Does retained cement or hardware during 2-stage revision shoulder arthroplasty for infection increase the risk of recurrent infection?

BACKGROUND: When treating chronic prosthetic joint infection after shoulder arthroplasty, removal of the implants and cement is typically pursued because they represent a potential nidus for infection. However, complete removal can increase morbidity and compromise bone stock that is important for achieving stable revision implants. The purpose of this study is to compare the rates of repeat infection after 2-stage revision for prosthetic joint infection in patients who have retained cement or hardware compared to those who had complete removal. MATERIALS AND METHODS: We retrospectively analyzed all two-stage revision total shoulder arthroplasties performed for infection at 2 institutions between 2011 and 2020 with minimum 2-year follow-up from completion of the two-stage revision. Patients were included if they met the International Consensus Meeting criteria for probable or definite infection. Postoperative radiographs after the first-stage of the revision consisting of prosthesis and cement removal and placement of an antibiotic spacer were reviewed to evaluate for retained cement or hardware. Repeat infection was defined as either ≥2 positive cultures at the time of second-stage revision with the same organism cultured during the first-stage revision or repeat surgery for infection after the two-stage revision in patients that again met the International Consensus Meeting criteria for probable or definite infection. The rate of repeat infection among patients with retained cement or hardware was compared to the rate of infection among patients without retained cement or hardware. RESULTS: Thirty-seven patients met inclusion criteria and were included in the analysis. Six (16%) patients had retained cement and 1 patient (3%) had 2 retained broken glenoid baseplate screws after first-stage revision. Of the 10 cases of recurrent infection, 1 case (10%) involved retained cement/hardware. Age at revision (60.9 ± 10.6 vs. 65.0 ± 9.6, P = .264), body mass index (33.4 ± 7.2 vs. 29.7 ± 7.3, P = .184), Charlson Comorbidity Index (2 (0-8) vs. 3 (0-6), P = .289), male sex (7 vs. 16, P = .420), and presence of diabetes (1 vs. 3, P = .709) were not associated with repeat infection. Retained cement or hardware was also not associated with a repeat risk of infection (1 vs. 6, odds ratio = 0.389, P = .374). DISCUSSION: We did not find an increased risk of repeat infection in patients with retained cement or hardware compared to those without. Therefore, we believe that surgeons should consider leaving cement or hardware that is difficult to remove and may lead to increased morbidity and future complications.

Functional Composite Spacer (Antibiotic Cement around a Hemiarthroplasty) for the Treatment of Shoulder Infections: Minimum 5-Year Outcomes.

BACKGROUND: Periprosthetic infections remain a challenging complication following shoulder arthroplasty and an ideal treatment protocol has yet to be established. Two-stage revision is a common approach. Historically, the first stage entails placement of an all-cement antibiotic spacer. While prior studies have reported on cement spacers as definitive management, persistent pain and inadequate function often lead many to later request a second stage procedure. The functional composite spacer consists of a humeral hemiarthroplasty implant with antibiotic cement coated around the stem alone to preserve the metallic humeral head-glenoid articulation. Functional composite spacers have demonstrated improvements in function and motion with high patient satisfaction at 25 months, but longer-term follow-up is needed to better understand the role it may play in the management of shoulder infections. The purpose of this study is to evaluate outcomes at a minimum of 5 years in patients who initially planned to undergo two-stage revision but elected to retain the functional spacer. METHODS: A retrospective review of a single institution's shoulder surgery repository from 2007 to 2018 identified 30 patients who underwent placement of a composite spacer. Overall, 5 patients underwent second stage reimplantation and 12 patients did not have 5-year follow-up (6 lost to follow-up and 6 deceased). A total 13 patients were included who maintained a functional composite spacer and had minimum 5-year follow-up. Patient-reported outcome measures (ASES, SST, SANE, VAS F and VAS P), satisfaction, range of motion, and radiographic estimation of glenoid wear were evaluated. RESULTS: Two of 13 patients (15%) required additional surgery: one secondary closure for early superficial wound dehiscence and one revision spacer for pain. There were no re-infections. At most recent follow-up patient satisfaction was high and significant improvements were noted for ASES (45.4; p<0.001), SST (5.3; p=0.003), SANE (47.3; p=0.002), VAS F (4.9; p=0.004), and VAS P (-4.4; p=0.007) as well as range of motion including abduction (39.2˚; p=0.005) and elevation (65.9˚; p=0.005). There was no significant change in humeral head medialization (p=0.11). CONCLUSIONS: Patients who do not undergo an early revision and retain a functional composite spacer maintain good function and range of motion with minimal pain at mid-term follow-up.

