Incidence and Risk Factors for Acid-fast Bacillus/Fungal Culture Positivity in Primary, Conversion, and Revision Hip and Knee Arthroplasty.

INTRODUCTION: Previous literature has reported minimal incidences of positive fungal/AFB cultures, questioning the routine use of these tests. With growing concern for excessive use, predictive factors for patients at higher risk for intraoperative AFB/fungal infections would help surgeons limit unnecessary testing. This study evaluates the positivity rate and predictive factors of positive fungal and/or acid-fast bacillus (AFB) cultures after primary, conversion, or revision hip and knee arthroplasty. METHOD: Two hundred thirty-eight knee and hip procedures were done between January 2007 and 2022 where intraoperative AFB/fungal cultures were obtained. Procedures included primary total knee arthroplasty, primary total hip arthroplasty, conversion, first of two-stage, second of two-stage, irrigation and débridement polyexchange, and aseptic revision. Positivity rates of intraoperative AFB/fungal cultures were calculated as binomial exact proportions with 95% confidence intervals and are displayed as percentages. Univariable generalized linear mixed models estimated the unadjusted effects of demographics, individual comorbid conditions, and procedural characteristics on the logit of positive AFB/fungal cultures. RESULTS: Two hundred thirty-eight knee and hip procedures recorded an overall positivity rate of 5.8% for intraoperative AFB/fungal cultures. Aseptic revisions showed the lowest rates of positivity at 3.6%, while conversions showed the highest rates of positivity at 14.3%. The positivity rates are highest among patients who are male (9.0%), of Hispanic origin (12.0%), with body mass index <30 (6.4%), and a Charlson Comorbidity Index <5 (6.1%). History of a prior infection in the same surgical joint showed statistically significant influence of odds of culture positivity with an odds ratio of 3.47 ( P -value: 0.039). Other demographic factors that we investigated including age, sex, race, ethnicity, body mass index, and Charlson Comorbidity Index did not show any notable influence on AFB/fungal positivity rates. CONCLUSION: These results suggest utility in obtaining routine intraoperative AFB/fungal cultures, given the relatively high positivity and poor predictive factors.

Total Joint Arthroplasty in Patients With Lymphedema as Compared to a Propensity-Matched Control Cohort.

Background: Lymphedema is rare in arthroplasty patients but has been associated with a higher complication rate. This study sought to determine the outcomes of total joint arthroplasty in patients with lymphedema as compared to a matched control cohort. Methods: Treatment-control propensity matching was implemented on 335 patients following total knee or hip arthroplasty generating 5-patient sets of one patient with presurgery lymphedema (67 total) to 4 patients without presurgery lymphedema (268 total) and matched on age, sex, and surgery year. Body mass index and presence of diabetes were controlled using multivariable generalized estimating equations. Results: In the lymphedema cohort, 1 patient (1.5%) had a deep vein thrombosis within 90 days of their surgery, 36 (53.7%) were discharged to a rehabilitation center, 16 (23.9%) had a readmission, 14 (20.9%) were admitted to the emergency room within 90 days, 6 (9.0%) experienced infection, and 6 (9.0%) had a revision/reoperation. Lymphedema significantly increased emergency room admission within 90 days (odds ratio [OR] 4.56, P = .01) and non-home discharge (OR 4.14, P < .01), affected readmission within 90 days (OR 2.21, P = .09), revision/reoperation (OR 2.82, P = .09), and no effect on deep vein thrombosis within 90 days (OR 0.57, P = .45), postsurgical infection (OR 1.47, P = .45), length of stay (OR 0.00, P = .99), operative time (OR 0.04, P = .38), or estimated blood loss (OR 0.09, P = .47), after adjusting for various factors. Conclusions: Preoperative lymphedema is a significant risk factor for patients who are undergoing total joint arthroplasty. Preoperative and postoperative modalities should be utilized to help control lymphedema and mitigate these increased risks.

