Faculty Bibliography

INTRODUCTION/BACKGROUND:Prosthetic joint infection continues to be a source of significant morbidity to patients and an economic burden to society as a whole. Two-stage revision is the current gold standard for treatment of periprosthetic joint infection in North America. Despite this, much discussion persists about treatment strategies surrounding the interim of the two-stage revision and treatment beyond reimplantation. The aim of this review is to answer some of these questions, specifically: are C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) helpful prior to reimplantation, is aspiration helpful, what is the role and timing for systemic antibiotics, and is there a role for oral suppression following second-stage reimplantation? METHODS:A literature review was completed in an attempt to address unanswered questions associated with two-stage reimplantation. Investigators' recommendations and current practices are described. RESULTS:ESR and CRP are less reliable in the interim of a two-stage revision than for diagnosis of infection in a primary total joint arthroplasty. There is inconclusive evidence regarding the utility of joint aspiration in two-stage revisions. Additionally, no evidence has been developed for length of IV antibiotic treatment after second-stage reimplantation, and in a few studies, oral antibiotic suppression has shown some benefit in reducing reinfection rates. CONCLUSION/CONCLUSIONS:The question of optimum treatment strategies has yet to be answered: attempts are underway to obtain suitable data with multi-center studies and large patient populations. Periprosthetic joint infection is a serious and life altering complication and with continued research we can further clarify treatment strategies.

Postoperative radiographs remain the standard for assessment of component placement following total hip arthroplasty (THA), despite the known limitations of radiographs. Computed tomography (CT) scanning offers improved accuracy, but its costs and radiation exposure are prohibitive. The authors performed a cadaver study to compare the error associated with radiographs with that of CT scans following THA. The authors also compared imaging with a novel mini-navigation system. Three board-certified orthopedic surgeons each performed 4 THA procedures (6 cadavers, 12 hips) via the posterior approach using a mini-navigation tool to assist with component placement. Cup position from imaging was compared with corrected CT values for anteversion and inclination, created by correcting the initial scan to align the anterior pelvic plane coplanar with the CT table, thus representing cup position not distorted by imaging or positioning. Anteversion from standard CT scans was within 2.5° (standard deviation [SD], 1.5°) of reference values (P=.25); radiographs showed an average error of 7.8° (SD, 4.3°) vs reference values (all values absolute means) (P<.01). The mini-navigation system provided anteversion values within an average of 4.0° (SD, 4.0°) of reference anteversion (P<.01). Standard CT values for inclination were within 2.4° (SD, 2.0°) of reference values (P=.53), whereas radiographic inclination values were within 2.5° (SD, 2.3°) (P=.12). Mini-navigation values for inclination were within 3.9° (SD, 3.2°) of reference inclination (P=.26). This study demonstrated that cup position as measured by radiographs is significantly less accurate than CT scans and that the mini-navigation system provided anteversion measurements that were of comparable accuracy to CT scans. [Orthopedics. 2017; 40(6):e952-e958.].

BACKGROUND: Accurate cup positioning is one of the most challenging aspects of total hip arthroplasty (THA). Undetected movement of the patient during THA surgery can lead to inaccuracies in cup anteversion and inclination, increasing the potential for dislocation and revision surgery. Investigations into the magnitude of patient motion during THA are not well represented in the literature. METHODS: We analyzed intraoperative pelvic motion using a novel navigation device used to assist surgeons with cup position, leg length, and offset during THA. This device uses an integrated accelerometer to measure motion in 2 orthogonal degrees of freedom. We reviewed the data from 99 cases completed between February and September 2016. RESULTS: The mean amount of pitch recorded per patient was 2.7 degrees (standard deviation, 2.2; range, 0.1 degrees -9.9 degrees ), whereas mean roll per patient was 7.3 degrees (standard deviation, 5.5; range, 0.3 degrees -31.3 degrees ). Twenty-one percent (21 of 99) of patients demonstrated pitch of >4 degrees . Sixty-nine percent (68 of 99) of patients demonstrated >4 degrees of roll, and 25% (25 of 99) of patients demonstrated roll of >/=10 degrees . CONCLUSION: Our findings indicate that while the majority of intraoperative motion is <4 degrees , many patients experience significant roll, with a large proportion rolling >10 degrees . This degree of movement has implications for acetabular cup position, as failure to compensate for this motion can result in placement of the cup outside the planned safe zone, thus, increasing the potential for dislocation. Further study is warranted to determine the effect of this motion on cup position, leg length, and offset.

