High incidence of periprosthetic joint infection with propionibacterium acnes after the use of a stemless shoulder prosthesis with metaphyseal screw fixation - a retrospective cohort study of 241 patients

Killing of a Multispecies Biofilm Using Gram-Negative and Gram-Positive Targeted Antibiotic Released from High Purity Calcium Sulfate Beads

BACKGROUND

Multispecies biofilm orthopedic infections are more challenging to treat than mono-species infections. In this in-vitro study, we aimed to determine if a multispecies biofilm, consisting of Gram positive and negative species with different antibiotic susceptibilities could be treated more effectively using high purity antibiotic-loaded calcium sulfate beads (HP-ALCSB) containing vancomycin (VAN) and tobramycin (TOB) in combination than alone.

METHODS

Three sets of species pairs from bioluminescent strains of Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA) and clinical isolates, Enterococcus faecalis (EF) and Enterobacter cloacae were screened for compatibility. PA + EF developed intermixed biofilms with similar cell concentrations and so were grown on 316L stainless steel coupons for 72 h or as 24 h agar lawn biofilms and then treated with HP-ALCSBs with single or combination antibiotics and assessed by viable count or bioluminescence and light imaging to distinguish each species. Replica plating was used to assess viability.

RESULTS

The VAN + TOB bead significantly reduced the PA + EF biofilm CFU and reduced the concentration of surviving antibiotic tolerant variants by 50% compared to single antibiotics.

CONCLUSIONS

The combination of Gram-negative and positive targeted antibiotics released from HP-ALCSBs may be more effective in treating multispecies biofilms than monotherapy alone.

Risk Factors for Periprosthetic Joint Infection after Shoulder Arthroplasty: Systematic Review and Meta-Analysis

Periprosthetic joint infection (PJI) after shoulder arthroplasty is a devastating complication that requires several additional surgeries. The purpose of this study was to assess the evidence regarding risk factors for PJI and identify those that contribute to infection by performing a meta-analysis. We searched the PubMed, Embase, and Cochrane Library databases for studies that assessed the risk factors for infection after shoulder arthroplasty. After performing screening and quality assessment on the articles, we obtained two case-control studies and six retrospective cohort studies (total of 420 infected cases and 28,464 controls). Review Manager 5.4 was used to assess the heterogeneity and odds ratio for 20 different factors that broadly included demographic factors, perioperative factors, and comorbidities. Factors that are markedly associated with PJI after shoulder arthroplasty were male sex, operation history, revision arthroplasty, acute trauma, and non-osteoarthritis as a preoperative diagnosis. Statistical analysis revealed that diabetes mellitus, liver disease, alcohol overuse, iron-deficiency anemia, and rheumatoid arthritis were risk factors for PJI after shoulder arthroplasty. The result of analysis shows that several specific factors can be targeted to prevent infections after shoulder arthroplasty. Surgeons should consider the risk factors and perform the appropriate management for patients.

Survival of stemless humeral head replacement in anatomic shoulder arthroplasty: a prospective study

BACKGROUND

The long-term results of shoulder arthroplasty using stemless humeral head components with a mean follow-up period > 10 years were not available until now. The aim of this study was to evaluate the long-term results of shoulder arthroplasty using a stemless humeral head component.

METHODS

Since 2005, we have documented stemless humeral head replacement prospectively. Seventy-five patients with a mean age of 57 years at surgery (40 hemi-shoulder arthroplasties [HSAs] and 35 total shoulder arthroplasties [TSAs], 38 women and 37 men) were clinically and radiologically followed up after a mean period of 126 months (range, 105-157 months). Functional results were documented using the age- and sex-normalized Constant-Murley score (CMS) (ie, relative CMS).