Prevention Techniques Have Had Minimal Impact on the Population Rate of Prosthetic Joint Infection for Primary Total Hip and Knee Arthroplasty: A National Database Study.

BACKGROUND: Several studies over the years have offered modalities that may greatly decrease the rate of periprosthetic joint infection when implemented. As a result, one would expect a drastic decrease in infection rate among the implementing population with its widespread use. The purpose of this study was to assess whether there exists a decrease in infection rate over time, after accounting for available confounding variables, within a large national database. METHODS: A large national database from 2005 to 2019 was queried for primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). In total, 221,416 THAs and 354,049 TKAs were performed over the study period. Differences in 30-day infection rate were assessed with time and available preoperative risk factors using multinominal logistic regressions. RESULTS: Rate of infection overall trended downward for both THA and TKA. After accounting for confounding variables, odds of THA infection marginally decreased over time (odds ratio 0.968 [0.952-0.985], P < .0001), while the odds of a TKA infection marginally increased with time (odds ratio 1.037 [1.020-1.054], P < .0001). CONCLUSION: Individual peer-reviewed publications have presented infection control modalities demonstrating dramatic decreases in infection rate while analysis at a population level shows almost no changes in infection rate over a 15-year time period. This study supports continued investigation for influential modalities in preventing periprosthetic joint infection and care in patient selection for primary hip and knee arthroplasty.

Artificial Intelligence Autonomously Measures Cup Orientation, Corrects for Pelvis Orientation, and Identifies Retroversion From Antero-Posterior Pelvis Radiographs.

BACKGROUND: Measuring cup orientation is time consuming and inaccurate, but orientation influences the risk of impingement and dislocation following total hip arthroplasty (THA). This study designed an artificial intelligence (AI) program to autonomously determine cup orientation, correct for pelvis orientation, and identify cup retroversion from an antero-posterior pelvic radiographs. METHODS: There were 2,945 patients between 2012 and 2019 identified to have 504 computed tomographic (CT) scans of their THA. A 3-dimensional (3D) reconstruction was performed on all CTs, where cup orientation was measured relative to the anterior pelvic plane. Patients were randomly allocated to training (4,000 x-rays), validation (511 x-rays), and testing (690 x-rays) groups. Data augmentation was applied to the training set (n = 4,000,000) to increase model robustness. Statistical analyses were performed only on the test group in their accuracy with CT measurements. RESULTS: AI predictions averaged 0.22 ± 0.03 seconds to run on a given radiograph. Pearson correlation coefficient was 0.976 and 0.984 for AI measurements with CT, while hand measurements were 0.650 and 0.687 for anteversion and inclination, respectively. The AI measurements more closely represented CT scans when compared to hand measurements (P < .001). Measurements averaged 0.04 ± 2.21°, 0.14 ± 1.66°, -0.31 ± 8.35°, and 6.48° ± 7.43° from CT measurements for AI anteversion, AI inclination, hand anteversion, and hand inclination, respectively. AI predictions identified 17 radiographs as retroverted with 100.0% accuracy (total retroverted, n = 45). CONCLUSION: The AI algorithms may correct for pelvis orientation when measuring cup orientation on radiographs, outperform hand measurements, and may be implemented in a timely fashion. This is the first method to identify a retroverted cup from a single AP radiograph.

Development of the Illinois Surgical Quality Improvement Collaborative (ISQIC): Implementing 21 Components to Catalyze Statewide Improvement in Surgical Care.

