Neutrophil Extracellular Trap-related Biomarkers Are Increased in the Synovial Fluid of Patients With Periprosthetic Joint Infections.

BACKGROUND: The diagnosis of periprosthetic joint infection (PJI) is a major challenge in clinical practice. The role of neutrophils in fighting infection has been increasingly understood, and one mechanism of action of these cells is neutrophil extracellular traps. However, little is known about this process in PJI. QUESTIONS/PURPOSES: (1) Are the biomarkers of neutrophil extracellular trap formation (citrullinated histone H3 [H3Cit], cell-free DNA [cf-DNA], and myeloperoxidase [MPO]) increased in the synovial fluid of patients with PJI? (2) What is the diagnostic accuracy of biomarkers of neutrophil extracellular trap formation for PJI? METHODS: Between May 2020 and March 2021, 43 patients who underwent revision THA or TKA were enrolled in this study. Eleven patients were excluded and 32 patients were categorized into the PJI group (n = 16) or non-PJI group (n = 16) according to the 2018 Second International Consensus Meeting on Musculoskeletal Infection criteria. There were 15 men and 17 women in this study, with a median (range) age of 70 years (60 to 80 years). Twenty-seven patients had TKA and five had THA. We measured cf-DNA, MPO, and H3Cit in synovial fluid. The sensitivity, specificity, and receiver operating characteristic curve were calculated for each biomarker using the Musculoskeletal Infection Society criteria as the gold standard for diagnosis and considering a clinical surveillance of 2 years for patients in the non-PJI group. RESULTS: Patients with PJI had higher levels of synovial fluid cf-DNA (median [range] 130 ng/µL [18 to 179] versus 2 ng/µL [0 to 6]; p < 0.001), MPO (1436 ng/µL [55 to 3996] versus 0 ng/µL [0 to 393]; p < 0.001), and H3Cit (2115 ng/µL [5 to 2885] versus 3 ng/µL [0 to 87]; p < 0.001) than those in the non-PJI group. In receiver operating characteristic curve analyses, we observed near-perfect performance for all biomarkers evaluated, with an area under the curve of 1 (95% CI 0.9 to 1), 0.98 (95% CI 0.9 to 1), and 0.94 (95% CI 0.8 to 0.99) for cf-DNA, MPO, and H3Cit, respectively. The sensitivity for detecting PJI using synovial fluid was 100% for cf-DNA, 94% for MPO, and 88% for H3Cit. The specificity was 100% for cf-DNA and MPO, and 88% for H3Cit. CONCLUSION: Our results show that neutrophils in the periprosthetic microenvironment release neutrophil extracellular traps as part of the bactericidal arsenal to fight infection. These results allow a better understanding of the cellular and molecular processes that occur in this microenvironment, enabling the design of more assertive strategies for identifying new biomarkers and improving the available ones. Novel studies are needed to define whether and how neutrophil extracellular trap-related biomarkers can be useful for diagnosing PJI. LEVEL OF EVIDENCE: Level II, diagnostic study.

Equal rates of bone healing and reduced surgical time with iliac crest allograft compared to autograft in medial opening wedge high tibial osteotomy: a randomized controlled clinical trial.

INTRODUCTION: Iliac crest autograft is frequently used to fill in bone defects after osteotomies. Nonetheless, surgery for bone autograft procurement is associated with morbidity and pain at the donor site. Alternatives to it have been explored, but there is no consensus to guide their application as a routine practice in several orthopedic procedures. Thus, this study was designed to compare the efficacy and safety between iliac crest autograft and allograft in medial opening wedge high tibial osteotomy. MATERIALS AND METHODS: Forty-seven patients with a symptomatic unilateral genu varum and an indication for high tibial osteotomy were randomly assigned to receive either autograft or allograft to fill the osteotomy site. Operative time, bone healing, and complication rates (delayed union, nonunion, superficial and deep infection, loss of correction, and hardware failure) were recorded after a one-year follow-up. Data were expressed as Mean ± Standard Deviation and considered statistically significant when p < 0.05. RESULTS: The time to radiologic union was similar between both groups (Allograft: 2.38 ± 0.97 months vs. Autograft: 2.45 ± 0.91 months; p = 0.79). Complication rates were also similar in both groups, with one infection in the allograft group and two in the autograft group, two delayed unions in the allograft group, and three in the autograft group. The operative time differed by 11 min between the groups, being lower in the allograft group (Allograft: 65.4 ± 15.1 min vs. Autograft: 76.3 ± 15.2 min; p = 0.02). CONCLUSION: Iliac crest allografts can be safely and effectively used in medial opening wedge high tibial osteotomy as it promotes the same rates of bone union as those achieved by autologous grafts, with the benefits of a shorter operative time. TRIAL REGISTRATION NUMBER: U1111-1280-0637 1 December 2022, retrospectively registered.

Cell-free Deoxyribonucleic Acid: A Potential Biomarker of Chronic Periprosthetic Knee Joint Infection.

