Factors predictive of Cutibacterium periprosthetic shoulder infections: a retrospective study of 342 prosthetic revisions

Risk Factors for Stiffness Requiring Intervention After Ream-and-Run Arthroplasty

Ream-and-run arthroplasty can improve pain and function in patients with glenohumeral arthritis while avoiding the complications and activity restrictions associated with a prosthetic glenoid component. However, stiffness is a known complication after ream-and-run arthroplasty and can lead to repeat procedures such as a manipulation under anesthesia (MUA) or open surgical revision. The objective of this study was to determine risk factors associated with repeat procedures indicated for postoperative stiffness after ream-and-run arthroplasty.

Methods

We conducted a retrospective review of our shoulder arthroplasty database to identify patients who underwent ream-and-run arthroplasty and determined which patients underwent subsequent repeat procedures (MUA and/or open revision) indicated for postoperative stiffness. The minimum follow-up was 2 years. We collected baseline demographic information and preoperative and 2-year patient-reported outcome scores and analyzed preoperative radiographs. Univariate and multivariate analyses determined the factors significantly associated with repeat procedures to treat postoperative stiffness.

Results

There were 340 patients who underwent ream-and-run arthroplasty. The mean Simple Shoulder Test (SST) scores for all patients improved from 5.0 ± 2.4 preoperatively to 10.2 ± 2.6 postoperatively (p < 0.001). Twenty-six patients (7.6%) underwent open revision for stiffness. An additional 35 patients (10.3%) underwent MUA. Univariate analysis found younger age (p = 0.001), female sex (p = 0.034), lower American Society of Anesthesiologists (ASA) class (p = 0.045), posterior decentering on preoperative radiographs (p = 0.010), and less passive forward elevation at the time of discharge after ream-and-run arthroplasty (p < 0.001) to be significant risk factors for repeat procedures. Multivariate analysis found younger age (p = 0.040), ASA class 1 compared with class 3 (p = 0.020), and less passive forward elevation at discharge (p < 0.001) to be independent risk factors for repeat procedures. Of the patients who underwent open revision for stiffness, 69.2% had multiple positive cultures for Cutibacterium.

Conclusions

Younger age, ASA class 1 compared with class 3, and less passive forward elevation in the immediate postoperative period were independent risk factors for repeat procedures to treat postoperative stiffness after ream-and-run arthroplasty.

Level of Evidence

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

A high prevalence of Cutibacterium acnes infections in scoliosis revision surgery, a diagnostic and therapeutic dilemma

PURPOSE

To investigate if serum inflammatory markers or nuclear imaging can accurately diagnose a chronic spinal instrumentation infection (SII) prior to surgery.

METHODS

All patients who underwent revision of spinal instrumentation after a scoliosis correction between 2017 and 2019, were retrospectively evaluated. The diagnostic accuracy of serum C-reactive protein (CRP) and Erythrocyte Sedimentation Rate (ESR), ¹⁸F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) and Technetium-99m-methylene diphosphonate (99mTc-MDP) 3-phase bone scintigraphy (TPBS) to diagnose infection were studied. Patients with an acute infection or inadequate culture sampling were excluded. SII was diagnosed if ≥ 2 of the same microorganism(s) were isolated from intra-operative tissue cultures.

RESULTS

30 patients were included. The indication for revision surgery was pseudoarthrosis in the majority of patients (n = 15). 22 patients (73%) were diagnosed with SII. In all infected cases, Cutibacterium acnes was isolated, including 5 cases with a polymicrobial infection. The majority of patients had low inflammatory parameters preoperatively. For CRP > 10.0 mg/L, the sensitivity was 9.1% and specificity 100%; for ESR > 30 mm/h, the sensitivity was 9.1% and specificity 100%. The diagnostic accuracy for nuclear imaging was 64% for the FDG-PET/CT and 67% for the TPBS to diagnose infection.

CONCLUSIONS

The prevalence of SII in patients undergoing revision spinal surgery is high, with Cutibacterium acnes as the main pathogen. No diagnostic tests could be identified that could accurately diagnose or exclude SII prior to surgery. Future studies should aim to find more sensitive diagnostic modalities to detect low-grade inflammation.

