Management of deep postoperative shoulder infections: is there a role for open biopsy during staged treatment?

One- vs. Two-Stage Revision for Periprosthetic Shoulder Infections: A Systematic Review and Meta-Analysis

Periprosthetic shoulder infection (PSI) remains a challenging complication after shoulder arthroplasty. Therapeutic options include one- or two-stage revision, irrigation and debridement, and resection arthroplasty. With our systematic review and meta-analysis, we aimed to compare one- and two-stage revisions for periprosthetic shoulder joint infections and determine the most appropriate therapeutic procedure. We performed an extensive literature search in PubMed, Ovid Medline, Cochrane Library, Web of Science, and CINAHL and filtered out all relevant studies. The meta-analysis was performed using the random-effects model, heterogeneity was analyzed using I2, and publication bias was assessed using the Egger's test. A total of 8 studies with one-stage revisions, 36 studies with two-stage revisions, and 12 studies with both one-stage and two-stage revisions were included. According to the random-effects model, the reinfection rate for the entirety of the studies was 12.3% (95% Cl: 9.6-15.3), with a low-to-moderate heterogeneity of I2 = 47.72%. The reinfection rate of the one-stage revisions was 10.9%, which was significantly lower than the reinfection rate of the two-stage revisions, which was 12.93% (p = 0.0062). The one-stage revision rate was significantly lower with 1.16 vs. 2.25 revisions in the two-stage revision group (p < 0.0001). The postoperative functional outcome in one-stage-revised patients was comparable but not statistically significant (p = 0.1523). In one- and two-stage revisions, most infections were caused by Cutibacterium acnes. In summary, our systematic review and meta-analysis show the superiority of single-stage revision regarding reinfection and revision rates in periprosthetic shoulder joint infection.

Periprosthetic shoulder infection management: one-stage should be the way: a systematic review and meta-analysis

BACKGROUND

There is still no consensus among surgeons on whether to perform a 1- or 2-stage surgical revision in infected shoulder arthroplasties. The aim of this systematic review and meta-analysis is to rigorously synthesize published studies evaluating the clinical outcomes, recurrence of infection, and other clinical complications in order to discuss which is the best strategy for treating periprosthetic joint infection after shoulder arthroplasty.

METHODS

Upon research using the PubMed, Scopus, and Web of Science databases, in November 2022, studies that presented 1- or 2-stage surgical revision as a treatment for periprosthetic joint infection after shoulder arthroplasty and assessed the reinfection rate on these patients, as well as other clinical outcomes, with a minimum follow-up of 12 months, were included. Study quality was evaluated using the Methodological Index for Non-Randomized Studies (MINORS) score. Reinfection and complication rates were extracted, and pooled estimates were calculated using the random-effect model.

RESULTS

After careful screening, 44 studies were included, 5 reporting on 1-stage and 30 on 2-stage revisions and 9 assessing both strategies. A total of 185 shoulders were reported in 1-stage revision studies, whereas 526 shoulders were reported in 2-stage revision studies. The overall pooled random-effects reinfection rate was 6.68% (95% confidence interval [CI]: 3.76-10.13), with low heterogeneity (I2 = 28%, P = .03). One-stage revision showed a reinfection rate of 1.14% (95% CI: 0.00-4.88), whereas 2-stage revision analysis revealed a reinfection rate of 8.81% (95% CI: 4.96-13.33). There were significant statistical differences between 1- and 2-stage reinfection rates (P = .04). The overall pooled rate for other clinical complications was 16.76% (95% CI: 9.49-25.15), with high heterogeneity (I2 = 70%, P < .01). One-stage revision had a complication rate of 6.11% (95% CI: 1.58-12.39), whereas the 2-stage revision complication rate was 21.26% (95% CI: 11.51-32.54). This difference was statistically significant (P = .03).

CONCLUSIONS

This is the first systematic review and meta-analysis showing significant statistical differences between 1- and 2-stage surgical revision in infected shoulder arthroplasties. Provided the right conditions exist, 1-stage revision shows better results in infection control, with lower clinical complications and possible better clinical outcomes.

Chronological changes in the rate of surgical field contamination in the shoulder joint

BACKGROUND

In shoulder surgery, low-virulence bacteria such as Cutibacterium acnes and coagulase-negative staphylococci can cause postoperative infection. However, the degree of sterility during surgery after disinfection is not known, and the efficacy of double skin preparation for such bacteria is unclear. This study aimed to evaluate chronological changes in the surgical field contamination rate in the shoulder joint and to compare single and double skin preparation.

METHODS

In total, 126 shoulders in 121 patients undergoing shoulder surgery (64 men, 62 women; mean age 64 years) were enrolled. Patients were divided into two groups: single skin preparation, where the site was painted with 10% povidone iodine, and double skin preparation, where the site was treated with 1% chlorhexidine gluconate/83% isopropyl alcohol and painted 10% povidone iodine. Swab samples from the axillary and proximal areas in the surgical field were collected chronologically before starting surgery and at 30, 60, and 120 min after starting surgery (MAS). The contamination rate of each sample was compared and detected species were evaluated.

RESULTS

The contamination rate for the axillary area was 48.4%, 85.9%, 95.3%, and 97.1% in the single-preparation group and 32.3%, 72.6%, 87.1%, and 91.2% in the double-preparation group before starting surgery and 30, 60, and 120 MAS, respectively, and that the proximal area was 12.5%, 26.6%, 29.7%, and 35.3% in the single-preparation group and 16.1%, 19.4%, 27.4%, and 38.2% in the double-preparation group, respectively. Significant differences were not seen between the groups by area or time point. Most detected species were Cutibacterium acnes and coagulase-negative staphylococci.

CONCLUSIONS

The incidence of surgical field contamination in shoulder joint was high from immediately after starting surgery. In the axillary area, the contamination rates exceeded 70% from 30 MAS in both groups. Measures against infection should be instituted considering these findings when performing shoulder surgery.

Management of periprosthetic joint infection of shoulder arthroplasty: Single-stage versus two-stage protocols. A systematic review and meta-analysis of the literature

Background

The treatment of shoulder prosthetic joint infections (PJIs) requiring removal of the prosthesis is not well defined. This article aims to systematically review and compare the results of the literature in single-stage and two-stage protocols in the treatment of shoulder PJI.

Methods

An in-depth search on PubMed/Scopus/Web of Science databases and cross-referencing search was carried out concerning the articles reporting detailed data on the topic.

Results

A total of 486 shoulder PJIs were included: 137 treated with single-stage and 349 with two-stage procedure. A similar distribution between early and not-early infections (19.1% vs 80.9%) was found between the two groups. The overall rate of success in terms of PJI eradication was significantly higher in the single-stage group (95.6% vs 85.7%, p < 0.001). The non-infection-related complications rate was 13.8% in the single-stage group and 37.6% in the two-stage group (p < 0.001), the non-infection-related revision rate was 8% and 18.9%, respectively (p = 0.005).

