Hip Reconstruction In Situ with Screws and Cement (HiRISC) construct to treat large acetabular bone defects.

Aims: Large bone defects resulting from osteolysis, fractures, osteomyelitis, or metastases pose significant challenges in acetabular reconstruction for total hip arthroplasty. This study aimed to evaluate the survival and radiological outcomes of an acetabular reconstruction technique in patients at high risk of reconstruction failure (i.e. periprosthetic joint infection (PJI), poor bone stock, immunosuppressed patients), referred to as Hip Reconstruction In Situ with Screws and Cement (HiRISC). This involves a polyethylene liner embedded in cement-filled bone defects reinforced with screws and/or plates for enhanced fixation. Methods: A retrospective chart review of 59 consecutive acetabular reconstructions was performed by four surgeons in a single institution from 18 October 2018 to 5 January 2023. Cases were classified based on the Paprosky classification, excluding type 1 cases (n = 26) and including types 2 or 3 for analysis (n = 33). Radiological loosening was evaluated by an orthopaedic surgeon who was not the operating surgeon, by comparing the immediate postoperative radiographs with the ones at latest follow-up. Mean follow-up was 557 days (SD 441; 31 to 1,707). Results: Out of the 33 cases analyzed, six (18.2%) constructs required revision, with four revisions due to uncontrolled infection, one for dislocation, and one for aseptic loosening. Among the 27 non-revised constructs, only one showed wider radiolucencies compared to immediate postoperative radiographs, indicating potential loosening. Patients who underwent revision (n = 6) were significantly younger and had a higher BMI compared to those with non-revised constructs (p = 0.016 and p = 0.026, respectively). Sex, race, ethnicity, American Society of Anesthesiologists grade, infection status (patients with postoperative PJI diagnosis (septic) vs patients without such diagnosis (aseptic)), and mean follow-up did not significantly differ between revised and non-revised groups. Conclusion: The HiRISC technique may serve as a feasible short-term (about one to two years) alternative in patients with large acetabular defects, particularly in cases of PJI. Longer follow-up is necessary to establish the long-term survival of this technique.

The Utility of Flap Coverage for Limb Salvage in Patients With Severe Prosthetic Joint Infections of the Knee Requiring Implant Exchange.

BACKGROUND: Prosthetic joint infection (PJI) is a challenging complication of knee arthroplasty, which can require amputation in severe cases. This study analyzes the utility of flap reconstruction in PJIs requiring hardware removal and extensive soft tissue debridement. METHODS: This was a retrospective analysis of patients who were treated according to a multistage extremity salvage protocol between 2018 and 2022. The protocol involved at least 3 planned surgeries including (1) hardware removal with antibiotic spacer placement and soft tissue debridement, (2) spacer exchange with flap coverage, and (3) hardware reimplantation with simultaneous or delayed extensor mechanism reconstruction. All patients had large periprosthetic tissue defects that would necessitate an amputation if not reconstructed. Primary outcomes were extremity salvage and successful defect coverage. RESULTS: Fifty-two patients (25 female) underwent 62 reconstructions (52 primary, 10 salvage). Flap techniques included pedicled muscular (n = 32), fasciocutaneous (n = 4), combined muscular and fasciocutaneous (n = 2), and free flaps (n = 24). Overall rate of successful defect coverage was 95% (98% in primary and 80% in salvage reconstructions). At a median follow-up of 11 months, 41 patients completed the treatment protocol with a 68% (n = 28) extremity salvage rate (reimplantation arthroplasty, n = 15; permanent knee fusion, n = 13). On the multivariate model including demographic factors, defect size, and flap type, no single factor independently predicted limb salvage. CONCLUSIONS: Alongside intensive orthopedic surgical treatment, flap coverage may aid in extremity salvage in severe knee PJIs by reestablishing healthy soft tissue coverage and allowing reimplantation arthroplasty. We recommend a multispecialty approach including plastic surgeons for this challenging condition.

Does Performance of D-Dimer for Diagnosis of Periprosthetic Joint Infection Change With the Virulence of Infecting Organism?

