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

BACKGROUND: There is still no consensus among surgeons on whether to perform a 1- or 2-stage surgical revision in infected shoulder arthroplasties. The aim of this systematic review and meta-analysis is to rigorously synthesize published studies evaluating the clinical outcomes, recurrence of infection, and other clinical complications in order to discuss which is the best strategy for treating periprosthetic joint infection after shoulder arthroplasty. METHODS: Upon research using the PubMed, Scopus, and Web of Science databases, in November 2022, studies that presented 1- or 2-stage surgical revision as a treatment for periprosthetic joint infection after shoulder arthroplasty and assessed the reinfection rate on these patients, as well as other clinical outcomes, with a minimum follow-up of 12 months, were included. Study quality was evaluated using the Methodological Index for Non-Randomized Studies (MINORS) score. Reinfection and complication rates were extracted, and pooled estimates were calculated using the random-effect model. RESULTS: After careful screening, 44 studies were included, 5 reporting on 1-stage and 30 on 2-stage revisions and 9 assessing both strategies. A total of 185 shoulders were reported in 1-stage revision studies, whereas 526 shoulders were reported in 2-stage revision studies. The overall pooled random-effects reinfection rate was 6.68% (95% confidence interval [CI]: 3.76-10.13), with low heterogeneity (I2 = 28%, P = .03). One-stage revision showed a reinfection rate of 1.14% (95% CI: 0.00-4.88), whereas 2-stage revision analysis revealed a reinfection rate of 8.81% (95% CI: 4.96-13.33). There were significant statistical differences between 1- and 2-stage reinfection rates (P = .04). The overall pooled rate for other clinical complications was 16.76% (95% CI: 9.49-25.15), with high heterogeneity (I2 = 70%, P < .01). One-stage revision had a complication rate of 6.11% (95% CI: 1.58-12.39), whereas the 2-stage revision complication rate was 21.26% (95% CI: 11.51-32.54). This difference was statistically significant (P = .03). CONCLUSIONS: This is the first systematic review and meta-analysis showing significant statistical differences between 1- and 2-stage surgical revision in infected shoulder arthroplasties. Provided the right conditions exist, 1-stage revision shows better results in infection control, with lower clinical complications and possible better clinical outcomes.

Direct Hospital Costs per Case of Periprosthetic Hip and Knee Joint Infections in Europe - A Systematic Review.

BACKGROUND: The rise of periprosthetic joint infections (PJIs) due to aging populations is steadily increasing the number of arthroplasties and treatment costs. This study analyzed the direct health care costs of PJI for total hip arthroplasty and total knee arthroplasty (TKA) in Europe. METHODS: The databases PubMed, Scopus, Embase, Cochrane, and Google Scholar were systematically screened for direct costs of PJI in Europe. Publications that defined the joint site and the procedure performed were further analyzed. Mean direct health care costs were calculated for debridement, antibiotics, and implant retention (DAIR), one-stage, and 2-stage revisions for hip and knee PJI, respectively. Costs were adjusted for inflation rates and reported in US-Dollar (USD). RESULTS: Of 1,374 eligible publications, 12 manuscripts were included in the final analysis after an abstract and full-text review. Mean direct costs of $32,933 were identified for all types of revision procedures for knee PJI. The mean direct treatment cost including DAIR for TKA after PJI was $19,476. For 2-stage revisions of TKA, the mean total cost was $37,980. For all types of hip PJI procedures, mean direct hospital costs were $28,904. For hip DAIR, one-stage and 2-stage treatment average costs of $7,120, $44,594, and $42,166 were identified, respectively. CONCLUSIONS: Periprosthetic joint infections are associated with substantial direct health care costs. As detailed reports on the cost of PJI are scarce and of limited quality, more detailed financial data on the cost of PJI treatment are urgently required.

Proceedings of the United Kingdom Periprosthetic Joint Infection Meeting 2022: Combined and Arthroplasty Sessions.

