Synovial calprotectin in prosthetic joint infection. A systematic review and meta-analysis of the literature.

INTRODUCTION: Calprotectin is a protein endowed with antimicrobial properties, rendering it a distinctive marker for infection. Two methods are currently available for the assay of calprotectin: the enzyme-linked immunosorbent assay (ELISA) and the lateral flow test (LFT). We aimed to assess the diagnostic accuracy of synovial fluid calprotectin and to compare the accuracy of the laboratory-based test and the qualitative assessment for the diagnosis of hip and knee prosthetic infection. MATERIALS AND METHODS: We searched (from inception to November 2023) MEDLINE, Scopus, EMBASE, Web of Science, and Cochrane for studies on calprotectin in the diagnosis of periprosthetic joint infection (PJI). Sensitivity, specificity, positive and negative likelihood ratio (LR), and diagnostic odds ratio were analyzed. The receiver-operating curve for each method was calculated. RESULTS: We included 14 articles in our meta-analysis, including 902 patients who underwent total hip and knee arthroplasties revision; 331 (37%) had a joint infection according to MSIS, MSIS-modified criteria, ICM 2018 and EBJIS 2021. Considering the false-positive result rate of 6% and false-negative result rate of 7%, pooled sensitivity and specificity were 0.92 (95% CI 0.89-0.94) and 0.93 (0.91-0.95), respectively. The area under the curve (AUC) was 0.93 (95% CI 0.91-0.94). No statistical differences in terms of sensitivity and specificity were found between ELISA and LFT. The pooled sensitivity and specificity of the two calprotectin assessment methods were: LFT 0.90 (95% CI 0.869-0.935) and 0.92 (95% CI 0.894-0.941), respectively; ELISA 0.96 (95% CI 0.914-0.986) and 0.97 (95% CI 0.934-0.988), respectively. The diagnostic odds ratio of the ELISA was superior to that of the LFT (906.6667, 95% CI 271.2686-3030.3712 versus 113.8886, 95% CI 70.4001-184.2414; p < 0.001). The AUC for ELISA and LFT was 0.968 (95% CI 0.944-0.984) and 0.915 (95% CI 0.895-0.933), respectively. CONCLUSIONS: Detection of synovial calprotectin is an accurate test for diagnosis of hip and knee prosthetic infections. The diagnostic accuracy of the two calprotectin assessment methods is almost comparable. The LFT is a valid, rapid, and more available diagnostic tool, particularly to rule out PJI.

Articulating spacers in elderly patients affected by periprosthetic knee infection: clinical findings and outcome.

OBJECTIVE: Although the two-stage technique is a validated strategy in periprosthetic joint infections, there is a lack of data on the patients' clinical outcomes after the spacer placement. This study aims at evaluating the quality of life, joint function, and pain in patients over 70 years affected by periprosthetic joint infection treated with a two-stage exchange using metal on polyethylene spacers. PATIENTS AND METHODS: We conducted a follow-up study to evaluate the quality of life and functionality of consecutive patients over 70 years treated for PJI at our institution using a validated assessment set including the Western Ontario and Mac Master University (WOMAC) score, Knee Society Score (KSS), numerical rating scale (NRS). Knee Range of Movement (ROM) before and after the surgery was also analyzed. RESULTS: Forty-five patients with a mean age of 76 ± 5.3 years were included. Coagulase-negative staphylococci were the most isolated microorganisms. In the preoperative study group, the WOMAC score was 48.4 ± 18.9, and the KSS objective and functional scores were 37.6 ± 17.3 and 27.6 ± 22.3, respectively. NRS was 7.3 ± 1.8. After three months of follow-up, we found better results than preoperative clinical evaluation. We retrieved similar results comparing our post-operative PROMS (WOMAC and KSS scores) with published thresholds for treatment success two months after primary total knee arthroplasty. The infection eradication rate was 87%. CONCLUSIONS: The two-stage technique confirmed its efficacy in the treatment of PJI. Patients over 70 years who had undergone the first stage of the two-stage technique for PJI showed a good quality of life and knee function.