Techniques for Decreasing Bacterial Load for Open Shoulder Surgery

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Benzoyl peroxide (BPO) 5% has been shown to reduce Cutibacterium acnes load on the skin. BPO 5% with miconazole nitrate (MN) 2% may be beneficial, whereas BPO 5% with clindamycin cream 1% to 1.2% does not seem to have additive effects when compared with BPO 5% alone. Chlorhexidine gluconate solutions reduce the total bacterial load on the skin, but do not seem to have a significant effect on C. acnes.

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ChloraPrep seems to be the best surgical skin preparation to decrease overall positive skin cultures. Preincisional hydrogen peroxide 3% application has been shown to be a cost-effective practice to inhibit growth of C. acnes. Vancomycin powder before deltopectoral interval closure has antimicrobial effects against C. acnes and is a cost-effective practice. Finally, Bactisure surgical lavage is protective against the formation of biofilms.

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IV cefazolin has been shown to be more effective for shoulder arthroplasty infection prophylaxis than antibiotic alternatives such as vancomycin. Thus, patients with a questionable history of penicillin allergy should undergo additional testing.

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For shoulder surgery infection prophylaxis, we recommend the use of BPO 5% cream for 5 days preoperatively with chlorhexidine wipes the night before and the morning of surgery. IV cefazolin should be administered perioperatively, and patients with a questionable history of penicillin allergy should be tested. Surgeons should consider preincisional application of hydrogen peroxide 3% for 5 minutes, followed by standard ChloraPrep preparation. Normal saline should be used for preclosure lavage. Finally, application of vancomycin powder deep to the deltopectoral interval closure should be considered.

Oral and IV Antibiotic Administration After Single-Stage Revision Shoulder Arthroplasty: Study of Survivorship and Patient-Reported Outcomes in Patients without Clear Preoperative or Intraoperative Infection

BACKGROUND

Following revision shoulder arthroplasty, postoperative antibiotics are selected before the results of intraoperative cultures become available. We determined infection-free survival, revision-free survival, complications, and patient-reported outcomes for patients selected to receive oral or intravenous (IV) antibiotics after revision arthroplasty.

METHODS

This study included 92 patients who had revision shoulder arthroplasty. IV antibiotics were administered if the surgeon had a high index of suspicion for infection, and oral antibiotics were given if there was a low suspicion. Antibiotic therapy was modified based on intraoperative culture results. Patient-reported outcomes and adverse events were documented at a mean of 4.1 years.

RESULTS

In selecting antibiotic therapy, surgeons correctly predicted the presence or absence of multiple positive cultures of specimens from the revision surgery in 72% of the 92 cases. Subsequent re-revision surgery was required in 17 (18%) of the patients; 8 of these 17 patients had ≥2 positive cultures at re-revision. Patients who initially received IV antibiotics and those who initially received oral antibiotics had similar revision-free (p = 0.202) and infection-free (p = 0.155) survivorship. Patients requiring a change from oral to IV antibiotics based on positive cultures had similar survivorship compared with those initially treated with IV antibiotics. The IV and oral antibiotic groups had similar postoperative Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES), and satisfaction scores. Patients receiving IV antibiotics had a higher rate of antibiotic-related adverse events.

CONCLUSIONS

Post-revision antibiotic therapy was associated with an infection-free survival rate of 91% at a mean of >4 years of follow-up. Infection-free survival, revision-free survival, and patient-reported outcomes were similar in high-risk patients placed on IV antibiotics and low-risk patients placed on oral antibiotics. Further study is needed to define the indications for IV or oral antibiotics after revision arthroplasty.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Factors associated with failure of surgical revision and IV antibiotics to resolve Cutibacterium periprosthetic infection of the shoulder

PURPOSE

Cutibacterium is the most common organism causing shoulder periprosthetic infection (PJI). While most shoulder PJIs are well treated by prosthesis exchange and antibiotics, in some cases this treatment fails to resolve the infection. The factors associated with these failures have not been previously identified. The aim of this study was to identify the characteristics of patients with failure of treatment for PJI.

