Preoperative Doxycycline Does Not Reduce Propionibacterium acnes in Shoulder Arthroplasty

Hydrogen Peroxide May Reduce the Risk for Revision Surgery and Infection in Primary Shoulder Arthroplasty: Two-year Follow-up From a Prospective, Blinded, Controlled Trial

BACKGROUND

The purpose of this study was to determine whether the addition of hydrogen peroxide to the preoperative skin preparation for primary total shoulder arthroplasty is associated with a difference in patient-reported outcomes, risk for postoperative infection, and risk for revision surgery at a minimum of 2-year follow-up.

METHODS

This was a prospective, blinded, and controlled trial, which included a consecutive series of patients undergoing primary shoulder arthroplasty. The control group underwent standard sterile skin preparation using ethyl alcohol and ChloraPrep applicators, and the peroxide group had the same preparation with the addition of hydrogen peroxide between the alcohol and ChloraPrep applications. We then compared patient-reported outcome scores (American Shoulder and Elbow Surgeons Shoulder Score [ASES], simple shoulder test [SST], visual analog scale [VAS]), infections, and revision surgeries between the two groups at 2-year follow-up.

RESULTS

Of the 61 patients included in the original study, 52 of 58 (85%) living patients agreed to participate in this study. No preoperative differences were observed between groups. No difference was observed in ASES, SST, or VAS scores at 2 years. More revision surgeries were done in the control group (7 versus 2, P = 0.268) and Cutibacterium acnes infections (2 versus 0, P = 0.168).

CONCLUSION

The addition of hydrogen peroxide to the preoperative skin preparation before primary shoulder arthroplasty is safe, and additional research is warranted to investigate whether it may decrease the risk for revision surgery and postoperative C acnes infection.

LEVEL OF EVIDENCE

III.

Antimicrobial effects of blue light therapy against cutibacterium acnes: optimal dosing and impact of serial treatments

Background

Blue light therapy (BLT) is a Food and Drug Administration cleared modality used in dermatology as an effective treatment of acne. The primary purpose of this study is to determine if there are dose-dependent antimicrobial effects of BLT against Cutibacterium acnes (C. acnes).

Methods

A known strain of C. acnes was grown on chocolate agar in a controlled laboratory environment under anaerobic conditions for 1 week. After 1 week, 2-3 colonies of C. acnes were isolated and transferred to broth medium to incubate for 2 or 7 days. Broth vials (treatment arm) then underwent 1 of 6 different blue light dosing treatment regimens and a duplicate broth vial served as a control left open to the same environment. The BLT regimens were a single treatment of 25 J/cm2, 50 J/cm2, 75 J/cm2, 100 J/cm2, 2 serial treatments of 50 J/cm2 separated by 24 hours, or 2 serial treatments of 75 J/cm2 separated by 24 hours. The Omnilux Blue device (415 nm wavelength) was used for all BLT treatments and delivered, on average, 1.68 ± 0.004 J/min. Following treatment, the control and treatment broth samples were plated on chocolate agar and allowed to grow for 7 days. After 7 days, plates were counted and colony forming units (CFUs) were calculated. Six trials were completed for each BLT dosing regimen based on an a priori power analysis of 6 individual 2-sided t-tests. Comparisons in the primary outcome were made via mixed-effects analysis of variance with replicate as a random effect.

Results

All BLT treatment regimens resulted in significantly fewer CFUs than their aggregate control plate CFUs (P < .05 for all). Furthermore, in 2-way comparison of CFUs between BLT treatment groups, a single treatment of 75 J/cm2 did lead to significantly less growth than 25 J/cm2 (P = .017) and 50 J/cm2 (P = .017). There were no improved antimicrobial effects with serial treatments when comparing 2 doses of 50 J/cm2 with a single dose of 100J/cm2, nor were 2 doses of 75 J/cm2 more efficacious than 100 J/cm2. Using the Omnilux Blue device, it took 44.8 minutes to deliver a 75 J/cm2 dose.

Conclusion

BLT is an effective antimicrobial agent against this single virulent strain of C. acnes. Treatment dosing of 75 J/cm2 was identified to be the most effective dose per unit time. Serial treatments did not lead to superior antimicrobial effects over a single, high-dose treatment.

