Article

Contamination of the Surgical Field with Propionibacterium acnes in Primary Shoulder Arthroplasty

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Abstract

Background: Propionibacterium acnes is a common pathogen identified in postoperative shoulder infection. It has been shown to be present in culture specimens during primary shoulder arthroplasty; however, recent work has suggested that it is most likely to be a contaminant. Our aim was to identify the potential sources of contamination in shoulder arthroplasty. Methods: Tissue swabs were obtained for microbiological analysis from consecutive patients undergoing primary shoulder arthroplasty. Routine surgical technique was maintained, and 5 specimens were taken from different sites: (1) the subdermal layer, (2) the tip of the surgeon’s glove, (3) the inside scalpel blade (used for deeper incision), (4) the forceps, and (5) the outside scalpel blade (used for the skin incision). Results: Forty patients (25 female patients and 15 male patients) were included. Thirteen (33%) of the 40 patients had at least 1 culture specimen positive for P. acnes . Two (8%) of the 25 female patients and 11 (73%) of the 15 male patients had ≥1 culture specimen positive for P. acnes . The most common site of growth of P. acnes was the subdermal layer (12 positive samples), followed by the forceps (7 positive samples), the tip of the surgeon’s glove (7 positive samples), the outside scalpel blade (4 positive samples), and the inside scalpel blade (1 positive sample). There were 27 of 75 swabs that were positive on culture for P. acnes in male patients compared with 4 of 125 swabs in female patients. Male patients had 66 times (95% confidence interval, 6 to 680 times) higher odds of having a positive culture indicating subdermal colonization compared with female patients (p < 0.001). Conclusions: P. acnes is a common contaminant of the surgical field in primary shoulder arthroplasty. The subdermal layer may be the source of this contamination, and the prevalence of P. acnes in the surgical wound may be due to the surgeon’s manipulation with gloves and instruments. Our findings are consistent with those regarding the increased rates of P. acnes bacterial load and intraoperative growth in male patients compared with female patients. Clinical Relevance: P. acnes is likely to be spread throughout the surgical field from the subdermal layer via soft-tissue handling by the surgeon and instruments. Strategies need to be utilized to minimize this contact and to reduce the chance of colonization.

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... acnes), formerly named Propionibacterium acnes, is one of the most common causative organisms causing infection following shoulder surgery. [1][2][3][4] Multiple attempts have been made to provide consistent, reproducible methods of decolonization and/or eradication of this troublesome organism preoperatively in an effort to reduce the risk of surgical site contamination and infection. [5][6][7][8][9][10] Cutibacterium acnes is a slow-growing, facultative anaerobic grampositive bacillus commonly residing in the deep dermal layer of the skin within the pilosebaceous glands and hair follicles. ...
... [5][6][7][8][9][10] Cutibacterium acnes is a slow-growing, facultative anaerobic grampositive bacillus commonly residing in the deep dermal layer of the skin within the pilosebaceous glands and hair follicles. 4,5,9,11,12 This location not only makes C. acnes difficult to eradicate during surgical skin preparation because of poor penetration, but also puts the patient at risk of contamination of the shoulder joint due to repeated contact with this layer beneath the epidermis. 2,[4][5][6]10,11,13,14 It has been hypothesized that C. acnes inoculates the surgical wound once incision is made through the pilosebaceous glands. ...
... 4,5,9,11,12 This location not only makes C. acnes difficult to eradicate during surgical skin preparation because of poor penetration, but also puts the patient at risk of contamination of the shoulder joint due to repeated contact with this layer beneath the epidermis. 2,[4][5][6]10,11,13,14 It has been hypothesized that C. acnes inoculates the surgical wound once incision is made through the pilosebaceous glands. 11,15 Additional attempts have been made to decolonize the skin utilizing antibiotics, either systemically or via topical application, with varying degrees of success. ...
Article
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The purpose of this study was to examine the bactericidal efficacy of hydrogen peroxide (H2o2) on Cutibacterium acnes (C. acnes). We hypothesize that H2o2 reduces the bacterial burden of C. acnes. Methods The effect of H2o2 was assessed by testing bactericidal effect, time course analysis, growth inhibition, and minimum bactericidal concentration. To assess the bactericidal effect, bacteria were treated for 30 minutes with 0%, 1%, 3%, 4%, 6%, 8%, or 10% H2o2 in saline or water and compared with 3% topical H2o2 solution. For time course analysis, bacteria were treated with water or saline (controls), 3% H2o2 in water, 3% H2o2 in saline, or 3% topical solution for 5, 10, 15, 20, and 30 minutes. Results were analyzed with a two-way analysis of variance (AnoVA) (p < 0.05). Results Minimum inhibitory concentration of H2o2 after 30 minutes is 1% for H2o2 prepared in saline and water. The 3% topical solution was as effective when compared with the 1% H2o2 prepared in saline or water. The controls of both saline and water showed no reduction of bacteria. After five minutes of exposure, all mixtures of H2o2 reduced the percentage of live bacteria, with the topical solution being most effective (p < 0.0001). Maximum growth inhibition was achieved with topical 3% H2o2. Conclusion The inexpensive and commercially available topical solution of 3% H2o2 demonstrated superior bactericidal effect as observed in the minimum bactericidal inhibitory concentration, time course, and colony-forming unit (cFU) inhibition assays. These results support the use of topical 3% H2o2 for five minutes before surgical skin preparation prior to shoulder surgery to achieve eradication of C. acnes for the skin.
... The detection of C. acnes on surgical equipment was reported by Falconer et al 53 ; immediately after skin incision in shoulders without prior surgery, the investigators swabbed the subdermal layer, the surgeon's glove tip, the scalpel blades, and the forceps to determine possible vectors for introduction of this bacterium to the deep shoulder tissues. C. acnes was detected on at least 1 of these cultures in 40% of their patients, with the subdermal layer being the most common origin of positive cultures, followed by the surgeon's glove and forceps. ...
... To date, no clear association between phylotypes and infection/colonization or outcome of infection has been reported. 53 Considering this uncertainty about clinical relevance and utility and considering the high costs and limited availability in clinical microbiology laboratories, we suggest that C. acnes isolated in samples from the shoulder should not be routinely specified according to phylogroups. Rather, these techniques should be reserved for research purposes. ...
... The diagnosis of PJI is currently heavily reliant on culture results around the time of revision surgery. These culture results are frequently positivedoften unexpectedly 53,60,106,173 dand the implications have yet to be fully elucidated. 102,128,160,210 To understand the most effective methods for obtaining samples for culture, a systematic review of the existing literature was undertaken (Supplementary data). ...
Article
Full-text available
The Second International Consensus Meeting on Orthopedic Infections was held in Philadelphia, Pennsylvania, in July 2018. More than 800 experts from all 9 subspecialties of orthopedic surgery and allied fields of infectious disease, microbiology, and epidemiology were assembled to form the International Consensus Group. The shoulder workgroup reached consensus on 27 questions related to culture techniques , inflammatory markers, and diagnostic criteria used to evaluate patients for periprosthetic shoulder infection. This document contains the group's recommendations and rationale for each question related to evaluating periprosthetic shoulder infection.
... There has been a recent and growing recognition of this bacterium as a source of chronic or indolent infections of the shoulder. C. acnes is not only difficult to diagnose but also to treat as it generally takes 10-21 days to culture [69][70][71][72]. It generally leads to a low-level, indolent infection without gross purulence, erythema, or drainage. ...
... Standard surgical preps are also not effective at eliminating C. acnes preoperatively, and a significant amount of C. acnes burden persists despite standard skin preparation with up to 70% of skin cultures remaining C. acnes positive [69,70]. After a shoulder procedure has begun, persistent C. acnes has even been shown to grow on the surgical instruments being used in the case leading to another source of possible infection [72]. C. acnes infection/colonization is significantly associated with males more so than females. ...
... C. acnes infection/colonization is significantly associated with males more so than females. Males have shown a significantly higher odds of being colonized by C. acnes preoperatively, as well as intraoperative cultures being found positive [71,72]. ...
Article
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Purpose of review: Reverse total shoulder arthroplasty (RTSA) is a procedure that has been increasingly utilized since its inception over 20 years ago. The purpose of this review is to present the most up to date practice and advances to the RTSA literature from the last 5 years. Recent findings: Recent literature on RTSA has focused on identifying complications, maximizing outcomes, and determining its cost-effectiveness. RTSA has become a valuable tool in the treatment of various shoulder pathologies from fractures to massive-irreparable rotator cuff tears. Maximizing outcomes, proper patient counseling, and limiting complications are vital to a successful procedure. RTSA can be a difficult procedure; however, when utilized appropriately, it can be an invaluable tool in the orthopedic surgeon's armament. Recent evidence suggests, more and more, that RTSA not only provides value to the patient, but it is also cost-effective.
... Cutibacterium acnes (formerly Propionibacterium acnes) is an aerotolerant gram-positive bacillus that has been recognized as a significant pathogen in the genesis of acute and delayed periprosthetic joint infections (PJIs) in total shoulder, knee, and hip arthroplasty. [1][2][3][4][5][6][7] Rates of PJIs range from 0.7% to 4% for primary total shoulder arthroplasty (TSA) and up to 15% for revision arthroplasty, 7-12 with C. acnes being responsible for up to 70% of these infections. [13][14][15] Treating PJIs is challenging, often involving revision surgery, prolonged antibiotic use, and hospitalization, which can lead to increased costs and significant morbidity for the patient. ...
... Recent clinical studies have shown rates of contamination with C. acnes in primary TSA to be up to 33%, with contamination likely spreading from the subdermal layer. 6,27 Given the difficulty of excluding this region from the surgical field, recent efforts have focused on decontamination of the field after implant placement to decrease infection rates. [28][29][30][31][32] Topical use of vancomycin has been proposed as an adjuvant to decrease bacterial counts during procedures in which implants may predispose patients to infection with biofilm-forming bacterium. ...
Chapter
Cutibacterium acnes (formerly Propionibacterium acnes) is a significant pathogen in periprosthetic joint infections (PJIs) in total shoulder arthroplasty. Poor outcomes seen in PJIs are due to the established C. acnes bacterial biofilms. The prolonged nature of C. acnes infections makes them difficult to treat with antibiotics. The goal of this study was to determine the relative efficacy of vancomycin compared with penicillin and doxycycline against planktonic and mature biofilms. Clinical isolates from PJI patients as well as a laboratory strain of C. acnes were tested. Planktonic minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were obtained using modified clinical laboratory standard index assays. Biofilm MICs and MBCs were also obtained. The MIC was determined for both using the PrestoBlue viability stain. The MBC was determined using differential reinforced clostridial medium agar plates for colony-forming unit analysis. Using the PrestoBlue viability reagent, the planktonic MIC values for vancomycin were significantly higher than doxycycline. Across 10 strains of C. acnes, all three antibiotics had decreased efficacy when comparing planktonic and biofilm cultures. Although effective antibiotic doses ranged from 1 to 1,000 μg/mL, only doxycycline achieved inhibitory and bactericidal concentrations in all tested strains. Penicillin failed to achieve the minimum biofilm inhibitory concentration (MBIC) in 60% of tested strains, whereas vancomycin failed in 80% of tested strains. Penicillin, doxycycline, and vancomycin have similar abilities in inhibiting C. acnes growth planktonically. The MBIC for doxycycline was within the clinical dosing range, suggesting C. acnes biofilm offers minimal tolerance to these antibiotics. The MBIC for penicillin was within clinical dosing ranges in only 60% of trials, suggesting the relative tolerance of C. acnes to penicillin. The minimum biofilm bactericidal concentration (MBBC) of doxycycline showed efficacy in 90% of trials, whereas penicillin and vancomycin achieved MBBC in 15% of samples.
... P. acnes was reported to be involved in the pathology of shoulder arthropathy and in postsurgical outcomes [3e5]. In addition, a recent study suggests that P. acnes identified in the surgical field of a shoulder arthroplasty is a contaminant that derives from the surgical incision, the surgeon's gloves, and the surgical instruments [8]. ...
... However, positive cultures from the synovium and arthroscope swabs were detected at a significantly higher rate in Group P. A 15.8% detection rate has been reported in cultured skin swabs after skin preparation, as P. acnes colonizes the sebaceous glands rather than skin surface [11]. In addition, P. acnes has been detected from gloves and instruments used at surgery, and this could likely explain the possibility of contamination as the reason for detecting P. acnes from synovium swabs [8]. Mook et al. [12]. ...