Considerable variation in practice exists in the prevention, diagnosis, and treatment of periprosthetic joint infection (PJI), which is a devastating complication for patients and surgeons. The consensus principle has been increasingly embraced by the orthopaedic community to help guide practice, especially where high-level evidence remains unavailable. The third United Kingdom Periprosthetic Joint Infection (UK PJI) Meeting was held in Glasgow on April 1, 2022, with more than 180 delegates in attendance, representing orthopaedics, microbiology, infectious diseases, plastic surgery, anesthetics, and allied health professions, including pharmacy and arthroplasty nurses. The meeting comprised a combined session for all delegates, and separate breakout sessions for arthroplasty and fracture-related infection. Consensus questions for each session were prepared in advance by the UK PJI working group, based upon topics that were proposed at previous UK PJI Meetings, and delegates participated in an anonymized electronic voting process. We present the findings of the combined and arthroplasty sessions of the meeting in this article, and each consensus topic is discussed in relation to the contemporary literature.

Evaluation of interleukin-6 in synovial fluid in periprosthetic joint infection of the elbow.

PURPOSE: Searching for quick determinable biomarkers with high sensitivity and specificity is necessary to improve and optimise the early diagnosis of periprosthetic elbow infection (PEI). Therefore, this study's objective was to evaluate the diagnostic value of synovial fluid interleukin-6 (IL-6) levels for diagnosing PEI in total elbow arthroplasty. METHOD: Twelve prospective enrolled patients underwent total elbow arthroplasty revision surgery, during which synovial fluid was obtained. Between the initial implantation and the revision procedure were 33.5 ± 41 months (range, 2-144 months). Synovial fluid was collected for immediate IL-6 analysis parallel to the revision surgery. Furthermore, microbiological samples were obtained and analysed. Two groups were defined based on the microbiological results: non-infection and infection group. The ability of synovial fluid IL-6 analysis to predict infection status was explored using receiver operating characteristic curves and further statistical analysis. RESULTS: Synovial fluid IL-6 analysis had a good diagnostic accuracy of 83% for PEI with an area under the curve of 0,79 and an ideal cutoff value (determined using Youden's criterion) of 15244 pg/mL. DISCUSSION: This is the first study to clinically evaluate IL-6 as a diagnostical marker for periprosthetic joint infection (PJI) in total elbow arthroplasty. Our results suggest a good accuracy and high sensitivity for IL-6 to identify a PEI. The analysis of IL-6 can improve surgical decision-making regarding managing total elbow arthroplasty in terms of one- or two-staged revision. CONCLUSION: IL-6 can play an important role in the perioperative differentiation of infected and non-infected situations.

Are silver-coated megaprostheses superior to uncoated megaprostheses in managing chronic end-stage periprosthetic hip and knee infection?

INTRODUCTION: Outcomes for silver coated megaprostheses (SC-MP) used in cases of end-stage periprosthetic joint infection (PJI) have not been clearly defined. Although attractive, concerns over implant longevity and the risk of infection relapse exist among the scientific community. Therefore, we sought to investigate the effect of silver coating in lower-extremity MPs used in such difficult-to-treat scenarios. The study's primary hypothesis was that the periprosthetic infection control rate would be higher in patients with silver-coated implants. MATERIALS AND METHODS: Non-interventional retrospective study with a historical comparison group. We identified all consecutive end-stage hip and knee PJI cases at our center managed with exchange arthroplasty using a silver-coated megaprosthesis from January 2016 to March 2021, these cases were compared with a historical cohort of end-stage PJI cases managed with uncoated megaprostheses. The main outcome studied was infection control rate. Secondarily, we analyzed the short-to-medium-term survivorship of this type of silver-coated implant. RESULTS: Fifty-nine megaprostheses used in cases of end-stage PJI were included in this study. We identified 30 cases of chronic hip or knee PJI in which a silver-coated modular megaprosthesis was implanted. Our non-coated megaprosthesis (NC-MP) historical group included 29 patients. Both groups had similar demographic characteristics. We found no statistically significant differences in infection control rate (80% vs. 82.8%, p = 0.47) or implant survivorship (90% vs. 89.65%, p = 1) after a mean follow-up for SC-MP of 46.43 months, and 48 months for the non-coated MP group. In relapsed cases, there were no differences in infection eradication after DAIR (66% SC-MP vs. 60% NC-MP success rate, p = 1). During the follow-up we observed one case of skin argyria without further repercussion. CONCLUSION: We were unable to confirm our initial hypothesis that use of silver-coated implants in end-stage PJI scenarios may be associated with better outcomes in terms of infection control or implant survivorship.

