Septic Arthritis and Prosthetic Joint Infections in Older Adults

Burden of surgical management of prosthetic joint infections following hip and knee replacements in Alberta, Canada: an analysis and comparison of two major urban centres

BACKGROUND

Complex surgical site infections (SSIs) and revisions for these infectious complications following total knee and hip arthroplasties are associated with significant economic costs.

AIM

To evaluate the cost of one-stage and two-stage revision; debridement, antibiotics and implant retention (DAIR); and DAIR with liner exchange for complex hip or knee SSIs in Alberta, Canada.

METHODS

The Alberta Health Services Infection Prevention and Control database was used to identify individuals aged ≥18 years from the two major urban centres in Alberta - Calgary and Edmonton - with complex hip or knee SSIs who underwent surgical intervention between 1st April 2012 and 31st March 2019. Micro-costing and gross costing methods were used to estimate 12- and 24-month costs following the initial hospital admission for arthroplasty. Subgroup, inverse Gaussian and gamma regression analyses were used to evaluate associations between cost and revision procedure, age, sex and comorbidities.

FINDINGS

In total, 382 patients with complex SSIs were identified, with a mean age of 66.1 years. DAIR and DAIR with liner exchange resulted in the lowest 12- and 24-month costs at $53,197 [95% confidence interval (CI) $38,006-68,388] and $57,340 (95% CI $48,576-66,105), respectively; two-stage revision was the costliest procedure. Most of the costs incurred (>98%) were accrued within the first 12 months following the initial procedure.

CONCLUSIONS

Medical costs are highest in the 12 months following initial arthroplasty, and for two-stage revision procedures in hip and knee complex SSIs.

Do urinary tract infections affect the rate of periprosthetic joint infections in patients who underwent arthroplasty surgery? A systematic review and meta-analysis

Periprosthetic joint infection (PJI) is a significant issue in orthopedic surgery. Urinary tract infections (UTIs) and asymptomatic bacteriuria (ASB) have been identified as potential causes of PJI; however, evidence is inconclusive. Understanding these relationships is critical for improving therapy and patient outcomes. A systematic review was performed by conducting searches from PubMed, EBSCO, ProQuest, and manual searching with adherence to the Preferred Reporting Items for Systematic Review and Meta-Analysis 2020 guideline. Studies that reported UTI/ASB and PJI were included. Meta-analysis was conducted using a random-effects model using RevMan 5.4 software. A total of 14 studies were included with UTIs and ASB showed an overall association with increased risk of PJI (odds ratio [OR]: 1.84, 95% confidence interval [CI]: 1.14-2.99, P = 0.01). However, subgroup analysis for UTIs and ASB was not significant. Further analysis of UTIs in total hip arthroplasty (THA) surgery showed a significant association (OR: 1.76, 95% CI: 1.57-1.96) with PJI. Preoperative UTIs timing between 0 and 2 weeks before surgery showed an increased risk of PJI (OR: 1.45, 95% CI: 1.35-1.55). Antibiotic treatment in ASB did not significantly impact PJI rates. Urine and PJI sample cultures in four studies showed no correlation of microorganisms between the two sites. According to recent evidence, a statistically significant association was found between UTIs and PJI in patients who underwent THA surgery. However, ASB did not yield significant results in relation to PJI. These results should be supported by larger and well-designed studies to make proper clinical suggestion in future. For further research, it is recommended to adopt standardized criteria for outcome measurement and to involve larger sample sizes to enhance the reliability and generalizability of findings.

Implant retention in a rabbit model of fracture-related infection

Aims

Fracture-related infection (FRI) is commonly classified based on the time of onset of symptoms. Early infections (< two weeks) are treated with debridement, antibiotics, and implant retention (DAIR). For late infections (> ten weeks), guidelines recommend implant removal due to tolerant biofilms. For delayed infections (two to ten weeks), recommendations are unclear. In this study we compared infection clearance and bone healing in early and delayed FRI treated with DAIR in a rabbit model.

Methods

Staphylococcus aureus was inoculated into a humeral osteotomy in 17 rabbits after plate osteosynthesis. Infection developed for one week (early group, n = 6) or four weeks (delayed group, n = 6) before DAIR (systemic antibiotics: two weeks, nafcillin + rifampin; four weeks, levofloxacin + rifampin). A control group (n = 5) received revision surgery after four weeks without antibiotics. Bacteriology of humerus, soft-tissue, and implants was performed seven weeks after revision surgery. Bone healing was assessed using a modified radiological union scale in tibial fractures (mRUST).

Results

Greater bacterial burden in the early group compared to the delayed and control groups at revision surgery indicates a retraction of the infection from one to four weeks. Infection was cleared in all animals in the early and delayed groups at euthanasia, but not in the control group. Osteotomies healed in the early group, but bone healing was significantly compromised in the delayed and control groups.

Conclusion

The duration of the infection from one to four weeks does not impact the success of infection clearance in this model. Bone healing, however, is impaired as the duration of the infection increases.

Global research output and highly-cited publications on prosthetic joint infections: A bibliometric analysis (2003-2022)

Backgroundand aims

Prosthetic Joint Infection (PJI) is a serious clinical problem after Arthroplasty. The research field on PJI is emerging, but there is a paucity of information on the most impactful publications on it. This prompted us to conduct a bibliometric analysis of the global research output, from 2003 to 2022, to identify the growth of publications, the key players in this research field and to evaluate the characteristics of highly-cited publications (HCPs) on the PJI.

Methods

Publications related to PJI research were identified globally from the Scopus database, using specific keywords, covering the literature from 2003 to 2022. The HCPs were considered those with 100 or more citations. Information on publication year, citation count, funding sources, title, author, journal, country, institution, research area, and strategic keywords were collected from these HCPs. Publication data was imported into Microsoft Excel and analyzed further using VOSviewer and R software.

Results

There were 182 HCPs (3.12%), which received a total citation of 124701 (average CPP of 21.41), with the citation range from 100 to 1921. Research articles were the most predominant publications (69.2%), but their average citations per paper (CPP) of 189.78 was lower than that of Review articles (average CPP: 253.17). The USA has been the leading country in terms of total publications (31.58%), and HCPs (36.99%), followed by Switzerland, Spain, UK and China. There were no HCPs from developing countries. J. Parvizi of Thomas Jefferson University, USA (with a total publications of 31 and an average CPP of 315.7), and W. Zimmerli of Basel University, Switzerland (with a TP of 11 and an average CPP of 341.9), were the most productive and impactful authors in PJI global research output.

Conclusion

This bibliometric analysis identified the most productive and impactful authors, organizations, countries, and journals in the research of PJI, of the last two decades.

Comparative bone healing with induced membrane technique (IMT) versus empty defects in septic and aseptic conditions in a novel rabbit humerus model

BACKGROUND

Long bone defects resulting from primary trauma or secondary to debridement of fracture-related infection (FRI) remain a major clinical challenge. One approach often used is the induced membrane technique (IMT). The effectiveness of the IMT in infected versus non-infected settings remains to be definitively established. In this study we present a new rabbit humerus model and compare the IMT approach between animals with prior infection and non-infected equivalents.