Article
Background: Recently, Propionibacterium acnes was reported to be involved in postsurgical outcomes. We investigated the detection rate of P. acnes and clinical features of P. acnes infection following arthroscopic rotator cuff repair. Methods: Samples were collected from skin swabs before preparation, swabs of the synovium, sutures, and swabs from the arthroscope tip. We evaluated age, sex, presence of diabetes mellitus, preoperative contracture, operation time, blood test, Japanese Orthopaedic Association (JOA) scores, cuff integrity, deep infection, and positive inoculation rate. Results: We studied 90 patients (59 men and 31 women). Mean age was 60.6 years. Cultures of P. acnes showed a 65.5% positive superficial colonization rate (78.0%, male; 41.9%, female). Among the synovium swabs, P. acnes was detected in 13.6% and 0% of patients positive and negative for skin colonization with P. acnes, respectively. Positive culture was not correlated with age, sex, presence of diabetes mellitus, preoperative contracture, blood test, JOA score, cuff integrity, deep infection, operation time, and blood test date. Conclusions: P. acnes was detected at a higher rate in the skin of male patients. Patients with P. acnes detected on the skin showed higher rates of detection in the synovium. These findings suggest that the route of infection is via contamination. Level of evidence: Diagnostic level III; Case-control study.
... Owing to the inability of standard skin preparation solutions 65,99,109 and antibiotics 75,85,99 to eradicate bacteria (eg, C acnes) that exist underneath the skin surface, transection of the dermal structures can result in inoculation of bacteria into the deep tissues. 30 Therefore, in theory, previous nonarthroplasty surgery may introduce bacteria into deeper tissues and potentially increase the risk of PJI. ...
... 65,109 Therefore, any instrument transecting the skin surface and sebaceous glands can theoretically inoculate the deep tissues. 30 Four studies have directly investigated the effect of previous corticosteroid injections on the shoulder (''Search Methodology'' in Appendix): 1 database study, 1 clinical study, and 2 studies investigating deep cultures. Werner et al 131 performed a Medicare database study that compared 3 groups: arthroplasty within 3 months after injection, arthroplasty between 3 and 12 months after injection, and a control group. ...
Article
Full-text available
The Second International Consensus Meeting on Orthopedic Infections was held in Philadelphia, Penn-sylvania, in July 2018. Over 800 international experts from all 9 subspecialties of orthopedic surgery and allied fields of infectious disease, microbiology, and epidemiology were assembled to form a consensus workgroup. The following proceedings on the prevention of periprosthetic shoulder infection come from 16 questions evaluated by delegates from the shoulder section.
... P acnes has been the most common bacteria identified in intervertebral disc of patients with degenerative spine conditions, and it is frequently responsible for infection in other areas of the body, particularly the shoulder. 19,20 Its ubiquitous nature challenges the validity of results presented in prior studies. To evaluate the risk of contamination, Carricajo et al 4 conducted a study with 54 patients undergoing surgery for lumbar disc herniation. ...
... While P acnes has increasingly become of interest in the spine surgery, our findings seem to indicate that positive P acnes cultures are due to contamination rather than subclinical infection. [3][4][5]7,9,10,[19][20][21]23,24 Our study also shows that the presence of bacteria in intervertebral disc cultures is not associated with any complications related to infection on follow-up. ...
Article
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Study Design Prospective cohort study. Objectives To determine the prevalence of bacterial infection, with the use of a contaminant control, in patients undergoing anterior cervical discectomy and fusion (ACDF). Methods After institutional review board approval, patients undergoing elective ACDF were prospectively enrolled. Samples of the longus colli muscle and disc tissue were obtained. The tissue was then homogenized, gram stained, and cultured in both aerobic and anaerobic medium. Patients were classified into 4 groups depending on culture results. Demographic, preoperative, and postoperative factors were evaluated. Results Ninety-six patients were enrolled, 41.7% were males with an average age of 54 ± 11 years and a body mass index of 29.7 ± 5.9 kg/m ² . Seventeen patients (17.7%) were considered true positives, having a negative control and positive disc culture. Otherwise, no significant differences in culture positivity was found between groups of patients. However, our results show that patients were more likely to have both control and disc negative than being a true positive (odds ratio = 6.2, 95% confidence interval = 2.5-14.6). Propionibacterium acnes was the most commonly identified bacteria. Two patients with disc positive cultures returned to the operating room secondary to pseudarthrosis; however, age, body mass index, prior spine surgery or injection, postoperative infection, and reoperations were not associated with culture results. Conclusion In our cohort, the prevalence of subclinical bacterial infection in patients undergoing ACDF was 17.7%. While our rates exclude patients with positive contaminant control, the possibility of contamination of disc cultures could not be entirely rejected. Overall, culture results did not have any influence on postoperative outcomes.
... 24 The rates of positive intraoperative cultures differ based on the location of the specimen, with the subdermal layer being shown in previous studies to produce the highest proportion of positive culture growth. 4,12 Indolent infection with C acnes, when unrecognized or untreated, may explain postoperative findings of shoulder pain, stiffness, or implant loosening, even years after index shoulder arthroplasty. 19 Among the challenges in diagnosing C acnes infection are the slow-growing nature of the bacterium and the limited number of reliable diagnostic tools for predicting infection preoperatively. ...
... As demonstrated in several previous studies, we also found greater risk of positive cultures in male shoulders. 4,9,12,14,19,21,26,28 The remainder of the potential risk factors had no statistically relevant prediction to the likelihood of having positive intraoperative cultures. These included patient age, race, smoking status, body mass index, number or type of comorbidities, total number of prior ipsilateral shoulder surgeries, and the proportion of open (vs. ...
Article
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Background To our knowledge, the rate of positive intraoperative cultures in patients undergoing primary shoulder arthroplasty with prior ipsilateral nonarthroplasty shoulder surgery is unknown. The aim of this study was to determine the incidence and predictors of positive cultures in these patients. Methods We performed a retrospective review of patients with prior ipsilateral shoulder surgery with intraoperative cultures taken at the time of primary shoulder arthroplasty. We evaluated culture results, demographics, and number of prior surgeries. Regression analysis was used to determine patient-related risk factors that predict positive cultures. Results A total of 682 patients underwent primary shoulder arthroplasty, 83 had at least 1 prior ipsilateral shoulder surgery: 65.1% male, mean age 64.2 ± 10.9 years. For the cohort of 83 patients, an average of 3.2 ± 1.2 tissue samples were obtained for each patient, with a mean of 0.84 ± 1.14 tissue cultures being positive (range 0-5). Thirty-seven of the 83 patients (44.5%) had at least 1 positive culture, with Cutibacterium acnes the most frequent organism (31/37; 83.4%). An average of 1.9 ± 0.96 tissue cultures resulted positive (range 1-5) for the 37 patients who had positive cultures, 40.5% (15/37) had only 1 positive tissue culture (12/15 C acnes, 2/15 Staphylococcus epidermidis, and 1/15 vancomycin-resistant enterococcus). Male sex and history of prior shoulder infection were predictive of culture positivity (odds ratios: 2.5 and 20.9, respectively). Age, race, medical comorbidities, number of prior shoulder surgeries, and time from index shoulder surgery were not predictive of culture positivity. Conclusion About 45% of patients with no clinical signs of infection and a history of prior ipsilateral shoulder surgery undergoing primary shoulder arthroplasty grew positive intraoperative cultures. The significance of these findings remains unclear with regard to risk of periprosthetic infection and how these patients should be managed.
... Their observations support the overarching concept that the epidermis, dermis, and hair follicles are potential contamination sources of the C acnes culture positivity. 12,14,20,[27][28][29] In the case of C acnes positivity in one or more deep surgical samples, the question for the surgeon is whether there is an infection, possible indeterminate infection, or sample contamination. Probable infection should be made based on associating bacteriological and clinical findings. ...
... The rate of contamination from the native microbiome has been recorded ranging from 7% to 15% and has varied depending on the institution conducting this study. 14,15,20,[27][28][29][30][31] Currently, there is no definitive benchmark skin surface preparation proven to prevent inoculation of bacteria from the epidermal and dermal structures into the deep tissues at the time of the skin incision; however, hydrogen peroxide shows promise. 14,20 Additional research into preoperative skin preparation may aid in decreasing culture contamination and provide clarity to the C acnes UPC picture. ...
Article
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Introduction: The clinical significance and treatment recommendations for an unexpected positive Cutibacterium acnes (C acnes) culture remain unclear. The purpose of our study was to evaluate the clinical effect of a C acnes positive culture in patients undergoing open orthopaedic surgery. Methods: Patients with a minimum of one positive C acnes intraoperative culture were retrospectively reviewed over a 7-year period. True C acnes infection was defined as culture isolation from ≥1 specimens in the presence of clinical or laboratory indicators of infection. Results: Forty-eight patients had a positive intraoperative C acnes culture. 4.2% had a C acnes monoinfection, and 12.5% of the patients had a coinfection. The remainder was classified as indeterminate. Significant differences were identified between the indeterminate and true C acnes infection groups, specifically in patients with surgery history at the surgical site (P = 0.04), additional antibiotic therapy before surgery (P < 0 .001), and postoperative clinical signs of infection (P < 0 .001). Discussion: Suspicion for true C acnes infection should be raised in patients with surgery site history, antibiotic therapy before surgery, and clinical infectious signs. The indeterminate unexpected positive culture patients had a low risk of developing a true clinical infection that required antibiotic therapy.
... acnes), an indolent organism that is both a common causative organism in shoulder PJI but also a frequent contaminant, is one differentiating feature in the shoulder; specifically, C. acnes has been shown to persist on the skin and in the deep dermis despite standard skin preparations and also grow in sterile control specimens. 6,15,22,25,39 As such, a separate definition and criteria were proposed and accepted for shoulder arthroplasty at the 2 nd Annual ICM on Orthopaedic Infections (2018 ICM Shoulder). 10,11 Additionally, these consensus definitions allow for the diagnosis of PJI even in the setting of negative aspiration(s) and/or operative culture(s) if other criteria are met. ...
Article
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Purpose As the number of shoulder arthroplasty procedures performed rises yearly, so does the number of periprosthetic joint infections (PJIs). In this study, PJI consensus definitions were compared and contrasted in a series of revision shoulder arthroplasty cases preoperatively diagnosed as PJI. Understanding the variations in these definitions may guide PJI diagnoses, thereby improving treatment strategies and patient outcomes in the setting of infected shoulder arthroplasty. Methods All revision shoulder arthroplasty cases with preoperatively-diagnosed or suspected PJI (determined by procedure code) performed from 2008 – 2017 at a single institution by a single surgeon (fellowship-trained in shoulder and elbow surgery) were retrospectively evaluated. Following Institutional Review Board approval, patient demographic, treatment, and laboratory data were collected. Musculoskeletal Infection Society (MSIS; 2011) and International Consensus Meeting on Orthopaedic Infections (ICM; 2013, 2018 Revision, 2018 Shoulder) definitions of PJI were applied to the data. Statistical analysis assessed significant associations between culture status and PJI classification algorithm criteria. Results Thirty-seven patients with suspected PJI were identified; 24 culture-positive (CP) and 13 culture-negative (CN). In this series, the 2018 ICM Shoulder definition for definite infection was met at lower rates than all other definitions (CP; 71% vs. 96%; CN; 62% vs. 69%). 2018 ICM Shoulder major criteria showed stronger correlations to 2011 MSIS, 2013 ICM, and 2018 ICM Revision major criteria when “gross intra-articular pus” was excluded than when pus was included as a major criterion. 2018 ICM Revision cases determined to be infected were very strongly, positively, correlated with the 2018 ICM Shoulder cases determined to have definite or probable infections (ρ=1.000, p<0.0001). Additionally, cases classified as “definite” or “probable” infections with the 2018 ICM Shoulder definition were more likely to require reoperation for suspected recurrent infection after completion of antibiotic therapy. Conclusions In this series, the 2018 ICM Shoulder definition and previous PJI definitions classified cases as PJI at similar rates. However, the inclusion of a third major criterion of “gross intra-articular pus” weakened the correlation with prior definitions. Level of Evidence Level IV; Case Series
... 28 A growing body of literature has described the high incidence rates of deep and superficial colonization of the shoulder by C acnes following total shoulder arthroplasty and other open procedures. 8,19,36,37 Even less invasive procedures such as shoulder arthroscopy and shoulder injection have been associated with increased rates of deep tissue colonization. 4,7,31 This likely stems from the difficulty of eradicating C acnes through standard skin preparation and preoperative antibiotic administration. ...
Article
Background: The utility of next-generation sequencing (NGS) in differentiating between active infection and contaminant or baseline flora remains unclear. The purpose of this study is to compare NGS with culture-based methods in primary shoulder arthroplasty. Methods: A prospective series of primary shoulder arthroplasty patients with no history of infection or antibiotic use within 60 days of surgery was enrolled. All patients received standard perioperative antibiotics. After skin incision, a 10 × 3-mm sample of the medial skin edge was excised. A 2 × 2-cm synovial tissue biopsy was taken from the rotator interval after subscapularis takedown. Each sample set was halved and sent for NGS and standard cultures. Results: Samples from 25 patients were analyzed. Standard aerobic/anaerobic cultures were positive in 10 skin samples (40%, 95% confidence interval [CI] 20%-60%) and 3 deep tissue samples (12%, 90% CI 1%-23%]). NGS detected ≥1 bacterial species in 17 of the skin samples (68%, 95% CI 49%-87%) and 7 deep tissue samples (28%, 95% CI 9%-47%). There was a significant difference (P < .03) in the mean number of bacterial species detected with NGS between the positive standard culture (1.6 species) and the negative standard culture groups (5.7 species). Conclusion: NGS identified bacteria at higher rates in skin and deep tissue samples than standard culture did in native, uninfected patients undergoing primary procedures. Further research is needed to determine which NGS results are clinically relevant and which are false positives before NGS can be reliably used in orthopedic cases.