BACKGROUND: The correct diagnosis of a chronic periprosthetic joint infection (PJI) is a major challenge in clinical practice, with the "gold standard" for diagnosis yet to be established. Synovial fluid analysis has been proven to be a useful tool for that purpose. Cell-free DNA (cf-DNA) levels have been shown to be increased in several conditions such as cancer, trauma, and sepsis. Therefore, this study was designed to evaluate the potential of synovial fluid cf-DNA quantification for the diagnosis of chronic periprosthetic infections following total knee arthroplasty. METHODS: A prospective study with patients undergoing total knee arthroplasty revision surgery for any indication was performed. PJI diagnosis was defined according to the Second International Consensus Meeting on Musculoskeletal Infection (2018) criteria. The study cohort consisted of 26 patients classified as infected and 40 as noninfected. Synovial fluid cf-DNA direct quantification by fluorescent staining was made. Sensitivity, specificity, and receiver operating characteristic curve were calculated. RESULTS: The cf-DNA levels were significantly higher in patients who had PJIs (122.5 ± 57.2 versus 4.6 ± 2.8 ng/µL, P < .0001). With a cutoff of 15 ng/µL, the area under the receiver operating characteristic, sensitivity, and specificity of cf-DNA were 0.978, 96.2%, and 100%, respectively. CONCLUSION: The present study has shown that cf-DNA is increased in synovial fluid of patients who have chronic PJIs. It is a promising biomarker for knee PJI diagnosis and further studies are needed to confirm its utility.

Synovial fluid NMR-based metabolomics in septic and aseptic revision total knee arthroplasty: Implications on diagnosis and treatment.

Periprosthetic joint infection (PJI) is one of the most challenging complications following total knee arthroplasty. Despite its importance, there is a paucity of reports in the literature regarding its pathogenesis. Recently, cellular metabolic reprogramming has been shown to play an important role in the progression and outcome of infectious diseases. Therefore, the aim of this study was to evaluate the metabolites composition of the synovial fluid from patients with PJI or aseptic failure of total knee arthroplasties. The synovial fluids from 21 patients scheduled for revision total knee arthroplasty (11 with the diagnosis of PJI and 10 with aseptic failures) were analyzed using 1D 1H NMR spectroscopy. Univariate and multivariate statistical analyzes were used to identify metabolites that were differentially abundant between those groups. A total of 28 metabolites were identified and five of them found to be differentially abundant between infected and non-infected synovial fluids. Lactate, acetate and 3-hydroxybutyrate were found to be in a higher concentration, and glucose and creatine were found reduced in the synovial fluid from PJI patients. Synovial fluid from patients with PJI exhibit a distinct metabolic profile, possibly reflecting metabolic adaptation that occurs in the infected periprosthetic microenvironment. Further research and studies are warranted to gain a broader insight into the metabolic pathways engaged by both pathogen and immune cells in the context of a PJI.

Microbiological Profile of Periprosthetic Knee Infections in a Brazilian Unified Health System Hospital Specialized in Highly Complex Orthopedic Surgeries.

Objective We studied the microbiological profile of periprosthetic knee infections treated in a Brazilian tertiary hospital. Methods The study included all patients undergoing revision surgery for total knee arthroplasty (RTKA) between November 2019 and December 2021, with a diagnosis of periprosthetic infection confirmed per the 2018 International Consensus Meeting (ICM) criteria. Results Sixty-two patients had a periprosthetic joint infection (PJI) per the 2018 ICM criteria. Cultures were monomicrobial in 79% and polymicrobial in 21% of cases. The most frequent bacterium in microbiological tissue and synovial fluid cultures was Staphylococcus aureus , observed in 26% of PJI patients. Periprosthetic joint infection with negative cultures occurred in 23% of patients. Conclusion Our results show the following: i) a high prevalence of Staphylococcus as an etiological agent for knee PJI; ii) a high incidence of polymicrobial infections in early infections; iii) the occurrence of PJI with negative cultures in approximately one fourth of the subjects.

Accuracy of Serological Markers, Synovial Fluid, Microbiological Culture, and Histopathological Examination for Diagnosing Periprosthetic Knee Infection.

Objective This study assessed the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of serological tests, synovial fluid markers, microbiological tissue culture, and histopathological examination of the periprosthetic membrane in diagnosing periprosthetic knee infection. Methods This study is prospective, and it includes patients undergoing total knee arthroplasty revision surgery from November 2019 to December 2021. The analysis consisted of serological tests (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], and D-dimer), synovial fluid markers (leukocyte and polymorphonuclear cell counts), periprosthetic tissue culture, and histopathological examination of the periprosthetic membrane of all patients. Results Sixty-two patients had periprosthetic joint infection (PJI) according to the 2018 International Consensus Meeting criteria (infection group), while 22 subjects had no infection. ESR sensitivity and specificity were 83.6% and 45.4%, respectively. CRP sensitivity and specificity were 64.5% and 100%, whereas D-dimer sensitivity and specificity were 78.9% and 25%, respectively. Leukocyte count sensitivity and specificity were 75.6% and 100%, polymorphonuclear cell count sensitivity and specificity were 33% and 100%, respectively. Periprosthetic tissue culture sensitivity and specificity culture were, respectively, 77.4% and 100%. Histopathological examination sensitivity and specificity were 43.7% and 100%, respectively. Conclusions In our study, the total blood cell count in synovial fluid and microbiological cultures of periprosthetic tissues were the most accurate tests for PJI diagnosis. In contrast, polymorphonuclear cell percentage was the least accurate test for PJI diagnosis.