Blood loss and transfusion rate in patients undergoing two-stage exchange in infected total knee arthroplasty.

Two-stage exchange in infected total knee arthroplasty is a reliable technique, but it has a high rate of blood loss. The study aims to compare the pre-operative and post-operative haemoglobin levels, the rate of transfusion, and the blood loss in two-stage exchange. From July 2018 to July 2019, eighteen patients underwent two-stage exchange of their infected total knee arthroplasty. Local and systemic tranexamic acid was administered in both surgical stages. Calculated blood loss was 2246 mL (range 1528 - 2850) in the first stage and 2388 mL (1873 - 2829) during reimplantation, respectively. The corresponding transfusion rate was 55 % and 67%, respectively. With the numbers available, these differences were not significant. In conclusion, this study shows that the blood loss and transfusion rate are similar during the two stages of exchange knee arthroplasty for infection.

A comparative study of combined intravenous and topical administration of tranexamic acid with topical tranexamic acid alone for blood loss reduction after primary uncemented total hip arthroplasty.

The aim of the present study was to evaluate the efficacy of topical versus combined (intravenous + topical) tranexamic acid (TXA) to reduce perioperative blood loss after uncemented primary total hip arthroplasty (THA). Seventy-five patients were randomized in three comparable experimental groups: 1) topical TXA (3 g in 50 ml of saline solution); 2) intravenous + topical TXA (3 g topical + 2 g in 100 ml of saline solution intravenously); 3) controls. Pre- and post-operative hemoglobin (Hb) levels and hematocrit (Hct) values along with the rate of blood transfusion in the 3 groups were compared. The intravenous + topical TXA group demonstrated higher Hb levels and Hct values at postoperative day one (Hb = p <0.05, Hct = p <0.001), postoperative day three (Hb = p <0.05, Hct = p <0.001), and discharge (Hct = p <0.01) compared to the control group. The intravenous + topical group had a lower transfusion rate compared to the control group (0% vs 20%, p = 0.014). With the numbers available, no difference in postoperative Hb level and transfusion rate emerged between topical TXA and control group.

Volar distal radius vascularized bone graft vs non-vascularized bone graft: a prospective comparative study.

The pseudoarthrosis (PSA) of scaphoid leads to alteration in load transfer in the wrist joint. Its treatment aims to achieve consolidation to improve clinical complaints and prevent post-traumatic arthritis. The indication for using vascularized bone grafts is still controversial. This prospective comparative study aimed to compare consolidation rate and time to healing of scaphoid PSA treated by volar distal radius vascularized bone graft vs non-vascularized iliac bone graft. Nine patients underwent vascularized grafting of scaphoid PSA. These patients were compared to a control group consisting of twelve patients treated with iliac crest-free bone graft. PSA consolidation was obtained in 8 of 9 patients (88%) and 9 of 12 patients (75%) in the study and control group, respectively. The difference in consolidation rate was not significant. Two of three patients with AVN of the proximal pole in the study group (66%) went to consolidation. In the control group no patient with AVN obtained bone consolidation. This difference almost reached statistical significance (p = 0.083). The mean time to consolidation was 8.6 weeks (range 8-11) and 11.7 weeks (range 10-16), respectively, in the study and control group. This difference was significant (p < 0.05). In conclusion, the distal radius vascularized graft led to satisfactory consolidation rate of PSA in the current study, even in cases of AVN of the proximal pole. Moreover, the vascularized bone graft resulted in shorter healing time compared to the non-vascularized graft.

Clinical and prognostic features of prosthetic joint infections caused by Enterococcus spp.