... Matsen et al. [10] collected 50 tissue samples from 10 patients undergoing primary SA without a history of prior surgery after aggressive prophylactic antibiotic and skin preparation and reported that 14% were positive for C. acnes. Falconer et al. [11] evaluated the contamination of the surgical fi eld by C. acnes in patients undergoing primary SA without history of prior surgery. The rate of one or more positive swab cultures was 33%. ...
Chapter
RECOMMENDATION: Obtaining tissue samples for culture in patients with history of prior non-arthroplasty surgery may be indicated in select cases. LEVEL OF EVIDENCE: Limited DELEGATE VOTE: Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus) Given the lack of evidence, the use of intraoperative tissue samples for cultures in patients undergoing primary SA with history of prior surgery as a screening infection test should be used at the discretion of the treating surgeon. No universal recommendation can be made at this time. However, considering that low-grade infections actually occur after arthroscopic and open shoulder surgeries and that prior surgery is a demonstrated risk factor for PJI, a screening strategy involving a selected group of patients based on the presence of risk factors (multiple prior surgeries; prior failed ORIF; male gender; younger) patients may be prudent
... 4,12 Despite preoperative skin preparation, viable C acnes persists in the dermal layer. 6,28 Phadnis et al hypothesize, from their findings of living bacteria in the dermal layer after skin incision, that C acnes is released during surgery and contaminates the surgical field as the surgeon cuts through the skin. 34 This was reconfirmed in our study by the swab after skin preparation (Swab 2 ), in which a proportion of subjects were found to have positive cultures and by the dermis cultures (Swab d and biopsies) that to some degree had living bacteria. ...
Article
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Introduction Most of the surgical site infections after shoulder surgery are caused by Cutibacterium acnes (C. acnes). Topically applied benzoyl peroxide (BPO) has for years been used to decrease the skin load of C. acnes in treatment of acne vulgaris. The purpose of the study was to examine this effect on bacterial colonization in patients subjected to elective shoulder surgery at different stages of the procedure. Methods 100 patients scheduled for primary elective open shoulder surgery were randomized to prepare either with BPO or according to local guidelines: with soap (control group). Four skin swabs were taken in a standardized manner at different times, before and after surgical skin preparation, one in dermis, and finally after the skin was sutured. Before skin incision five punch biopsies (3 mm in diameter and maximum 4 mm deep) were retrieved spaced 2 cm apart in the planned skin incision. Upon culturing quantification of C. acnes was made by serial dilutions. Results Men had a five-fold higher amount of C. acnes on untreated skin. Treatment with BPO considerably lowered this count (p=0.0001) both before and after skin disinfection compared to the control group. This positive effect of BPO persisted until skin closure, a point at which some recolonization of C. acnes had occurred, but to a higher degree in the control group (p=0.040). Conclusion Preoperative BPO-treatment of the shoulder may be an effective method to decrease bacterial skin load of C. acnes from skin incision until wound closure.
... C. acnes is abundant in the dermal layers of the skin limiting its eradication with topical skin preparations, and making interpretation of cultures from shoulder surgery difficult to interpret (1,2,(17)(18)(19)(20). Given that clinical and intraoperative signs of infection are commonly absent in C. acnes infections, cultures are currently considered as the "gold standard" for diagnosis of shoulder infections (21). This study detected a high rate (15%) of false positive cultures from samples taken from the room air during shoulder surgery. ...
Article
Background: Given high rates of positive Cutibacterium acnes (C. acnes) cultures in cases of both primary and revision shoulder surgery, the ramifications of positive C. acnes cultures remain uncertain. Next generation sequencing (NGS) is a molecular tool that sequences the whole bacterial genome and is capable of identifying pathogens and the relative percent abundance in which they appear within a sample. The purpose of this study was to report the false positive culture rate in negative control specimens and to determine whether NGS has potential value in reducing the rate of false positive results. Methods: Between April 2017 and May 2017 swabs were taken during primary shoulder arthroplasty. After surgical time out, using sterile gloves, a sterile swab was opened and exposed to the air for 5 seconds, returned to its contained, and sealed. One swab was sent to our institution's microbiology laboratory for aerobic and anaerobic culture and held for 13 days. The other sample was sent for NGS (MicroGen Dx, Lubbock, TX), where samples were amplified for pyrosequencing using a forward and reverse fusion primer and matched against a DNA library for species identification. Results: For 40 consecutive cases, swabs were sent for culture and NGS. C. acnes was identified by culture in 6/40 (15%) swabs and coagulase negative staphylococcus (CNS) was identified in 3/40 (7.5%). Both cases with positive NGS sequencing reported polymicrobial results with one sample (2.5%), including a relative abundance of 3% C. acnes. At 90 days after surgery, there were no cases of clinical infection in any of the 40 cases. Conclusion: We demonstrate that the two most commonly cultured organisms (C. acnes and CNS) during revision shoulder arthroplasty are also the two most commonly cultured organisms from negative control specimens. Contamination can come from air in the operating room or laboratory contamination.
... It is possible that multiple strains were inoculated into the surgical wound during the primary joint replacement procedure, or that some/all of the strains were translocated later on when the wound was still not completely healed. Another possibility is that some of the isolates represent a contamination during re-operation, rather than a true infection [29]. ...
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Prosthetic joint infections (PJIs) are rare but feared complications following joint replacement surgery. Cutibacterium acnes is a skin commensal that is best known for its role in acne vulgaris but can also cause invasive infections such as PJIs. Some phylotypes might be associated with specific diseases, and recently, a plasmid was detected that might harbour important virulence genes. In this study, we characterized C. acnes isolates from 63 patients with PJIs (n=140 isolates) and from the skin of 56 healthy individuals (n=56 isolates), using molecular methods to determine the phylotype and investigate the presence of the plasmid. Single-locus sequence typing and a polymerase chain reaction designed to detect the plasmid were performed on all 196 isolates. No statistically significant differences in sequence types were seen between the two study groups indicating that the C. acnes that causes PJIs originates from the patients own normal skin microbiota. Of the 27 patients with multiple tissue samples, 19 displayed the same sequence types among all their samples. Single-locus sequence typing identified different genotypes among consecutive C. acnes isolates from four patients with recurrent infections. The plasmid was found among 17 isolates distributed in both groups, indicating that it might not be a marker for virulence regarding PJIs. Patients presenting multiple sequence types in tissue samples may represent contamination or a true polyclonal infection due to C. acnes.
... [3][4][5] Furthermore, a recent study suggested that C. acnes may be a perioperative contaminant derived from surgical incisions, surgeon's gloves, and surgical instruments during shoulder arthroplasty. 10 Kajita et al 11 previously examined the detection rate of C. acnes in arthroscopic surgery. One of the problems that that the authors identified in this study was the use of a cannula for synovial swabs during arthroscopic surgery, and the possibility of washout from inadvertent reflux. ...
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In recent years, Cutibacterium acnes (C. acnes) has been reported to affect postoperative outcomes. The purpose of this study was to examine the detection rate and clinical features of C. acnes infection after open shoulder surgery. Fifty-nine patients (33 males and 26 females; mean age, 69.1 years) were included. Samples were collected from a skin swab at the incision site prior to skin preparation. Further samples were collected from synovial swabs at the glenohumeral joint immediately after incision and before incision closure. Samples with C. acnes-positive skin swab cultures were defined as Group A, and those with negative cultures were defined as Group N. Age, sex, presence of diabetes mellitus, operation time, presence of deep infection after surgery, and rate of positive synovial swab cultures were compared between groups. There were 27 patients in Group A (mean age 69.1±13.3 [SD], 21 males and 6 females) and 32 patients in Group N (mean age 69.1±11.0 [SD], 12 males and 20 females). No significant difference in the presence of diabetes mellitus and operation time were found between groups. From the glenohumeral joint immediately after incision, C. acnes was detected in 22.2% and 0% of patients in Group A and Group N, respectively. For the glenohumeral joint before incision closure, C. acnes was detected in 22.2% and 0% of patients in Group A and Group N, respectively, demonstrating a significantly higher rate in Group A. Our findings suggest that the route of infection following open shoulder surgery is via contamination.
... They concluded that C acnes was introduced into the shoulder during surgery because of the preponderance of positive cultures obtained from superficial and subdermal locations, compared with the relative paucity of positive cultures collected from deep tissues. 3 The same instruments were used for specimen collection, raising the potential for contamination. In this and similar studies, different culture methods and incubation times have been used, making it more difficult to clearly determine which positive cultures are significant and which are contaminants. ...
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Background Cutibacterium acnes is the most commonly isolated organism involved in periprosthetic shoulder infections. C acnes has traditionally been difficult to isolate, and much debate exists over appropriate culture methods. Recently, our institution initiated a 10-day culture method using a Brucella blood agar medium to enhance anaerobic growth specifically for C acnes in shoulder specimens. Methods A retrospective review of shoulder cultures from 2014-2017 of patients undergoing workup for possible infected shoulder arthroplasty was performed. Cultures were obtained in patients either preoperatively or intraoperatively at the time of revision. Presence of infection was determined based on at least 1 positive culture and treatment with either prolonged antibiotics, placement of an antibiotic spacer at the time of revision, or repeat surgical débridement. Results The records of 85 patients with 136 cultures were reviewed. Eighty-two patients had full records with at least 1-year clinical follow-up. Fifty-eight cultures were positive, with C acnes as the most commonly recovered organism (57% of positive cultures). Clinical follow-up of patients with negative cultures found no incidence of missed periprosthetic infection. Conclusions Use of a 10-day culture incubation method to enhance anaerobic bacterial growth is able to accurately detect periprosthetic infection in the shoulder including those related to C acnes. Our results suggest that by adopting more uniform culture methods, a shorter culture incubation time may be adequate. Ultimately, prospective studies with rigorous microbiologic methods are needed to best understand the clinical significance of unexpected positive bacterial cultures in shoulder arthroplasty.
... Falconer et al 19 pursued this idea in a prospective case series involving 40 patients undergoing primary total shoulder replacement. Five swabs were taken during surgery from sites of potential contamination. ...
Article
Cutibacterium acnes is a lipophilic, anaerobic, gram-positive bacillus that mainly colonizes the pilosebaceous glands of human skin. It has been implicated as the leading cause of prosthetic joint infection (PJI) after shoulder arthroplasty. However, PJI caused by C acnes rarely manifests as overt clinical, laboratory, or imaging features. In fact, more than 40% of shoulders undergoing revision arthroplasty are likely to be culture positive. However, rates of infection following a positive culture can be as low as 5%. The purpose of this review was to put forth alternative explanations for this discordance between positive cultures and infection. We describe C acnes roles as a commensal, bystander, and/or contaminant organism; the role of cultures in diagnosis and other methods that may be more accurate; its existence in a shoulder microbiome; and the variable virulence of C acnes. C acnes is an important cause of shoulder PJI in some patients. However, there is a large body of literature that suggests other functions that need to be considered. Further research is needed to define the role of C acnes that is logically explained by all of the literature and not only some.
... It has been suggested that a second change of gloves for the surgeon and re-draping, use of a skin barrier, along with hair removal by electric clippers or depilatories, could reduce C. acnes infection. 2,10,40 Another preventative method being utilized is the application of vancomycin powder during shoulder arthroplasty to prevent C. acnes infection. 25 This was found to be highly cost effective. ...
Article
Infection is a rare but serious complication of shoulder arthroplasty. The most prevalent cause of patient infections is Cutibacterium acnes (formerly Proprionibacterium acnes), a commensal skin bacterial species. Its presentation is often non-specific and can occur long after shoulder arthroplasty, leading to delay in diagnosis. This bacterium is difficult to culture, typically taking 14 to 17 days for a positive culture and often does not exhibit abnormal results on a standard laboratory workup for infection (eg, ESR, CRP, and synovial WBC count). Male patients are at particularly high-risk due to having a greater number of sebaceous follicles than females. While it is difficult to diagnose, early diagnosis can lead to decreased morbidity, appropriate treatment, and improved clinical outcomes. Current options for treatment include antibiotics, one stage implant exchange, or two stage implant exchange, although success rates of each are not currently well described. A better understanding of the prevention, diagnosis, and treatment of C. acnes infection could lead to better patient outcomes from shoulder arthroplasty.
