Joint Replacement Technology in the Ambulatory Surgery Center: Current and Future Applications.

Total joint replacement (TJR) surgery in the ambulatory surgery centers (ASCs) has grown significantly over the past several years, along with the ability to improve the value of care. Standardization of high-quality, perioperative care is pivotal to the success of a TJR ASC program. As surgeons are experiencing increasing overhead with decreasing reimbursement, technology integration can provide major advantages. In this article, we will therefore highlight several examples of technologies that are changing the field and improving care in the preoperative, intraoperative, and postoperative settings.

Improved short-term outcomes for a novel, fluoroscopy-based robotic-assisted total hip arthroplasty system compared to manual technique with fluoroscopic assistance.

BACKGROUND: While robotic-assisted total hip arthroplasty (RA-THA) has been associated with improved accuracy of component placement, the perioperative and early postoperative outcomes of fluoroscopy-based RA-THA systems have yet to be elucidated. METHODS: This retrospective cohort analysis included a consecutive series of patients who received manual, fluoroscopy-assisted THA (mTHA) and fluoroscopy-based RA-THA at a single institution. We compared rates of complications within 90 days of surgery, length of hospital stay (LOS), and visual analog scale (VAS) pain scores. RESULTS: No differences existed between groups with respect to demographic data or perioperative recovery protocols. The RA-THA cohort had a significantly greater proportion of outpatient surgeries compared to the mTHA cohort (37.4% vs. 3.8%; p < 0.001) and significantly lower LOS (26.0 vs. 39.5 h; p < 0.001). The RA-THA cohort had a smaller 90-day postoperative complication rate compared to the mTHA cohort (0.9% vs. 6.7%; p = 0.029). The RA-THA cohort had significantly lower patient-reported VAS pain scores at 2-week follow-up visits (2.5 vs. 3.3; p = 0.048), but no difference was seen after 6-week follow visits (2.5 vs. 2.8; p = 0.468). CONCLUSION: Fluoroscopy-based RA-THA demonstrates low rates of postoperative complications, improved postoperative pain profiles, and shortened LOS when compared to manual, fluoroscopy-assisted THA.

Predicting Implant Size in Total Hip Arthroplasty.

Background: Efficient resource management is becoming more important as the demand for total hip arthroplasty (THA) increases. The purpose of this study is to evaluate the ability of linear regression and Bayesian statistics in predicting implant size for THA using patient demographic variables. Material and methods: A retrospective, single-institution joint-replacement registry review was performed on patients who underwent primary THA from 2005 to 2019. Demographic information was obtained along with primary THA implant data. A total of 11,730 acetabular and 8536 femoral components were included. A multivariable regression model was created on a training cohort of 80% of the sample and applied to the validation cohort (remaining 20%). Bayesian posterior probability methods were applied to the training cohort and then tested in the validation cohort to determine the 1%, 5%, and 10% error tolerance thresholds. Results: The most predictive regression model included height, weight, and sex (cup: R2 = 0.57, all P < .001; stem mediolateral size [M/L]: R2 = 0.32, all P < .001). Removing weight had a minimal effect and resulted in a more parsimonious model (cup: R2 = 0.56, all P < .001; stem M/L: R2 = 0.32, all P < .001). Applying the posterior probability estimate to the validation cohort in the Bayesian model using height, weight, and sex demonstrated high accuracy in predicting the range of required implant sizes (95.3% cup and 90.4% stem M/L size). Conclusion: Implant size in THA is correlated with demographic variables to accurately predict implant size using Bayesian modeling. Predictive models such as linear regression and Bayesian modeling can be used to improve operating room efficiency, supply chain inventory management, and decrease costs associated with THA.

A Postmortem Analysis of Polyethylene Damage and Periprosthetic Tissue in Rotating Platform and Fixed Bearing Tibial Inserts.