INTRODUCTION: In 2014, 56 Illinois hospitals came together to form a unique learning collaborative, the Illinois Surgical Quality Improvement Collaborative (ISQIC). Our objectives are to provide an overview of the first three years of ISQIC focused on (1) how the collaborative was formed and funded, (2) the 21 strategies implemented to support quality improvement (QI), (3) collaborative sustainment, and (4) how the collaborative acts as a platform for innovative QI research. METHODS: ISQIC includes 21 components to facilitate QI that target the hospital, the surgical QI team, and the peri-operative microsystem. The components were developed from available evidence, a detailed needs assessment of the hospitals, reviewing experiences from prior surgical and non-surgical QI Collaboratives, and interviews with QI experts. The components comprise 5 domains: guided implementation (e.g., mentors, coaches, statewide QI projects), education (e.g., process improvement (PI) curriculum), hospital- and surgeon-level comparative performance reports (e.g., process, outcomes, costs), networking (e.g., forums to share QI experiences and best practices), and funding (e.g., for the overall program, pilot grants, and bonus payments for improvement). RESULTS: Through implementation of the 21 novel ISQIC components, hospitals were equipped to use their data to successfully implement QI initiatives and improve care. Formal (QI/PI) training, mentoring, and coaching were undertaken by the hospitals as they worked to implement solutions. Hospitals received funding for the program and were able to work together on statewide quality initiatives. Lessons learned at one hospital were shared with all participating hospitals through conferences, webinars, and toolkits to facilitate learning from each other with a common goal of making care better and safer for the surgical patient in Illinois. Over the first three years, surgical outcomes improved in Illinois. DISCUSSION: The first three years of ISQIC improved care for surgical patients across Illinois and allowed hospitals to see the value of participating in a surgical QI learning collaborative without having to make the initial financial investment themselves. Given the strong support and buy-in from the hospitals, ISQIC has continued beyond the initial three years and continues to support QI across Illinois hospitals.

Outcomes of Total Knee and Hip Arthroplasty in Patients With Perioperative Thrombocytopenia.

BACKGROUND: Thrombocytopenia is an abnormally low level of blood platelets (less than 150,000/mL) resulting in an increased risk for bleeding. Typically, patients with platelet levels below 50,000/mL should delay arthroplasty or be transfused with platelets before surgery. However, existing studies are mixed regarding the effects of more moderate thrombocytopenia in terms of total knee and hip arthroplasty outcomes. METHODS: This level III retrospective chart review examined the effects of different severities of preoperative thrombocytopenia on length of hospitalization, readmission, and transfusion rates in 5,617 primary total knee and hip arthroplasties at one tertiary academic medical center. Preoperative platelet levels were sectioned into clinically relevant groups and compared with clinical outcomes using univariable and multivariable models. RESULTS: On univariate analysis, having platelet levels of <100,000/mL and 100 to 149,000/mL was associated with a longer length of stay. However, after controlling individual demographics, there was no association between platelet levels and length of stay, nor with 30-day readmission. Finally, on univariate analysis, patients with platelet levels of <100,000/mL and 100 to 149,000/mL were more likely to have a blood transfusion, which remained true for those with <100,000/mL after controlling for individual demographics. CONCLUSIONS: Total hip and total knee arthroplasty are safe in patients with varying platelet levels and not associated with increased length of stay or 30-day readmission. However, patients with more severe thrombocytopenia are more likely to receive red blood cell transfusions than patients with milder thrombocytopenia.

Predictors of Success With Chronic Antibiotic Suppression for Prosthetic Joint Infections.