... It is the most common bacterium found in the deep tissues at the time of revision shoulder arthroplasty performed for pain, stiffness, and component loosening (3). Because common skin preparations and antibiotics given around the time of surgery fail to completely eradicate the bacteria (5)(6)(7)(8)(9), particularly those under the skin surface, transection of the dermal structures can lead to inoculation of C. acnes (and related Cutibacterium species) into the deeper tissues and implants at the time of the original shoulder arthroplasty (10,11). Over time, these slow-growing bacteria are believed to be responsible for arthroplasty failure resulting in a need for a revision surgery. ...
Article
Introduction : Cutibacterium acnes is the most common bacterium associated with periprosthetic shoulder infections. Sequencing of C. acnes has been proposed as a potential rapid diagnostic tool and a method of determining subtypes associated with pathogenicity and antibiotic resistance patterns. When multiple deep samples from the same surgery are culture positive for the same species, and the isolates show the same culture phenotype, it is typically assumed that these isolates are clonal. However, it is well known that C. acnes is not clonal on the skin of most individuals. We hypothesized that the C. acnes recovered at the time of revision shoulder arthroplasty would often represent more than one subtype and we tested this hypothesis in this work. Methods : For patients undergoing revision shoulder arthroplasty multiple samples from the surgical field were taken. For those patients with multiple samples that were culture positive for C. acnes , isolates from each sample were subjected to full genome sequencing. Results : Of 11 patients, five (45%) had different subtypes of C. acnes within the deep tissues even though the colony morphology was similar. One patient had four subtypes in the deep tissues, while four had two different subtypes. Conclusion: Up to 4 different subtypes of Cutibacterium acnes were observed in the deep tissues of a single patient. Clonality of C. acnes isolates from deep specimens from a potential periprosthetic shoulder infection cannot be assumed. Sequence-based characterization of virulence and antibiotic resistance may require testing of multiple deep specimens.
... Due to its slow-growth phenotype and anaerobic growth requirement, it is only recently being appreciated as a clinically relevant pathogen due to improvements in culturing techniques. It is being isolated with increasing frequency during both primary and revision shoulder arthroplasty and instrumented spinal surgery, in numbers approaching 40% when recovered from explanted hardware [9][10][11][12][13]. Several recent publications have noted the presence of C. acnes in intervertebral disc tissue even before surgery, presumably due to tissue invasion following trauma at the site [14][15][16][17]. ...
Article
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Aim: The most common risk associated with intradiscal injection of platelet-rich plasma (PRP) is discitis with Cutibacterium acnes. It is hypothesized that antimicrobial activity of PRP can be enhanced through inclusion of leukocytes or antibiotics in the injectate. Materials & methods: Multiple PRP preparations of varying platelet and leukocyte counts were co-cultured with C. acnes with or without cefazolin, with viable bacterial colony counts being recovered at 0, 4, 24 and 48 hours post-inoculation. Results: A direct correlation between C. acnes recovery and granulocyte counts were observed. Conclusion: We observed the greatest antimicrobial activity with the leukocyte-rich, high platelet PRP preparation combined with an antibiotic in the injectate. However, cefazolin did not completely clear the bacteria in this assay.
... acnes), formerly known as Propionibacterium acnes, is the most commonly detected pathogen during shoulder surgery [1][2][3][4][5]. It is suggested that C. acnes can contaminate the surgeon's instruments or gloves when the sebaceous glands are cut [6] and can in that way contaminate the wound. When a low-grade infection is present, it can result in unexplained pain and stiffness, dysfunctional joints, or loosening of shoulder prostheses, which can affect patient outcomes [7][8][9]. ...
Article
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IntroductionLow-grade Cutibacterium acnes (C. acnes) infections after shoulder surgery usually result in unexplained complaints. The absence of clinical signs of infection makes the incidence unclear and underreported. This study aimed to determine the incidence of C. acnes infections in patients with artificial material and unexplained persistent shoulder complaints. We hypothesized that the incidence of C. acnes infections would be higher in patients with artificial material. Risk factors and associations between culture time and contaminations/infections were also assessed.Materials and methodsThis retrospective cohort study included patients with and without artificial material undergoing revision shoulder surgery for persistent complaints after primary surgery and the suspicion of a low-grade infection. Three–six cultures were taken in all patients. C. acnes infection incidence was determined and logistic regression analysis was performed to identify risk factors. The association between time to culture growth and infections/contaminations was evaluated using Kaplan–Meier analysis and log-rank test.Results26/61 (42.6%) patients with and 14/33 (42.2%) without material had a C. acnes infection. Age (OR 0.959; 95% CI 0.914–1.000) and BMI (OR 0.884; 95% CI 0.787–0.977) were risk factors. Time to C. acnes culture positivity was not different between infections and contaminations.Conclusion The incidence of C. acnes infections was 42.6% in patients with artificial material and 42.2% in patients without artificial material. Younger age and lower BMI are risk factors. Low-grade C. acnes infections should be considered in patients with unexplained persistent complaints following shoulder surgery.
Article
Background: We evaluated the detection rate for Cutibacterium acnes (C. acnes) in patients who underwent arthroscopic cuff repair and Bankart repair. Methods: Arthroscopic cuff repair was performed in 105 patients (R group) and arthroscopic Bankart repair was performed in 29 patients (B group). Skin swabs prior to antisepsis, intraoperative synovial swabs of the glenohumeral joint (immediately after incision and prior to wound closure), suture of suture anchor, and postoperative swabs from the tip of arthroscope were cultured. Evaluation criteria were compared between groups and included the presence or absence of diabetes mellitus, operation time, frequency of preoperative injections, deep infections, and detection rate of C. acnes in multiple regions of the body. Results: There were 14 patients (12.2%) in the R group and one patient in the B group (3.6%) with diabetes mellitus, and no significant difference was found between the two groups. The frequency of injections to the shoulder was significantly greater in the R group at 3.6 ± 4.2 times compared to the B group at 1.6 ± 2.0 times. There were no deep infections in either groups. The detection rate for C. acnes was significantly greater in the synovial swabs alone (skin swabs for R and B groups, 42.3% and 47.6%, respectively; synovial swabs, 10.4% and 1.8%; suture, 8.7% and 0%; tip of arthroscope, 4.3% and 0%). Conclusions: A significantly greater number of C. acnes samples were detected from synovial swabs of cuff tears, suggesting that its presence may be due to preoperative injections to the shoulder.
Article
Background Diagnosis and treatment of shoulder periprosthetic joint infection is a difficult problem. The purpose of this study was to utilize the 2018 International Consensus Meeting definition of shoulder periprosthetic joint infection to categorize revision shoulder arthroplasty cases and determine variations in clinical presentation by presumed infection classification. Methods Retrospective review of patients undergoing revision shoulder arthroplasty at a single institution. Likelihood of periprosthetic joint infection was determined based on International Consensus Meeting scoring. All patients classified as definitive or probable periprosthetic joint infection were classified as periprosthetic joint infection. All patients classified as possible or unlikely periprosthetic joint infection were classified as aseptic. The periprosthetic joint infection cohort was subsequently divided into culture-negative, non-virulent microorganism, and virulent microorganism cohorts based on culture results. Results Four hundred and sixty cases of revision shoulder arthroplasty were reviewed. Eighty (17.4%) patients were diagnosed as definite or probable periprosthetic joint infection, of which 29 (36.3%), 39 (48.8%), and 12 (15.0%) were classified as virulent, non-virulent, or culture-negative periprosthetic joint infection, respectively. There were significant differences among periprosthetic joint infection subgroups with regard to preoperative C-reactive protein (p = 0.020), erythrocyte sedimentation rate (p = 0.051), sinus tract presence (p = 0.008), and intraoperative purulence (p < 0.001). The total International Consensus Meeting criteria scores were also significantly different between the periprosthetic joint infection cohorts (p < 0.001). Discussion While the diagnosis of shoulder periprosthetic joint infection has improved with the advent of International Consensus Meeting criteria, there remain distinct differences between periprosthetic joint infection classifications that warrant further investigation to determine the accurate diagnosis and optimal treatment.
Article
Background: Cutibacterium are the most common cause of periprosthetic shoulder infections, as defined by ≥2 deep cultures. Established Cutibacterium periprosthetic infections cannot be resolved without prosthesis removal. However, the decision for implant removal must be made from an assessment of infection risk before the results of intraoperative cultures are finalized. We hypothesized that the risk for a Cutibacterium infection is associated with characteristics that are available at the time of revision arthroplasty. Methods: In a retrospective review of 342 patients having prosthetic revisions between 2006 and 2018 for whom definitive deep culture results were available, we used univariate and multivariate analyses to compare the preoperative and intraoperative characteristics of 101 revisions with Cutibacterium periprosthetic infections to the characteristics of 241 concurrent revisions not meeting the definition of infection. Results: Patients with definite Cutibacterium periprosthetic infections were younger (59 ± 10 vs. 64 ± 12, P < .001), were more likely to be male (91% vs. 44%, P < .001), were more likely to have had their index procedure performed for primary osteoarthritis (54% vs. 39%, P = .007), were more likely to be taking testosterone supplements (8% vs. 2%, P = .02), had lower American Society of Anesthesiologists scores (1.9 ± 0.7 vs. 2.3 ± 0.7, P < .001), and had lower body mass indices (29 ± 5 vs. 31 ± 7, P = .005). Patients with definite Cutibacterium periprosthetic infections also had significantly higher preoperative loads of Cutibacterium on their unprepared skin surface (1.7 ± 0.9 vs. 0.4 ± 0.8, P < .001) and were more likely to have the surgical finding of synovitis (41% vs. 16%, P < .001). Conclusions: The risk of definite Cutibacterium periprosthetic infections is associated with observations that can be made before or at the time of revision arthroplasty.
Article
Background : The total joint literature has shown promising results of bisphosphonate use on decreasing early bone loss after hip and knee arthroplasty and reducing aseptic revision risk though a higher risk of periprosthetic fracture has also been reported. We sought to evaluate the association between bisphosphonate use and aseptic revision risk in patients undergoing shoulder arthroplasty. Methods : A United States integrated healthcare system's registry was used to identify 6204 patients who underwent primary elective shoulder arthroplasty for osteoarthritis (2005-2016). Preoperative bisphosphonate users (defined as having at ≥6-month supply and 80% adherence) were compared to non-bisphosphonate users. Multivariable Cox proportional hazard regression was used to evaluate aseptic revision risk according to bisphosphonate use while adjusting for confounders. Secondary analysis stratified by age (40-64, ≥65 years) and bone quality status (normal, osteopenia, osteoporosis, or unknown). Results : At the time of index procedure, 564 (9.1%) were considered as bisphosphonate users. We failed to observe a difference in aseptic revision risk by bisphosphonate use (hazard ratio [HR]=0.92, 95% confidence interval [CI]=0.50-1.72). No association was observed even after stratifying by bone quality and age. No revisions for periprosthetic fracture occurred in the bisphosphonate user group during follow-up. Conclusions : While prior studies in lower extremity joint arthroplasty cohorts have observed a differential risk for revision surgery with bisphosphonate use, we failed to observe any associations between bisphosphonate use and revision risk in a cohort of shoulder arthroplasty patients. Level of Evidence : Level III
Article
Introduction Cutibacterium acnes is a recognized culprit for implant-associated infections, but positive cultures do not always indicate clinically relevant infection. Studies have shown a correlation between the β-hemolytic phenotype of C. acnes and its infectious capacity, but correlation with genetic phylotype has not been performed in literature. The purpose of this study is to evaluate β-hemolysis phenotype, genetic phylotype, and mid-term clinical outcomes of C. acnes isolated from orthopedic surgical sites. Methods Fifty-four C. acnes isolates previously obtained from surgical wounds of patients undergoing hip, knee, shoulder, or spine implant removal were re-cultured. There were 21 females and 33 males with an average age of 59 years (range, 18–84). Twenty-four were from clinically infected sites whereas 30 were considered contaminants. De novo β-hemolysis was analyzed and a retrospective chart review was performed to evaluate clinical outcomes at 7.1 years (range, 0.1–12.8). Results On Brucella agar with 5% rabbit blood, 46% of contaminant and 43% of infectious isolates were hemolytic. Type II phylotype was significantly more nonhemolytic regardless of infectious or contaminant status (p < 0.05). Type 1B correlated with a hemolytic-infectious phenotype and Type 1A with a hemolytic-contaminant phenotype but was not statistically significant. Conclusion The β-hemolytic profile of C. acnes did not correlate with phylotype or clinically relevant orthopedic infection.