OBJECTIVE: Pathogens colonizing the intestinal or urinary tract such as enterococci or Gram-negative bacilli can cause prosthetic joint infection (PJI). PATIENTS AND METHODS: PJI undergoing 2-stage exchange, referred to the Department of Infectious Diseases of the Cotugno Hospital of Naples and the Fondazione Policlinico Gemelli of Rome over a 7-year period (2009-2015) for Infectious Diseases (ID) consultation were included. Demographic data, detailed information about previous or underlying diseases, findings of the clinical examination, and results of laboratory investigations were analyzed. The cure was defined by the disappearance of clinical, laboratory, and radiological evidence of PJI 96 week after the discontinuation of antibiotic treatment. RESULTS: Thirty-one cases of PJI sustained by Enterococci were included (16 early infections, 13 delayed infections, and 2 late infections). Median age was 73 years (range 39-83), 39% were males. Comorbidities related to an increased risk of infection were reported in 17 (55%) cases. Joint pain interfering with daily living was reported in 27 (87%) cases, fever in 7 with early infection and in no case with delayed or late infection (7/17 vs. 0/14, Odds ratio undefined, p=0.01). Local inflammation and joint effusion were reported in 29 (93%) cases, sinus tract in 25 (81%). Enterococcus faecalis was the etiologic agent in 28 (90%) cases, E. faecium in 2 (6%), E. casseliflavus in 1 (3%). Eleven cases were polymicrobial. Favourable outcome was reported in 20 (65%) cases. Patients with comorbidities reported more frequently an unfavourable outcome (9/17 vs. 2/14, Odds ratio 6.7, 95% CI 1.1-39.8; p=0.06). CONCLUSIONS: Comorbidities should arise the suspect of infection by enterococci. Associative protocols, considering drugs active against biofilm should be considered in the cases with enterococcal infection.

Post-arthroscopic septic arthritis of the knee. Analysis of the outcome after treatment in a case series and systematic literature review.

OBJECTIVE: The aim of this study was to review the characteristics of patients with septic arthritis after ACL reconstruction comparing our results with those deriving from the literature review. PATIENTS AND METHODS: Patients with suspected post arthroscopic septic arthritis of the knee occurring within 6 months after surgery were evaluated to be included in the investigation. Septic arthritis was defined by i) clinical evidence; ii) laboratory investigations; iii) synovial fluid leukocyte count of more than 2,5 x 104/µL or positive cultures obtained by synovial fluid aspirate. RESULTS: Thirty-nine patients (median age 25 years, range 17-42) with septic arthritis following ACL reconstruction were enrolled. Staphylococci were the main bacteria identified. Resolution within 4 weeks of local signs was observed more frequently in those receiving arthroscopic debridement and synovectomy coupled with antibiotic therapy (18/21 vs. 9/18, p<0.05). Fever was present in 33 (85%) cases. Fever disappearance and CRP normalization within 4 weeks were reported more frequently in patients receiving intravenous antibiotics (17/20 vs. 9/19, p<0.05). Similar findings were retrieved by literature analysis. CONCLUSIONS: An intravenous antibiotic therapy with surgical debridement is the first-line treatment for septic arthritis. Staphylococci are the main causative agents, justifying an empiric therapeutic approach with an anti-MRSA agent and cephalosporin.

Tantalum monoblock cups in total hip arthroplasty: clinical results and outcome predictors.

This study aims to report the minimum 2-year follow-up results of the tantalum monoblock cup in primary THA and to identify possible outcome predictors. Eighty-eight porous tantalum monoblock acetabular cup in primary THA were reviewed. The Harris Hip Score (HHS) and the Short Form-36 Health Survey (SF-36) were used for the evaluation of outcomes. Radiographic evaluation included acetabular component orientation, presence of bone gaps, radiolucent lines, new bone formation and heterotopic ossifications. After a mean follow-up of 55.4±19.5 months, no component revision was noted. The HHS improved from 43.6±14.6 to 88.3±8.4 (P less than 0.001). The mean physical domain of the SF-36 did not significantly differ from that of age-matched, healthy subjects (P=0.072); the mean mental component of the SF-36 was significantly higher than that of age-matched, healthy subjects (P less than 0.001). Negative determinants of postoperative HHS (total adjusted R2=0.328) using tantalum monoblock cups were age at surgery (R2=0.164, P less than 0.001), female sex (R2=0.103, P less than 0.001), and acetabular inclination (R2=0.084, P equals 0.003).

