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

Periprosthetic Joint Infection: What's New?

Total joint arthroplasty (TJA) ranks among the most commonly performed orthopedic surgeries, with its annual incidence on the rise globally. Periprosthetic joint infection (PJI) remains a leading cause of arthroplasty failure. This review aims to summarize recent literature updates on the epidemiology, diagnosis, and management of PJI.

Outcomes following revision reverse shoulder arthroplasty for infection

BACKGROUND

In comparison to primary reverse shoulder arthroplasty (RSA) procedures, revision arthroplasty can be a longer and more complex procedure leading to an increased risk of complications. The reported rates of infection in primary RSA range from 1% to 19% and the cost impact on patients and health care systems is significant, leading to multiple revision surgeries. The purpose of this study was to evaluate the postoperative outcomes, complications, and revision rates for revision reverse shoulder arthroplasty (rRSA) due to infection compared with rRSA for noninfectious causes.

METHODS

Patients who underwent rRSA between 2009 and 2020 by a single fellowship-trained orthopedic surgeon at a single institution were retrospectively identified through a prospectively collected database. Patients were separated into 2 cohorts based on revision diagnosis: (1) rRSA due to infection (rRSAi) and (2) rRSA due to noninfectious causes (rRSAn). Patient-reported outcome scores (PROs), including the Simple Shoulder Test, Constant score, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score, University of California-Los Angeles shoulder score, Shoulder Arthroplasty Smart score, and active range of motion (ROM) were collected preoperatively and at a minimum 1-year follow-up. Postoperative complications and revision rates were also collected.

RESULTS

A total of 93 patients (n = 19 rRSAi group, n = 74 rRSAn group) with a mean age of 68 years were included in this analysis. All baseline demographics were comparable between groups. No significant differences were found in preoperative or postoperative PROs and ROM between the 2 groups. Postoperative complication rates and revision rates were comparable between the groups.

CONCLUSION

RSA due to infection results in similar patient-reported outcome scores, range of motion, and revision rates when compared to rRSA for noninfectious causes. Our results suggest that despite the unique challenges associated with rRSA for infection, patient outcomes do not differ from cases attributed to noninfectious causes. More efforts are warranted to further validate and contextualize these findings, considering the protentional influence of patient-specific and implant-specific factors.

Preventing Infections in Reverse Shoulder Arthroplasty

PURPOSE OF REVIEW

Reverse shoulder arthroplasty (rTSA) is a commonly performed procedure to treat degenerative conditions of the shoulder. With its growing utilization, techniques to reliably diagnose and treat prosthetic joint infection (PJI) have become increasingly important. In this review we outline the current research and prevention methods of prosthetic joint infection in rTSA. This includes preoperative considerations, intraoperative, and postoperative treatment algorithms.

RECENT FINDINGS

There is currently no established standardized protocol for preoperative infection prevention or post operative management. However, recent studies have identified risk factors for infection, as well as successful prevention techniques that can be implemented to minimize infection risk. Although there is no standardized protocol currently utilized to diagnose and treat shoulder PJI, we outline a potential set of preventative measures and postoperative management strategies that clinicians can use to properly diagnose and treat patients with this difficult condition.

Fungal Shoulder Periprosthetic Infections: A Systematic Review

Background: Data regarding fungal PJIs of the shoulder are scarce. The present systematic review aims to identify and evaluate all published shoulder fungal PJIs in an effort to better understand the diagnostic and therapeutic approach to these infections. Methods: A systematic review according to the PRISMA guidelines was conducted, locating all shoulder fungal PJIs. The initial search located 1435 articles. Data were collected on demographics, the causative fungus, antifungal treatment (AFT), surgical interventions, and infection outcomes. Results: After screening and implementation of the inclusion criteria, a total of 10 articles, including 10 cases, were eligible. The sample's mean age was 62.44 years. Diabetes mellitus was the most common comorbidity (30%), while 70% were immunocompromised. Candida spp. was the most common causative fungus (nine cases; 90%), while all cases were confirmed with cultures. In three cases (30%), there was bacterial co-infection. The mean duration of antifungal treatment (AFT) was 8.4 weeks, while the preferred agent was fluconazole (60% of cases), followed by amphotericin B (30%). Most cases (50%) underwent resection arthroplasty as part of the treatment, while two-stage revision arthroplasty was performed in 30%. Infection's eradication was reported in 90% of the studied cases. Conclusions: The diagnosis and management of fungal periprosthetic shoulder infections are particularly challenging and require a multidisciplinary approach. The combination of antifungal therapy and tailored surgical strategies is crucial, but further research is needed to refine treatment protocols and address the unique considerations in shoulder PJIs.

Single-stage revision for total shoulder arthroplasty infection. Results at a minimum 2 years follow-up

INTRODUCTION

Similar to the management of periprosthetic joint infections of the lower limb, one-stage revision in total shoulder arthroplasty (TSA) infections is an option that has been highlighted in scientific publications since the early 2010s. However, there are only a few studies which validate this treatment and determine its scope of application in relation to two-stage treatment.

HYPOTHESIS

Single-stage revision for infected TSA is a reliable treatment allowing good infection control and satisfactory functional results.

METHODS

This single-center retrospective series of 34 consecutive patients operated on between 2014 and 2020 for a one-stage prosthetic revision was evaluated at a minimum of 2 years of follow-up. All of the patients included underwent revision shoulder arthroplasty during this period with the diagnosis of infection confirmed by microbiological analysis of surgical samples. Patients who did not benefit from a bipolar revision were excluded. All patients were followed at least 2 years after the intervention. Clinically suspected recurrence of infection was confirmed by a periprosthetic sample under radiographic guidance. Functional clinical outcomes as well as mechanical complications were also reported.

RESULTS

The average follow-up was 40.4 months (24-102±21.6). A septic recurrence was observed in three patients (8.8%). A mechanical complication was present in four patients (14.7%), and three (11.8%) required at least one surgical revision. The mean Constant-Murley score at the last follow-up was 49 (42-57±21.83).

DISCUSSION

Single-stage revision for shoulder periprosthetic joint infection results in a success rate of 91.2% with satisfactory functional results after more than 2 years of follow-up.

LEVEL OF EVIDENCE

IV; retrospective study.

Humeral stem loosening is not always prosthetic joint infection

BACKGROUND

Aseptic humeral stem loosening is an uncommon complication of shoulder arthroplasty, and its presence has been considered a highly specific predictor of prosthetic joint infection (PJI). Literature on aseptic humeral stem loosening is sparse. The primary purpose of this study was to determine the rate of aseptic humeral loosening in revision shoulder arthroplasty. Secondarily, we sought to identify predictors of septic and aseptic humeral loosening.

METHODS

Our institutional revision shoulder arthroplasty database was reviewed. Inclusion criteria were patients with humeral stem loosening as indicated in the operative report. Patient demographics, index surgery and indication, revision surgery and indication, and operative data were recorded. Charts were manually reviewed, and PJI scores were calculated using the International Consensus Meeting scoring criteria. International Consensus Meeting classifications of PJI "unlikely" and "possible" were considered aseptic, and PJI "probable" and "definite" were considered septic. Statistical analysis was performed to determine associations between the abovementioned variables and aseptic humeral loosening.

RESULTS

Forty-six patients with 48 shoulders were included in our analysis. Ten cases (21%) were classified as definite PJI, 13 cases (27%) were classified as probable PJI, 4 cases (8%) were classified as possible PJI, and 21 cases (44%) were classified as PJI unlikely. On analysis of stem design, there were no statistically significant associations with aseptic loosening; although, a lack of proximal porous ingrowth surface trended toward higher rates of aseptic loosening in all patients and in anatomic total shoulder arthroplasty (ATSA) and reverse total shoulder arthroplasty (RTSA) subgroup analyses. In the index RTSA subgroup, aseptic loosening was associated with female sex (P = .005). Seventeen of 39 shoulders (44%) that underwent either index ATSA or RTSA demonstrated concomitant glenoid loosening. The absence of glenoid loosening was associated with aseptic humeral loosening in index ATSA and RTSA (P < .001).

CONCLUSION

Fifty-two % of revision shoulder arthroplasty cases with humeral loosening performed at our institution were aseptic. There appear to be distinct demographic and radiographic factors that are more commonly associated with aseptic as opposed to septic humeral loosening. Our data demonstrate that demographic predictors of aseptic loosening of RTSA include female sex. The absence of glenoid component loosening is associated with aseptic humeral loosening and concomitant glenoid loosening is associated with septic humeral loosening. Understanding of these factors can guide the preoperative index of suspicion for PJI in the setting of humeral stem loosening.

Factors affecting risk of recurrence with periprosthetic infection in shoulder arthroplasty

BACKGROUND

The goal of treating periprosthetic infection, besides its eradication, is to avoid recurrence. The purpose of this study was to evaluate the impact of increasing Infection Severity (IS) score (based on the 2018 International Consensus Meeting on Orthopedic Infections statement), single-stage revision, and pathogenicity of the infective organism on the risk of infection recurrence.

METHODS

A database of 790 revisions performed by a single surgeon from 2004-2020 was reviewed for patients with minimum 2-year follow-up and ≥1 positive culture finding and/or pathology result from the revision surgical procedure. In total, 157 cases performed in 144 patients met the inclusion criteria. These cases were then categorized by infection probability (IS score) according to the 2018 consensus statement. Of 157 cases, 46 (29%) were classified as definitely or probably infected; 25 (16%), possibly infected; and 86 (55%), unlikely to be infected. Additionally, patients were grouped by single-stage surgery and pathogenicity of the infective organism.