BACKGROUND: Management of recurrent prosthetic joint infection (PJI) after attempted surgical eradication remains a challenge. Chronic antibiotic suppression (CAS) is regarded as a reasonable treatment option for select patients with persistent infection or multiple comorbidities. The study seeks to compare cohorts who succeed and fail with CAS. METHODS: This retrospective cohort study assesses patients who were treated with CAS for a PJI. Patients were included if they had a culture-proven PJI and received chronic suppressive antibiotics. Failure of suppression was defined as reoperation after initiating CAS or death occurring as result of infection. A Cox proportional hazards multivariate regression model was used to estimate risk of reoperation as a function of risk factors related to patient comorbidities, surgical history, affected joint, and infecting organism. RESULTS: We identified 45 PJIs (31 knees, 14 hips) managed with CAS with a median follow-up of 50 (95% confidence interval [CI] 33.61-74.02) months. The overall success rate of managing PJI with CAS was 67% (30/45). Controlling for body mass index and Gram status of the organism, total hip arthroplasty patients were less likely than total knee arthroplasty patients to require reoperation (hazard ratio 0.18, 95% CI 0.01-0.96, P = .04). Patients with Gram-positive infections were less likely than those with a Gram-negative infections to require reoperation (hazard ratio 0.22, 95% CI 0.05-0.88, P = .03). Severe antibiotic side effects were rare. Patients who experienced multiple changes to their antibiotic regimen were more likely to fail with CAS. CONCLUSION: CAS is a reasonable strategy in patients with PJI who lack or refuse further surgical treatment options. Most hips and Gram-positive infections treated with CAS successfully avoided reoperation in this cohort.

New Primary Total Knee Arthroplasty Components Versus Other Contemporary Types of Spacers for the Treatment of Chronic Periprosthetic Knee Infection With a Two-Stage Protocol.

The optimal type of antibiotic spacer for the treatment of a knee periprosthetic joint infection (PJI) remains a topic of debate. Although the ultimate goal of an antibiotic spacer is infection control, contemporary spacer iterations, such as the use of a new femoral component (NFC), may offer unique advantages. The primary goal of this study was to compare rates of infection control and functional outcomes between contemporary spacer types. We retrospectively reviewed 96 patients who underwent removal of a total knee arthroplasty with insertion of an antibiotic spacer for knee PJI over a 14-year period at a single institution with a minimum 1-year follow-up. Three patient cohorts were defined based on spacer type: NFC (n=30), cement-on-cement (n=19), and static (n=47). There was no association between spacer type and the odds of infection clearance (P=.60). The NFC spacers resulted in increased knee range of motion before replantation and improved ambulatory status at 8 weeks postre-plantation, although no difference was seen at final follow-up. The use of NFC spacers may provide functional advantages over their contemporary counterparts, and the potential of NFC spacers to be used in single-stage exchange arthroplasty remains an appealing area of investigation. Future high-powered, prospective, noninferiority studies between contemporary spacer types are needed. [Orthopedics. 2022;45(2):109-115.].

Nonoperative Treatment of a Fractured Uncemented Extensively Coated Femoral Stem: A Case Report with 2-Year Follow-up.

CASE: A 62-year-old man who underwent total hip arthroplasty (THA) 17 years earlier presented with a fractured uncemented extensively coated diaphyseal engaging femoral stem. Treatment options, including revision surgery, were discussed, and the patient elected for nonoperative treatment. At 2 years of follow-up, the patient is asymptomatic, radiographs are stable, and he lives an active lifestyle without restrictions. CONCLUSION: Fractures of well-fixed femoral prostheses are rare complications of THA and almost universally require revision surgery. Nonoperative treatment without activity restrictions may be a viable treatment option in select patients to preserve function and maintain quality of life.

Regulation of Cortisol in Patients Undergoing Total Joint Arthoplasty.

Osteoarthritis is a condition in which joint cartilage and bone degenerate progressively over time. Total joint arthroplasty is a definitive treatment. Cortisol is a hormone that is associated with pain and inflammation. This study aims to investigate the cortisol levels in patients undergoing total joint arthroplasty. Plasma samples were collected from 71 total joint arthroplasty (TJA) patients at baseline (pre-surgery), 24 hours post-operation, and 5 days post-operation. Cortisol levels were measured in each sample using a commercially available ELISA kit. All results were compiled as group means ± SD. The plasma cortisol level at baseline were 218.5 ± 12 ng/mL. The 24-hour post-surgical samples showed a marked increase in cortisol levels 240.7 ± 15 ng/mL. The blood samples drawn at the 5th day after surgery showed a downward trend (74 ± 12 ng/mL). At 5 days post-operation, cortisol levels were significantly lower than at baseline or 24 hours post-operation. These results point to the fact that prior to surgery, the patient's emotional stress contributes to increased serum cortisol levels. The higher level of cortisol persists at 24 hours post-operation due to inflammation from the procedure. This data also suggests that at 5 days post-operation, the inflammatory response from the surgery and emotional stress subside, resulting in a near normalization of the cortisol levels. Cortisol is a hormone that plays a major role in the body's response to surgery. The relevance between cortisol and different points in the surgical timeline has the potential to prognosticate and improve recovery measures.

