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.

Stepping Up Recovery: Integrating Patient-reported Outcome Measures and Wearable Technology for Rehabilitation Following Knee Arthroplasty.

Improvement after knee arthroplasty (KA) is often measured using patient-reported outcome measures (PROMs). However, PROMs are limited due to their subjectivity. Therefore, wearable technology is becoming commonly utilized to objectively assess physical activity and function. We assessed the correlation between PROMs and step/stair flight counts in total (TKA) and partial knee arthroplasty (PKA) patients.Analysis of a multicenter, prospective, longitudinal cohort study investigating the collection of average daily step and stair flight counts, was performed. Subjects (N = 1,844 TKA patients and N = 489 PKA patients) completed the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) and provided numerical rating scale pain scores pre- and postoperatively. Only patients who reported living in a multilevel home environment (N = 896 TKA patients and N = 258 PKA patients) were included in analysis of stair flight counts. Pearson correlation coefficients were calculated to determine correlations between variables.Among TKA patients, pain scores demonstrated a negative correlation to mean step counts at preoperative (r = -0.14, p < 0.0001) and 1-month follow-up (r = -0.14, p < 0.0001). Similar negative correlations were true for pain and stair flight counts at preoperative (r = -0.16, p < 0.0001) and 1-month follow-up (r = -0.11, p = 0.006). KOOS JR scores demonstrated weak positive correlations with mean step counts at preoperative (r = 0.19, p < 0.0001) and 1-month postoperative (r = 0.17, p < 0.0001). Similar positive correlations were true for KOOS JR scores and stair flight counts preoperatively (r = 0.13, p = 0.0002) and at 1-month postoperatively (r = 0.10, p = 0.0048). For PKA patients, correlations between pain and KOOS JR with step/stair counts demonstrated similar directionality.Given the correlation between wearable-generated data and PROMs, wearable technology may be beneficial in evaluating patient outcomes following KA. By combining subjective feedback with the objective data, health care providers can gain a holistic view of patients' progress and tailor treatment plans accordingly.

Safety Profile of Seven-Day Intra-articular Antibiotic Irrigation for the Treatment of Chronic Periprosthetic Joint Infection: A Prospective Randomized Phase II Comparative Study.

BACKGROUND: Systemic intravenous antimicrobials yield poor outcomes during treatment of periprosthetic joint infection due to the inability to obtain minimum biofilm eradication concentrations. This study evaluated the safety of a novel method of optimized local delivery of intra-articular antibiotics (IAAs). METHODS: This was a Phase II, multicenter, prospective randomized trial evaluating safety of a rapid (seven-day) two-stage exchange arthroplasty with IAA irrigation compared to standard two-stage exchange. The Experimental Group received irrigation using 80 mg tobramycin daily with a 2-hour soak, followed by hourly irrigation using 125 mg vancomycin with a 30-minute soak via an intramedullary irrigation device. The Control Group received an antibiotic-loaded cement spacer with vancomycin (average 8.4 g) and tobramycin (average 7.1 g, total 16 g antibiotics). Both groups received 12 weeks of systemic antibiotics following Stage 2. Safety measures included adverse events, peak vancomycin/tobramycin serum concentrations (Experimental Group), blood transfusion, and mortality. There were thirty-seven patients randomized to the Experimental Group and 39 to control. There was no difference in baseline demographics or comorbidities. RESULTS: There were no antibiotic medication-related adverse events and 2 serious adverse events related to antibiotic instillation. Of 188 vancomycin peak measurements, 69% had detectable serum level concentrations, with all concentrations well below the maximum acceptable trough threshold of 20 µg/mL. Of the 103 tobramycin peak measurements, 45% had detectable levels, with all below the maximum acceptable peak threshold of 18 to 24 µg/mL. There was no difference in blood transfused per subject (Experimental: 655 mL versus Control: 792 mL; P = .4188). There were two (2) deaths in the Experimental Group and four (4) in the control. CONCLUSIONS: The use of IAA is safe with minimal systemic antibiotic exposure. There was no difference in the rates or severity of serious adverse events between groups. Further research is being conducted to examine treatment efficacy.

What Is the True Impact of Periprosthetic Joint Infection Diagnosis on Mortality?