RESULTS

A recurrence in this study was classified as the growth of the same organism in any patient requiring revision surgery. The 86 cases in the group with unlikely infection showed a recurrence rate of 2.3%. The 25 cases in the group with possible infection showed a recurrence rate of 12%. The 46 cases in the group with definite or probable infection showed a recurrence rate of 17.4%. Patients in the definite/probable infection group had a higher rate of recurrence than those in the groups with possible infection and unlikely infection (P = .009). The IS score was higher in the recurrence group than the non-recurrence group (7.5 ± 4.3 vs. 3.9 ± 3.4, P < .001). Overall, patients who underwent 1-stage revision had a 5.0% recurrence rate, but among the 34 patients with an infection classification of definite or probable who underwent 1-stage revision, the recurrence rate was 5.9%. Cases of highly virulent methicillin-resistant Staphylococcus aureus also showed a recurrence rate of 30.8% compared with 4.0% and 5.9% for Cutibacterium acnes and coagulase-negative staphylococci, respectively (P = .005).

CONCLUSION

Recurrent infection after treatment of a periprosthetic infection is associated with increasing severity scores, as defined in the 2018 consensus statement, and more aggressive microorganisms. However, a single-stage surgical procedure, even in patients with higher IS scores, did not impart a significantly increased risk of recurrence.

Efficacy of a Novel Intraoperative Surgical Irrigant in Preventing Periprosthetic Joint Infections in Primary Knee, Hip, and Shoulder Arthroplasties: A Retrospective Analysis

OBJECTIVE

Primary joint arthroplasty (JA) is one of the most common operating room (OR) procedures, with knee and hip arthroplasties being listed in the top five most frequent OR procedures and while not as common, shoulder arthroplasties are increasing at greater rates than knee and hip arthroplasties. Periprosthetic joint/shoulder infections (PJI/PSI) are a devastating complication of primary JAs with infection prevention deemed as the single most important strategy in combating them. The objective of this study was to retrospectively evaluate the efficacy of XPERIENCE® Advanced Surgical Irrigation (XP) in preventing PJI following primary joint arthroplasty.

METHODS

This is a retrospective study of primary knee, hip and shoulder arthroplasties that were performed by multiple orthopedic surgeons at a single hospital setting. XPERIENCE was used as an intraoperative surgical irrigant either solely, or with other intraoperative practices for prevention of infection. Incidence of acute PJI occurring within 90 days of index surgery were retrospectively collated.

RESULTS

Four hundred and twenty-three (423) primary joint replacement surgeries treated intraoperatively with XP, were evaluated for acute PJI incidence. Retrospective evaluations determined that 95% of the subjects had at least one risk factor predisposing them to PJI. There were zero PJIs diagnosed in the knee and hip arthroplasty cohorts and zero PSIs diagnosed in the shoulder arthroplasty cohorts.

CONCLUSION

The absence of PJI/PSI diagnoses in the JA cohorts treated intraoperatively with XP indicates that it could be an efficacious antimicrobial irrigant in preventing PJI, and warrants being evaluated in prospective, randomized controlled clinical trials as the sole intraoperative irrigant, as well as in combination with the other intraoperative infection prevention regimens evaluated in this retrospective study.

After primary shoulder arthroplasty appropriate vancomycin antibiotic prophylaxis does not lead to increased infectious complications when compared to cefazolin

BACKGROUND

In primary shoulder arthroplasty (SA), intravenous (IV) cefazolin has demonstrated lower rates of infectious complications when compared to IV vancomycin. However, previous analyses included SA cohorts with both complete and incomplete vancomycin administration. Therefore, it is currently unclear whether cefazolin still maintains a prophylactic advantage to vancomycin when it is appropriately indicated and sufficiently administered at the time of surgical incision. This study evaluated the comparative efficacy of cefazolin and complete vancomycin administration for surgical prophylaxis in primary shoulder arthroplasty with respect to infectious complications.

METHODS

A retrospective cohort study was conducted utilizing a single institution total joint registry database, where all primary SA types (hemiarthroplasty, anatomic total shoulder arthroplasty, and reverse shoulder arthroplasty) performed between 2000 to 2019 for elective and trauma indications using IV cefazolin or complete vancomycin administration as the primary antibiotic prophylaxis were identified. Vancomycin was primarily indicated for patients with a severe self-reported penicillin or cephalosporin allergy and/or MRSA colonization. Complete administration was defined as at least 30 minutes of antibiotic infusion prior to incision. All included SA had at least 2 years of clinical follow-up. Multivariable Cox proportional hazard regression was used to evaluate all-cause infectious complications including survival free of prosthetic joint infection (PJI).

RESULTS

The final cohort included 7177 primary SA, 6879 (95.8%) received IV cefazolin and 298 (4.2%) received complete vancomycin administration. Infectious complications occurred in 120 (1.7%) SA leading to 81 (1.1%) infectious reoperations. Of the infectious complications, 41 (0.6%) were superficial infections and 79 were (1.1%) PJIs. When categorized by administered antibiotics, there were no differences in rates of all infectious complications (1.6% vs. 2.3%; P = .352), superficial complications (0.5% vs. 1.3%; P = .071), PJI (1.1% vs. 1.0%; P = .874), or infectious reoperations (1.1% vs. 1.0%; P = .839). On multivariable analyses, complete vancomycin infusion demonstrated no difference in rates of infectious complications compared to cefazolin administration (hazard ratio [HR], 1.50 [95% confidence interval (CI), 0.70 to 3.25]; P = .297), even when other independent predictors of PJI (male sex, prior surgery, and Methicillin-resistant Staphylococcus aureus colonization) were considered.

CONCLUSIONS

In comparison to cefazolin, complete administration of vancomycin (infusion to incision time greater than 30 minutes) as the primary prophylactic agent does not adversely increase the rates of infectious complications and PJI. Prophylaxis protocols should promote appropriate indications for the use of cefazolin or vancomycin, and when necessary, ensure complete administration of vancomycin to mitigate additional infectious risks after primary SA.

Posterior Shoulder Instability, Part I-Diagnosis, Nonoperative Management, and Labral Repair for Posterior Shoulder Instability-An International Expert Delphi Consensus Statement

PURPOSE

To establish consensus statements on the diagnosis, nonoperative management, and labral repair for posterior shoulder instability.

METHODS

A consensus process on the treatment of posterior shoulder instability was conducted, with 71 shoulder/sports surgeons from 12 countries participating on the basis of their level of expertise in the field. Experts were assigned to 1 of 6 working groups defined by specific subtopics within posterior shoulder instability. Consensus was defined as achieving 80% to 89% agreement, whereas strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement.

RESULTS

Unanimous agreement was reached on the indications for nonoperative management and labral repair, which include whether patients had primary or recurrent instability, with symptoms/functional limitations, and whether there was other underlying pathology, or patient's preference to avoid or delay surgery. In addition, there was unanimous agreement that recurrence rates can be diminished by attention to detail, appropriate indication and assessment of risk factors, recognition of abnormalities in glenohumeral morphology, careful capsulolabral debridement and reattachment, small anchors with inferior placement and multiple fixation points that create a bumper with the labrum, treatment of concomitant pathologies, and a well-defined rehabilitation protocol with strict postoperative immobilization.

CONCLUSIONS

The study group achieved strong or unanimous consensus on 63% of statements related to the diagnosis, nonoperative treatment, and labrum repair for posterior shoulder instability. The statements that achieved unanimous consensus were the relative indications for nonoperative management, and the relative indications for labral repair, as well as the steps to minimize complications for labral repair. There was no consensus on whether an arthrogram is needed when performing advanced imaging, the role of corticosteroids/orthobiologics in nonoperative management, whether a posteroinferior portal is required.

LEVEL OF EVIDENCE

Level V, expert opinion.

Posterior Shoulder Instability, Part II-Glenoid Bone Grafting, Glenoid Osteotomy, and Rehabilitation/Return to Play-An International Expert Delphi Consensus Statement

PURPOSE

To establish consensus statements on glenoid bone grafting, glenoid osteotomy, rehabilitation, return to play, and follow-up for posterior shoulder instability.

METHODS

A consensus process on the treatment of posterior shoulder instability was conducted, with 71 shoulder/sports surgeons from 12 countries participating on the basis of their level of expertise in the field. Experts were assigned to 1 of 6 working groups defined by specific subtopics within posterior shoulder instability. Consensus was defined as achieving 80% to 89% agreement, whereas strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement.

RESULTS

All of the statements relating to rehabilitation, return to play, and follow-up achieved consensus. There was unanimous consensus that the following criteria should be considered: restoration of strength, range of motion, proprioception, and sport-specific skills, with a lack of symptoms. There is no minimum time point required to return to play. Collision athletes and military athletes may take longer to return because of their greater risk for recurrent instability, and more caution should be exercised in clearing them to return to play, with elite athletes potentially having different considerations in returning to play. The relative indications for revision surgery are symptomatic apprehension, multiple recurrent instability episodes, further intra-articular pathologies, hardware failure, and pain.

CONCLUSIONS

The study group achieved strong or unanimous consensus on 59% of statements. Unanimous consensus was reached regarding the criteria for return to play, collision/elite athletes having different considerations in return to play, indications for revision surgery, and imaging only required as routine for those with glenoid bone grafting/osteotomies at subsequent follow-ups. There was no consensus on optimal fixation method for a glenoid bone block, the relative indications for glenoid osteotomy, whether fluoroscopy is required or if the labrum should be concomitantly repaired.

LEVEL OF EVIDENCE

Level V, expert opinion.

European Society for Surgery of the Shoulder and Elbow (SECEC) rotator cuff tear registry Delphi consensus

Background

The purpose of this study was to establish consensus statements via a Delphi process on the factors that should be included in a registry for those patients undergoing rotator cuff tear treatment.