Discussion

The single-phase protocol showed a higher success rate in eradicating the infection and a lower complication rate. However, the low number of patients included, the low quality of the articles, the lack of data on clinical severity and bacteriological virulence suggest caution in conclusions.

Preventing and Treating Infection in Reverse Total Shoulder Arthroplasty

PURPOSE OF REVIEW

Periprosthetic infection after shoulder arthroplasty is relatively uncommon though associated with severe long-term morbidity when encountered. The purpose of the review is to summarize the recent literature regarding the definition, clinical evaluation, prevention, and management of prosthetic joint infection after reverse shoulder arthroplasty.

RECENT FINDINGS

The landmark report generated at the 2018 International Consensus Meeting on Musculoskeletal Infection has provided a framework for diagnosis, prevention, and management of periprosthetic infections after shoulder arthroplasty. Shoulder specific literature with validated interventions to reduce prosthetic joint infection is limited; however existing literature from retrospective studies and from total hip and knee arthroplasty allows us to make relative guidelines. One and two-stage revisions seem to demonstrate similar outcomes; however, no controlled comparative studies exist limiting the ability to make definitive recommendations between the two options. We report on recent literature regarding the current diagnostic, preventative, and treatment options for periprosthetic infection after shoulder arthroplasty. Much of the literature does not distinguish between anatomic and reverse shoulder arthroplasty, and further high-level shoulder specific studies are needed to answer questions generated from this review.

Patient-specific articulating spacer for two-stage shoulder arthroplasty exchange

OBJECTIVE

Two-stage exchange with an antibiotic-loaded polymethylmethacrylate (PMMA) spacer is standard treatment for chronic periprosthetic joint infection of the shoulder. We present a safe and simple technique for patient-specific spacer implants.

INDICATION

(Chronic) periprosthetic joint infection of the shoulder.

RELATIVE CONTRAINDICATIONS

Known allergy against components of PMMA bone cements. Inadequate compliance for two-stage exchange. Patient is unfit to undergo two-stage exchange.

SURGICAL TECHNIQUE

Hardware removal, histologic and microbiologic samples, and debridement. Preparation of targeted or calculated antibiotic-loaded PMMA. Tailoring of patient-specific spacer. Spacer implantation.

POSTOPERATIVE MANAGEMENT

Rehabilitation protocol. Antibiotic treatment. Reimplantation after successful eradication of infection.

Antibiotic Spacers for Shoulder Periprosthetic Joint Infection: A Review

Periprosthetic joint infection is a rare but potentially devastating complication of shoulder arthroplasty. The most conservative treatment approach is a two-stage revision involving interval placement of an antibiotic cement spacer. The purpose of this study was to contextualize the use of antibiotic spacers in the current treatment paradigm of shoulder periprosthetic joint infection and to review the history of shoulder spacers, the different types (eg, stemmed versus stemless and prefabricated versus handmade), the antibiotic composition and dosage, and their efficacy and complications.

Short-term outcomes of two-stage reverse total shoulder arthroplasty with antibiotic-loaded cement spacer for shoulder infection

Background

The purpose of our study was to investigate short-term outcomes of two-stage reverse total shoulder arthroplasty (RTSA) with an antibiotic-loaded cement spacer for shoulder infection.

Methods

Eleven patients with shoulder infection were treated by two-stage RTSA following temporary antibiotic-loaded cement spacer. Of the 11 shoulders, nine had pyogenic arthritis combined with complex conditions such as recurrent infection, extensive osteomyelitis, osteoarthritis, or massive rotator cuff tear and two had periprosthetic joint infection (PJI). The mean follow-up period was 29.9 months (range, 12–48 months) after RTSA. Clinical and radiographic outcomes were evaluated using the visual analog scale (VAS) score for pain, American Shoulder and Elbow Surgeons (ASES) score, subjective shoulder value (SSV), and serial plain radiographs.

Results

The mean time from antibiotic-loaded cement spacer to RTSA was 9.2 months (range, 1–35 months). All patients had no clinical and radiographic signs of recurrent infection at final follow-up. The mean final VAS score, ASES score, and SSV were significantly improved from 4.5, 38.6, and 29.1% before RTSA to 1.7, 75.1, and 75.9% at final follow-up, respectively. The mean forward flexion, abduction, external rotation, and internal rotation were improved from 50.0°, 50.9°, 17.7°, and sacrum level before RTSA to 127.3°, 110.0°, 51.8°, and L2 level at final follow-up, respectively.

Conclusions

Two-stage RTSA with antibiotic-loaded cement spacer yields satisfactory short-term clinical and radiographic outcomes. In patients with pyogenic arthritis combined with complex conditions or PJI, two-stage RTSA with an antibiotic-loaded cement spacer would be a successful approach to eradicate infection and to improve function with pain relief.

Diagnosis of orthopaedic-implant-associated infections caused by slow-growing Gram-positive anaerobic bacteria - a clinical perspective

Slow-growing Gram-positive anaerobic bacteria (SGAB) such as Cutibacterium acnes are increasingly recognized as causative agents of implant-associated infections (IAIs) in orthopaedic surgeries. SGAB IAIs are difficult to diagnose because of their non-specific clinical and laboratory findings as well as the fastidious growth conditions required by these bacteria. A high degree of clinical suspicion and awareness of the various available diagnostic methods is therefore important. This review gives an overview of the current knowledge regarding SGAB IAI, providing details about clinical features and available diagnostic methodologies. In recent years, new methods for the diagnosis of IAI were developed, but there is limited knowledge about their usefulness in SGAB IAI. Further studies are required to determine the ideal diagnostic methodology to identify these infections so that they are not overlooked and mistakenly classified as aseptic failure.

One Versus 2-Stage Revision for Shoulder Arthroplasty Infections: A Systematic Review and Analysis of Treatment Selection Bias

BACKGROUND

There is controversy regarding the optimal treatment for infection following shoulder arthroplasty. The purpose of this systematic review is to analyze the bias in treatment selection, infection clearance rates, and functional outcomes after 1 versus 2-stage revision surgery for periprosthetic shoulder infections.

METHODS

A systematic search strategy following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted in 4 phases. Articles were identified using MEDLINE (PubMed), Embase (Elsevier), and Cochrane Library databases with Boolean search terms related to infection after shoulder arthroplasty. Included articles were analyzed for quality, and data were extracted for use. Preoperative treatment selection bias was analyzed and postoperative infection clearance rates and functional outcome scores were compared between 1 and 2-stage revision surgery for periprosthetic shoulder infection.