High Incidence of Acute Kidney Injury Following Antibiotic-Loaded Spacer Insertion for Periprosthetic Joint Infection: An Updated Review of the Literature.

BACKGROUND: The use of antibiotic-impregnated cement during 2-stage revision arthroplasty for periprosthetic joint infection poses a risk of renal complications following spacer insertion. This systematic review aimed to investigate the rate of acute kidney injury (AKI) following antibiotic-loaded spacer insertion and to identify risk factors associated with this complication. METHODS: A systematic review was performed using PubMed, Cochrane Central, and Scopus databases. All clinical studies that documented renal complications following antibiotic-loaded spacer insertion for periprosthetic knee (total knee arthroplasty [TKA]) or hip (total hip arthroplasty [THA]) infection were included. Articles that combined THA and TKA outcomes were also included and labeled "THA + TKA." Descriptive statistics were analyzed when data were available. RESULTS: There were 24 studies (9 THA, 7 TKA, 8 THA + TKA) included. The mean incidences of spacer-related AKI across THA, TKA, and THA + TKA cohorts were 4.2 (range, 0 to 10%), 14 (range, 0 to 19%), and 27% (range, 0 to 35%), respectively. The most common patient-related risk factors for AKI were underlying chronic kidney disease or high baseline creatinine, low preoperative hemoglobin, and blood transfusion requirement. Spacer-related risk factors included high antibiotic dosage (>3.6 g/cement batch) and antibiotic type. While most recovered without complication, select patients required hemodialysis for acute management (2 THA, 18 THA + TKA) and/or developed chronic kidney disease (8 TKA, 8 THA). CONCLUSION: The rate of AKI following spacer insertion was high and likely under-reported in the literature. Surgeons should be cognizant of this devastating complication and should closely monitor at-risk patients for AKI following antibiotic-loaded spacer insertion.

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.

Modern Description of Antibiotic Spacer Options for PJI in Revision Total Knee Arthroplasty: Clinical Outcomes and Infection Eradication Rates.

BACKGROUND: As the burden of periprosthetic joint infections (PJIs) increases, there is growing interest in understanding the efficacy and morbidity reduction of 2-stage revision and various antibiotic spacer options. This study aimed to expand the description and evaluation of spacers from solely their articulation status to include their ability to support full (functional) or partial weight-bearing (nonfunctional). METHODS: Between 2002 and 2021, 391 patients who had Musculoskeletal Infection Society criteria for PJI with 1-stage or 2-stage revision were included. Demographics, functional outcomes, and subsequent revision data were collected. The study population had a mean follow-up of 2.9 years (range, 0.05-13.0) with an average age of 67 years (range, 34.7-93.4). Spacer failure was defined by surgical intervention following definitive surgery, and infection eradication was defined by the Delphi criteria. Spacers were classified as nonfunctional static, nonfunctional dynamic, functional static, or functional dynamic. Two tailed t-tests were performed. RESULTS: There were no significant differences in infection eradication or mechanical outcomes across spacer types; notably, 97.3% of functional dynamic spacers achieved infection eradication. Functional spacers had a longer time to the second stage procedure and a greater number of patients who had not been reimplanted. There was no difference in reoperation rates in nonfunctional versus functional spacers. CONCLUSION: Within this cohort, infection eradication and spacer exchange rates were noninferior among spacers. Functional spacers may allow for earlier return to daily living given the weight-bearing capability when compared to nonfunctional, without sacrificing clinical outcome.