Methods

A consensus process on the treatment of rotator cuff utilizing a modified Delphi technique was conducted. Fifty-seven surgeons completed these consensus statements and 9 surgeons declined. The participants were members of the European Society for Surgery of the Shoulder and Elbow committees representing 23 European countries. Thirteen questions were generated regarding the diagnosis and follow-up of rotator cuff tears were distributed, with 3 rounds of questionnaires and final voting occurring. Consensus was defined as achieving 80%-89% agreement, whereas strong consensus was defined as 90%-99% agreement, and unanimous consensus was defined by 100% agreement with a proposed statement.

Results

Of the 13 total questions and consensus statements on rotator cuff tears, 1 achieved unanimous consensus, 6 achieved strong consensus, 5 achieved consensus, and 1 did not achieve consensus. The statement that reached unanimous consensus was that the factors in the patient history that should be evaluated and recorded in the setting of suspected/known rotator cuff tear are age, gender, comorbidities, smoking, traumatic etiology, prior treatment including physical therapy/injections, pain, sleep disturbance, sports, occupation, workmen's compensation, hand dominance, and functional limitations. The statement that did not achieve consensus was related to the role of ultrasound in the initial diagnosis of patients with rotator cuff tears.

Conclusion

Nearly all questions reached consensus among 57 European Society for Surgery of the Shoulder and Elbow members representing 23 different European countries. We encourage surgeons to use this minimum set of variables to establish rotator cuff registries and multicenter studies. By adapting and using compatible variables, data can more easily be compared and eventually merged across countries.

Diagnostic Evaluation of Prosthetic Joint Infections of the Shoulder: What Does the Literature Say?

The total number of patients with a total shoulder arthroplasty (TSA) is increasing, and the number of patients experiencing a (TSA) prosthetic joint infection (PJI) also will increase. It is important that physicians know how to identify signs of infection, know the common pathogens, and know how to work up a shoulder PJI. This publication reviewed the current literature about presenting signs and symptoms, common shoulder pathogens and how they differ from total knee and hip pathogens, and what images, tests, and procedures can aid in identification of infection.

Two-Stage Exchange Arthroplasty for Periprosthetic Reverse Shoulder Arthroplasty Infection Provides Comparable Functional Outcomes to Primary Reverse Shoulder Arthroplasty

This study aimed to compare functional outcomes after two-stage revision reverse shoulder arthroplasty (RSA) for periprosthetic joint infection (PJI) with the results of primary RSA. Patients affected by PJI and treated by means of two-stage revision RSA were 1:1 matched with a group of patients who were treated electively with RSA without developing any complications. Out of 1477 RSAs performed between 2009 and 2021, 16 patients developed a PJI. Each matched cohort comprised 16 patients (3 females, 13 males). The mean age was 69.13 ± 5.43 years old in the PJI group and 70.28 ± 5.04 (p = 0.543) in the matched cohort. The mean follow-up was 41.23 ± 26.9 months in the PJI group and 28.5 ± 20.2 (p = 0.142) in the matched group. Only one patient showed recurrent PJI five years after revision RSA. Comparison between the PJI patients and matched patients did not show any significant differences at the latest follow-up, nor for subjective shoulder value (SSV) (p = 0.101) or Constant score (p = 0.134). Two-stage exchange RSA for PJI allows for appropriate control of the disease and good functional outcomes. Comparison with an age- and sex-matched cohort of uninfected patients showed no significant differences, thus confirming the idea that revision surgeries may lead to satisfactory functional outcomes, as expected after primary surgery.

Experts Achieve Consensus on a Majority of Statements Regarding Platelet-Rich Plasma Treatments for Treatment of Musculoskeletal Pathology

PURPOSE

To establish consensus statements on platelet-rich plasma (PRP) for the treatment of musculoskeletal pathologies.

METHODS

A consensus process on the treatment of PRP using a modified Delphi technique was conducted. Thirty-five orthopaedic surgeons and sports medicine physicians participated in these consensus statements on PRP. The participants were composed of representatives of the Biologic Association, representing 9 international orthopaedic and musculoskeletal professional societies invited due to their active interest in the study of orthobiologics. Consensus was defined as achieving 80% to 89% agreement, strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement.

RESULTS

There was consensus on 62% of statements about PRP.

CONCLUSIONS

(1) PRP should be classified based on platelet count, leukocyte count, red blood count, activation method, and pure-plasma versus fibrin matrix; (2) PRP characteristics for reporting in research studies are platelet count, leukocyte count, neutrophil count, red blood cell count, total volume, the volume of injection, delivery method, and the number of injections; (3) the prognostic factors for those undergoing PRP injections are age, body mass index, severity/grade of pathology, chronicity of pathology, prior injections and response, primary diagnosis (primary vs postsurgery vs post-trauma vs psoriatic), comorbidities, and smoking; (4) regarding age and body mass index, there is no minimum or maximum, but clinical judgment should be used at extremes of either; (5) the ideal dose of PRP is undetermined; and (6) the minimal volume required is unclear and may depend on the pathology.

LEVEL OF EVIDENCE

Level V, expert opinion.

Use of custom glenoid components for reverse total shoulder arthroplasty

BACKGROUND

Our purpose was to evaluate a custom reverse total shoulder arthroplasty glenoid baseplate for severe glenoid deficiency, emphasizing the challenges with this approach, including short-term clinical and radiographic outcomes and complications.

METHODS

This was a single-institution, retrospective series of 29 patients between January 2017 and December 2022 for whom a custom glenoid component was created for extensive glenoid bone loss. Patients were evaluated preoperatively and at intervals for up to 5 years. All received preoperative physical examinations, plain radiographs, and computed tomography (CT). Intra- and postoperative complications are reported.

RESULTS

Of 29 patients, delays resulted in only undergoing surgery, and in three of those, the implant did not match the glenoid. For those three, the time from CT scan to implantation averaged 7.6 months (range, 6.1-10.7 months), compared with 5.5 months (range, 2-8.6 months) for those whose implants fit. In patients with at least 2-year follow-up (n=9), no failures occurred. Significant improvements were observed in all patient-reported outcome measures in those nine patients (American Shoulder and Elbow Score, P<0.01; Simple Shoulder Test, P=0.02; Single Assessment Numeric Evaluation, P<0.01; Western Ontario Osteoarthritis of the Shoulder Index, P<0.01). Range of motion improved for forward flexion and abduction (P=0.03 for both) and internal rotation up the back (P=0.02). Pain and satisfaction also improved (P<0.01 for both).

CONCLUSIONS

Prolonged time (>6 months) from CT scan to device implantation resulted in bone loss that rendered the implants unusable. Satisfactory short-term radiographic and clinical follow-up can be achieved with a well-fitting device. Level of evidence: III.

Next-generation Sequencing Results Require Higher Inoculum for Cutibacterium acnes Detection Than Conventional Anaerobic Culture

BACKGROUND

Cutibacterium acnes has been described as the most common causative microorganism in prosthetic shoulder infections. Conventional anaerobic culture or molecular-based technologies are usually used for this purpose, but little to no concordance between these methodologies (k = 0.333 or less) has been observed.

QUESTIONS/PURPOSES

(1) Is the minimum C. acnes load for detection higher for next-generation sequencing (NGS) than for anaerobic conventional culture? (2) What duration of incubation is necessary for anaerobic culture to detect all C. acnes loads?

METHODS

Five C. acnes strains were tested for this study: Four strains were causing infection and were isolated from surgical samples. Meanwhile, the other was a reference strain commonly used as a positive and quality control in microbiology and bioinformatics. To create inoculums with varying degrees of bacterial load, we began with a standard bacterial suspension at 1.5 x 10 8 colony-forming units (CFU)/mL and created six more diluted suspensions (from 1.5 x 10 6 CFU/mL to 1.5 x 10 1 CFU/mL). Briefly, to do so, we transferred 200 µL from the tube with the highest inoculum (for example, 1.5 x 10 6 CFU/mL) to the following dilution tube (1.5 x 10 5 CFU/mL; 1800 µL of diluent + 200 µL of 1.5 x 10 6 CFU/mL). We serially continued the transfers to create all diluted suspensions. Six tubes were prepared per strain. Thirty bacterial suspensions were tested per assay. Then, 100 µL of each diluted suspension was inoculated into brain heart infusion agar with horse blood and taurocholate agar plates. Two plates were used per bacterial suspension in each assay. All plates were incubated at 37°C in an anaerobic chamber and assessed for growth after 3 days of incubation and daily thereafter until positive or Day 14. The remaining volume of each bacterial suspension was sent for NGS analysis to identify bacterial DNA copies. We performed the experimental assays in duplicate. We calculated mean DNA copies and CFUs for each strain, bacterial load, and incubation timepoint assessed. We reported detection by NGS and culture as a qualitative variable based on the identification or absence of DNA copies and CFUs, respectively. In this way, we identified the minimum bacterial load detected by NGS and culture, regardless of incubation time. We performed a qualitative comparison of detection rates between methodologies. Simultaneously, we tracked C. acnes growth on agar plates and determined the minimum incubation time in days required for CFU detection in all strains and loads examined in this study. Growth detection and bacterial CFU counting were performed by three laboratory personnel, with a high intraobserver and interobserver agreement (κ > 0.80). A two-tailed p value below 0.05 was considered statistically significant.

RESULTS

Conventional cultures can detect C. acnes at a load of 1.5 x 10 1 CFU/mL, whereas NGS can detect bacteria when the concentration was higher, at 1.5 x 10 2 CFU/mL. This is represented by a lower positive detection proportion (73% [22 of 30]) for NGS than for cultures (100% [30 of 30]); p = 0.004). By 7 days, anaerobic cultures were able to detect all C. acnes loads, even at the lowest concentrations.

CONCLUSION

When NGS is negative and culture is positive for C. acnes , there is likely a low bacterial load. Holding cultures beyond 7 days is likely unnecessary.