RESULTS

Overall, 163 1-stage shoulder procedures and 289 2-stage shoulder procedures were included in the analysis. Cutibacterium acnes was the organism most frequently grown on culture (37%) followed by coagulase-negative Staphylococcus (19%). The overall infection clearance rate was 95.6% for 1-stage and 85.2% for 2-stage procedures. In a comparison of the change in outcome scores from preoperatively to postoperatively between 1-stage and 2-stage revision, the Constant-Murley Score (CMS) improved 21.0 points (1-stage) versus 22.8 points (2-stage), the American Shoulder and Elbow Surgeons (ASES) score improved 26.2 points versus 33.6 points, and the Simple Shoulder Test (SST) score improved 3.5 points versus 6.4 points, respectively. Overall, 23 of 26 studies cited a reason for selection of a 1 versus 2-stage procedure, which was due to standard treatment protocol in 10 studies, based on the timing of the infection (acute versus subacute versus chronic) in 5, due to a combination of factors (age, comorbidities, intraoperative appearance, adequacy of debridement, bone loss) in 6, and due to preoperative identification of a specific organism in 2.

CONCLUSIONS

One-stage revisions resulted in higher infection clearance rates; however, 2-stage revisions resulted in greater functional improvement as measured with ASES and SST scores from the preoperative assessment to the final postoperative follow-up. The decision between 1 and 2-stage revisions is due to a combination of factors including pathogen type, timing of infection, findings on the preoperative clinical examination, the patient's own decision, the surgeon's preference, and the intraoperative soft-tissue/osseous appearance, which may have biased the overall results. There is no consensus in the literature on the decision between 1 and 2-stage treatment for periprosthetic shoulder infection, which is based on a combination of factors. However, both treatment strategies are effective in treating periprosthetic shoulder infection.

LEVEL OF EVIDENCE

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

Role of pre-revision tissue biopsy in evaluation of painful shoulder arthroplasty: a systematic review and meta-analysis

BACKGROUND

Pre-revision tissue biopsy (PTB) for culture has been used as a diagnostic tool in the evaluation for periprosthetic joint infection among patients with a painful shoulder arthroplasty. The purpose of this study was to (1) determine the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of PTB culture results compared with results of "gold-standard" tissue biopsy for culture taken at the time of subsequent revision surgery (TBR), and (2) report the current indications and protocols described for use of PTB. The hypothesis was that PTB culture results would correlate highly with results of TBR and that protocols for PTB would vary by institution.

METHODS

By use of Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, a systematic review and meta-analysis of English-language literature were performed using the Embase, MEDLINE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Cochrane databases from inception through March 2020. Methodological Index for Non-randomized Studies (MINORS) validated grading criteria were used to summarize the quality and bias of included studies. Studies were included if an arthroscopic or open tissue biopsy was performed in patients who had previously undergone anatomic total shoulder arthroplasty, shoulder hemiarthroplasty, or reverse total shoulder arthroplasty as a separate procedure prior to revision of components, if applicable. Meta-analysis to identify the sensitivity, specificity, NPV, and PPV of PTB was performed. Analysis was performed by first defining 1 positive PTB culture result as infection and then defining 2 positive culture results as infection.

RESULTS

A total of 1751 titles were screened, and 66 full-text articles were reviewed for inclusion. Four total studies encompassing 72 cases met the inclusion criteria. All studies were small (N = 13 to N = 23), retrospective series, with all but 12 biopsies performed arthroscopically. Sixty-five patients (90.2%) underwent subsequent revision surgery and TBR. Of these patients, 23 (35.4%) had ≥1 positive culture result with PTB and TBR. By this definition, the sensitivity of PTB was 92.0% (95% confidence interval [CI], 72.5%-98.6%); specificity, 70.0% (95% CI, 53.3%-82.9%); PPV, 65.7% (95% CI, 47.7%-80.3%); and NPV, 93.3% (95% CI, 76.5%-98.8%). For 2 positive PTB results, the sensitivity of PTB was 100% (95% CI, 51.7%-100%); specificity, 50.0% (95% CI, 31.4%-68.6%); PPV, 33.3% (95% CI, 14.4%-58.8%); and NPV, 100% (95% CI, 69.9%-100%). No complications of PTB were reported. The mean Methodological Index for Non-randomized Studies (MINORS) grade was 11.4 (range, 8.5-14).

CONCLUSION

PTB is a sensitive diagnostic modality with a high NPV that may aid in the diagnosis of shoulder periprosthetic joint infection in patients with a painful shoulder arthroplasty. Given the disparate biopsy protocols, greater standardization of clinical best practices and broader prospective studies are necessary to define the future role of PTB in dictating treatment.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSION

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

The management of infected shoulder arthroplasty by two-stage revision

BACKGROUND

There remains no gold standard management for deep shoulder periprosthetic joint infection (PJI). This case series aims to present our experience of two-stage revision arthroplasty, including eradication of infection and reoperation rates.

METHODS

We retrospectively reviewed patients undergoing revision arthroplasty for shoulder PJI between 2006 and 2015. Cases were confirmed using Musculoskeletal Infection Society (MSIS) and American Academy of Orthopaedic Surgeons (AAOS) guidelines. TSA removal, debridement and irrigation preceded antibiotic-loaded cement spacer insertion and a minimum of six weeks intravenous antibiotics. Reimplantation was performed as a second stage following a negative aspirate.

RESULTS

Twenty-eight patients underwent a first stage procedure (mean age 69 years; 16 male, 12 female). Propionibacterium acnes, Methicillin-sensitive Staphylococcus aureus, Coagulase-negative Staphylococcus and Staphylococcus epidermidis were the commonest microorganisms cultured. Five cases had mixed growths and six cases provided no growth. Three patients did not proceed to a second stage. Twenty-five patients underwent reimplantation (mean interval 6.7 months), with 80% remaining infection-free (mean follow-up 38.3 months).

DISCUSSION

Managing complex and late presentation shoulder PJI with two-stage revision is associated with high rates of infection eradication (80%). In the absence of a management consensus, our experience supports two-stage revision arthroplasty for eradicating infection in this complex patient group.

The In Vitro Efficacy of Doxycycline over Vancomycin and Penicillin in the Elimination of Cutibacterium Acnes Biofilm

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.

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

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.

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.

[Two-stage reverse total shoulder arthroplasty for treating postoperative deep infection after internal fixation of proximal humeral fracture]

OBJECTIVE

To summarize the effectiveness of two-stage reverse total shoulder arthroplasty for treating postoperative deep infection after internal fixation of the proximal humeral fracture.

