRP augmentation in meniscus repair results in improvements in both meniscus healing and functional outcome.

Hip osteonecroses treated with calcium sulfate-calcium phosphate bone graft substitute have different results according to the cause of osteonecrosis: alcohol abuse or corticosteroid-induced.

INTRODUCTION: The aim of the study was to assess the factors influencing the final results of treatment of the femoral head osteonecrosis (ONFH) with core decompression and bone substitute grafting. The special interest was focused on comparison between alcohol- and steroid-induced ONFHs. MATERIAL AND METHODS: In this prospective study, a total of 53 patients (58 hips) in the mean age of 35.5 years were included: 29 had a history of alcohol use (32 hips) and 24 of steroid use (26 hips). The mean follow-up was 4.2 years (minimum 3 years). RESULTS: At last follow-up, significant improvements were noted in the Harris Hip Score (HHS) (mean 44.0 vs 55.9 points, p < 0.00002) and VAS scores (mean 7.0 vs 5.8 points, p < 0.0002) for the whole ONFH cohort, comparing to pre-operative status. The degree of improvement did not differ between Ficat and Arlet grade II and grade III (mean 14.9 vs 6.2 points, respectively, p = 0.1). No change was found between the final and initial results in this group in the steroid group (HHS mean 42.2 vs 45.5 points, p = 0.5 and VAS mean 6.8 vs 6.5 points, p = 0.5), but the improvement was noted in the alcohol group (HHS mean 45.5 vs 64.4 points, p < 0.0001; VAS mean 7.1 vs 5.2 points, p < 0.0001) comparing to pre-operative status. CONCLUSIONS: Presented treatment of ONFH significantly improves hip function, offers pain reduction, and gives similar functional improvement for hips scoring grade II and III on the Ficat and Arlet scale. A good response to operative treatment is seen in patients with alcohol-induced ONFH, but not in those with steroid-induced ONFH.

Short and mid term results of revision total knee arthroplasty with Global Modular Replacement System.

BACKGROUND: The original knee megaprostheses with fixed or rotating hinge articulation were custom made and only used for reconstruction of the knee following distal femoral or proximal tibial tumor resections. The aim of the study was to analyze the short- and mid-term results of revision total knee arthroplasty with Global Modular Replacement System (GMRS) used in difficult situations not amenable to reconstruction with standard total knee replacement implants. MATERIALS AND METHODS: Nine patients (9 knees) were treated with this comprehensive modular implant system, with a mean age of 73.7 years (range 56-83 years) and a mean followup of 5 years (range 3-8 years). Two patients were treated for distal femoral nonunion, five for distal femur periprosthetic fracture and two for periprosthetic joint infection. RESULTS: The mean Knee Society Score: Knee and functional scores were 77.9 and 40 points, respectively. All demonstrated full extension and flexion was at least 90°. Recurrence of infection was present in one patient. No signs of loosening, dislocation, or implant failure were observed. CONCLUSIONS: Based on our small series of patients that represent severe cases, GMRS provides relatively good mid-term functional results, pain relief, and good implant survivorship with a low complication rate. This salvage procedure allows elderly, infirm patients to regain early ambulatory ability.

Two stage revision hip arthroplasty in periprosthetic joint infection. Comparison study: with or without the use of a spacer.

PURPOSE: The aim of this study was to compare two methods of two-stage surgery for PJI (periprosthetic joint infection) after THA (total hip arthroplasty): one with and one without the use of an antibiotic-loaded cement spacer. METHODS: This retrospective study was performed on 99 consecutive patients (99 hips) with a minimum follow-up of 24 months. Patients were divided into two groups: (1) in whom the operation was performed using a spacer, and (2) for whom a spacer was not used. RESULTS: For the whole cohort, the results improved between pre-operative and final follow-up. Recurrence of infection was found in nine out of 98 patients (9.2%) and was not significantly different between the two groups. Patients treated with a spacer had better functional improvement in the interim period, but the VAS score was better in the non-spacer group. The improvement in final function was better in the spacer group with regard to HHS, but not according to WOMAC score or VAS at final follow-up. CONCLUSION: The resection arthroplasty should be awarded particular consideration in cases of poor soft tissue quality, bone stock deficiency, when complications related to spacer use are expected or chances of new hip endoprosthesis implantation are low.

Neutrophil-to-lymphocyte ratio shows faster changing kinetics than C-reactive protein after total hip and knee arthroplasty.

BACKGROUND: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) induce inflammatory reactions, which can be described by changes in the neuroendocrine, cellular, protein, and cytokine systems. The aim of this study was to document the normal distribution pattern of the neutrophil-to-lymphocyte ratio (NLR) after THA and TKA and to compare it with postoperative C-reactive protein (CRP) patterns. METHODS: Changes in serum CRP levels, neutrophil count, and lymphocyte count were measured before and during the first 5 postoperative days in a prospective study performed on 387 patients undergoing total hip or knee arthroplasty. RESULTS: Mean CRP levels in patients undergoing THA were 7.7 mg/L, 184.8 mg/L, and 115.9 mg/L, respectively, at Days 0, 3 and 5. The mean NLR of patients undergoing THA was 2.9, 3.6, and 2.7, respectively, at Days 0, 3, and 5. Mean CRP levels in patients undergoing TKA were 7.8 mg/L, 192.6 mg/L, and 108.6 mg/L, respectively, at Days 0, 3 and 5. The mean NLR of patients undergoing TKA was 2.8, 3.4, and 2.6, respectively, at Days 0, 3, and 5. When comparing the preoperative value and the Day 3 value, CRP levels increased more than the NLR (almost a 24-fold increase in mean CRP values vs. a 1.2-fold increase in mean NLR values). In both groups, the NLR returned to preoperative values by the 5th postoperative day. CONCLUSIONS: The present study demonstrated a significant elevation in CRP levels and the NLR following THA and TKA. In both groups, the NLR showed a faster kinetics pattern than CRP levels in response to surgical trauma.The translational potential of this article: We describe results of the use of the NLR, as compared to a routinely used marker, CRP, as advantageous in clinical setting due to faster dynamics of change. Integrating the NLR in clinical practice seems easy and without extra cost.