CLINICAL RELEVANCE

This is important for treating physicians to decide whether low bacterial loads necessitate aggressive antibiotic treatment or whether they are more likely contaminants. Cultures that are positive beyond 7 days likely represent contamination or bacterial loads even below the dilution used in this study. Physicians may benefit from studies designed to clarify the clinical importance of the low bacteria loads used in this study at which both methodologies' detection differed. Moreover, researchers might explore whether even lower C. acnes loads have a role in true periprosthetic joint infection.

A modified Delphi consensus statement on patellar instability: part I

Aims

The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach.

Methods

A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous.

Results

Of 27 questions and statements on patellar instability, three achieved unanimous consensus, 14 achieved strong consensus, five achieved consensus, and five did not achieve consensus.

Conclusion

The statements that reached unanimous consensus were that an assessment of physeal status is critical for paediatric patients with patellar instability. There was also unanimous consensus on early mobilization and resistance training following nonoperative management once there is no apprehension. The statements that did not achieve consensus were on the importance of immobilization of the knee, the use of orthobiologics in nonoperative management, the indications for MPFC repair, and whether a vastus medialis oblique advancement should be performed.

Functional outcomes and complications of patients contaminated with Cutibacterium acnes during primary reverse shoulder arthroplasty: study at two- and five-years of follow-up

PURPOSE

The objective of the study was to compare the functional outcomes and the complication rate of the patients with C. acnes contamination at the end of the primary reverse shoulder arthroplasty (RSA) surgery to those patients without C. acnes contamination.

METHOD

A total of 162 patients were included. In all cases, skin and deep tissue cultures were obtained. A molecular typing characterization of the C. acnes strains was performed. Functional outcomes were assessed with the Constant score at the two and five year follow-up and all complications were also recorded.

RESULTS

A total of 1380 cultures were obtained from the 162 primary RSA surgeries. Of those, 96 turned out to be positive for C. acnes. There were 25 patients with positive cultures for C. acnes. The overall postoperative Constant score was not significantly different between those patients having C. acnes-positive cultures and those with negative cultures at the two and five year follow-up (59.2 vs. 59.6 at two years, p 0.870, and 59.5 vs. 62.4 at five years, p 0.360). Patients with positive cultures presented a higher complication rate (p 0.001) with two infections, one revision surgery, and one dislocation.

CONCLUSION

Patients ending up with C. acnes-positive cultures after primary shoulder arthroplasty surgery do not have worse clinical outcomes when compared to patients having negative cultures, but a greater number of complications were found in those patients with C. acnes-positive cultures.

Transcutaneous compression suture with iodine gauze for wound closure in revision surgery for therapy-resistant periprosthetic shoulder infections

Background

To successfully treat a periprosthetic infection, successful bacteria eradication and successful wound closure are mandatory. Despite adequate surgical débridement in the deep, persistence of wound drainage and subsequent persistence of periprosthetic infection may occur, especially in patients with compromised soft tissue conditions. This study presents a transcutaneous compression suture technique with iodine gauze that was used in patients with persistent wound secretion in therapy-resistant periprosthetic shoulder infections in order to achieve successful infection control and wound healing.

Methods

All patients with persistent periprosthetic or implant-associated shoulder joint infections despite correct previous surgical and antibiotic therapy attempts were included in the study. In all patients, in addition to repeat deep surgical débridement, a transcutaneous "iodine-gauze-compression-suture" was performed with postoperative antibiotic therapy. The primary endpoint was infection control; the secondary endpoint was wound healing rate; and the third endpoint was complication rate after index surgery.

Results

Ten consecutive patients with a mean age of 74 (±7.6) years and a mean follow-up of 14 (±2) months were included. All ten patients showed infection control and successful wound healing, with no need for further revision surgery. In 8 out of 10 patients, the wound healing was fast and completely uncomplicated. Two out of 10 patients showed delayed wound healing with fibrin coatings for 3 and 4 weeks, respectively. No additional intervention was necessary in both patients.

Conclusions

Transcutaneous iodine gauze compression sutures were used to achieve successful infection control without additional revision surgery in 10 out of 10 patients who previously underwent surgery with failed infection control. This wound closure technique is a reliable adjunctive therapy method in the treatment of implant-associated infections of the shoulder in patients with fragile wound conditions.

Periprosthetic Joint Infection: Current Clinical Challenges

Over the last several decades, periprosthetic joint infection has been increasing in incidence and is occurring in more complex patients. While there have been advances in both surgical and medical treatment strategies, there remain important gaps in our understanding. Here, we share our current approaches to the diagnosis and management of periprosthetic joint infection, focusing on frequent clinical challenges and collaborative interdisciplinary care.

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.

Diagnostic arthroscopy for periprosthetic shoulder arthroplasty infections: a systematic review and meta-analysis

Background

Periprosthetic joint infection of the shoulder (PJI) is a devastating complication with a reported incidence of 1%-15.4% and is often difficult to diagnose with current diagnostic tools including serologic tests and arthrocentesis. This systematic review evaluates the reliability and validity of arthroscopic biopsy in the current literature for the diagnosis of shoulder PJI.

Methods

MEDLINE, Scopus, Web of Sciences, Google Scholar, and Cochrane databases were queried electronically from inception to June 2022 for publications reporting diagnostic accuracy of shoulder arthroscopic biopsy for detecting infection after anatomic total shoulder arthroplasty, shoulder hemiarthroplasty, or reverse total shoulder arthroplasty. This systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Results

After exclusion, our meta-analysis consisted of 7 articles with a total of 112 patients. The estimated pooled sensitivity and specificity of arthroscopic biopsy for confirmation of shoulder periprosthetic infection were 0.87 (95% confidence interval [CI]: 0.73-0.95) and 0.79 (95% CI: 0.67-0.88), respectively. The pooled positive likelihood ratio and negative likelihood ratio were 4.15 (95% CI: 2.57, 6.70) and 0.17 (95% CI: 0.08, 0.36), respectively. The aggregate positive predictive value was 73.58% (95% CI: 63.29%-81.82%), and aggregate negative predictive value was 89.83% (95% CI: 80.59%-94.95%). The diagnostic odds ratio of arthroscopic biopsy was 19.92 (95% CI: 4.96-79.99).

Conclusion

Arthroscopic biopsy in patients suspected of shoulder PJI has good diagnostic accuracy, with high sensitivity and specificity. Given the various biopsy protocols (such as devices, numbers, locations, etc.), further prospective studies are necessary to define the future role of arthroscopic biopsy in diagnosis and treatment.

Vancomycin powder embedded in collagen sponge decreases the rate of prosthetic shoulder infection

BACKGROUND

Shoulder arthroplasty is a successful procedure to treat degenerative and traumatic diseases of the glenohumeral joint. Periprosthetic infection represents an infrequent but dreaded complication (2%-4%). Application of intrawound vancomycin powder seems to reduce periprosthetic infections, but limited information is available on its efficiency in shoulder arthroplasty. The purpose of this study was to evaluate if the vancomycin powder embedded in a collagen sponge could decrease the rate of prosthetic shoulder infection.

METHODS

A retrospective analysis of 827 patients undergoing total shoulder arthroplasty was performed. The study involved a control group of 405 patients and a group of 422 with the intraoperative insertion of intrawound vancomycin powder. Incidence of periprosthetic infection was evaluated comparing the 2 groups at a minimum follow-up of 12 months. Patient demographics, comorbidities, and perioperative information were compared between the 2 groups.

RESULTS

No infection was observed in the group treated with intrawound vancomycin, and 13 cases of infection were observed in the control group (3.2%) (P value <.001) without subacromial vancomycin application. No wound complications requiring revision were observed as a result of intrawound vancomycin application.

DISCUSSION AND CONCLUSION

Intrawound vancomycin powder significantly reduces the rate of periprosthetic shoulder infections without any increase in local and systemic aseptic complications at a minimum follow-up of 12 months. Our results support the use of intrawound local vancomycin for prophylaxis of shoulder periprosthetic infections.

The role of sonication in the diagnosis of periprosthetic joint infection in total shoulder arthroplasty

An increased sensitivity of sonication compared to periprosthetic tissue cultures in the diagnosis of periprosthetic joint infection (PJI) of hip and knee arthroplasty has been reported. The goal of this study was to determine if there is also an added value of implant sonication in the diagnosis of PJI in total shoulder arthroplasty (TSA). A retrospective analysis of patients who underwent removal of their TSA combined with sonication of the implant for suspicion of PJI between April 2009 and August 2017 was performed. The diagnosis of PJI was based on the major criteria described by Parvizi. We calculated sensitivity, specificity, predictive values, likelihood ratios and diagnostic accuracy for sonication cultures in comparison with periprosthetic tissue cultures. Data from 41 patients were analysed. Standard synovial fluid cultures combined with intraoperative periprosthetic tissue cultures had a sensitivity of 95%, specificity of 95% and total accuracy of 95%. Sonication cultures had a sensitivity of 91%, specificity of 68% and total accuracy of 80%. Six patients had negative standard cultures but positive sonication cultures. In patients with only one positive standard culture, the pathogen of the sonication culture corresponded to the pathogen of the positive soft tissue culture. We found a possible added value of sonication of TSA in the diagnosis of PJI in conjunction with standard intraoperative cultures. In some patients with suspicion of low-grade TSA infection, sonication could identify a possible causal microorganism despite negative standard cultures.

Dynamics of Cutibacterium repopulation onto the skin surface of the shoulder after chlorhexidine application

PURPOSE

The objective of this study was to characterize the temporal dynamics of Cutibacterium repopulation of the skin surface after application of chlorhexidine to the shoulder.