METHODS

A 5 mm defect was created in the humerus of New Zealand White rabbits (n = 53) and fixed with a 2.5 mm stainless steel plate. In the non-infected groups, the defect was either left empty (n = 6) or treated using the IMT procedure (PMMA spacer for 3 weeks, n = 6). Additionally, both approaches were applied in animals that were inoculated with Staphylococcus aureus 4 weeks prior to defect creation (n = 5 and n = 6, respectively). At the first and second revision surgeries, infected and necrotic tissues were debrided and processed for bacteriological quantification. In the IMT groups, the PMMA spacer was removed 3 weeks post implantation and replaced with a beta-tricalcium phosphate scaffold and bone healing observed for a further 10 weeks. Infected groups also received systemic antibiotic therapy. The differences in bone healing between the groups were evaluated radiographically using a modification of the radiographic union score for tibial fractures (RUST) and by semiquantitative histopathology on Giemsa-Eosin-stained sections.

RESULTS

The presence of S. aureus infection at revision surgery was required for inclusion to the second stage. At the second revision surgery all collected samples were culture negative confirming successful treatment. In the empty defect group, bone healing was increased in the previously infected animals compared with non-infected controls as revealed by radiography with significantly higher RUST values at 6 weeks (p = 0.0281) and at the end of the study (p = 0.0411) and by histopathology with increased cortical bridging (80% and 100% in cis and trans cortical bridging in infected animals compared to 17% and 67% in the non-infected animals). With the IMT approach, both infected and non-infected animals had positive healing assessments.

CONCLUSION

We successfully developed an in vivo model of bone defect healing with IMT with and without infection. Bone defects can heal after an infection with even better outcomes compared to the non-infected setting, although in both cases, the IMT achieved better healing.

Periprosthetic knee infection in octogenarians: a single institution experience at midterm outcome

PURPOSE

Periprosthetic joint infections (PJI) of total knee arthroplasties (TKAs) in the elderly is among the clinically most challenging scenarios given multimorbidity combined with poor bone and soft tissue quality. Despite increasing prevalence, limited is known on PJI among this unique group of patients. As such, this study analyzed PJI characteristics, implant survivorship and non-surgical complications of octogenarians revised PJI for the knee.

METHODS

We identified 31 patients that were revised for PJIs of the knee between 2010 and 2019 using a single university-based registry. Mean age was 83 years (range 80-87), 48% were females, and mean BMI was 29 kg/m2. Mean age adjusted Charlson Comorbidity Index was 7, and mean ASA score was 3. Major causative pathogens included Coagulase-negative Staphylococci (26%), Staphylococcus aureus (13%), and Streptococci (13%). Two-stage exchange was performed in 30 patients, permanent resection arthroplasty in one joint. Kaplan-Meier survivorship analyses were performed. Mean follow-up was 4 years.

RESULTS

The 2-year survivorship free of any recurrent PJI was 96%, and there was one PJI relapse noted at 6 months. Moreover, there were three additional revisions for aseptic loosening, and one further revision for fracture. As such, the 2-year survivorship free of any revision was 87%. In addition to the aforementioned revisions, there was one additional plate osteosynthesis for a Vancouver C fracture, resulting in a 79% survivorship free of any reoperation at 2 years. Mean perioperative complication score according to the Clavien-Dindo classification was 2 out of 5. A total of three patients died: one patient 40 days after resection arthroplasty, two others 4 months and 8 months after reimplantation.

CONCLUSIONS

Octogenarians revised for PJI of the knee are at low risk of recurrent infection and overall revision at 2 years. However, moderate rates of perioperative complications and mortality at short term must acknowledge before deciding upon procedure.

LEVEL OF EVIDENCE

Therapeutic level IV.

Periprosthetic hip infection in octogenarians : a single institution experience of 33 cases

AIMS

Periprosthetic joint infection (PJI) in total hip arthroplasty in the elderly may occur but has been subject to limited investigation. This study analyzed infection characteristics, surgical outcomes, and perioperative complications of octogenarians undergoing treatment for PJI in a single university-based institution.

METHODS

We identified 33 patients who underwent treatment for PJIs of the hip between January 2010 and December 2019 using our institutional joint registry. Mean age was 82 years (80 to 90), with 19 females (57%) and a mean BMI of 26 kg/m² (17 to 41). Mean American Society of Anesthesiologists (ASA) grade was 3 (1 to 4) and mean Charlson Comorbidity Index was 6 (4 to 10). Leading pathogens included coagulase-negative Staphylococci (45%) and Enterococcus faecalis (9%). Two-stage exchange was performed in 30 joints and permanent resection arthroplasty in three. Kaplan-Meier survivorship analyses were performed. Mean follow-up was five years (3 to 7).

RESULTS

The two-year survivorship free of any recurrent PJI was 72% (95% confidence interval (CI) 56 to 89; 18 patients at risk). There were a total of nine recurrent PJIs at a mean of one year (16 days to eight years), one for the same pathogen as at index infection. One additional surgical site infection was noted at two weeks, resulting in a 69% (95% CI 52 to 86; 17 patients at risk) survivorship free of any infection at two years. There were two additional revisions for dislocations at one month each. As such, the two-year survivorship free of any revision was 61% (95% CI 42 to 80; 12 patients at risk). In addition to the aforementioned revisions, there was one additional skin grafting for a decubitus ulcer, resulting in a survivorship free of any reoperation of 54% (95% CI 35 to 73; ten patients at risk) at two years. Mean Clavien-Dindo score of perioperative complications was two out of five, with one case of perioperative death noted at six days.

CONCLUSION

Octogenarians undergoing surgery for PJI of the hip are at low risk of acute mortality, but are at moderate risk of other perioperative complications. One in two patients will undergo a reoperation within two years, with 70% attributable to recurrent infections.Cite this article: Bone Joint J 2023;105-B(2):135-139.

Septic arthritis induced by Streptococcus pneumoniae occurring in rheumatoid arthritis treated with abatacept and methotrexate: A case report

Septic arthritis occurs more frequently in elderly patients with rheumatoid arthritis (RA), with Staphylococcus aureus being the most common aetiologic agent. Rarely, Streptococcus pneumoniae (pneumococcus) is the cause of septic arthritis. Biological disease-modifying antirheumatic drugs (bDMARDs) are widely used in RA, but it is unknown whether bDMARDs could be a risk factor for pneumococcal septic arthritis in such patients. Here, we report the case of a patient with RA treated with bDMARDs (abatacept) who developed pneumococcal septic arthritis. The patient is a 64-year-old female complicated with RA for >10 years. She was treated with abatacept and methotrexate and has been in remission for 2 years. She had not received any pneumococcal vaccination. She consulted at our hospital for left ankle arthralgia and fever. Blood culture and puncture of the left ankle joints detected pneumococcus, and the pneumococcal urine antigen test was positive. The patient was diagnosed with pneumococcal septic arthritis, and she recovered after the administration of antibiotics. This is the first case report discussing these circumstances, suggesting that bDMARDs may be a risk of pneumococcal septic arthritis in patients with RA. To prevent this, pneumococcal vaccination should be encouraged in such patients. Furthermore, if RA is in remission, we may consider the spacing or withdrawal of bDMARDs to avoid severe infection.

Prosthetic Joint Infections of the Hip and Knee Among the Elderly: A Retrospective Study

BACKGROUND

As the population ages and demand for total joint arthroplasty increases, rates of periprosthetic joint infection are expected to increase in the geriatric population. Studies comparing prevalence of risk factors, etiology, management, and mortality of prosthetic joint infection in older patients are lacking.