Doxycycline Prophylaxis for Skin and Soft Tissue Infections in Naval Special Warfare Trainees, United States1

In 2015, several severe cases of skin and soft tissue infection (SSTI) among US Naval Special Warfare trainees prompted the introduction of doxycycline prophylaxis during the highest-risk portion of training, Hell Week. We performed a retrospective analysis of the effect of this intervention on SSTI incidence and resulting hospital admissions during 2013-2020. In total, 3,371 trainees underwent Hell Week training during the study period; 284 SSTIs were diagnosed overall, 29 of which led to hospitalization. After doxycycline prophylaxis was introduced, admission rates for SSTI decreased from 1.37 to 0.64 admissions/100 trainees (p = 0.036). Overall SSTI rates remained stable at 7.42 to 8.86 SSTIs/100 trainees (p = 0.185). Hospitalization rates per diagnosed SSTI decreased from 18.4% to 7.2% (p = 0.009). Average length of hospitalization decreased from 9.01 days to 4.33 days (p = 0.034). Doxycycline prophylaxis was associated with decreased frequency and severity of hospitalization for SSTIs among this population.

Preoperative prophylactic antibiotics administration does not influence culture yield in revision shoulder arthroplasty

BACKGROUND

The importance of administrating prophylactic antibiotics prior to a surgical procedure is well established. Given the difficulty in diagnosing shoulder periprosthetic infections, which are more indolent in nature, some advocate holding prophylactic antibiotics prior to obtaining cultures as there is a concern antibiotics may lead to a false negative culture result. The purpose of this study is to determine whether administration of antibiotics prior to obtaining cultures in revision shoulder arthroplasty influences culture yield.

METHODS

This was a retrospective analysis of revision shoulder arthroplasty cases performed at a single institution between 2015 and 2021. During the study period, each surgeon had a standardized protocol that dictated whether antibiotics were given or held prior to each revision surgery. Each case was categorized into either a Preculture antibiotic group, if antibiotics were administered prior to incision, or a Postculture antibiotic group if antibiotics were administered after incision and obtaining cultures. The International Consensus Meeting (ICM) scoring criteria provided by the Musculoskeletal Infection Society was used to categorize the probability of periprosthetic joint infection for each case. Culture positivity was calculated as the ratio of positive cultures and total number of cultures obtained.

RESULTS

One hundred twenty-four patients met inclusion criteria. There were 48 patients in the Preculture group and 76 patients in the Postculture group. No significant difference in patient demographics or ICM criteria (P = .09) was observed between the 2 groups. With regard to culture positivity, there was no difference between the Preculture antibiotic group and the Postculture antibiotic group (16% vs. 15%, P = .82, confidence interval = 8%-25% vs. 10%-20%, respectively).

CONCLUSION

In the setting of revision shoulder arthroplasty, timing of antibiotic administration did not significantly influence culture yield. This study supports the use of prophylactic antibiotics prior to obtaining cultures in revision shoulder arthroplasty.

The safety and efficiency of benzoyl peroxide for reducing Cutibacterium acnes in the shoulder: An updated systematic review and meta-analysis

Background

Cutibacterium acnes (C. acnes), a common pathogen, contributes significantly to infections in shoulder surgery. Prevention of shoulder infection is crucial to improve postoperative functional recovery and reduce costs. This study aimed to perform a systematic review and meta-analysis to assess the safety and efficacy of 5% benzoyl peroxide (BPO) application in the shoulder to decrease C. acnes.

Methods

Three electronic databases were searched as follows: PubMed, Embase, and the Cochrane Library databases. Data extraction for this study was performed by two independent reviewers, and only level I and level II studies were included. The outcome data sources of individual studies were pooled. The fixed-effect model was used to determine the meta-analysis.

Results

There were five level I studies and five level II studies. The results showed that the 5% BPO group had a lower risk of C. acnes positivity [OR, 0.21 (0.15, 0.30), I2 = 24, p &lt; 0.00001]. The pooled analysis results showed that there was no significant difference in the ability of 5% BPO and 5% BPO + clindamycin to reduce C. acnes. However, the lower rate of adverse events was significantly in favour of the non-BPO group compared with the 5% BPO group.

Conclusion

BPO can decrease C. acnes in the shoulder to prevent infection. However, the combination of BPO and clindamycin does not enhance this effect further.

Level of evidence

II, Systematic review and meta-analysis.

Two-stage shoulder arthroplasty after deep infection of the shoulder caused by arthroplasty, osteosynthesis or other surgical procedures: microbial spectrum, complications and functional outcome after at least 1 year follow-up

PURPOSE

Infection represents probably the most challenging complication in shoulder arthroplasty and all other surgical procedures of the shoulder. A deep infection of the shoulder is often combined with a destruction of the joint and a loss of function. In many cases the arthroplasty is the last resort for these patients to obtain a satisfactory function. The objective of this study was to determine outcome data on microbiota and clinical results of a two-stage shoulder arthroplasty procedure after deep infection of the shoulder.