Treatment of Proximal Scaphoid Non-union by Resection of the Proximal Pole and Palmaris Longus Interposition Arthroplasty.

BACKGROUND: The purpose of this study was to determine the long-term clinical and radiographic outcome in a group of patients treated with resection of the proximal pole and tendon ball arthroplasty because of a scaphoid non-union. PATIENTS AND METHODS: 15 patients affected by scaphoid non-union and treated with resection arthroplasty were studied at a mean follow-up of 9.1 years. The assessment included a visual analogue scale (VAS) to evaluate pain, the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, and the measurement of grip and pinch strength. We also evaluated pre-operative and follow-up radiographs to determine the stage of SNAC wrist. RESULTS: We obtained a good subjective clinical result in 11 patients and a poor result in 4. Mean VAS and DASH score at follow-up was 1.2±1.2 and 12±12,1, respectively. Grip and key pinch strength in the surgically treated hand were 89% of the contralateral hand. There was significant increase in the SNAC stage at follow-up with respect to the preoperative evaluation in the operated wrist. CONCLUSION: Resection of the proximal pole and tendon ball arthroplasty provided long-term relief of pain and good functional results in most patients affected by scaphoid non-union. This technique did not affect the natural history of SNAC wrist with its clinical and functional consequences.

The determinants of mortality and morbidity during the year following fracture of the hip: a prospective study.

Several studies have reported the rate of post-operative mortality after the surgical treatment of a fracture of the hip, but few data are available regarding the delayed morbidity. In this prospective study, we identified 568 patients who underwent surgery for a fracture of the hip and who were followed for one year. Multivariate analysis was carried out to identify possible predictors of mortality and morbidity. The 30-day, four-month and one-year rates of mortality were 4.3%, 11.4%, and 18.8%, respectively. General complications and pre-operative comorbidities represented the basic predictors of mortality at any time interval (p < 0.01). In-hospital, four-month and one-year general complications occurred in 29.4%, 18.6% and 6.7% of patients, respectively. After adjusting for confounding variables, comorbidities and poor cognitive status determined the likelihood of early and delayed general complications, respectively (p < 0.001). Operative delay was the main predictor of the length of hospital stay (p < 0.001) and was directly related to in-hospital (p = 0.017) and four-month complications (p = 0.008).

RELEASE OF GENTAMICIN FROM CEMENT SPACERS IN TWO-STAGE PROCEDURES FOR HIP AND KNEE PROSTHETIC INFECTION: AN IN VIVO PHARMACOKINETIC STUDY WITH CLINICAL FOLLOW-UP.

Eighteen patients undergoing two-stage exchange arthroplasty for infected total hip or knee arthroplasty using gentamicin-loaded bone cement spacers (80g bone cement, 2 g gentamicin and 2 g clindamycin) were studied. The concentration of gentamicin eluted from the spacers was assessed on samples of blood, urine, and drainage fluid that were collected from each patient at set intervals during the 48 hours following the first-stage surgery. The hip and knee cement spacers showed similar curve of release over the first postoperative hours (early peak followed by slow release), but the mean gentamicin concentration in the drainage fluid was higher in patients with hip spacers compared to patients with knee spacers (30.61±19.47 mg/L vs 17.43±13,63 mg/L, p less than 0.05). In patients with hip spacers, the mean, maximum, and minimum concentration of gentamicin was higher with respect to the minimum inhibitory concentration (MIC) break point for Staphylococcus spp, Pseudomonas Aeruginosa and Enterobacteriaceae throughout the first postoperative 48 h. Conversely, in 25% of patients with a knee spacer a drug concentration below the MIC break point for Gram negative bacteria was found in the drainage fluid after 12 h. Gentamicin levels in the blood samples were negligible over the entire time interval and were steadily well below the renal toxicity reference. The highest urinary concentration of gentamicin was observed between 4 and 9 h postoperatively. Subsequently, it gradually declined until 48 h. Clinically, the rate of cure was 100% at a mean follow-up of 113 weeks (range 90-182). Gentamicin-loaded cement spacers offer the advantage of achieving early high concentrations of the antibiotic directly at the site of infection but especially in the knee a systemic antibiotic therapy must be given as a complement to the spacer implantation to eradicate periprosthetic joint infection (PJI).