METHODS

Thirty-five patients suspected of having Cutibacterium PJI had revision arthroplasty with single-stage implant exchange followed by intravenous antibiotics. The characteristics of those with ≥ two positive cultures at revision surgery were compared to those who did not. The characteristics of those patients having a re-revision with ≥ two positive deep cultures (documented treatment failures) were compared to those who did not.

RESULTS

The 17 patients that had ≥ two positive cultures at their index revision were more likely to be male, to have had ream and run procedures, and to have higher loads of Cutibacterium on pre-operative cultures of their unprepared skin. The five patients that had documented treatment failure had higher loads of Cutibacterium on their skin and in deep cultures obtained at their index revision.

CONCLUSION

Patients harboring high loads of Cutibacterium on their unprepared skin prior to revision and high loads of Cutibacterium on deep cultures at the time of their index revision are at increased risk for failure of implant exchange and antibiotics to resolve a Cutibacterium PJI.

Association Between Serum Testosterone Levels and Cutibacterium Skin Load in Patients Undergoing Elective Shoulder Arthroplasty: A Cohort Study

Cutibacterium periprosthetic joint infections are important complications of shoulder arthroplasty. Although it is known that these infections are more common among men and that they are more common in patients with high levels of Cutibacterium on the skin, the possible relationship between serum testosterone levels and skin Cutibacterium levels has not been investigated.

Shoulder Hemiarthroplasty with Nonprosthetic Glenoid Arthroplasty: The Ream-and-Run Procedure

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Glenoid component wear and loosening are the principal failure modes of anatomic total shoulder arthroplasty (aTSA).

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The ream-and-run (RnR) procedure is an alternative glenohumeral arthroplasty for patients who wish to avoid the risks and limitations of a prosthetic glenoid component.

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During the RnR procedure, the arthritic glenoid is conservatively reamed to a single concavity, while the prosthetic humeral component and soft tissues are balanced to provide both mobility and stability of the joint.

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The success of the RnR procedure depends on careful patient selection, preoperative education and engagement, optimal surgical technique, targeted rehabilitation, and close postoperative communication between the surgeon and the patient.

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While the RnR procedure allows high levels of shoulder function in most patients, the recovery can be longer and more arduous than with aTSA.

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Patients who have undergone an RnR procedure occasionally require a second closed or open procedure to address refractory shoulder stiffness, infection, or persistent glenoid-sided pain. These second procedures are more common after the RnR than with aTSA.

Cutibacterium acnes in shoulder surgery: a scoping review of strategies for prevention, diagnosis, and treatment

BACKGROUND

Cutibacterium acnes is a commensal, gram-positive, facultatively anaerobic bacillus that resides in the dermis. Historically thought to be a contaminant when identified on cultured specimens, recent advances in diagnostic technology have now implicated it as the most common organism responsible for postoperative shoulder infections. Despite a recognition of the role of this organism and a significant research interest in recent years, there is clear lack of consensus guideline on strategies to prevent, diagnose, and treat postoperative shoulder infection.

METHOD

The electronic databases PubMed, MEDLINE, CINAHL, Scopus, and Web of Science were searched in March 2020. All experimental and nonexperimental studies that investigate C acnes in shoulder surgery were included. Inclusion was limited to articles published after 2000 and written in English; reviews, gray literature, or abstracts were excluded. A total of 70 studies were included in this review. This scoping review was performed in accordance with the Extended Preferred Reporting Items of Systematic Reviews and Meta-Analyses Statement for Scoping Reviews (PRISMA-ScR).

RESULTS

Standard surgical prophylactic regimens such as intravenous antibiotics and topical chlorhexidine are ineffective at removing C acnes from the deep layer of the dermis, and there is a shift toward using topical benzoyl peroxide with significantly improved efficacy. An improved understanding of the bacteria has demonstrated that a prolonged culture time of up to 14 days is needed, especially in cases of established infection. Advances in diagnostics such as sonication and molecular-based testing are promising. Although usually thought to be susceptible to a broad range of antibiotics, resistance is emerging to clindamycin. An improved understanding of its ability to form a biofilm highlights the difficulty in treating an established infection.