Interrelationship of MMP-9, Proteoglycan-4, and Inflammation in Osteoarthritis Patients Undergoing Total Hip Arthroplasty.

Osteoarthritis (OA) is a chronic condition marked by joint pain, inflammation and loss of articular cartilage, that can be treated with total joint arthroplasty (TJA) at end stages. TJA is marked by post-operative inflammation, which directly effects levels of cartilage degradation biomarkers, proteoglycan-4 (PRG4) and matrix metalloproteinase-9 (MMP-9). PRG4 is a protective glycoprotein that is decreased in individuals with OA. MMP-9 is a matrix metalloproteinase that contributes to articular cartilage loss and is elevated in OA patients. It is upregulated by pro-inflammatory markers, such as IL-1, IL-6 and CRP. This study aims to elucidate the immediate post-operative changes in levels of PRG4, MMP-9, IL-6, CRP, and WBC in patients undergoing TJA to clarify the role of inflammation in recovery after surgery and in the overall pathogenesis of OA. Blood was collected at 3 time points (day 0, day 1 post-operatively, and days 5-7 post-operatively), from 63 patients undergoing TJA due to OA, and levels of these biomarkers were quantified. IL-6, CRP, WBC and MMP-9 were lowest at day 0, highest at day 1, and stabilized at an intermediate level at days 5-7. Meanwhile, PRG4 followed the opposite trend. These studies suggest that IL-6, CRP and WBC showed predictable fluctuations, with pro-inflammatory biomarkers upregulating MMP-9 and downregulating PRG4. Measuring these biomarkers may help expose the role of inflammation in the post-surgical recovery of TJA patients and in long-term pathogenesis of OA. These levels may help risk stratify patients pre-operatively and help develop individualized post-surgical plans.

Interrelationship of Osteopontin, MMP-9 and ADAMTS4 in Patients With Osteoarthritis Undergoing Total Joint Arthroplasty.

Osteoarthritis (OA) is a degenerative joint disease characterized by loss of articular cartilage, inflammation and pain, which sometimes necessitates total joint arthroplasty (TJA). Profiling biomarkers of cartilage degradation and inflammation is a promising area of research to understand the pathogenesis of OA. This study aims to report the post-operative fluctuations of 3 biomarkers of OA, osteopontin (OPN), matrix metalloproteinase-9 (MMP-9), and ADAMTS4 (a disintegrin and metalloproteinase with thrombospondin motifs 4), in patients undergoing TJA to further define the interaction among these biomarkers and delineate their role in OA pathogenesis. OPN is an extracellular matrix (ECM) glycoprotein with increased activity in OA and joint damage and is upregulated by either inflammation or cleavage by MMPs and thrombin. MMP-9 is known to cleave OPN and is upregulated by inflammatory markers, such as IL-1, IL-6 and CRP. ADAMTS4 is an enzyme that degrades aggrecan, a major component of cartilage. These biomarkers were measured in deidentified blood samples collected on the day of surgery, 1 day post-operatively, and day 5-7 post-operatively. MMP-9 and OPN levels were significantly elevated at all times, and ADAMTS4 was significantly decreased at baseline versus controls. OPN and ADAMTS4 inversely fluctuated post-operatively, indicating an interrelation between these 2 biomarkers. This study suggests that the upregulation of MMP-9 and therefore OPN then results in the downregulation of ADAMTS4. The relationship between OPN and thrombin also highlights the importance of monitoring for thrombotic complications. These biomarkers, along with thrombin-mediated cleavage products, may be helpful in the prognostic management of OA patients.