RESULTS

The relative CMS improved significantly (P < .0001) from 56% preoperatively to 90% postoperatively. Its subcategories of pain (8 points preoperatively vs. 12 points postoperatively, P < .0001), activities of daily living (10 points vs. 15 points, P < .0001), range of motion (20 points vs. 29 points, P < .0001), and strength (7 points vs. 11 points, P = .011) improved significantly as well. There was no significant difference in preoperative CMS vs. postoperative CMS, as well as its subcategories, between HSA (44.8 points vs. 67.1 points, P < .0001) and TSA (44.4 points vs. 68.9 points, P = .004). Clinically and radiologically, we observed no loosening of the stemless humeral head component. Stress shielding around the humeral component was not detected. Upward migration of the humeral head was observed in 17.5% of patients (21.6% with HSA and 11.5% with TSA, P = .303). No implant failure was observed on the humeral side. At follow-up, 18.3% of patients had rotator cuff deficiency (13.9% with HSA and 25% with TSA, P = .280). Overall, 9.3% of stemless shoulder arthroplasties were revised to reverse TSAs (5% of HSAs and 14.3% of TSAs, P = .097). TSA showed a trend for a higher revision rate than HSA. Secondary glenoid wear occurred in 64.3% of HSAs, and none of the HSAs were converted to TSAs. We observed an incomplete radiolucent line < 2 mm in 30.4% and glenoid loosening in 11.4% of cemented glenoid components. Kaplan-Meier analysis revealed a 10-year survivorship rate of 96.5% and an estimated 13-year survivorship rate of 90.1% for stemless humeral components.

CONCLUSION

Stemless humeral head replacement showed no loosening and a significant improvement in shoulder function after a mean period of 11 years. The long-term clinical and radiologic results as well as the survivorship of anatomic shoulder arthroplasty using a stemless humeral head implant are comparable to the long-term results of standard stemmed anatomic shoulder arthroplasty.

Results of stemless shoulder arthroplasty: a systematic review and meta-analysis

Stemless shoulder arthroplasty relies solely on cementless metaphyseal fixation and is designed to avoid stem-related problem such as intraoperative fractures, loosening, stress shielding or stress-risers for periprosthetic fractures.

Many designs are currently on the market, although only six anatomic and two reverse arthroplasty designs have results published with a minimum of two-year follow-up.

Compared to stemmed designs, clinical outcome is equally good using stemless designs in the short and medium-term follow-up, which is also the case for overall complication and revision rates.

Intraoperative fracture rate is lower in stemless compared to stemmed designs, most likely due to the absence of intramedullary preparation and of the implantation of a stem.

Radiologic abnormalities around the humeral implant are less frequent compared to stemmed implants, possibly related to the closer resemblance to native anatomy.

Between stemless implants, several significant differences were found in terms of clinical outcome, complication and revision rates, although the level of evidence is low with high study heterogeneity; therefore, firm conclusions could not be drawn.

There is a need for well-designed long-term randomized trials with sufficient power in order to assess the superiority of stemless over conventional arthroplasty, and of one design over another.

Cite this article: EFORT Open Rev 2021;6:35-49. DOI: 10.1302/2058-5241.6.200067

Stemless anatomic total shoulder arthroplasty: a systematic review and meta-analysis

BACKGROUND

Stemless anatomic total shoulder arthroplasty (TSA) is used in the treatment of osteoarthritis of the shoulder joint and other degenerative shoulder diseases. It has several proposed advantages over stemmed TSA including increased bone preservation, decreased operative time, and easier removal at revision.

METHODS

A systematic search was conducted using MEDLINE, Embase, PubMed, and CENTRAL (Cochrane Central Register of Controlled Trials) to retrieve all relevant studies.