Adjuvant intra-articular vancomycin for recalcitrant Staphylococcal prosthetic joint infections of the knee.

OBJECTIVE: Chronic prosthetic joint infection patients who fail conventional two-stage revision surgery are an especially difficult to treat patient population. Consequently, the objective of this study was to investigate the safety and long-term effectiveness of adjuvant intra-articular vancomycin therapy in conjunction with two-stage revision knee arthroplasties for recalcitrant Staphylococcal prosthetic joint infections. METHODS: This was an observational cohort study of twelve patients with recalcitrant Staphylococcal prosthetic joint infections of the knee which had failed previous revision surgeries. Each patient subsequently underwent two-stage revision with placement of Hickman catheters to deliver intra-articular vancomycin therapy. In addition, systemic antibiotic therapy was administered for 6 weeks, and long-term follow-up was evaluated then for 5 years. RESULTS: Seventy-five percent of the cohort have had no recurrence of their infections at 5 years. Two patients formed fistulas requiring above the knee amputations, and three patients had acute kidney injury. All patients had maximum measurable serum vancomycin trough levels that ranged from 6.1 to 93.6 mcg/mL. CONCLUSION: The aggressive protocol used in this cohort with repeat two-stage revision surgery, intra-articular vancomycin and systemic antibiotics was able to prevent recurrence of infection in most patients, but higher than expected rates of acute kidney injury were observed in this study. Therefore, while intra-articular vancomycin therapy may have some effectiveness in treating recalcitrant prosthetic joint infections, its ability to eradicate all bacterial niduses is unproven, and clinicians should be cognizant of potential adverse events that can occur with this therapy.

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.

Long-term risk of reoperation after modular hemiarthroplasty : Any differences between uni- or bipolar design?

BACKGROUND: It is unclear whether unipolar (UHA) or bipolar (BHA) hemiarthroplasty should be the preferred treatment of femoral neck fracture (FNF). AIM: We investigated the reoperation rate at 13 years post-fracture after BHA and UHA as treatment of FNF, including a subgroup analysis of individuals who survived 5 years or more, and described the reasons for reoperation after BHA and UHA respectively. METHODS: In an observational cohort study on prospectively collected national register data, 16,216 BHA and 22,186 UHA were available for matching. A propensity score for treatment with bipolar HA was estimated using logistic regression. Matching was done using the 1:1 nearest neighbor matching without replacement. Of the 16,216 BHA patients, 12,280 were matched to a UHA control. A subgroup analysis based on the matched sample excluded individuals who died within 5 years and comprised 3,637 individuals with BHA and 3,537 with UHA. Kaplan-Meier survival analysis was used. RESULTS: In the Kaplan-Meier analysis, 92% of the BHA group was free from reoperation at 13 years (95% CI 0.91-0.93), compared to 92% in the UHA group (CI 0.89-0.94). BHA was associated with more reoperations until 3 years. Reoperation due to infection was most common after BHA, n = 212 (1.7%) compared to n = 141 (1.1%) after UHA. Dislocation led to reoperation in 192 of the BHA cases (1.6%) and in 157 of the UHA cases (1.3%). Acetabular erosion/pain occurred in 0.1% and 0.4%. Amongst those surviving ≥ 5 years, 93% of the BHA group was free from reoperation (CI 0.92-0.94) at 13 years, 92% after UHA (CI 0.90-0.94). BHA had more reoperations during the 1st year only. The causes for reoperations showed similar rates except for acetabular erosion/pain. Here the BHA group had 2 cases (0.1%), the UHA had 39 (1.1%). CONCLUSION: With a modular hemiarthroplasty relatively few patients need a reoperation. During the first years, there is a higher reoperation rate after BHA compared to UHA. Thereafter, no differences are seen. In patients who survive ≥ 5 years after the fracture there are more reoperations due to acetabular erosion after UHA, but crude numbers are extremely low, and the total reoperation rate is not affected.