Demographic data is more predictive of component size than digital radiographic templating in total knee arthroplasty.

BACKGROUND: Preoperative radiographic templating for total knee arthroplasty (TKA) has been shown to be inaccurate. Patient demographic data, such as gender, height, weight, age, and race, may be more predictive of implanted component size in TKA. MATERIALS AND METHODS: A multivariate linear regression model was designed to predict implanted femoral and tibial component size using demographic data along a consecutive series of 201 patients undergoing index TKA. Traditional, two-dimensional, radiographic templating was compared to demographic-based regression predictions on a prospective 181 consecutive patients undergoing index TKA in their ability to accurately predict intraoperative implanted sizes. Surgeons were blinded of any predictions. RESULTS: Patient gender, height, weight, age, and ethnicity/race were predictive of implanted TKA component size. The regression model more accurately predicted implanted component size compared to radiographically templated sizes for both the femoral (P = 0.04) and tibial (P < 0.01) components. The regression model exactly predicted femoral and tibial component sizes in 43.7 and 43.7% of cases, was within one size 90.1 and 95.6% of the time, and was within two sizes in every case. Radiographic templating exactly predicted 35.4 and 36.5% of cases, was within one size 86.2 and 85.1% of the time, and varied up to four sizes for both the femoral and tibial components. The regression model averaged within 0.66 and 0.61 sizes, versus 0.81 and 0.81 sizes for radiographic templating for femoral and tibial components. CONCLUSIONS: A demographic-based regression model was created based on patient-specific demographic data to predict femoral and tibial TKA component sizes. In a prospective patient series, the regression model more accurately and precisely predicted implanted component sizes compared to radiographic templating. LEVEL OF EVIDENCE: Prospective cohort, level II.

Minimum twelve-year follow-up of fixed- vs mobile-bearing total knee arthroplasty: Double blinded randomized trial.

BACKGROUND: Total knee arthroplasty (TKA) with fixed-bearing (FB) implants have demonstrated impressive functional results and survival rates. Meanwhile, rotating-platform (RP) constructs have biomechanically shown to reduce polyethylene wear, lower the risk of component loosening, and better replicate anatomic knee motion. There is growing question of the clinical impact these design changes have long-term.Questions/purposes: The aim of this double-blinded prospective randomized trial was to compare function and implant survival in patients who received either FB or RP press-fit condylar Sigma (PFC Sigma, DePuy, Warsaw, IN) total knee replacements at a minimum follow-up of twelve years. PATIENTS AND METHODS: Patient reported outcome measures used included the functional Knee Society Score, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores, Medical Outcomes Short Form-36 (SF-36) score, and satisfaction assessment on a four-point Likert scale. The data was collected from times preoperative, two-years, and final encounter (mean 13.95 years). A total of 28 RP and 19 FB knees (58.8%) were analyzed at the final follow-up. RESULTS: Among all patients, KSS and WOMAC scores statistically improved from pre-op to 2-year, while KSS statistically worsened from 2-year to final follow-up. The RP group averaged better follow-up scores in all assessments at the final follow-up with exception of overall satisfaction. There was no statistically significant difference in the functional Knee Society Score, Short Form-36, WOMAC scores, patient satisfaction or implant survival between the two groups at any measured period. CONCLUSIONS: The use of a fixed-bearing or rotating-platform design does not convey significant superiority in terms of function or implant longevity at a minimum twelve years after total knee arthroplasty. LEVEL OF EVIDENCE: Level I, Experimental study, randomized controlled trial (RCT).

A precise method for determining acetabular component anteversion after total hip arthroplasty.

