Prediction Models for 30-Day Mortality and Complications After Total Knee and Hip Arthroplasties for Veteran Health Administration Patients With Osteoarthritis.

BACKGROUND: Statistical models to preoperatively predict patients' risk of death and major complications after total joint arthroplasty (TJA) could improve the quality of preoperative management and informed consent. Although risk models for TJA exist, they have limitations including poor transparency and/or unknown or poor performance. Thus, it is currently impossible to know how well currently available models predict short-term complications after TJA, or if newly developed models are more accurate. We sought to develop and conduct cross-validation of predictive risk models, and report details and performance metrics as benchmarks. METHODS: Over 90 preoperative variables were used as candidate predictors of death and major complications within 30 days for Veterans Health Administration patients with osteoarthritis who underwent TJA. Data were split into 3 samples-for selection of model tuning parameters, model development, and cross-validation. C-indexes (discrimination) and calibration plots were produced. RESULTS: A total of 70,569 patients diagnosed with osteoarthritis who received primary TJA were included. C-statistics and bootstrapped confidence intervals for the cross-validation of the boosted regression models were highest for cardiac complications (0.75; 0.71-0.79) and 30-day mortality (0.73; 0.66-0.79) and lowest for deep vein thrombosis (0.59; 0.55-0.64) and return to the operating room (0.60; 0.57-0.63). CONCLUSIONS: Moderately accurate predictive models of 30-day mortality and cardiac complications after TJA in Veterans Health Administration patients were developed and internally cross-validated. By reporting model coefficients and performance metrics, other model developers can test these models on new samples and have a procedure and indication-specific benchmark to surpass.

Comparing Methods to Determine the Minimal Clinically Important Differences in Patient-Reported Outcome Measures for Veterans Undergoing Elective Total Hip or Knee Arthroplasty in Veterans Health Administration Hospitals.

Importance: The minimal clinically important difference (MCID) in a patient-reported outcome measure (PROM) is the smallest change that patients perceive as beneficial. Accurate MCIDs are required when PROMs are used to evaluate the value of surgical interventions. Objective: To use well-defined distribution-based and anchor-based methods to calculate MCIDs in the Hip Disability and Osteoarthritis Outcome Score (HOOS) and in the Knee Injury and Osteoarthritis Outcome Score (KOOS) for veterans undergoing primary total hip arthroplasty or total knee arthroplasty. Design, Setting, and Participants: A prospective cohort study was conducted of 858 patients undergoing total joint replacement between March 16, 2015, and March 9, 2017, at 3 high-complexity Veterans Affairs Medical Centers. Interventions: Patients undergoing total hip arthroplasty or total knee arthroplasty were administered HOOS or KOOS PROMs prior to and 1 year after surgery. The Self-Administered Patient Satisfaction Scale (SAPS) for primary hip or knee arthroplasty was administered at 1-year follow-up as an anchor PROM. Main Outcomes and Measures: The HOOS and KOOS before and 1 year after surgery, change scores (difference between postoperative and preoperative PROM scores), and MCIDs for each measure. For anchor-based methods, receiver operating characteristic curve analysis was performed, including calculation of the area under the curve. Results: The mean (SD) age of the 271 patients who underwent hip arthroplasty was 65.6 (8.3) years, and the mean (SD) age of the 587 patients who underwent knee arthroplasty was 66.1 (8.2) years. There were 547 men in the knee arthroplasty cohort and 256 men in the hip arthroplasty cohort (total, 803 men). There were significant improvements in the mean values of every PROM, with mean (SD) differences greater than 39 for HOOS Joint Replacement (JR) and every hip subscale (HOOS JR, 39.7 [20.2]; pain, 47.6 [20.5]; symptoms, 45.1 [21.5]; activities of daily living, 43.7 [22.1]; recreation, 49.2 [33.5]; quality of life, 50.3 [27.8]) and mean (SD) differences greater than 29 for KOOS JR and every knee subscale (KOOS JR, 30.4 [17.5]; pain, 38.0 [20.4]; symptoms, 29.5 [22.1]; activities of daily living, 34.8 [20.5]; recreation, 34.6 [31.1]; quality of life, 35.2 [26.8]). Different calculation methods yielded a wide range of MCIDs. Distribution-based approaches tended to give lower values than the anchor-based approaches, which gave similar values for most PROMs. Area under the curve values demonstrated good to excellent discrimination for SAPS for nearly all PROMs. Conclusions and Relevance: Minimal clinically important difference estimates can be highly variable depending on the method used. Patient satisfaction measured by SAPS is a suitable anchor for the HOOS and KOOS. This study suggests that the SAPS-anchored MCID values presented here be used in future studies of total hip arthroplasty and total knee arthroplasty for veterans.

Systemic Blastomyces Infection Presenting as a Soft-Tissue Infection of the Finger: A Case Report.

CASE: A thirty-eight-year-old male patient presented with fusiform swelling of the left ring finger after minor trauma. After medical evaluation by the emergency department, primary care service, and rheumatology service, he was referred to the orthopaedic service, where he underwent 2 surgical debridements. Cultures from the second surgery revealed a diagnosis of blastomycosis, and the patient was treated with intravenous amphotericin B followed by oral itraconazole. CONCLUSION: Our case report demonstrates a rare presentation and diagnosis of blastomycosis. Knowledge of atypical infections such as this can allow for earlier diagnosis and more appropriate treatment.