Synovial Fluid Absolute Neutrophil Count and Neutrophil-To-Lymphocyte Ratio are not Superior to Polymorphonuclear Percentage in Detecting Periprosthetic Joint Infection.

BACKGROUND: Serum and synovial biomarkers are currently used to diagnose periprosthetic joint infection (PJI). Serum neutrophil-to-lymphocyte ratio (NLR) has shown promise as an inexpensive test in diagnosing infection, but there are no reports of synovial NLR or absolute neutrophil count (ANC) for diagnosing chronic PJI. The purpose of this study was to investigate the diagnostic potential of both markers. METHODS: A retrospective review of 730 patients who underwent total joint arthroplasty and subsequent aspiration was conducted. Synovial white blood cell (WBC) count, synovial polymorphonuclear percentage (PMN%), synovial NLR, synovial ANC, serum erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP), serum WBC, serum PMN%, serum NLR, and serum ANC had their utility in diagnosing PJI examined by area-under-the-curve analyses (AUC). Pairwise comparisons of AUCs were performed. RESULTS: The AUCs for synovial WBC, PMN%, NLR, and ANC were 0.84, 0.84, 0.83, and 0.85, respectively. Synovial fluid ANC was a superior marker to synovial NLR (P = .027) and synovial WBC (P = .003) but not PMN% (P = .365). Synovial NLR was inferior to PMN% (P = .006) but not different from synovial WBC (P > .05). The AUCs for serum ESR, CRP, WBC, PMN%, NLR, and ANC were 0.70, 0.79, 0.63, 0.72, 0.74, and 0.67, respectively. Serum CRP outperformed all other serum markers (P < .05) except for PMN% and NLR (P > .05). Serum PMN% and NLR were similar to serum ESR (P > .05). CONCLUSION: Synovial ANC had similar performance to PMN% in diagnosing chronic PJI, whereas synovial NLR was a worse diagnostic marker. The lack of superiority to synovial PMN% limits the utility of these tests compared to established criteria.

Diagnostic Utility and Thresholds for Commonly Obtained Serum and Synovial Markers Prior to Reimplantation in Periprosthetic Joint Infection.

BACKGROUND: Accurate diagnosis of persistent periprosthetic joint infection (PJI) during 2-stage exchange remains a challenge. This study evaluated the diagnostic performance and thresholds of several commonly obtained serum and synovial markers to better guide reimplantation timing. METHODS: This was a retrospective review of 249 patients who underwent 2-stage exchange with antibiotic spacers for PJI. Serum and synovial markers analyzed included white blood cell (WBC) count, polymorphonuclear percentage (PMN%), neutrophil-to-lymphocyte ratio (NLR), and absolute neutrophil count (ANC). Serum markers analyzed were erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), as well as percentage change in ESR and CRP from initial diagnosis to reimplantation. Area under the curve (AUC) analyses were performed to determine diagnostic accuracy of detecting PJI. RESULTS: In TKAs, synovial ANC and WBC had the highest AUCs (0.76), with thresholds of 2,952 and 3,800 cells/µL, respectively. The next best marker was serum CRP (0.73) with a threshold of 5.2 mg/dL. In THAs, serum CRP had the highest AUC (0.84) with a threshold of 4.3 mg/dL, followed by synovial PMN% (0.80) with a threshold of 77%. Percentage change in serum ESR or CRP provided low diagnostic value overall. CONCLUSION: Regarding serum markers, CRP consistently performed well in detecting persistent PJI in patients with antibiotic spacers. Absolute values of serum CRP and ESR had better diagnostic value than trends for guiding reimplantation timing. Diagnostic performance differed with joint type; however, synovial markers outperformed serum counterparts. No marker alone can be utilized to diagnose residual PJI in these patients, and further work is needed in this domain.

Trends in outpatient shoulder arthroplasty during the COVID-19 (coronavirus disease 2019) era: increased proportion of outpatient cases with decrease in 90-day readmissions.