BACKGROUND: Mobile bearing designs are intended to reduce wear, but mixed results were reported from retrieval analyses. Postmortem evaluation (PM) provides the opportunity to assess polyethylene damage in successful implants. We compared damage patterns, MRI presentation, and histology between mobile-bearing and fixed tibial inserts retrieved postmortem and compared these results to our prior findings from implants retrieved at revision. METHODS: Eleven postmortem knees with rotating platform (RP) implants and 13 with fixed bearing (FB) implants were examined. All were MRI scanned, and tissue samples were collected from standardized regions for histology. Polyethylene inserts were subjectively scored to assess articular, backside, and PS post surfaces for damage modes and severity. RESULTS: Average duration of implantation was 9.3 years (1.7-19.6 years). Surface burnishing was the most common polyethylene damage mode. Average damage scores were higher for RP (53.4) compared to FB inserts (34.4) due to greater backside damage (13.4 for RP vs 1.4 for FB). A minimal difference in damage was observed on the articular surfaces (37.4 RP vs 30.0 FB). Mild innate macrophage reactions were seen in 8 (72.7%) RP and 5 (45.5%) FB specimens. Polyethylene particles were identified in 7 (63.6%) RP and 3 (27.7%) FB specimens. CONCLUSIONS: Postmortem inserts showed low damage levels and mild tissue reactions compared to those reported for implants removed at revision arthroplasty. Nonetheless, trends in comparing RP and FB inserts were consistent with those seen in retrieval analyses, demonstrating the usefulness of retrieval studies in capturing performance differences among TKA designs.

Who Cares for Total Hip Arthroplasty Complications? Rates of Readmission to a Hospital Different From the Location of the Index Procedure.

INTRODUCTION: While the number of total hip arthroplasties (THAs) performed increases, so is the number of postoperative readmissions, resulting in costly episodes of care that may disproportionately affect certain hospitals. This study examines the rates of readmission of patients to the same hospital at which they underwent index THA, compared with readmission to a different hospital. METHODS: Data for all hospital discharges from 1995 to 2010 were obtained from the California Office of Statewide Health Planning and Development database. Patient outcomes, readmission data, demographic information, hospital teaching status, and location were analyzed. Regression modeling was used to evaluate the effect of hospital teaching status, location, and individual complications on the risk of readmission to the same hospital as opposed to a different hospital following the index procedure. RESULTS: The overall postoperative readmission rate for specific defined complications or all-cause 30-day readmissions was 3.92%, with 75.17% readmitted to the same hospital. Following index THA at a nonacademic or academic hospital, 95.9% and 84.6% of patients were readmitted to the same type of hospital, respectively. Patients who had their index procedure at an academic hospital had lower odds for readmission to the same hospital (odds ratio, 0.734; P < 0.0001) compared with nonacademic centers. Hospitals in midsize towns had higher odds of readmission to the same hospital (odds ratio, 1.735; P = 0.0012) compared with those in large metropolitan areas. DISCUSSION: Although more than 75% of patients with unplanned readmissions went to the same hospital as their index THA, academic and larger metropolitan hospitals had higher odds of postoperative readmissions to a different hospital.

Nonarthroplasty Options for the Athlete or Active Individual with Shoulder Osteoarthritis.

The management of glenohumeral osteoarthritis is difficult in young, active individuals. After nonoperative management fails, arthroscopic debridement with concomitant procedures (eg, loose body removal, capsular release, labral debridement, synovectomy, osteophyte resection, bursectomy, subacromial decompression, microfracture, and biceps tenotomy or tenodesis) to address potential pain generators may be an option in small, contained, unipolar lesions.

Predictors and Sequelae of Postoperative Delirium in Geriatric Hip Fracture Patients.

