Reporting Outcomes of Treatment for Periprosthetic Joint Infection of the Knee and Hip Together With a Minimum 1-Year Follow-Up is Reliable

Rethinking Repeat Two-Stage Knee Exchange Arthroplasty: Outcomes, Risks, and Decision-Making

BACKGROUND

Chronic periprosthetic joint infection (PJI) presents a major challenge in knee arthroplasty, with varying success rates reported for two-stage exchange arthroplasty (EA) and a lack of consensus on managing failures from such procedures. This study evaluated repeat two-stage EA outcomes for knee PJI after initial treatment failure to identify the risk factors for reimplantation unsuitability and reinfection.

METHODS

We analyzed 114 patients who underwent repeat EA for chronic knee PJI between 2010 and 2018. From an initial cohort of 1,351 patients, we excluded 231: 18 for incomplete records or protocol non-compliance and 213 for prior revisions. Among the remaining 1,119 patients, 150 experienced reinfection. After excluding 36 who did not undergo repeat EA, the final cohort comprised 114 patients. Outcomes were evaluated using Delphi-based consensus success criteria as follows: healed wounds, no further infection interventions, and no PJI-related mortality.

RESULTS

In our study, 34.2% of the patients did not proceed with reimplantation due to reinfection or ongoing infection, which was influenced by factors such as high Charlson Comorbidity Index scores, recurrence of a microorganism, and shorter intervals between initial arthroplasty and reinfection. Among the reimplanted patients, 44.0% underwent further revision for rereinfection. Kaplan-Meier analysis of 1,119 initial, 75 repeat, and 24 re-repeat two-stage cases revealed 5-year infection-free survival rates of 93, 72, and 43%, respectively. This study identified significant reinfection risks in patients who have repeated infections by the same microorganisms, persistent PJI, or multiple spacer redo procedures. A 39.5% rereinfection rate, including 12 amputations and a 15.8% mortality rate, was observed in this series.

CONCLUSIONS

This study underscores the effectiveness of first-time two-stage EA for knee PJI and notes the challenges and lower success rates of subsequent attempts. This emphasizes the importance of identifying high-risk patients for tailored treatment plans and setting realistic expectations of outcomes.

LEVEL OF EVIDENCE

III.

Association between IV and topical tranexamic acid use and periprosthetic joint infections in hip and knee arthroplasty: a retrospective study

BACKGROUND

Anemia and blood transfusions are recognized as risk factors for periprosthetic joint infections (PJI). Tranexamic acid (TXA) is established in reducing perioperative blood loss and transfusion requirements. Our study investigates the impact of perioperative TXA administration on the incidence of PJI in patients undergoing total joint arthroplasty (TJA) and evaluates the association of intravenous (IV) and topical applications with PJI occurrence.

METHODS

A retrospective review was performed on 8042 patients who underwent primary total hip arthroplasty (THA) and knee arthroplasty (TKA) from January 2009 to December 2020, with a minimum one-year follow-up at our institution. We compared patients who received TXA (n = 3664, with 2345 receiving it IV and 1319 topically) to those who did not (n = 4378). 0.5-1.25 g of IV TXA was administered before skin incision, and 1.5-3 g of topical TXA was injected intra-articularly or into the drainage tube during surgery. The primary outcome was PJI development within one year, defined by the 2013 International Consensus Meeting criteria. Secondary outcomes included blood transfusion, hospital length of stay (LOS), venous thromboembolism (VTE), and 90-day readmission. We employed multivariate logistic regression and propensity score weighting to adjust for potential confounders and conducted subgroup analyses to assess PJI odds in TKA and THA patients treated with IV and topical TXA.

RESULTS

The TXA group demonstrated a lower PJI occurrence (1.1% vs. 2.1%, p < 0.001), less blood transfusion (14.4% vs. 22.7%, p < 0.001) and shorter LOS (5.6 ± 1.6 vs. 6.5 ± 2.5, p < 0.001) compared to those without TXA. There was no difference between the two groups with regards to VTE and 90-day readmission. Perioperative TXA administration demonstrated lower PJI in multivariate analysis (OR 0.54, 95% CI 0.36-0.80, p = 0.002), and in propensity score weighting (OR 0.53, 95% CI 0.36-0.80, p = 0.002). In the subgroup analysis, both IV and topical administration of TXA resulted in decreased PJI (IV group: OR 0.53, 95% CI, 0.33-0.84, p = 0.007, topical group: OR 0.51, 95% CI, 0.29-0.89, p = 0.018), especially in primary TKA (IV TXA, OR 0.49, 95% CI, 0.29-0.83, p = 0.008; Topical TXA, OR, 0.56, 95% CI, 0.32-0.98, p = 0.042).

CONCLUSION

Perioperative TXA administration in primary hip and knee arthroplasty is significantly associated with a reduced PJI occurrence. Both IV and topical TXA routes showed similar association with reduced PJI occurrence, with a notable correlation observed in primary TKA.

Predicting periprosthetic joint infection: external validation of preoperative prediction models

Introduction: Prediction models for periprosthetic joint infections (PJIs) are gaining interest due to their potential to improve clinical decision-making. However, their external validity across various settings remains uncertain. This study aimed to externally validate promising preoperative PJI prediction models in a recent multinational European cohort. Methods: Three preoperative PJI prediction models - by Tan et al. (2018), Del Toro et al. (2019), and Bülow et al. (2022) - that have previously demonstrated high levels of accuracy were selected for validation. A retrospective observational analysis of patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) at centers in the Netherlands, Portugal, and Spain between January 2020 and December 2021 was conducted. Patient characteristics were compared between our cohort and those used to develop the models. Performance was assessed through discrimination and calibration. Results: The study included 2684 patients, 60 of whom developed a PJI (2.2 %). Our cohort differed from the models' original cohorts with respect to demographic variables, procedural variables, and comorbidity prevalence. The overall accuracies of the models, measured with the c  statistic, were 0.72, 0.69, and 0.72 for the Tan, Del Toro, and Bülow models, respectively. Calibration was reasonable, but the PJI risk estimates were most accurate for predicted infection risks below 3 %-4 %. The Tan model overestimated PJI risk above 4 %, whereas the Del Toro model underestimated PJI risk above 3 %. Conclusions: The Tan, Del Toro, and Bülow PJI prediction models were externally validated in this multinational cohort, demonstrating potential for clinical application in identifying high-risk patients and enhancing preoperative counseling and prevention strategies.