EXTENSOR MECHANISM TRANSPLANTATION AFTER KNEE PROSTHESIS: 70-MONTH FOLLOW-UP.

Objective: This article reports the range of motion, failure rate, and complications of patients with extensor mechanism injury after total knee arthroplasty (TKA) treated with extensor mechanism allograft with mid-term follow-up. Methods: Patients undergoing post-ATJ extensor mechanism transplantation from 2009 to 2018 were retrospectively evaluated. Demographics, the reason for transplantation, elapsed time from arthroplasty to transplantation, related surgical factors, immobilization time, range of motion, transplant failure, and complications were collected. The minimum follow-up was 24 months. Results: Twenty patients were evaluated. The mean follow-up was 70.8 +/- 33.6 months. The most common cause of extensor mechanism rupture was traumatic in 10 (50%) cases. Six patients underwent associated surgeries, one case of medial ligament complex reconstruction, and 5 cases of TKA revision. Eleven patients (55%) had transplant-related complications. The most common complication was an infection. Five cases presented transplant failure. Conclusion: Patients who underwent extensor mechanism allograft transplantation after total knee arthroplasty had a 25% failure rate with a mean follow-up of 6 years. Although there was no loss of flexion with the procedure and prolonged immobilization, the complication rate was not low. Level of evidence IV; case series .

Objetivo: O objetivo do estudo foi relatar amplitude de movimento, taxa de falha e complicações de pacientes com lesão do mecanismo extensor após artroplastia total do joelho (ATJ) tratados com aloenxerto do mecanismo extensor com acompanhamento no médio prazo. Métodos: Pacientes submetidos a transplante de mecanismo extensor pós-ATJ de 2009 a 2018 foram avaliados retrospectivamente. Foram avaliados dados demográficos, motivo do transplante, tempo decorrido da artroplastia ao transplante, fatores cirúrgicos relacionados, tempo de imobilização, arco de movimento, falha do transplante e complicações. O acompanhamento mínimo foi de 24 meses. Resultados: Vinte pacientes foram avaliados. O tempo médio de acompanhamento foi de 70,8 +/- 33,6 meses. A causa mais comum de ruptura do mecanismo extensor foi traumática em 10 (50%) casos. Seis pacientes foram submetidos a cirurgias associadas, um caso de reconstrução do complexo ligamentar medial e 5 casos de revisão de ATJ. Onze pacientes (55%) tiveram complicações relacionadas ao transplante. A complicação mais comum foi a infecção. Cinco casos apresentaram falha do transplante. Conclusão: Pacientes submetidos a transplante de aloenxerto de mecanismo extensor após artroplastia total de joelho apresentam taxa de falha de 25% com seguimento médio de 6 anos. Embora não tenha havido perda de flexão com o procedimento e com a imobilização prolongada, o índice de complicações não foi baixo. Nível de evidênvia IV; série de casos .

Midterm Radiographic Results and Reoperations of Tantalum Trabecular Metal Cones in Knee Arthroplasties.

Objective The management of bone loss represents a challenge in revisions of total knee arthroplasty (rTKA) and in complex primary total knee arthroplasties (TKAs). The purpose of the present study was to evaluate the midterm outcomes (5-year minimum follow-up) of knee reconstructions with tantalum trabecular metal (TM) cones on bone defects Anderson Orthopaedics Research Institute (AORI) 2 and 3. Materials and Methods A retrospective analysis of the medical records of patients operated on between July 2008 and November 2014 was performed, collecting the following data: age, gender, laterality, body mass index, etiology of arthrosis, comorbidities, AORI classification of bone defects, causes for revision, readmissions, reoperations, perioperative and postoperative complications, radiographic signs of osteointegration, and maintenance of the TM support. Results A total of 11 patients with a mean follow-up of 7.28 years (standard deviation [SD] = 1.88; range = 5.12-10 years) was evaluated, with 1 patient operated upon for a primary arthroplasty, 6 for revision arthroplasties, and 4 for a second revision arthroplasty (re-revision). There were complications with the surgical wound, injury to the extensor mechanism and loosening of the femoral component in three of the patients that led to the necessity of four procedures due to complications with the surgical wound, injury to the extensor mechanism and loosening of the femoral component. Radiological signs of osteointegration of the trabecular cones were observed in all patients. We did not observe migration of the TM cones or the prosthetic components in the sample. Conclusion The tantalum metaphyseal cones were able to provide efficient structural support to prosthetic implants with radiographic signs of osteointegration in the medium term.