METHODS

Between June 2014 and January 2018, 17 patients with deep infection and humeral head necrosis or bone nonunion after internal fixation of proximal humeral fractures were treated. There were 8 males and 9 females, aged from 52 to 78 years (mean, 63.8 years). The infection occurred at 19-66 months after the initial internal fixation (mean, 34.8 months). Microbial culture of joint fluid was positive in 14 cases and negative in 3 cases. The preoperative Constant score, American shoulder and elbow surgeons (ASES) score, and visual analogue scale (VAS) score were 36.41±8.65, 31.06±7.43, and 7.29±0.99, respectively. The preoperative ranges of forward flexion, abduction, external rotation were (45.88±12.46), (42.18±12.31), and (16.76±4.92)°, respectively. The preoperative range of internal rotation was buttock in 9 cases, lumbosacral joint in 3 cases, L 3 in 5 cases. At the first-stage surgery, the thorough debridement was done and the antibiotic-impregnated bone cement spacer was placed after the removal of internal fixation. After the infections disappeared, the two-stage reverse total shoulder arthroplasty was performed. The mean interval between the two procedures was 4.2 months (range, 3.0-6.5 months).

RESULTS

All the incisions healed primarily and no complications such as recurrent infection or vascular nerve injury occurred. All patients were followed up 15-32 months (mean, 22.0 months). At last follow-up, the ranges of forward flexion, abduction, and external rotation were (109.00±23.66), (98.53±16.92), (41.41±6.82)°, respectively; and the range of internal rotation was lumbosacral joint in 5 cases, L 3 in 8 cases, T 12 in 4 cases. The range of motion of shoulder joints at last follow-up was significant improved when compared with the preoperative range of motion ( P<0.05). The Constant score (64.88±8.70), ASES score (65.18±8.10), and VAS score (2.94±1.25) were significantly superior to the preoperative scores ( P<0.05). X-ray films showed that no prosthesis loosening occurred.

CONCLUSION

Two-stage reverse total shoulder arthroplasty is an effective treatment for the postoperative deep infection after internal fixation of the proximal humeral fracture, which has advantages of low risk of infection recurrence, good shoulder function, and satisfactory short-term effectiveness.

Failed Reverse Shoulder Arthroplasty and Recommendations for Revision

PURPOSE OF REVIEW

The most common complications warranting revision consideration in reverse shoulder arthroplasty (RSA) include instability and its associated causes: infection, periprosthetic fracture, and glenoid baseplate loosening. Management of complications can be challenging and the nuances of treatment are still being elucidated. The focus of this paper is to review the treatment of the failed RSA and discuss evidence-based recommendations for revision.

RECENT FINDINGS

The most common complications requiring revision RSA are instability and infection. The causes for instability can be subdivided into three main subcategories: loss of compression, loss of containment, and impingement. Loss of compression is further broken down into 6 subcategories revolving around abnormal prosthesis positioning, undersized prostheses, or intrinsic soft-tissue tension loss leading to instability. Periprosthetic infection can also lead to instability, yet the most appropriate management for infected RSA remains controversial. Restoring stability by maximizing deltoid and soft tissue tension while avoiding impingement revolves around three basic methods: (1) lateralizing and/or upsizing the glenosphere to an inferior position on the glenoid, (2) use of a more constrained polyethylene insert, and (3) distalizing the humerus by increasing the polyethylene thickness and/or the thickness of the humeral tray. Management of periprosthetic joint infection can be performed in one-stage, two-stage, or "three-stage" procedures all showing good outcomes with two-stage procedures being the most commonly performed. However, persistent positive culture with propriobacterium acnes can occur in up to 25% of cases. In order to limit the associated morbidity from failed revision reverse shoulder arthroplasty, continued research on best management of associated complications is warranted.

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.].

Investigating clinical characteristics and prognostic factors in patients with chronic osteomyelitis of humerus

Background

Chronic osteomyelitis in the humerus, which has complex neuroanatomy and a good soft tissue envelope, represents a unique clinical challenge. However, there are relatively few related studies in the literature. This article retrospectively reviewed a large case series with the aims of sharing our management experiences and further determining factors associated with the outcomes.

Methods

Twenty-eight consecutive adult patients with a mean age of 36 years were identified by reviewing the osteomyelitis database of our clinic centre. The database was used to prospectively identify all osteomyelitis cases between 2013 and 2017, and all data then was retrospectively analysed.

Results

The mean follow-up period was 35 months (range 24–60). The aetiology was trauma in 43% (12) of the patients and haematogenous in 57% (16) of the patients, and Staphylococcus aureus was a solitary agent in 50% (14) of the patients. Host-type (Cierny’s classification) was IA in 8, IIIB in 11 and IVB in 9 patients. All patients required debridement followed by the placement of a temporary antibiotic-impregnated cement spacer (rod). Seventeen patients received a cement-coated plate for internal fixation after debridement, and 13 patients needed bone grafts when the spacer was staged removed. All patients attained an infection-free bone healing state at the final follow-up. The final average DASH (disabilities of the arm, shoulder and hand) score was 18.14 ± 5.39, while 6 patients (two developed traumatic olecranarthritis, four developed radial nerve injuries) showed the lowest levels of limb function (p = 0.000) and were unemployed. Three patients (type I; significant difference between type I versus type III and type IV patients, p < 0.05) experienced recurrence after debridement and underwent a second revision, which was not related to the bone graft (p = 0.226) or plate fixation (p = 0.050).

Conclusions

Humeral chronic osteomyelitis can be treated with general surgery and anti-infective therapy; medullary (type I) infection presents a challenge, and the antibiotic-coated cement plate provides favourable fixation without increasing recurrence of infections. Clinicians should be aware of potential iatrogenic nerve injuries when treating these patients with complicated cases, and an experienced surgeon may improve the outcome.

Periprosthetic Infections of the Shoulder: Diagnosis and Management

The use of shoulder arthroplasty is continuing to expand. Periprosthetic joint infection of the shoulder is a devastating complication occurring in approximately 1% of cases. The most common organisms responsible for the infection are Cutibacterium acnes (formerly Propionibacterium acnes) (∼39%) and coagulase-negative Staphylococcus (∼29%). Evaluation of patients includes history and physical examination, serologic testing, imaging, possible joint aspiration, and tissue culture. Diagnosing infections caused by lower virulence organisms (eg, C acnes) poses a challenge to the surgeon because traditional diagnostic tests (erythrocyte sedimentation rate, C-reactive protein, and joint aspiration) have a low sensitivity due to the lack of an inflammatory response. Periprosthetic joint infections of the shoulder due to Staphylococcus aureus and other highly virulent organisms are often easy to diagnose and are usually treated with two-stage revisions. However, for infections with C acnes and coagulase-negative Staphylococcus, single- and two-stage revision surgeries have shown similar ability to clear the infection. Unexpected positive cultures for C acnes during revision surgery are not uncommon; the proper management is still under investigation and remains a challenge.