METHODS

Twenty-six patients with a deep shoulder infection after arthroplasty, osteosynthesis, or rotator-cuff repair were included, while two patients had an empyema without prior surgery. All underwent initial surgical debridement with implantation of an antibiotic-loaded spacer, followed by postoperative systemic antibiotics. The patients obtained definitive shoulder arthroplasty in a second surgery. None of the patients had to undergo more than two surgeries before the arthroplasty. The follow-up analysis including microbiota results, complication rates, and functional outcomes could be determined after at least 1 year in 60% of patients (n = 16).

RESULTS

The most frequently detected microorganisms were S. epidermidis (31%, n = 10) and Cutibacterium acnes (19%, n = 6). In 28% (n = 9) of cases multi-drug resistant bacteria were detected and in 35% (n = 8) of cases more than one microorganism was found. The overall revision rate was 42%, 11 of 26 patients, in the first 8 weeks after arthroplasty. Reasons for revision were joint dislocations in 23% (n = 6), 15% (n = 4) postoperative hematomas, one (4%) re-infection and one (4%) periprosthetic fracture. At follow-up after 19.3 ± 5.5 months postoperatively, a mean abduction of 113.4°, anteversion of 122.8° and external rotation of 14° was found, with an average age and gender-adjusted Constant Score of the affected shoulder of 63. The subjects' pain and impairment in normal life measured by a questionnaire with school grades were significantly reduced (p < 0.05) as compared to prior shoulder arthroplasty.

CONCLUSION

The most relevant bacteria in the study cohort were Staphylococcus subspecies and to a lower extent Cutibacterium acnes. A high number of multi-drug resistant and mixed microbiota spectra were detected, defining a need to adapt therapeutic regimen targeting these microbiotas. The two-stage shoulder arthroplasty after a deep infection resulted in excellent infection control with however high early postoperative rates for joint dislocation (23%) and hematomas (15%). At follow-up a stable joint was achieved with a sufficient functional outcome and satisfying outcome for activities of daily living and pain.

CLINICAL TRIAL

Trial registration number: DRKS00016927, date of registration: 2019/03/19.

Techniques for Decreasing Bacterial Load for Open Shoulder Surgery

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

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

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

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

Perioperative Management in Shoulder Arthroplasty: A Review of Current Practice

Perioperative management for patients undergoing shoulder arthroplasty has evolved significantly over the years to reduce overt complications and improve patient outcomes. The groundwork for perioperative care encompasses initial patient selection and education strategies for achieving successful outcome. Multimodal pain management strategies have advanced patient care with the increased use of new regional/local anesthetics. In addition, complications resulting from blood loss and transfusions have been curtailed with the use of synthetic antifibrinolytic agents. It remains critical for shoulder arthroplasty surgeons to optimize patients during the perioperative period through various modalities to maximize functional progression, outcomes, and patient's satisfaction following shoulder arthroplasty.

Efficacy of antimicrobial washes before shoulder surgery against Cutibacterium: a systematic review and meta-analysis

Background

Cutibacterium acnes is a commensal intradermal microorganism that is commonly isolated at revision shoulder arthroplasty. Standard practice chlorhexidine gluconate (CHG) skin preparation agents have limited effectiveness at eradicating C. acnes in the dermis. Benzoyl peroxide (BPO) has demonstrated effectiveness against C. acnes. This meta-analysis compares the efficacy of at-home shoulder decolonization before surgery using CHG vs. BPO to reduce shoulder C. acnes burden.

Methods

This was a Preferred Reporting Items for Systematic Reviews and Meta-Analyses systematic review. PubMed and MEDLINE databases were searched for studies evaluating the effects of CHG and BPO in reducing C. acnes at the shoulder. Trial results were extracted and pooled using a random effects model, separating data from randomized controlled trials (RCTs) and non-RCTs. Methodologic quality of studies was assessed using the Cochrane Risk of Bias Assessment Tools.

Results

Ten studies (589 patients) were included. RCTs showed that both BPO and CHG led to significant reductions in culture positivity compared with negative controls (risk ratio [RR] with 95% confidence interval [CI] = 0.20 [0.13, 0.30], P < .0001 and 0.46 [0.37, 0.57], P < .0001, respectively). Non-RCT data demonstrated similar results comparing BPO and CHG to the control (RR with 95% CI = 0.34 [0.21, 0.57], P < .0001 and 0.31 [0.20, 0.49], P < .0001, respectively). Comparing BPO and CHG, RCT data showed a significant reduction in culture positivity with BPO (RR with 95% CI = 0.46 [0.27, 0.77], P < .009). Of RCTs, 5 were low and one was of moderate risk of bias. Of non-RCTs, 3 had low risk of bias, whereas one had moderate risk of bias.