Factors related to outcome of early and delayed prosthetic joint infections.

UNLABELLED: In this prospective study, we evaluate the impact of adherence to a diagnostic and therapeutic protocol on prosthetic joint infections (PJI) diagnostic accuracy and outcome. PATIENTS AND METHODS: Patients with early or delayed PJI referred over a 5-year period were included. Diagnosis was based on characteristic clinical signs, radiographic findings and microbiological evidence. Antibiotics were chosen on the basis of microbiological findings, and drugs active against methicillin-resistant staphylococci were administered if no microbiological evidence had been obtained. RESULTS: Inclusion criteria were met in 159 cases (median age 64 years, males 45%). 56 were early infections and 103 delayed infections. Comorbidities were reported in 99 (62%) cases. Positive cultures were obtained in 122/159 (77%), coagulase-negative staphylococci were cultured in 20%, Staphylococcus aureus in 28%, and Pseudomonas aeruginosa in 7%. In early infections, cure rate after debridement and antibiotic therapy was 80%. In delayed infections, cure rate after two-stage exchange was 85%. Of 28 patients with delayed infection treated with antibiotics without surgery, only 8 (29%) infections were suppressed 48 weeks after treatment discontinuation. Rifampin afforded a better outcome. CONCLUSION: Appropriate diagnostic and surgical procedures and microbiologically driven antibiotic therapy including rifampin are recommended to improve diagnostic accuracy and outcome.

Partial trapeziectomy and pyrocarbon interpositional arthroplasty for trapeziometacarpal joint osteoarthritis: results after minimum 2 years of follow-up.

A prospective study was undertaken to assess the outcomes of a series of patients treated using pyrocarbon implant arthroplasty after partial trapeziectomy for trapeziometacarpal joint osteoarthritis. We analysed the results of this procedure in 27 trapeziometacarpal joints of 25 patients. The mean follow-up interval was 34 months (range 26-52). The study showed that pyrocarbon interpositional arthroplasty provided excellent pain relief and high patient satisfaction. Overall function, according to disabilities of the arm, shoulder and hand (DASH) score, improved from 48 points preoperatively to 14 points at the last follow-up assessment. Key pinch strength recorded in the operated hands was comparable with the results obtained in the contralateral hand and in healthy individuals from the same population. No further operations were performed in the study group. Partial trapeziectomy with pyrocarbon arthroplasty may prove to be a successful option for the treatment of trapeziometacarpal joint osteoarthritis. Further long-term comparative studies are warranted.

Long-term clinical results and MRI changes after tendon ball arthroplasty for advanced Kienbock's disease.

The purpose of this study was to assess the long-term clinical results and morphological changes after tendon ball arthroplasty for advanced Kienböck's disease. Twenty-six patients were reviewed, with a mean follow-up interval of 125 months (range 50-226). At follow-up, mean score on the Disabilities of the Arm, Shoulder, and Hand questionnaire was 7.7 and mean visual analogue scale score for pain was 1. Mean carpal height ratio was significantly reduced with respect to the pre-operative value. On magnetic resonance imaging scans, cartilage damage, synovitis, and erosive or oedematous changes in the bones were detected in most patients. Calcification in the defect filled by the tendon ball was seen in all patients. Narrowing of the radioscaphoid joint and the presence of intercarpal synovitis were negatively associated with clinical outcome. Tendon ball arthroplasty in advanced Kienböck's disease results in long-term satisfactory clinical outcomes, despite widespread changes in the bones and joints within the wrist.

Physical, mechanical and pharmacological properties of coloured bone cement with and without antibiotics.