Article
Background: Reducing intraoperative wound contamination is a critical preventive strategy for reducing the risk of prosthetic joint infection in shoulder arthroplasty. The aim of this study was to investigate the potential microbial colonization of subscapularis tagging sutures during shoulder arthroplasty. Methods: In this prospective study, 50 consecutive patients undergoing primary shoulder arthroplasty (anatomic or reverse) were enrolled. Patients with revision shoulder arthroplasty and proximal humeral fractures were excluded. Nonabsorbable, braided tagging sutures were placed through the subscapularis tendon prior to tenotomy. A similar nonabsorbable, braided suture (control) was placed in a sterile container on the back table, open to the operating room environment. Subscapularis tagging sutures (experimental specimens) and control sutures were collected prior to subscapularis tenotomy repair and submitted for aerobic and anaerobic cultures. Cultures were held for 21 days to account for extended growth of slow-growing bacteria. Results: A total of 12 of 50 experimental and 16 of 50 control sutures had positive cultures. Staphylococcus epidermidis and Cutibacterium acnes were the 2 most commonly isolated organisms. Active tobacco use (P = .038) and procedure length (P = .03) were significantly associated with positive cultures. No significant association between positive subscapularis tagging suture cultures and positive control cultures was found (P = .551). Patient age, sex, body mass index, and significant medical comorbidities were not significantly associated with positive cultures. Discussion: Subscapularis tagging sutures are a potential source of microbial contaminant in shoulder arthroplasty, and we recommend exchanging the tagging suture with a suture opened immediately prior to subscapularis repair.
Article
Cutibacterium (formerly Propionibacterium) acnes is an important for not only exacerbating factor of acne vulgaris but also pathogen of surgical site infections (SSIs) in orthopedics and plastic surgery. Although biofilm-forming (BF) C. acnes are associated with intractable SSI, characteristics of these strains were still unknown. Here, we explored detailed molecular epidemiological features of BF C. acnes isolated as causative pathogen of infectious diseases. Phylogenetic types of 205 C. acnes strains isolated between 2013 and 2018 from 18 clinical departments of a university hospital in Japan were determined by single-locus sequence type (SLST). Clade H (traditional type IC) and K (type II) which are less relevant with healthy skin and acne vulgaris, were detected in 26.8% (55/205) and 16.1% (33/205) of the strains, respectively. The incidence of them was significantly higher than that of acne patients (H and K, each 2.9%, P < 0.05). In addition, SLST distribution of C. acnes strains differed by each department and isolation site. When biofilm formation was quantified, 51 strains (24.9%) were defined as high-BF strains. Notably, most high-BF strains were classified into the strains of clade H (56.4%, 31/55) and clade K (54.4%, 18/33), and these strains were frequently found in the strains isolated from patients of medical emergency center and plastic surgery. Similarly, high-BF strains were frequently found among the isolates from blood (35.7%) and catheters (30.0%), with a high proportion belonging to clades H and K. Compared to C. acnes strains isolated from acne patients, antimicrobial-resistant strains were less identified in non-acne patients. Our findings showed that pathogenicity of C. acnes strains differs by their phylogenetic types. Furthermore, we showed clade H and K have the ability of high biofilm formation and suggest that these strains have potential to become a risk factor for SSI.
Article
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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. Methods: In 51 patients undergoing shoulder arthroplasties, total serum testosterone, free testosterone, and sex hormone binding globulin levels obtained in the clinic before the surgical procedure were compared with the levels of Cutibacterium on the skin in clinic, on the skin in the operating room prior to the surgical procedure, and on the dermal wound edge of the incised skin during the surgical procedure. Results: Clinic skin Cutibacterium loads were strongly associated with both clinic free testosterone levels (tau, 0.569; p < 0.001) and total serum testosterone levels (tau, 0.591; p < 0.001). The prepreparation skin and wound Cutibacterium levels at the time of the surgical procedure were also significantly associated with both the clinic total serum testosterone levels (p < 0.001) and the clinic free testosterone levels (p < 0.03). A multivariate analysis demonstrated that serum testosterone was an independent predictor of high skin Cutibacterium loads, even when age and sex were taken into account. Patients taking supplemental testosterone had higher free testosterone levels and tended to have higher skin Cutibacterium loads. Patients who underwent the ream-and-run procedure had higher total and free testosterone levels and higher skin Cutibacterium loads. Conclusions: Testosterone levels are predictive of skin Cutibacterium levels in patients undergoing shoulder arthroplasty. This relationship deserves further investigation both as a risk stratification tool and as a potential area for intervention in reducing shoulder periprosthetic joint infection. Level of evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.
Article
Proprionibacterium (Cutibacterium)acnes is the organism most commonly associated with deep infection after shoulder surgery, including shoulder arthroplasty. It is abundant in the sebaceous follicles of the axilla and skin around the shoulder girdle, being implicated in the pathology of acne. It is adapted to the environment of the hair follicle, where it secretes enzymes that digest sebum and provide nutrients. However in this location it is unaffected by skin preparation immediately prior to the skin incision and can therefore be carried into deeper layers Indeed, it is so commonly found in the deep tissues around the shoulder in cases with no suspected infection that the line between contaminant and pathogen can be extremely difficult to draw. To add to this, it is slow growing and culture in anaerobic conditions often does not yield a positive result until the second week of culture or later. An understanding of the organism and its impact on shoulder surgery is therefore crucial to those operating in this region.
Article
Background: Preoperative skin preparations for total shoulder arthroplasty (TSA) are not standardized for Cutibacterium acnes eradication. Topical benzyl peroxide (BPO) and benzyl peroxide with clindamycin (BPO-C) have been shown to reduce the bacterial load of C acnes on the skin. Our aim was to investigate whether preoperative application of these topical antimicrobials reduced superficial colonization and deep tissue inoculation of C acnes in patients undergoing TSA. Methods: In a prospective, single-blinded randomized controlled trial, 101 patients undergoing primary TSA were randomized to receive either topical pHisoHex (hexachlorophene [1% triclosan; sodium benzoate, 5 mg/mL; and benzyl alcohol, 5 mg/mL]) (n = 35), 5% BPO (n = 33), or 5% BPO with 1% clindamycin (n = 33). Skin swabs obtained prior to topical application and after topical application before surgery, as well as 3 intraoperative swabs (dermis after incision, on joint capsule entry, and dermis at wound closure), were cultured. The primary outcome was positive culture findings and successful decolonization. Results: All 3 topical preparations were effective in decreasing the rate of C acnes. The application of pHisoHex reduced skin colonization by 50%, BPO reduced skin colonization by 73.7%, and BPO-C reduced skin colonization by 81.5%. The topical preparation of BPO-C was more effective in decreasing the rate of C acnes at the preoperative and intraoperative swab time points compared with pHisoHex and BPO (P = .003). Failure to eradicate C acnes with topical preparations consistently resulted in deep tissue inoculation. There was an increase in the C acnes contamination rate on the skin during closure (33%) compared with skin cultures taken at surgery commencement (22%). Conclusion: Topical application of BPO and BPO-C preoperatively is more effective than pHisoHex in reducing colonization and contamination of the surgical field with C acnes in patients undergoing TSA.
Article
Background: When performing revision shoulder arthroplasty, surgeons do not have access to the results of intraoperative culture specimens and will administer empiric antibiotics to cover for the possibility of deep infection until the culture results are finalized. The purpose of this study was to report the factors associated with the initiation, modification, and adverse events of 2 different postoperative antibiotic protocols in a series of revision shoulder arthroplasties. Methods: In this study, 175 patients undergoing revision shoulder arthroplasty were treated with either a protocol of intravenous (IV) antibiotics if there was a high index of suspicion for infection or a protocol of oral antibiotics if the index of suspicion was low. Antibiotics were withdrawn if cultures were negative and were modified as indicated if the cultures were positive. Antibiotic course, modification, and adverse effects to antibiotic administration were documented. Results: On univariate analysis, factors significantly associated with the initiation of IV antibiotics were male sex (p < 0.001), history of infection (p < 0.001), intraoperative humeral loosening (p = 0.003), and membrane formation (p < 0.001). On multivariate analysis, male sex (p = 0.003), history of infection (p = 0.003), and membrane formation (p < 0.001) were found to be independent predictors of the initiation of IV antibiotics. On the basis of preoperative and intraoperative characteristics, surgeons anticipated the culture results in 75% of cases, and modification of antibiotic therapy was required in 25%. The modification from oral to IV antibiotics due to positive culture results was made significantly more often in male patients (p < 0.001). Adverse effects of antibiotic administration occurred in 19% of patients. The rates of complications were significantly lower in the patients treated with oral antibiotics and a shorter course of antibiotics (p < 0.001). Conclusions: Complications associated with antibiotic administration after revision shoulder arthroplasty are not infrequent and are more common in patients whose initial protocol is IV antibiotics. Further study is needed to balance the effectiveness and risks of post-revision antibiotic treatment given the frequency of antibiotic-related complications. Level of evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Article
Background: We evaluated the detection rate of Cutibacterium acnes (C. acnes) for patients who underwent arthroscopic Bankart repair for traumatic anterior shoulder instability. Methods: Study subjects included 36 patients who underwent arthroscopic Bankart repair. Skin swabs prior to antisepsis, intraoperative synovial swabs of the glenohumeral joint (immediately after incision and prior to wound closure), and the suture of the suture anchor were cultured. Evaluation criteria included the detection rate of C. acnes in multiple regions of the body. Results: Using a skin swab culture test, C. acnes was detected in 63 of 108 samples (58.3%). The bacterium was detected in 2 of 36 samples (5.5%) and 4 of 36 (11.1%) in the synovial swab culture of the glenohumeral joint immediately after surgical incision and immediately before wound closure, respectively. In the suture culture of the suture used in the arthroscopic Bankart repair, C. acnes was detected in 1 of 36 samples (2.8%). Conclusions: C. acnes was detected in patients undergoing surgeries for shoulder instability. The relationship between C. acnes and the pathological condition of shoulder instability remains unknown.
Article
Purpose Chlorhexidine showers prior to shoulder arthroplasty are commonly recommended by surgeons to lower the risk of periprosthetic infection; however, the effectiveness of these washes in eliminating bacteria from the skin of the shoulder has not been thoroughly evaluated. The objective of this study was to determine the degree to which pre-operative chlorhexidine washes effectively eliminate bacteria from the epidermal skin surface and from the dermis freshly incised during shoulder arthroplasty. Methods Around 66 patients undergoing primary shoulder arthroplasty were instructed to shower with chlorhexidine before surgery. Each patient had three skin swabs: (1) the epidermis at a pre-operative clinic appointment, (2) the epidermis at surgery after home chlorhexidine showers but prior to skin preparation, and (3) the dermis after incision of the prepared skin. The bacterial loads of Cutibacterium and other bacterial types from each swab were compared to determine whether the showers were effective in altering the bacterial loads. Results Chlorhexidine washes were effective in reducing the skin load of other bacterial species (p < 0.005), but they did not decrease the skin load of Cutibacterium (p = 0.585). Conclusions Pre-operative skin showers with chlorhexidine were not effective in reducing the load of Cutibacterium on the skin of patients having shoulder arthroplasty. Since Cutibacterium is responsible for the highest percentage of shoulder periprosthetic infections, research is needed to identify more effective means of removing these bacteria from the surgical field.
Article
Introduction Cutibacterium acnes is one of the major pathogens responsible for infection after shoulder surgery. Surgical dissection of the dermis may expose C. acnes from sebum-producing hair follicles. Due to contact with surgeon's gloves and instruments these are further spread throughout the surgical field. The purpose of this study was to determine if subcutaneous tissue disinfection could reduce the C. acnes culture rate in primary open shoulder surgery. Methods All patients eligible for primary open shoulder surgery using a deltopectoral approach were prospectively enrolled in our 2-arm randomized, single blinded clinical trial. In all patients a skin swab of the operative field was taken prior to standard surgical skin preparation. After exposure of the deltoid fascia, the disinfection group received an additional preparation of the subcutaneous layer with povidone-iodine solution. Once the proximal humerus was completely exposed, 5 swabs from different sites were taken for microbiological examination according to a strict specimen collection protocol. All cultures were incubated in aerobic and anaerobic conditions for 14 days. Results Between February 2019 and December 2019, 108 patients were enrolled in two groups (70 treatment vs 38 control). The two groups did not show any significant difference in terms of gender, age, BMI or occurrence of diabetes. The subcutaneous disinfection protocol reduced significantly the positive culture rate of the operating field for all germs combined (p = 0.036) and specifically for C. acnes (p = 0.013). The reduction of positive swabs for C. acnes was significant for the surgeon's gloves (p = 0.041) as well as for the retractors (p = 0.007). Conclusion Disinfection of the subcutaneous tissue significantly reduced the C. acnes culture rate during primary open shoulder surgery. We highly recommend this simple step as adjunct to the current surgical practice in order to limit iatrogenic contamination of the surgical field. Future studies may observe a reduction in postoperative shoulder infection due to this practice.