Comparison of Delphi Consensus Criteria and Musculoskeletal Infection Society Outcome Reporting Tool Definitions of Successful Surgical Treatment of Periprosthetic Knee Infection

BACKGROUND

Agreement on success following surgical treatment for periprosthetic joint infection (PJI) is important for comparing the efficacy of different surgical approaches with varying consequences and outcomes and setting patient expectations. We compared success rates following two-stage exchange arthroplasty for knee PJI using two expert-consensus definitions of success.

METHODS

Prospectively documented data for 57 knees treated by a single surgeon at an academic tertiary care center were retrospectively reviewed. Treatment outcomes were quantified using the Delphi Consensus Criteria and the Musculoskeletal Infection Society Outcome Reporting Tool (MSIS ORT).

RESULTS

Success rates were 81% using the Delphi Consensus Criteria and 56% using the MSIS ORT (P = .008). The MSIS ORT success rates increased to 76% when aseptic revisions and deaths unrelated to PJI were not penalized as failures of treatment. Predicted probabilities of successful treatment in a hypothetical case scenario were lowest based on the MSIS ORT and similarly higher using Delphi Consensus Criteria and MSIS ORT modified for both women (53.0, 90.8, and 88.7%) and men (29.1, 89.1, and 89.3%).

CONCLUSIONS

Study observations underscore the need for a uniformly accepted single definition of surgical treatment success.

Do Organism Profile and Resistance Patterns Change between First and Subsequent Two-Stage Revision for Periprosthetic Joint Infection?

Increasing antibiotic resistance has been reported as an issue in the treatment of periprosthetic joint infection (PJI). A repeat two-stage revision for recurrent PJI is at high risk of reinfection. However, it is unclear if the microorganism profile plays a role with potentially more resistant or polymicrobial infections. This is a retrospective, single-center analysis of two-stage revisions performed between 2011 and 2017. We identified 46 patients who underwent a repeat resection arthroplasty for recurrent PJI of the same joint after a previous two-stage revision of the same joint at the same department. All microbiological findings were analyzed focusing on microbiological spectrum and resistance testing as well as the potential impact on reinfection-free survival. The most common organism found at the time of recurrent PJI were coagulase-negative Staphylococci (39%) followed by Gram-negative organisms (28%). The risk of polymicrobial infections, difficult-to-treat resistant organisms, and Gram-negative infections increased significantly. Among staphylococcal infections, there was a high percentage of methicillin-resistant species and resistance to oral antibiotics. Patients with Gram-negative organisms had a reduced infection-free survivorship, while resistant organisms were not associated with decreased survival. Patients who undergo a repeat two-stage revision for recurrent PJI have more polymicrobial and resistant organisms, although the impact on survivorship is unclear.

The Impact of Culture Negativity on the Outcomes of Revision Total Knee Arthroplasty for Chronic PJI

Culture-positive (CP) and culture-negative (CN) periprosthetic joint infections (PJI) remain a crucial area of research; however, current studies comparing these infections rely on unstandardized outcome reporting tools. Our study aimed to compare the outcomes of two-stage revision of CP and CN PJI using the standardized Musculoskeletal Infection Society (MSIS) outcome reporting tool. We retrospectively reviewed 138 patients who were diagnosed with PJI and indicated for two-stage revision total knee arthroplasty (rTKA). The majority of patients in both CP and CN cohorts achieved infection control without the need for reoperation (54.1% and 62.5%, respectively). There was a significant difference in the overall distribution of MSIS outcomes (p = 0.043), with a significantly greater rate of CN patients falling into Tier 1 (infection control without the use of suppressive antibiotics) (52.5% versus 29.6%, p = 0.011). There was also a significant difference in the distribution of septic versus aseptic reoperations after 2nd stage (p = 0.013), with more CP reoperations being septic and more CN reoperations being aseptic. The duration from first to second stage was significantly shorter in the CN cohort (p = 0.002). While overall infection control was similar between cohorts, these data suggest that the outcomes of two-stage rTKA are favorable in cases of CN PJI.

Mouldable Collagen-Tricalciumphosphate Is a Safe Carrier for Local Antibiotics-Short-Term Results in Revision Hip Arthroplasty

BACKGROUND

Improving local antibiotic delivery is a promising approach to improve infection control and potentially shorten systemic treatment in periprosthetic joint infection (PJI). This study investigates the use of an antibiotic-loaded, mouldable collagen-tricalciumphosphate composite in treatment of hip PJI.

METHODS

124 application cases in 79 patients were included from a referral centre; systemic adverse infects, local complications, and infection control were analysed.

RESULTS

In most cases, either vancomycin or meropenem were used. Pathogens were previously known in 82 (66%) cases with polymicrobial infection in 20 (25%) patients. There were no cases of hypercalcaemia. Acute kidney injure was present in 14 (11%) cases. Chronic kidney failure persisted in two cases. During a mean follow-up of 12 (SD 9.3; range 3-35) months, implant survival was achieved in 73 (92%) patients; revision due to PJI was performed in 19 cases.

CONCLUSION

Mouldable collagen-tricalciumphosphate composite bone substitute as a local antibiotic carrier in revision hip arthroplasty appears to be a valid option for local antibiotic delivery without systemic complications. Implant survival of 92% supports the hypothesis that local antibiotic therapy is an important component in the treatment of PJI.