Conclusion

This review demonstrated that preoperative CHG and BPO can reduce C. acnes at the shoulder. However, BPO exhibits greater efficacy than CHG, potentially because of the compound's ability to penetrate the dermis. BPO is a simple and economical agent that may reduce joint exposure to C. acnes in shoulder surgery.

The efficacy of topical preparations in reducing the incidence of Cutibacterium acnes at the start and conclusion of total shoulder arthroplasty: a randomized controlled trial

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.

Efficacy of combinational therapy using blue light and benzoyl peroxide in reducing Cutibacterium acnes bioburden at the deltopectoral interval: a randomized controlled trial

BACKGROUND

The purpose of this study was to compare the efficacy of blue light therapy (BLT) and 5% topical benzoyl peroxide (BPO) gel in combination with standard chlorhexidine (CHX) preparation in eradicating Cutibacterium acnes at the deltopectoral interval measured by positive, quantitative culture findings.

METHODS

Adult male volunteers were randomized to 1 of 3 treatment groups: BPO, BLT, and BPO followed by BLT. Contralateral shoulders served as matched controls. Volunteers randomized to BPO applied the gel for a total of 5 treatments. In the BLT group, a single 23-minute treatment was administered at an estimated irradiance of 40 mW/cm² (radiant exposure, 55.2 J/cm²). In the BPO-BLT group, volunteers received both treatments as described earlier. After treatment with either BPO, BLT, or both, a single swab culture was taken from the treatment shoulder. Next, control and treatment shoulders were prepared with CHX, and cultures were taken from each shoulder. Cultures were sent for anaerobic quantitative growth analysis with both polymerase chain reaction and Sanger sequencing confirmation of presumptive C acnes colonies.

RESULTS

This study enrolled 60 male volunteers, 20 per group, with no loss to follow-up. After treatment but prior to CHX administration, all culture samples in the BPO group and BLT group grew C acnes. Prior to CHX, 16 samples (80%) in the BPO-BLT group grew C acnes. On quantitative analysis, the BPO group and BPO-BLT group had significantly less growth of C acnes compared with the BLT group after treatment but prior to CHX (P < .05 for each). Following CHX administration, the BPO and BPO-BLT groups had significantly fewer positive culture findings (odds ratios of 0.03 and 0.29, respectively) and less quantity of growth compared with their control arms (P < .05). This was not seen in the BLT group. For quantitative between-group analysis, no significant synergistic effects were seen with BPO-BLT compared with BPO alone (P = .688). There was no difference in side effects between groups.

CONCLUSION

The combination of topical BPO and CHX was effective at eliminating C acnes in most cases. BLT alone did not demonstrate effective antimicrobial properties against C acnes at the radiant exposure administered in this study. Combining BPO and BLT did not lead to significant synergistic antimicrobial effects. Both BPO and BLT are safe with few, transient side effects reported. More work is needed to determine whether BLT at higher radiant exposures or serial treatment results in bactericidal effects against C acnes in vivo.

Perioperative Management in Reverse Total Shoulder Arthroplasty

PURPOSE OF REVIEW

A successful reverse total shoulder arthroplasty requires careful preoperative planning and perioperative management. Preoperative comorbidity risks, perioperative pain management, and postoperative rehabilitation are all critical components of this arthroplasty. The current review examines available literature to guide the perioperative care of the reverse total shoulder arthroplasty patient.

RECENT FINDINGS

One of the most important advances for shoulder arthroplasty in recent years has been heightened awareness of various modalities for perioperative pain management. A number of recent studies have focused on the options for regional blockade as a critical tool for postoperative pain relief and the use of either continuous interscalene blocks or single shot blocks are supported. Additional studies are necessary to define the best local anesthetic agent and delivery mechanism to provide appropriate pain relief with a low side effect profile. Management of the patient throughout the perioperative course is a critical component in achieving better patient outcomes delivering high quality patient care. An orthopedic surgery team focused on perioperative management is better positioned to decrease adverse events and improve patient outcomes after reverse total shoulder arthroplasty.

What is the clinical impact of positive cultures at the time of primary total shoulder arthroplasty?