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

BACKGROUND: Shoulder arthroplasty is a successful procedure to treat degenerative and traumatic diseases of the glenohumeral joint. Periprosthetic infection represents an infrequent but dreaded complication (2%-4%). Application of intrawound vancomycin powder seems to reduce periprosthetic infections, but limited information is available on its efficiency in shoulder arthroplasty. The purpose of this study was to evaluate if the vancomycin powder embedded in a collagen sponge could decrease the rate of prosthetic shoulder infection. METHODS: A retrospective analysis of 827 patients undergoing total shoulder arthroplasty was performed. The study involved a control group of 405 patients and a group of 422 with the intraoperative insertion of intrawound vancomycin powder. Incidence of periprosthetic infection was evaluated comparing the 2 groups at a minimum follow-up of 12 months. Patient demographics, comorbidities, and perioperative information were compared between the 2 groups. RESULTS: No infection was observed in the group treated with intrawound vancomycin, and 13 cases of infection were observed in the control group (3.2%) (P value <.001) without subacromial vancomycin application. No wound complications requiring revision were observed as a result of intrawound vancomycin application. DISCUSSION AND CONCLUSION: Intrawound vancomycin powder significantly reduces the rate of periprosthetic shoulder infections without any increase in local and systemic aseptic complications at a minimum follow-up of 12 months. Our results support the use of intrawound local vancomycin for prophylaxis of shoulder periprosthetic infections.

Preoperative prophylactic antibiotics administration does not influence culture yield in revision shoulder arthroplasty.

BACKGROUND: The importance of administrating prophylactic antibiotics prior to a surgical procedure is well established. Given the difficulty in diagnosing shoulder periprosthetic infections, which are more indolent in nature, some advocate holding prophylactic antibiotics prior to obtaining cultures as there is a concern antibiotics may lead to a false negative culture result. The purpose of this study is to determine whether administration of antibiotics prior to obtaining cultures in revision shoulder arthroplasty influences culture yield. METHODS: This was a retrospective analysis of revision shoulder arthroplasty cases performed at a single institution between 2015 and 2021. During the study period, each surgeon had a standardized protocol that dictated whether antibiotics were given or held prior to each revision surgery. Each case was categorized into either a Preculture antibiotic group, if antibiotics were administered prior to incision, or a Postculture antibiotic group if antibiotics were administered after incision and obtaining cultures. The International Consensus Meeting (ICM) scoring criteria provided by the Musculoskeletal Infection Society was used to categorize the probability of periprosthetic joint infection for each case. Culture positivity was calculated as the ratio of positive cultures and total number of cultures obtained. RESULTS: One hundred twenty-four patients met inclusion criteria. There were 48 patients in the Preculture group and 76 patients in the Postculture group. No significant difference in patient demographics or ICM criteria (P = .09) was observed between the 2 groups. With regard to culture positivity, there was no difference between the Preculture antibiotic group and the Postculture antibiotic group (16% vs. 15%, P = .82, confidence interval = 8%-25% vs. 10%-20%, respectively). CONCLUSION: In the setting of revision shoulder arthroplasty, timing of antibiotic administration did not significantly influence culture yield. This study supports the use of prophylactic antibiotics prior to obtaining cultures in revision shoulder arthroplasty.

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.

Morbidly Obese Patients Undergoing Unicompartmental Knee Arthroplasty Compared to Total Knee Arthroplasty: A Retrospective Case-Controlled Analysis.