Proceedings from the 2018 International Consensus Meeting on Orthopedic Infections: evaluation of periprosthetic shoulder infection

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.

Scoping review: Diagnosis and management of periprosthetic joint infection in shoulder arthroplasty

BACKGROUND

The aim of this scoping review is to assess the current evidence regarding periprosthetic shoulder infection to inform development of evidence and consensus-based guidelines.

METHODS

A search of Medline, Embase and PubMed was performed; two authors screened the results independently for inclusion.

RESULTS

Totally 88 studies were included. Incidence of periprosthetic shoulder infection ranged from 0.7% to 7%. The most common organisms to cause periprosthetic shoulder infection were Propionibacterium acnes, Staphylococcus aureus, Staphylococcus epidermidis and coagulase-negative Staphylococcus. Male gender and younger age are the most reported risk factors. Erythrocyte sedimentation rate, C-reactive protein and serum/synovial biomarkers had limited diagnostic accuracy. Thirty-nine studies reported the outcome of surgical management of periprosthetic shoulder infection. Eradication rates vary from 54% to 100% for debridement procedures; 66-100% for permanent spacers; 50-100% following single-stage revision; 60-100% following two-stage revision; and 66-100% following resection arthroplasty.

CONCLUSION

There is wide heterogeneity in study designs and outcomes of studies are often contradictory and due to issues with methodology and small sample sizes the optimal pathways for diagnosis and management cannot be determined from this review. Future research should be based on larger cohorts and randomised trials where feasible to provide more valid research for guiding future treatment of periprosthetic shoulder infection.

Outcomes of revision surgery after periprosthetic shoulder infection: a systematic review

BACKGROUND

Periprosthetic shoulder infection (PSI) is one of the most challenging complications after shoulder arthroplasty. Different treatments have been proposed, but the best surgical procedure remains disputed in the current literature. This systematic review investigated the outcomes of revision surgery after PSI.

METHODS

The PubMed and Scopus databases were used to search keywords in April 2018. Of 2157 titles, 34 studies were finally analyzed. Demographics, laboratory and microbiological data, types of implants, surgical techniques with complications and reoperations, eradication rates, and clinical and functional outcomes were reported.

RESULTS

A total of 754 patients were identified. Cutibacterium acnes (C. acnes) was the most common microorganism found both in PSI (33%) and persistent infections (40%). Preoperatively, C-reactive protein was elevated in 70% of patients with PSI. Reverse shoulder arthroplasty had a lower prevalence of infection (P < .001). The eradication rate was 96% with 1 stage, 93% with permanent spacers, 86% with 2 stages, 85% with resection arthroplasty, and 65% with irrigation and débridement. One-stage revision was the best treatment, considering postoperative flexion and abduction, compared with resection arthroplasty, permanent spacers, and 2-stage revision. One-stage revision showed fewer postoperative complications than irrigation and débridement, resection arthroplasty, and 2-stage surgery. Two-stage surgery was the most common treatment, and the functional score demonstrated no differences between 2-stage and 1-stage procedures.

CONCLUSIONS

Our review suggests that a 1-stage procedure should be recommended to treat PSI. Two-stage revision could be reserved for select cases in which the bacterium involved is unknown.

Proceedings from the 2018 International Consensus Meeting on Orthopedic Infections: management of periprosthetic shoulder infection

The Second International Consensus Meeting on Orthopedic Infections was held in Philadelphia, Pennsylvania, in July 2018. A multidisciplinary team of international experts from all 9 subspecialties of orthopedic surgery and allied fields of infectious disease, microbiology, and epidemiology was assembled to form the International Consensus Group. The following consensus proceedings from the International Consensus Meeting involve 30 questions pertaining to the management of periprosthetic shoulder infection.

Cutibacterium (formerly Propionibacterium) acnes clavicular infection

Cutibacterium (formerly Propionibacterium) acnes^{13, 16} is a slow growing, gram-positive bacteria that is naturally found in higher concentrations as skin flora on the chest and back, as well as in other areas with greater numbers of hair follicles.^{25, 37} Most of the reported cases of C. acnes shoulder girdle infection follow arthroplasty surgery,^{18, 20, 26, 27, 32, 35} which then often requires debridement, administration of intravenous antibiotics, and surgical revision of the implanted device.^{12, 15, 21, 28-30} In a recent study, 56% of 193 shoulder revisions had a positive culture, 70% of which grew C. acnes.³⁰ Despite the relatively common presumed association of C. acnes humeral osteomyelitis with prosthetic infection, infection of the scapula or clavicle secondary to C. acnes is rare.^{4, 23, 36} Osteomyelitis of the clavicle involving any organism is also an uncommon event that can arise spontaneously via presumed hematogenous spread, or secondary to open fractures or internal fixation.^{6, 33} The most commonly found organism in clavicular osteomyelitis is Staphylococcus aureus.⁹ We here report two cases of clavicular infection secondary to C. acnes that were not associated with implants.

Outcomes of revision arthroplasty for shoulder periprosthetic joint infection: a three-stage revision protocol

BACKGROUND

This study evaluated outcomes after treatment of shoulder periprosthetic joint infection (PJI) with a 3-stage revision protocol consisting of (1) débridement, explantation, and cement spacer placement, followed by parenteral antibiotics; (2) open biopsy and débridement; and (3) reimplantation if cultures were negative. We hypothesized this protocol would eradicate persistent infection while producing excellent functional and subjective outcomes, and there would be no difference in these parameters for patients with shoulder PJI compared with patients with revision for aseptic indications.

METHODS

We retrospectively analyzed a prospectively collected revision shoulder arthroplasty cohort to identify shoulder PJI patients treated with a 3-stage protocol. Demographics, culture data, range of motion, and patient-reported outcomes were collected. Outcomes for patients with shoulder PJI and revision to RTSA were compared with patients revised to RTSA for noninfectious indications. Significance was defined as P < .05.

RESULTS

There were 28 cases of shoulder PJI in 27 patients (age, 66.4 ± 11.2 years,); of these, 21 shoulders were revised to RTSA, and 7 shoulders were revised to hemiarthroplasty. There was no recurrent infection at a mean 32-month follow-up. One year after surgery, mean forward flexion was 110° ± 41° and abduction was 106° ± 42°. Mean final American Shoulder and Elbow Surgeons subjective score was 66.5 ± 23.3. The 21 shoulders with PJI revised to RTSA had no differences for functional and subjective outcomes compared with revised patients without shoulder PJI.