STUDY BETWEEN SEMI-CONSTRAINED TOTAL KNEE ARTHROPLASTY WITH OR WITHOUT INTRAMEDULLARY STEM.

Objective: This research sought to carry out a comparative study observing the clinical and radiographic analysis of primary prostheses of the type TC3 Depuy Johnson® with or without a stem during a short-term follow-up. Methods: The sample was divided into three groups: Group 1 (with stem), Group 2 (without stem) and Group 3 (mixed). Patients were evaluated to assess whether the implants were loosening and a clinical analysis was performed. Results: Preoperative deformities were predominantly considered severe. The total range of motion in the postoperative period was above 96.7° in the three groups. In the postoperative period, the femoral-tibial angle oscillated on average between 5 to 6° valgus. There was no record of implant loosening for cases treated with stem, and the incidence of loosening was 14.3% for the group without stem and 16.7% among cases in the mixed group. Conclusion: In general, preoperative deformities were considered severe. In the postoperative period, the total range of motion was above 96.7°. The postoperative femoral-tibial angle obtained an average of 5 to 6° valgus. There is no significant difference in implants loosening in the three groups. Level of Evidence III, Retrospective Comparative Study.

Objetivo: Realizar um estudo comparativo observando a análise clínica e radiográfica das próteses primárias do tipo TC3 Johnson ® com ou sem haste durante um seguimento de curto prazo. Métodos: A amostra foi dividida em três grupos: Grupo 1 com haste, Grupo 2 sem haste e Grupo 3 misto. Foi realizada a análise clínica dos pacientes e verificado se ocorreu soltura dos implantes. Resultados: As deformidades pré-operatórias foram predominantemente graves. O arco de movimento total no pós-operatório foi acima de 96,7° nos três grupos. No pós-operatório o ângulo tíbio-femoral oscilou na média entre 5 e 6° de valgo. Não houve registro de soltura do implante para os casos tratados com haste; a incidência de soltura foi de 14,3% entre os casos do grupo sem haste e de 16,7% entre os casos do grupo misto. Conclusão: Em geral, as deformidades pré-operatórias foram consideradas graves. No pós-operatório a amplitude total do arco de movimento foi acima de 96,7°. O ângulo tíbio-femoral pós-operatório obteve uma média entre 5 e 6° de valgo. Não há diferença significativa na soltura dos implantes nos três grupos. Nível de Evidência III, Estudo Retrospectivo Comparativo.

Bone Defects in Revision Total Knee Arthroplasty.

The increase in the number of revision total knee arthroplasty surgeries has been observed in recent years, worldwide, for several causes. In the United States, a 601% increase in the number of total knee arthroplasties, between 2005 and 2030, is estimated. Among the enormous challenges of this complex surgery, the adequate treatment of bone defects is essential to obtain satisfactory and lasting results. The adequate treatment of bone defects aims to build a stable and lasting support platform for the implantation of the definitive prosthetic components and, if possible, with the reconstruction of bone stock. Concomitantly, it allows the correct alignment of the prosthetic and limb components, as well as restoring the height of the joint interline and, thus, restoring the tension of soft parts and load distribution to the host bone, generating a joint reconstruction with good function, stable, and painless. There are several options for the management of these bone defects, among them: bone cement with or without reinforcement with screws, modular metallic augmentations, impacted bone graft, structural homologous graft and, more recently, metal metaphyseal cones, and metaphyseal sleeves. The objective of the present article was to gather classic information and innovations about the main aspects related to the treatment of bone defects during revision surgeries for total knee arthroplasty.

Predictive Factors for Blood Transfusion after Total Knee Arthroplasty.

Objectives The present paper aims to (1) verify the incidence and volume of blood transfusion among patients undergoing unilateral cemented total knee arthroplasty (TKA) in a single Brazilian reference center; (2) identify pre and perioperative variables to determine subjects with higher risk (i.e., predictive factors) for blood transfusion within 48 hours following surgery; (3) estimate the risk of blood transfusion during the first 48 hours after the procedure. Methods The initial sample consisted of all patients undergoing TKA from August 2010 to August 2013. After applying the exclusion criteria, 234 patients aged 30 to 83 years old and diagnosed with primary or secondary osteoarthritis due to rheumatoid arthritis remained in the study. Results Preoperative hemoglobin levels ≤ 12.3 g/dL and ischemia time ≥ 87 minutes were independent predictors for post-TKA blood transfusion, with a relative risk of 2.48 and 1.78, respectively. Approximately half of the TKA patients (51.3%) presenting these two variables required a blood transfusion. Conclusion The incidence of post-TKA blood transfusion was 33.7%. On average, each transfused patient received 480 mL of packed red blood cells. Preoperative hemoglobin levels ≤ 12.3 g/dL ( p < 0.001) and ischemia time ≥ 87 minutes ( p < 0.047) were independent predictors for blood transfusion in TKA using a pneumatic cuff, with a relative risk of 2.48 and 1.78, respectively. Age, gender, diagnosis, or body mass index were not considered independent predictors for the need for blood transfusion up to 48 hours after the procedure.