BACKGROUND: Mortality is a quality indicator that may affect expenditures. Revisions for periprosthetic joint infection (PJI) are, on average, more expensive and exhibit higher morbidity than aseptic revisions, although reimbursement is similar. Therefore, we sought to determine (1) impact on mortality rates of revision total hip and/or knee arthroplasty performed for PJI diagnosis (septic) versus aseptic revisions, at any point in time, and (2) mortality predictors among PJI patients. METHODS: Retrospective chart review of 978 consecutive patients who underwent revision at a single institution (January 2015 to November 2020). All revisions were evaluated, and it was determined whether patients had a revision for PJI at any point in time or not. Two groups were compared: (1) patients with septic revision(s) (n = 350) and (2) patients who only underwent aseptic revision(s) (n = 628). Demographics and mortality status at latest follow-up (mean 3 years, range: 0 to 18 years, from first revision ever) were assessed. Mortality status was also separately assessed among patients who exclusively had hip revision(s), or solely knee revision(s), or both. Multivariate regression analysis (Cox) was used to determine whether PJI diagnosis was an independent mortality predictor. Among PJI patients, potential mortality predictors were evaluated. RESULTS: Overall, 65 patients died (6.6%). The septic cohort had significantly more men and American Society of Anesthesiologists (ASA) class-IV patients. Mortality rates were 10.9% and 4.3% (P < .0001) for septic and aseptic revision groups, respectively. After controlling for sex, ASA, and number of revisions, PJI diagnosis was a significant mortality predictor (hazard ratio [HR]: 2.69, 95% confidence interval [CI]: 1.5 to 4.7, P = .001). Among PJI patients, age (HR: 1.05, 95% CI: 1.01 to 1.08, P = .009) and ASA (HR: 4.02, 95% CI: 1.67 to 9.67, P = .002) were independent predictors. CONCLUSIONS: Having a revision due to PJI diagnosis was associated with 2.5 times increased mortality. Therefore, more accurate coding capturing the complexity and morbidity of revisions for PJI diagnosis is needed.

Impact of Chronic Opioid Use on Postoperative Mobility Recovery and Patient-Reported Outcomes: A Propensity-Matched Study.

BACKGROUND: Opioid use prior to total joint arthroplasty may be associated with poorer postoperative outcomes. However, few studies have reported the impact on postoperative recovery of mobility. We hypothesized that chronic opioid users would demonstrate impaired objective and subjective mobility recovery compared to nonusers. METHODS: A secondary data analysis of a multicenter, prospective observational cohort study in which patients used a smartphone-based care management platform with a smartwatch for self-directed rehabilitation following hip or knee arthroplasty was performed. Patients were matched 2:1 based on age, body mass index, sex, procedure, Charnley class, ambulatory status, orthopedic procedure history, and anxiety. Postoperative mobility outcomes were measured by patient-reported ability to walk unassisted at 90 days, step counts, and responses to the 5-level EuroQol-5 dimension 5-level, compared by Chi-square and student's t-tests. Unmatched cohorts were also compared to investigate the impact of matching. RESULTS: A total of 153 preoperative chronic opioid users were matched to 306 opioid-naïve patients. Age (61.9 ± 10.5 versus 62.1 ± 10.3, P = .90) and sex (53.6 versus 53.3% women, P = .95) were similar between groups. The proportion of people who reported walking unassisted for 90 days did not vary in the matched cohort (87.8 versus 90.7%, P = .26). Step counts were similar preoperatively and 1-month postoperatively but were lower in opioid users at 3 and 6 months postoperatively (4,823 versus 5,848, P = .03). More opioid users reported moderate to extreme problems with ambulation preoperatively on the 5-level EuroQol-5 dimension 5-level (80.6 versus 69.0%, P = .02), and at 6 months (19.2 versus 9.3%, P = .01). CONCLUSIONS: Subjective and objective measures of postoperative mobility were significantly reduced in patients who chronically used opioid medications preoperatively. Even after considering baseline factors that may affect ambulation, objective mobility metrics following arthroplasty were negatively impacted by preoperative chronic opioid use.

The Mark Coventry Award: PhotothermAA Gel Combined With Debridement, Antibiotics, and Implant Retention Significantly Decreases Implant Biofilm Burden and Soft-Tissue Infection in a Rabbit Model of Knee Periprosthetic Joint Infection.