BACKGROUND: The impact of the organism virulence on diagnostic accuracy of D-Dimer for periprosthetic joint infection (PJI) is unknown. Our objective was to assess if the performance of D-Dimer in PJI diagnosis changes with the virulence of the organism(s). METHODS: We retrospectively reviewed 143 consecutive revision total hip arthroplasties/total knee arthroplasties with D-Dimer ordered preoperatively. Operations were performed by 3 surgeons at a single institution (November 2017 through September 2020). There were 141 revisions with complete 2013-International Consensus Meeting-criteria initially included. This criteria was used to classify revisions as aseptic versus septic. Culture-negative septic revisions (n = 8) were excluded, and 133 revisions (47-hips/86-knees; 67-septic/66-aseptic) were analyzed. Based on culture results, septic-revisions were categorized into 'low-virulence (LV/n = 40)' or 'high-virulence (HV/n = 27)'. The D-Dimer threshold (850-ng/mL) was tested against 2013-International Consensus Meeting-criteria ("standard") in identifying septic-revisions (LV/HV) from aseptic-revisions. Sensitivity, specificity, and positive predictive values/negative predictive values (NPV) were determined. Receiver-operating-characteristic-curve-analyses were performed. RESULTS: Plasma D-Dimer showed high sensitivity (97.5%) and NPV (95.4%) in LV septic cases, which appeared to reduce by about 5% in HV septic cases (sensitivity = 92.5% and NPV = 91.3%). However, this marker had poor overall accuracy (LV = 57%; HV = 49.4%), low specificity (LV and HV = 31.8%), and positive predictive values (LV = 46.4%; HV = 35.7%) to diagnose PJI. The area under the curve was 0.647 and 0.622 in LV and HV versus aseptic revisions, respectively. CONCLUSION: D-Dimer performs poorly to identify septic from aseptic revisions in the setting of LV/HV infecting organisms alike. However, it shows high sensitivity for PJI diagnosis in cases of LV organisms which might be missed by most diagnostic tests.

Extended Oral Antibiotic Prophylaxis After Aseptic Total Hip or Knee Arthroplasty Revisions: A Preliminary Report.

BACKGROUND: It is unknown whether extended oral antibiotic (EOA) prophylaxis reduces periprosthetic joint infection (PJI) rates after aseptic revision total hip (THA) and knee arthroplasty (TKA). The literature is scarce. Therefore, we sought to ascertain whether EOA prophylaxis decreases PJI rates after aseptic first-time revision THA and TKA when compared to standard prophylaxis. METHODS: This is a retrospective review of 328 consecutive revisions (3 surgeons, single institution, from September 27, 2017 to December 31, 2019). Preoperative 2013 Musculoskeletal Infection Society (MSIS) criteria, radiographs, and medications were reviewed. Inclusion criteria included aseptic first-time revision THA and TKA. Exclusion criteria were positive intraoperative cultures and/or histology, PJI (2013 MSIS criteria), hemiarthroplasty/partial arthroplasty revision, revision using foreign material (ie, mesh), metastatic bone disease, and intravenous antibiotics >24 hours after surgery. A total of 178 revisions were included, and 2 groups were set apart based on antibiotic prophylactic regime. The following were the groups: (1) EOA prophylaxis (>24 hours, n = 93) and (2) standard prophylaxis (≤24 hours, n = 85). Demographics, joint types, lengths of stay, skin-to-skin operative times, revision types, transfusions, discharge dispositions, and PJIs (per 2013 MSIS criteria) after the first-time revision were compared between groups. There were no significant differences in demographics. However, skin-to-skin operative time was significantly higher in the EOA group (123 minutes versus 98 minutes, P = .01). Mean follow-up was 849 days (range, 15-1,671). Statistical significance was set at a P value lower than .05. RESULTS: Postoperative PJI rates were not significantly different: 2.2% EOA prophylaxis versus 3.5% standard prophylaxis (P = .671). CONCLUSION: No significant difference was found between PJI rates between both prophylactic regimens. A large multicenter study with a larger sample size is needed to support EOA after aseptic revisions. LEVEL OF EVIDENCE: Level III.

Paradoxical Behavior of Plasma d-Dimer From Explantation to Reimplantation in a Two-Stage Revision for Periprosthetic Joint Infection.