METHODS

We compared clinical characteristics, management, and mortality of patients <75 vs ≥75 years of age with first prosthetic joint infection of the hip or knee admitted to a tertiary medical center between September 2017 and December 2019.

RESULTS

Ninety-eight patients (<75 years of age [n = 63]; ≥75 years of age (n = 35) were studied. Groups were similar in terms of etiology, culture-directed therapy, antibiotic suppression, and length of stay. There was no difference in surgical management, performed in almost 97% of cases in both groups. Arrhythmia and heart failure were more prevalent in those aged ≥75 years. Readmission related to prosthetic joint infection occurred less often in older individuals (P = .005). Deaths within 1 year of diagnosis were rare (n = 4; 4.1%), occurring in older patients and resulting mostly from sepsis.

CONCLUSION

In our single-center study, patients with first prosthetic joint infection had similar management, regardless of age. We identified cardiac history as one of the host factors for prosthetic joint infection most seen in patients ≥75 years of age. Although deaths were rare, 1-year mortality was higher in patients aged ≥75. Prospective, multicenter studies are needed to explore risk factors and management strategies of prosthetic joint infection among elderly populations.

Concurrent targeting of glycolysis in bacteria and host cell inflammation in septic arthritis

Intracellular infiltration of bacteria into host cells complicates medical and surgical treatment of bacterial joint infections. Unlike soft tissue infections, septic arthritis and infection-associated inflammation destroy cartilage that does not regenerate once damaged. Herein, we show that glycolytic pathways are shared by methicillin-resistant Staphylococcus aureus (MRSA) proliferation and host inflammatory machinery in septic arthritis. MRSA readily penetrates host cells and induces proinflammatory cascades that persist after conventional antibiotic treatment. The glycolysis-targeting drug dimethyl fumarate (DMF) showed both bacteriostatic and anti-inflammatory effects by hindering the proliferation of intracellular MRSA and dampening excessive intraarticular inflammation. Combinatorial treatment with DMF and vancomycin further reduced the proliferation and re-emergence of intracellular MRSA. Combinatorial adjuvant administration of DMF with antibiotics alleviated clinical symptoms of septic arthritis by suppressing bacterial burden and curbing inflammation to protect cartilage and bone. Our results provide mechanistic insight into the regulation of glycolysis in the context of infection and host inflammation toward development of a novel therapeutic paradigm to ameliorate joint bioburden and destruction in septic arthritis.

Role of Biomarkers in Periprosthetic Joint Infections

Periprosthetic joint infection (PJI) is one of the most serious complications after joint arthroplasty. The incidence rate of PJI after total joint replacement is 1-3%. Although there are different guidelines and diagnostic criteria used to diagnose PJI, diagnosing PJI is a highly difficult process for orthopedists. The current Musculoskeletal Infection Society (MSIS) criteria are widely used for the diagnosis of PJI. These criteria include results from blood/synovial fluid tests, physical examination, and histological and microbiological analyses of intra-operative samples. However, there is currently no blood or synovial test that can definitively diagnose PJI. To make a more effective diagnosis of PJI, a large number of studies have explored and continue to investigate biomarkers. This review aims to provide general information about serum and synovial markers used for the diagnosis of PJI that may be used to create a database to guide researchers in new studies.

Septic arthritis of the hand: From etiopathogenesis to surgical treatment

BACKGROUND

Septic arthritis of the hand, which is the second most common after damage of the knee joint, remains one of the leading causes of temporary disability. An inflammation can cause dysfunction of the joint, and in the most severe cases, the need for amputation of the finger may arise. The results of their treatment today, especially from a functional point of view, cannot be considered satisfactory. Urgent surgical treatment is extremely important in septic arthritis of the hand, as it helps to prevent cartilage destruction and the development of osteomyelitis.

AIM

To explore the features of the course of septic arthritis of the hand as well as approaches to surgical treatment and its results, depending on the nature of the damage to the articular structures.

METHODS

The results of the treatment of 170 patients with septic arthritis of the hand, which were treated in the period of 2020-2021, were analyzed. Inflammation of the interphalangeal and metacarpophalangeal joints (MCP) of fingers 1, 2, and 3 was more often noted in 147 (81.6%) joints. The most common cause of arthritis was a penetrating injury as a result of household trauma (101, 59.4%), animal bite (30, 17.6%), and clenched fist injury (15, 8.8%). Septic arthritis with contiguous osteomyelitis was observed in 98 (54.4%) cases. Surgical treatment was completed with drainage and irrigation of the joint. Early mobilization was used to restore function. In patients with osteomyelitis, it was aimed at the formation of neoarthrosis. Arthrodesis was not applied. Long-term results of treatment were assessed in 142 (83.5%) patients within 1 mo to 12 mo after discharge from the hospital [the median was 7 mo (IQR: 4-9)].

RESULTS

The most commonly isolated organism was Staphylococcus aureus (35.3%). The median treatment delay in patients without osteomyelitis was 5 d (IQR: 4-7); for septic arthritis with contiguous osteomyelitis, it was 14 d (IQR: 5-21). Radiography for osteomyelitis within 2 wk was uninformative: 41.2% of diagnoses. A single surgical treatment was required in 138 (81.2%) patients, two treatments in 22 (12.9%), and three or more in 10 (5.9%). Total elimination of the infection was achieved in 163 (95.9%) patients. The best functional results of treatment were noted in patients without osteomyelitis. After septic arthritis, Total Active Motion (TAM) for the MCP was 96.2% (IQR: 85.1-98.0), for the proximal interphalangeal joint (PIP) 82.4% (IQR: 54.5-98.5), and for the distal interphalangeal joint (DIP) 69.4% (IQR: 65.4-74.1). In cases with osteomyelitis, it was possible to achieve the formation of neoarthrosis with TAM for MCP-64.2% (IQR: 45.3-90.1), for PIP-62.5% (IQR: 41.8-68.9), and for DIP-59.4% (IQR: 50-62.1). Additionally, the severity of pain during movements did not exceed 1 point.

CONCLUSION

The delay in treatment of patients with septic arthritis of the hand was accompanied by a high incidence of osteomyelitis, especially in the presence of diabetes mellitus. Urgent surgical treatment, along with continued irrigation of the joint and antibiotic therapy, made it possible to eliminate the infection, and early rehabilitation restored the range of motion. The best results were noted in patients without osteomyelitis. With the development of osteomyelitis, a complex of early rehabilitation measures also made it possible to partially restore the range of motion due to the formation of neoarthrosis, without resorting to arthrodesis.