INTRODUCTION: Perioperative delirium in elderly hip fracture patients has been correlated with significant morbidity. The purpose of this study was to determine the preoperative risk factors for and short-term sequelae of postoperative delirium in geriatric hip fracture patients. METHODS: We queried the American College of Surgeons National Surgical Quality Improvement Program to identify geriatric (≥65 years) patients who sustained operative hip fractures in 2016. Cohorts of patients with and without documented postoperative delirium were identified. Primary data on patient demographics and comorbidities were collected and correlated with postoperative complications and hip fracture outcome measures. Multivariate regression was used to compute risk-adjusted odds ratios (OR) of risk factors and sequelae of delirium. RESULTS: In total, 8,439 geriatric hip fracture patients were identified of whom 2,569 patients (30.4%) had postoperative delirium. Age (OR 1.03 [1.02-1.04, p < 0.001), white race (OR 1.54 [1.19-2.00], p = 0.001), American Society of Anesthesiologists classification (OR 1.20 [1.07-1.36], p = 0.003), baseline dementia (OR 2.46 [2.11-2.86], p < 0.001), and preoperative delirium (OR 10.06 [8.12-12.45], p < 0.001) were independent risk factors for postoperative delirium in multivariate analysis. Patients with postoperative delirium had a significantly higher risk-adjusted 30-day mortality (12.0% vs. 4.8%, OR 2.22 [1.74-2.84], p < 0.001) and morbidity profile. Postoperative delirium was also independently associated with higher rates of discharge to (OR 1.65 [1.32-2.06], p < 0.001) and prolonged stay in (OR 1.79 [1.53-2.09], p < 0.001) an inpatient facility, hospital readmission (OR 1.94 [1.58-2.38], p < 0.001) and hospital length of stay (7.6 ± 5.0 vs. 6.1 ± 4.1 days, p < 0.001), as well as lower rates of immediate postoperative weight bearing (OR 0.73 [0.63-0.86], p < 0.001). DISCUSSION: Postoperative delirium is a common occurrence in geriatric hip fractures with multiple risk factors. Delirium portends higher mortality and worse perioperative hospital-based outcomes. CONCLUSIONS: Multidisciplinary foreknowledge and management efforts are warranted to mitigate the risk of developing delirium, which strongly predicts perioperative morbidity, mortality, and hip fracture outcomes.

Lower Quarter Y-Balance Test Scores and Lower Extremity Injury in NCAA Division I Athletes.

BACKGROUND: Functional movement tests that are predictive of injury risk in National Collegiate Athletic Association (NCAA) athletes are useful tools for sports medicine professionals. The Lower Quarter Y-Balance Test (YBT-LQ) measures single-leg balance and reach distances in 3 directions. PURPOSE: To assess whether the YBT-LQ predicts the laterality and risk of sports-related lower extremity (LE) injury in NCAA athletes. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: The YBT-LQ was administered to 294 NCAA Division I athletes from 21 sports during preparticipation physical examinations at a single institution. Athletes were followed prospectively over the course of the corresponding season. Correlation analysis was performed between the laterality of reach asymmetry and composite scores (CS) versus the laterality of injury. Receiver operating characteristic (ROC) analysis was used to determine the optimal asymmetry cutoff score for YBT-LQ. A multivariate regression analysis adjusting for sex, sport type, body mass index, and history of prior LE surgery was performed to assess predictors of earlier and higher rates of injury. RESULTS: Neither the laterality of reach asymmetry nor the CS correlated with the laterality of injury. ROC analysis found optimal cutoff scores of 2, 9, and 3 cm for anterior, posteromedial, and posterolateral reach, respectively. All of these potential cutoff scores, along with a cutoff score of 4 cm used in the majority of prior studies, were associated with poor sensitivity and specificity. Furthermore, none of the asymmetric cutoff scores were associated with earlier or increased rate of injury in the multivariate analyses. CONCLUSION: YBT-LQ scores alone do not predict LE injury in this collegiate athlete population. Sports medicine professionals should be cautioned against using the YBT-LQ alone to screen for injury risk in collegiate athletes.

Prevalence of thoracic scoliosis in adults 25 to 64 years of age detected during routine chest radiographs.

PURPOSE: To investigate the prevalence of thoracic scoliosis and determine the effect of both age and gender on coronal curve magnitude among asymptomatic adults aged 25-64 years old, using standing posterior-anterior chest radiographs. METHODS: This was a retrospective, cross-sectional study evaluating 500 randomly selected digital posterior-anterior chest radiographs taken at a single institution on an outpatient basis between January 2010 and December 2011. Males (n = 184) and females (n = 316) ranged in age from 25 to 64 years. Patients with symptoms of back pain; including a history of back pain, spinal instrumentation, or known pre-existing spinal disease were excluded. Radiographs were evaluated using Centricity PACS Web Diagnostic 2.1 system (General Electric Co. Fairfield, CT). Coronal Cobb angle measurements of the thoracic spine were quantified by the authors, with scoliosis defined as coronal curves greater than 10°. Curvatures were subdivided into groups: a control group with coronal curves less than 10°, curves measuring 10° to 19°, 20° to 29°, and greater than 30°. The effect of age and gender on curve magnitude was examined using Pearson correlation analysis and linear regression analysis. RESULTS: There was a 13.4 % (67 patients) prevalence of thoracic scoliosis. The prevalence among asymptomatic males was 10.9 %, while the prevalence among asymptomatic females was 14.9 %. 11.6 % demonstrated a coronal curvature between 10° and 19° (58 patients), 1.6 % between 20° and 29° (8 patients), and 0.2 % greater than 30° (1 patient). Age and gender were not found to be significant independent predictors of curve severity. CONCLUSIONS: We found a 13.4 % prevalence of thoracic scoliosis among asymptomatic adults aged 25-64 years on routine outpatient chest radiographs. 11.6 % of patients demonstrated a coronal curvature between 10° and 19°. Unlike prior studies evaluating asymptomatic thoracic curves in elderly patients, age and gender did not significantly affect curve magnitude in our younger cohort. These data may provide a reference point to help clinicians counsel asymptomatic patients diagnosed with thoracic scoliosis on routine chest radiographs.