BACKGROUND: The COVID-19 (coronavirus disease 2019) pandemic has placed an increased burden on health care resources, with hospitals around the globe canceling or reducing most elective surgical cases during the initial period of the pandemic. Simultaneously, there has been an increased interest in performing outpatient total joint arthroplasty in an efficient manner while maintaining patient safety. The purpose of this study was to investigate trends in total shoulder arthroplasty (TSA) during the COVID-19 era with respect to outpatient surgery and postoperative complications. METHODS: We conducted a retrospective chart review of all primary anatomic and reverse TSAs performed at our health institution over a 3-year period (January 2018 to January 2021). All cases performed prior to March 2020 were considered the "pre-COVID-19 era" cohort. All cases performed in March 2020 or later comprised the "COVID-19 era" cohort. Patient demographic characteristics and medical comorbidities were also collected to appropriately match patients from the 2 cohorts. Outcomes measured included type of patient encounter (outpatient vs. inpatient), total length of stay, and 90-day complications. RESULTS: A total of 567 TSAs met the inclusion criteria, consisting of 270 shoulder arthroplasty cases performed during the COVID-19 era and 297 cases performed during the pre-COVID-19 era. There were no significant differences in body mass index, American Society of Anesthesiologists score, smoking status, or distribution of pertinent medical comorbidities between the 2 examined cohorts. During the COVID-19 era, 31.8% of shoulder arthroplasties were performed in an outpatient setting. This was significantly higher than the percentage in the pre-COVID-19 era, with only 4.5% of cases performed in an outpatient setting (P < .0001). The average length of stay was significantly reduced in the COVID-19 era cohort (0.81 days vs. 1.45 days, P < .0001). There was a significant decrease in 90-day readmissions during the COVID-19 era. No significant difference in 90-day emergency department visits, 90-day venous thromboembolism events, or 90-day postoperative infections was observed between the 2 cohorts. CONCLUSION: We found a significant increase in the number of outpatient shoulder arthroplasty cases being performed at our health institution during the COVID-19 era, likely owing to a multitude of factors including improved perioperative patient management and increased hospital burden from the COVID-19 pandemic. This increase in outpatient cases was associated with a significant reduction in average hospital length of stay and a significant decrease in 90-day readmissions compared with the pre-COVID-19 era. The study data suggest that outpatient TSA can be performed in a safe and efficient manner in the appropriate patient cohort.

The AAHKS Clinical Research Award: Are Minimum Two-Year Patient-Reported Outcome Measures Necessary for Accurate Assessment of Patient Outcomes After Primary Total Knee Arthroplasty?

BACKGROUND: The two-year minimum follow-up after total knee arthroplasty (TKA) required by most academic journals is based on implant survivorship studies rather than patient-reported outcome measures (PROMs). Additionally, the COVID-19 pandemic placed an unprecedented burden on patients and staff and halted asymptomatic surveillance clinic visits to minimize exposure. The purpose of this study was to determine if clinically meaningful differences were observed in PROMs beyond one year after TKA. METHODS: A retrospective review was performed on prospectively collected PROMs after 1093 primary TKAs at a suburban academic center. PROMs related to pain, function, activity level, and satisfaction were compared by subsequent follow-up intervals preoperatively, at 4 months, 1 year, and minimum 2 years using paired data analysis techniques. RESULTS: Pain with level walking and while climbing stairs improved from preoperative levels to 4-month, 1-year, and minimum 2-year follow-up. The University of California Los Angeles activity level and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement improved over the same intervals. Patient satisfaction improved over postoperative follow-up intervals (84.0%, 87.3%, and 90.9%). While PROMs improved with statistical and clinical significance preoperatively to 4-month to 1-year follow-up, improvements from 1-year to minimum 2-year follow-up were small and did not reach minimum clinically important differences for nearly all PROMs, demonstrating significant overlap of the 95% confidence intervals. CONCLUSION: While long-term follow-up after TKA remains important for implant survivorship, it appears that one-year PROMs are as clinically reliable and meaningful as two-year PROMs. Therefore, it is reasonable to question the currently accepted 2-year minimum follow-up requirement used in peer-reviewed research involving PROMs. LEVEL OF EVIDENCE: Level III.

Peri-implant fractures of the upper and lower extremities: a case series of 61 fractures.