Implant surface modifications as a prevention method for periprosthetic joint infection caused by Staphylococcus aureus: a systematic review and meta-analysis

Abstract. Background: Periprosthetic joint infection is the most common infection due to joint replacement. It has been reported that, over a 5-year time span, 3.7 % of cases occurred annually. This statistic has increased to 6.86 % over 16 years. Thus, an effective method is required to reduce these complications. Several strategies such as coating methods with various materials, such as antibiotics, silver, and iodine, have been reported. However, the best preventive strategy is still undetermined. Therefore, this systematic review aims to evaluate the outcome of coating methods on joint arthroplasty as a treatment or preventive management for infection complications. Methods: Eligible articles were systematically searched from multiple electronic databases (PubMed, Cochrane library, and ScienceDirect) up to 2 June 2022. Based on the criterion inclusion, eight articles were selected for this study. The Newcastle–Ottawa scale (NOS) was used to assess the quality of the study, and the meta-analysis test was conducted with Review Manager 5.4. Results: The quality of the articles in this study is in the range of moderate to good. It was found that the application of modified antibiotic coatings significantly reduced the occurrence of periprosthetic joint infection (PJI) (p 0.03), and silver coating could not significantly (p 0.47) prevent the occurrence of PJI. However, according to the whole aspect of coating modification, the use of antibiotics, silver, and iodine can minimize the occurrence of PJI (p <0.0001). Conclusion: Coating methods using antibiotics are an effective method that could significantly prevent the occurrence of PJI. On the other hand, coating with non-antibiotic materials such as silver could not significantly prevent the incidence of PJI.

Septic arthritis of shoulder joint following a COVID-19 vaccination: A case report

Introduction

Septic arthritis of the shoulder joint is a serious condition which requires early diagnosis and treatment. This condition usually presents with shoulder pain, limited range of motion and/or fever, and is diagnosed by shoulder arthrocentesis with significant synovial fluid leukocytosis or positive synovial fluid gram stain or culture. There are some risk factors for septic arthritis, notably bacteremia, pre-existing joint pathology and an immunocompromised host such as poorly controlled type II diabetes mellitus.

Case presentation

A 45-year-old Thai female developed left shoulder septic arthritis after an Astra-Zeneca COVID-19 vaccine administration. The clinical symptoms were left shoulder pain, limited range of motion and fever. The probable risk factors were underlying diabetes mellitus type II and vaccine administration technique. The joint fluid culture showed Staphylococcus aureus. This patient was treated with combined arthroscopic debridement and an intravenous antibiotic for 1 week which was then switched to an oral antibiotic for 5 weeks. Her clinical symptoms gradually improved over the 2 weeks following the initiation of treatment.

Conclusion

Septic arthritis is a rare complication after a vaccination. Doctors should be especially careful with immunocompromised patients, and always use a correct injection technique.

•

Septic arthritis of the shoulder should not be missed in the patient with shoulder pain after vaccination.

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Even through the type II diabetes mellitus was well-controlled, the type II diabetes mellitus still placed her at extra risk of septic arthritis.

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The other possible cause was the injection technique of the vaccination.

ACUTE DESTRUCTIVE HIP SEPTIC ARTHRITIS IN A YOUNG ADULT PATIENT: CASE REPORT (v2)

The Authors describe a case of rapid right hip destructive septic arthritis in a 50-year-old male patient with no previous noteworthy medical history. Patient arrived to our attention following a one week history of right hip pain. Laboratory markers and imaging at presentation were negative. However, on a follow-up examination significant joint effusion was noted and joint tap was performed. Despite wide spectrum antibiotic therapy institution, significant joint damage was observed. This required surgical femoral head excision with antibiotic loaded spacer, followed by hip arthroplasty surgery 12 weeks afterwards. Complete healing of the infection and recovery of pain-free joint motion was noted at 1 year follow-up.

Molecular Approach for the Laboratory Diagnosis of Periprosthetic Joint Infections

The incidence of total joint arthroplasty is increasing over time since the last decade and expected to be more than 4 million by 2030. As a consequence, the detection of infections associated with surgical interventions is increasing and prosthetic joint infections are representing both a clinically and economically challenging problem. Many pathogens, from bacteria to fungi, elicit the immune system response and produce a polymeric matrix, the biofilm, that serves as their protection. In the last years, the implementation of diagnostic methodologies reduced the error rate and the turn-around time: polymerase chain reaction, targeted or broad-spectrum, and next-generation sequencing have been introduced and they represent a robust approach nowadays that frees laboratories from the unique approach based on culture-based techniques.

Septic arthritis of the hand: Current issues of etiology, pathogenesis, diagnosis, treatment

Septic arthritis of the hand is a serious disease that often results in dysfunction of the joint or even the need to perform amputation of the finger. They rank second in the frequency of occurrence after lesions of the knee joint. Many points concerning the etiology, the timing of the development of cartilage destruction and the development of osteomyelitis, approaches to surgical treatment, the duration of antibiotic therapy, and the start of rehabilitation measures remain the subject of numerous discussions. Based on a search in the PubMed, Web of Science and Google Scholar databases down to 1990-2021, publications on septic arthritis of the hand were found and analyzed. The following inclusion criteria were used in our review: (1) Septic arthritis of the hand; (2) Published in a peer review journal; (3) Written in English; and (4) Full text version available. Studies were excluded if they met any of the following criteria: (1) Letters; (2) Articles published in abstract form only; and (3) Cadaveric studies. Septic arthritis of the hand was characterized by the most frequent damage to the joints of the index and middle fingers (> 50% of cases). Up to 90% of cases, the infection enters the joint as a result of penetrating trauma, animal bites, etc. Staphylococcus aureus became the most frequently isolated microorganism (30%-55%), and its polyantibiotic-resistant form Methicillin-resistant Staphylococcus aureus was found, according to various sources, from 0% to 73% among all isolated Staphylococcus aureus. In arthritis, Pasteurella multocida (6%-11%) is often isolated as a result of animal bites. Articular cartilage destruction in the experiment developed within 24-48 h after infection. In clinical studies, the development of osteomyelitis was noted when treatment was delayed by more than 10 d. X-ray data during the first two weeks were uninformative. Priority of surgical treatment of septic arthritis. Drainage and surgical treatment, and with the development of osteomyelitis, the implementation of arthrodesis. Antibacterial therapy for 2-4 wk and early start of rehabilitation measures. Timely surgical treatment in combination with antibiotic therapy and rehabilitation makes it possible to obtain a positive result in the treatment of septic arthritis of the hand.

Septic Arthritis With Superimposed Acute Gouty Arthritis in a Rheumatoid Arthritis Patient

Septic arthritis is a rare but serious complication of both rheumatoid and gouty arthritis and can lead to significant morbidity and even mortality. Here, we report a case of septic arthritis with bacteremia, monosodium urate crystals, and hyperuricemia in a 75-year-old male with long-standing rheumatoid arthritis. Arthrocentesis revealed gram-positive cocci representing group B streptococcus (Streptococcus agalactiae) infection and monosodium urate crystals. A diagnosis of septic arthritis with superimposed acute gouty arthritis was made and the patient was treated accordingly. Management included surgical irrigation and debridement, antibiotic therapy, and systemic glucocorticoids which resulted in a significant improvement in the patient’s clinical status.