Evaluation of preoperative and intraoperative red blood cell transfusion practices at Maputo Central Hospital, Mozambique.

BACKGROUND: The purpose of this study was to evaluate preoperative and intraoperative blood transfusion practices in Hospital Central (Maputo, Mozambique) and estimate the number of potentially avoidable transfusions. STUDY DESIGN AND METHODS: A retrospective cohort study was performed. Age, comorbidities, hemoglobin (Hb), the potential for blood loss, and units of red blood cell (RBC) transfusions were recorded. Preoperative transfusions were evaluated to determine whether they met criteria established by the Mozambican Ministry of Health as well as proposed guidelines based on more restrictive protocols. Avoidable blood transfusions were defined as those preoperative transfusions that were not indicated based on these guidelines. Multivariate logistic regression was used to identify factors that predicted transfusion. RESULTS: A total of 205 patients (age range, 0.1-86 years) underwent surgery in the main operating room during the 2-week study period. Overall, 35 (17%) patients received 68 transfusions. Of these, 36 transfusions were given preoperatively and 32 were given intraoperatively. Thirty-six percent of preoperative transfusions were avoidable according to national guidelines. Ninety-two percent were avoidable using more restrictive guidelines. The primary predictors of preoperative blood transfusion were lower Hb (odds ratio [OR], 0.390/1 g/dL; p < 0.0001) and the potential for blood loss (OR, 3.73; p = 0.0410). CONCLUSIONS: Adherence to existing Hb thresholds recommended by national blood transfusion guidelines could significantly reduce the number of transfusions and the association risk of transfusion-transmissible infections. Adoption of more restrictive guidelines is recommended to further improve blood transfusion utilization and further reduce the transmission risk of human immunodeficiency virus and hepatitis.

Alemtuzumab (CAMPATH 1H) does not kill chronic lymphocytic leukemia cells in serum free medium.

The mechanism of action of alemtuzumab (CAMPATH 1H) in chronic lymphocytic leukemia (CLL) is uncertain. We tested the hypothesis that alemtuzumab alone can induce apoptosis in cultured CLL cells. Purified peripheral blood B-lymphocytes from CLL patients were treated in serum free medium (AIM-V). There was minimal spontaneous apoptosis in untreated cells. Alemtuzumab ligation did not alter the membrane distribution of CD52 in single cells but many cells formed transient, small, tightly adherent clusters. Alemtuzumab alone did not induce apoptosis. In contrast, alemtuzumab plus complement was rapidly cytotoxic. We conclude that alemtuzumab does not cause apoptosis in purified CLL B cells cultured in serum free medium.

The distinct gene expression profiles of chronic lymphocytic leukemia and multiple myeloma suggest different anti-apoptotic mechanisms but predict only some differences in phenotype.

We compared gene expression in purified tumor cells from untreated patients with chronic lymphocytic (CLL) (n=24) and newly diagnosed multiple myeloma (MM) (n=29) using the Affymetrix HuGeneFL microarray with probes for approximately 6800 genes. Hierarchical clustering analysis showed that CLL and MM have distinct expression profiles (class prediction). Gene and protein expression (measured by flow cytometry) correlated well for CD19, CD20, CD23, and CD138 in CLL and MM, but not for immunoglobulin light chain, CD38 and CD79b in CLL, or CD45 and CD52 in MM. CLL and MM differentially expressed 18% of 130 apoptosis related genes, suggesting differences in mechanisms of cell survival.