High Rate of Intramedullary Canal Culture Positivity in Total Knee Arthroplasty Resection for Prosthetic Joint Infection.

BACKGROUND: Periprosthetic infection is a devastating complication following total knee arthroplasty. A 2-stage protocol often includes an interim antibiotic spacer with intramedullary (IM) dowels. However, the necessity of IM dowels has recently been challenged. Specifically, the data supporting bacterial colonization of the IM canal are limited and controversial. The purpose of this study was to identify the rate of positive IM cultures during resection arthroplasty in periprosthetic knee infection. METHODS: A total of 66 IM diaphyseal cultures were taken during resection arthroplasty from 34 patients diagnosed with periprosthetic knee infection. These IM cultures were taken from the femoral and tibial canals using separate sterile instruments. All patients had infected primary total knee arthroplasty implants at the time of resection. RESULTS: Thirty one percent (n = 21) of IM canal cultures in this study were positive from either the tibial or the femoral diaphysis at the time of resection arthroplasty. There were 18 of 21 (86%) of the positive IM canal cultures with concordant intraoperative joint cultures where the IM cultures matched the intraarticular cultures. CONCLUSION: With a 31% positive IM canal culture rate, this study confirms the logic of using IM dowels with an antibiotic spacer to treat periprosthetic knee infection. Since the failure of a 2-stage reimplantation is catastrophic, any attempt to provide additional local antibiotic delivery seems warranted. Since nearly one-third of our patients had positive IM cultures, this simple addition to an antibiotic spacer has the potential to improve 2-stage results. Claims supporting the elimination of IM dowels during resection arthroplasty seem ill-advised.

Retained Functional Antibiotic Hip Spacers Have High Rates of Stem Loosening, Subsidence, and Reoperation.

BACKGROUND: Functional antibiotic hip spacers for treatment of periprosthetic joint infection may be retained in patients deemed too sick for reimplantation, or who elect to forego additional surgery. Our aim was to characterize reoperations, modes of failure, and function outcomes in patients who have retained hip spacers. METHODS: We performed a retrospective review of 43 hips that underwent placement of an articulating hip spacer between January 1, 2014 and November 30, 2021. There were 28 hips that completed 2-stage exchange (TS group) and were reimplanted at mean 4 months (range, 2 to 10). The other 15 hips underwent planned spacer retention (RS group). Mean follow-up was 2.9 years (range, 1 to 6.1 years). The RS group was older (74 versus 66 years, P = .005) and had a higher age-adjusted Charlson Comorbidity Index (4.4 versus 3.3, P = .04) compared with the TS group. RESULTS: Overall survivorship free of reinfection was 91% at 1 year and 86% at 5 years. There were 6 RS hips that underwent reimplantation for spacer failure at a mean of 23 months (range, 6 to 71 months) and 8 had radiographic stem loosening/subsidence. Patients who had a retained spacer at final follow-up were more likely to require a walker (P = .005) or wheelchair (P = .049) compared with patients who underwent reimplantation. CONCLUSIONS: Retained hip spacers can decrease overall surgical burden, but are associated with high rates of stem loosening, subsidence, and unplanned reoperation. Planned spacer retention should be undertaken with caution in patients healthy enough to undergo reimplantation.

Outcomes after resection arthroplasty versus permanent antibiotic spacer for salvage treatment of shoulder periprosthetic joint infections: a systematic review and meta-analysis.