BACKGROUND: Chronic periprosthetic joint infection (PJI) is a major complication of total joint arthroplasty. The underlying pathogenesis often involves the formation of bacterial biofilm that protects the pathogen from both host immune responses and antibiotics. The gold standard treatment requires implant removal, a procedure that carries associated morbidity and mortality risks. Strategies to preserve the implant while treating PJI are desperately needed. Our group has developed an anti-biofilm treatment, PhotothermAA gel, which has shown complete eradication of 2-week-old mature biofilm in vitro. In this study, we tested the anti-biofilm efficacy and safety of PhotothermAA in vivo when combined with debridement, antibiotics and implant retention (DAIR) in a rabbit model of knee PJI. METHODS: New Zealand white rabbits (n = 21) underwent knee joint arthrotomy, titanium tibial implant insertion, and inoculation with Xen36 (bioluminescent Staphylococcus aureus) after capsule closure. At 2 weeks, rabbits underwent sham surgery (n = 6), DAIR (n = 6), or PhotothermAA with DAIR (n = 9) and were sacrificed 2 weeks later to measure implant biofilm burden, soft-tissue infection, and tissue necrosis. RESULTS: The combination of anti-biofilm PhotothermAA with DAIR significantly decreased implant biofilm coverage via scanning electron microscopy compared to DAIR alone (1.8 versus 81.0%; P < .0001). Periprosthetic soft-tissue cultures were significantly decreased in the PhotothermAA with DAIR treatment group (log reduction: Sham 1.6, DAIR 2.0, combination 5.6; P < .0001). Treatment-associated necrosis was absent via gross histology of tissue adjacent to the treatment area (P = .715). CONCLUSIONS: The addition of an anti-biofilm solution like PhotothermAA as a supplement to current treatments that allow implant retention may prove useful in PJI treatment.

Periprosthetic joint infection and immunity: Current understanding of host-microbe interplay.

Periprosthetic joint infection (PJI) is a major complication of total joint arthroplasty. Even with current treatments, failure rates are unacceptably high with a 5-year mortality rate of 26%. Majority of the literature in the field has focused on development of better biomarkers for diagnostics and treatment strategies including innovate antibiotic delivery systems, antibiofilm agents, and bacteriophages. Nevertheless, the role of the immune system, our first line of defense during PJI, is not well understood. Evidence of infection in PJI patients is found within circulation, synovial fluid, and tissue and include numerous cytokines, metabolites, antimicrobial peptides, and soluble receptors that are part of the PJI diagnosis workup. Macrophages, neutrophils, and myeloid-derived suppressor cells (MDSCs) are initially recruited into the joint by chemokines and cytokines produced by immune cells and bacteria and are activated by pathogen-associated molecular patterns. While these cells are efficient killers of planktonic bacteria by phagocytosis, opsonization, degranulation, and recruitment of adaptive immune cells, biofilm-associated bacteria are troublesome. Biofilm is not only a physical barrier for the immune system but also elicits effector functions. Additionally, bacteria have developed mechanisms to evade the immune system by inactivating effector molecules, promoting killing or anti-inflammatory effector cell phenotypes, and intracellular persistence and dissemination. Understanding these shortcomings and the mechanisms by which bacteria can subvert the immune system may open new approaches to better prepare our own immune system to combat PJI. Furthermore, preoperative immune system assessment and screening for dysregulation may aid in developing preventative interventions to decrease PJI incidence.

Combination d-Amino Acid and Photothermal Hydrogel for the Treatment of Prosthetic Joint Infections.

Prosthetic joint infection (PJI) is a devastating complication requiring surgical intervention and prolonged antimicrobial treatment. The prevalence of PJI is on the rise, with an average incidence of 60,000 cases per year and a projected annual cost of $1.85 billion in the US. The underlying pathogenesis of PJI involves the formation of bacterial biofilms that protect the pathogen from the host immune response and antibiotics, making it difficult to eradicate such infections. Biofilms on implants are also resistant to mechanical brushing/scrubbing methods of removal. Since the removal of biofilms is currently only achievable by the replacement of the prosthesis, therapies aimed at eradicating biofilms while enabling retention of implants will revolutionize the management of PJIs. To address severe complications associated with biofilm-related infections on implants, we have developed a combination treatment that is based on a hydrogel nanocomposite system, containing d-amino acids (d-AAs) and gold nanorods, which can be delivered and transforms from a solution to a gel state at physiological temperature for sustained release of d-AAs and light-activated thermal treatment of infected sites. Using this two-step approach to utilize a near-infrared light-activated hydrogel nanocomposite system for thermal treatment, following initial disruption with d-AAs, we were able to successfully demonstrate in vitro the total eradication of mature Staphylococcus aureus biofilms grown on three-dimensional printed Ti-6Al-4V alloy implants. Using a combination of cell assays, computer-aided scanning electron microscopy analyses, and confocal microscopy imaging of the biofilm matrix, we could show 100% eradication of the biofilms using our combination treatment. In contrast, we were only able to see 25% eradication of the biofilms using the debridement, antibiotics, and implant retention method. Moreover, our hydrogel nanocomposite-based treatment approach is adaptable in the clinical setting and capable of combating chronic infections brought about by biofilms on medical implants.