CONCLUSIONS

A 3-stage revision protocol for shoulder PJI reliably eradicated infection. Patients with PJI revised to RTSA can have similar outcomes as patients with noninfectious revision to RTSA.

Management of periprosthetic shoulder infections with the use of a permanent articulating antibiotic spacer

INTRODUCTION

Management of periprosthetic shoulder infections (PSIs) still remains challenging. We conducted a retrospective case study to assess the outcomes of definitive articulating antibiotic spacer implantation in a cohort of elderly, low-demanding patients. We hypothesized that in patients with low functional demands seeking pain relief with chronic PSIs, treatment with a definitive articulating antibiotic spacer would lead to satisfying results concerning eradication of the infection, improvement of pain, and improving shoulder function.

MATERIALS AND METHODS

19 patients underwent definitive articulating antibiotic spacer implantation for the treatment of an infected shoulder arthroplasty. Mean age at surgery was 70.2 years. Patients were assessed pre-operatively with functional assessment including Constant-Murley score, and objective examination comprehending ROM, visual analog scale pain score, and patient subjective satisfaction (excellent, good, satisfied, or unsatisfied) score. Radiographs were taken to examine signs of loosening, and change in implant positioning.

RESULTS

At the most recent follow-up, none of the patients had clinical or radiographic signs suggesting recurrent infection. Most patients reported satisfying subjective and objective outcomes. Follow-up examination showed significant improvement of all variables compared to pre-operative values (p < 0.001). Radiographs did not show progressive radiolucent lines or change in the position of the functional spacer. In one case, glenoid osteolysis was reported, which did not affect the clinical outcome.

CONCLUSIONS

In selected elderly patients with low functional demands seeking pain relief with infected shoulder arthroplasty, definitive management with a cement spacer is a viable treatment option that helps in eradicating shoulder infection and brings satisfying subjective and objective outcomes.

LEVEL OF EVIDENCE

Case series, Level IV.

Results of cement spacer sonication in the second stage of two-stage treatment of shoulder arthroplasty infection

Background

The objective of this study is to present the results of cement spacer sonication in the second stage of two-stage treatment of shoulder arthroplasty infection and to determine the rate of positive cultures in the second-stage surgery in shoulder arthroplasty and its meaning.

Methods

Twenty-one patients (22 cement spacers) treated with two-stage surgery because of a shoulder arthroplasty infection were included. In the second stage, the cement spacer was sent for sonication and at least four tissue cultures were obtained. Epidemiological data, comorbidities, sensitivity of the microorganisms to the antibiotic loaded in the cement spacer in the first revision surgery, time elapsed since an antibiotic was last administered until second revision procedure, functional shoulder status at last follow-up, and any complication were recorded.

Results

Three out of the 22 cases (13.6%) presented positive cultures at the second-stage surgery. Periprosthetic tissue culturing detected the three positive culture cases in the second stage while the cement spacer sonication detected two and missed one. Considering periprosthetic tissue culturing as the standard procedure, the cement spacer sonication showed sensitivity at 66.6%. Recurrent infection over time was considered present in 3 patients; two of them had been previously diagnosed with a positive culture at the second stage (66.6%).

Conclusions

A good number of patients (13.6%) present a positive culture at the second stage of the two-stage surgical procedure for infected shoulder arthroplasty, and those patients seem to be at high risk for recurrent infection. Periprosthetic tissue cultures have a higher sensitivity to detecting a positive culture at the second stage than cement spacer sonication.

Two-stage reimplantation for the treatment of deep infection after shoulder arthroplasty

BACKGROUND

Two-stage reimplantation is the most common treatment modality considered for periprosthetic shoulder infection (PSI). Most studies to date have reported on a relatively small number of shoulders. The purpose of this study was to determine the outcome of 2-stage reimplantation for PSI in terms of both eradication of infection and restoration of function.

METHODS

Between 1980 and 2010, 40 shoulders (39 patients) underwent a 2-stage reimplantation for PSI; 35 shoulders (34 patients) met inclusion criteria (10 hemiarthroplasties, 24 anatomic total shoulder arthroplasties, 1 reverse total shoulder arthroplasty). Outcome data included pain, motion, Neer rating, and complications.

RESULTS

At most recent follow-up (4.1 years), 2-stage reimplantation had resulted in significant improvements in pain (from 4.4 to 2 on a 5-point scale; P < .0001), mean forward elevation (64°-118°; P < .0001), and mean external rotation (14°-41°; P < .0001). Preoperative testing showed leukocytosis in 1 patient, elevated C-reactive protein concentration in 67%, elevated erythrocyte sedimentation rate in 61%, and positive preoperative aspiration in 69%. Persistent infection, defined as positive cultures in samples obtained at the time of reimplantation, was identified in 5 shoulders (15%); 50% of persistent infections grew Propionibacterium acnes. Reoperations for infection included irrigation and débridement (1), a second 2-stage reimplantation (2), and resection arthroplasty (1); 2 additional patients were treated with chronic suppression. Reoperation for aseptic glenoid loosening was performed in 2 additional shoulders. Results were graded excellent in 10 (28%), satisfactory in 12 (33%), and unsatisfactory in 13 (39%) shoulders.

CONCLUSION

Two-stage reimplantation eradicated PSI in 85% of the shoulders. Pain relief and good arcs of motion were achieved in many patients, but there was an overall rate of unsatisfactory results approaching 40%. Preoperative testing was not always reliable for the diagnosis of PSI.

Two-stage revision for infected shoulder arthroplasty

BACKGROUND

Periprosthetic shoulder infections (PSIs) are challenging to treat and often result in significant patient morbidity. Without a standardized treatment protocol, PSIs are often managed similarly to periprosthetic hip and knee infections. Because 2-stage revision is the gold standard for treating periprosthetic hip and knee infections, we performed a case series and literature review to determine its effectiveness in PSIs.

METHODS

We identified 19 patients (14 men) from our institution who were treated with a 2-stage revision after presenting with a PSI. Mean patient age was 63 ± 9 years, and average body mass index was 30.8 ± 5.8. The average time from the index arthroplasty to treatment was 40 months, 8 of 13 positive cultures were Propionibacterium acnes, and 9 of 19 patients had multiple shoulder operations before presenting with infection. Minimum follow-up for all patients was 2 years.

RESULTS

After a mean follow-up of 63 months (range, 25-184 months), 15 of 19 patients in our study were successfully treated for PSI. Average postoperative American Shoulder and Elbow Surgeons (ASES) Shoulder Assessment score was 69 (range, 32-98) and average postoperative forward elevation was significantly increased from 58° to 119° (P < .001). The incidence of recurrent infection was 26%. The rate of noninfection complications was 16%, for a total complication rate of 42%.