BACKGROUND: The variation of plasma d-dimer, an inflammatory marker, from pre-explantation to pre-reimplantation in two-stage revision remains unclear. Our objective was to evaluate delta-changes (Δ) in d-dimer, erythrocyte sedimentation rate (ESR), and C-reactive-protein (CRP), to ascertain whether these delta-changes are associated with the outcome of reimplantation. We hypothesized a decrease in d-dimer before reimplantation. METHODS: A retrospective review was performed on a consecutive series of 95 two-stage revisions indicated for periprosthetic joint infection. Surgeries were performed by 3 surgeons at a single institution (2018-2020). The minimum follow-up was 1 year. The inclusion criteria comprised availability of d-dimer results at pre-explantation and pre-reimplantation. As a result, only 30 reimplantations were included. Success of reimplantation was defined by Musculoskeletal Infection Society outcome reporting tool: Tier 1/Tier 2 vs Tier 3/Tier 4. Nonparametric tests and Mann-Whitney U-tests were conducted to compare Δd-dimer% (pre-explantation value - pre-reimplantation value/pre-explantation value × 100). The bootstrapped receiver operating characteristic curve analyses with 2,000 replicates of 30 cases were conducted. RESULTS: The median time between explantation and reimplantation was 86 days (interquartile range [IQR] = 77.7-138.5 days). Overall, a paradoxical median percent increase (Δd-Dimer% [INCREMENT] = 12.6%) in d-dimer was found from pre-explantation to pre-reimplantation (IQR = -28.06% to 77.3%). However, there was a percentage decrease in ESR (ΔESR% [DECREMENT] = -40%; IQR = -70.52% to 3.85%) and CRP (ΔCRP% [DECREMENT] = -75%; IQR = -87.43% to -61.34%). The changes in all these markers were not different between Musculoskeletal Infection Society Tier 1/2 and 3/4 outcomes (Δd-Dimer%, P = .146; ΔESR%, P = .946; ΔCRP%, P = .463). With area under curve of 0.676, Δd-dimer% (INCREMENT) appeared to be performing best in diagnosing infection control, which was nonexplanatory. CONCLUSION: Plasma d-dimer paradoxically increases before reimplantation while other inflammatory markers (ESR/CRP) decrease, emphasizing that surgeons shall adopt caution using d-dimer to make clinical decisions.

Synovial White Blood Cell Count and Differential to Predict Successful Infection Management in a Two-Stage Revision.

BACKGROUND: An array of synovial white blood cell (WBC) count and polymorphonuclear differential (PMN%) thresholds have been reported using 2013 Musculoskeletal Infection Society (MSIS) definition which has a poor accuracy to confirm infection control before reimplantation. The workgroup of MSIS recently developed a comprehensive definition of successful infection management. Our objectives were to determine optimal thresholds for WBC count and PMN% associated with reimplantation success based on this new MSIS definition and assess if values above these thresholds indicate decreased survival time. METHODS: A retrospective review was conducted on a consecutive series of 133 two-stage hip/knee arthroplasties performed by 15 surgeons (2014-2020) at 2 institutions. All surgeries had a minimum follow-up of 1 year. The inclusion criteria included reporting of preoperative synovial fluid aspiration results. Thus, 88 were finally included. Surgical success was defined by MSIS outcome reporting tool (Tiers 1-4). Receiver operating characteristic curve analyses were performed to estimate optimal thresholds of WBC count and PMN%. A Kaplan-Meier survival analyses with log-rank test were performed. RESULTS: With area under the curve of 0.65, synovial PMN% showed superior accuracy than WBC count (area under the curve = 0.52) in determining outcome of reimplantation. The optimal PMN% threshold (62%) demonstrated sensitivity of 57% and specificity of 77%. The calculated WBC count threshold (2,733/µL) showed poor sensitivity (21%) but high specificity (95%). There was a significant difference in failure-free survival (24 months) between the cases with WBC count higher vs lower than 2,733/µL (P = .002). This was also true for PMN% at 5 months postoperatively (P = .009). CONCLUSION: WBC count (2,733/µL) shows very high specificity to confirm successful reimplantation. Both WBC count and PMN% (62%) thresholds can significantly determine reimplantation survival.

A major increase of thromboembolic events in total hip and knee arthroplasty patients during the COVID-19 pandemic.

OBJECTIVES: The first known COVID-19 patient in the United States was reported on 1/20/2020. Since then, we noted increased thromboembolic events among our THA/TKA patients. Therefore, we sought to determine: (1) monthly incidences of pulmonary embolism (PE)/deep vein thrombosis (DVT) before and after January/2020 and (2) thromboembolic event rates for primary and revision patients. METHODS: We retrospectively obtained from our electronic-medical-records the total monthly number of patients (December/2018-March/2021) who underwent primary or revision THA/TKA, and among them, those who had PE/DVT during each month. Monthly rates of thromboembolic events were calculated and figures were created showing rates throughout time. The cutoff month to define before and after COVID-19 was January/2020. RESULTS: During the study period, 1.6% of patients (312/19068) had PE/DVT [PE (n = 102), DVT (n = 242), both (n = 32)]. Overall rate of PE/DVT before January/2020 was 1.2% (119/9545) and it was 2.0% (193/9523) after that month. Incidences of PE/DVT on April/June/July of 2020 were 3.4%, 3%, 3.4%, respectively. A major increase, when compared to 2019 (1.3%, 1%, 1%, respectively). An unusually high rate of PE was observed on April/2020 (3.4%), more than three times the one observed in any other month. After January/2020, there was an overall major increase of PE/DVT rates, but particularly among revision patients: 6% in five different months including 11.5% on November/2020. CONCLUSION: There was a major increase of thromboembolic events among THA/TKA patients during the COVID-19 pandemic, predominantly in revision patients. Patients need counseling about this increased risk. It remains uncertain whether more aggressive thromboprophylactic regimes should be followed.