METHODS

Ten shoulders in five male subjects were used. A skin swab was taken prior to (0 minutes) and then at three, 30, 60, 120, and 240 minutes after skin preparation with 2% chlorhexidine gluconate and 70% isopropyl alcohol. Semi-quantitative bacterial load was measured for each timepoint.

RESULTS

From zero minutes (pre-treatment) to three minutes, chlorhexidine-isopropyl alcohol reduced the skin bacterial load in eight out of ten shoulders. Of these eight shoulders, four (50%) had growth by 30 minutes, seven (88%) had growth by 60 minutes, and all eight (100%) had growth by 240 minutes. Compared to the three minutes after chlorhexidine application, bacterial load had significantly increased by 60 minutes but were still significantly lower than the pre-prep bacterial load (0 minutes).

CONCLUSION

Following standard surgical skin preparation with chlorhexidine-isopropyl alcohol, the surface of the shoulder is repopulated with Cutibacterium within one hour, presumably from reservoirs in sebaceous glands not penetrated by topical antiseptic agents. Since these dermal glands are transected by skin incision for shoulder arthroplasty, this study suggests that they may be sources of wound contamination during surgery in spite of skin preparation with chlorhexidine.

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.

Update on Shoulder Arthroplasties with Emphasis on Imaging

Shoulder pain and dysfunction may significantly impact quality of life. If conservative measures fail, advanced disease is frequently treated with shoulder arthroplasty, which is currently the third most common joint replacement surgery following the hip and knee. The main indications for shoulder arthroplasty include primary osteoarthritis, post-traumatic arthritis, inflammatory arthritis, osteonecrosis, proximal humeral fracture sequelae, severely dislocated proximal humeral fractures, and advanced rotator cuff disease. Several types of anatomic arthroplasties are available, such as humeral head resurfacing and hemiarthroplasties, as well as total anatomic arthroplasties. Reverse total shoulder arthroplasties, which reverse the normal ball-and-socket geometry of the shoulder, are also available. Each of these arthroplasty types has specific indications and unique complications in addition to general hardware-related or surgery-related complications. Imaging-including radiography, ultrasonography, computed tomography, magnetic resonance imaging, and, occasionally, nuclear medicine imaging-has a key role in the initial pre-operative evaluation for shoulder arthroplasty, as well as in post-surgical follow-up. This review paper aims to discuss important pre-operative imaging considerations, including rotator cuff evaluation, glenoid morphology, and glenoid version, as well as to review post-operative imaging of the various types of shoulder arthroplasties, to include normal post-operative appearances as well as imaging findings of complications.

Revision of total shoulder arthroplasty to hemiarthroplasty: results at mean 5-year follow-up

BACKGROUND

Although there is a trend to manage failed anatomic total shoulder arthroplasties (aTSA) with revision to a reverse total shoulder arthroplasty, such revisions can be complicated by difficulties in baseplate fixation, instability, and acromial stress fractures. Some cases of failed aTSA may be safely revised to a hemiarthroplasty (HA). The objectives of this study were to report patient-reported outcomes after conversion from aTSA to HA and assess patient and shoulder characteristics associated with a successful outcome.

METHODS

Patients who underwent revision from aTSA to HA between 2009 and 2018 were contacted. Patient demographics, surgical history, intraoperative findings, and microbiology results were collected. Patient-reported outcomes were collected with minimum 2-year follow-up. Preoperative radiographic characteristics were reviewed for component positioning and component loosening. Patients with a clinically significant improvement exceeding the minimal clinically important difference (MCID) of the Simple Shoulder Test (SST) were compared with those patients who did not improve past the MCID.

RESULTS

Twenty-nine patients underwent conversion from aTSA to HA with a mean follow-up of 4.5 ± 1.8 years. Intraoperative glenoid or humeral component loosening was found in all 29 patients. Pain improved in 25 of 30 patients (87%), and mean pain scores improved from 6.2 ± 2.3 to 3.1 ± 2.4 (P < .001). SST scores improved from 4.1 ± 3.1 to 7.3 ± 3.2 (P < .001), and 18 of 29 patients (62%) had improvement above the SST MCID threshold of 2.4. The mean American Shoulder and Elbow Surgeons score at the latest follow-up was 64 ± 19, and the Single Assessment Numeric Evaluation score was 65 ± 23. Twenty-two of 29 (76%) patients were satisfied with the procedure. Four patients (14%) required conversion to total shoulder arthroplasty-2 to anatomic and 2 to reverse. An additional 3 patients (10%) had a revision HA performed. No significant differences in patient or shoulder characteristics were found in those patients who improved greater than the MCID of the SST compared patients who improved less than the MCID of the SST. Fifty-nine percent of patients had ≥2 positive cultures with the same bacteria, and 82% of these were with Cutibacterium. Seven of 8 patients (88%) with a loose humeral component had ≥2 positive cultures with the same bacteria.

DISCUSSION

Component loosening is a common failure mode after aTSA. Revision to HA can improve pain and patient-reported outcomes in most patients.

The role of serum D-Dimer for the diagnosis of periprosthetic shoulder infection

INTRODUCTION

D-Dimer was recently identified as an additional biomarker in the diagnosis of hip and knee periprosthetic joint infection (PJI). Currently, there is only one study in literature dealing with the role of D-Dimer in the diagnosis of shoulder PJI. The purpose of this study was, therefore, to validate the sensitivity and specificity of D-Dimer in detecting shoulder PJI.

MATERIALS AND METHODS

All patients, who underwent septic or aseptic revision shoulder arthroplasty in our institution between November 2018 und March 2021, were analyzed. Our cohort consisted of 30 patients, of that 14 (47%) had a shoulder PJI according the last proposed criteria of the International Consensus Meeting. The diagnostic validity of serum D-Dimer regarding the detection of PJI was analyzed.

RESULTS

The mean D-Dimer level was significantly higher for the patients with shoulder PJI compared to patients with aseptic failure (1.44 ± 1 mg/l vs. 0.76 ± 0.6 mg/l, p = 0.025). Coagulase-negative staphylococci were the most commonly isolated pathogens, in 9/14 patients (64%), followed by Cutibacterium acnes in 5/14 patients (36%). According to the ROC analysis, a serum D-Dimer threshold of 0.75 mg/l had a sensitivity of 86% and a specificity of 56% for detection of a shoulder PJI. The area under curve was 0.74. A serum C-reactive protein (CRP) cutoff of 10 mg/l showed a sensitivity of 69% and a specificity of 88%. When both serum D-Dimer and CRP above the thresholds of 0.75 mg/l and 10 mg/l, respectively, were used to identify a PJI the sensitivity and specificity were 57% and 100%, respectively.

CONCLUSIONS

Serum D-Dimer showed a good sensitivity but a poor specificity for the diagnosis of shoulder PJI. Combination D-Dimer and CRP led to improvement of the specificity, however, at the cost of sensitivity. Thus, combination of both methods may be used as a confirmatory test in the diagnosis of shoulder PJI but not to rule out infection.

LEVEL OF EVIDENCE

Diagnostic level II.

Rice-Body Synovitis, Foreign Body Reaction, and Rotator Cuff Failure After Subacromial Balloon Spacer Augmentation of a Rotator Cuff Repair: A Case Report

CASE

A 66-year-old woman presented with shoulder pain and weakness 4 months after augmentation of a rotator cuff repair with a Stryker InSpace subacromial balloon spacer. A magnetic resonance imaging (MRI) demonstrated a failed rotator cuff repair, large effusion with rice bodies, synovitis, axillary lymphadenopathy, loose anchors, and erosive changes to the greater tuberosity. Arthroscopy revealed balloon fragmentation surrounded by diffusely hyperemic synovium without repairable cuff tissue. Final cultures proved negative for infection. Histologic evaluation revealed ulcerated synovium with diffuse chronic and focal acute inflammation.

CONCLUSION

Despite promising early results, augmentation of a rotator cuff repair with a subacromial balloon spacer introduces a risk of inflammatory reaction that may mimic a deep infection and compromise rotator cuff healing.

The Association of Benign Prostatic Hyperplasia on Postoperative Complications and Periprosthetic Joint Infections Following Total Shoulder Arthroplasty

Background

A recently proposed risk factor for periprosthetic joint infections (PJI) in men is benign prostatic hyperplasia (BPH). The objective was to explore the association of BPH on 1) 90-day complications, 2) length of stay (LOS), 3) readmission rates, and 4) healthcare expenditures following total shoulder arthroplasty (TSA).

Methods

A retrospective query was performed using a nationwide claims database from January 2005 to March 2014 for male patients undergoing primary TSA. The study cohort included 5067 patients with BPH while 50,720 patients served as the comparison cohort. Logistic regression determined the association of BPH on complications and readmissions. A p value less than 0.001 was significant.

Results

Patients with BPH had higher incidence and odds (36.8 vs. 6.2%; OR: 2.73, p < 0.0001) of all ninety-day medical complications including PJIs (0.49 vs. 0.32%; OR: 1.54, p < 0.001). BPH patients had longer in-hospital LOS (3- vs. 2-days, p < 0.0001). Study group patients had higher 90-day episode of care reimbursements ($13,653 vs. $12,688), p < 0.0001).

Conclusions

BPH is associated with increased complications and healthcare expenditures following total shoulder arthroplasty. The investigation can be used to educate BPH patients of the possible adverse events which may occur within ninety-days following primary TSA for the treatment of glenohumeral osteoarthritis.

What is the concordance rate of preoperative synovial fluid aspiration and intraoperative biopsy in detecting periprosthetic joint infection of the shoulder?

BACKGROUND

The accuracy of preoperative synovial fluid culture for microbe detection in shoulder periprosthetic joint infection (PJI) is poorly described. To evaluate the utility of preoperative culture data for early pathogen identification for shoulder PJI, we determined the concordance between preoperative synovial fluid culture results and intraoperative tissue culture results.