BACKGROUND: In this study, we assess the effects that morbid obesity (body mass index (BMI) ≥ 40) has on: (1) Ninety-day medical complications and readmission rates; (2) costs of care and lengths of stay (LOS); and (3) 2-year implant complications in patients undergoing unicompartmental knee arthroplasty (UKA) versus total knee arthroplasty (TKA). METHODS: A retrospective query of TKA and UKA patients were identified using a national database. Morbidly obese UKA patients were matched 1:5 to morbidly obese TKA patients by demographic and comorbidity profiles. Subgroup analyses were conducted using the same process between morbidly obese UKA patients and BMI <40 TKA patients, as well as to BMI <40 UKA patients. RESULTS: Morbidly obese patients who underwent UKA had significantly fewer medical complications, readmissions, and periprosthetic joint infections than TKA patients; however, UKA patients had greater odds of mechanical loosening (ML). The TKA patients had significantly longer LOS (3.0 versus 2.4 days, P < .001), as well as significantly greater costs of care than UKA patients ($12,869 versus $7,105). Morbidly obese UKA patients had similar rates of medical complications, and significantly lower readmissions, decreased LOS, and decreased costs when compared to TKA patients who had a BMI <40. CONCLUSION: In patients who have morbid obesity, complications were decreased in UKA compared to TKA. Moreover, morbidly obese UKA patients had lower medical utilizations and similar complication rates when compared to TKA patients with the recommended cutoff of BMI <40. However, UKA patients had greater rates of ML than TKA patients. A UKA may be an acceptable treatment option for unicompartmental osteoarthritis in morbidly obese patients.

The Practice Patterns of American Association of Hip and Knee Surgeons for the Management of Chronic Periprosthetic Joint Infection After Total Knee Arthroplasty.

BACKGROUND: The management of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) has considerable variation. In order to better capture current preferences for the management of PJI, this study sought to poll the current members of American Association of Hip and Knee Surgeons (AAHKS) first to characterize the distribution of practice patterns. METHODS: There were 32 questions in an online survey distributed to members of AAHKS. The questions were multiple choice regarding the management of PJI for TKA. There were 844 out of 2,752 members who completed the survey (response rate of 31%). RESULTS: Most of the members were in private practice (50%) compared to 28% being in an academic setting. On average, members were performing between 6 to 20 PJI cases per year. Two-stage exchange arthroplasty was performed in over 75% of the cases with either a cruciate retaining (CR) or posterior stabilized (PS) primary femoral component used in over 50% of the cases and 62% using an all-polyethylene tibial implant. Most of the members were using vancomycin and tobramycin. Typically, 2 to 3 grams of antibiotics were added per bag of cement regardless of the cement type. When indicated, amphotericin was the most often-used antifungal. Post-operative management had major variability with range of motion, brace use, and weight-bearing restrictions. CONCLUSION: There was variability in the responses from the members of AAHKS, but there was a preference toward performing a two-stage exchange arthroplasty with an articulating spacer using a metal femoral component and an all-polyethylene liner.

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

PURPOSE: The objective of the study was to compare the functional outcomes and the complication rate of the patients with C. acnes contamination at the end of the primary reverse shoulder arthroplasty (RSA) surgery to those patients without C. acnes contamination. METHOD: A total of 162 patients were included. In all cases, skin and deep tissue cultures were obtained. A molecular typing characterization of the C. acnes strains was performed. Functional outcomes were assessed with the Constant score at the two and five year follow-up and all complications were also recorded. RESULTS: A total of 1380 cultures were obtained from the 162 primary RSA surgeries. Of those, 96 turned out to be positive for C. acnes. There were 25 patients with positive cultures for C. acnes. The overall postoperative Constant score was not significantly different between those patients having C. acnes-positive cultures and those with negative cultures at the two and five year follow-up (59.2 vs. 59.6 at two years, p 0.870, and 59.5 vs. 62.4 at five years, p 0.360). Patients with positive cultures presented a higher complication rate (p 0.001) with two infections, one revision surgery, and one dislocation. CONCLUSION: Patients ending up with C. acnes-positive cultures after primary shoulder arthroplasty surgery do not have worse clinical outcomes when compared to patients having negative cultures, but a greater number of complications were found in those patients with C. acnes-positive cultures.