CONCLUSION

In patients with PSIs, especially those with intractable, chronic infections, a 2-stage revision represents a viable treatment option for eradicating infection and restoring function. However, it is important to recognize the risk of recurrent infection and postoperative complications in this challenging patient population.

Periprosthetic shoulder infection: an overview

Periprosthetic shoulder infection (PSI) is rare but potentially devastating. The rate of PSI is increased in cases of revision procedures, reverse shoulder implants and co-morbidities. One specific type of PSI is the occurrence of low-grade infections caused by non-suppurative bacteria such as Propionibacterium acnes or Staphylococcus epidemermidis.

Success of treatment depends on micro-organism identification, appropriate surgical procedures and antibiotic administration efficiency. Post-operative early PSI can be treated with simple debridement, while chronic PSI requires a one- or two-stage revision procedure. Indication for one-time exchange is based on pre-operative identification of a causative agent. Resection arthroplasty remains an option for low-demand patients or recalcitrant infection.

Cite this article: EFORT Open Rev 2017;2:104-109. DOI: 10.1302/2058-5241.2.160023

Clinical impact of positive Propionibacterium acnes cultures in orthopedic surgery

BACKGROUND

The clinical significance of a positive culture to Propionibacterium acnes in orthopedic specimens remains unclear, whether about its role as a contaminant or a pathogen, or its impact as a coinfectant. Therefore, we performed a retrospective study to provide a more accurate description of the clinical impact of P. acnes in an orthopedic population aiming to determine: 1) if there is a clinical difference between P. acnes infection and contamination? 2) If there is a clinical difference between P. acnes monoinfection, and coinfection.

HYPOTHESIS

There is a clinical difference between P. acnes infection and contamination.

MATERIALS AND METHODS

Patients were selected over a five-year period, and those with a minimum of one positive culture for P. acnes, from any intraoperative orthopedic tissue sample, were included in the study. P. acnes infection was defined as the isolation of P. acnes from≥2 specimens, or in only one specimen, in the presence of typical perioperative findings and/or local signs of infection.

RESULTS

A total of 68 patients had a positive P. acnes culture, 35 of which were considered to be infected. The infections affected mostly males (29/35-83%), occurred mostly in shoulders (22/35-63%), and at a site already containing an orthopedic implant (32/35-91%). Local inflammatory signs were present in half of the cases when an infection was diagnosed. Coinfection with other pathogens was present in 31% of patients (11/35). When comparing patients coinfected with P. acnes, and those who were monoinfected, the latter presented less often with local inflammatory signs. Recurrence rate was 24% (8/35) and the only risk factor for recurrence was the presence of a monoinfection.

DISCUSSION

This study confirms the pathogenicity of P. acnes in an orthopedic population, as it is present in multiple samples in the same patient, and because it is present in cultures from cases with clinical recurrence. Our study showed that monoinfections differ from coinfections mainly by their higher risk of recurrence.

LEVEL OF EVIDENCE

Level IV retrospective case series.

Utility of prerevision tissue biopsy sample to predict revision shoulder arthroplasty culture results in at-risk patients

BACKGROUND

The diagnosis of infection after shoulder arthroplasty can be challenging. The current study evaluated the utility of a prerevision biopsy sample in predicting positive cultures or a final diagnosis of infection in the setting of an "at-risk" failed shoulder arthroplasty.

METHODS

The study reviewed 77 patients with no history of infection undergoing revision shoulder arthroplasty by a single surgeon between June 2010 and July 2015. All patients with a C-reactive protein and erythrocyte sedimentation rate within normal reference ranges and no fluid on aspirate, or an abnormal value for the erythrocyte sedimentation rate or C-reactive protein, or both, and no growth on aspirate, underwent a prerevision biopsy because they were considered "at-risk" for infection. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated to evaluate the utility of biopsy specimens to predict positive cultures as well as a final determination of infection.

RESULTS

A prerevision biopsy was performed in 17 patients with a failed arthroplasty. The sensitivity, specificity, PPV, and NPV, for a positive prerevision biopsy sample to predict a positive final culture were 0.75, 0.6, 0.82, and 0.5, respectively. The sensitivity, specificity, PPV, and NPV for an infection defined by a prerevision biopsy sample to predict an infection defined by the combined final revision and biopsy cultures were 0.9, 0.86, 0.9, and 0.86, respectively.

CONCLUSIONS

The ability for prerevision biopsy specimens of failed arthroplasties to predict the presence of bacteria at the time of revision surgery is high, although lower than previously reported. If biopsy results are used to define and predict a diagnosis of infection, the sensitivity, specificity, PPV, and NPV all significantly improve.

Single-Stage Revision Is Effective for Failed Shoulder Arthroplasty with Positive Cultures for Propionibacterium

BACKGROUND

Revision shoulder arthroplasties are often culture-positive for Propionibacterium. This study tests the hypothesis that the functional outcomes of revising Propionibacterium culture-positive failed arthroplasties with a single-stage revision and immediate antibiotic therapy are not inferior to the clinical outcomes of revising failed shoulder arthroplasties that are not culture-positive.

METHODS

Fifty-five shoulders without obvious clinical evidence of infection had a single-stage revision arthroplasty. The patient self-assessed functional outcomes for shoulders with ≥2 positive cultures for Propionibacterium (the culture-positive group) were compared with shoulders with no positive cultures or only 1 positive culture (the control group).

RESULTS

The culture-positive group had 89% male patients, with a mean age (and standard deviation) of 63.5 ± 7.2 years. The mean Simple Shoulder Test (SST) scores for the 27 culture-positive shoulders improved from 3.2 ± 2.8 points before the surgical procedure to 7.8 ± 3.3 points at a mean follow-up of 45.8 ± 11.7 months after the surgical procedure (p < 0.001), a mean improvement of 49% of the maximum possible improvement. The control group had 39% male patients, with a mean age of 67.1 ± 8.1 years. The mean SST scores for the 28 control shoulders improved from 2.6 ± 1.9 points preoperatively to 6.1 ± 3.4 points postoperatively at a mean follow-up of 49.6 ± 11.8 months (p < 0.001), a mean improvement of 37% of the maximum possible improvement. Subsequent procedures for persistent pain or stiffness were required in 3 patients (11%) in the culture-positive group and in 3 patients (11%) in the control group; none of the revisions were culture-positive. Fourteen patients reported side effects to antibiotics.

CONCLUSIONS

Clinical outcomes after single-stage revision for Propionibacterium culture-positive shoulders were at least as good as the outcomes in revision procedures for control shoulders. Two-stage revision procedures may not be necessary in the management of these cases. Patients should be educated with regard to potential antibiotic side effects.