METHODS

Fifty patients who met the 2014 Musculoskeletal Infection Society criteria for shoulder PJI between January 2016 and December 2019 were retrospectively reviewed for clinical and demographic data. This cohort of patients was divided into 2 groups based on the concordance between preoperative and intraoperative culture results. The pathogens identified on preoperative and intraoperative cultures were classified as high-virulence or low-virulence. Student's t tests and Mann-Whitney U tests were used as appropriate for continuous variables, and χ² and Fisher's exact tests were used as appropriate for categorical variables.

RESULTS

Concordance between preoperative aspiration and intraoperative tissue culture was identified in 28 of 50 patients (56%). Preoperative cultures positive for Gram-positive species were more likely to be concordant than discordant (P = .015). Preoperative cultures positive for Cutibacterium acnes were more likely to be concordant with intraoperative cultures (P = .022). There were more patients with polymicrobial infection in the discordant group compared with the concordant group (P < .001). No statistically significant correlation between the preoperative serum C-reactive protein level and the intraoperative category of bacteria was reported. Staphylococcus aureus and coagulase-negative Staphylococci were associated with high specificity and negative predictive value. Preoperative cultures positive for C. acnes demonstrated sensitivity, specificity, positive predictive value, and negative predictive value lower than 0.8. Gram-negative pathogens demonstrated the highest sensitivity (1) and specificity (1), whereas polymicrobial infections exhibited the lowest sensitivity and positive predictive value.

CONCLUSION

Preoperative synovial fluid aspiration for shoulder PJI poorly predicts intraoperative culture results, with a discordance of 44%. More favorable concordance was observed for monomicrobial preoperative cultures, particularly for Gram-negative organisms and methicillin-sensitive S. aureus. The overall high rate of discordance between preoperative and intraoperative culture may prompt surgeons to base medical and surgical management on patient history and other factors and avoid relying solely on preoperative synovial fluid culture data.

Success of staged revision reverse total shoulder arthroplasty in eradication of periprosthetic joint infection

INTRODUCTION

Management of periprosthetic joint infection (PJI) in shoulder arthroplasty remains a challenge, with no established gold standard treatment. This study presents the unique experience of a high-volume single-surgeon, single-institution approach on staged revision reverse total shoulder arthroplasty (RTSA) for infection. The authors theorize that staged revision RTSA is an effective treatment for PJI.

MATERIALS AND METHODS

Between 2013 and 2018, 38 patients underwent a staged RTSA for treatment of PJI. Patient histories were collected and classified using Cierny-Mader classification. Infection workup for all patients included radiographs, laboratory indices, and computed tomographic aspiration arthrogram. PJI was identified based on high clinical and radiographic suspicion, elevated serologic markers, and/or aspirate culture results per 2018 International Consensus Meeting Shoulder guidelines on Orthopedic Infections. All patients underwent first stage with implant removal, irrigation and débridement, and antibiotic spacer placement. Next, intravenous antibiotics were administered by infectious disease consultants for a minimum of 6 weeks. Infection workup was then repeated and, if normalized, final-stage revision commenced with antibiotic spacer removal and revision to RTSA. If indices were persistently abnormal, an additional stage of débridement and spacer placement procedure was performed. Treatment failure was defined as recurrent periprosthetic infection after final prosthesis implantation or persistently elevated indices despite adequate débridement and spacer placement.

RESULTS

Mean age of the cohort was 68 (standard deviation [SD] 8.9) years and mean follow-up was 33 (SD 14) months with 34 Cierny-Mader C hosts and 4 B hosts. Patients underwent a mean of 2 (SD 1.1) previous surgeries. The staged revision protocol was successful in 34 (89.5%) patients for management of PJI. Four patients (10.5%) were considered failures with recurrent infections at a mean of 13 months (range 2-26 months) after the final RTSA implantation and underwent repeat staged revisions. Of the 34 patients who had successful infection eradication, 31 had 2-stage treatment and 3 had to undergo 3 stages. There were no treatment-associated mortalities and 10 major complications (26%), including permanent neuropathy, instability, and periprosthetic fractures. The most common cultured microorganism was Cutibacterium acnes (18%), with no polymicrobial infections detected.

DISCUSSION

Although there are multiple treatment options for PJI management, staged revision remains an effective means of treatment. Although there were several patients who required an additional stage of treatment, and a significant complication rate, staged revision RTSA proved successful in the ultimate eradication of the PJI.

Predictors of success following single-stage revision shoulder arthroplasty: results at a mean of five year follow-up in one hundred and twelve patients

PURPOSE

The objective was to determine factors associated with a successful outcome at a minimum of two years after revision of a failed shoulder arthroplasty.

METHODS

We conducted a retrospective study of revision shoulder arthroplasties performed over a ten year period and collected patient-reported outcome data and re-revision data. A successful outcome was defined by improvement greater than the minimal clinically important difference (MCID) for the Simple Shoulder Test (SST).

RESULTS

One hundred twelve patients with average follow-up of five years were included. Improvement of VAS pain scores (6.6 ± 2.3 to 2.9 ± 2.6) and SST scores (2.7 ± 2.6 to 6.6 ± 3.3) were significant (p < 0.001). Males were more likely to have a successful outcome than females (p = 0.01).

CONCLUSION

Two-thirds of patients experienced clinically significant improvement at a minimum of two years after revision shoulder arthroplasty. Male sex was the strongest independent predictor of a successful outcome.

Evaluation of the Painful Total Shoulder Arthroplasty

Despite the overall success of anatomic and reverse total shoulder arthroplasties (aTSA and rTSA), some patients continue to have or develop pain postoperatively. As the number of shoulder arthroplasties continues to increase in the United States, it is important that surgeons are able to recognize, diagnose, and treat the various pathologies. Some painful etiologies are specific to either aTSA or rTSA, and others can occur with both implant types. Infections, stiffness, neurologic syndromes, polyethylene wear, aseptic implant loosening, and metal allergies occur, regardless of implant choice. However, after an aTSA, subscapularis repair failure, superior rotator cuff tear, and joint overstuffing can result in shoulder pain. After a rTSA, specific causes of postoperative pain include instability, scapular notching, acromial or scapular spine fractures, subcoracoid pain, and neurologic injury. Regardless of the diagnosis, the surgeon must be methodical in the evaluation and, when appropriate, use blood work, advanced imaging studies, joint aspirations, shoulder arthroscopy, and nerve studies. Once diagnosed, appropriate treatment should be undertaken to resolve the cause of the pain or at least minimize the effect of the pain on the patient's outcome.

Ulnar Collateral Ligament Tears: A Modified Consensus Statement

PURPOSE

The purpose of this study was to establish consensus statements on the treatment of UCL injuries and to investigate whether consensus on these distinct topics could be reached.

METHODS

A modified consensus technique was conducted among twenty-six elbow surgeons and 3 physical therapists/athletic trainers. Strong consensus was defined as 90-99% agreement.

RESULTS

Of the 19 total questions and consensus statements 4 achieved unanimous consensus, 13 achieved strong consensus, and 2 did not achieve consensus.

CONCLUSION

There was unanimous agreement that the risk factors include overuse, high velocity, poor mechanics, and prior injury. There was unanimous agreement that advanced imaging in the form of either an MRI or MRA should be performed in a patient presenting with suspected/known UCL tear that plans to continue to play an overhead sport, or if the imaging study could change the management of the patient. There was unanimous agreement regarding lack of evidence for the use of orthobiologics in the treatment of UCL tears as well as the areas pitchers should focus on when attempting a course of non-operative management. The statements that reached unanimous agreement for operative management were regarding operative indications and contraindications for UCL tears, prognostic factors that should be taken into consideration in when performing UCL surgery, how to deal with the flexor-pronator mass during UCL surgery and use of an internal brace with UCL repairs. Statements that reached unanimous agreement for RTS were regarding: portions of the physical exam should be considered when determining whether to allow a player to RTS, unclear how velocity, accuracy, and spin rate should be factored into the decision of when players can RTS and sports psychology testing should be used to determine whether a player is ready to RTS.

LEVEL OF EVIDENCE

Expert opinion (Level V).

Previous rotator cuff repair increases the risk of revision surgery for periprosthetic joint infection after reverse shoulder arthroplasty

BACKGROUND

Previous studies have indicated an increased risk of periprosthetic joint infection (PJI) in patients treated with reverse shoulder arthroplasty (RSA) compared with patients treated with anatomic total shoulder arthroplasty. The reason for this is unclear but may be related to a high prevalence of previous rotator cuff repair in patients who are treated with RSA. The purpose of this study was to determine previous non-arthroplasty surgery as a risk factor for revision owing to PJI after RSA for cuff tear arthropathy, massive irreparable rotator cuff tears, or osteoarthritis.

METHODS

Data were retrieved from the Danish Shoulder Arthroplasty Registry and medical records. We included 2217 patients who underwent RSA for cuff tear arthropathy, massive irreparable rotator cuff tears, or osteoarthritis between 2006 and 2019. PJI was defined as ≥3 of 5 tissue samples positive for the same bacteria or as definite or probable PJI evaluated based on criteria from the International Consensus Meeting. The Kaplan-Meier method was used to illustrate the unadjusted 14-year cumulative rates of revision. A Cox regression model was used to report hazard for revision owing to PJI. Results were adjusted for previous non-arthroplasty surgery, sex, diagnosis, and age.