The Fate of Periprosthetic Joint Infection With Corynebacterium striatum: A Rare but Catastrophic Causative Organism.

BACKGROUND: The virulence and antibiotic resistance profile of an infecting organism have been shown to impact the outcomes of periprosthetic joint infection (PJI). However, there are no existing data on the outcomes of PJI caused by Corynebacterium striatum, a rare organism. Thus, our objective is to ascertain: (1) the treatment success of PJI caused by this rare organism and (2) patient characteristics in the setting of C striatum PJI. METHODS: A retrospective review was conducted on 741 consecutive PJIs managed at 2 hospital facilities by 8 surgeons (February 4, 2015 to October 30, 2019). The inclusion criteria represented the presence of minimum 1 positive culture of C. striatum. After excluding 1 patient with no follow-up, 15 patients were finally analyzed (9 hips/6 knees). Out of 15 patients, 9 underwent explantation with spacer insertion, 5 underwent irrigation and debridement with polyexchange (I&D), and 1 underwent Girdlestone. Out of 9 explanted patients, only 6 cleared infection and were reimplanted. The clinical staging system for PJI was determined using McPherson classification. The mean follow-ups for I&D and explantation were 35 and 23.5 months, respectively. Success of reimplantation was determined using Delphi criteria. RESULTS: Out of 5 I&D patients, 40% had to be reoperated because of persistent infection. Out of 6 explanted patients who were reimplanted, 67% failed. According to McPherson, 40% of I&D and 22.2% of explanted patients were significantly compromised hosts. CONCLUSION: C. striatum PJI has a high-treatment failure rate in patient undergoing I&D or 2-stage revision surgery. Surgeons should be aware of the difficulty controlling this PJI and advise patients accordingly.

Florida State Opioid Prescription Restriction Law: Impact on Opioid Utilization After Total Joint Arthroplasty.

BACKGROUND: In response to the opioid epidemic, Florida recently passed the opioid prescription limiting law, effective since July 1st, 2018. However, its impact on opioid prescription after total joint arthroplasty (TJA) has not been elucidated. Thus, our objective was to assess if this new law led to reduced opioid prescription after TJA and to determine its impact on perioperative clinical outcomes. METHODS: A retrospective chart review was conducted on a consecutive series of 658 primary TJAs (618 patients), performed by four surgeons in a single institution [1/2/2018-10/23/2018]. Based on effective date of the law, cases were divided into: prelaw (327 cases; 168 hips/159 knees) and postlaw (331 cases; 191 hips/140 knees) phases. Baseline demographics and surgical characteristics were compared. The effect of the law on perioperative outcomes: length of stay, complications, emergency department/office visits, patient phone calls, reoperation or readmission (90 days), and total morphine equivalents prescribed was investigated. Independent sample t-tests and chi-square analyses were performed. RESULTS: Prelaw and postlaw phases had no significant difference in baseline demographics and characteristics. No difference was found in length of stay. Opioid law implementation led to significantly lower total oral morphine equivalents after TJAs [Prelaw: 1059.9 ± 825.4 vs postlaw: 942.8 ± 691.7; P = .04], but did not result in a significant increase in 90-day complications, patient visits (office or emergency) or phone calls, and reoperation or readmission. CONCLUSION: Our data suggest that Florida state opioid prescription limiting law has resulted in a marked decline in opioid prescription without any increase in rates of patient visits, phone calls, or readmission after TJA.

Plasma D-dimer Does Not Anticipate the Fate of Reimplantation in Two-stage Exchange Arthroplasty for Periprosthetic Joint Infection: A Preliminary Investigation.