RESULTS

The literature search yielded 1417 studies, of which 22 were included in this review, with 962 patients undergoing stemless TSA. Stemless TSA led to significant improvements in range of motion and functional scores in all included studies. Meta-analysis of comparative studies between stemless and stemmed TSA identified no significant differences in postoperative Constant scores (mean difference [MD], 1.26; 95% confidence interval [CI], -3.29 to 5.81 points; P = .59) or complication rates (odds ratio, 1.79; 95% CI, 0.71-4.54; P = .22). Stemless TSA resulted in a significantly shorter operative time compared with stemmed TSA (MD, -15.03 minutes; 95% CI, -23.79 to -6.26 minutes; P = .0008). Stemless TSA also resulted in significantly decreased intraoperative blood loss compared with stemmed TSA (MD, -96.95 mL; 95% CI, -148.53 to -45.36 mL; P = .0002).

CONCLUSION

Stemless anatomic TSA resulted in similar functional outcomes and complication rates to stemmed TSA with decreased operative time and lower blood loss. Further research is required to investigate the long-term durability of the stemless implant.

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

BACKGROUND

Cutibacterium are the most common cause of periprosthetic shoulder infections, as defined by ≥2 deep cultures. Established Cutibacterium periprosthetic infections cannot be resolved without prosthesis removal. However, the decision for implant removal must be made from an assessment of infection risk before the results of intraoperative cultures are finalized. We hypothesized that the risk for a Cutibacterium infection is associated with characteristics that are available at the time of revision arthroplasty.

METHODS

In a retrospective review of 342 patients having prosthetic revisions between 2006 and 2018 for whom definitive deep culture results were available, we used univariate and multivariate analyses to compare the preoperative and intraoperative characteristics of 101 revisions with Cutibacterium periprosthetic infections to the characteristics of 241 concurrent revisions not meeting the definition of infection.

RESULTS

Patients with definite Cutibacterium periprosthetic infections were younger (59 ± 10 vs. 64 ± 12, P < .001), were more likely to be male (91% vs. 44%, P < .001), were more likely to have had their index procedure performed for primary osteoarthritis (54% vs. 39%, P = .007), were more likely to be taking testosterone supplements (8% vs. 2%, P = .02), had lower American Society of Anesthesiologists scores (1.9 ± 0.7 vs. 2.3 ± 0.7, P < .001), and had lower body mass indices (29 ± 5 vs. 31 ± 7, P = .005). Patients with definite Cutibacterium periprosthetic infections also had significantly higher preoperative loads of Cutibacterium on their unprepared skin surface (1.7 ± 0.9 vs. 0.4 ± 0.8, P < .001) and were more likely to have the surgical finding of synovitis (41% vs. 16%, P < .001).

CONCLUSIONS

The risk of definite Cutibacterium periprosthetic infections is associated with observations that can be made before or at the time of revision arthroplasty.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

III, retrospective cohort study.

The short-term survival of total stemless shoulder arthroplasty for osteoarthritis is comparable to that of total stemmed shoulder arthroplasty: a Nordic Arthroplasty Register Association study

BACKGROUND

The purpose of this study was to compare the short-term survival rate of total stemless, metaphyseal fixated, shoulder arthroplasty with that of total stemmed shoulder arthroplasty in the treatment of osteoarthritis.

METHODS

Data were collected by the national arthroplasty registries in Denmark, Finland, Norway, and Sweden and merged into 1 dataset under the umbrella of the Nordic Arthroplasty Register Association. For the present study, we included all patients with osteoarthritis treated with either stemless (n = 761) or stemmed (n = 4398) shoulder arthroplasty from 2011 to 2016.

RESULTS

A total of 21 (2.8%) stemless and 116 (2.6%) stemmed shoulder arthroplasties were revised. The 6-year unadjusted cumulative survival rates were 0.953 for stemless shoulder arthroplasty and 0.958 for stemmed shoulder arthroplasty, P = .77. The most common indication for revision of both arthroplasty types was infection. Five (0.7%) stemless and 16 (0.4%) stemmed shoulder arthroplasties were revised because of loosening of either the glenoid or the humeral component. In the multivariate cox regression model, which included age, category, gender, year of surgery, previous surgery, and arthroplasty type, the hazard ratio (HR) for revision of the stemless shoulder arthroplasty was 1.00 (95% confidence interval [CI], 0.63-1.61), P = .99, with the stemmed shoulder arthroplasty as reference. Male gender (HR = 1.50 [95% CI, 1.06-2.13], P = .02) and previous surgery (HR = 2.70 [95% CI, 1.82-4.01], P < .001) were associated with increased risk of revision.

