A Novel Method for Stratification of Major Complication Risk Using Body Mass Index Thresholds for Patients Undergoing Total Hip Arthroplasty: A National Cohort of 224,413 Patients

Data-Driven Estimated Glomerular Filtration Rate Strata Predict 90-Day Major Complications Following Total Knee Arthroplasty in Patients With Chronic Kidney Disease

INTRODUCTION

Lower estimated glomerular filtration rate (eGFR) in patients who have chronic kidney disease (CKD) is associated with increased risk of complications following total knee arthroplasty (TKA). However, there is a lack of literature that identifies eGFR levels those are associated with notable differences in risk of these complications. The purpose of this study was to create eGFR strata for CKD patients that are associated with varying risks of 90-day major complications following TKA.

METHODS

Nondialysis patients who have CKD and known eGFR levels one month before primary TKA were identified using a national database. Stratum-specific likelihood ratio (SSLR) analysis was used to construct data-driven eGFR strata associated with varying risks of 90-day major complications. The incidence rates were recorded for each stratum. Each stratum was propensity score matched to the highest eGFR stratum. The risk ratio with a corresponding 95% confidence interval for 90-day major complications was recorded for each stratum.

RESULTS

A total of 24,895 patients with CKD who underwent TKA were included in this study. SSLR identified four data-driven eGFR strata: 15-31, 32-44, 45-54, and 55+. The unmatched 90-day major complication incidence increased sequentially as the eGFR strata decreased: 55+ (10.72%), 45-54 (13.87%), 32-44 (17.30%), and 15-31 (25.16%). When compared with the matched highest eGFR strata (55+), the risk of sustaining a 90-day major complication increased sequentially as the eGFR strata decreased (RR: 1.27, 1.56, 2.06, P < 0.001). The risk of death within 90 days was higher in the 15-31 stratum (RR: 3.08, P < 0.001) when compared with the matched 55+ stratum.

CONCLUSION

Using SSLR analysis, four data-driven strata were identified with varying risks of 90-day major complications following TKA. These eGFR thresholds were created specifically for TKA and can therefore be appropriately used to risk-stratify CKD patients in the preoperative setting when discussing TKA.

Identification of Data-Driven Preoperative Hemoglobin Strata That Predict the Likelihood of Blood Transfusion and the Risk of Major Complications and Prosthetic Joint Infection After Total Hip Arthroplasty

INTRODUCTION

Preoperative anemia is an independent risk factor of complications after primary total hip arthroplasty (THA). Currently used hemoglobin thresholds are not developed for risk stratification of arthroplasty patients and do not provide surgery-specific information on postoperative complication risk. Thus, we aimed to calculate THA-specific preoperative hemoglobin strata that observe the likelihood of 90-day blood transfusion and determine whether these strata are associated with increased risk of 90-day complications and 2-year prosthetic joint infection (PJI).

METHODS

A retrospective cohort analysis identified 56,101 patients who underwent primary THA from 2013 to 2022. Using the lowest hemoglobin value for each patient one month before THA, stratum-specific likelihood ratio (SSLR) analysis calculated sex-based hemoglobin strata associated with the likelihood of 90-day postoperative blood transfusion. Propensity score matching was performed. Incidence rates and risk of 90-day major complications and 2-year PJI were observed for each identified preoperative hemoglobin stratum.

RESULTS

SSLR analysis identified five male (strata, likelihood ratio [<10.4 g/dL, 12.5; 10.5 to 11.4 g/dL, 8.0; 11.5 to 12.4 g/dL, 2.4; 12.5 to 13.4 g/dL, 1.3; 13.5 to 13.9 g/dL, 0.5]) and five female (<8.9 g/dL, 10.7; 9.0 to 10.9 g/dL, 4.0; 11.0 to 11.4 g/dL, 2.0; 12.0 to 12.9 g/dL, 1.0; 13.0 to 13.4 g/dL, 0.6) preoperative hemoglobin strata associated with varying likelihoods of 90-day blood transfusion after THA. After matching in both male and female cohorts, as the calculated preoperative hemoglobin strata decreased, the relative risk of overall 90-day major complications and 2-year PJI increased incrementally (all P < 0.05).

CONCLUSION

SSLR analysis established THA-specific sex-based preoperative hemoglobin strata that observe the likelihood of 90-day blood transfusion and predict the risk of 90-day medical complications and 2-year PJI. These strata are a first of their kind in THA research. While preoperatively optimizing patients, we recommend using these hemoglobin thresholds to help guide decisions on presurgery anemia optimization and to reduce the need for postoperative blood transfusion.