Arthroplasty after septic arthritis of the native hip and knee: retrospective analysis of 49 joints

Abstract. Background: Arthroplasty after septic arthritis (SA) treatment raises diagnostic and therapeutic questions. The main objective was to evaluate infection-free survival of patients undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA) post-SA. Other objectives were to describe the population's characteristics, surgical strategies, results of preoperative examinations and cultures of intraoperative samples taken at implantation, and postoperative antibiotic therapy. Methods: This is a retrospective, observational, monocenter study, from January 2005 to May 2019, including all patients undergoing TKA or THA with prior or ongoing SA in the same joint. Infection–free survival was analyzed and reported. Results: Forty-seven patients, 29 men, 49 joints operated on (30 knees, 19 hips), were included. Median SA-to-arthroplasty interval was 32 [1–216] weeks. It was <2 years for 43 joints and <6 months for 19 joints. Six patients underwent arthroplasty while still on SA treatment. One-stage arthroplasty was done for 43 joints and two-stage arthroplasty for 6 joints. Eight (16 %) cultures of intraoperative specimens were positive. Median durations of postoperative antibiotic therapy were 10 d for sterile cultures and 82 d for those that were positive. At 2 years, infection-free survival rate was 95.9 % (±0.02). After a median follow-up of 47 [18–142] months, no SA relapse was observed, but five patients developed new periprosthetic joint infections (PJIs) with a different microorganism. Conclusion: Arthroplasty may be a post-SA option, even within a short period of time. One-stage arthroplasty can be done if synovectomy is thorough, intraoperative samples are taken and antibiotics are administered until those culture results become available. We observed no SA relapse, but new PJIs occurred.

Inflammation and nutrition based screening tests for detection of infection in cases of rapid hip destruction

Preoperative diagnosis of infection is important for appropriate surgical treatment of patients with rapid hip destruction (RHD). We investigated whether test results, including inflammatory and nutritional markers, could be used to accurately differentiate infectious and non-infectious RHD. Fifty patients with RHD who underwent total hip arthroplasty within a year of onset were observed. Infectious RHD was defined as ≥ 2 positive serological inflammatory, microbiological, or pathological evaluations. The albumin to globulin ratio (AGR), C-reactive protein (CRP)/albumin ratio (CAR), Glasgow prognostic score (GPS), modified GPS (mGPS), prognostic nutritional index (PNI), geriatric nutritional risk index (GNRI), and platelet to lymphocyte ratio (PLR) were calculated from the blood test results. In the infectious group, the white blood cell count, platelet count, CRP level, erythrocyte sedimentation rate, CAR, GPS, mGPS, and PLR were significantly higher, while the albumin level, AGR, PNI, and GNRI were significantly lower. The CRP and albumin levels showed the highest sensitivity (1.00 for both; specificity of 0.87 and 0.73, respectively) in diagnosing infectious RHD. Combining these measurements (CAR) increased the specificity to 0.92. The accuracy of other nutritional assessments was good. Thus, nutritional assessment as well as conventional assessment of the inflammatory response can improve the accuracy of preoperative diagnosis of infectious RHD.

Surgery's role in contemporary osteoarticular infection management

The treatment paradigm for osteoarticular infections (OAIs) has changed drastically over the past 80 years, from the advent of penicillin to the use of broad-spectrum antibiotics. Before these drugs, surgery was the only available treatment for OAIs; today, antibiotic therapy is considered the primary response to them. As a result, surgical treatment of OAIs is thus far more rarely indicated, sometimes even considered outdated and obsolete. However, long experience has taught us that many OAI contexts can still benefit from surgical management, constituting an essential complement to medical treatment. The present article seeks to contextualize this discussion by providing a chronological review of the surgical treatments used in cases of OAI and describing the quality of evidence supporting their rehabilitation in well-established situations.

Two-stage arthroplasty for septic arthritis of the hip and knee: A systematic review on infection control and clinical functional outcomes

INTRODUCTION

Septic arthritis of the native hip and knee joint poses particular challenges to orthopedic surgeons. Patients often suffer from several comorbidities, and it could be challenging to find a balance between infection control and adequate function. Two-stage arthroplasty has been addressed as a reliable solution, however the literature on the topic is composed of case series with small sample size. This systematic review aimed to analyze data on infection control and clinical functional outcomes of patients who underwent two-stage arthroplasty for septic arthritis of the hip and knee.

METHODS

An electronic search of studies published from January 1st, 2000, to June 1st, 2021, was conducted using eight different databases. Following the Cochrane Handbook of Systematic Reviews of Interventions and Preferred Reporting Items for Systematic Revies and Meta-analysis two authors reviewed the available literature and reference lists to identify papers eligible for inclusion.

RESULTS

A total of 21 studies were included, involving 435 procedures. The mean age was 57.3 ± 6.2 (45.8-71.8) years. The mean follow-up was 53.7 ± 18.6 (12-86.7) months. The mean infection eradication was 93.3 ± 6.4%. Mean Harris Hip Score improved from 32.1 ± 10.6 (11.5-42.9) to 87.5 ± 5.7 (80.6-97.8). Mean Knee Society Score improved from 42.9 ± 7.6 (35.9-58.0) to 86.1 ± 5.4 (80.1-96.0).

CONCLUSIONS

Two-stage arthroplasty for hip and knee septic arthritis provided high infection control rate and excellent function. Further high-quality studies should be oriented on providing a validated algorithm for diagnosis and treatment of this condition.

LEVEL OF EVIDENCE

Level IV, systematic review of Level III and IV studies.

A Case of Septic Arthritis Caused by Staphylococcus schleiferi

Septic arthritis leads to significant hospital burden in the United States adult patient population. Bacteria are the leading cause of septic arthritis with Staphylococcus aureus being the most common. Of the staphylococcal species, Staphylococcus ​​​​​​​schleiferi, primarily found in carnivores, rarely causes septic arthritis. We here report the presentation, diagnosis, treatment, and discharge of a 39-year-old male with S. schleiferi septic arthritis. Due to biochemical similarities, S. schleiferi are commonly misidentified as S. aureus, and correct identification is increasingly relevant for the selection of appropriate therapy due to the rise in cases of multidrug-resistant microorganisms.

Septic hip abscess due to Fusobacterium nucleatum and Actinomyces turicensis in an immunocompetent SARS-CoV-2 positive patient

A 42-year-old man was referred to the Department of Orthopedic Surgery with pain over his right greater trochanter and signs of systemic infection. CT showed an enhanced mass in his gluteus maximus as well as gas in the biceps femoris over the underlying hip joint. Tissue biopsy yielded Fusobacterium nucleatum and Actinomyces turicensis. The patient was successfully treated for 6 weeks with amoxicillin/clavulanic acid 875mg/125mg and metronidazole 500mg.

Novel therapeutic interventions towards improved management of septic arthritis

Septic arthritis (SA) represents a medical emergency that needs immediate diagnosis and urgent treatment. Despite aggressive treatment and rapid diagnosis of the causative agent, the mortality and lifelong disability, associated with septic arthritis remain high as close to 11%. Moreover, with the rise in drug resistance, the rates of failure of conventional antibiotic therapy have also increased. Among the etiological agents frequently isolated from cases of septic arthritis, Staphylococcus aureus emerges as a dominating pathogen, and to worsen, the rise in methicillin-resistant S. aureus (MRSA) isolates in bone and joint infections is worrisome. MRSA associated cases of septic arthritis exhibit higher mortality, longer hospital stay, and higher treatment failure with poorer clinical outcomes as compared to cases caused by the sensitive strain i.e methicillin-sensitive S. aureus (MSSA).

In addition to this, equal or even greater damage is imposed by the exacerbated immune response mounted by the patient’s body in a futile attempt to eradicate the bacteria. The antibiotic therapy may not be sufficient enough to control the progression of damage to the joint involved thus, adding to higher mortality and disability rates despite the prompt and timely start of treatment. This situation implies that efforts and focus towards studying/understanding new strategies for improved management of sepsis arthritis is prudent and worth exploring.