PURPOSE: To assess outcomes for patients who sustained peri-implant fractures (PIFs). METHODS: Medical records of patients who sustained a PIF were reviewed for demographic, injury, outcome, and radiographic data. PIFs were classified using a reproducible system and stratified into cohorts based on fracture location. Clinical outcomes were evaluated for each cohort. RESULTS: Fifty-six patients with 61 PIFs with at least 6 months of follow-up were included. The mean age of the cohort was 60.4 ± 19.5 years. Twenty-two (36.1%) PIFs occurred in males, while 39 (63.9%) occurred in females. Fifty-two (85.2%) PIFs were sustained from a low-energy injury mechanism. PIFs were most often treated with plate/screw constructs (50.8%). Complications included: 6 (9.8%) nonunions, 5 of which were successfully treated to healing, 5 (8.2%) fracture related infections (FRI), and 1 (1.6%) hardware failure. Sixty (98.4%) PIFs ultimately demonstrated radiographic healing. CONCLUSION: PIFs are usually treated surgically and have a relatively high incidence of complications, with nonunion in femoral PIFs being the greatest. Despite this, the rate of ultimate healing is quite high.

Skeletal Traction for Isolated Femur Fractures Does Not Reduce Opioid Consumption.

OBJECTIVES: Isolated femoral shaft fractures can be treated preoperatively with skeletal traction (TXN) or maintenance of a position of comfort (COMF). The goal of this retrospective review was to determine whether preoperative opioid consumption differs significantly between these forms of treatment. DESIGN: Case-control retrospective study. SETTING: Two academic Level 1 trauma centers. PATIENT SELECTION CRITERIA: Patients presenting to the emergency department with isolated OTA/AO 32A-C femoral shaft fractures from 2017 to 2020. OUTCOME MEASURES AND COMPARISONS: The primary outcome was preoperative opioid consumption (morphine milligram equivalents) comparing patients treated with application of TXN or placed in a position of COMF. RESULTS: Two hundred and twenty patients were studied (COMF n = 167, TXN n = 53). Multivariate regression analysis revealed significantly greater preoperative opioid consumption in the emergency department for the TXN group compared with COMF (2.6 more morphine milligram equivalents [confidence interval, 0.23-4.96], P = 0.031). There was no difference in preoperative opioid consumption between groups on the hospital floor ( P = 0.811) nor during the entire preoperative course ( P = 0.486). The total preoperative rate of opioid consumption (morphine milligram equivalents/hour) did not differ ( P = 0.825). CONCLUSIONS: Patients with isolated femoral shaft fractures treated preoperatively with skeletal traction consumed more opioids in the emergency department compared with patients treated in a position of comfort, but no difference in opioid consumption was observed between groups for the entire preoperative course. A position of comfort may be considered as an acceptable alternative to skeletal traction for patients with isolated femur fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

A Reproducible Cartilage Impact Model to Generate Post-Traumatic Osteoarthritis in the Rabbit.

Post-traumatic osteoarthritis (PTOA) is responsible for 12% of all osteoarthritis cases in the United States. PTOA can be initiated by a single traumatic event, such as a high-impact load acting on articular cartilage, or by joint instability, as occurs with anterior cruciate ligament rupture. There are no effective therapeutics to prevent PTOA currently. Developing a reliable animal model of PTOA is necessary to better understand the mechanisms by which cartilage damage proceeds and to investigate novel treatment strategies to alleviate or prevent the progression of PTOA. This protocol describes an open, drop tower-based rabbit femoral condyle impact model to induce cartilage damage. This model delivered peak loads of 579.1 ± 71.1 N, and peak stresses of 81.9 ± 10.1 MPa with a time-to-peak load of 2.4 ± 0.5 ms. Articular cartilage from impacted medial femoral condyles (MFCs) had higher rates of apoptotic cells (p = 0.0058) and possessed higher Osteoarthritis Research Society International (OARSI) scores of 3.38 ± 1.43 compared to the non-impacted contralateral MFCs (0.56 ± 0.42), and other cartilage surfaces of the impacted knee (p < 0.0001). No differences in OARSI scores were detected among the non-impacted articular surfaces (p > 0.05).

Use of a Nanofiber Resorbable Scaffold During Rotator Cuff Repair: Surgical Technique and Results After Repair of Small- to Medium-Sized Tears.