BACKGROUND: Inflammatory markers such as the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels have always been a part of the diagnostic criteria for periprosthetic joint infection (PJI), but they perform poorly anticipating the outcome of reimplantation. D-dimer has been reported in a small series as a potential marker to measure infection control after single-stage revisions to treat PJI. Nonetheless, its use to confirm infection control and decide the proper timing of reimplantation remains uncertain. QUESTIONS/PURPOSES: (1) What is the best diagnostic threshold and accuracy values for plasma D-dimer levels compared with other inflammatory markers (ESR and CRP) or what varying combinations of these tests are associated with persistent infection after reimplantation? (2) Do D-dimer values above this threshold, ESR, CRP, and varying test combinations at the time of reimplantation indicate an increased risk of subsequent persistent infection after reimplantation? METHODS: We retrospectively studied the electronic medical records of all 53 patients who had two-stage revisions for PJI and who underwent plasma D-dimer testing before reimplantation at one of two academic institutions from November 22, 2017 to December 5, 2020. During that period, all patients undergoing two-stage revisions also had a D-dimer test drawn. The minimum follow-up duration was 1 year. We are reporting at this early interval (rather than the more typical 2-year time point) because of the poorer-than-expected performance of this diagnostic test. Of these 53 patients, 17% (9) were lost to follow-up before 1 year and could not be analyzed; the remaining 44 patients (17 hips and 27 knees) were studied here. The mean follow-up was 503 ± 135 days. Absence or persistence of infection after reimplantation were defined according to the Delphi criteria. The conditions included in these criteria were: (1) control of infection, as characterized by a healed wound without fistula, drainage, or pain; (2) no subsequent surgical intervention owing to infection after reimplantation; and (3) no occurrence of PJI-related mortality. The absence of any of the aforementioned conditions until the final follow-up examination was deemed a persistent infection after reimplantation. Baseline patient characteristics were not different between patients with persistent infection (n = 10) and those with absence of it after reimplantation (n = 34) as per the Delphi criteria. Baseline patient characteristics evaluated were age, gender, self-reported race (white/Black/other) or ethnicity (nonHispanic/Hispanic), BMI, American Society of Anesthesiologists (ASA) status, smoking status(smoker/nonsmoker), and joint type (hip/knee). The optimal D-dimer threshold to differentiate between persistence of infection or not after reimplantation was calculated using the Youden index. A receiver operating characteristic curve analysis was performed to test the accuracy of D-dimer, ESR, CRP, and their combinations to establish associations, if any, with persistent infection after reimplantation. A Kaplan-Meier survival analysis (free of infection after reimplantation) with a log-rank test was performed to investigate if D-dimer, ESR, and CRP were associated with absence of infection after reimplantation. Survival or being free of infection after reimplantation was determined as per Delphi criteria. Alpha was set at p < 0.05. RESULTS: In the receiver operating characteristic curve analysis, with an area under the curve of 0.62, D-dimer showed low accuracy and did not anticipate persistent infection after reimplantation. The optimal D-dimer threshold differentiating between persistence of infection or not after reimplantation was 3070 ng/mL. When using this threshold, D-dimer demonstrated a sensitivity of 90% (95% CI 55.5% to 99.7%) and negative predictive value of 94% (95% CI 70.7% to 99.1%), but low specificity (47% [95% CI 29.8% to 64.9%]) and positive predictive value (33% [95% CI 25.5% to 42.2%]). Although D-dimer showed the highest sensitivity, the combination of D-dimer with ESR and CRP showed the highest specificity (91% [95% CI 75.6% to 98%]) defining the persistence of infection after reimplantation. Based on plasma D-dimer levels, with the numbers available, there was no difference in survival free from infection after reimplantation (Kaplan-Meier survivorship free from infection at minimum 1 year in patients with D-dimer below 3070 ng/mL versus survivorship free from infection with D-dimer above 3070 ng/mL: 749 days [95% CI 665 to 833 days] versus 615 days [95% CI 471 to 759 days]; p = 0.052). Likewise, there were no associations between high ESR and CRP levels and persistent infection after reimplantation, but the number of events was very small, and insufficient power is a concern with this analysis. CONCLUSION: In this preliminary series, with the numbers available, D-dimer alone had poor accuracy and was not associated with survival free from infection after reimplantation in patients who underwent two-stage exchange arthroplasty. D-dimer alone might be used to establish that PJI is unlikely, and the combination of D-dimer, ESR, and CRP should be considered to confirm PJI diagnosis in the setting of reimplantation.Level of Evidence Level IV, diagnostic study.

Direct Anterior Approach for Total Hip Arthroplasty with Subtrochanteric Shortening Osteotomy: A Case Report.

CASE: A patient with Aitken type A proximal focal femoral deficiency (PFFD) and significant limb length discrepancy managed with total hip arthroplasty making use of a novel technique that features a direct anterior approach (DAA) and a subtrochanteric shortening osteotomy. CONCLUSION: Although the current description of the shortening osteotomy is for PFFD, it is versatile enough to allow its application in other hip pathologies requiring subtrochanteric shortening in the setting of total hip arthroplasty. The authors believe that the description of this case report and surgical technique may be an option for the experienced DAA surgeon.

Irrigation and Debridement with Chronic Antibiotic Suppression Is as Effective as 2-Stage Exchange in Revision Total Knee Arthroplasty with Extensive Instrumentation.