Infection after primary total knee arthroplasty: a randomized controlled prospective study of the addition of antibiotics to bone cement.

Objective The present prospective, randomized and controlled study was conducted with 286 patients submitted to primary total knee arthroplasty (TKA) with the objective of evaluating the efficacy of the addition of antibiotics to bone cement as a way to prevent post arthroplasty infection (PAI). Methods The patients were randomized into two groups: bone cement without antibiotic (No ATB, n = 158) or cement with antibiotic (ATB, n = 128), in which 2 g of vancomycin was added to 40 g of cement. The patients were followed up for 24 months after surgery. Results Regarding preoperative demographic data, the distribution of patients between groups was homogeneous ( p < 0.05). In the 24-month period, the overall infection rate was of 2.09% (6/286), with no difference (odds ratio [OR] = 1.636; 95% confidence interval [CI]: 0.294-9.080; p = 0.694) between the ATB group (1.56%; 2/128) and the No ATB group (2.53%; 4/158). In the No ATB group, the infection was caused by methicillin-resistant Staphylococcus aureus (MRSA) ( n = 2), methicillin-sensitive S. aureus (MSSA) ( n = 1) and Eschirichia coli ( n = 1). Proteus mirabilis and MSSA were isolated from patients in the ATB group. Among the comorbidities, all patients with PAI were hypertensive and nondiabetic. Two rheumatoid arthritis patients who developed PAI were from the ATB group. Conclusion The use of cement with ATB reduced the absolute number of infections, but without statistical difference between the groups; thus, routine use should not be encouraged.

How to Perform a Giant Parameniscal Cyst Exeresis: Step by Step Technique.

Parameniscal cysts are usually small cystic lesions, less than 2 cm in size, found along the meniscal periphery. They are rarely associated with extra-articular palpable mass. Magnetic resonance imaging is the diagnostic method of choice; giant meniscal cysts (>5 cm at its greatest diameter) are very rare, with few cases described in the literature. We describe a step-by-step open exeresis and arthroscopic meniscal suture technique for the treatment of a 9-cm giant parameniscal cyst located on the lateral side of the knee. Treatment of giant meniscal lesions requires caution during dissection and exeresis. Because acute meniscal lesions benefit from meniscal suture rather than meniscectomy, horizontal degenerative lesions may also present excellent results with repair techniques. We conclude that the combination of the open excision of the giant cyst with careful dissection and protection of neurovascular structures, combined with the arthroscopic meniscal suture, is a good strategy to approach such lesions.

Surgical Treatment of Chronic Rupture of the Quadriceps Using a Modified Pulvertaft Weave Technique.

The extensor mechanism provides active knee joint extension and stability of the patellofemoral joint. Rupture of the quadriceps tendon, although uncommon, is therefore associated with impairment in knee joint stability and, thus, requires surgical repair. Although various techniques provide excellent clinical outcomes for acute rupture, treatment of chronic rupture remains clinically challenging. We describe our modified technique for quadriceps tendon repair using a semitendinosus tendon autograft, with suturing of the quadriceps tendon stump to the patella via transosseous sutures, wherein the use of allograft and anchors is avoided. Our modified Pulvertaft weave technique is simple and reproducible.

Accuracy of Serological Markers, Synovial Fluid, Microbiological Culture, and Histopathological Examination for Diagnosing Periprosthetic Knee Infection / Acurácia dosmarcadores sorológicos, do líquido sinovial, cultura microbiológica e exame histopatológico para o diagnóstico de infecção periprotética do joelho

Abstract Objective This study assessed the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of serological tests, synovial fluid markers, microbiological tissue culture, and histopathological examination of the periprosthetic membrane in diagnosing periprosthetic knee infection. Methods This study is prospective, and it includes patients undergoing total knee arthroplasty revision surgery from November 2019 to December 2021. The analysis consisted of serological tests (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], and D-dimer), synovial fluid markers (leukocyte and polymorphonuclear cell counts), periprosthetic tissue culture, and histopathological examination of the periprosthetic membrane of all patients. Results Sixty-two patients had periprosthetic joint infection (PJI) according to the 2018 International Consensus Meeting criteria (infection group), while 22 subjects had no infection. ESR sensitivity and specificity were 83.6% and 45.4%, respectively. CRP sensitivity and specificity were 64.5% and 100%, whereas D-dimer sensitivity and specificity were 78.9% and 25%, respectively. Leukocyte count sensitivity and specificity were 75.6% and 100%, polymorphonuclear cell count sensitivity and specificity were 33% and 100%, respectively. Periprosthetic tissue culture sensitivity and specificity culture were, respectively, 77.4% and 100%. Histopathological examination sensitivity and specificity were 43.7% and 100%, respectively. Conclusions In our study, the total blood cell count in synovial fluid and microbiological cultures of periprosthetic tissues were the most accurate tests for PJI diagnosis. In contrast, polymorphonuclear cell percentage was the least accurate test for PJI diagnosis.