Povidone-iodine irrigation reduces infection after total hip and knee arthroplasty.

INTRODUCTION: One of the most important challenges faced by orthopedic surgeons is periprosthetic joint infection (PJI). PJI is a common cause for total joint arthroplasty failure with an incidence of 0.3-1.9%. PJI can be devastating for the patient and extremely costly for the healthcare system. There is concern that a major cause of PJI is intra-operative colonization and recent studies have shown a decrease in PJI with the use of dilute povidone-iodine (Betadine®, Avrio Health L.P, Stamford, CT) irrigation prior to wound closure. This study presents our experience with the use of dilute Betadine® irrigation prior to wound closure and its effect on our post-operative hip and knee arthroplasty acute infection rate. MATERIALS AND METHODS: Retrospective chart review performed at our hospital looking at PJI amongst patients who underwent primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) between 2013 and 2017 comparing different irrigation methods (n = 3232). The study group (n = 1207) underwent irrigation prior to wound closure with dilute Betadine for 3 min and the control group (n = 1511) underwent irrigation using normal saline (NS). RESULTS: Using a logistic regression model where the following variables were adjusted for; ASA, age, sex, foley insertion, surgical duration and diabetes mellitus status a statistical significant reduction was seen in any infection (OR 0.45 [0.22; 0.89], p value < 0.05) and SSI (OR 0.30 [0.13; 0.70], p value 0.01) with the Betadine group. No significant reduction was seen with deep infections with the Betadine group compared to the NS group. CONCLUSION: PJI is a devastating complication following total joint arthroplasty and we found Betadine compared to NS irrigation provides an inexpensive and simple method to lower any PJI and more specifically SSI in THA and TKA. LEVEL OF EVIDENCE: III.

Two-stage revision for periprosthetic joint infection in cemented total hip arthroplasty: an increased risk for failure?

BACKGROUND: The impact of the prior fixation mode on the treatment outcome of chronic periprosthetic joint infection (PJI) of the hip is unclear. Removal of cemented total hip arthroplasty (THA) is particularly challenging and residual cement might be associated with reinfection. This study seeks to compare the results of two-stage revision for PJI in cemented and cementless THA. METHODS: We reviewed 143 consecutive patients undergoing two-stage revision THA for PJI between 2013 and 2018. Thirty-six patients with a fully cemented (n = 6), hybrid femur (n = 26) or hybrid acetabulum (n = 4) THA (cemented group) were matched 1:2 with a cohort of 72 patients who underwent removal of a cementless THA (cementless group). Groups were matched by sex, age, number of prior surgeries and history of infection treatment. Outcomes included microbiological results, interim re-debridement, reinfection, all-cause revision, and modified Harris hip scores (mHHS). Minimum follow-up was 2 years. RESULTS: Compared with PJI in cementless THA, patients undergoing removal of cemented THA had increasingly severe femoral bone loss (p = 0.004). Patients in the cemented group had an increased risk for positive cultures during second-stage reimplantation (22% compared to 8%, p = 0.043), higher rates of reinfection (22% compared to 7%, p = 0.021) and all-cause revision (31% compared to 14%, p = 0.039) compared to patients undergoing two-stage revision of cementless THA. Periprosthetic femoral fractures were more frequent in the group of patients with prior cementation (p = .004). Mean mHHS had been 37.5 in the cemented group and 39.1 in the cementless group, and these scores improved significantly in both groups (p < 0.01). CONCLUSION: This study shows that chronic infection in cemented THA might be associated with increased bone loss, higher rates of reinfection and all-cause revision following two-stage revision. This should be useful to clinicians counselling patients with hip PJI and can guide treatment and estimated outcomes.

Total hip arthroplasty for destructive septic arthritis of the hip using a two-stage protocol without spacer placement.