AIMS: Several radiological methods of measuring anteversion of the acetabular component after total hip arthroplasty (THA) have been described. These are limited by low reproducibility, are less accurate than CT 3D reconstruction, and are cumbersome to use. These methods also partly rely on the identification of obscured radiological borders of the component. We propose two novel methods, the Area and Orthogonal methods, which have been designed to maximize use of readily identifiable points while maintaining the same trigonometric principles. PATIENTS AND METHODS: A retrospective study of plain radiographs was conducted on 160 hips of 141 patients who had undergone primary THA. We compared the reliability and accuracy of the Area and Orthogonal methods with two of the current leading methods: those of Widmer and Lewinnek, respectively. RESULTS: The 160 anteroposterior pelvis films revealed that the proposed Area method was statistically different from those described by Widmer and Lewinnek (p < 0.001 and p = 0.004, respectively). They gave the highest inter- and intraobserver reliability (0.992 and 0.998, respectively), and took less time (27.50 seconds (sd 3.19); p < 0.001) to complete. In addition, 21 available CT 3D reconstructions revealed the Area method achieved the highest Pearson's correlation coefficient (r = 0.956; p < 0.001) and least statistical difference (p = 0.704) from CT with a mean within 1° of CT-3D reconstruction between ranges of 1° to 30° of measured radiological anteversion. CONCLUSION: Our results support the proposed Area method to be the most reliable, accurate, and speedy. They did not support any statistical superiority of the proposed Orthogonal method to that of the Widmer or Lewinnek method. Cite this article: Bone Joint J 2019;101-B:1042-1049.

Matrix Metalloproteinases and Their Inhibitors and Proteoglycan 4 in Patients Undergoing Total Joint Arthroplasty.

Osteoarthritis, a degenerative disease of the joints, is the most common form of arthritis in the knee. Total joint arthoplasty is a commonly used treatment for joint degeneration and osteoarthritis, and due to these factors, TJA for hip and knee joints is projected to grow by 137% and 601% between 2005 and 2030. Matrix metalloproteases are enzymes found in the extracellular matrix that cleave matrix components. Normally MMPs are downregulated in tissues by Tissue Inhibitors of Metalloproteases, or TIMPs. The relative concentration of TIMPs also may denote some of the activity of the MMPs found in serum. Lubricin (proteoglycan 4) is a molecule found in the synovial fluid that protects joints by dissipating strain energy during locomotion. Lubricin synovial fluid concentration is also diminished in many patients with osteoarthritis, but not all. Given the importance of these three sets of molecules, our lab investigated the correlation between circulating lubricin, MMP levels and TIMPs levels. Blood plasma samples were obtained from de-identified subjects undergoing total joint arthroplasty at Loyola University Medical Center and the University of Utah. Normal blood plasma from pooled healthy individuals served as a control. We analyzed biomarker levels in plasma using ELISA. Our data show that MMP-1 and 9 were increased in TJA patients compared to normal controls, while MMP-2 and 13 were decreased. We also found decreased lubricin and tissue factor in surgical patients relative to controls. These data support the idea that lubricin is vital in protecting the synovial joint and that MMPs play a complex role in the destruction of the joint.

Cognitive Skills Assessment for the Aging Orthopaedic Surgeon: AOA Critical Issues.

Physician leaders are increasingly confronted with the challenge of evaluating the performance of surgical colleagues during the last phase of their careers. Identification of physicians with declining cognitive and clinical skills must be balanced against awareness of laws protecting colleagues from discrimination. Responding successfully to this challenge requires appropriate policies, reliable data, standardized evaluation tools, consistent documentation, and the development of compassionate and effective solutions that avoid discriminatory practices. Surgical champions are essential for promoting self-regulation. Performance evaluations should comply with medical staff bylaws and institutional wellness policies.

Total hip arthroplasty and femoral nail lengthening for hip dysplasia and limb-length discrepancy.