The review article aims to give a complete insight into the new therapeutic approaches studied by workers lately in this field. To the best of our knowledge studies highlighting the novel therapeutic strategies against septic arthritis are limited in the literature, although articles on pathogenic mechanism and choice of antibiotics for therapy, current treatment algorithms followed have been discussed by workers in the past. The present study presents and discusses the new alternative approaches, their mechanism of action, proof of concept, and work done so far towards their clinical success. This will surely help to enlighten the researchers with comprehensive knowledge of the new interventions that can be used as an adjunct therapy along with conventional treatment protocol for improved success rates.

Economic burden of surgical management of surgical site infections following hip and knee replacements in Calgary, Alberta, Canada

OBJECTIVE

To evaluate the cost of 1-stage and 2-stage revisions, debridement, antibiotic and implant retention (DAIR) and DAIR with liner exchange for complex surgical site infections (SSIs) following hip and knee replacements.

DESIGN

Retrospective population-based economic analysis of patients undergoing intervention for SSIs between April 1, 2012 and March 31, 2019.

SETTING

The study was conducted in the Calgary zone of Alberta Health Services (AHS) in Canada.

PARTICIPANTS

Individuals >18 years with complex SSI following hip or knee replacement.

METHODS

Patients with complex SSIs were identified using the AHS infection prevention and control database. A combination of microcosting and gross costing methods were used to estimate 12- and 24-month costs following the initial hospital admission for arthroplasty. Subgroup, inverse Gaussian and γ regression analyses were used to evaluate the impact of age and comorbidities on cost.

RESULTS

In total, 142 patients with complex SSIs were identified, with a mean age of 66.8 years. Total direct medical costs in United States dollars of 2-stage revisions were ($100,992 (95% CI, 34,587-167,396) at 12 months. The 1-stage revision ($41,176; 95% CI, 23,361-58,991), DAIR with liner exchange ($41,267; 95% CI, 29,923-52,612) and DAIR ($46,605; 95% CI, 15,277-76,844) were associated with fewer costs at 12 months. Age >65 years and chronic complications of diabetes and hypertension were associated with increased costs in subgroup and regression analysis.

CONCLUSIONS

Medical costs are highest at 12 months and for 2-stage revisions in hip and knee complex SSI cases. Further work should explore surgical outcomes correlated with costs to enhance patient care.

Dual therapeutic targeting of intra-articular inflammation and intracellular bacteria enhances chondroprotection in septic arthritis

Bacterial infections involving joints and vital organs represent a challenging clinical problem because of the two concurrent therapeutic goals of bacterial eradication and tissue preservation. In the case of septic arthritis, permanent destruction of articular cartilage by intense host inflammation is commonly seen even after successful treatment of bacterial infection. Here, we provide scientific evidence of a novel treatment modality that can protect articular cartilage and enhanced eradication of causative bacteria in septic arthritis. Locally delivered cell-penetrating antibiotics such as rifampicin effectively eradicate intracellular reservoirs of methicillin-resistant Staphylococcus aureus within joint cells. Furthermore, mitigation of intra-articular inflammation by targeting the NLRP3 (nucleotide-binding oligomerization domain-, leucine-rich repeat- and pyrin domain-containing 3) inflammasome protects articular cartilage from damage in a murine model of knee septic arthritis. Together, concurrent mitigation of intra-articular inflammation and local adjuvant targeting of intracellular bacteria represents a promising new therapeutic strategy for septic arthritis.

Streptococcus gordonii septic arthritis of the glenohumeral joint following deltoid intramuscular vaccination

A 68-year-old woman presented for left shoulder pain, decreased range of motion (ROM) and fever 7 days following COVID-19 vaccination. Investigations showed a tender left deltoid mass, decreased shoulder ROM and elevated inflammatory markers. MRI demonstrated a large glenohumeral effusion with synovitis, and arthrocentesis confirmed septic arthritis (SA). She required subtotal bursectomy. Intraoperative joint cultures grew Streptococcus gordonii She completed 6 weeks of antibiotics and is undergoing physical therapy for post-infectious adhesive capsulitis. SA is most commonly due to Staphylococcus aureus and β-haemolytic streptococci, and rarely due to viridans group streptococci including S. gordonii To avoid inadvertent injection into the glenohumeral joint, vaccination should be performed posteriorly and inferiorly into the deltoid musculature. Progressive pain, fever or decreased passive ROM following vaccination should raise concern for SA. Given its rarity, however, concern for secondary SA should not affect the general population's consideration for vaccination.

Evaluation of Intra-Articular Amikacin Administration in an Equine Non-inflammatory Joint Model to Identify Effective Bactericidal Concentrations While Minimizing Cytotoxicity

Septic arthritis causes significant morbidity and mortality in veterinary and human clinical practice and is increasingly complicated by multidrug-resistant infections. Intra-articular (IA) antibiotic administration achieves high local drug concentrations but is considered off-label usage, and appropriate doses have not been defined. Using an equine joint model, we investigated the effects of amikacin injected at three different doses (500, 125, and 31.25 mg) on the immune and cartilage responses in tibiotarsal joints. Synovial fluid (SF) was sampled at multiple time points over 24 h, the cell counts determined, and amikacin concentrations measured by liquid chromatography-mass spectrometry. Cytokine concentrations and collagen degradation products in SF were measured by ELISA and multiplex immunoassays. The mean amikacin concentrations in SF were greater than or equal to the minimum inhibitory concentration (MIC) (0.004 mg/ml) for most common equine joint pathogens at all time points tested to 24 h for all three amikacin doses evaluated. The inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) increased significantly in SF in the highest amikacin dose group, despite the fact that increases in SF cell counts were not observed. Similarly, the biomarkers of cartilage type II collagen cleavage (C2C and C12C) were increased in SF following amikacin injection. Mechanistically, we further demonstrated using in vitro studies that chondrocytes and synoviocytes killed by exposure to amikacin underwent apoptotic cell death and were phagocytosed by macrophages in a non-inflammatory process resembling efferocytosis. Neutrophils and T cells were susceptible to amikacin cytotoxicity at clinically relevant doses, which may result in blunting of cellular inflammatory responses in SF and account for the lack of increase in total nucleated cell counts following amikacin injection. In summary, decisions on whether to inject cytotoxic antibiotics such as aminoglycosides intra-articularly and what doses to use should take into account the potential harm that antibiotics may cause and consider lower doses than those previously reported in equine practice.

Clinical outcomes and survivorship of two-stage total hip or knee arthroplasty in septic arthritis: a retrospective analysis with a minimum five-year follow-up

Purpose

Septic arthritis of the native joint is challenging for orthopedic surgeons because it may lead to wide bone defects and severe impairment of joint function. This study aimed to analyze clinical functional outcomes, the rate of infection eradication, and survival of implants of patients who underwent two-stage arthroplasty for septic arthritis of the hip and knee.

Methods

A retrospective single-centre analysis was conducted of patients treated for septic arthritis of the hip and knee joints through a two-stage surgery between 2012 and 2015. Clinical and radiological records were gathered from the prospectively collected Institutional Arthroplasty Registry. Patients’ pre-operative Harris hip scores and Knee Society scores were compared with those obtained at the latest follow-up. Kaplan–Meier curves were generated to assess survival of implants.