Resumo Objetivo avaliar a sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e acurácia dos testes sorológicos, dos marcadores do líquido sinovial, da cultura microbiológica de tecidos e do exame histopatológico da membrana periprotética para o diagnóstico de infecção periprotética do joelho. Métodos estudo prospectivo, com pacientes submetidos à cirurgia de revisão de artroplastia total do joelho no período entre novembro de 2019 e dezembro de 2021. Foi realizado análise do marcadores sorológicos (VHS,PCR e D-dímero), do líquido sinovial (contagem de leucócitos e percentual de polimorfonucleares), cultura de tecidos periprotéticos e exame histopatológico da membrana periprotética de todos os pacientes. Resultados 62 pacientes foram diagnosticados com infecção periprotética do joelho, pelos critérios do International Consensus Meeting 2018 (grupo infecção) e 22 pacientes integraram o grupo não infecção. A sensibilidade e especificidade da VHS foram de 83,6% e 45,4%, respectivamente. Os valores de sensibilidade e especificidade da PCR foram de 64,5% e 100% e as do D-dímero foram de 78,9%% e 25%, respectivamente. A sensibilidade e especificidade da contagem de leucócitos foi de 75,6% e 100%, e a do percentual de polimorfonucleares foi de 33% e 100%, respectivamente. A sensibilidade e especificidade das culturas de tecidos periprotéticos foi de, respectivamente, 77,4% e 100% A sensibilidade do exame histopatológico foi de 43,7% e a especificidade de 100%. Conclusões A contagem total de leucócitos no líquido sinovial e as culturas microbiológicas dos tecidos periprotéticos foram os testes de maior acurácia para o diagnóstico de infecção periprotética em nossa série. O percentual de polimorfonucleares foi o teste de menor acurácia, em nosso estudo, para o diagnóstico de infecção periprotética.

Total knee arthroplasty in patients with permanent patella dislocation. Report of two cases and literature review.

The occurrence of permanent patellar dislocation associated with severe osteoarthritis is considered rare and difficult to treat. Literature: The literature is quite controversial on the subject. The objective of the study is to report two rare cases of severe osteoarthritis with permanent dislocation of the patella that underwent total knee arthroplasty, in addition to a review of the literature on the subject and related surgical technique. Total knee arthroplasty with using the medial parapatellar approach associated with lateral release was a good surgical option in patients with permanent patellar dislocation associated with advanced osteoarthritis.

A ocorrência de luxação permanente da patela associada a osteoartrite grave é considerada rara e de tratamento difícil. A literatura é bastante controversa sobre o assunto. O objetivo do trabalho é relatar dois raros casos de osteoartrite grave com luxação permanente da patela que foram submetidos a artroplastia total do joelho, além da técnica cirúrgica relacionada e de uma revisão da literatura. A artroplastia total do joelho com o acesso parapatelar medial associado a uma liberação lateral foi uma boa opção cirúrgica em pacientes com luxação permanente da patela associada a osteoartrite avançada.

Microbiological Profi le of Periprosthetic Knee Infections in a Brazilian Unified Health System Hospital Specialized in Highly Complex Orthopedic Surgeries / Perfil microbiológico das infecções periprotéticas do joelho em um hospital do Sistema Único de Saúde especializado em cirurgias ortopédicas de alta complexidade

Abstract Objective We studied the microbiological profile of periprosthetic knee infections treated in a Brazilian tertiary hospital. Methods The study included all patients undergoing revision surgery for total knee arthroplasty (RTKA) between November 2019 and December 2021, with a diagnosis of periprosthetic infection confirmed per the 2018 International Consensus Meeting (ICM) criteria. Results Sixty-two patients had a periprosthetic joint infection (PJI) per the 2018 ICM criteria. Cultures were monomicrobial in 79% and polymicrobial in 21% of cases. The most frequent bacterium in microbiological tissue and synovial fluid cultures was Staphylococcus aureus, observed in 26% of PJI patients. Periprosthetic joint infection with negative cultures occurred in 23% of patients. Conclusion Our results show the following: i) a high prevalence of Staphylococcus as an etiological agent for knee PJI; ii) a high incidence of polymicrobial infections in early infections; iii) the occurrence of PJI with negative cultures in approximately one fourth of the subjects.