The application of distraction osteogenesis through the use of magnet-operated, remote-controlled intramedullary lengthening continues to provide new opportunities for accurate limb equalization. While limb-length discrepancy and deformity can be addressed by total hip arthroplasty alone, the magnitude of correction is limited by the soft-tissue envelope and complications such as sciatic nerve palsy. This 3-patient case series presents the combination of staged ipsilateral total hip arthroplasty and retrograde intramedullary femoral nail lengthening for the correction of both deformity and limb-length discrepancy. Our results report leg-length equalization, independent ambulation without assistive devices, and excellent bone and functional outcomes without complications, demonstrating that this combined technique can be used to achieve targeted lengthening and deformity correction.

Inflammatory Biomarker Profiling in Total Joint Arthroplasty and Its Relevance to Circulating Levels of Lubricin, a Novel Proteoglycan.

Lubricin, also known as proteoglycan 4, acts as an antiadhesive and boundary lubricant to prevent cartilage damage in healthy joints. Following injury, a decrease in synovial fluid (SF) lubricin may lead to secondary osteoarthritis (OA). Inflammatory biomarkers, such as IL-1ß and TNF-α, are also implicated in the pathophysiology of OA. Interestingly, they have been shown to suppress the expression and secretion of lubricin in SF. This study aims to compare circulating levels of inflammatory biomarkers and lubricin between total joint arthroplasty (TJA) patients and healthy individuals. Doing so may better elucidate their roles in OA and extend the understanding of inflammation as a regulator of lubricin. Deidentified plasma samples were obtained 1 day preoperatively and 1 day postoperatively from patients undergoing TJA. Utilizing biochip array technology, they were profiled for IL-2, IL-4, IL-6, IL-8, IL-10, VEGF, IFN-γ, IL-1α, IL-1ß, MCP-1, EGF, and TNF-α. Circulating lubricin levels were also measured using enzyme-linked immunosorbent assay. Compared to healthy controls, IL-6, IL-8, VEGF, IL-1ß, MCP-1, EGF, and TNF-α were significantly increased pre- and postoperatively. Lubricin was significantly decreased. This may indicate that elevations in inflammatory cytokines initiate a cascade of events, leading to decreased lubricin, which places the joint at increased risk of developing OA.

Postoperative Changes in the Systemic Inflammatory Milieu in Older Surgical Patients.

Dysregulated inflammation is a central component of wound healing following surgery. We prospectively enrolled older patients (n = 25, age 65 ± 7 years) undergoing elective total knee arthroplasty or total hip arthroplasty secondary to advanced osteoarthritis (OA) and healthy controls (n = 48). Inflammatory, proangiogenic (vascular endothelial growth factor [VEGF], monocyte chemoattractant protein-1 [MCP-1], and interleukin-8 [IL-8]), and antiangiogenic (interferon γ [IFN-γ] and IL-4) factors were measured using a high-sensitivity biochip. Patients with OA had significantly higher baseline VEGF (10.5 ± 1.2 pg/mL vs 4.8 ± 0.2 pg/mL, P < .001), MCP-1 (130.6 ± 7.7 pg/mL vs 88.6 ± 3.9 pg/mL, P < .0001), and IL-8 (4.0 ± 0.5 pg/mL vs 2.6 ± 0.1 pg/mL, P < .05). Postoperatively, the levels of VEGF (10.5 ± 1.2 pg/mL vs 18.8 ± 1.5 pg/mL, P < .001) and MCP-1 (130.6 ± 7.7 pg/mL vs 153.1 ± 11.5 pg/mL, P < .05) increased significantly. Baseline and postoperative MCP-1 levels correlated positively and significantly with age. The levels of IFN-γ and IL-4 (which has anti-inflammatory properties) did not significantly differ at baseline in patients with OA compared to controls and did not significantly rise postoperatively. We conclude that systemic levels of pro-inflammatory and angiogenic proteins are increased in patients with OA and rise further postoperatively, while proteins that restrain inflammation and angiogenesis do not coordinately rise. These findings implicate imbalance in inflammatory pathways in OA that may contribute to its pathobiology.