Background/UNASSIGNED:As medical management continues to improve, orthopaedic surgeons are likely to encounter a greater proportion of patients who have coinfection with human immunodeficiency virus (HIV) and hepatitis-C virus (HCV). Methods/UNASSIGNED:The New York Statewide Planning and Research Cooperative System (SPARCS) database was used to identify patients undergoing total knee arthroplasty between 2010 and 2014. Patients were stratified into 4 groups on the basis of HCV and HIV status. Differences regarding baseline demographics, length of stay, total charges, discharge disposition, in-hospital complications and mortality, and 90-day hospital readmission were calculated. Results/UNASSIGNED:Between 2010 and 2014, a total of 137,801 patients underwent total knee arthroplasty. Of those, 99.13% (136,604) of the population were not infected, 0.62% (851) had HCV monoinfection, 0.20% (278) had HIV monoinfection, and 0.05% (68) were coinfected with both HCV and HIV. Coinfected patients were more likely to be younger, female, a member of a minority group, homeless, and insured by Medicare or Medicaid, and to have a history of substance abuse. HCV and HIV coinfection was a significant independent risk factor for increased length of hospital stay (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.75 to 4.81), total hospital charges in the 90th percentile (OR, 2.02; 95% CI, 1.12 to 3.67), ≥2 in-hospital complications (OR, 2.04; 95% CI, 1.04 to 3.97), and 90-day hospital readmission (OR, 3.53; 95% CI, 2.02 to 6.18). Conclusions/UNASSIGNED:Patients coinfected with both HCV and HIV represent a rare but increasing population of individuals undergoing total knee arthroplasty. Recognition of unique baseline demographics in these patients that may lead to suboptimal outcomes will allow appropriate preoperative management and multidisciplinary coordination to reduce morbidity and mortality while containing costs. Level of Evidence/UNASSIGNED:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Declining total joint arthroplasty reimbursement and rising implant prices have led many hospitals to restrict access to newer, more expensive total joint arthroplasty implants. The authors sought to understand arthroplasty surgeons' perspectives on implants regarding innovation, product launch, costs, and cost-containment strategies including surgeon gain-sharing and patient cost-sharing. Members of the International Congress for Joint Reconstruction were surveyed regarding attitudes about implant technology and costs. Descriptive and univariate analyses were performed. A total of 126 surgeons responded from all 5 regions of the United States. Although 76.9% believed new products advance technology in orthopedics, most (66.7%) supported informing patients that new implants lack long-term clinical data and restricting new implants to a small number of investigators prior to widespread market launch. The survey revealed that 66.7% would forgo gain-sharing incentives in exchange for more freedom to choose implants. Further, 76.9% believed that patients should be allowed to pay incremental costs for "premium" implants. Surgeons who believed that premium products advance orthopedic technology were more willing to forgo gain-sharing (P=.040). Surgeons with higher surgical volume (P=.007), those who believed implant companies should be allowed to charge more for new technology (P<.001), and those who supported discussing costs with patients (P=.004) were more supportive of patient cost-sharing. Most arthroplasty surgeons believe technological innovation advances the field but support discussing the "unproven" nature of new implants with patients. Many surgeons support alternative payment models permitting surgeons and patients to retain implant selection autonomy. Most respondents prioritized patient beneficence and surgeon autonomy above personal financial gain. [Orthopedics. 2017; 40(5):e825-e830.].

BACKGROUND: Significant attempts have been made to adopt practices to minimize blood transfusion after total joint arthroplasty (TJA) because of transfusion cost and potential negative clinical consequences including allergic reactions, transfusion-related lung injuries, and immunomodulatory effects. We aimed to evaluate risk factors for blood transfusion in a large cohort of TJA patients. METHODS: We used the all-payer California Healthcare Cost and Utilization Project data from 2006 to 2011 to examine the trends in utilization of blood transfusion among arthroplasty patients (n = 320,746). We performed descriptive analyses and multivariate logistic regression clustered by hospital, controlling for Deyo-Charlson comorbidity index, age, insurance type (Medicaid vs others), gender, procedure year, and race/ethnicity. RESULTS: Eighteen percent (n = 59,038) of TJA patients underwent blood transfusion during their surgery, from 15% with single knee to 45% for bilateral hip arthroplasty. Multivariate analysis indicated that compared with the referent category of single knee arthroplasty, single hip had a significantly higher odds of blood transfusion (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.68-1.83), as did bilateral knee (OR, 3.57; 95% CI, 3.20-3.98) and bilateral hip arthroplasty (OR, 6.17; 95% CI, 4.85-7.85). Increasing age (eg, age >/=80 years; OR, 2.99; 95% CI, 2.82-3.17), Medicaid insurance (OR, 1.36; 95% CI, 1.27-1.45), higher comorbidity index (eg, score of >/=3; OR, 2.33; 95% CI, 2.22-2.45), and females (OR, 1.75; 95% CI, 1.70-1.80) all had significantly higher odds of blood transfusion after TJA. CONCLUSION: Primary hip arthroplasties have significantly greater risk of transfusion than knee arthroplasties, and bilateral procedures have even greater risk, especially for hips. These factors should be considered when evaluating the risk for blood transfusions.