BACKGROUND

Cultures taken at the time of primary shoulder arthroplasty are commonly positive for Cutibacterium acnes. Despite our limited understanding of the clinical implication of deep tissue inoculation from dermal colonization, significant efforts have been made to decolonize the shoulder prior to surgery. The purpose of this study is to determine differences in clinical outcomes based on culture positivity at the time of primary shoulder arthroplasty.

METHODS

A series of 134 patients who underwent primary anatomic or reverse total shoulder arthroplasty and had intraoperative cultures obtained via a standard protocol were included. In each case, 5 tissue samples were collected and processed in a single laboratory for culture on aerobic and anaerobic media for 13 days. Minimum 2-year functional outcomes scores (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form [ASES] and Single Assessment Numeric Evaluation [SANE]) and reoperation data were analyzed.

RESULTS

Forty-two (31.3%) patients had positive cultures (30 C acnes and 21 with at least 2 positive cultures) at the time of surgery. There was no statistically significant difference in postoperative functional outcome scores (ASES: 82.5 vs. 81.9; P = .89, SANE: 79.5 vs. 82.1; P = .54) between culture-positive and culture-negative cohorts. There were no cases of infection. Two patients (4.8%; 2/42) with positive cultures required reoperation compared with 4 patients (5.6%; 4/71) without positive cultures.

CONCLUSION

The apparent colonization by nonvirulent organisms in patients undergoing primary shoulder arthroplasty does not appear to have a clinically significant effect on functional outcomes or need for repeat surgery in the short term.

Is there value in the routine practice of discarding the incision scalpel from the surgical field to prevent deep wound contamination with Cutibacterium acnes?

BACKGROUND

Cutibacterium acnes is found in skin flora of the shoulder and is the most common microbe identified in periprosthetic shoulder infections. The purpose of this study is to determine if there is C acnes present on the incision scalpel in patients undergoing shoulder arthroplasty despite extensive skin preparation techniques to prevent wound contamination.

METHODS

The authors collected a consecutive case series of patients meeting inclusion criteria. Patients were included if they underwent either primary or revision shoulder arthroplasty at the tertiary care hospital with the senior author during the study period. Culture swab samples, testing for presence of C acnes, were collected from 17 consecutive patients who underwent shoulder arthroplasty with a single fellowship-trained surgeon between November 2019 and March 2020. Culture reports were recorded as "positive" or "negative" after 21 days. Institutional review board approval of the study protocol was obtained. The null hypothesis was that there would be no cases with knife blades "culture positive" for C acnes.

RESULTS

17 patients were identified and fit inclusion criteria. There were 12 men (mean age 64.3 years, range 48-79 years) and 5 women (mean age 69.8 years, range 59-79 years). Two patients (11.8%) were found to have C acnes growth on the skin knife. Both patients were male and older than 70 years undergoing primary reverse shoulder arthroplasty with no history of previous shoulder infections.

CONCLUSION

The presence of C acnes on the skin blade in 2 patients validates concerns that there is C acnes present in dermal tissue despite extensive attention to eradication of these microbes. There was a high rate of C acnes contamination on scalpel blades used for initial skin incisions and the authors conclude that there is value in discarding these blades from the surgical field.

Is postoperative glucose variability associated with adverse outcomes following shoulder arthroplasty?

BACKGROUND

Postoperative infection after shoulder arthroplasty is a devastating complication. Multiple patient risk factors have been associated with postoperative infection, including increased body mass index and diabetes. Although the association between preoperative glucose control and infection has been established, little is known about the effect of perioperative glycemic control on outcomes following shoulder arthroplasty. The purpose of this study was to investigate the association between postoperative glycemic variability and short-term complications after total shoulder arthroplasty (TSA) and reverse total shoulder arthroplasty (RTSA).

METHODS

A retrospective study was performed at a large, single-specialty center from January 2015 to December 2018. Patients were included if they underwent primary TSA or RTSA with a minimum of 90 days' follow-up and had a minimum of 1 serum glucose value obtained per day of the hospital stay or had ≥3 measurements obtained during the hospital admission period. The primary outcome variable was postoperative infection per accepted definitions of surgical-site infection or periprosthetic joint infection. Secondary outcome variables included stiffness, periprosthetic fracture, periprosthetic dislocation, and reoperation.