The microbial profile of infected endoprosthetic reconstructions after wide excision for patients with musculoskeletal tumors: A call for pathogen-based practices

BACKGROUND AND OBJECTIVES

Periprosthetic infection is a devastating complication following endoprosthetic reconstruction. This study utilized a large database of endoprostheses to describe the incidence, risk factors, and microbial profile of such infections to better catalogue and understand these catastrophic events.

METHODS

A retrospective review of endoprosthetic reconstructions for an oncologic indication from January 1, 1981 to December 31, 2020 was performed. Demographic, oncologic, procedural and outcome data was analyzed. Multivariable logistic regression was used to identify potential risk factors for infection with significance defined as p < 0.05.

RESULTS

Forty four out of 712 (6.2%) reconstructions resulted in infection at a mean time of 39.9 ± 44.5 months. Revision surgery (odds ratio [OR] 6.14, p < 0.001) or having a postoperative wound complication (OR 7.67, p < 0.001) were significantly associated with infection. Staphylococcus aureus and Staphylococcus epidermidis were the most commonly cultured organisms at a rate of 34.1% (15/44) and 22.7% (10/44), respectively. Ten infections resulted in amputation; five due to antimicrobial-resistant infections and three due to polymicrobial infections.

CONCLUSION

Understanding the microbial profile of patients undergoing endoprosthetic reconstruction is paramount. This study demonstrates a relatively high rate of polymicrobial and antibiotic-resistant infections that portend worse outcomes, thus suggesting that pathogen-specific infectious practices may be warranted.

LEVEL OF EVIDENCE

Retrospective cohort study, level III.

Two-Stage Exchange Using a Total Femur Spacer in the Management of Periprosthetic Joint Infection - Spacer Complications and Implant Survivorships

BACKGROUND

Chronic periprosthetic joint infection after revision hip and knee arthroplasties can lead to subsequent massive femoral bone loss. In these cases, resection of the residual femur and placement of an antibiotic total femoral spacer can be an option to salvage the limb.

METHODS

This is a single-center retrospective analysis of 32 patients (median age 67 years; range 15-93; 18 women) who underwent placement of a total femur spacer for chronic periprosthetic joint infection with massive femoral bone loss between 2010 and 2019 as part of a planned two-stage exchange. The median follow-up period amounted to 46 months (range, 1-149). Implant and limb survival were analyzed using Kaplan-Meier survival estimates. Potential risk factors for failure were analyzed.

RESULTS

There were 34% (11 of 32) of patients having a spacer-associated complication, and 25% underwent revision for this reason. After the first stage, 92% were considered infection-free. There were 84% of patients who underwent second-stage reimplantation of a total femoral arthroplasty using a modular megaprosthetic implant. Infection-free implant survival was 85% after 2 years and 53% after 5 years. There were 44% of patients who underwent amputation after a median time of 40 months (range, 2-110). Most commonly, coagulase-negative staphylococci were cultured at first-stage surgery, while polymicrobial growth was most common at reinfection.

CONCLUSION

Total femur spacers can lead to infection control in over 90% of cases with a reasonable complication rate for the spacer itself. However, the reinfection and subsequent amputation rate after second-stage megaprosthetic total femoral arthroplasty is around 50%.

Good Mid-Term Implant Survival of a Novel Single-Design Rotating-Hinge Total Knee Arthroplasty

BACKGROUND

Rotating-hinge knee (RHK) implants are an option for knee arthroplasty in cases of instability or severe bone loss. However, the revision rate can be increased compared to unconstrained implants which mandate improvements in implant design. This study investigates a novel RHK design for total knee arthroplasty (TKA).

METHODS

Retrospective analysis of a single design RHK TKA (GenuX MK, Implantcast) implanted between 2015 and 2019 including 133 patients (21 primary TKA, 112 revisions). The main indication for revision TKA was second-stage reimplantation following infection. The median follow-up amounted to 30 months (IQR 22-47).

RESULTS

In total, 13% (18/133) of patients underwent revision surgery after a mean time of 1 month (IQR 0-6). The main reason for the revision was (re-) infection in 8% of patients. All revisions were performed following revision TKA and none following primary TKA. There were no revision surgeries for loosening or instability. The revision-free implant survival of 83% was (95% CI 75-91%) after five years. A higher number of previous surgeries was associated with a greater revision risk (p = 0.05).

CONCLUSION

Revision and complex primary TKA using a single-design RHK implant results in good implant survival at mid-term follow-up although infection remains a major concern.

Assessment of the impact of pharmacist-led intervention with antibiotics in patients with bone and joint infection

OBJECTIVES

The management of patients with bone and joint infections (BJIs) is complex. To improve this care, we carried out pharmaceutical actions in the orthopedic unit, including pharmacist-led-intervention (PLI) for patients requiring prolonged antibiotics. Few data exist regarding patient compliance, adherence and knowledge in cases of BJI. Data on hospital readmission are likewise limited, even though it is considered as a major determinant of clinical impact. The aim of this study was to assess the effectiveness of PLI regarding six-month readmissions.

PATIENTS AND METHODS

Patients were assigned to two groups, both receiving standardized care. Two periods were compared: control group (CG) without PLI and interventional group (IG) with PLI throughout. The analysis was based on patient records and included: proportion of rehospitalizations at 6 months for infectious causes, reasons for antibiotic dose modification or antibiotic switch after 6 weeks, and descriptive analysis of data on pharmaceutical interventions in care pathways.

RESULTS

Analysis was performed on 164 patients: 105 CG (64 %) patients and 59 IG (36 %) patients. There were no significant differences between IG and CG in patients' socio-demographic characteristics, infectious factors and antibiotic regimens. Amongst the CG patients, 23 were readmitted (22 %) versus 3 patients in the IG (5 %), (p = 0.002). There were significantly fewer treatment changes after 6 weeks (28.6 % versus 15.3 %, p = 0.05) for IG patients.