BACKGROUND: Although revision to new components is favored after shoulder periprosthetic joint infections (PJIs), implant exchange is not always feasible. In certain cases, definitive treatment may be retainment of an antibiotic spacer or resection arthroplasty. The purpose of this investigation was to systematically review the literature for studies reporting on outcomes after resection arthroplasty or permanent antibiotic spacer for salvage treatment of shoulder PJIs. METHODS: A systematic review was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials were searched for Level I-IV studies that reported on the final treatment of periprosthetic shoulder infections using resection arthroplasty or a permanent antibiotic spacer. Data recorded included study demographics, causative infectious organism, shoulder-specific range of motion and outcome measures, and infection eradication rate. Study methodological quality was analyzed using the Methodological Index for Non-Randomized Studies score. Forest plots of proportions and meta-analyses of single means were generated for infection eradication rates and outcomes, respectively. Heterogeneity was quantified using the I2 statistic. A P value of .05 was set as significant. RESULTS: The initial search yielded 635 articles (211 duplicates, 424 screened, 57 full-text review). Twenty-three articles (126 resection arthroplasty and 177 retained antibiotic spacer patients, 51% females, mean age range 37-78.5 years, mean Methodological Index for Non-Randomized Studies score 9.6 ± 0.7) were included and analyzed. The pooled infection eradication rate was 82% (72%-89%) after resection arthroplasty and 85% (79%-90%) after permanent antibiotic spacer. The pooled mean forward flexion (71.5° vs. 48.7°; P < .001) and mean American Shoulder and Elbow Surgeons score (53.5 vs. 31.0; P < .001) were significantly higher for patients treated with a permanent antibiotic spacer compared with resection arthroplasty. No significant differences were found for mean external rotation (13.5° vs. 20.5°; P = .07), abduction (58.2° vs. 50.3°; P = .27), or visual analog scale pain (3.7 vs. 3.4; P = .24) between groups. There was a statistically significant, but not clinically significant, difference in mean Constant score between permanent antibiotic spacer and resection arthroplasty patients (33.6 vs. 30.0; P < .001). CONCLUSION: When implant exchange after shoulder PJI is not feasible, permanent antibiotic spacers and resection arthroplasty are both salvage procedures that provide similar rates of infection eradication. Although both can decrease pain levels, the permanent antibiotic spacer may result in better functional outcomes compared with resection arthroplasty.

Does Time to Reimplantation After Explant for Prosthetic Joint Infection Influence the Likelihood of Successful Outcomes at 2 Years?

BACKGROUND: Consensus recommendations are lacking regarding appropriate timing of reimplantation following 2-stage resection arthroplasty for prosthetic joint infections (PJIs). We investigated whether the time from resection arthroplasty to reimplantation was associated with treatment outcome at 2 years. METHODS: Retrospective cohort review was conducted for 101 patients undergoing resection arthroplasty with an antibiotic spacer for PJI at a single tertiary academic referral institution. Time from explantation and spacer placement to reimplantation was categorized into 3 groups: <12, 12-18, and >18 weeks. Baseline patient and treatment course characteristics across these groups were obtained. Multivariate binary logistic regression was used to characterize association between treatment failure and time to reimplantation, controlling for American Society of Anesthesiologists (ASA) score and prior revision surgery. RESULTS: Time to reimplantation (TTR) >18 weeks demonstrated statistically significant increased odds of treatment failure, after controlling for ASA score and prior revision surgery (odds ratio 7.00, confidence interval 2.14-25.42, P = .002). After excluding patients requiring second spacer or Girdlestone prior to replant, this increased odds of failure remained (odds ratio 4.12, confidence interval 1.18-15.37, P = .029). TTR groups were similar with respect to demographics, except for ASA (2.96 for time to reimplantation >18 weeks vs 2.55 for time to reimplantation <12 weeks; P = .011). Patients with TTR >18 weeks were more likely to have an unplanned readmission during the spacer period (48%, 19%, and 6% for time to reimplantation >18, 12-18, and 0-12 weeks, respectively; P < .002). CONCLUSION: Although decision regarding TTR is largely patient specific, surgeons should be aware that TTR >18 weeks may be associated with higher rates of treatment failure at 2 years.

High-Dose Antibiotic Cement Spacers Independently Increase the Risk of Acute Kidney Injury in Revision for Periprosthetic Joint Infection: A Prospective Randomized Controlled Clinical Trial.