CONCLUSION

The role of C acnes causing postoperative infection following shoulder surgery is being increasingly recognized. Strategies for prevention, diagnosis, and treatment have been outlined from both an antimicrobial and surgical perspective. A number of these strategies are emerging and require further research to demonstrate efficacy before implementation into clinical guidelines.

Unexpected positive cultures after revision shoulder arthroplasty: does it affect outcome?

BACKGROUND

Several studies have confirmed a high rate of unexpected positive cultures (UPCs) after presumably aseptic revisions of shoulder arthroplasties; however, the impact on the outcome is still unclear. The purpose of this prospective study is to compare the patient-reported outcomes of standard revisions with and without the emergence of UPCs.

METHODS

During a 3-year period, we included all patients who were revised for reasons other than suspicion of infection from 2 orthopedic centers. Five biopsies were obtained from every revision, and only cultures with the same bacteria in at least 3 biopsy specimens were classified as UPCs. All patients were assessed using the Oxford Shoulder Score (OSS) and range of motion preoperatively and after at least a 2-year follow-up.

RESULTS

In this study, 124 patients were included, with a median follow-up of 29 months (range 29-32), and UPCs emerged after 27 revisions (22%), with Cutibacterium acnes accounting for 67% (18/27). At baseline, the OSS was 22 in both the culture-negative and UPC groups (P = .46). Then, at follow-up, the OSS was 37 in the culture-negative group and 35 in the UPC group (P = .91). The forward elevation increased significantly by 44° and 41°, respectively, in the 2 groups, but no statistically significant difference between the culture-negative group and the UPC group was found (P = .66). In contrast, the external rotation was unchanged after the revision, and again, no difference in the change between the culture-negative and UPC groups (P = .54) was observed. Subgroup analyses stratified by different implant designs revealed equal patterns with no statistical differences in outcome.

CONCLUSION

We did not find a difference in outcome after a presumed aseptic revision regardless of the emergence of UPCs. Similarly, we could not demonstrate that patients with UPCs presented with poorer function at baseline compared with culture-negative patients. The clinical relevance of UPCs thus requires further evaluation, especially in the case of C acnes as a potential pathogenic versus a merely colonizing microbe.

Prosthetic Shoulder Joint Infection by Cutibacterium acnes: Does Rifampin Improve Prognosis? A Retrospective, Multicenter, Observational Study

This retrospective, multicenter observational study aimed to describe the outcomes of surgical and medical treatment of C. acnes-related prosthetic joint infection (PJI) and the potential benefit of rifampin-based therapies. Patients with C. acnes-related PJI who were diagnosed and treated between January 2003 and December 2016 were included. We analyzed 44 patients with C. acnes-related PJI (median age, 67.5 years (IQR, 57.3-75.8)); 75% were men. The majority (61.4%) had late chronic infection according to the Tsukayama classification. All patients received surgical treatment, and most antibiotic regimens (43.2%) included β-lactam. Thirty-four patients (87.17%) were cured; five showed relapse. The final outcome (cure vs. relapse) showed a nonsignificant trend toward higher failure frequency among patients with previous prosthesis (OR: 6.89; 95% CI: 0.80-58.90) or prior surgery and infection (OR: 10.67; 95% IC: 1.08-105.28) in the same joint. Patients treated with clindamycin alone had a higher recurrence rate (40.0% vs. 8.8%). Rifampin treatment did not decrease recurrence in patients treated with β-lactams. Prior prosthesis, surgery, or infection in the same joint might be related to recurrence, and rifampin-based combinations do not seem to improve prognosis. Debridement and implant retention appear a safe option for surgical treatment of early PJI.

Orthopaedic Care of the Transgender Patient

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A transgender person is defined as one whose gender identity is incongruent with their biological sex assigned at birth. This highly marginalized population numbers over 1.4 million individuals in the U.S.; this prevalence skews more heavily toward younger generations and is expected to increase considerably in the future.