INTRODUCTION: The optimal treatment of patients with a degenerative joint disease secondary to an active or chronic septic arthritis of the hip is unclear. The aim of the present study was to report on our experience with two-stage total hip arthroplasty (THA) using a contemporary treatment protocol without spacer insertion. MATERIALS AND METHODS: Our prospective institutional database was used to identify all patients with degenerative septic arthritis treated with a non-spacer two-stage protocol between 2011 and 2017. Clinical outcomes included interim revision, periprosthetic infection (PJI) and aseptic revision rates. Restoration of leg-length and offset were assessed radiographically. Modified Harris hip score (mHHS) were obtained. Treatment success was defined using the modified Delphi consensus criteria. Mean follow-up was 62 months (13-110). RESULTS: A total of 33 patients with a mean age of 60 years (13-85) were included. 55% of the cohort was male and average Charlson Comorbidity Index (CCI) was 3.7 (0-12). 21 patients (64%) had an active/acute infection and 12 patients (36%) were treated for chronic/quiescent septic arthritis. Overall, 11 patients (33%) had treatment failure, including 5 patients who failed to undergo THA, 2 interim re-debridement for persistent infection, and 4 patients who developed PJI after an average of 7 months (0.3-13) following THA. The most common identified pathogen was Staphylococcus aureus (42.4%). No aseptic revision was recorded following THA. Leg-length and offset were successfully restored. Mean mHHS improved from 35.2 points to 73.4 points. CONCLUSION: Two-stage THA without spacer placement is a viable treatment option for destructive septic arthritis of the hip, demonstrating comparable rates of infection control and functional outcome. However, definitive resection arthroplasty is not uncommon in these often critically ill patients.

C-reactive protein during the first 6 postoperative days after total hip arthroplasty cannot predict early periprosthetic infection.

INTRODUCTION: Periprosthetic joint infection (PJI) after total hip arthroplasty (THA) remains a serious complication in orthopaedic surgery. C-reactive protein (CRP) is widely used as a marker to screen for inflammatory complications. The early postoperative course is well known, but knowledge about the predictive value of CRP in the first 6 postoperative days for detecting an acute postoperative PJI is lacking. METHODS: We retrospectively analyzed the inpatient course of CRP of all primary THA and THA with acute PJI within 28 days in our hospital from 2013 to 2021. A receiver-operating curve (ROC) analysis was performed and the best CRP threshold for detecting an acute PJI based on Youden's-index was calculated and an area-under-the curve (AUC) analysis of the threshold was performed. RESULTS: 33 of 7042 patients included had an acute PJI within 28 days. Patients with acute PJI were older, had a higher BMI and longer operation time and suffered more often from diabetes mellitus. A preoperatively elevated CRP was a risk factor for PJI. CRP was significantly higher in the PJI group on postoperative days 3 and 5. Threshold values were calculated to be 152 mg/l on day 3 and 73 mg/l on day 5. However, these values had a low sensitivity (75%, 76%) and specificity (67%, 61%). CONCLUSION: Especially considering the decreasing length of stay after THA, the question of the usefulness of regular inpatient CRP checks arises. AUC analysis of the ROC showed a poor diagnostic accuracy in almost all cases. Only the dynamic analysis of the maximum CRP value to the lowest CRP value with a decrease of 102.7 mg/l showed a fair accuracy. This calls into question the clinical relevance of CRP in the first postoperative week for detection of acute postoperative PJI.

What is the failure rate of constrained liners in complex revision total hip arthroplasty?