CONCLUSION

In this retrospective survey, our results suggest a positive impact of PLI on 6-month readmission for all causes in BJI patients. These results need to be confirmed in a multicentric study.

Orthopaedic infections: what have we learned?

Orthopaedic infections remain challenging complications to treat, with profound economic impact in addition to patient morbidity. The overall estimates of infection after orthopaedic surgery with internal devices has been estimated at 5%, with hospital costs eight times that of those without fracture-related infections and with significantly poorer functional and pain interference PROMIS scores. Orthopaedic infection interventions have been focused on prevention and treatment options. The creation of new modalities for orthopaedic infection treatment can benefit from the understanding of the temporal relationship between bacterial colonization and host-cell integration, a concept referred to as "the race for the surface." Regarding prevention, host modulation and antibiotic powder use have been explored as viable options to lower infection rates. Orthopaedic infection treatment has additionally continued to evolve, with PO antibiotics demonstrating equivalent efficacy to IV antibiotics for the treatment of orthopaedic infections in recent studies. In conclusion, orthopaedic infections remain difficult clinical dilemmas, although evolving prevention and treatment modalities continue to emerge.

Repeat two-stage exchange arthroplasty for recurrent periprosthetic hip or knee infection: what are the chances for success?

INTRODUCTION

Two-stage revision is a frequently chosen approach to treat chronic periprosthetic joint infection (PJI). However, management of recurrent infection after a two-stage exchange remains debated and the outcome of a repeat two-stage procedure is unclear. This study investigates the success rates of repeat two-stage exchange arthroplasty and analyzes possible risk factors for failure.

MATERIALS AND METHODS

We retrospectively identified 55 patients (23 hips, 32 knees) who were treated with repeat resection arthroplasty and planned delayed reimplantation for recurrent periprosthetic joint infection between 2010 and 2019 after a prior two-stage revision at the same institution. The minimum follow-up was 12 months with a median follow-up time of 34 months (IQR 22-51). The infection-free survival, associated revision surgeries, and potential risk factors for further revision were analyzed using Kaplan-Meier survival curves and comparative non-parametric testing.

RESULTS

78% (43/55) underwent reimplantation after a repeat implant removal. Of those who completed the second-stage surgery, 37% (16/43) underwent additional revision for infection and 14% (6/55) underwent amputation. The reinfection-free implant survivorship amounted to 77% (95% CI 64-89%) after 1 year and 38% (95% CI 18-57%) after 5 years. Patients with a higher comorbidity score were less likely to undergo second-stage reimplantation (median 5 vs. 3, p = 0.034). Furthermore, obese patients (p = 0.026, Fisher's exact test) and diabetics (p < 0.001, log-rank test) had a higher risk for further infection. Most commonly cultures yielded polymicrobial growth at the repeat two-stage exchange (27%, 15/55) and at re-reinfection (32%, 9/28). Pathogen persistence was observed in 21% (6/28) of re-reinfected patients.

CONCLUSION

The success rates after repeat two-stage exchange arthroplasty are low. Patients must be counseled accordingly and different modes of treatment should be considered.

Comparison of Static and Articulating Spacers After Periprosthetic Joint Infection

INTRODUCTION

There is no consensus on whether articulating or static spacers are superior during two-stage exchange arthroplasty for periprosthetic joint infection. We aimed to compare surgical time, need for extensile exposure, surgical costs, and treatment success for articulating and static spacers.

METHODS

This was a retrospective review of 229 periprosthetic joint infections treated with two-stage exchange with a minimum of one-year follow-up. For articulating and static spacers, we compared the need for extensile exposure during reimplantation and treatment failure based on an updated definition. Surgical time and costs at both stages were also compared. Subgroup analysis was performed for total knee and hip arthroplasties.

RESULTS

There was no difference in the surgical time for spacer insertion; however, articulating spacers demonstrated reduced surgical time during reimplantation (181 vs. 234 minutes, P < 0.001). In multivariate analysis, there was no difference in extensile exposures (odds ratio 2.20, P = 0.081), but treatment failure was more likely for static spacers (odds ratio 2.17, P = 0.009). Overall surgical costs for two-stage exchange were similar between groups (23,782 vs. 23,766, P = 0.495).

CONCLUSION

Articulating spacers demonstrated shorter surgical times and a trend toward decreased extensile exposures during reimplantation. They also had higher treatment success rates and similar surgical costs for overall two-stage exchange.

A desirability of outcome ranking (DOOR) for periprosthetic joint infection - a Delphi analysis

Background: Treatment outcomes in studies on prosthetic joint infection are generally assessed using a dichotomous outcome relating to treatment success or failure. These outcome measures neither include patient-centred outcome measures including joint function and quality of life, nor do they account for adverse effects of treatment. A desirability of outcome ranking (DOOR) measure can include these factors and has previously been proposed and validated for other serious infections. We aimed to develop a novel DOOR for prosthetic joint infections (PJIs). Methods: The Delphi method was used to develop a DOOR for PJI research. An international working group of 18 clinicians (orthopaedic surgeons and infectious disease specialists) completed the Delphi process. The final DOOR comprised the dimensions established to be most important by consensus with > 75  % of participant agreement. Results: The consensus DOOR comprised four main dimensions. The primary dimension was patient-reported joint function. The secondary dimensions were infection cure and mortality. The final dimension of quality of life was selected as a tie-breaker. Discussion: A desirability of outcome ranking for periprosthetic joint infection has been proposed. It focuses on patient-centric outcome measures of joint function, cure and quality of life. This DOOR provides a multidimensional assessment to comprehensively rank outcomes when comparing treatments for prosthetic joint infection.