Coloured bone cements have been introduced to make the removal of cement debris easier at the time of primary and revision joint replacement. We evaluated the physical, mechanical and pharmacological effects of adding methylene blue to bone cement with or without antibiotics (gentamicin, vancomycin or both). The addition of methylene blue to plain cement significantly decreased its mean setting time (570 seconds (SD 4) vs 775 seconds (SD 11), p = 0.01), mean compression strength (95.4 MPa (SD 3) vs 100.1 MPa (SD 6), p = 0.03), and mean bending strength (65.2 MPa (SD 5) vs 76.6 MPa (SD 4), p < 0.001) as well as its mean elastic modulus (2744 MPa (SD 97) vs 3281 MPa (SD 110), p < 0.001). The supplementation of the coloured cement with vancomycin and gentamicin decreased its mean bending resistance (55.7 MPa (SD 4) vs 65.2 MPa (SD 5), p < 0.001).The methylene blue significantly decreased the mean release of gentamicin alone (228.2 µg (SD 24) vs 385.5 µg (SD 26), p < 0.001) or in combination with vancomycin (498.5 µg (SD 70) vs 613 µg (SD 25), p = 0.018) from the bone cement. This study demonstrates several theoretical disadvantages of the antibiotic-loaded bone cement coloured with methylene blue.

The functional relevance of neurological recovery after lumbar discectomy: a follow-up of more than 20 years.

We have studied 180 patients (128 men and 52 women) who had undergone lumbar discectomy at a mean of 25.4 years (20 to 32) after operation. Pre-operatively, most patients (70 patients; 38.9%) had abnormal reflexes and/or muscle weakness in the leg (96 patients; 53.3%). At follow-up 42 patients (60%) with abnormal reflexes pre-operatively had fully recovered and 72 (75%) with pre-operative muscle impairment had normal muscle strength. When we looked at patient-reported outcomes, we found that the Short form-36 summary scores were similar to the aged-matched normative values. No disability or minimum disability on the Oswestry disability index was reported by 136 patients (75.6%), and 162 (90%) were satisfied with their operation. The most important predictors of patients' self-reported positive outcome were male gender and higher educational level. No association was detected between muscle recovery and outcome. Most patients who had undergone lumbar discectomy had long-lasting neurological recovery. If the motor deficit persists after operation, patients can still expect a long-term satisfactory outcome, provided that they have relief from pain immediately after surgery.

Minimum 20-year follow-up results of Harrington rod fusion for idiopathic scoliosis.

We evaluated the outcome of spinal fusion with a single Harrington distraction rod in patients with idiopathic scoliosis. At follow-up visits a minimum of 20 years post-surgery, we studied 24 patients who had been operated on by the same surgeon. The Scoliosis Research Society (SRS) Instrument and an additional questionnaire of our own, along with an invitation for a follow-up visit, were originally mailed to 28 consecutive patients of the surgeon. The SRS Instrument has seven domains dealing with back pain, general self-image, self-image after surgery, general function, function in terms of level of activity, function after surgery, and degree of satisfaction with the surgery. The length of time between surgery and the follow-up visit averaged 22.9 years (20.2-27.3). The mean age at surgery and follow-up were 15.8 (13-22) and 38.8 (35-48) years, respectively. Twenty-four patients sent back the completed questionnaires and 16 of them participated in the clinic and radiographic follow-up. To assess the meaning of the questionnaires' results, a control group of the same sex, age and geographic provenance was selected from our outpatients without scoliosis. The average follow-up score on the SRS Instrument for the patients was 100.8 (78-110). When we compared the study and control groups, no significant differences in the single SRS domain scores were observed. The mean Cobb angle and rib cage deformity before surgery were 70.46 degrees (40-120) and 36.4 mm (20-60 mm), respectively, whereas on follow-up they were 41.23 degrees (16-75) and 22.3 mm (5-50 mm), respectively. These long-term results lead us to consider Harrington fusion a procedure that produces a long-lasting high degree of self-reported post-operative satisfaction.