Robotic Arm-Assisted versus Manual Total Knee Arthroplasty: A Propensity Score-Matched Analysis.

The purpose of this study was to compare (1) operative time, (2) in-hospital pain scores, (3) opioid medication use, (4) length of stay (LOS), (5) discharge disposition at 90-day postoperative, (6) range of motion (ROM), (7) number of physical therapy (PT) visits, (8) emergency department (ED) visits, (9) readmissions, (10) reoperations, (11) complications, and (12) 1-year patient-reported outcome measures (PROMs) in propensity matched patient cohorts who underwent robotic arm-assisted (RA) versus manual total knee arthroplasty (TKA). Using a prospectively collected institutional database, patients who underwent RA- and manual TKA were the nearest neighbor propensity score matched 3:1 (255 manual TKA:85 RA-TKA), accounting for various preoperative characteristics. Data were compared using analysis of variance (ANOVA), Kruskal-Wallis, Pearson's Chi-squared, and Fisher's exact tests, when appropriate. Postoperative pain scores, opioid use, ED visits, readmissions, and 1-year PROMs were similar between the cohorts. Manual TKA patients achieved higher maximum flexion ROM (120.3 ± 9.9 versus 117.8 ± 10.2, p = 0.043) with no statistical differences in other ROM parameters. Manual TKA had shorter operative time (105 vs.113 minutes, p < 0.001), and fewer PT visits (median [interquartile range] = 10.0 [8.0-13.0] vs. 11.5 [9.5-15.5] visits, p = 0.014). RA-TKA had shorter LOS (0.48 ± 0.59 vs.1.2 ± 0.59 days, p < 0.001) and higher proportion of home discharges (p < 0.001). RA-TKA and manual TKA had similar postoperative complications and 1-year PROMs. Although RA-TKA patients had longer operative times, they had shorter LOS and higher propensity for home discharge. In an era of value-based care models and the steady shift to outpatient TKA, these trends need to be explored further. Long-term and randomized controlled studies may help determine potential added value of RA-TKA versus manual TKA. This study reflects level of evidence III.

Volume and Outcomes of Joint Arthroplasty.

BACKGROUND: Joint arthroplasties are among the most commonly performed elective surgeries in the United States. Surgical outcomes are known to improve with volume but it is unclear whether this has led to consolidation among elective surgeries. We examined trends in volumes per surgeon and hospital to assess whether the known volume-outcome relationship has led to consolidation in elective joint arthroplasty and to determine if there exist volume thresholds above which outcomes do not change. METHODS: Among Medicare beneficiaries who underwent either total knee or total hip arthroplasty from 2009 through 2015, we described volume trends and used mixed-effect models to relate annual surgeon and hospital volumes with 30-day complications or mortality. We tested for optimal volume cut points at both the hospital and surgeon level. RESULTS: Adjusted annual complication rates were inversely associated with volume for both procedures at both the surgeon level and hospital level, but there was minimal consolidation between 2009 and 2015. Complications no longer declined after volumes of each case exceeded 260 per year. The vast majority of cases (around 93% of hip and 88% of knee arthroplasties) were performed by surgeons operating at suboptimal volumes. CONCLUSION: More than 2 decades after the volume-outcome relationship was established for joint arthroplasty, many cases continue to be performed by low-volume surgeons, with far more cases performed by surgeons operating at suboptimal volumes. Further improvement could be expected through consolidation at both the hospital and surgeon level, with a target of at least 260 cases per surgeon annually for each operation. Payers seem best-equipped to drive consolidation.

Standardized quantification of biofilm in a novel rabbit model of periprosthetic joint infection.