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Gender-affirming hormone therapy (GAHT) has physiologic effects on numerous aspects of the patient's health that are pertinent to the orthopaedic surgeon, including bone health, fracture risk, and perioperative risks such as venous thromboembolism and infection.

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Language and accurate pronoun usage toward transgender patients can have a profound effect on a patient's experience and on both objective and subjective outcomes.

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Gaps in research concerning orthopaedic care of the transgender patient are substantial. Specific areas for further study include the effects of GAHT on fracture risk and healing, outcome disparities and care access across multiple subspecialties, and establishment of perioperative management guidelines.

Periprosthetic Infection After Reverse Shoulder Arthroplasty: a Review

PURPOSE OF REVIEW

Periprosthetic infection is a relatively rare but potentially devastating complication after shoulder arthroplasty. The purpose of this article is to review the incidence, diagnosis, prevention, and management of periprosthetic infections after reverse shoulder arthroplasty, with a focus on literature published within the last 5 years.

RECENT FINDINGS

The 2018 International Consensus Meeting on Musculoskeletal Infection provides us with a framework for the diagnosis and management of periprosthetic infections after shoulder arthroplasty. Reverse shoulder arthroplasty has a higher reported rate of infection compared with anatomic total shoulder arthroplasty. Our current diagnostic tests do not appear to be as sensitive when compared with the hip and knee literature. Similar success has been reported with single and two-stage revision protocols, although prospective comparative data are lacking. The significance of unexpected positive cultures during revision arthroplasty remains unclear. We report current diagnostic and therapeutic options for periprosthetic infection after reverse shoulder arthroplasty. Much of the current literature does not distinguish between anatomic and reverse shoulder arthroplasty. Further high-level studies are warranted to refine these definitions and guide management.

Preoperative Skin Cultures Predict Periprosthetic Infections in Revised Shoulder Arthroplasties: A Preliminary Report

Current approaches do not provide a practical method for the accurate prediction of a Cutibacterium periprosthetic joint infection (PJI) in failed arthroplasties. Thus, surgeons revising failed arthroplasties must decide whether to exchange the implants and to institute antibiotic treatment without knowing the results of cultures of deep specimens obtained at the revision procedure. This study tests the hypothesis that the results of preoperative culture specimens of the skin surface obtained in the clinic can predict the presence of culture-positive Cutibacterium PJIs.

METHODS

Revision shoulder arthroplasties performed between October 3, 2017, and February 4, 2020, that had both preoperative clinic culture specimens and surgical culture specimens were included in this analysis. Culture results were assigned a value from 0 to 4. The percentage of the total skin bacterial load contributed by Cutibacterium (Cutibacterium percentage) was determined. To reduce concern about contamination, a robust criterion for culture-positive Cutibacterium PJI was applied: ≥2 surgical specimens with a Cutibacterium value of ≥1. The predictive values for a culture-positive Cutibacterium PJI were determined for a clinic skin culture Cutibacterium value of >1 and a clinic skin percentage of Cutibacterium of ≥75%.

RESULTS

Eighteen cases met the inclusion criteria; of these, 7 (6 male patients) met our criterion for a culture-positive Cutibacterium PJI. For all patients, a preoperative clinic skin Cutibacterium value of >1 predicted the presence of a culture-positive Cutibacterium PJI with an accuracy of 89%, and a clinic skin Cutibacterium percentage of ≥75% predicted the presence of a culture-positive Cutibacterium PJI with an accuracy of 94%. For male patients, a preoperative clinic skin Cutibacterium value of >1 predicted the presence of a culture-positive Cutibacterium PJI with an accuracy of 91%, and a clinic skin Cutibacterium percentage of ≥75% predicted the presence of a culture-positive Cutibacterium PJI with an accuracy of 100%.

CONCLUSIONS

A simple culture specimen of the unprepared skin surface obtained in a clinic prior to revision shoulder arthroplasty may provide valuable assistance to surgeons planning a revision arthroplasty.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.