Post-operative prophylactic antibiotics in aseptic revision hip and knee arthroplasty: a propensity score matching analysis

The use of extended antibiotic (EA) prophylaxis (> 24 h) remains controversial in aseptic revision arthroplasty. We sought to determine whether EA prophylaxis reduces the risk of periprosthetic joint infection (PJI) in aseptic revision hip and knee arthroplasty. A total of 2800 patients undergoing aseptic revision hip and knee arthroplasty at five institutional databases from 2008 to 2017 were evaluated. One to two nearest-neighbor propensity score matching analysis was conducted between patients who did and did not receive extended antibiotic prophylaxis. The matching elements included age, sex, body mass index, Charlson comorbidity index, hospital distribution, year of surgery, joint (hip or knee), surgical time, CRP, preoperative hemoglobin, albumin, and length of stay. The primary outcome was the development of PJI, which was assessed at 30 days, 90 days, and 1 year following revision and analyzed separately. A total of 2467 (88%) patients received EA prophylaxis, and 333 (12%) patients received standard antibiotic (SA) prophylaxis (≤ 24 h). In the propensity-matched analysis, there was no difference between patients who received EA prophylaxis and those who did not in terms of 30-day PJI (0.3% vs. 0.3%, p = 1.00), 90-day PJI (1.7% vs. 2.1%, p = 0.62) and 1- year PJI (3.8% vs. 6.0%, p = 0.109). For revision hip, the incidence of PJI was 0.2% vs 0% at 30 days (p = 0.482), 1.6% vs 1.4% at 90 days (p = 0.837), and 3.4% vs 5.1% at 1 year (p = 0.305) in the EA and SA group. For revision knee, the incidence of PJI was 0.4% vs 0.9% at 30 days (p = 0.63), 1.8% vs 3.4% at 90 days (p = 0.331), and 4.4% vs 7.8% at 1 year (p = 0.203) in the EA and SA group. A post hoc power analysis revealed an adequate sample size with a beta value of 83%. In addition, the risks of Clostridium difficile and resistant organism infection were not increased. This multi-institutional study demonstrated no difference in the rate of PJIs between patients who received extended antibiotic prophylaxis and those who did not in aseptic revision arthroplasty. The risk of C. difficile and resistant organism infection was not increased with prolonged antibiotic use.

Ceramic-on-polyethylene hip arthroplasty reduces the risk of postoperative periprosthetic joint infection

Metal-on-polyethylene (MoP) total hip arthroplasty (THA) prostheses are known to release metal debris. Basic science studies suggest that metal implants induce a pro-inflammatory response that ultimately chemoattracts leukocytes including macrophages and neutrophils to the surgical site. This raises concern of higher risk of infection with these prostheses through the "trojan horse" mechanism by which neutrophils and macrophages transport intracellular pathogens from a remote site. This study compared the infection occurrence between MoP and ceramic-on-polyethylene (CoP) implants to determine if a higher infection rate in MoP is present. We reviewed a consecutive series of 6052 CoP and 4550 MoP primary THA patients from 2015 to 2019. The occurrence of periprosthetic joint infection at 2 years was defined according to the 2018 ICM definition. Statistical analysis consisted of descriptive statistics, univariate analysis, and regression modeling. When compared to CoP, MoP patients were older, included more females, had a higher body mass index, and more commonly affected by comorbidities according to Elixhauser's score. Total revisions were higher in the MoP group (3.19% vs. 2.41%) The absolute incidence of PJI was higher in MoP (2.40% vs. 1.64%). When we adjusted for confounding factors, MoP was found independently associated with a higher PJI risk. Despite MoP and CoP both being widely used for primary THA, we found a higher incidence of PJI in MoP patients. The association remained significant when controlled for possible confounders. We hypothesize that leukocyte recruitment to these implants may play a role and should be further investigated.

Treatment outcomes of patients with Cutibacterium acnes-positive cultures during total joint replacement revision surgery: a minimum 2-year follow-up

INTRODUCTION

Periprosthetic joint infection (PJI) is a devastating complication following total joint replacement (TJR). Cutibacterium acnes (C. acnes) is a low virulent skin commensal, commonly found during TJR revision surgery for "aseptic" causes. The purpose of the present study was to report the treatment outcomes of patients with C. acnes contamination or infection in the presence of a TJR treated with a revision surgery ± implant exchange ± prolonged (≥ 8 weeks) postoperative antibiotics.

METHODS

Medical records of patients with at least one positive C. acnes culture in intraoperative tissue samples or sonication fluid from a TJR revision surgery between January 2005 and December 2014 were retrospectively evaluated. The primary endpoint was infection eradication according to Delphi criteria. The diagnostic accuracy of preoperative TJR aspiration regarding the diagnosis of C. acnes PJI was also investigated.

RESULTS

A total of 52 TJR (28 shoulders, 17 hips, 7 knees) in 52 patients (35 males, 17 females) with an average age of 63 ± 11 (33-86) years were included. At an average follow-up of 67 ± 33 (24-127) months, the infection eradication of C. acnes PJI was 97% regardless of the surgical treatment or administration of prolonged postoperative antibiotics. The incidence of unsuspected C. acnes PJI was 28.8%. The sensitivity and specificity of preoperative joint aspiration in detecting C. acnes PJI were 59% and 88%, whereas the PPV and NNV were 83% and 67%, respectively.

CONCLUSION

Infection eradication of C. acnes PJI was very high at a minimum follow-up of 24 months, suggesting that C. acnes PJI could be adequately treated with a combination of revision surgery and prolonged postoperative antibiotics. The preoperative diagnosis of C. acnes PJI might be challenging with more than one-quarter of patients presenting without suspicion of C. acnes PJI. The appropriate treatment of patients with a single positive culture remains still unclear. A negative TJR aspiration should not rule out a C. acnes PJI, especially in the presence of clinical correlates of infection.