BACKGROUND: Standard treatment for periprosthetic joint infection (PJI) involves 2-stage exchange with placement of an antibiotic-impregnated cement spacer (ACS). Conflicting evidence exists on the role of ACS in development of acute kidney injury (AKI) after first-stage surgery. In this randomized clinical trial, we aimed to compare the incidence of AKI between the first-stage of a planned 2-stage exchange vs 1-stage exchange. This study design isolates the effect of the ACS in otherwise identical treatment groups. METHODS: The primary outcome variable was AKI, defined as a creatinine ≥1.5 times baseline or an increase of ≥0.3 mg/dL. Risk factors for AKI were evaluated using bivariate statistical tests and multivariable logistic regression. RESULTS: Patients who underwent the first stage of a planned 2-stage exchange were significantly more likely to develop AKI compared with the 1-stage exchange group (15 [22.7%] vs 4 [6.6%], P = .011). On multivariable regression analysis, ACS placement (odds ratio 7.48, 95% confidence limit 1.77-31.56) and chronic kidney disease (odds ratio 3.84, 95% confidence limit 1.22-12.08) were independent risk factors for AKI. CONCLUSION: Our study provides evidence that high-dose antibiotic cement spacers for treatment of PJI are an independent risk factor for AKI. Therefore, efforts to minimize nephrotoxicity should be employed in revision for PJI when possible.

Clinical Outcomes After Stage-One Antibiotic Coated Molded Hip Spacer.

BACKGROUND: Two-stage exchange remains the gold standard for managing periprosthetic joint infection (PJI). We evaluated the outcomes of patients treated with a specific molded articulating antibiotic hip spacer for PJI at a tertiary referral center. METHODS: An institutional database was retrospectively queried for patients who underwent implantation of spacer between 2009-2019. Patient demographics and clinical outcomes were collected. RESULTS: We identified 88 patients at an average age of 60.4 years who received a spacer implant, with an average of 4.2 years follow-up (standard deviation [SD] 2.5 years). A total of 34 patients (38.6%) had a "clean" two-stage course with successful reimplantation and no evidence of infection at 1-year follow-up. The remaining patients (61.4%) required 3.67 (±0.52) additional surgeries. Overall reimplantation rate was 72%. Causative bacterial agents included MSSA (n = 22), MRSA (n = 16), coagulase-negative Staphylococcus (n = 14), and polymicrobial (n = 12). Regarding complications, there were 13 (15%) dislocations, 16 (18%) periprosthetic fractures, 8 (9%) bent/fractured stems, and 16 (18%) patients had clinically significant subsidence. Patients with previous extended trochanteric osteotomy (ETO) experienced higher rates of bent/broken spacer stems (25% vs 3.1%; P = .006) periprosthetic fractures (37.5% vs 10.9%; P = .010), and dislocations (37.5% vs 6.2%; P = .001). The rate of infection clearance was lower in the prior ETO cohort (26.6% vs 54.2%; P = .029). CONCLUSION: We report outcomes in patients who underwent implantation of a specific molded articulating hip spacer at our institution. Infection eradication was roughly in line with published series of hip PJI treatment. There was a high rate of mechanical complications, especially in those patients who required an ETO.

In vitro elution characteristics of gentamicin-impregnated Polymethylmethacrylate: premixed with a second powder vs. liquid Lyophilization.

BACKGROUND: Antibiotic-loaded bone cement, or antibiotic-impregnated polymethylmethacrylate (PMMA), were developed to prevent and treat bone and joint infections. Gentamicin is an antibiotic that is commonly used in combination with PMMA; however, gentamicin powder is hard to obtain in many countries. This study aimed to evaluate the elution characteristics of gentamicin-impregnated PMMA made with lyophilized liquid gentamicin, compared with PMMA; which is made from commercial gentamicin powder. METHODS: The experimental sample was divided into 2 groups: the gentamicin power group (PG-PMMA) and the lyophilized liquid gentamicin group (LG-PMMA). Ten cement spacers were prepared in each group. These were produced by mixing gentamicin powder, or lyophilized liquid gentamicin, with a powder polymer before adding the liquid monomer (2 g of gentamicin and 40 g of PMMA). The volume and surface area of the antibiotic-impregnated cement spacers were 50 cm3 and 110 cm2, respectively. Each spacer was immersed in phosphate-buffered saline, which was changed daily under sterile conditions. The solutions were collected to measure the level of gentamicin using the enzyme multiplied immunoassay technique (EMIT), at days 1, 2, 3, 4, 5, 6, 7, 14, 21, 28, 35 and 42. RESULTS: The collections from both groups had high concentrations of gentamicin on day 1 (113.63 ± 23.42 mg/dL in LG-PMMA and 61.7 ±8.37 mg/dL in PG-PMMA), but experienced a continuous decrease over time. The PMMA spacers from both groups could release gentamicin for up to 6 weeks (3.28 ± 1.17 mg/dL in LG-PMMA and 1.21 ± 0.28 mg/dL in PG-PMMA). However, there were significantly higher levels of gentamicin concentrations in the LG-PMMA group compared to the PG-PMMA group at all time points (P< 0.05). CONCLUSION: Gentamicin-impregnated PMMA made with lyophilized liquid gentamicin had approximately a two times higher rate of antibiotic elution in preliminary in vitro studies, as compared with PMMA made with premixed gentamicin powder.