Results

Forty-seven patients were included. The mean follow-up was 85.2 ± 15.4 months. The Harris hip score improved from 39.4 ± 9.9 to 84.5 ± 10.8 points (p < 0.001). The Knee Society score improved from 40.7 ± 8.4 to 86.0 ± 7.8 points (p < 0.001). Knee Society score-function increased from 25.7 ± 14.2 to 85.4 ± 23.4 points (p < 0.001). The infection eradication rates were 92.0% and 90.9% in patients who underwent hip and knee operation, respectively (p = 0.891). Overall survivorship of implants after the second stage was 93.6%.

Conclusions

Two-stage arthroplasty provides good to excellent clinical outcomes in cases of active septic arthritis of the hip and the knee, high rates of infection control, and implant survival.

Challenges in reducing the risk of infection when accessing vascular catheters

Injection safety is essential to reduce the risk of healthcare-associated infections (HAIs) when accessing vascular catheters. This general review evaluates the contamination of vascular catheter access ports and associated HAIs in acute care settings, focusing on open lumen stopcocks (OLSs) and disinfectable needleless closed connectors (DNCCs). PubMed was searched from January 2000 to February 2021. OLS intraluminal surfaces are frequently contaminated during patient care, increasing the risk of HAIs, and neither an isopropyl alcohol (IPA) pad nor a port-scrub device can reduce contamination effectively. In contrast, DNCCs can be disinfected, with most studies indicating less intraluminal contamination than OLSs and some studies showing decreased HAIs. While the optimal DNCC design to reduce HAIs needs to be determined, DNCCs alone or stopcocks with a DNCC bonded to the injection port should replace routine use of OLSs, with OLSs restricted to use in sterile fields. Compliance with disinfection is essential immediately before use of a DNCC as use of a non-disinfected DNCC can have equivalent or greater risk of HAIs compared with use of an OLS. The recommendations for access port disinfection in selected national and international guidelines vary. When comparing in-vitro studies, clinical studies and published guidelines, consensus is lacking; therefore, additional studies are needed, including large randomized controlled trials. IPA caps disinfect DNCCs passively, eliminate scrubbing and provide a contamination barrier; however, their use in neonates has been questioned. Further study is needed to determine whether IPA caps are more efficacious than scrubbing with disinfectant to decrease HAIs related to use of central venous, peripheral venous and arterial catheters.

Clinical Outcomes and Global Health After Joint Debridement in Adult-Onset Septic Arthritis: A Prospective Observational Study

PURPOSE

Despite several reports on risk factors for septic arthritis (SA) in adults, the outcomes on quality of life and joint function are sparsely reported. This study aimed to investigate the quality of life and joint function in adult patients treated for SA.

METHODS

This prospective observational study enrolled clinically diagnosed adult SA patients and estimated Euroqol 5-dimension 5 levels (EQ-5D-5L) questionnaire, Euroqol Visual Analog Scale (EQ-VAS) and a validated tool for joint function at 1, 3, 6 and 12 months after debridement.

RESULTS

Twenty seven patients (20 males/7 females) with 21 knees, four shoulders, and two elbows were evaluated. The mean age of the cases was 51(± 13.00) years. Three cases sustained mortality. EQ-5D-5L (P < 0.01) and EQ-VAS (P < 0.01) scores improved significantly between all time frames. Mean Knee society (P < 0.01), Shoulder QuickDASH, and Mayo elbow scores improved at all time frames. There was no difference in primary outcomes between early (< 14 days) and late (14 days or more) presentation. There was no difference in primary outcome measures between confirmed and suspected SA. Fifteen patients could ambulate without support, while 6 needed some support for walking at 1 year.

CONCLUSION

Improved outcomes can be expected in quality of life and joint function in adults' septic arthritis at the end of 1 year after surgical treatment; however, the effects of delay in presentation need to be investigated further. Isolation of the microorganism from an infected joint has no bearing on the outcome measures.

Recommended Musculoskeletal and Sports Medicine Curriculum for Internal Medicine Residency Training

ABSTRACT

Patients present to primary care physicians with musculoskeletal complaints more often than they do for upper respiratory infections, hypertension, or diabetes. Despite this, instruction in musculoskeletal medicine for internal medicine residents represents less than 1% of their total didactic and clinical education time. We recognize the immense breadth of knowledge and skill required to train residents in the practice of internal medicine. This curriculum guideline defines a recommended training strategy, and supplies relevant resources, to improve musculoskeletal education among internal medicine residents to optimize patient care. This curriculum guideline was created by internists who are sports medicine specialists. Sports medicine physicians promote overall health and well-being while providing expertise in acute and chronic musculoskeletal conditions, as well as how disease affects exercise and using exercise as medicine for people with chronic disease.

Antibiotic Tolerance of Staphylococcus aureus Biofilm in Periprosthetic Joint Infections and Antibiofilm Strategies

The need for bone and joint prostheses is currently growing due to population aging, leading to an increase in prosthetic joint infection cases. Biofilms represent an adaptive and quite common bacterial response to several stress factors which confer an important protection to bacteria. Biofilm formation starts with bacterial adhesion on a surface, such as an orthopedic prosthesis, further reinforced by matrix synthesis. The biofilm formation and structure depend on the immediate environment of the bacteria. In the case of infection, the periprosthetic joint environment represents a particular interface between bacteria, host cells, and the implant, favoring biofilm initiation and maturation. Treating such an infection represents a huge challenge because of the biofilm-specific high tolerance to antibiotics and its ability to evade the immune system. It is crucial to understand these mechanisms in order to find new and adapted strategies to prevent and eradicate implant-associated infections. Therefore, adapted models mimicking the infectious site are of utmost importance to recreate a relevant environment in order to test potential antibiofilm molecules. In periprosthetic joint infections, Staphylococcus aureus is mainly involved because of its high adaptation to the human physiology. The current review deals with the mechanisms involved in the antibiotic resistance and tolerance of Staphylococcus aureus in the particular periprosthetic joint infection context, and exposes different strategies to manage these infections.

Mid- to Long-Term Outcomes After Deep Infections After Arthroscopic Rotator Cuff Repair

Purpose

To review clinical and subjective outcomes in patients with deep infections after arthroscopic rotator cuff repair.

Methods

All patients in whom deep infections developed after arthroscopic rotator cuff repair at a single center between 2002 and 2016 were retrospectively reviewed. Demographic data, clinical and microbiological findings, and treatment were analyzed. Clinical and subjective outcomes included the Constant score, visual analog scale score for pain, American Shoulder and Elbow Surgeons score, and Simple Shoulder Test score.

Results

Thirty patients could be identified and included in the study. The most commonly isolated pathogens were Staphylococcus epidermidis (36.7%) and Cutibacterium acnes (30.0%). In 26 of 30 patients (86.7%), the infection was treated initially with an open surgical approach, whereas 4 patients (13.3%) underwent arthroscopic revision. A transosseous rotator cuff repair could be performed in 20.0% of patients. A single reoperation was sufficient in 80% of patients, whereas 13.3% required 2 revisions and 6.7% required 3. At the final follow-up of 8.3 years (range, 4-14 years), 26 patients (1 woman and 25 men) were available for outcome evaluation. Significant improvement from the initial surgical procedure to final follow-up was detected in the Constant score (25.7 vs 65.7, P < .001), visual analog scale score for pain (7.0 vs 1.7, P < .001), American Shoulder and Elbow Surgeons score (38.0 vs 76.7, P < .001), and Simple Shoulder Test score (4.0 vs 8.3, P < .001).