RESULTS

Revision was performed in 88 shoulders (4.0%), of which 40 (1.8%) underwent revision owing to PJI. There were 272 patients (12.3%) who underwent previous rotator cuff repair, of whom 11 (4.0%) underwent revision owing to PJI. The 14-year cumulative rate of revision owing to PJI was 14.1% for patients with previous rotator cuff repair and 2.7% for patients without previous surgery. The adjusted hazard ratio for revision owing to PJI for patients with previous rotator cuff repair was 2.2 (95% confidence interval, 1.04-4.60) compared with patients without previous surgery.

CONCLUSION

There is an increased risk of revision owing to PJI after RSA for patients with previous rotator cuff repair. We recommend that patients with previous rotator cuff repair be regarded as high-risk patients when considering RSA.

Periprosthetic joint infections of the shoulder: A 10-year retrospective analysis outlining the heterogeneity among these patients

Background

Diagnosis and treatment of shoulder periprosthetic joint infection is a difficult problem. The purpose of this study was to utilize the 2018 International Consensus Meeting definition of shoulder periprosthetic joint infection to categorize revision shoulder arthroplasty cases and determine variations in clinical presentation by presumed infection classification.

Methods

Retrospective review of patients undergoing revision shoulder arthroplasty at a single institution. Likelihood of periprosthetic joint infection was determined based on International Consensus Meeting scoring. All patients classified as definitive or probable periprosthetic joint infection were classified as periprosthetic joint infection. All patients classified as possible or unlikely periprosthetic joint infection were classified as aseptic. The periprosthetic joint infection cohort was subsequently divided into culture-negative, non-virulent microorganism, and virulent microorganism cohorts based on culture results.

Results

Four hundred and sixty cases of revision shoulder arthroplasty were reviewed. Eighty (17.4%) patients were diagnosed as definite or probable periprosthetic joint infection, of which 29 (36.3%), 39 (48.8%), and 12 (15.0%) were classified as virulent, non-virulent, or culture-negative periprosthetic joint infection, respectively. There were significant differences among periprosthetic joint infection subgroups with regard to preoperative C-reactive protein (p = 0.020), erythrocyte sedimentation rate (p = 0.051), sinus tract presence (p = 0.008), and intraoperative purulence (p < 0.001). The total International Consensus Meeting criteria scores were also significantly different between the periprosthetic joint infection cohorts (p < 0.001).

Discussion

While the diagnosis of shoulder periprosthetic joint infection has improved with the advent of International Consensus Meeting criteria, there remain distinct differences between periprosthetic joint infection classifications that warrant further investigation to determine the accurate diagnosis and optimal treatment.

An evidence-based approach to managing unexpected positive cultures in shoulder arthroplasty

BACKGROUND

Unexpected positive cultures (UPCs) are very commonly found during shoulder arthroplasty when surgeons send intraoperative cultures to rule out periprosthetic joint infection (PJI) without clinical or radiographic signs of infection. Cutibacterium acnes is thought to be the most common bacteria cultured in this setting; however, the implications of an unexpected positive result are neither well defined nor agreed upon within the literature. The current review evaluates the incidence of UPCs and C acnes in reverse total arthroplasty; the clinical significance, if any, of these cultures; and various prognostic factors that may affect UPC incidence or recovery following PJI.

METHODS

A systematic review was performed with PRISMA guidelines using PubMed, CINAHL, and Scopus databases. Inclusion criteria included studies published from January 1, 2000, to May 20, 2021, that specifically reported on UPCs, native or revision shoulder surgery, and any study that directly addressed one of our 6 proposed clinical questions. Two independent investigators initially screened 267 articles for further evaluation. Data on study design, UPC rate/speciation, UPC risk factors, and UPC outcomes were analyzed and described.

RESULTS

A total of 22 studies met the inclusion criteria for this study. There was a pooled rate of 27.5% (653/2373) deep UPC specimen positivity, and C acnes represented 76.4% (499/653) of these positive specimens. Inanimate specimen positivity was reported at a pooled rate of 20.1% (29/144) across 3 studies. Male patients were more likely to have a UPC; however, the significance of prior surgery, surgical approach, and type of surgery conflicted across multiple articles. Patient-reported outcomes and reoperation rates did not differ between positive-UPC and negative-UPC patients. The utilization of antibiotics and treatment regimen varied across studies; however, the reinfection rates following surgery did not statistically differ based on the inclusion of antibiotics.

CONCLUSION

UPCs are a frequent finding during shoulder surgery and C acnes represents the highest percentage of cultured bacteria. Various preoperative risk factors, surgical techniques, and postoperative treatment regimens did not significantly affect the incidence of UPCs as well as the clinical outcomes for UPC vs. non-UPC patients. A standardized protocol for treatment and follow-up would decrease physician uncertainty when faced with a UPC from shoulder surgery. Given the results of this review, shoulder surgeons can consider not drastically altering the postoperative clinical course in the setting of UPC with no other evidence of PJI.

Culturing explants for Cutibacterium at revision shoulder arthroplasty: an analysis of explant and tissue samples at corresponding anatomic sites

BACKGROUND

Culturing of deep tissues obtained at revision arthroplasty for Cutibacterium is a key component of diagnosing a periprosthetic infection. The value of culturing explanted components has not been well described. This study sought to answer the following questions: (1) How does the culture positivity of explant cultures compare with that of deep tissue cultures? (2) How often are explant cultures positive when tissue cultures are not, and vice versa? (3) How does the bacterial density in explant cultures compare with that in tissue cultures?

METHODS

A total of 106 anatomic arthroplasties revised over a 7-year period were included. Explant (humeral head, humeral stem, and glenoid) and tissue (collar membrane, humeral canal tissue, and periglenoid tissue) specimens were sent for semiquantitative Cutibacterium culture. We compared culture positivity and bacterial density when cultures of an explant and tissue adjacent to the implant were both available.

RESULTS

Explants had positive cultures at a higher rate than adjacent tissue specimens for most anatomic sites. Of the shoulders that had Cutibacterium growth, a higher proportion of explants were culture positive when tissue samples were negative (23%-43%) than vice versa (0%-21%). The Cutibacterium density was higher in explants than in tissues. Considering only the results of tissue samples, 16% of the shoulders met our threshold for infection treatment (≥2 positive cultures); however, with the inclusion of the results for explant cultures, additional 14% of cases-a total of 30%-met the criteria for infection treatment.

CONCLUSIONS

In this group of patients, culturing explants in addition to tissue cultures increased the sensitivity for detecting Cutibacterium in revision shoulder arthroplasty.

Changes in microbiological spectrum and antibiotic susceptibility in two-stage exchange for periprosthetic shoulder infections

BACKGROUND

Periprosthetic joint infections (PJI) are a major concern in shoulder arthroplasty, which in some cases require two-stage exchange. While it was shown that low-virulence bacteria are the most isolated pathogens in shoulder PJI, little is known about changes in microbiological spectrum and resistance patterns during two-stage revision.

METHODS

This retrospective study included all patients (n = 25) who received a two-stage revision from January 2011 to December 2020 for shoulder PJI in one institution. Microbiological spectrum, antimicrobial resistance patterns, and re-revision rates of culture positive first- and second-stage procedures were analyzed. The mean follow-up time was 29.7 months (range 8; 115 months). At final follow-up, subjective shoulder value (SSV) and visual analog scale (VAS) score for pain and satisfaction with the surgery were assessed.

RESULTS

In 25 patients, a total of 54 2-stage exchange procedures were performed and positive cultures were obtained in 36 of these surgeries (66.7%). A total of 7 out of 25 patients (28.0%) showed a positive microbiological culture at first and second stages. In those patients, the mean time between first and second stages was 30.9 weeks (range 6; 70). Three out of those seven patients (42.9%) had a polymicrobial spectrum with one microorganism persistent at stage two, including Cutibacterium acnes (n = 1) and Staphylococcus epidermidis (MRSE) (n = 2). In all these cases, antimicrobial resistance patterns changed. All cultures with monomicrobial spectrum (n = 4) at first stage showed a changed spectrum. Patients with positive first- and second-stage revisions showed a mean SSV of 49.3% ± 23.5 versus 52.9% ± 29.5 in single positive patients (p = 0.76). Re-revision was performed in five cases, two of those in patients with positive first- and second-stage cultures.

CONCLUSION

There is a high rate of changes in microbiological spectrum and resistance patterns between culture positive first- and second-stage procedures as well as subsequent re-revisions. Intraoperative samples during reimplantation should be taken and resistance reconsidered in case of re-revision.

The influence of prior dental pathology on medical complications and peri-prosthetic joint infections following primary shoulder arthroplasty

PURPOSE

Antibiotic prophylaxis before invasive dental procedures is a common practice in the USA. Consensus regarding the influence of prior dental pathology (DP) on postoperative complications is lacking. The objectives are to determine the association of DP prior to shoulder arthroplasty (SA) on: (1) lengths of stay (LOS), (2) medical complications, (3) readmissions, (4) implant-related complications including peri-prosthetic joint infections (PJIs) and (5) healthcare expenditures.

METHODS

The PearlDiver database was queried for primary shoulder arthroplasty from 2010 to 2020. Patients with history of dental caries or dental implant placement before SA represented the study group (n = 1419). Patients without prior DP represented controls (n = 7062). Study group patients were 1:5 ratio matched to controls by age, sex, and comorbidities. Outcomes included LOS, 90-day complications, readmissions, 2-year implant-related complications, and healthcare reimbursements. Logistic regression was used to calculate odds ratios (OR) of complications and readmissions. T tests compared LOS and costs. P values < 0.003 were significant.