Temporary new implant spacers increase post-reimplantation total knee prosthesis survival after periprosthetic joint infection.

PURPOSE: Two-stage exchange arthroplasty is considered the gold standard for treatment of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA). Antibiotic cement spacers can include cement-based spacers (CBS), new components (NEW), and autoclaved components (ACL). The factors that most influence post-reimplantation prosthesis (PRP) survival were determined. METHODS: A retrospective database review of patients undergoing two-stage exchange arthroplasty from 2008 to 2014 was performed. There were 85 patients, 25 patients and 30 patients in CBS, NEW and ACL groups, respectively. Patient, disease and surgical characteristics were collected and analyzed. Post-reimplantation prosthesis (PRP) survival was modeled using the Kaplan-Meier method. Cox proportional hazard modeling was then performed to identify risk factors associated with implant failure. RESULTS: Overall PRP survival was 82% in 140 unilateral TKAs. PRP survival between groups was 81%, 96% and 73% within the minimum 2-year follow-up period, respectively. There was a difference in median interval-to-reimplantation between groups (CBS, 72.0 days; NEW, 111.0 days; ACL, 84.0 days, p = 0.003). Adjusting for time-to-reimplantation, NEW spacers demonstrated greater PRP survival compared with ACL spacers (p = 0.044), and a trend towards greater survival compared with CBS spacers (p = 0.086). Excluding early failures (< 90 days), NEW spacers still demonstrated greater survival than ACL spacers (p = 0.046). Lower volume (≤ 10 within this series) surgeons tended to use more CBS spacers, while higher volume surgeons were comfortable with ACL spacers. CONCLUSIONS: There was greater PRP survival with NEW spacers. NEW spacers also demonstrated an increased inter-stage interval, likely because of increased comfort and motion. There were spacer choice differences between low- and high-volume surgeons. LEVEL OF EVIDENCE: III.

Spacers for life: high mortality rate associated with definitive treatment of shoulder periprosthetic infection with permanent antibiotic spacer.