LEVEL OF EVIDENCE

Retrospective case-control study, Level III.

IRB APPROVAL

Kantonale Ethikkommission Zürich, BASEC Nr.:2017-00567.

The presence of a draining sinus is associated with failure of re-implantation during two-stage exchange arthroplasty

Background: Reinfection rates after two-stage exchange arthroplasty for prosthetic joint infection (PJI) have been reported as high as 33 % in the literature. Understanding risk factors for treatment failure will help to preoperatively counsel patients on the likelihood of successful treatment and possibly influence the surgeon's treatment algorithm. This study aimed to delineate whether the presence of a draining sinus tract is associated with risk of failure of two-stage exchange arthroplasty. Methods: We performed a single institution, multi-center retrospective chart review of outcomes of patients treated for PJI with two-stage exchange arthroplasty between June 2006 and May 2016. For patients treated prior to 2011, PJI was defined based on the preoperative work-up and intraoperative findings as determined by the attending surgeon. After 2011, PJI was defined using MSIS consensus criteria. All patients had a minimum of follow-up of 2 years or treatment failure prior to 2 years. Treatment failure was defined as reinfection or failure to complete two-stage exchange secondary to persistent infection or other host factors. Operative reports and clinical notes were reviewed to assess for presence of a draining sinus tract. Results: 240 patients were treated for PJI with intended two-stage exchange arthroplasty. The overall rate of treatment failure was 29.6 % (71/240), while the overall rate of reinfection was 13.3 % (32/240). A total of 39 patients did not complete second stage revision; final treatment for these patients was amputation, fusion, or chronic antibiotic suppression. A total of 52 of 240 patients (21.7 %) had a draining sinus tract at presentation. Patients with a sinus tract were significantly less likely to be replanted compared to those without a sinus tract at presentation (13.3 % vs. 26.9 %, p=0.02). However, when accounting for all mechanisms of treatment failure, including reinfection following replantation, there was no statistically significant difference detected between the sinus and no-sinus groups (27.7 % vs. 36.5 %, p=0.22). Discussion: A draining sinus tract represents a chronic, deep infectious process with ultimate compromise of overlying soft tissues. Thus we hypothesized it would be associated with failure in a two-stage exchange arthroplasty. These data demonstrate that patients with a draining sinus are significantly less likely to undergo re-implantation. This provides evidence to the paucity of data surrounding draining sinuses and two-stage PJI treatment.

Avoidance of intramedullary violation in computer-assisted total knee arthroplasty lowers the incidence of periprosthetic joint infection compared with conventional total knee arthroplasty: A propensity score matching analysis of 5342 cases

BACKGROUND

Conventional total knee arthroplasty (CONV-TKA) inevitably perturbs femoral medullary canal, disturbs medullary micro-architecture and increases blood loss and inflammatory responses. We hypothesized that avoidance of intramedullary violation may lower the incidence of periprosthetic joint infection (PJI). The aim of this study was to verify whether computer-assisted total knee arthroplasty (CAS-TKA) lowers the incidence of PJI as compared with CONV-TKA.

METHODS

A propensity score matching study of 5342 patients who underwent CAS-TKA (n = 1085) or CONV-TKA (n = 4257) for primary osteoarthritis of the knee from 2007 to 2015 in our institute was performed. Patients who underwent CAS-TKA were matched to those who received CONV-TKA at a 1:2 ratio according to demographics and comorbidities. PJI was defined according to the Musculoskeletal Infection Society diagnostic criteria from the 2013 International Consensus Meeting.

RESULTS

After controlling potential risk factors, the use of CAS-TKA resulted in a lower incidence of PJI as compared with CONV-TKA [adjusted hazard ratio (HR), 0.42; 95% confidence interval (CI), 0.18-0.99]. The same trend in PJI reduction was observed with the usage of CAS-TKA under sensitivity testing [HR, 0.33; 95% CI, 0.12-0.95]. The cumulative incidence of PJI was lower in the CAS-TKA group than the CONV-TKA group (log-rank test, p = 0.013).

CONCLUSION

Avoidance of intramedullary violation during TKA may play a pivotal role in lowering the incidence of PJI. The use of CAS-TKA can reduce the incidence of PJI, with a better survival rate in terms of being free of PJI, as compared with CONV-TKA.

Cement-in-cement revision of the femur in infected hip arthroplasty in 89 patients across two centres

AIMS

Femoral cement-in-cement revision is a well described technique to reduce morbidity and complications in hip revision surgery. Traditional techniques for septic revision of hip arthroplasty necessitate removal of all bone cement from the femur. In our two centres, we have been using a cement-in-cement technique, leaving the distal femoral bone cement in selected patients for septic hip revision surgery, both for single and the first of two-stage revision procedures. A prerequisite for adoption of this technique is that the surgeon considers the cement mantle to be intimately fixed to bone without an intervening membrane between cement and host bone. We aim to report our experience for this technique.

METHODS

We have analyzed patients undergoing this cement-in-cement technique for femoral revision in infection, and present a consecutive series of 89 patients. Follow-up was undertaken at a mean of 56.5 months (24.0 to 134.7) for the surviving cases.

RESULTS

Seven patients (7.9%) required further revision for infection. Ten patients died of causes unrelated to their infection before their two-year review (mean 5.9 months; 0.9 to 18.6). One patient was lost to follow-up at five months after surgery, and two patients died of causes unrelated to their hip shortly after their two-year review was due without attending. Of the remaining patients, 69 remained infection-free at final review. Radiological review confirms the mechanical success of the procedure as previously described in aseptic revision, and postoperative Oxford Hip Scores suggest satisfactory functional outcomes.