RESULTS

LOS (2.17 vs. 2.07 days; p = 0.071) were similar between groups. Patients with DP had higher 90-day medical complications compared to controls (OR: 1.74, p < 0.0001), including myocardial infarctions (2.2% vs. 0.8%; OR: 2.79, p < 0.0001), acute kidney injuries (8.3% vs. 4.6%; OR: 1.92, p < 0.0001), and pneumonias (8.7% vs. 5.3%; OR: 1.72, p < 0.0001). Readmission rates (1.97% vs. 1.54%; p = 0.248) were similar. Two-year implant complications were higher in patients with DP compared to controls (16.1% vs. 11.5%; OR: 1.38, p = 0.0003), including dislocations (6.4% vs. 4.5%; OR: 1.45, p = 0.002) and mechanical loosenings (4.0% vs. 2.4%; OR: 1.67, p = 0.001); however, PJIs were similar (2.2% vs. 1.9%; OR: 1.12, p = 0.583). Healthcare expenditures between groups were similar ($12,611 vs. $12,059; p = 0.075).

CONCLUSION

Patients with prior DP have higher 90-day medical complications and 2-year implant-related complications. Two-year incidence of PJIs were similar between groups. These findings can help shoulder surgeons counsel patients with a pertinent dental history.

LEVEL OF EVIDENCE III

Retrospective comparative study.

Benign prostatic hyperplasia is associated with increased 90-day medical complications but not peri-prosthetic joint infections following reverse shoulder arthroplasty

INTRODUCTION

Studies have shown male sex to be a predisposing factor for peri-prosthetic joint infections (PJIs). Symptomatic benign prostatic hyperplasia (BPH) has been suggested as an additional risk for PJI. This study aimed to assess the impact of BPH on (1) lengths of stay (LOS), (2) complications (medical and implant-related), (3) readmission rates, and (4) healthcare expenditures after reverse shoulder arthroplasty (RSA).

METHODS

Utilizing a nationwide sample from the 2010-2020 PearlDiver insurance database, an analysis was performed retrospectively for all males who underwent primary RSA. Males with BPH (n = 2,184) represented the study group and were ratio-matched with men without a history of BPH (n = 10,832) in a 1:5 manner by medical comorbidities. T-tests compared LOS and healthcare expenditures. Multivariate logistic regression models were used to determine the effect of BPH on 90-day medical complications, 2-year implant complications, and readmissions. A p value less than 0.001 was statistically significant.

RESULTS

In-hospital LOS (1.96 days vs. 1.99 days, p = 0.683) did not significantly differ between cohorts. Males with BPH had significantly greater occurrence and odds (34.3% vs. 21.2%, odds ratio (OR):1.84, p < 0.0001) of all 90-day medical complications, including urinary tract infections (9.3% vs. 3.1%, OR:3.23, p < 0.0001), pneumonias (6.0% vs. 3.9%, OR:1.61, p < 0.0001), and acute kidney injuries (7.7% vs. 5.0%, OR:1.60, p < 0.0001). Two-year implant-related complications were comparable between study and control groups (12.2% vs 10.9%, OR:1.14, p = 0.073), including PJIs (2.3% vs. 2.2%, OR:1.02, p = 0.874). Readmission rates (1.88% vs. 2.11%, p = 0.482) and average global 90-day reimbursements ($26,301 vs. $24,399), p = 0.535) were similar between men with and without BPH.

DISCUSSION

Males with a history of BPH have greater rates of medical complications, including UTIs and acute kidney injuries, within 90 days following RSA. BPH does not appear to be a risk factor for 2-year implant-related complications including PJIs.

LEVEL OF EVIDENCE

III.

Diagnostic Performance of Advanced Metal Artifact Reduction MRI for Periprosthetic Shoulder Infection

BACKGROUND

The diagnosis of periprosthetic shoulder infection (PSI) in patients with a painful arthroplasty is challenging. Magnetic resonance imaging (MRI) may be helpful, but shoulder implant-induced metal artifacts degrade conventional MRI. Advanced metal artifact reduction (MARS) improves the visibility of periprosthetic bone and soft tissues. The purpose of our study was to determine the reliability, repeatability, and diagnostic performance of advanced MARS-MRI findings for diagnosing PSI.

METHODS

Between January 2015 and December 2019, we enrolled consecutive patients suspected of having PSI at our academic hospital. All 89 participants had at least 1-year clinical follow-up and underwent standardized clinical, radiographic, and laboratory evaluations and advanced MARS-MRI. Two fellowship-trained musculoskeletal radiologists retrospectively evaluated the advanced MARS-MRI studies for findings associated with PSI in a blinded and independent fashion. Both readers repeated their evaluations after a 2-month interval. Interreader reliability and intrareader repeatability were assessed with κ coefficients. The diagnostic performance of advanced MARS-MRI for PSI was quantified using sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC). When applying the International Consensus Meeting (ICM) 2018 criteria, of the 89 participants, 22 (25%) were deemed as being infected and 67 (75%) were classified as being not infected (unlikely to have PSA and not requiring a surgical procedure during 1-year follow-up).

RESULTS

The interreader reliability and intrareader repeatability of advanced MARS-MRI findings, including lymphadenopathy, joint effusion, synovitis, extra-articular fluid collection, a sinus tract, rotator cuff muscle edema, and periprosthetic bone resorption, were good (κ = 0.61 to 0.80) to excellent (κ > 0.80). Lymphadenopathy, complex joint effusion, and edematous synovitis had sensitivities of >85%, specificities of >90%, odds ratios of >3.6, and AUC values of >0.90 for diagnosing PSI. The presence of all 3 findings together yielded a PSI probability of >99%, per logistic regression analysis.

CONCLUSIONS

Our study shows the clinical utility of advanced MARS-MRI for diagnosing PSI when using the ICM 2018 criteria as the reference standard. Although the reliability and diagnostic accuracy were high, these conclusions are based on our specific advanced MARS-MRI protocol interpreted by experienced musculoskeletal radiologists. Investigations with larger sample sizes are needed to confirm these results.

LEVEL OF EVIDENCE

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

What do positive and negative Cutibacterium culture results in periprosthetic shoulder infection mean? A multi-institutional control study

BACKGROUND

Deep tissue culture specimens obtained at the time of revision shoulder arthroplasty are commonly positive for Cutibacterium. Clinical interpretation of positive cultures can be difficult. This was a multi-institutional study evaluating the accuracy of cultures for Cutibacterium using positive control (PC) and negative control (NC) samples. The relationship between time to culture positivity and strength of culture positivity was also studied.

METHODS

Eleven different institutions were each sent 12 blinded samples (10 PC and 2 NC samples). The 10 PC samples included 2 sets of 5 different dilutions of a Cutibacterium isolate from a failed total shoulder arthroplasty with a probable periprosthetic infection. At each institution, the samples were handled as if they were received from the operating room. Specimen growth, time to culture positivity, and strength of culture positivity (based on semiquantitative assessment) were reported.

RESULTS

A total of 110 PC samples and 22 NC samples were tested. One hundred percent of specimens at the 4 highest dilutions were positive for Cutibacterium. At the lowest dilution, 91% of samples showed positive findings. Cutibacterium grew in 14% of NC samples. Cutibacterium grew in PC samples at an average of 4.0 ± 1.3 days, and all of these samples showed growth within 7 days. The time to positivity was significantly shorter (P < .001) and the strength of positivity was significantly higher (P < .001) in true-positive cultures compared with false-positive cultures.

CONCLUSIONS

This multi-institutional study suggests that different institutions may report highly consistent rates of culture positivity for revision shoulder arthroplasty samples with higher bacterial loads. In contrast, with lower bacterial loads, the results are somewhat less consistent. Clinicians should consider using a shorter time to positivity and a higher strength of positivity as adjuncts in determining whether a tissue culture sample is a true positive.

The painful shoulder arthroplasty: appropriate work-up and review of interventional pain treatments

Shoulder arthroplasty is a successful surgical procedure for several conditions when patients become refractory to conservative management modalities. Unfortunately, some patients experience persistent chronic pain after shoulder arthroplasty. These individuals should undergo a comprehensive evaluation by an orthopedic surgeon to determine whether structural pathology is responsible for the pain and to decide whether reoperation is indicated. At times, a surgical solution does not exist. In these circumstances, a thorough and specific plan for the management of persistent chronic pain should be developed and instituted. In this article, we review common reasons for persistent pain after shoulder arthroplasty and outline the evaluation of the painful shoulder arthroplasty. We then provide a thorough review of interventional pain management strategies. Finally, we hypothesize developments in our field that might provide better outcomes in the future for patients suffering with chronic intractable pain after shoulder arthroplasty.

Risk factors for postoperative blood transfusion after shoulder arthroplasty

Purpose

To identify the effect of surgical indication, patient factors, and perioperative characteristics on transfusion after shoulder arthroplasty (SA).

Methods

Shoulder arthroplasties for osteoarthritis (OA) (N = 47), rotator cuff arthropathy (RCA) (N = 50), fracture (N = 76), revision (N = 66), and periprosthetic joint infection (PJI) (N = 35) performed at a single institution during a 6-year period were included. All other indications were excluded. Patient-based and surgical risk factors, including surgical indication, for postoperative allogeneic red blood cell transfusion were assessed with multivariate logistic regression analysis.

Results

A total of 274 SAs were included; transfusions were performed in 2% (2/97) of primary SAs for OA or RCA. Increased transfusion rates occurred in PJI (23%, p = 0.0006) and fracture (18%, p = 0.0018) cases. The mean preoperative hemoglobin (Hgb) was 12.2 ± 2.2 with PJI, 12.0 ± 2.1 with fracture, and 13.3 ± 1.6 g/dL for all other SAs. Independent risk factors for transfusion included lower preoperative hemoglobin (p < 0.001), PJI indication (p = 0.008), and fracture indication (p = 0.02), with no difference for fracture greater or less than 4 weeks old (p = 0.53).

Conclusion

Risk factors for allogeneic red blood cell transfusion after SA were low preoperative hemoglobin and procedures for PJI or fracture.Level of Evidence: Level III, retrospective case-control study.