Article
Cutibacterium acnes is the most prevalent cause of joint infection after shoulder surgery. Current methods for decolonizing this bacterium from the shoulder region have proved ineffective owing to its unique niche within dermal sebaceous glands and hair follicles. When we are making decisions to decolonize the skin of C acnes, the risks associated with decolonization must be balanced by the potential benefits of reduced deep tissue inoculation. The purpose of this review was to describe currently available methods of decolonization and their efficacy.
Article
Background Unexpected positive cultures (UPCs) are very commonly found during shoulder arthroplasty when surgeons send intraoperative cultures to rule out periprosthetic joint infection (PJI) without clinical or radiographic signs of infection. Cutibacterium acnes is thought to be the most common bacteria cultured in this setting; however, the implications of an unexpected positive result are neither well-defined nor agreed upon within the literature. The current review evaluates the incidence of UPC and C. acnes in reverse total arthroplasty, the clinical significance, if any, of these cultures, and various prognostic factors that may affect UPC incidence or recovery following PJI. Methods A systematic review was performed with PRISMA guidelines using PubMed, CINAHL, and Scopus databases. Inclusion criteria included studies published from Jan 1, 2000 and May 20,2021 that specifically reported on UPCs, native or revision shoulder surgery, and any study that directly addressed one of our six proposed clinical questions. Two independent investigators initially screened 267 articles for further evaluation. Data on study design, UPC rate/speciation, UPC risk factors, and UPC outcomes were analyzed and described. Results A total of 22 studies met the inclusion criteria for this study. There was a pooled rate of 27.5% (653/2373) deep UPC specimen positivity and C. acnes represented 76.4% (499/653) of these positive specimens. Inanimate specimen positivity was reported at a pooled rate of 20.1% (29/144) across 3 studies. Male patients were more likely to have a UPC; however, the significance of prior surgery, surgical approach, and type of surgery conflicted across multiple papers. Patient reported outcomes and re-operation rates did not differ between positive UPC and negative UPC patients. The utilization of antibiotics and treatment regimen varied across studies; however, the re-infection rates following surgery did not statistically differ based on the inclusion of antibiotics. Conclusion UPCs are a frequent finding during shoulder surgery and C. acnes represents the highest percentage cultured bacteria. Various preoperative risk factors, surgical techniques, and postoperative treatment regimens did not significantly affect the incidence of UPCs as well as the clinical outcomes for UPC vs. non-UPC patients. A standardized protocol for treatment and follow-up would decrease physician uncertainty when faced with a UPC from shoulder surgery. Given the results of this review, shoulder surgeons can consider not drastically altering the postoperative clinical course in the setting of UPC with no other evidence of PJI.
Article
Introduction: Home chlorhexidine washes prior to shoulder surgery are commonly used in an attempt to reduce the skin bacterial load. However, recent studies have suggested that this agent is relatively ineffective against Cutibacterium acne. Benzoyl peroxide soap is a treatment for acne, but evidence regarding its effectiveness as prophylaxis in shoulder surgery is lacking. Therefore, the objective of this study was to compare the effectiveness of home chlorhexidine washes with benzoyl peroxide soap (BPO) in patients undergoing shoulder arthroplasty surgery in reducing Cutibacterium levels on the skin surface and in the dermis. Methods: Fifty male patients planning to undergo shoulder arthroplasty were consented to be randomized into treatment with 4% chlorhexidine solution (CHG) and 10% benzoyl peroxide soap (BPO) used to wash the operative shoulder the night prior and morning of surgery. Skin swabs prior to incision and dermal wound swabs after incision were obtained, and the bacterial load was reported in a semiquantitative manner as the Specimen Cutibacterium Value (SpCuV). The two groups were compared with regards to the percent positivity of the skin surface and incised dermal edge as well as the bacterial load at each site. Results: Skin surface swabs were positive in 100% of patients using CHG and 100% of patients using BPO soap. The Cutibacterium load (SpCuV) on the skin surface was similar between the two groups (CHG 1.6 ± 1.1 vs. BPO 1.5 ± 1.4, p = 0.681). The percentages of dermal cultures that were positive were not significantly different between the two groups (CHG 61% vs BPO 46%, p = 0.369). The Cutibacterium load (SpCuV) on the incised dermal edge was similar between the two groups (CHG 0.8 ± 1.0 vs. BPO 0.8 ± 1.4, p = 0.991). Discussion: Neither BPO soap nor chlorhexidine washes prior to shoulder surgery were effective in eliminating Cutibacterium from the skin surface or the incised dermal edge. Further study of means of reducing the Cutibacterium load of the skin at the time of shoulder arthroplasty is warranted.
Article
Background The skin of healthy shoulders is known to harbor multiple different subtypes of Cutibacterium (formerly Propionibacterium) acnes at the same time. C acnes can often be isolated from deep tissue and explant samples obtained during revision of a failed shoulder arthroplasty, presumably because the shoulder was inoculated with organisms from the patient's skin at the time of the index arthroplasty. It is possible that specific subtypes or distributions of subtypes may be associated with an increased pathogenic potential and that the skin of patients undergoing revision arthroplasty contains different distributions of the subtypes than in patients undergoing primary arthroplasty. We analyzed the subtype distribution of Cutibacterium from the skin of shoulders undergoing revision arthroplasty vs. primary arthroplasty. Methods Preoperative skin swabs were collected from 25 patients who underwent primary shoulder arthroplasty and 27 patients who underwent revision shoulder arthroplasty. The results of semiquantitative cultures of the skin and deep tissues were reported as specimen Cutibacterium values, and scores from all deep tissue samples were added to report the total shoulder Cutibacterium score. Single-locus sequence typing (SLST) of C acnes from the skin swabs was used to determine the subtype distribution for each patient. The percentage of each subtype for each patient was averaged in patients undergoing revision arthroplasty and then compared with that in patients undergoing primary arthroplasty. Results The C acnes subtype distribution on the skin of revision arthroplasty patients was different from that of primary shoulder arthroplasty patients, with a significantly higher percentage of SLST subtype A (36.9% vs. 16.0%, P = .0018). The distribution of SLST subtypes was similar between revision arthroplasty patients with strongly positive culture findings vs. those with weakly positive or negative culture findings. Conclusions Significant differences in the skin Cutibacterium subtype distributions were found between shoulders undergoing revision shoulder arthroplasty and those undergoing primary shoulder arthroplasty. Future studies are needed to determine whether certain Cutibacterium subtype distributions are associated with an increased risk of arthroplasty revision.
Article
Introduction: The rationale for discarding the skin knife blade and replacing it with another blade for deeper dissection is to prevent bacteria that may be present on the skin from being carried into the deeper layers of the wound. This practice is very controversial because numerous, yet limited, studies exist that support and refute the findings. The purpose of this study was to directly compare the rate of contamination of a skin knife blade with a control blade. Methods: We took the surface samples using Replicate Organism Detection and Counting plates of 344 knife blades immediately after making skin incision during the following four types of orthopaedic cases: total hip arthroplasty, total knee arthroplasty, lumbar spine surgery, and cervical spine surgery. At the same time, we sampled 344 control blades. The comparison of positives skin versus control, overall and within each subgroup was done using a bivariate two-sample z-test for the equality of proportions. Results: Overall, 35 (5.1%) of the 688 specimens had a positive result. No difference was noted in the rate of positive cultures for the 344 skin blades 4.9% and the 344 control blades 5.2%. No differences were observed in the rate of positive specimens for skin blades (7.4%, 3.4%, 7.7%, and 3.9%) and control blades (2.5%, 4.1%, 7.7%, and 9.2%) for total hip arthroplasty, total knee arthroplasty, C spine, and L spine, respectively. No differences were observed regarding skin prep, room number, case order, room turnover time, or in-room to incision time. Staphylococus species was the predominant bacteria identified. Conclusion: We found no evidence to support the theoretical advantage of changing the knife blade after making skin incision to avoid contamination. Contamination rates were the same for both the skin and control blades overall and for all subgroup analysis.
Article
Background Periprosthetic Joint Infections (PJI) is a catastrophic complication after joint arthroplasty. Infections in shoulder joints are usually caused by Cutibacterium acnes and coagulase-negative Staphylococci (CNS), which are difficult to diagnose because of their low virulence. Most of the systematic reviews on PSI diagnosis are narrative descriptions; there are few comprehensive and systematic summaries. The purpose of this systematic review and meta-analysis is to summarize all diagnostic studies on PSI, evaluate the accuracy of standard diagnostic methods, and attempt to find the thresholds of serum test, tissue culture, and histopathology of PSI. Methods We systematically searched the MEDLINE, EMBASE, and Cochrane databases (from the inception of each database until January 1, 2020). QUADAS-2 was used to evaluate the bias risk and clinical applicability of each included study. We used the bivariate meta-analysis framework to pool the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), area under the SROC curve (AUC) and its 95% confidence interval (95% CI). Results The search identified 30 articles reporting 27 diagnostic methods in 5 categories (Serum test, Synovial test, Tissue culture, Histopathology, and Imaging). Meta-analysis was performed on the inspection items of more than four studies. The AUCs of serum CRP, serum ESR, serum WBC count, tissue culture, and histopathology were 0.69, 0.28, 0.75, 0.94, and 0.94, respectively. Conclusion Our data suggest that tissue culture is the most accurate diagnostic method for PSI, and using a single tissue positive as a culture-positive seems to improve the diagnostic accuracy compared with using two tissue positives. All serum tests had low diagnostic value, and when using the cut-off recommend by the 2018 ICM, future studies may focus on whether diagnostic accuracy can be improved by lowering the diagnostic threshold. Level of evidence Systematic Review
Article
Background This review aims to establish current knowledge of the shoulder skin microbiome and how to manage the bacteria that reside within it. Methods A review was undertaken of the current literature through OvidSP. All abstracts were reviewed by three independent researchers. Results Thirty-five studies met the inclusion criteria. With forward referencing an additional 14 were included. None commented on organisms specific to the shoulder microbiome other than Cutibacterium acnes. Therefore, this review is focussed on the current knowledge of C. acnes. Discussion C. acnes is a skin commensal within the pilo-sebaceous glands reported to be the primary pathogen in up to 86% of shoulder joint infections. Pre-operative culture of unprepared skin can be indicative of underlying joint infection in shoulder arthroplasty revision. Intra-articular biopsies may have a high false positive due to skin contamination. Correlating the number of positive samples and certain associated signs can give a greater than 90% probability of a true infection. Standard surgical skin preparation, peri-surgical intravenous antibiotics and oral pre-operative antibiotics do not reduce bacterial load within the skin. However, topical benzoyl peroxide and clindamycin have both demonstrated significantly reduced bacteria load. Phylogenetically there are six main types. Patients may have more than one phenotype present during infection.
Article
Two predominant prophylactic home skin-disinfection regimens exist in shoulder surgery, benzoyl peroxide and chlorhexidine. Of these 2 regimens, benzoyl peroxide gel is more effective than chlorhexidine in reducing the rate of positive Cutibacterium cultures on the skin surface. At present, there are no studies that assess the impact of these home prophylactic measures on clinical infection rates.