BACKGROUND: Periprosthetic joint infection following shoulder arthroplasty represents a challenging problem for orthopedic surgeons. Although recent studies have supported 2-stage exchanges, this treatment choice may not be appropriate for all patients. Definitive antibiotic spacer placement represents one treatment strategy with limited reported outcomes in the literature. The purpose of this study was to investigate the mortality rate and functional outcomes associated with definitive spacer placement. METHODS: A retrospective chart review identified 17 patients who were treated with definitive antibiotic spacer placement (18 spacers) and were followed up for a minimum of 2 years after surgery. The mortality rate over the study period was determined. Demographic information, clinical course, patient-reported outcomes (American Shoulder and Elbow Surgeons score, Single Assessment Numeric Evaluation score, and Veterans RAND 12 [VR-12] score), infection parameters as defined by International Consensus Meeting criteria, radiographic evaluation findings, and rotator cuff integrity at the time of spacer placement were collected. RESULTS: Seventeen patients underwent treatment with retained antibiotic spacers at a mean age of 62.4 years (range, 50-73 years). Ten patients were women, and the mean body mass index was 30.5 (range, 22.9-39.9). Spacer placement occurred at a mean of 6.1 years (range, 0.48-14.9 years) following index arthroplasty. Five patients required spacer exchange. The most common organisms were Cutibacterium acnes (6) and methicillin-sensitive Staphylococcus aureus (6); in addition, methicillin-resistant S aureus (2), coagulase-negative Staphylococcus (2), Serratia marcescens (1), gram-positive cocci (1), Enterobacter faecalis (1), Enterobacter cloacae (1), diphtheroids (1), and an infection with negative culture findings (1) were observed. The mortality rate was 52.9% (9 of 17 patients). Among the 8 surviving patients, the mean American Shoulder and Elbow Surgeons score was 33.9 (range, 13.3-80.0), the mean Single Assessment Numeric Evaluation score was 35.6 (range, 0.0-80.0), the mean VR-12 mental score was 57.2 (range, 36.6-66.9), and the mean VR-12 physical score was 37.1 (range, 21.7-64.0) at a mean of 4.7 years (range, 2.0-8.8 years). CONCLUSION: Definitive antibiotic spacer placement is an acceptable method to treat infection in medically frail patients who have a high mortality risk. Spacer exchange may be necessary because of persistent infection, and functional results are poor.

Antibiotic cement spacer retention for chronic shoulder infection after minimum 2-year follow-up.

HYPOTHESIS: The treatment of periprosthetic shoulder infections and proximal humerus osteomyelitis is challenging. The outcomes of antibiotic cement spacer retention are poorly defined in the literature. The purpose of this study was to review long-term functional and patient-reported outcomes data of patients with retained antibiotic cement spacers. We predict reasonable functional outcomes and minimal pain. METHODS: We identified 22 patients of the senior author who have been treated with definitive antibiotic spacer placement. All patients were originally offered a 2-stage revision and declined. Twelve patients had a minimum follow-up of 2 years and were included in our cohort. Mean age was 70.7 (range 59-81), 8/12 patients were female, and the average body mass index was 27.8 (range = 17-45). Functional outcome assessments included the Standardized Shoulder Assessment Form, the Quick Disabilities of the Arm, Shoulder, and Hand Score (QuickDASH), and visual analog scale (VAS) along with clinical range of motion examination. RESULTS: The patients were followed up for a mean of 5.6 years. Eight patients had spacer placement for chronic shoulder arthroplasty infections, whereas 4 patients had spacer placement for chronic osteomyelitis of the proximal humerus. No patients were currently being treated with suppressive antibiotics. One patient had negative cultures at the time of antibiotic spacer placement. The most common organisms were Cutibacterium acnes (6), Staphylococcus epidermidis (6), and methicillin-resistant Staphylococcus aureus (4), with 4 patients growing more than 1 species. The average ASES score was 54 (range = 27-73), QuickDASH was 45 (range = 14-89), and VAS score 2.8 (range = 0-8). Average active range of motion was 68° of forward elevation and 35° of external rotation. CONCLUSIONS: Retention of antibiotic cement spacer is a viable option in the treatment algorithm for chronic shoulder infections. Long-term antibiotic cement spacer may be considered for those patients who are unwilling or unable to undergo a 2-stage revision. Patients can expect a reasonable amount of function and little to no pain with an antibiotic cement spacer.

Point/Counterpoint: Static vs Articulating Spacers-Static Spacers for Resection Arthroplasty of the Knee.

Antibiotic spacers play a significant role in the treatment of periprosthetic joint infections. They help maintain soft-tissue tension and provide delivery of high dose of antibiotics to the local tissue. The use of static or dynamic spacers is based on multiple factors including the extent of soft-tissue, ligamentous and bone compromise, overall patient function, comorbid conditions, and virulence of the organism. There is no difference in reinfection incidence between static vs dynamic spacers following two-stage reimplantation. Static spacers can be customized to treat all cases of periprosthetic total knee infections and offer intraoperative flexibility to vary the cement quantity and amount of antibiotics in the spacer to provide high-dose local delivery of antibiotics to address the dead space, bone loss, and soft-tissue compromise. Static spacers are especially advantageous in cases of extensor mechanism and ligamentous compromise where articulating spacers may not be able to provide adequate stability.