BACKGROUND: Extraction of implants because of periprosthetic infection (PJI) following complex revision total knee arthroplasty (rTKA) with extensive instrumentation is a daunting undertaking for surgeon and patient alike. The purpose of the present study was to evaluate whether infections following complex rTKA are better treated with 2-stage exchange or irrigation and debridement (I&D) with modular component exchange and antibiotic suppression in terms of infection control, reoperation, and function. METHODS: We reviewed rTKAs that had been performed for the treatment of PJI from 2005 to 2016. Extensive instrumentation was defined as the presence ≥1 of the following: metaphyseal cones/sleeves, distal femoral replacement, periprosthetic fracture instrumentation, or fully cemented stems measuring >75 mm. Cases were categorized according to the initial treatment (I&D with antibiotic suppression or initiation of 2-stage exchange). RESULTS: Eighty-seven patients with PJI and extensive instrumentation were identified: 56 patients who were managed with I&D with suppression and 31 who were managed with the initiation of 2-stage exchange. The rate of success (defined as no reoperation for infection) was similar for the 2 groups (62.5% the I&D group compared with 67.7% for the 2-stage group; p = 0.62). The rate of mortality was also similar (39.3% for the I&D group compared with 38.7% for the 2-stage group; p = 0.96). Of the 31 patients in the 2-stage group, 18 (58.1%) underwent reimplantation with a revision replacement. Of those 18 patients, 13 were still infection-free at the time of the most recent follow-up; however, when the analysis was expanded to all 31 patients in the 2-stage group, only 13 (41.9%) both had a successful reimplantation and did not require additional surgery for infection. Nine (29.0%) of the 31 patients in the 2-stage group never underwent the second stage, and 4 (12.9%) of the 31 required arthrodesis at the second stage. In contrast, 35 (62.5%) of the 56 patients in the I&D group were successfully managed, without additional surgery for the treatment of infection. At the time of the latest follow-up (mean, 3.2 years; range, 2 to 13 years), more patients in the I&D group were ambulatory (76.8% in the I&D group compared with 54.8% in the 2-stage group; p = 0.05) and maintained a functional bending knee joint (85.7% in the I&D group compared with 45.2% in the 2-stage group; p < 0.001). CONCLUSIONS: In the treatment of periprosthetic infection of rTKA with extensive instrumentation, I&D with chronic antibiotic suppression was as effective as 2-stage exchange in terms of preventing reoperation for infection and was more effective in terms of maintaining function. These data apply to rTKA with extensive periarticular instrumentation and should not be extrapolated to primary or simple revision implants. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Meta-analysis Comparing Allograft to Synthetic Reconstruction for Extensor Mechanism Disruption after Total Knee Arthroplasty.

Extensor mechanism disruption following total knee arthroplasty (TKA) is a devastating complication that causes high failure rates. There is controversy on what is the best way to do an extensor mechanism reconstruction. This study aims to compare both allograft and synthetic reconstructive techniques for success, reoperation, and infection rates and functional outcomes. The search on PubMed, MEDLINE, Embase, BIOSIS, and Cochrane databases was performed on March 15, 2019, using the following keyword groups: (1) "extensor mechanism" and "total knee arthroplasty," (2) "extensor mechanism" and "knee arthroplasty," (3) "extensor mechanism" and "revision total knee arthroplasty," and (4) "extensor mechanism" and "revision knee arthroplasty". Only studies on extensor mechanism disruption after TKA that included sufficient data to compare these two surgical techniques were included. Meta-analysis was performed with random effect model using the DerSimonian-Laird method. Thirty studies were included. The overall success rate of the reconstruction was 73.3% (95% confidence interval [CI]: 0. 651, 0.814). The success rate of allograft (72.8%, 95% CI: 0.626, 0.829) was not significantly different from synthetic material (78%, 95% CI: 0.707, 0.852, p = 0.416). There was no significant difference in revision rates between allograft (14.2%, 95% CI: 0.095, 0.189) and synthetic material (16%, 95% CI: 0.096, 0.223, p = 0.657). The overall relative risk of infection was 4.301 (95% CI: 1.885, 9.810). There was no significant difference in relative risk of infection between allograft (3.886, 95% CI: 1.269, 11.903) and synthetic material (4.851, 95% CI: 1.433, 16.419, p = 0.793). No statistically significant difference was found in mean postoperative Knee Society score (73.109 [95% CI: 67.296, 78.922] vs. 72.679 [95% CI: 69.184, 76.173], p = 0.901) between allograft and mesh reconstruction groups. There were no significant differences in overall failures, infections, functional outcomes, or revision reconstructions between allograft and synthetic material extensor mechanism reconstructions. Our results demonstrate the difficulty in treating this serious injury, independent of technique, as well as the significant risk for overall failure and infection.