RESULTS

In total, 1074 TSAs or RTSAs (in 1032 patients) met the eligibility criteria. The mean patient age was 69.9 ± 8.4 years, and 40.3% of patients had a preoperative diagnosis of diabetes mellitus. Of the patients, 670 (62%) had a calculable coefficient of variation. A younger patient age (median, 65 years [interquartile range (IQR), 13.5 years] vs. 71 years [IQR, 11.0 years]; P = .02) and a preoperative diagnosis of diabetes mellitus (P = .01) showed statistically significant associations with postoperative infection. The first in-hospital glucose measurement beyond the reference tertile of 70-140 mg/dL showed a statistically significant association with postoperative infection, with a median of 128.0 mg/dL (IQR, 43 mg/dL) vs. 167.5 mg/dL (IQR, 37.0 mg/dL; P = .01), whereas the second and third glucose measurements showed no association with postoperative infection. We found no associations between the coefficient of variation and reoperations or complications including surgical-site infection, periprosthetic joint infection, death, postoperative infection, periprosthetic fracture, or stiffness.

CONCLUSION

We found an association between a preoperative diagnosis of diabetes mellitus and postoperative infection following shoulder arthroplasty. We also found that an elevated first glucose measurement is associated with the development of postoperative infection. In-hospital glycemic control, as well as preoperative glycemic control and optimization, may be beneficial for reducing postoperative infections following shoulder arthroplasty.

Periprosthetic Infection After Reverse Shoulder Arthroplasty: a Review

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Cutibacterium acnes: a threat to shoulder surgery or an orthopedic red herring?

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.

Reduced Bacterial Burden of the Skin Surrounding the Shoulder Joint Following Topical Protocatechuic Acid Application: Results of a Pilot Study

Reducing the rising health-care burden associated with shoulder surgical site infection (SSI) is of paramount importance. The purpose of this study was to investigate the antimicrobial efficacy of protocatechuic acid (PCA) as a topical reagent for surgical skin antisepsis surrounding the shoulder joint.

Protocatechuic Acid as a Topical Antimicrobial for Surgical Skin Antisepsis: Preclinical Investigations

Background

There is a need for novel skin antiseptic agents to combat the health-care burdens associated with surgical site infection (SSI) and bacterial resistance. The purpose of this proof-of-principle pilot study was to investigate the potential of the phenolic compound protocatechuic acid (PCA) as a topical antimicrobial for surgical skin antisepsis.

Methods

The Kirby-Bauer method of disc diffusion was used to investigate the in vitro antimicrobial activity and comparative effectiveness of PCA and 7 related compounds against SSI pathogens. To explore the in vivo efficacy of topical PCA for providing deep, penetrating skin antisepsis, living Cutibacterium acnes was intradermally injected into the skin of female BALB/c mice. Mice were assigned to treatment with daily applications of topical PCA at 3 doses (78, 39, and 19.5 mM) or no treatment (n = 2 mice per group). After 96 hours, infected skin samples were harvested to compare mean C. acnes counts by treatment.

Results

Compared with other polyphenols, PCA demonstrated the broadest spectrum of antimicrobial activity against tested SSI pathogens, including drug-resistant organisms. At 96 hours following infection, the mean C. acnes burden in untreated mice was 6.65 log colony-forming units (CFUs) per gram of skin. Compared with the untreated group, daily topical application of 78 mM of PCA was associated with a significantly lower C. acnes CFU burden in mice skin (mean, 5.51 log CFUs per gram of skin; p = 0.0295). Both lower dosages of topical PCA failed to show an effect.

Conclusions

PCA demonstrated laboratory efficacy against pathogens implicated in SSI, including drug-resistant organisms. In vivo, topical PCA demonstrated dose-dependent skin penetration and antimicrobial activity against mouse skin C. acnes loads. Human clinical studies exploring the antimicrobial efficacy of topical PCA for preoperative shoulder skin antisepsis are warranted.

Clinical Relevance

Topical PCA may have the potential to improve current shoulder SSI treatment and prevention protocols.

Antibiotic prophylaxis in primary and revision shoulder replacement: a systematic review

Background

One of the most common bacteria responsible for most Periprosthetic joint infection (PJI) is Propionibacterium acnes. Even though the rate of infections in patients undergoing total shoulder arthroplasty is increasing, effective diagnostic tests and the precautions taken during the surgery are not yet adequate. This systematic review aims to evaluate the effectiveness of antimicrobial prophylaxis in PJI in shoulder replacement and to provide health workers with the best approach to the use of antimicrobial agents based on currently available clinical evidence.

Methods

a systematic review of the literature was carried out in accordance with the PRISMA Statement. Studies concerning the effectiveness of antimicrobial prophylaxis in the prevention of PJI in patients undergoing shoulder replacement were included.