Article
Introduction There is no current standard by which culture specimens from revision shoulder arthroplasty should be handled, processed, cultured, and reported. Due to the relatively low numbers of cases multicenter study may provide information to form consensus recommendations. However, assimilation of multicenter data requires comparable methodologies. The objective of this study was to document and evaluate the extent of variability between surgeons and institutions. Methods An 11-question survey was sent to 20 shoulder surgeons as part of the American Shoulder and Elbow Society (ASES) Periprosthetic Joint Infection (PJI) Multicenter Workgroup. Questions addressed how samples are handled in the operating room by surgeons, processing of tissue samples and explants by laboratories, number of media, culture incubation durations, and culture reporting. Results Common practices regarding specimen handling and processing were identified including prolonged culture incubation times >13 days (94% of participants). However, substantial variation in handling of tissue and explant specimens, number and type of media used, and reporting of results were identified. The majority of surgeons reported using a sterile instrument to harvest each individual tissue specimen (10/17, 59%), more so than using any available instrument (4/17, 24%) or washing and re-using the same instrument (3/17, 18%). Half of the institutions require a time limit by which samples must be processed in the laboratory (8/16, 50%). Nine institutions (9/16, 56%) report cultures in a semi-quantitative manner, while 7 (44%) report cultures in a binary fashion. Five institutions reported having performed a negative control study, and the rate of positive cultures ranged between 0% and 17%. The majority of positive cultures from the negative controls contained Cutibacterium (92%). Discussion Specimen handling, processing, culturing, and reporting varies widely between institutions. Due to the risk of false positives as demonstrated by negative control studies, surgeons should be cognizant of potential sources of contamination at the specimen handling level in the operating room and specimen processing level in the laboratory. Given the challenges in interpretation of positive cultures in revision shoulder arthroplasty, further studies are needed to determine whether assimilation of data across institutions is acceptable or whether a standard culturing methodology across institutions is necessary. Level of Evidence: V
Article
Background Periprosthetic shoulder infection remains a difficult complication to identify and treat. In efforts to improve provide clarity, a subgroup of the Second International Consensus Meeting on Musculoskeletal Infection (ICM) generated over 70 recommendations. To understand the current treatment practices and impact of the ICM's work, a survey of shoulder arthroplasty providers was performed. Methods A 22-question survey, consisting of questions based upon the ICM consensus statement and the clinical experience of these authors, was distributed to all active members of the American Shoulder and Elbow Surgeons. Questions regarded the work-up, diagnosis, and treatment of periprosthetic shoulder infection—with specific attention to Cutibacterium acnes. Results One hundred fifty-nine members completed the survey (16%; 159/990) between August 8 and October 18, 2019. Only two-thirds of respondents reported utilizing the definition of periprosthetic shoulder infection proposed by the ICM subgroup. The survey results and associated literature review provided here demonstrate continued discordance regarding the diagnostic work-up and treatment of periprosthetic shoulder infection. Conclusion It is imperative that the shoulder arthroplasty community adopts a uniform definition for periprosthetic shoulder infection as well as a multispecialty team-based approach to improve patient care and better focus future research. Level of Evidence Level IV; Survey Study; Case Series
Article
Hypothesis and background We hypothesized that benzoyl peroxide (BPO) would reduce the presence of Cutibacterium acnes on the skin of the shoulder by 50% compared with placebo. Infections after shoulder surgery are most commonly caused by C acnes. Current prophylactic methods do not effectively reduce the bacterial load of this bacterium. However, it seems that BPO may reduce C acnes on the skin of the shoulder. Therefore, this study aimed to investigate the effect of BPO on the presence of C acnes on the shoulder skin. Methods A double-blinded, randomized, placebo-controlled trial was performed including healthy participants aged between 40 and 80 years. Thirty participants with C acnes on the shoulder skin according to baseline skin swabs were randomized into the BPO or placebo group. After gel application 5 times, skin swabs were taken to determine the presence of C acnes. Results Forty-two participants were screened for the presence of C acnes to include 30 participants with the bacterium. Participants with C acnes at baseline were 7.4 years younger than participants without C acnes (P = .015). One participant in the placebo group dropped out before application because of fear of adverse events. After application, C acnes remained present in 3 of 15 participants (20.0%) in the BPO group and in 10 of 14 participants (71.4%) in the placebo group, resulting in a 51.4% reduction in the presence of C acnes. Conclusion Applying BPO 5 times on the shoulder skin effectively reduces C acnes. Consequently, BPO may reduce the risk of postoperative infections.
Article
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Background: Deep infection after shoulder arthroplasty is a diagnostic and therapeutic challenge. The current literature on this topic is from single institutions or Medicare samples, lacking generalizability to the larger shoulder arthroplasty population. Questions/purposes: We sought to identify (1) patient-specific risk factors for deep infection, and (2) the pathogen profile after primary shoulder arthroplasty in a large integrated healthcare system. Methods: A retrospective cohort study was conducted. Of 4528 patients identified, 320 had died and 302 were lost to followup. The remaining 3906 patients had a mean followup of 2.7 years (1 day-7 years). The study endpoint was the diagnosis of deep infection, which was defined as revision surgery for infection supported clinically by more than one of the following criteria: purulent drainage from the deep incision, fever, localized pain or tenderness, a positive deep culture, and/or a diagnosis of deep infection made by the operating surgeon based on intraoperative findings. Risk factors evaluated included age, sex, race, BMI, diabetes status, American Society for Anesthesiologists (ASA) score, traumatic versus elective procedure, and type of surgical implant. For patients with deep infections, we reviewed the surgical notes and microbiology records for the pathogen profile. Multivariable Cox regression models were used to evaluate the association of risk factors and deep infection. Adjusted hazard ratios and 95% CI are presented. Results: With every 1-year increase in age, a 5% (95% CI, 2%-8%) lower risk of infection was observed. Male patients had a risk of infection of 2.59 times (95% CI, 1.27-5.31) greater than female patients. Patients undergoing primary reverse total shoulder arthroplasty had a 6.11 times (95% CI, 2.65-14.07) greater risk of infection compared with patients having primary unconstrained total shoulder arthroplasty. Patients having traumatic arthroplasties were 2.98 times (95% CI, 1.15-7.74) more likely to have an infection develop than patients having elective arthroplasties. BMI, race, ASA score, and diabetes status were not associated with infection risk (all p > 0.05). Propionibacterium acnes was the most commonly cultured organism, accounting for 31% of isolates. Conclusions: Younger, male patients are at greater risk for deep infection after primary shoulder arthroplasty. Reverse total shoulder arthroplasty and traumatic shoulder arthroplasties also carry a greater risk for infection. Propionibacterium acnes was the most prevalent pathogen causing infection in our primary shoulder arthroplasty population. Level of evidence: Level II, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.
Article
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A prospective study was performed to establish criteria for the microbiological diagnosis of prosthetic joint infection at elective revision arthroplasty. Patients were treated in a multidisciplinary unit dedicated to the management and study of musculoskeletal infection. Standard multiple samples of periprosthetic tissue were obtained at surgery, Gram stained, and cultured by direct and enrichment methods. With reference to histology as the criterion standard, sensitivities, specificities, and likelihood ratios (LRs) were calculated by using different cutoffs for the diagnosis of infection. We performed revisions on 334 patients over a 17-month period, of whom 297 were evaluable. The remaining 37 were excluded because histology results were unavailable or could not be interpreted due to underlying inflammatory joint disease. There were 41 infections, with only 65% of all samples sent from infected patients being culture positive, suggesting low numbers of bacteria in the samples taken. The isolation of an indistinguishable microorganism from three or more independent specimens was highly predictive of infection (sensitivity, 65%; specificity, 99.6%; LR, 168.6), while Gram staining was less useful (sensitivity, 12%; specificity, 98%; LR, 10). A simple mathematical model was developed to predict the performance of the diagnostic test. We recommend that five or six specimens be sent, that the cutoff for a definite diagnosis of infection be three or more operative specimens that yield an indistinguishable organism, and that because of its low level of sensitivity, Gram staining should be abandoned as a diagnostic tool at elective revision arthroplasty.
Article
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Deep infection of the shoulder following rotator cuff repair is uncommon. There are few reports in the literature regarding the management of such infections. We retrospectively reviewed the charts of thirteen patients and recorded the demographic data, clinical and laboratory findings, risk factors, bacteriological findings, and results of surgical management. The average age of the patients was 63.7 years. The interval between the rotator cuff repair and the referral because of infection averaged 9.7 months. An average of 2.4 procedures were performed prior to referral because of infection, and an average of 2.1 procedures were performed at our institution. All patients had pain on presentation, and most had a restricted range of motion. Most patients were afebrile and did not have an elevated white blood-cell count but did have an elevated erythrocyte sedimentation rate. The most common organisms were Staphylococcus epidermidis, Staphylococcus aureus, and Propionibacterium species. At an average of 3.1 years, all patients were free of infection. Using the Simple Shoulder Test, eight patients stated that the shoulder was comfortable with the arm at rest by the side, they could sleep comfortably, and they were able to perform activities below shoulder level. However, most patients had poor overhead function. Extensive soft-tissue loss or destruction is associated with a worse prognosis. Extensive débridement, often combined with a muscle transfer, and administration of the appropriate antibiotics controlled the infection, although most patients were left with a substantial deficit in overhead function of the shoulder.
Article
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Acne vulgaris is an extremely common disorder affecting many adolescents and adults throughout their lifetimes. The pathogenesis of acne is multifactorial and is thought to involve excess sebum, follicular hyperkeratinization, bacterial colonization, and inflammation. Many therapeutic options exist for treating acne, including topical benzoyl peroxide, topical and oral antibiotics, topical and oral retinoids, and oral contraceptives. Oral antibiotics have been a mainstay in the treatment of acne for decades and function by exerting an antibacterial effect by reducing the follicular colonization of Propionibacterium acnes. Systemic antibiotics also have anti-inflammatory and immunomodulatory properties. This article reviews the English language literature on the efficacy of various systemic antibiotics for treating acne vulgaris, including second-line and less historically used medications. We discuss the tetracyclines, including subantimicrobial dose doxycycline, macrolides (notably azithromycin), trimethoprim-sulfamethoxazole, cephalosporins, and fluoroquinolones as treatment options for acne vulgaris.
Article
Propionibacterium acnes has arisen as the most common microorganism identified at the time of revision shoulder arthroplasty. There is limited evidence to suggest how frequently false-positive cultures occur. The purpose of this prospective controlled study was to evaluate culture growth from specimens obtained during open shoulder surgery. Patients undergoing an open deltopectoral approach to the shoulder were prospectively enrolled. Patients with a history of shoulder surgery or any concern for active or previous shoulder infection were excluded. Three pericapsular soft-tissue samples were taken from the shoulder for bacterial culture and were incubated for fourteen days. A sterile sponge was also analyzed in parallel with the tissue cultures. In addition, similar cultures were obtained from patients who had undergone previous shoulder surgery. Overall, 20.5% of surgeries (twenty-four of 117) yielded at least one specimen removed for culture that was positive for bacterial growth, and 13.0% of sterile control specimens (seven of fifty-four) had positive culture growth (p = 0.234). P. acnes represented 83.0% of all positive cultures (thirty-nine of forty-seven) at a median incubation time of fourteen days. Among the subjects who had not undergone previous surgery, 17.1% (fourteen of eighty-two) had at least one positive P. acnes culture. Male sex was univariably associated with a greater likelihood of bacterial growth (p < 0.01), and patients who had not undergone previous surgery and had received two or more preoperative corticosteroid injections had a higher likelihood of bacterial growth (p = 0.047). The clinical importance of positive P. acnes cultures from specimens obtained from open shoulder surgery remains uncertain. Male sex and preoperative corticosteroid injections were associated with a higher likelihood of bacterial growth on culture and are risk factors that merit further investigation. Previously reported incidences of positive P. acnes culture results from specimens from primary and revision shoulder arthroplasty may be overestimated because of a substantial level of culture contamination. P. acnes is isolated via culture at a substantial rate from shoulders undergoing a deltopectoral approach. The clinical importance of culture growth by this low-virulence organism still remains uncertain. Further study is necessary to more specifically characterize culture growth by P. acnes as an infection, commensal presence, or contaminant. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.
Article
Propionibacterium acnes is a recognized pathogen in postoperative shoulder infections. A recent study reported growth of P acnes in 42% of glenohumeral joints in primary shoulder arthroplasty, concluding that P acnes may cause shoulder osteoarthritis. Whether these results reflect true bacterial infection or specimen contamination is unclear. Our prospective study aimed to determine the rate of P acnes infection in arthritic shoulders using a strict specimen collection technique. We used modified Oxford protocol to collect tissue specimens from the glenohumeral joint of 32 consecutive patients undergoing primary shoulder arthroplasty. Specimens were cultured specifically for P acnes. Diagnosis of P acnes infection required 2 or more positive cultures and histopathology compatible with infection. Three of 32 patients had a positive culture for P acnes. Overall, 3.125% of specimens grew P acnes without histologic evidence of infection. There were no patients with P acnes infection. The difference in culture rates between patients with idiopathic osteoarthritis and those with a predisposing cause for osteoarthritis was not significant. We found a low rate of positive cultures for P acnes, but no P acnes infection and no difference between types of osteoarthritis. These results do not support a cause-and-effect relationship between P acnes and osteoarthritis. The differing results from previous studies are likely explained by our strict specimen collection technique, reflecting different rates of contamination rather than infection. That P acnes contamination occurs in primary shoulder arthroplasty is concerning. Further studies are needed to assess the rates of contamination in shoulder surgery, its clinical effect, and to determine optimal antibiotic prophylaxis. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.
Article
Propionibacterium acnes has been grown on culture in half of the reported cases of chronic infection associated with shoulder arthroplasty. The presence of this organism can be overlooked because its subtle presentation may not suggest the need for culture or because, in contrast to many orthopaedic infections, multiple tissue samples and weeks of culture incubation are often necessary to recover this organism. Surgical decisions regarding implant revision and antibiotic therapy must be made before the results of intraoperative cultures are known. In the present study, we sought clinically relevant prognostic evidence that could help to guide treatment decisions. We statistically correlated preoperative and intraoperative observations on 193 shoulder arthroplasty revisions that were performed because of pain, loosening, or stiffness with the results of a Propionibacterium acnes-specific culture protocol. Regression models were used to identify factors predictive of a positive culture for Propionibacterium acnes. One hundred and eight of the 193 revision arthroplasties were associated with positive cultures; 70% of the positive cultures demonstrated growth of Propionibacterium acnes. The rate of positive cultures per shoulder increased with the number of culture specimens obtained from each shoulder. Fifty-five percent of the positive cultures required observation for more than one week. Male sex, humeral osteolysis, and cloudy fluid were each associated with significant increases of ≥600% in the likelihood of obtaining a positive Propionibacterium acnes culture. Humeral loosening, glenoid wear, and membrane formation were associated with significant increases of >300% in the likelihood of obtaining a positive Propionibacterium acnes culture. Preoperative and intraoperative factors can be used to help to predict the risk of a positive culture for Propionibacterium acnes. This evidence is clinically relevant to decisions regarding prosthesis removal or retention and the need for immediate antibiotic therapy at the time of revision shoulder arthroplasty before the culture results become available. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.