CONCLUSION

In conclusion, we found that retaining a well-fixed femoral cement mantle in the presence of infection and undertaking a cement-in-cement revision was successful in 82 of the patients (92.1%) in our series of 89, both in terms of eradication of infection and component fixation. These results are comparable to other more invasive techniques and offer significant potential benefits to the patient. Cite this article: Bone Joint J 2022;104-B(2):212-220.

Increased Prevalence of Depressive Symptoms in Patients Undergoing Revision for Periprosthetic Joint Infection

Background

Periprosthetic joint infection (PJI) is a devastating complication after total joint arthroplasty. Patients undergoing revision for PJI may experience psychological distress and symptoms of depression, both of which are linked to poor postoperative outcomes. We, therefore, aim to identify the prevalence of depression and depressive symptoms in patients before treatment for PJI and their link to functional outcomes.

Methods

Patients undergoing either debridement with implant retention (DAIR) or 2-stage exchange for PJI with minimum 1-year follow-up were retrospectively reviewed. The 2-stage (n = 37) and single-stage (n = 39) patients that met inclusion criteria were matched based off age (±5 years), gender, and body mass index (±5) to patients undergoing aseptic revisions. Outcomes evaluated included a preoperative diagnosis of clinical depression and preoperative and postoperative Veterans RAND 12 Item Health Survey mental component score and physical component score.

Results

Compared to matched controls, the prevalence of depressive symptoms was significantly greater in patients undergoing 2-stage exchange preoperatively (40.5% vs 10.8%, P < .01) but not postoperatively (21.6% vs 10.8%, P = .20). Patients undergoing DAIR with either preoperative depressive symptoms (31.3 vs 40.9, P = .05) or a preoperative diagnosis of depression (27.7 vs 43.1, P < .01) had significantly lower physical component scores postoperatively.

Conclusions

Patients undergoing 2-stage exchange for PJI have a four times higher prevalence of preoperative depressive symptoms than patients undergoing aseptic revision. Patients undergoing DAIR with depression or preoperative depressive symptoms have lower functional scores postoperatively. Orthopedic surgeon screening of PJI patients with referral for treatment of depression may help improve outcomes postoperatively.

Experiences during Switching from Two-Stage to One-Stage Revision Arthroplasty for Chronic Total Knee Arthroplasty Infection

The objective of this study was to evaluate our preliminary results after changing our surgical strategy from 2-stage revision arthroplasty to 1-stage revision arthroplasty for patients with chronic knee periprosthetic joint infection. We conducted a prospective study of knee arthroplasty patients that had been diagnosed with chronic infection and treated using a 1-stage revision regardless of the traditional criteria applied for indication thereof. We evaluated two main variables: infection control and economic costs. The definitive diagnosis of infection of the revision was determined by using the criteria proposed by the Musculoskeletal Infection Society. The costs were calculated as average costs in USD, as described by Srivastava (2019), for 1-stage or 2-stage revisions. Eighteen patients were included in the study, and infection was controlled in 17 patients. The total economic savings for our hospital from these 18 patients amounted to USD 291,152. This clinical success has led to major changes in how our hospital approaches the treatment of chronically infected knee replacements, in addition to substantial economic advantages for the hospital.

Introducing image-guided synovial aspiration and biopsy in assessing peri-prosthetic joint infection: an early single-centre experience

AIM

Synovial sampling can be used in the diagnosis of peri-prosthetic joint infection (PJI). The purpose of this study was to establish the role of simultaneous image-guided synovial aspiration and biopsy (SAB) during an initial 2-year experience at our institution.

METHODS

Retrospective review of consecutive SABs performed during 2014-2016 at a tertiary referral musculoskeletal centre. Radiological SAB microbiology culture results were compared with intra-operative surgical samples or multidisciplinary team (MDT) meeting outcome at 1-year follow-up if surgery was not undertaken. Sensitivity, specificity and accuracy of synovial aspiration (SA), synovial biopsy (SB) and simultaneous SAB were calculated.

RESULTS

103 patients (46 male, 57 female) totalling 111 procedures were analysed with mean age 65 years (range 31-83). Image-guided synovial procedures were performed on 52 (46.9%) hip and 59 (53.1%) knee joint prostheses. The mean combined sensitivity, specificity and accuracy for the entire cohort was 72.6%, 96.9% and 90%, respectively. When only SB was obtained, diagnostic accuracy (92.5%) was similar to SA alone (94.1%). In total, there were 21 (18.9%) true-positive, 80 (72.1%) true-negative, 2 (1.8%) false-positive and 8 (7.2%) false-negative cases (PPV 91.3% and NPV 90.9%). No post-procedural complications were recorded at 1-year follow-up.

CONCLUSION

Percutaneous image-guided SAB is a valuable technique in assessing suspected PJI, with most samples indicative of infective status and causative organisms when validated against intra-operative results and specialist MDT evaluation. Image-guided SB is a safe and useful additional procedure following failed SA with equivalent levels of diagnostic accuracy.

Platelet Deficiency Represents a Modifiable Risk Factor for Periprosthetic Joint Infection in a Preclinical Mouse Model

BACKGROUND

Well known for their hemostatic function, platelets are increasingly becoming recognized as important immunomodulators. The purpose of the present study was to assess the impact of platelet depletion on antimicrobial host defense in a mouse model of periprosthetic joint infection (PJI).

METHODS

Thrombocytopenia (TCP) was induced in C57BL/6 mice with use of a selective antibody against platelet CD41 (anti-CD41). Whole blood from pre-treated mice was incubated with Staphylococcus aureus to assess antimicrobial efficacy with use of bioluminescent imaging, quantitative histological staining, and colony forming unit (CFU) quantification. In parallel, untreated heterologous platelets were added to TCP blood to assess potential rescue of antimicrobial efficacy. In vivo, TCP and control mice underwent placement of a titanium implant in the femur inoculated with bioluminescent Xen36 S. aureus. Longitudinal bioluminescent imaging was performed postoperatively to quantify the evolution of bacterial burden, which was confirmed via assessment of S. aureus CFUs on the implant and in peri-implant tissue on postoperative day (POD) 28.