Results

Seven studies were included in the final analysis because they were considered valid. A total of 3272 patients underwent a surgical procedure, most of which were males. The male population has a greater presence of hair, therefore a greater risk of P. acnes. in surface cultures. Patients were assessed at an average follow-up period of 20 months ranging from 9 weeks to 53 months.

Conclusion

The optimal perioperative antimicrobial regimen is controversial. The clinical guidelines recommend the use of only one antibiotic as prophylaxis but considering the increase in the rates of antibiotic-resistant infections, the question arises whether antibiotic prophylaxis should be extended for adequate coverage. Shoulder arthroplasty performed on the male population must be carefully checked after surgery for the possible presence of P. Acnes.

The presence of Cutibacterium acnes on the skin of the shoulder after the use of benzoyl peroxide: a placebo-controlled, double-blinded, randomized trial

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.

Strategies to decolonize the shoulder of Cutibacterium acnes: a review of the literature

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.

Perioperative Clindamycin Use in Penicillin Allergic Patients Is Associated With a Higher Risk of Infection After Shoulder Arthroplasty

BACKGROUND

This study determines whether infection rates differ between prophylactic antibiotic use for patients with or without penicillin allergy before shoulder arthroplasty surgery.

METHODS

Seven thousand one hundred forty primary shoulder arthroplasties operated between 2005 and 2016 were identified. We compared deep surgical site infection risk of patients who received perioperative vancomycin alone (6.2%, N = 444) or clindamycin alone (7.1%, N = 508) for penicillin allergy versus patients who received cefazolin alone without penicillin allergy (86.7%, N = 6,188).

RESULTS

Seventy deep infections (1.2% 5-year cumulative incidence) were observed. The most common organism was Cutibacterium acnes (39.4%, N = 27). Compared with patients treated with cefazolin, infection risk was not different for those treated with vancomycin (hazard ratio = 1.17, 95% confidence interval 0.42 to 3.30, P = 0.8), but a higher risk of infection was identified for those treated with clindamycin alone (hazard ratio = 3.45, 95% confidence interval 1.84 to 6.47, P < 0.001).

CONCLUSION

A higher risk of postoperative infection is found after prophylactic use of intravenous clindamycin antibiotic after shoulder arthroplasty. Vancomycin is preferred over clindamycin for patients with penicillin allergy.

LEVEL OF EVIDENCE

III, retrospective cohort study.

While home chlorhexidine washes prior to shoulder surgery lower skin loads of most bacteria, they are not effective against Cutibacterium (Propionibacterium)

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.

Incidence and predictors of positive intraoperative cultures in primary shoulder arthroplasty following prior ipsilateral shoulder surgery

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.

Cutibacterium acnes Infection in Orthopedics: Microbiology, Clinical Findings, Diagnostic Strategies, and Management

Cutibacterium (formerly called Propionibacterium) acnes is a human skin flora often implicated in orthopedic infections. The unique characteristics of this microorganism make the diagnosis of infection difficult. The diagnosis often is made based on clinical evidence, radiographic signs, and laboratory and/or surgical findings combined. Treatment often involves both pharmacologic and surgical methods. In addition, formation of biofilms and increased resistance to drugs exhibited by the microorganism can require combined antimicrobial therapy. Prophylactic measures are particularly important, but no single method has been shown to fully eliminate the risk of C acnes infections. Previous reports have focused on C acnes infections involving surgical implants or after certain orthopedic procedures, particularly in the shoulder and spine. This article reviews current clinical, diagnostic, and treatment principles for C acnes in orthopedics in general. [Orthopedics. 2020; 43(1):52-61.].

Advances and Update on Reverse Total Shoulder Arthroplasty

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 persists despite topical clindamycin and benzoyl peroxide

BACKGROUND

Cutibacterium (formerly Propionibacterium) acnes persists in the dermis despite standard skin antiseptic agents, prompting some surgeons to use topical antimicrobials such as benzoyl peroxide and clindamycin prior to shoulder arthroplasty surgery. However, the efficacy of these topical agents has not been established.

METHODS

The upper backs of 12 volunteers were randomized into 4 treatment quadrants: topical benzoyl peroxide, topical clindamycin, combination topical benzoyl peroxide and clindamycin, and a negative control. The corresponding topical agents were applied to each site twice daily for 3 days. A 3-mm dermal punch biopsy specimen was obtained from each site and cultured for 14 days to assess for C acnes growth. Positive cultures were assessed for the hemolytic phenotype. The McNemar test was used to compare the proportion of positive cultures in each group.