Vancomycin Powder and Dilute Povidone-Iodine Lavage for Infection Prophylaxis in High-Risk Total Joint Arthroplasty.

BACKGROUND: Dilute povidone-iodine lavage has been shown to be safe and effective in decreasing acute periprosthetic joint infection (PJI) following total joint arthroplasty (TJA). Vancomycin powder is reported to be effective in preventing infection in spine surgery. We hypothesize that a "vanco-povidone protocol" (VIP) for TJA patients at high risk for infection is safe and will decrease the rate of PJI. METHODS: High-risk TJA patients (body mass index >40, active smokers, American Society of Anesthesiologists ≥3, immunosuppression/diabetes, methicillin-resistant Staphylococcus aureus colonization, revision surgery) utilizing VIP were compared to a high-risk historical cohort not treated with VIP, at a single institution. VIP consisted of dilute povidone-iodine lavage followed by application of vancomycin powder prior to wound closure. Primary endpoint was PJI within 3 months postoperatively. RESULTS: The historical, high-risk control cohort consisted of 3251 patients with a PJI incidence of 1.8%. A total of 1413 subjects received the VIP protocol with a PJI incidence of 1.3%. There was a 27.8% risk reduction when compared to the control group of high-risk subjects not treated with the VIP. There were no medical complications secondary to the use of VIP, no increase in vancomycin-resistant enterococcus or vancomycin-resistant Staph aureus, and no cases of acute renal impairment secondary to application of the local vancomycin. CONCLUSIONS: PJI remains a common complication of TJA, especially in high-risk populations. This study indicates that a protocol of dilute povidone-iodine lavage combined with topical vancomycin powder is safe and may reduce PJI incidence in high-risk TJA patients. Due to low, current PJI rates, a multi-institutional randomized controlled trial is necessary to assess interventions that minimize the risk of PJI. LEVEL OF EVIDENCE: Retrospective Observational Cohort.

The treatment of periprosthetic joint infection: safety and efficacy of two stage versus one stage exchange arthroplasty.

Introduction: Periprosthetic joint infection (PJI) remains one of the most dreaded and challenging complications in adult reconstruction. While primary total joint arthroplasty is one of the most successful surgeries in medicine, revisions secondary to infections do not hold as well. As the number of primary procedures increases, so will infections. In North America, two-stage exchange arthroplasty is the standard of care for patients with PJI, especially when the presentation is greater than 4 weeks after the index procedure. However, it is not necessarily the best option for all patients, particularly when compared to one-stage arthroplasty.Areas covered: The aim of this review is to analyze the indications, safety, and efficacy of two-stage exchange arthroplasty for the treatment of PJI and to compare the results reported 10 years ago with the ones of recent publications and those of one-stage arthroplasty.Expert opinion: Two-stage exchange arthroplasty is a safe and efficacious treatment particularly suited for recalcitrant infections, resistant organisms, and patients with certain host factors that make it more difficult to eradicate infection. However, one-stage arthroplasty might be well suited as well for infections caused by susceptible organisms and patients with minimal or no comorbidities or those unable to undergo two surgeries.

The Utility of Serum d-Dimer for the Diagnosis of Periprosthetic Joint Infection in Revision Total Hip and Knee Arthroplasty.

BACKGROUND: There is scarce and contradicting evidence supporting the use of serum d-dimer for the diagnosis of periprosthetic joint infection in revision total hip (THA) and knee (TKA) arthroplasty. Therefore, the purpose of this study is to test the accuracy of serum d-dimer against the 2013 International Consensus Meeting (ICM) criteria. METHODS: A retrospective review was performed on a consecutive series of 172 revision THA/TKA surgeries performed by 3 fellowship-trained surgeons at a single institution (August 2017 to May 2019) and that had d-dimer performed during their preoperative workup. Of this cohort, 111 (42 THAs/69 TKAs) cases had complete 2013 ICM criteria tests and were included in the final analysis. Septic and aseptic revisions were categorized per 2013 ICM criteria ("gold standard") and compared against serum d-dimer using an established threshold (850 ng/mL). Sensitivity, specificity, likelihood ratios, and positive/negative predictive values were determined. Independent t-tests, Fisher's exact tests, chi-squared tests, and receiver operating characteristic curve analysis were performed. RESULTS: There was no statistically significant difference in baseline demographics between septic and aseptic cases per 2013 ICM criteria. When compared to ICM criteria, d-dimer demonstrated high sensitivity (95.9%) and negative predictive value (90.9%) but low specificity (32.3%), positive predictive value (52.8%), and overall, poor accuracy (61%) to diagnose periprosthetic joint infection. Positive likelihood ratio was 1.42 while negative likelihood ratio was 0.13. The area under the curve (AUC) was 0.742. CONCLUSION: Serum d-dimer has poor accuracy to discriminate between septic and aseptic cases using a described threshold in the setting of revision THA and TKA.

