Diagnostic Test Performances for Identifying Periprosthetic Joint Infection in Hip Hemiarthroplasty.

INTRODUCTION: Periprosthetic joint infection (PJI) is a devastating complication of hip hemiarthroplasty (HHA) that is not well-represented in the literature. Therefore, this study aimed to evaluate diagnostic markers for identifying PJI in patients after HHA and compare them with the most recent 2018 International Consensus Meeting on Musculoskeletal Infection criteria. METHODS: A total of 98 patients (64 PJIs, 65.3%) were analyzed. Patients were identified by relevant Current Procedural Terminology and International Classification of Diseases-9/10 codes from 2000 to 2021 across a single healthcare system. Preoperative or intraoperative synovial fluid nucleated cell (NC) count, synovial polymorphonuclear (PMN) percentage, serum erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP), and serum white blood cell count were compared with Student t -test between aseptic and septic cohorts. Diagnostic utility and laboratory cutoff values were determined using receiver-operating characteristic curves and Youden index, respectively. RESULTS: Mean values were significantly higher in the septic cohort for synovial NC count (120,992.2 versus 1,498.0 cells/µL, P < 0.001), synovial PMN percentage (91.3% versus 56.2%, P < 0.001), serum ESR (75.6 versus 36.3 mm/hr, P < 0.001), serum CRP (20.2 versus 125.8 mg/L, P < 0.001), and serum white blood cell count (8.5 versus 11.5 cells/µL, P < 0.001). Synovial NC count, synovial PMN percentage, and serum CRP had excellent PJI discriminatory ability with an area under the curve of 0.99, 0.90, and 0.93, respectively. Optimal cutoffs were 2,700 cells/µL for synovial NC count (100% sensitivity and 94% specificity), 81.0% for synovial PMN percentage (96% sensitivity and 89% specificity), 52.0 mm/hr for serum ESR (75% sensitivity and 80% specificity), and 40.0 mg/L for serum CRP (85% sensitivity and 92% specificity). CONCLUSION: Our findings support the continued use of routine serum and synovial fluid tests for diagnosing PJI in HHA patients. Optimal cutoff values for both synovial fluid biomarkers were very close in alignment with the 2018 International Consensus Meeting criteria. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Visceral Fat as a Risk Factor for Periprosthetic Joint Infection After Total Hip and Knee Arthroplasty.

BACKGROUND: Visceral obesity, a strong indicator of chronic inflammation and impaired metabolic health, has been shown to be associated with poor postoperative outcomes and complications. This study aimed to evaluate the relationship between visceral fat area (VFA) and periprosthetic joint infection (PJI) in total joint arthroplasty (TJA) patients. METHODS: A retrospective study of 484 patients who had undergone a total hip or knee arthroplasty was performed. All patients had a computed tomography scan of the abdomen/pelvis within two years of their TJA. Body composition data (ie, VFA, subcutaneous fat area, and skeletal muscle area) were calculated at the Lumbar-3 vertebral level via two fully automated and externally validated machine learning algorithms. A multivariable logistic model was created to determine the relationship between VFA and PJI, while accounting for other PJI risk factors. Of the 484 patients, 31 (6.4%) had a PJI complication. RESULTS: The rate of PJI among patients with VFA in the top quartile (> 264.1 cm2) versus bottom quartile (< 82.6 cm2) was 5.6% versus 10.6% and 18.8% versus 2.7% in the total hip arthroplasty and total knee arthroplasty cohorts, respectively. In the multivariate model, total knee arthroplasty patients with a VFA in the top quartile had a 30.5 times greater risk of PJI than those in the bottom quartile of VFA (P = .0154). CONCLUSION: VFA may have a strong association with PJI in TJA patients. Using a standardized imaging modality like computed tomography scans to calculate VFA can be a valuable tool for surgeons when assessing risk of PJI.

Sarcopenia is an independent risk factor for failure to achieve the 1-year MCID of the KOOS, JR and PROMIS PF-SF10a after TKA.

BACKGROUND: Sarcopenia, which is a progressive and multifactorial condition of decreased muscle strength, has been identified as an independent predictor for falls, revision, infection, and readmissions following total knee arthroplasty (TKA), but its association to patient reported outcomes (PROMs) is less studied. The aim of this study is to determine if sarcopenia and other measures of body composition are correlated with ability to achieve the 1-year minimal clinically important difference (MCID) of the KOOS JR and PROMIS-PF-SF10a following primary TKA. METHODS: A multicenter retrospective case-control study was performed. Inclusion criteria consisted of patients over the age of 18 undergoing primary TKA, body composition metrics determined by computed tomography (CT), and available pre- and post-operative PROM scores. Predictors of achievement of the 1-year MCID of the KOOS JR and PROMIS PF-SF-10a were determined through a multivariate linear regression. RESULTS: 140 primary TKAs met inclusion criteria. 74 (52.85%) patients achieved the 1-year KOOS, JR MCID and 108 (77.41%) patients achieved the 1-year MCID for the PROMIS PF-SF10a. Sarcopenia was independently associated with decreased odds of achieving the MCID of both the KOOS, JR (OR 0.31, 95%CI 0.10-0.97, p = 0.04) and the PROMIS-PF-SF10a (OR 0.32, 95%CI 0.12-0.85, p = 0.02) CONCLUSIONS: In our study, sarcopenia was independently associated with increased odds of failure to achieve the 1-year MCID of the KOOS, JR and PROMIS PF-SF10a after TKA. Early identification of sarcopenic patients may be beneficial for arthroplasty surgeons so that targeted nutritional counseling and exercises can be recommended prior to TKA.