RESULTS

C acnes grew in 4 of 12 control sites (33.3%), 1 of 12 benzoyl peroxide sites (8.3%), 2 of 12 clindamycin sites (16.7%), and 2 of 12 combination benzoyl peroxide-clindamycin sites (16.7%). The C acnes hemolytic phenotype was present in 2 of 12 control specimens (16.7%) compared with 0 (0.0%) in the benzoyl peroxide group, 2 of 12 (16.7%) in the clindamycin group, and 2 of 12 (16.7%) in the combination benzoyl peroxide-clindamycin group. There were no statistically significant differences between treatment arms.

CONCLUSION

The topical application of benzoyl peroxide and clindamycin did not eradicate C acnes in all subjects. The clinical implications of these findings are yet to be determined.

Arthroscopy of the symptomatic shoulder arthroplasty

BACKGROUND

Assessment of a painful or stiff shoulder arthroplasty can be challenging. The cause of pain can sometimes be easily identified. However, some patients have normal levels of inflammatory markers, normal plain films, and no clinical signs to indicate a diagnosis. Indolent organisms may not raise blood marker levels or result in obvious radiologic findings such as loosening. We report the utility of performing arthroscopy in these patients for a diagnostic advantage.

METHODS

We retrospectively reviewed the health records of all patients who underwent diagnostic shoulder arthroscopy over a 3-year period. Patients were included if they were aged 18 years or older, had undergone previous arthroplasty surgery, and had symptoms of shoulder pain or stiffness. Patients were excluded if they had any traditional symptoms of infection or had a raised serum white cell count or C-reactive protein level prior to diagnostic arthroscopy.

RESULTS

Fourteen patients met the initial inclusion criteria. The mean interval between index surgery and arthroscopic evaluation was 65.4 months (standard deviation, 58 months; range, 17-192 months). Arthroscopic biopsy specimens returned positive culture results in 3 patients (21%). Rotator cuff tears were noted in 8 patients (57%). Capsular contraction requiring release was noted in 2 patients (10%). In all patients, the diagnostic arthroscopy directed the next stage of management.

CONCLUSIONS

Diagnostic arthroscopy allows a full assessment of implants, the rotator cuff, the native articular surfaces, and scar tissue, as well as biopsy specimens to be obtained for indolent infection, in patients considering revision arthroplasty surgery. This allows a more informative consent process for patients, directs surgical management, and on occasion, allows for therapeutic intervention in a painful or stiff shoulder arthroplasty.

Hydrogen peroxide skin preparation reduces Cutibacterium acnes in shoulder arthroplasty: a prospective, blinded, controlled trial

BACKGROUND

The purpose of this study was to determine whether preoperative skin preparation with hydrogen peroxide reduces intraoperative culture positivity for Cutibacterium acnes in shoulder arthroplasty.

METHODS

This was a prospective, controlled, parallel/noncrossover, nonrandomized, single-blinded trial registered at clinicaltrials.gov. We included a consecutive series of patients scheduled to undergo primary anatomic or reverse total shoulder arthroplasty. The first group of patients underwent a standard skin preparation and the second group underwent the same preparation with the addition of hydrogen peroxide. We then took skin, dermis, glenohumeral joint, and air (negative control) aerobic and anaerobic culture swabs. We blinded the laboratory analyzing the samples. An a priori power analysis determined that 56 patients would be needed to see a 50% reduction in culture positivity rates. We also conducted a post hoc gender-stratified analysis.

RESULTS

Between January 2017 and October 2018, the authors performed 124 primary shoulder arthroplasties, of which we included 65 and collected samples on 61. There were no demographic differences. There were fewer patients within the peroxide group with triple-positive cultures (skin, dermis, and joint) (0% vs. 19%, P = .024) and positive cultures from the joint (10% vs. 35%, P = .031). In our subgroup analysis, these differences were only significant in males. The vast majority of positive cultures were with C. acnes.

CONCLUSION

Although larger, randomized studies are needed, adding hydrogen peroxide to the preoperative skin preparation may be a low-cost, low-risk method to reduce deep tissue contamination with C. acnes, particularly within males.

Bactericidal efficacy of hydrogen peroxide on Cutibacterium acnes

Objectives

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.Cite this article: P. Hernandez, B. Sager, A. Fa, T. Liang, C. Lozano, M. Khazzam. Bactericidal efficacy of hydrogen peroxide on Cutibacterium acnes. Bone Joint Res 2019;8:3-10. DOI: 10.1302/2046-3758.81.BJR-2018-0145.R1.