CONCLUSION

The short-term survival of total stemless shoulder arthroplasty appears comparable with total stemmed shoulder arthroplasty, but longer observation time is needed to confirm whether they continue to perform equally.

Challenging Diagnostics of Biofilm Associated Periprosthetic Infection in Immunocompromised Patient: A Clinical Case

BACKGROUND:

Periprosthetic joint infection (PJI) is a devastating complication of joint arthroplasty. The identification of microorganisms in biofilm-related PJI is challenging yet significant stage of the treatment process. Medical microbiology methods, such as pure culture isolation, remain the gold standard. However, the error rate of classical methods may vary from 10% to as high as 42% due to the inability to detect bacteria growing within biofilms. Other methods of detection are being explored to improve the management of PJI.

AIM:

Accurate identification of PJI contributing microorganisms in a patient with acute postoperative PJI after total hip joint arthroplasty and systemic lupus erythematosus in anamnesis.

METHODS:

We used microbial culture methods followed by scanning electron microscopy (SEM).

RESULTS:

Perioperative an intraoperative cultural analysis of 8 different culture samples of tissue and prosthetic origin was insufficient for bacterial or fungal detection. Scanning electron microscopy revealed detailed biofilm visualisation on the surface of the prosthetic component. The biofilm exterior was composed of microbial clusters made of 10 or more cells with either pear- or bottle-shaped morphology, 3-6 mcm in length and 1.5-3 mcm in diameter. Rod-shaped microorganisms of 0.7-1 mcm length and up to 0.5 mcm in diameter were found adjacent to these clusters.

CONCLUSION:

Additional methods for PJI agents’ detection are time-and cost-effective in the case of the challenging diagnostics of biofilm-related PJI, particularly in immunocompromised patients. Using combined diagnostic approaches increases the accuracy of detection, justifies treatment strategies and improves clinical outcomes.

Propionibacterium acnes Has Low Susceptibility to Chlorhexidine Digluconate

BACKGROUND

The skin bacterium Propionibacterium acnes has been reported to be responsible for surgical site infections (SSIs). Skin disinfection before surgery therefore is of the utmost importance in the prevention of SSIs caused by skin bacteria.

METHODS

We assessed the susceptibility of clinical isolates of two skin bacteria, P. acnes and Staphylococcus epidermidis, to disinfectants.

RESULTS

The range of chlorhexidine digluconate (CHG) minimum inhibitory concentrations (MICs) for P. acnes isolates was 0.25-1 mcg/mL. Furthermore, the minimum bactericidal concentrations (MBCs) for a range of disinfectants were determined to evaluate their rapid bactericidal activity. The MBC range of CHG against the P. acnes isolates was 4,096->32,768 mcg/mL (MBC₈₀ 16,384 mcg/mL) after one minute of exposure and 1,024-32,768 mcg/mL (MBC₈₀ 8,192 mcg/mL) after five minutes, indicating that some strains required a CHG MBC higher than the commercial concentration of 2% (20,000 mcg/mL). In contrast, the MBCs of glutaraldehyde, sodium hypochlorite, povidone-iodine, ethanol, benzalkonium chloride, and olanexidine gluconate were all sufficiently lower than their commercial concentrations. In S. epidermidis, the MBC range of CHG was 128-1,024 mcg/mL at one minute of exposure and 4-8 mcg/mL at five minutes.

CONCLUSIONS

Different skin bacteria have different susceptibilities to disinfectants. To prevent SSIs, the selected disinfectant agent and the disinfection time should have bactericidal activity toward all the bacteria that pose a risk of infection.