Resumo Objetivo Identificar o perfil microbiológico das infecções periprotéticas do joelho tratadas em um hospital terciário brasileiro. Métodos Todos os pacientes submetidos à cirurgia de revisão de artroplastia total do joelho (RATJ), no período compreendido entre novembro de 2019 e dezembro de 2021, e que tiveram o diagnóstico de infecção periprotética confirmado de acordo com critérios do International Consensus Meeting (ICM) 2018, foram incluídos no estudo. Resultados Sessenta e dois pacientes foram diagnosticados com infecção periprotética (IAP) pelos critérios do International Consensus Meeting 2018. Culturas monomicrobianas foram identificadas em 79% e polimicrobianas em 21% dos casos. A bactéria mais frequentemente identificada nas culturas microbiológicas de tecidos e líquido sinovial foi o Staphylococcus aureus, presente em 26% dos pacientes com infecção periprotética. Infecções periprotéticas com culturas negativas ocorreram em 23% dos pacientes. Conclusão Nossos resultados evidenciam: i) alta prevalência de bactérias do gênero Staphylococcus como causadores da IAP do joelho; ii) a alta incidência de infecções polimicrobianas nas infecções precoces e iii) IAP com culturas negativas ocorre em, aproximadamente, um quarto dos pacientes.

LATE EVALUATION OF PATIENTS UNDERGOING MANIPULATION OF THE KNEE AFTER TOTAL ARTHROPLASTY.

OBJECTIVE: We compared gains in range of motion in patients who underwent manipulation within 12 weeks of total knee arthroplasty (TKA) and after this period. We also evaluated maintenance of the arc obtained from knee manipulation in late follow-up, along with factors associated with poorer outcomes. METHOD: The study was divided into two groups according to the time after TKA; the surgeries took place between January 2008 and December 2014. RESULTS: When comparing the range of motion between early and late manipulations, the group that underwent manipulation within 12 weeks of the TKA exhibited better outcomes, but these were not statistically significant. We observed that 14.3% of cases retained the same range attained at the time of manipulation. In late evaluation after manipulation, 47.7% of the sample had a range of less than 90 degrees. The significant risk factors for recurrence of knee stiffness in the long term are poor range of motion before TKA and before manipulation, female sex, and secondary arthritis. CONCLUSION: Women previously diagnosed with secondary osteoarthritis and poor range of motion before TKA or manipulation are at higher risk for late stiffness. Level of Evidence III, Retrospective Comparative Study.

OBJETIVO: Comparar o ganho de arco de movimento entre os pacientes submetidos à manipulação antes de 12 semanas pós-artroplastia total do joelho (ATJ), e depois desse período. Além disso, avaliar tardiamente a manutenção do arco obtido com a manipulação do joelho e fatores relacionados com os piores resultados. MÉTODO: O estudo foi dividido em dois grupos, de acordo com o tempo pós-ATJ. Os procedimentos ocorreram entre janeiro de 2008 e dezembro de 2014. RESULTADOS: Quando comparamos os arcos de movimento entre as manipulações precoces e tardias, o grupo submetido à manipulação em 12 semanas da ATJ apresentou melhores resultados, porém, sem significância estatística. Foi observado que 14,3% dos casos mantiveram a mesma amplitude alcançada no momento da manipulação. Na avaliação tardia, 47,7% da amostra obtiveram amplitude menor que 90 graus. Os fatores de risco significantes para recidiva tardia de rigidez são arco de movimento ruim antes da ATJ e antes da manipulação, sexo feminino e artrites secundárias. CONCLUSÃO: Mulheres com diagnóstico prévio de osteoartrite secundária e com arco ruim antes da ATJ ou da manipulação têm maior risco de rigidez tardia. Nível de Evidência III, Estudo Retrospectivo Comparativo.

Midterm Radiographic Results and Reoperations of Tantalum Trabecular Metal Cones in Knee Arthroplasties / Reoperações e resultados radiográficos de médio prazo do uso de cone de metal trabecular de tântalo nas artroplastias do joelho

Abstract Objective The management of bone loss represents a challenge in revisions of total knee arthroplasty (rTKA) and in complex primary total knee arthroplasties (TKAs). The purpose of the present study was to evaluate the midterm outcomes (5-year minimum follow-up) of knee reconstructions with tantalum trabecular metal (TM) cones on bone defects Anderson Orthopaedics Research Institute (AORI) 2 and 3. Materials and MethodsA retrospective analysis of the medical records of patients operated on between July 2008 and November 2014 was performed, collecting the following data: age, gender, laterality, body mass index, etiology of arthrosis, comorbidities, AORI classification of bone defects, causes for revision, readmissions, reoperations, perioperative and postoperative complications, radiographic signs of osteointegration, and maintenance of the TM support. Results A total of 11 patients with a mean follow-up of 7.28 years (standard deviation [SD] = 1.88; range = 5.12-10 years) was evaluated, with 1 patient operated upon for a primary arthroplasty, 6 for revision arthroplasties, and 4 for a second revision arthroplasty (re-revision). There were complications with the surgical wound, injury to the extensor mechanism and loosening of the femoral component in three of the patients that led to the necessity of four procedures due to complications with the surgical wound, injury to the extensor mechanism and loosening of the femoral component. Radiological signs of osteointegration of the trabecular cones were observed in all patients. We did not observe migration of the TM cones or the prosthetic components in the sample. Conclusion The tantalum metaphyseal cones were able to provide efficient structural support to prosthetic implants with radiographic signs of osteointegration in the medium term.