Evolution of Diagnostic Definitions for Periprosthetic Joint Infection in Total Hip and Knee Arthroplasty.

Various definitions and biomarkers have been developed in an unsuccessful attempt to obtain a "gold standard" for periprosthetic joint infection (PJI) diagnosis. The development of the 2011 Musculoskeletal Infection Society criteria facilitated further research and advances by allowing the use of a consistent PJI definition across studies. The newly proposed 2018 criteria do not rely at all on expert opinions/consensus. In this review, we describe the most relevant definitions developed throughout recent time, their rationale, characteristics, and supportive evidence for their clinical implementation. In the opinion of the authors, the orthopedic community should consider a probability and likelihood paradigm to create a PJI diagnostic definition. Probably not a single definition might be suited for all situations; the inclusion of serological findings could be the next step moving forward.

Serum D-Dimer in the Diagnosis of Periprosthetic Knee Infection: Where Are We Today?

Periprosthetic joint infection (PJI) continues to impact a remarkable number of patients who undergo total knee arthroplasty (2.0-2.1%). Substantial efforts to curtail these rates have been seen in the past decade including various attempts to reach a clear definition of PJI that the orthopaedic community could adopt as a gold standard. The Musculoskeletal Infection Society (MSIS) criteria, slightly modified by the International Consensus Meeting (ICM), has gained widespread acceptance and it is a step closer to that goal. Research on markers such as serum cross-linked D-fragments (D-dimer) seems promising in the diagnosis of infection. In the setting of PJI, a recent publication has established a threshold of 850 ng/mL as the optimal cutoff value for serum D-dimer. Therefore, our objective is to present a summary of the current literature on the changing indications of D-dimer and its rising importance in the setting of PJI. Serum D-dimer has been shown to outperform other conventional tests such as erythrocyte sedimentation rate and C-reactive protein that have been a major part of the ICM criteria and it has been included in the newly proposed diagnostic criteria for PJI that correctly diagnoses infection in 95.5% of septic patients (overall sensitivity: 97.7%, specificity: 99.5%). In comparison with the ICM and MSIS infection definitions, the new criteria revealed a higher sensitivity (97.7 vs. 86.9% and 97.7 vs. 79.3%, respectively), while specificity was similar. In conclusion, high D-dimer levels in primary or revision knee arthroplasty seem indicative of diagnosis of PJI. However, future studies are warranted to conclusively support the routine use of this marker and to validate the performance of the newly developed PJI diagnostic criteria under different clinical scenarios.

Dual Antibiotic Prophylaxis in Total Knee Arthroplasty: Where Do We Stand?

The risk of surgical site infection in primary total knee arthroplasty (TKA) has been reduced with the use of prophylactic antibiotics. First or second generation cephalosporins are still recommended as the primary prophylactic choice, but with the rise in the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections, evidence has emerged in favor of using dual antibiotics including vancomycin. However, it is unclear whether these combinations of antibiotic regimens further reduce postoperative infection rates. As a result, the objective of this review is to summarize the current literature concerning the use of dual prophylactic antibiotics in TKA. The most common dual prophylactic antibiotic combination is cefazolin (C) and vancomycin (V). In general, when comparing the effectiveness of single versus dual antibiotics, conflicting results have been reported. Three studies demonstrated no substantial decrease in overall postoperative infection rates with the use of dual antibiotics when compared with cefazolin alone. One found a significant decrease only in MRSA infection rates when using cefazolin and vancomycin (CV) (0.8% C alone vs. 0.08% CV, p < 0.05). Another investigation evaluated revision TKA patients who had combined cefazolin and vancomycin prophylaxis and showed a significant decline in both overall infection (7.89% [C] vs. 3.13% [CV]) and MRSA infection rates (4.21% [C] vs. 0.89% [CV]; p < 0.05). Concerning the safety profile of dual antibiotics, particular precautions must be adopted with the use of vancomycin because of the risk of acute kidney injury. Instead of vancomycin, an alternate less nephrotoxic antibiotic option might be teicoplanin. Unfortunately, this latter agent is only available outside of the United States. In conclusion, the value of dual antibiotic prophylaxis for the prevention of periprosthetic knee infections remains unclear primarily because all comparative studies performed between dual and single antibiotics have been of low evidence with retrospective designs. Larger multicenter randomized controlled trials are warranted.