Periprosthetic joint infection (PJI) is one of the most devastating complications of total joint arthroplasty. The underlying pathogenesis involves the formation of bacterial biofilm that protects the pathogen from the host immune response and antibiotics, making eradication difficult. The aim of this study was to develop a rabbit model of knee PJI that would allow reliable biofilm quantification and permit the study of treatments for PJI. In this work, New Zealand white rabbits ( n = 19 ) underwent knee joint arthrotomy, titanium tibial implant insertion, and inoculation with Xen36 (bioluminescent Staphylococcus aureus) or a saline control after capsule closure. Biofilm was quantified via scanning electron microscopy (SEM) of the tibial explant 14 d after inoculation ( n = 3 noninfected, n = 2 infected). Rabbits underwent debridement, antibiotics, and implant retention (DAIR) ( n = 6 ) or sham surgery ( n = 2 noninfected, n = 6 infected) 14 d after inoculation, and they were sacrificed 14 d post-treatment. Tibial explant and periprosthetic tissues were examined for infection. Laboratory assays supported bacterial infection in infected animals. No differences in weight or C-reactive protein (CRP) were detected after DAIR compared to sham treatment. Biofilm coverage was significantly decreased with DAIR treatment when compared with sham treatment (61.4 % vs. 90.1 %, p < 0 .0011) and was absent in noninfected control explants. In summary, we have developed an experimental rabbit hemiarthroplasty knee PJI model with bacterial infection that reliably produces quantifiable biofilm and provides an opportunity to introduce treatments at 14 d. This model may be used to better understand the pathogenesis of this condition and to measure treatment strategies for PJI.

Current treatments for biofilm-associated periprosthetic joint infection and new potential strategies.

Periprosthetic joint infection (PJI) remains a devastating complication after total joint arthroplasty. Bacteria involved in these infections are notorious for adhering to foreign implanted surfaces and generating a biofilm matrix. These biofilms protect the bacteria from antibiotic treatment and the immune system making eradication difficult. Current treatment strategies including debridement, antibiotics, and implant retention, and one- and two-stage revisions still present a relatively high overall failure rate. One of the main shortcomings that has been associated with this high failure rate is the lack of a robust approach to treating bacterial biofilm. Therefore, in this review, we will highlight new strategies that have the potential to combat PJI by targeting biofilm integrity, therefore giving antibiotics and the immune system access to the internal network of the biofilm structure. This combination antibiofilm/antibiotic therapy may be a new strategy for PJI treatment while promoting implant retention.

In-hospital Mortality after Septic Revision TKA: Analysis of the New York and Florida State Inpatient Databases.

The aims of this study were to investigate (1) in-hospital mortality rates following septic revision total knee arthroplasty (rTKA); (2) compare septic rTKA mortality rates between differing knee revision volume (KRV) hospitals; and (3) identify independent risk factors associated with in-hospital mortality after septic rTKA (up to 2-year follow-up). The Healthcare Cost and Utilization Project State Inpatient Databases of New York and Florida were used to identify septic rTKA, and control groups of aseptic rTKA and primary TKA between 2007 and 2012 via International Classification of Diseases, Ninth Revision codes. Mortality was compared between septic rTKA and aseptic rTKA/primary TKA control groups. Hospital KRV was stratified, and independent risk factors of in-hospital mortality were identified and analyzed using unadjusted and adjusted logistic regression analyses. In this study, 3,531 septic rTKA patients were identified; 105 (3%) patients suffered in-hospital mortality, compared with the control aseptic rTKA (n = 178; 1.7%; p < 0.0001) and primary TKA groups (n = 930; 0.6%; p < 0.0001). Being an octogenarian (adjusted odds ratio [AOR]: 2.361; 95% confidence interval [CI]: 1.514-3.683; p < 0.0002) and having a medium- or high-Elixhauser comorbidity score was associated with in-hospital mortality (AOR: 2.073; 95% CI: 1.334-3.223; p = 0.0012, and AOR: 4.127; 95% CI: 2.268-7.512, p < 0.0001). There were no significant in-hospital mortality rate differences in high- versus medium- versus low-KRV hospitals (1.9 vs. 3.6 vs. 2.9%, respectively, p = 0.0558). Age >81 years and higher comorbidity burden were found to contribute to increased risk of 2-year postoperative mortality after septic rTKA. This association could not be established for hospital KRV.