BACKGROUND: Although HbA1c is commonly used for assessing glycemic control before surgery, there is no consensus regarding its role and the appropriate threshold in predicting adverse outcomes. This study was designed to evaluate the potential link between HbA1c and subsequent periprosthetic joint infection (PJI), with the intention of determining the optimal threshold for HbA1c. METHODS: This is a multicenter retrospective study, which identified 1645 diabetic patients who underwent primary total joint arthroplasty (1004 knees and 641 hips) between 2001 and 2015. All patients had an HbA1c measured within 3 months of surgery. The primary outcome of interest was a PJI at 1 year based on the Musculoskeletal Infection Society criteria. Secondary outcomes included orthopedic (wound and mechanical complications) and nonorthopedic complications (sepsis, thromboembolism, genitourinary, and cardiovascular complications). A regression analysis was performed to determine the independent influence of HbA1c for predicting PJI. RESULTS: Overall 22 cases of PJI occurred at 1 year (1.3%). HbA1c at a threshold of 7.7 was distinct for predicting PJI (area under the curve, 0.65; 95% confidence interval, 0.51-0.78). Using this threshold, PJI rates increased from 0.8% (11 of 1441) to 5.4% (11 of 204). In the stepwise logistic regression analysis, PJI remained the only variable associated with higher HbA1c (odds ratio, 1.5; confidence interval, 1.2-2.0; P = .0001). There was no association between high HbA1c levels and other complications assessed. CONCLUSION: High HbA1c levels are associated with an increased risk for PJI. A threshold of 7.7% seems to be more indicative of infection than the commonly used 7% and should perhaps be the goal in preoperative patient optimization.

BACKGROUND: Many cost drivers of total knee arthroplasty (TKA) have been critically evaluated to meet the heightened quality-associated expectations of performance-based care. However, assessing the efficacy of the different modalities of skin closure has been an underappreciated topic. The present study aims to provide further insight by conducting a meta-analysis and systematic review evaluating the rates of common complications and perioperative quality outcomes associated with different suture and staple skin closure techniques after TKA. METHODS: The present study was conducted in accordance with both the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement and the Cochrane Handbook for meta-analyses and systematic reviews. Primary outcome measures evaluated rates of common complications associated with primary TKA. Secondary outcome measures evaluated wound closure time, direct surgical costs, and cosmetic and knee function outcomes. RESULTS: Our meta-analysis demonstrated that skin sutures had a higher likelihood of superficial and deep infections, abscess formation, and wound dehiscence. Conversely, staples had a higher tendency for prolonged wound discharge. A systematic review of wound closure times and overall resource utilization demonstrated that wound closure was faster and more cost-effective with skin staples than sutures. CONCLUSION: Primary skin incision closure with staples demonstrated lower wound complications, decreased wound closure times, and an overall reduction in resource utilization. Given these outcomes, the use of staples after TKA may have several subtle clinical advantages over sutures.

BACKGROUND: A large component of the cost of revision total hip arthroplasty (THA) is the cost of the implants. We examined the pricing of revision THA implants to determine the possible savings of different pricing models. METHODS: From our institutional database, all revision THAs done from 9/1/2013 to 8/31/2014 were identified. The cost of the implants was analyzed as a percentage of the total cost of the hospitalization and compared to direct to hospital and fixed implant pricing models. RESULTS: Of 153 revision THAs analyzed, the cost of implants amounted to 36% of the total hospital cost. The direct to hospital cost and fixed implant pricing models would reduce the cost of an all-component revision to $4395 (saving $8962 per case) and $5000 (saving $8357 per case). CONCLUSION: Both fixed implant pricing and the direct to hospital pricing models would result in a decrease in revision implant costs.

BACKGROUND: Short-term and intermediate-term wear rates for highly cross-linked polyethylene (HCLPE) liners in total hip arthroplasty (THA) are significantly lower than published rates for traditional polyethylene liners. The aim of this study was to report the longest-to-date follow-up of a specific HCLPE liner. METHODS: A series of 35 THAs using a specific HCLPE liner were reviewed. Anteroposterior radiographs were reviewed for femoral head penetration, the presence of femoral and/or acetabular osteolysis, long-term survival, total wear, and wear rates in all patients. RESULTS: The average patient age at time of surgery was 70 years with an average follow-up of 10 years (118 months; range, 7.2-13.4 years). The mean wear rate in our cohort was 0.07 mm/y. Total wear was 0.71 mm over the study period. No hips showed evidence of osteolysis in any zones. Survivorship at latest follow-up was 100% with all-cause revision as an end point. CONCLUSION: The wear rate of HCLPE liners continues to be lower than published wear rates for traditional polyethylene and continues to reaffirm the acceptably low wear rates using HCLPE acetabular liner in primary THA.