LEVEL OF EVIDENCE

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

Definitive Treatment of Infected Shoulder Arthroplasty With a Cement Spacer

Infection in the setting of shoulder arthroplasty can result in significant pain, loss of function, and the need for additional surgery. As the use of shoulder arthroplasty increases, the medical and economic burdens of periprosthetic joint infection increase as well. The ideal management of infected shoulder prostheses has not been established. This report describes 9 patients from a single institution who had an infected shoulder arthroplasty that was definitively managed with a cement spacer. All patients had a minimum of 2 years of follow-up. Of the 9 patients in this study, 6 were men. Mean age was 73±9 years. Of the study patients, 1 had diabetes, 2 presented with Parkinson's disease, and 5 had a history of tobacco use. Average body mass index was 27.9±7 kg/m(2). After mean follow-up of 4 years, none of the patients had clinical or radiographic evidence of infection. Functional outcomes, as measured by American Shoulder and Elbow Surgeons scores, were good or fair in 89% of patients, and the average American Shoulder and Elbow Surgeons score was 57. A review of recent literature suggested that the current findings were similar to those in studies reporting 1- or 2-stage revision procedures. Although cement spacers are typically used as part of a 2-stage revision procedure, the current findings suggest that cement spacers can be used effectively to eradicate infection and allow for acceptable functional recovery and range of motion in patients who have severe medical comorbidities and cannot tolerate additional surgery. [Orthopedics. 2016; 39(5):e924-e930.].

Propionibacterium in Shoulder Arthroplasty: What We Think We Know Today

➤ Propionibacterium is a slow-growing gram-positive rod that is part of the normal skin microbiome but can be found on culture of specimens from a large number of patients having revision shoulder arthroplasty performed for pain, stiffness, and component loosening. ➤ Propionibacterium infections do not present with obvious signs of infection, such as swelling, erythema, drainage, or tenderness, but rather are of the so-called stealth type, presenting with unexplained pain, stiffness, or component loosening months to years after the index arthroplasty. ➤ Not all propionibacteria are the same: certain subtypes of Propionibacterium are enriched with virulence factors that may enhance deep infection. ➤ Because propionibacteria typically reside in the pilosebaceous glands of the oily skin of the chest and back, standard surgical skin preparation solutions and even perioperative intravenous antibiotics are often inadequate at sterilizing the incision site; therefore, other prophylactic measures such as meticulous implant handling to avoid contact with dermal structures need to be considered. ➤ Recovery of Propionibacterium from the surgical wounds requires that multiple specimens for culture be taken from different areas of the shoulder to reduce sampling error, and cultures should be held for two weeks on multiple culture media. ➤ Future research efforts can be focused on reducing the risk of implant infection and point-of-care methods for identifying Propionibacterium infections.

Two-stage revision arthroplasty for periprosthetic joint infections: What is the value of cultures and white cell count in synovial fluid and CRP in serum before second stage reimplantation?

INTRODUCTION

Besides CRP in serum, white cell counts and cultures of synovial fluid are routinely used to detect periprosthetic joint infections. But the sensitivities of these parameters do vary from 12 to 100 %. In two stage revision arthroplasty before the second stage surgeons have to decide if reimplantation is justified. Therefore, we investigated the value of cultures and white cell count from the synovial fluid with a polymethyl methacrylate spacer in place and CRP in serum before reimplantation to detect persistent infection in a standardized setting.

METHODS

115 patients with a two-stage revision hip or knee arthroplasty were included in this study. All patients had an antibiotic loaded polymethylmethacrylate spacer. Retrospectively synovial cultures, white blood count in synovial fluid and CRP in serum were assessed before reimplantation.

RESULTS

The sensitivity of the synovial cultures was 5 % (95 % CI 0.13-24.87), with a specificity of 99 % (95 % CI 94.27-99.97). For white blood count in synovial fluid the sensitivity was 31.3 %, specificity was 39.1 %. Sensitivity for CRP in serum was 42.10 %, specificity was 84.21 %.

CONCLUSION

Cultures from synovial fluid and white blood count in synovial fluid and CRP seem to be uncertain parameters to exclude persistent infection. We do not recommend joint aspiration before reimplantation anymore. Further research is necessary to find other markers to confirm or exclude persistent infection.

Management of complications after reverse shoulder arthroplasty

Reverse total shoulder arthroplasty (RTSA) has become the treatment of choice for patients with rotator cuff arthropathy. Complication rate after RTSA has been reported to be three to five times that of conventional total shoulder arthroplasty. Intraoperative and postoperative complications include neurological injury, infection, dislocation or instability, acromial or scapular spine fracture, hematoma, and scapular notching. Knowledge of optimal component placement along with preoperative planning and recognition of risk factors are essential in optimizing patient outcome. The purpose of this review article is to identify the most common and serious complications associated with the RTSA and discuss the current methods of management. Complications after RTSA pose a significant challenge for healthcare providers and economic burden to society. Therefore, it is essential to make the proper diagnosis and develop and implement early management plans to improve patient outcome and satisfaction.

Management of Propionibacterium acnes infection after shoulder surgery

Propionibacterium acnes (P. acnes) is a gram-positive anaerobic bacillus commonly isolated from the flora of the face, chest, and axilla region. It has emerged as a major pathogen responsible for postoperative shoulder infections after both arthroscopy and arthroplasty procedures. Patients with P. acnes shoulder infection typically present with normal laboratory values (white blood cells (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP)) making diagnosis difficult. Several intraoperative tissue cultures should be obtained and cultured in both agar plate and broth in aerobic and anaerobic conditions for a minimum of 13 days to optimize the sensitivity and specificity to detect P. acnes. The utilization of intraoperative frozen sections to detect P. acnes infection is not reliable. Risk factors include male, cloudy synovial fluid, lucencies around the implant, and periprosthetic membrane formation. Managements include irrigation and debridement, single or two-staged revision, and intravenous antibiotics. Open biopsy prior to the final implantation (two-staged revision) may help detect persistent P. acnes infection. Penicillin and cephalosporins are effective against clinical P. acnes infection and biofilm in vitro. Combination antibiotic therapy with rifampin and daptomycin may further increase the clinical efficacy of treatment.

Management of complications after revision shoulder arthroplasty

Complications after revision shoulder arthroplasty are similar to those in the primary setting which include instability, fracture, bone loss, infection, nerve injury, and loosening. Unlike in the primary setting, however, the rate of complications for revisions is significantly greater and the management is more complex because of overlapping complications and limited treatment options. Furthermore, there is a paucity of evidence-based literature to direct the management options in these patients. The purposes of this review are to broadly outline the major complications that are seen in revision shoulder arthroplasty and to provide general principles on how to recognize and approach these complex cases.