Conclusions

Patients with deep infections after arthroscopic rotator cuff repair showed moderate mid- to long-term outcomes.

Level of Evidence

Level IV, therapeutic case series.

Platelet-rich plasma lysate displays antibiofilm properties and restores antimicrobial activity against synovial fluid biofilms in vitro

Infectious arthritis is difficult to treat in both human and veterinary clinical practice. Recent literature reports Staphylococcus aureus as well as other gram-positive and gram-negative isolates forming free-floating biofilms in both human and equine synovial fluid that are tolerant to traditional antimicrobial therapy. Using an in vitro equine model, we investigated the ability of platelet-rich plasma (PRP) formulations to combat synovial fluid biofilm aggregates. Synovial fluid was infected, and biofilm aggregates allowed to form over a 2-hour period. PRP was collected and processed into different formulations by platelet concentration, leukocyte presence, and activation or lysis. Infected synovial fluid was treated with different PRP formulations with or without aminoglycoside cotreatment. Bacterial load (colony-forming unit/mL) was determined by serial dilutions and plate counting at 8 hours posttreatment. All PRP formulations displayed antimicrobial properties; however, formulations containing higher concentrations of platelets without leukocytes had increased antimicrobial activity. Lysis of PRP and pooling of the PRP lysate (PRP-L) from multiple horses as compared to individual horses further increased antimicrobial activity. This activity was lost with the removal of the plasma component or inhibition of the proteolytic activity within the plasma. Fractionation of pooled PRP-L identified the bioactive components to be cationic and low-molecular weight (<10 kDa). Overall, PRP-L exhibited synergism with amikacin against aminoglycoside tolerant biofilm aggregates with greater activity against gram-positive bacteria. In conclusion, the use of PRP-L has the potential to augment current antimicrobial treatment regimens which could lead to a decrease in morbidity and mortality associated with infectious arthritis.

Synovial Fluid Mediated Aggregation of Clinical Strains of Four Enterobacterial Species

Septic arthritis and prosthetic joint infection (PJI) are conditions commonly associated with Gram-positive cocci, however, a drastic increase in cases derived from enterobacterial species has been observed. Recently it has been reported by multiple groups that staphylococci rapidly form free-floating aggregates in the presence of synovial fluid. These aggregates are comparatively more resistant to antimicrobial challenge than their planktonic counterparts, and thus may play a role in the pathogenesis of joint infection. While staphylococcal aggregates have been the primary focus of interest in the field, it is unclear just how widespread synovial fluid mediated aggregation (SFMA) is in Gram negative enterobacteria (GNE). Through this work we have evaluated SFMA in clinical GNE isolated from PJIs. Two PJI clinical strains each of Enterobacter cloacae, Escherichia coli, Klebsiella pneumonia and Proteus mirabilis strains representing a range of antibiotic susceptibilities were exposed to 10% bovine synovial fluid supernatant (BSF) using a relatively simple, quick semi-quantitative method using an imaging plate reader. BSF stimulated aggregation within 0.5 h both strains of E. cloacae and P. mirabilis and one strain of E.coli. In one strain of P. mirabilis and E.coli, the size of the aggregates significantly increased from 0.5 to 2 h exposure. In contrast, neither K. pneumoniae strain aggregated in BSF. These preliminary findings show that aggregation can occur quickly in GNE, but the extent appears strain and species specific. Further work is required to assess the impact of SFMA on antibiotic tolerance, host innate immunity and the establishment of biofilms.

Native Joint Septic Arthritis: Comparison of Outcomes with Medical and Surgical Management

OBJECTIVE

To determine whether there are differences in the outcomes of native joint septic arthritis (SA) in adults, based on medical versus surgical management.

METHODS

A 10-year retrospective single-center study was conducted of patients admitted to a tertiary care hospital between January 1, 2006 and December 31, 2015 with a diagnosis of SA to compare outcomes based on the management approach taken: medical (bedside closed-needle joint aspiration) versus surgical (arthrotomy/arthroscopy). Evaluated outcomes included joint recovery, time to recovery, length of stay, disposition to home versus rehabilitation unit, recurrence of SA in the same joint, and mortality.

RESULTS

Of 118 confirmed cases of SA, 48 were in prosthetic joints and 70 were in native joints, and 61 met our inclusion criteria. Forty-one (67%) patients received surgery, and 20 (33%) received closed-needle aspiration. There was no statistically significant difference in long-term outcomes between the two groups at 12 months. Patients managed medically were more likely to experience full recovery at 3 months and were less likely to need short-term rehabilitation.

CONCLUSIONS

Medical management with closed-needle aspiration may be an adequate approach to the treatment of native joint infections.

Outcomes and predictors of treatment failure following two-stage total joint arthroplasty with articulating spacers for evolutive septic arthritis

Background

The treatment strategy for evolutive septic arthritis (SA) with coexistent degenerative joint disease is not well established. The purposes of this study were to 1) investigate treatment outcome and potential risk factors of treatment failure in patients with evolutive SA following two-stage procedure, including insertion of an antibiotic-loaded spacer at the first stage and subsequent implantation of a new prosthesis; and 2) determine the performance of serum erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and Interleukin-6 (IL-6) in predicting persisting infection at second-stage procedure.

Methods

We retrospectively reviewed 74 patients with evolutive SA of hips and knees who underwent a two-stage TJA between 2008 and 2015. The treatment success was defined according to the modified Delphi criteria and Kaplan-Meier survivorship curves were constructed to determine treatment success. A Cox regression model was performed to identify risk factors for treatment failure. Receiver operating characteristic (ROC) curves were generated to determine the prognostic value of ESR, CRP, and IL-6 in predicting persistent infection before second-stage prostheses implantation.

Results

Overall, the treatment success rate was 93% for hips and 100% for knees after the first-stage surgery. The treatment success rate was 89% for hips and 84% for knees after second-stage prosthesis implantation with a mean follow-up of 4.7 (range, 2.2 to 10.8) years. Older age (Hazard ratio [HR] [per 10-year increase], 1.20; 95% confidential interval [CI], 1.11 to 1.62), higher preoperative CRP level (HR [per 1-mg/dL increase], 1.15; 95% CI, 1.04 to 1.28) and resistant organism (HR, 13.96; 95% CI, 3.29 to 19.20) were associated with an increased risk of treatment failure. All serologic tests presented limited values in predicting persisting infection, with the area under ROC curve of ESR, CRP, IL-6 and combination of the three markers was 57.8, 61.6, 60.3, and 62.1%, respectively.

Conclusions

Two-stage TJA is an adequate management of infection control in patients with evolutive SA. The three potential risk factors (old age, high preoperative CRP, and resistant organism profile) may predict treatment failure following a two-stage procedure for evolutive SA. Additionally, serum ESR, CRP, and IL-6 had no benefit in predicting persisting infection before second-stage prostheses implantation. These findings may be useful when treating patients with evolutive SA.