BACKGROUND: Recurrent hip dislocation after multiple revision total hip arthroplasty is a severe complication. Therefore, constrained acetabular liners (CL) have been used during salvage procedures. We report our experience of constrained liners in a re-revision setting with focus on re-dislocation. We also evaluated acetabular and femoral bone loss as potential risk factor. METHODS: Between January 2013 and December 2016, 65 patients were treated in a single institution for revision and re-revision hip arthroplasty using CL. The indication for using a CL was a high risk of re-redislocation after multiple recurrent hip dislocation including failed Dual Mobility Cups (DMC). Compromising soft tissue defects as well as severe bone defect were therefore regarded as high risks. Thirty-eight patients (77.6%) underwent a minimum of three surgical procedures before the index revision procedure. Sixteen patients (24.6%) were excluded as they were lost to follow-up, expired before minimum follow-up or refused study participation, leaving 49 patients in the analysis (75.4%). The mean follow-up was 62 months (44-74; SD = 7.7). We assessed the following potential risk factors for revision or dislocation: type of surgical setting (septic/aseptic), BMI, cup inclination angle, size of liner used and acetabular and femoral bone loss according to Paprosky classification. The primary endpoints were dislocation or repeat revision for any reason. RESULTS: Of the 49 patients, we found an overall re-revision rate of 40.8% (20/49) and a dislocation rate of 30.6% (15/49). There were no significant differences among the surgical re-revision rate or dislocation rate as a factor of patient characteristics. In terms of bone loss, there was a trend towards higher revision rates for increasing acetabular and femoral bone loss, but without statistical significance. CONCLUSIONS: We found the use of a constrained liner in a re-revision setting still bears a high risk of re-revision and re-dislocation. Therefore we restrained from using constrained liners in favour of Dual mobility cups. In this study there was no significant higher dislocation rate in the subgroup of periprosthetic infection. Furthermore the rigid design of a constrained liner bears the known risk of structural failure of acetabular reconstruction implants. Severe acetabular or femoral bone defects seem to have an impact on the revision rate, but not on the dislocation rate with regards to the restored offset and center of the hip. Results have to be taken into context such that the study population inherently has a predisposition for poorer outcomes. Indications should be strongly filtered for patients at high risk for recurrent hip joint dislocation including failed DMCs with only limited bone loss and moderate soft tissue defects. Our modification to the existing classification with a high inter and intraobserver reliability will make future studies more comparable regarding revisions and bone stock loss. Still further research using objective and reproducible parameters is needed to better analyze data especially in the background of complex revision hip arthroplasty.

[Periprosthetic gout flare after total knee arthroplasty: A misdiagnostic case report].

Periprosthetic gout flare is a rare arthritic condition after total knee arthroplasty, but the symptoms of gout may have often been mistaken as acute periprosthetic infection given their similarity. Misdiagnosis as periprosthetic infection can lead to unnecessary surgery, long-term dependence on anti-biotics, and even malfunction of the involved knee joint. Here, we report a case study of a patient with immunodeficiency condition of long-term oral glucocorticoid and diabetes mellitus, who had undergone a knee replacement 8 weeks before. The initial symptoms of fever and joint pain together with the dysfunction of her right knee with elevated inflammatory markers, such as increased serum leukocytes, erythrocyte sedimentation rate, C-reactive protein, and synovial cell counts led to a diagnosis of acute periprosthetic infection. Arthrocentesis and bacterial culture were performed preoperatively. According to the current Musculoskeletal Infection Society (MSIS) criteria for diagnosis of periprosthetic infection, the case was classified as periprosthetic infection and a prosthesis retained debridement surgery was performed. However we got negative culture results in all the pre-operative and intro-operative samples. The symptoms as well as the laboratory inflammatory markers improved shortly after the debridement surgery until the 11th day when all the similar systemic and local symptoms recurred. With a remedial crystal analysis of synovial fluid from the patient, gouty flare was found to be the cause of acute arthritis finally. Accor-dingly, after anti-gout medications were administrated, the symptoms associated with acute arthritis gra- dually subsided, and there was no recurrence during a 24-month follow-up. This article described the cli-nical manifestation, diagnosis and differential diagnosis, treatment of a case of periprosthetic gout. Although relatively rare, gout should be considered as a differential diagnosis in suspected periprosthetic infection. Current criteria for periprosthetic infection can not exclude the diagnosis of periprosthetic gout flare, it is therefore imperative that the analysis of joint aspirate for crystals be conducted to determine the correct course of treatment, or unnecessary surgical procedure may be performed in periprosthetic gout case.