RESULTS

Anti-CD41 treatment resulted in significant dose-dependent reductions in platelet count. Ex vivo, platelet-depleted whole blood demonstrated significantly less bacterial reduction than control blood. These outcomes were reversed with the addition of untreated rescue platelets. In vivo, infection burden was significantly higher in TCP mice and was inversely correlated with preoperative platelet count (r2 = 0.63, p = 0.037). Likewise, CFU quantification on POD28 was associated with increased bacterial proliferation and severity of periprosthetic infection in TCP mice compared with controls.

CONCLUSIONS

Thrombocytopenia resulted in an increased bacterial burden both ex vivo and in vivo in a mouse model of PJI.

CLINICAL RELEVANCE

In orthopaedic patients, deficiencies in platelet quantity or function represent an easily modifiable risk factor for PJI.

Potential Use of Adjuvant Bacteriophage Therapy With Debridement, Antibiotics, and Implant Retention Surgery to Treat Chronic Prosthetic Joint Infections

The number of arthroplasties conducted annually continues to increase; however, approximately 1%–2% of all knee and hip arthroplasties will become infected. These prosthetic joint infections are costly, difficult to treat, and cause significant morbidity and mortality as a direct result of conventional surgical and medical managements. In this perspective, we discuss factors that make these infections arduous to treat as well as the potential use of adjuvant bacteriophage therapy with debridement, antibiotics, and implant retention surgery to cure these infections without removing the infected prosthesis. We also provide rationale as to why future clinical trials evaluating this novel therapeutic will need to be designed as noninferiority trials, and we compare this approach to 2-stage revision surgery. If bacteriophage therapy continues to show effectiveness, this could revolutionize the treatment of prosthetic joint infections and pioneer new treatments for similar infections.

The effect of hospital case volume on re-revision following revision total knee arthroplasty

AIMS

The aim of this study was to measure the effect of hospital case volume on the survival of revision total knee arthroplasty (RTKA).

METHODS

This is a retrospective analysis of Scottish Arthroplasty Project data, a nationwide audit which prospectively collects data on all arthroplasty procedures performed in Scotland. The primary outcome was RTKA survival at ten years. The primary explanatory variable was the effect of hospital case volume per year on RTKA survival. Kaplan-Meier survival curves were plotted with 95% confidence intervals (CIs) to determine the lifespan of RTKA. Multivariate Cox proportional hazards were used to estimate relative revision risks over time. Hazard ratios (HRs) were reported with 95% CI, and p-value < 0.05 was considered statistically significant.

RESULTS

From 1998 to 2019, 8,301 patients (8,894 knees) underwent RTKA surgery in Scotland (median age at RTKA 70 years (interquartile range (IQR) 63 to 76); median follow-up 6.2 years (IQR 3.0 to 10.2). In all, 4,764 (53.6%) were female, and 781 (8.8%) were treated for infection. Of these 8,894 knees, 957 (10.8%) underwent a second revision procedure. Male sex, younger age at index revision, and positive infection status were associated with need for re-revision. The ten-year survival estimate for RTKA was 87.3% (95% CI 86.5 to 88.1). Adjusting for sex, age, surgeon volume, and indication for revision, high hospital case volume was significantly associated with lower risk of re-revision (HR 0.78 (95% CI 0.64 to 0.94, p < 0.001)). The risk of re-revision steadily declined in centres performing > 20 cases per year; risk reduction was 16% with > 20 cases; 22% with > 30 cases; and 28% with > 40 cases. The lowest level of risk was associated with the highest volume centres.

CONCLUSION

The majority of RTKA in Scotland survive up to ten years. Increasing yearly hospital case volume above 20 cases is independently associated with a significant risk reduction of re-revision. Development of high-volume tertiary centres may lead to an improvement in the overall survival of RTKA. Cite this article: Bone Joint J 2021;103-B(4):602-609.

Clinical Outcome of Two-Stage Revision after Periprosthetic Shoulder Infection

Background: Periprosthetic shoulder infections are devastating complications after shoulder arthroplasty. A potential treatment concept is a two-stage prosthesis exchange. Data are sparse in terms of clinical outcome, including infection-free survival and patient satisfaction after this procedure. In the present study, we investigated recurrence of infection, revision-free survivorship and clinical outcome following two-stage revision due to periprosthetic shoulder infection. Furthermore, reasons for poor outcome were analyzed. Methods: Sixteen patients undergoing two-stage revision after shoulder joint infection were retrospectively identified. Recurrence of infection was analyzed by Kaplan–Meier survival curve. Clinical outcome was quantified with subjective shoulder value (SSV), “quick” Disabilities of the Arm, Shoulder and Hand (qDASH) and Rowe score. Range of motion (ROM) was measured pre- and postoperatively. Postoperative scores and ROM were compared in a subgroup analysis according to different reimplanted prosthesis types. Results: The reinfection-free implant survival was 81% after one year and at final follow-up (FU; mean of 33.2 months). The overall revision-free survival amounted to 56% after one year and at final FU. Patients who received reverse shoulder arthroplasty (RSA) as part of reimplantation had less disability and long-term complications. This group demonstrated better subjective stability and function compared to patients revised to megaprostheses or large-head hemiarthroplasties. Conclusions: Two-stage revision following periprosthetic joint infection of the shoulder allows appropriate infection control in the majority of patients. However, the overall complications and revision rates due to mechanical failure or reinfection are high. Reimplantation of RSA seem superior to alternative prosthesis models in terms of function and patient satisfaction. Therefore, bone-saving surgery and reconstruction of the glenoid may increase the likelihood of reimplantation of RSA and potentially improve outcome in the case of infection-related two-stage revision of the shoulder.