Background: The rate of retear after primary rotator cuff failure remains unacceptably high (up to 36% for small- to medium-sized tears). Augmentation of cuff repair with scaffold devices has been reported to improve healing after cuff repair. Purpose/Hypothesis: To describe the surgical technique of using an interpositional nanofiber scaffold during rotator cuff repair and report on a retrospective series of patients regarding functional outcomes and postoperative healing on magnetic resonance imaging (MRI). We hypothesized that augmentation of cuff repair with an interpositional scaffold would result in a high rate of tendon healing and excellent functional outcomes. Study Design: Case series; Level of evidence, 4. Methods: A total of 33 patients underwent arthroscopic rotator cuff repair augmented with a nanofiber, bioresorbable polymer patch secured as an inlay between the tendon and underlying bone. Patients were evaluated preoperatively and postoperatively with the Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES) shoulder score, and active range of motion (ROM) measurements. Postoperative MRI was used to evaluate repair status. Results: At a minimum follow-up of 6 months, the patients showed significant improvement on SST and ASES scores (P < .0001 for both). ROM in forward flexion, abduction, internal rotation, and external rotation significantly improved at 6 months postoperatively (P < .05 for all). MRI at an average of 11 months postoperatively showed healing in 91% of patients; one patient had a recurrent tear with transtendon failure, and another patient had retear at the insertional site. The patch was not visible on postoperative imaging, suggesting complete resorption in all patients. No adverse events were associated with the patch. Conclusion: Our results demonstrate the preliminary safety and efficacy of a novel, bioresorbable synthetic scaffold for rotator cuff repair. The use of the scaffold resulted in a 91% tendon healing rate and significant improvements in functional and patient-reported outcome measures. The results are promising for improving the current unacceptably high rate of rotator cuff repair failure.

Previous Implant Fractures: A New Descriptive Classification System.

OBJECTIVES: To propose a previous implant fractures (PIFs) classification system with good interobserver reliability. DESIGN: Retrospective classification. SETTING: Four academic medical centers. PATIENTS/PARTICIPANTS: A retrospective review of PIFs treated at 4 academic medical centers over 10 years was performed. Data collected included initial implant and PIF radiographs. There were 103 PIFs in 96 patients during the study period. Seventy-three (70.9%) were about plate/screw (PS) constructs and 30 (29.1%) were about intramedullary (IM) devices. INTERVENTION: Assignment of PIF classification. MAIN OUTCOME MEASUREMENTS: PIFs were classified based on initial implant (PS or IM) and fracture location with respect to the initial implant (proximal or distal to the implant, at the tip of the construct, or within the construct). Reliability of this scheme was assessed among 5 observers using Fleiss' kappa tests. RESULTS: Of PIFs about plate/screw constructs, 26.0% were proximal/distal to the implant (classification: PS1), 57.5% involved bone between the most proximal/distal screw and the same end of the plate (classification: PS2), and 16.4% involved only bone between the most proximal and distal screws (classification: PS3). Of PIFs about IM, 43.3% were distal to the device (classification: IM1), 46.7% involved bone between the most proximal/distal locking bolt and the same end of the device (classification: IM2), and 10.0% involved only bone between locking bolts (classification: IM3). Interobserver reliability for the classification system was excellent between observers, κ = 0.839, P < 0.0005. CONCLUSIONS: The proposed system offers a simple method to classify and describe fractures that occur about a previously implanted fracture device. Development of a classification system will allow for comparison of treatment modalities between injury types.

Authorship trends in the Journal of Orthopaedic Research: A bibliometric analysis.

Publications are an important tool to measure one's success and achievement in academia. They can help propel a career forward and move one into a position of leadership. The overall purpose of this study was to investigate changes in bibliometric variables, authorship, and collaboration trends in the Journal of Orthopaedic Research (JOR®), since its inception in 1983. A bibliometric analysis was completed for all manuscripts meeting the inclusion criteria (638), which were published throughout the inaugural year plus one representative year of each decade. Several parameters were investigated including numbers of manuscripts, authors, collaborating institutions/countries, references, pages, and citations; region of origin and gender of authors over time and by region were main focuses. Significant increases over time were observed in all bibliometric variables analyzed except in the number of pages and citations. There was an approximate 27% point increase for both female first and corresponding authors from 1983 to 2015. While this is most likely due to the increase in the number of women that have entered the field over time, similar increases in the percentage of women holding positions on the JOR editorial board or in leadership positions within in the field may have also contributed to improvements in gender parity. Understanding changes in publishing characteristics over time, by region, and by gender are critical, especially with the rising demands of publishing in academia. JOR has seen increase in most variables analyzed, including improvements in authorship by women in the field of orthopaedic research. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3071-3080, 2018.