Article
Background: Propionibacterium acnes is a common pathogen in infections after shoulder surgery. Recent reports found positive P acnes cultures in a high percentage of patients who had revision shoulder arthroplasty for "aseptic loosening" without any overt signs of infection. Isolation of P acnes is difficult, and by use of conventional microbiological protocols of 48-hour incubation, a considerable proportion of patients with possible P acnes infection may remain unidentified. We recently noted P acnes in shoulder joint cultures in patients undergoing primary shoulder replacement for glenohumeral arthropathy without any signs of infection. Methods: We collected aspirates and biopsy specimens from 55 consecutive patients with arthritic shoulders undergoing primary joint replacement and examined them for the presence of P acnes. Special measures were taken to ensure that the specimens were carefully taken from within the joint to reduce the risk of contamination to minimal. Results: In 23 of 55 consecutive patients (41.8%) undergoing primary shoulder joint replacement, P acnes was found in the joint fluid and tissues taken before the insertion of the implants. All these patients were treated early postoperatively with pathogen-directed specific dual oral antibiotic treatment for 4 weeks. In none have any signs of infection developed. Discussion and conclusion: This finding of a high incidence of P acnes in joints before arthroplasty may suggest a role of P acnes in the pathogenesis of glenohumeral arthropathy. In addition, it raises the question of whether development of painful joint replacement later on and presumed aseptic loosening do, in fact, comprise an unrecognized low-grade infection that has been present since before the index operation.
Article
To examine the rates and predictors of deep periprosthetic infections after primary total shoulder arthroplasty (TSA). We used prospectively collected data on all primary TSA patients from 1976-2008 at Mayo Clinic Medical Center. We estimated survival free of deep periprosthetic infections after primary TSA using Kaplan-Meier survival. Univariate and multivariable Cox regression was used to assess the association of patient-related factors (age, gender, body mass index), comorbidity (Deyo-Charlson index), American Society of Anesthesiologists class, implant fixation, and underlying diagnosis with risk of infection. A total of 2,207 patients, with a mean age of 65 years (SD, 12 years), 53% of whom were women, underwent 2,588 primary TSAs. Mean follow-up was 7 years (SD, 6 years), and the mean body mass index was 30 kg/m(2) (SD, 6 kg/m(2)). The American Society of Anesthesiologists class was 1 or 2 in 61% of cases. Thirty-two confirmed deep periprosthetic infections occurred during follow-up. In earlier years, Staphylococcus predominated; in recent years, Propionibacterium acnes was almost as common. The 5-, 10-, and 20-year prosthetic infection-free rates were 99.3% (95% confidence interval [CI], 98.9-99.6), 98.5% (95% CI, 97.8-99.1), and 97.2% (95% CI, 96.0-98.4), respectively. On multivariable analysis, a male patient had a significantly higher risk of deep periprosthetic infection (hazard ratio, 2.67 [95% CI, 1.22-5.87]; P = .01) and older age was associated with lower risk (hazard ratio, 0.97 [95% CI, 0.95-1.00] per year; P = .05). The periprosthetic infection rate was low at 20-year follow-up. Male gender and younger age were significant risk factors for deep periprosthetic infections after TSA. Future studies should investigate whether differences in bone morphology, medical comorbidity, or other factors are underlying these associations.
Article
Deep infection following shoulder surgery is a rare but devastating problem. The use of an effective skin-preparation solution may be an important step in preventing infection. The purposes of the present study were to examine the native bacteria around the shoulder and to determine the efficacy of three different surgical skin-preparation solutions on the eradication of bacteria from the shoulder. A prospective study was undertaken to evaluate 150 consecutive patients undergoing shoulder surgery at one institution. Each shoulder was prepared with one of three randomly selected solutions: ChloraPrep (2% chlorhexidine gluconate and 70% isopropyl alcohol), DuraPrep (0.7% iodophor and 74% isopropyl alcohol), or povidone-iodine scrub and paint (0.75% iodine scrub and 1.0% iodine paint). Aerobic and anaerobic cultures were obtained prior to skin preparation for the first twenty patients, to determine the native bacteria around the shoulder, and following skin preparation for all patients. Coagulase-negative Staphylococcus and Propionibacterium acnes were the most commonly isolated organisms prior to skin preparation. The overall rate of positive cultures was 31% in the povidone-iodine group, 19% in the DuraPrep group, and 7% in the ChloraPrep group. The positive culture rate for the ChloraPrep group was lower than that for the povidone-iodine group (p < 0.0001) and the DuraPrep group (p = 0.01). ChloraPrep and DuraPrep were more effective than povidone-iodine in eliminating coagulase-negative Staphylococcus from the shoulder region (p < 0.001 for both). No significant difference was detected among the agents in their ability to eliminate Propionibacterium acnes from the shoulder region. No infections occurred in any of the patients treated in this study at a minimum of ten months of follow-up. ChloraPrep is more effective than DuraPrep and povidone-iodine at eliminating overall bacteria from the shoulder region. Both ChloraPrep and DuraPrep are more effective than povidone-iodine at eliminating coagulase-negative Staphylococcus from the shoulder.
Article
Propionibacterium acnes (P. acnes) is frequently cultured in patients with wound infections after shoulder surgery. The purpose of this study was to characterize the colonization of various anatomic locations with P. acnes in order to explain this clinical observation. Culture samples were collected from the skin overlying the shoulder, hip, and knee of 20 subjects (10 male, 10 female). Semi-quantitative cultures of P. acnes and Staphylococcus species were performed to define bacterial prevalence and burden at each site. The participants completed a questionnaire that assessed skin health, hygiene, and co-morbid medical conditions. Physical examination was performed to define local skin characteristics. Anterior and posterior acromial sites had a greater prevalence of P. acnes than the hip (anterior p=0.018; posterior p= 0.038) and knee (anterior p=0.0014; posterior p= 0.035) sites. The axilla had a greater prevalence of P. acnes than the knee (p=0.008). Males had a greater prevalence of P. acnes than females at the anterior (p=0.007) and posterior acromion sites (p=0.025). The burden of P. acnes at the anterior acromion (p=0.024), posterior acromion (p=0.035), and axilla (p=0.03) was greater than the mean burden at the hip. The burden of P. acnes at the anterior acromion (p=0.004), posterior acromion (p=0.007), and axilla (p=0.008) was greater than the mean burden at the knee. Males had a greater burden of P. acnes than females at the acromial sites (anterior p=0.0049; posterior p=0.0131). Propionibacterium acnes colonizes the shoulder at increased rates compared to the knee and hip, and men have a higher bacterial burden than females. These findings are consistent with clinical observations of postoperative shoulder infections. Basic science study.
Article
Between 1972 and 1994, 2279 patients underwent primary shoulder arthroplasty (2512 shoulders) and 194 patients underwent revision shoulder arthroplasty (222 shoulders) at the authors' institution. Of these, 18 patients with primary shoulder arthroplasties (19 shoulders) and seven patients with revision shoulder arthroplasties (seven shoulders) were diagnosed with deep periprosthetic infection. Additionally, during this period, seven patients (seven shoulders) with primary shoulder arthroplasties and one patient (one shoulder) with a previously revised shoulder arthroplasty were referred to the authors' institution for treatment of deep periprosthetic infection. Two patients (two shoulders) were excluded because of incomplete medical records and with component removal performed elsewhere. The average time from arthroplasty to the diagnosis of infection was 3.5 years (range, 0-14.8 years). The patients were divided into four groups on the basis of treatment. Group I comprised 20 patients (21 shoulders) who underwent resection arthroplasty. Six of the 21 shoulders had additional episodes of infection. Group II comprised six patients (six shoulders) who underwent debridement and prosthetic retention. Three of the six shoulders failed this treatment with subsequent reinfection and underwent a resection arthroplasty. Group III comprised two patients (two shoulders) who had removal of the prosthesis, debridement, and immediate reimplantation. One patient underwent resection arthroplasty 9 months after direct exchange because of reinfection. Group IV comprised three patients (three shoulders) who had removal of the prosthesis, debridement, and delayed reimplantation. Reinfection has not occurred in any of these patients. At final followup, patients with a prosthesis in situ had better pain relief and shoulder function than patients treated with resection arthroplasty. Delayed reimplantation may offer the best hope for pain relief, eradication of infection, and maintenance of shoulder function.
Article
A consecutive case series from 2 institutions of patients with postoperative wound infections after mini-open rotator cuff repair was reviewed. Between 1991 and 2000, 360 patients underwent mini-open rotator cuff repair after arthroscopic subacromial decompression. Seven patients had postoperative infection develop (1.9%). All patients were men, with a mean age of 55 years (range, 40-64 years). Treatment included serial irrigation and debridement, long-term intravenous antibiotics, and revision rotator cuff repair. Mean follow-up after definitive treatment was 32 months (range, 12-57 months). Propionibacter acnes was present in 6 of 7 patients (86%) with infections. The initial rotator cuff repair was disrupted in 4 shoulders and intact in 3. A revision rotator cuff repair was performed at the final irrigation and debridement in all 4 shoulders. Results were 100% satisfactory. The mean American Shoulder and Elbow Surgeons pain score improved from 7 (range, 6-9) preoperatively to 1 (range, 0-2). The mean final score was 95. Because these infections were noted to occur only in arthroscopically assisted rotator cuff repairs, a second preparation and draping were introduced as routine protocol. No postoperative infections have occurred in the ensuing 200 mini-open rotator cuff repairs.
Article
Currently, there is little information available concerning the outcome of patients with infection after rotator cuff repair. The purpose of this study was to review retrospectively the incidence, clinical presentation, bacteriology, treatment, and outcomes of patients with rotator cuff repair complicated by deep infection. Between 1975 and 2003, 39 cases of deep infection after rotator cuff repair were identified in 38 patients. At a final follow-up of 8.2 years (range, 30 months to 19.8 years), 7 patients had died and 2 had been lost to follow-up, leaving 29 for outcome evaluation. Propionibacterium acnes was the most common organism isolated, infecting 20 of 39 cases (51%). At final follow-up, mean active elevation was 120 degrees and mean external rotation was 45 degrees . The American Shoulder and Elbow Surgeons score averaged 67 points (range, 5-100 points), and the Simple Shoulder Test score averaged 7.3 points (range, 1-12 points). The results were excellent in 7 shoulders, satisfactory in 9, and unsatisfactory in 11. The data from this study suggest that the eradication of deep infection after rotator cuff repair is possible; however, substantial functional limitations are not unusual. In addition, the treating surgeon should be aware of the high incidence of Propionibacterium and the importance of allowing a minimum of 7 days of culture to identify this organism.
Article
Prosthetic joint infection (PJI) can present a diagnostic challenge, especially with slow-growing and poorly virulent bacteria. To describe the epidemiological, clinical and biological characteristics of Propionibacterium acnes PJI, their treatments and outcomes and compare 2 clinical pictures (according to the time PJI symptoms appeared after the index operation: < or = 2 years, > 2 years). We conducted a cohort study on P. acnes PJI. Diagnosis was based on > or = 2 positive cultures of intraoperative specimens taken during revision arthroplasties for infection or presumed aseptic loosening. Fifty patients with prosthetic hip (34), knee (10) or shoulder (6) infections were included and analyzed according to their symptom-free interval: < or = 2 years for 35 and > 2 years for 15 (mean interval: 11+/-6 years). The numbers of previous prostheses (p=0.04) were higher for the shorter-interval group, which had more frequent signs of infection (p=0.004). These findings suggest infection in most of the patients whose PJI symptoms appeared: < or = 2 years after the index operation, and colonization in the majority of those whose symptoms appeared > 2 years after index surgery. Treatment combining exchange arthroplasty with prolonged intravenous antibiotics was successful for 92% of the patients. P. acnes can cause different types of PJI: late chronic infections, colonization of loosened prostheses and, exceptionally, acute postoperative infections.
Article
The purpose of this study, which involved 276 patients, was to report the importance of Propionibacterium acnes in shoulder infections. The proportion of patients with shoulder infection who had infection due to P. acnes was significantly greater than the proportion of patients with lower limb infection who had infection due to P. acnes (9 of 16 patients vs. 1 of 233 patients; P<.001 ). This bacterium requires a prolonged incubation period and should not be considered to be a contaminant.