Often Overlooked Modifiable Risk Factors Before Total Joint Replacement.

Total joint arthroplasty of the hip and knee are common procedures that effectively manage end-stage arthritis of the hip and knee joint by restoring function and mobility. As total joint arthroplasty transitions from fee-for-service to bundled payments, there is increasing pressure to reduce costs while improving outcomes. Therefore, it is important to understand modifiable risk factors and how to optimize patients using a patient-centered approach before total joint arthroplasty.

Are Narrative Letters of Recommendation for Medical Students Interpreted as Intended by Orthopaedic Surgery Residency Programs?

BACKGROUND: Narrative letters of recommendation are an important component of the residency application process. However, because narrative letters of recommendation are almost always positive, it is unclear whether those reviewing the letters understand the writer's intended strength of support for a given applicant. QUESTIONS/PURPOSES: (1) Is the perception of letter readers for narrative letters of recommendation consistent with the intention of the letter's author? (2) Is there inter-reviewer consistency in selection committee members' perceptions of the narrative letters of recommendation? METHODS: Letter writers who wrote two or more narrative letters of recommendation for applicants to one university-based orthopaedic residency program for the 2014 to 2015 application cycle were sent a survey linked to a specific letter of recommendation they authored to assess the intended meaning regarding the strength of an applicant. A total of 247 unstructured letters of recommendation and accompanying surveys were sent to their authors, and 157 surveys were returned and form the basis of this study (response percentage 64%). The seven core members of the admissions committee (of 22 total reviewers) at a university-based residency program were sent a similar survey regarding their perception of the letter. To answer our research question about whether letter readers' perceptions about a candidate were consistent with the letter writer's intention, we used kappa values to determine agreement for survey questions involving discrete variables and Spearman correlation coefficients (SCCs) to determine agreement for survey questions involving continuous variables. To answer our research question regarding inter-reviewer consistency among the seven faculty members, we compared the letter readers' responses to each survey question using intraclass correlation coefficients (ICCs). RESULTS: There was a negligible to moderate correlation between the intended and perceived strength of the letters (SCC 0.26 to 0.57), with only one of seven letter readers scoring in the moderate correlation category. When stratifying the applicants into thirds, there was only slight agreement (kappa 0.07 to 0.19) between the writers and reviewers. There were similarly low kappa values for agreement about how the writers and readers felt regarding the candidate matching into their program (kappa 0.14 to 0.30). The ICC for each question among the seven faculty reviewers ranged from poor to moderate (ICC 0.42 to 0.52). CONCLUSION: Our results demonstrate that the reader's perception of narrative letters of recommendation did not correlate well with the letter writer's intended meaning and was not consistent between letter readers at a single university-based urban orthopaedic surgery residency program. CLINICAL RELEVANCE: Given the low correlation between the intended strength of the letter writers and the perceived strength of those letters, we believe that other options such as a slider bar or agreed-upon wording as is used in many dean's letters may be helpful.

Incidence of insufficient intraoperative neuromuscular paralysis. A retrospective registry analysis.

STUDY OBJECTIVE: Muscular tone that inhibits anesthetic or surgical care characterizes insufficient neuromuscular block. The incidence of insufficient neuromuscular block is unknown, therefore we developed novel electronic search strategies to identify occurrences of insufficient neuromuscular block. Our primary goal was to determine the incidence of intraoperative insufficient neuromuscular block in abdominal and neurovascular surgery. Our secondary goal was to assess factors independently associated with insufficient block. DESIGN: Retrospective cohort. SETTING: Operating rooms in a tertiary care center. PATIENTS: Adults having abdominal, laparoscopic, and interventional neurovascular procedures under general anesthesia with endotracheal intubation between April 2005 and February 2013. MEASUREMENTS: An expert panel of anesthesiologists used a Delphi process to develop criteria to identify insufficient intraoperative neuromuscular block. 10 final criteria were agreed upon and used to determine the incidence of insufficient neuromuscular block. MAIN RESULTS: 48,315 surgeries met our inclusion requirements. Intraoperative insufficient neuromuscular block was identified in 13,538 cases, representing 28% (95% CI: 27.6%, 28.4%) of the operations. Younger age, male sex, type of surgery, longer duration of surgery, pre-existing conditions, and use of volatile anesthetics were independently associated with insufficient block after Bonferroni correction. CONCLUSION: Our results suggest that episodes of insufficient block occur in over a quarter of operations that are generally thought to require muscle relaxation. Without neuromuscular monitoring, it is difficult to separate inadequate anesthesia from inadequate neuromuscular block, and both presumably contributed in many cases.