Point/Counterpoint: Nonarticulating vs Articulating Spacers for Resection Arthroplasty of the Knee or Hip.

Two-stage exchange arthroplasty remains the gold standard for chronic total knee arthroplasty (TKA) and total hip arthroplasty infections in North America. Cement spacers impregnated with high-dose antibiotics have been successfully used in the interim period of the 2-stage exchange process. A number of spacers have been described; however, this article will focus on articulating spacers. In the presence of an intact extensor mechanism (for TKA), reasonable soft tissue envelope, and adequate bone, articulating antibiotic spacers provide several advantages. These include an infection eradication rate of approximately 90%, higher range of motion after reimplantation, and lower complication rates when compared with nonarticulating spacers. In the appropriate patient, articulating antibiotic spacers are an effective and a safe treatment for infected TKAs and total hip arthroplasties.

Do Antibiotic-Impregnated Intramedullary Dowels Assist in Eradicating Infection in Total Knee Arthroplasty?

Antibiotic-impregnated intramedullary dowels historically have been advocated and are frequently used to facilitate periprosthetic knee infection eradication. They are used for focused delivery of antibiotics into the femoral and tibial intramedullary canals during 2-stage resection utilizing an antibiotic cement spacer. However, the literature is limited on the use and efficacy of antibiotic-eluding intramedullary dowels in periprosthetic joint infection. We reviewed the available literature and have found that the data at this point are equivocal with respect to whether antibiotic-impregnated cement intramedullary dowels augment the intra-articular antibiotic cement spacer in eradicating infection in total knee arthroplasty. Thus, we believe that the decision to use dowels can be left up to the surgeon preference. However, further research is warranted to review operative room efficiency and healthcare costs, and to validate the clinical efficacy of antibiotic-impregnated dowels in periprosthetic joint infection.

Destination Joint Spacers, Reinfection, and Antimicrobial Suppression.

In this cohort of 51 patients managed with retained "destination spacers" after the resection of infected joint prostheses, the presence of preoperative sinus drainage was significantly associated with reinfection. Chronic antimicrobial suppression after destination-spacer retention did not significantly prevent reinfections.

Do Antibiotic Intramedullary Dowels Assist in Eradicating Infection in Two-Stage Resection for Septic Total Knee Arthroplasty?

BACKGROUND: Evidence suggests approximately 40% of intramedullary (IM) canals are culture positive at resection for infected knee arthroplasty. While commonly utilized, no clinical data on the efficacy of antibiotic-eluding IM dowels exist. We quantified treatment success with and without the use of antibiotic-eluding IM dowels in two-stage treatment of periprosthetic knee infection using static and articulating antibiotic cement spacers. METHODS: 109 consecutive patients who underwent two-stage treatment for periprosthetic knee infection were reviewed. Treatment failure, defined as repeat resection before reimplantation or recurrent infection within 6 months of reimplantation, was evaluated based on spacer type and use of IM dowels, accounting for infection type and systemic host and local extremity grade. RESULTS: After exclusions for confounds, articulating spacers without IM dowels were used in 49 (57.7%) cases, articulating spacers with IM dowels in 14 cases (16.5%), and static spacers with IM dowels in 22 (25.9%) cases. Treatment success regardless of infection classification was 85.7% for articulating spacers with IM dowels, 89.8% for articulating spacers without IM dowels, and 68.2% for static spacers with IM dowels (P = .074). In chronically infected poor hosts with compromised extremities, treatment success remained highest in patients with articulating spacers with (90.9%) or without (92.9%) IM dowels compared with static spacers with IM dowels (68.4%) (P = .061). CONCLUSION: Findings suggest that the use of IM dowels did not enhance infection eradication above and beyond that observed for articulating spacers alone, including in the worst cases involving chronically infected poor hosts with compromised extremities.