Resumo Objetivo O manejo da perda óssea representa um grande desafio em cirurgias de revisão de artroplastia do joelho (rATJ) e em artroplastias totais do joelho (ATJ) primárias complexas. O objetivo do presente estudo foi avaliar os resultados em médio prazo (seguimento mínimo de 5 anos) das reconstruções de joelho nas quais cones de metal trabecular (MT) de tântalo foram utilizados para tratamento de defeitos ósseos tipos 2 e 3, de acordo com a classificação proposta pela Anderson Orthopaedic Research Institute (AORI). Métodos Feita análise retrospectiva dos prontuários dos pacientes operados entre julho de 2008 e novembro de 2014, coletando-se os seguintes dados: idade, gênero, lateralidade, índice de massa corporal, etiologia da artrose, comorbidade, classificação AORI da falha óssea, causa da revisão da artroplastia total do joelho, reinternações, reoperações, complicações peri- e pós-operatórias, ocorrência de osteointegração radiográfica e manutenção da função de suporte do MT. Resultados Foram avaliados 11 pacientes com tempo médio de seguimento de 7,28 anos (desvio padrão [DP] = 1,88; variação = 5,12-10 anos), sendo que 1 paciente foi submetido a artroplastia primária, 6 a artroplastia de revisão e 4 a segunda revisão de artroplastia (re-revisão). Três pacientes necessitaram de quatro reoperações devido a complicações com a ferida operatória, a lesão do mecanismo extensor e a soltura do componente femoral. Sinais de osteointegração dos cones trabeculados foram observados em todos os pacientes. Não observamos migração do cone de MT ou dos componentes protéticos. Conclusão Os cones metafisários de tântalo foram capazes de prover suporte estrutural eficiente aos implantes protéticos com sinais radiográficos de osteointegração em médio prazo.

Extensor mechanism transplantation after knee prosthesis: 70-month follow-up / Transplante de mecanismo extensor após prótese de joelho: seguimento 70 meses

ABSTRACT Objective: This article reports the range of motion, failure rate, and complications of patients with extensor mechanism injury after total knee arthroplasty (TKA) treated with extensor mechanism allograft with mid-term follow-up. Methods: Patients undergoing post-ATJ extensor mechanism transplantation from 2009 to 2018 were retrospectively evaluated. Demographics, the reason for transplantation, elapsed time from arthroplasty to transplantation, related surgical factors, immobilization time, range of motion, transplant failure, and complications were collected. The minimum follow-up was 24 months. Results: Twenty patients were evaluated. The mean follow-up was 70.8 +/- 33.6 months. The most common cause of extensor mechanism rupture was traumatic in 10 (50%) cases. Six patients underwent associated surgeries, one case of medial ligament complex reconstruction, and 5 cases of TKA revision. Eleven patients (55%) had transplant-related complications. The most common complication was an infection. Five cases presented transplant failure. Conclusion: Patients who underwent extensor mechanism allograft transplantation after total knee arthroplasty had a 25% failure rate with a mean follow-up of 6 years. Although there was no loss of flexion with the procedure and prolonged immobilization, the complication rate was not low. Level of evidence IV; case series .

RESUMO Objetivo: O objetivo do estudo foi relatar amplitude de movimento, taxa de falha e complicações de pacientes com lesão do mecanismo extensor após artroplastia total do joelho (ATJ) tratados com aloenxerto do mecanismo extensor com acompanhamento no médio prazo. Métodos: Pacientes submetidos a transplante de mecanismo extensor pós-ATJ de 2009 a 2018 foram avaliados retrospectivamente. Foram avaliados dados demográficos, motivo do transplante, tempo decorrido da artroplastia ao transplante, fatores cirúrgicos relacionados, tempo de imobilização, arco de movimento, falha do transplante e complicações. O acompanhamento mínimo foi de 24 meses. Resultados: Vinte pacientes foram avaliados. O tempo médio de acompanhamento foi de 70,8 +/- 33,6 meses. A causa mais comum de ruptura do mecanismo extensor foi traumática em 10 (50%) casos. Seis pacientes foram submetidos a cirurgias associadas, um caso de reconstrução do complexo ligamentar medial e 5 casos de revisão de ATJ. Onze pacientes (55%) tiveram complicações relacionadas ao transplante. A complicação mais comum foi a infecção. Cinco casos apresentaram falha do transplante. Conclusão: Pacientes submetidos a transplante de aloenxerto de mecanismo extensor após artroplastia total de joelho apresentam taxa de falha de 25% com seguimento médio de 6 anos. Embora não tenha havido perda de flexão com o procedimento e com a imobilização prolongada, o índice de complicações não foi baixo. Nível de evidênvia IV; série de casos .