LEVEL OF EVIDENCE

Level III.

Preoperative Risk Assessment for Lumbar Fusion in Patients With Diabetes: Data-Driven Stratification of HbA1c and Same Day Glucose Levels that Predict 90-Day Complication Rates

STUDY DESIGNS

Retrospective Database Analysis.

OBJECTIVES

Pre-operative glycemic control in diabetic patients undergoing lumbar fusion (LF) is essential for evaluating complication risk. However, current thresholds for preoperative HbA1c and same-day-glucose (SDG) are either non-specific or have low predictive power. This study uses HbA1c and SDG to provide data-driven risk stratification for 90-day major and wound complications in LF patients.

METHODS

Using a national database, patients undergoing LF from 2013-2022 with a recorded preoperative HbA1c and SDG level were included for analysis. Multiple HbA1c and SDG strata were identified using stratum specific likelihood ratio analysis (SSLR). Each stratum was then propensity-score matched to the lowest strata and compared using risk ratios. Significance level was set at a P-value <0.05.

RESULTS

12,026 patients met inclusion criteria. For 90-day major complications, SSLR identified 3 predictive HbA1c (4.5-5.4, 5.5-7.9, and 8.0+) and SDG strata (60-159, 160-239, and 240+). Following propensity-matching, the 90-day major complication risk sequentially increased for HbA1c: 5.5-7.9 (1.69; P = 0.001; 95% CI 1.24-2.30), 8.0+(2.31; P < 0.001; 95% CI 1.56-3.43). Following propensity-matching, the SDG strata similarly demonstrated sequentially increasing 90-day major complication risk: 160-239 (1.34; P < 0.001; 95% CI 1.18-1.54), 240+ (1.64; P < 0.001; 95% CI 1.31-2.05). Matched analysis demonstrated a higher relative-risk of 90-day wound complications for the 8.0+ HbA1c strata (2.23; P = 0.001; 95% CI 1.37-3.63) compared to the HbA1c 4.5-5.4 strata. No other strata were identified that predicted differences in 90-day wound complications.

CONCLUSIONS

This study identified data-driven HbA1c and SDG strata that better risk-stratify 90-day major complications following LF. Instead of current single-value thresholds, these multiple strata may be utilized for better preoperative guidance.

Evaluating the Effect of Decreasing Preoperative Hemoglobin on Blood Transfusions, Major Complications, and Periprosthetic Joint Infection After Primary Total Knee Arthroplasty

INTRODUCTION

Preoperative anemia is associated with increased postoperative transfusion and complication rates after total knee arthroplasty (TKA). We aimed to create TKA-specific data-driven preoperative hemoglobin strata that quantify the likelihood of 90-day postoperative blood transfusion and evaluate whether these strata are associated with increased risk of 90-day major complications and 2-year prosthetic joint infection (PJI).

METHODS

Primary TKA patients from 2013 to 2022 were identified using a national database. Stratum-specific likelihood ratio (SSLR) analysis defined hemoglobin strata associated with the risk of 90-day blood transfusion. Each stratum was propensity score matched to the highest identified hemoglobin strata. Unmatched incidence rates and matched risk of 90-day major complications and 2-year PJI between strata were compared.

RESULTS

SSLR identified four 90-day blood transfusion hemoglobin strata for men (strata [g/dL], likelihood ratio [<11.4, 8.06; 11.5 to 11.9, 4.34; 12.0 to 12.9, 1.70; 13.0 to 17.0, 0.54]) and women (<10.4, 8.22; 10.5 to 11.4, 2.84; 11.5 to 12.4, 1.38; 12.5 to 17.0, 0.50). Increased 2-year PJI risk was associated with three male strata (<11.4, 11.5 to 11.9, 12.0 to 12.9; all P < 0.001) and three female strata (<10.4, 10.5 to 11.4, 11.5 to 12.4; all P < 0.001). Increased 90-day major complication risk was associated with three male strata (<11.4, 11.5 to 11.9, 12.0 to 12.9; all P < 0.001) and three female strata (<10.4, 10.5 to 11.4, 11.5 to 12.4; all P < 0.001).

CONCLUSIONS

Using SSLR analysis, we identified unique TKA-specific data-driven hemoglobin strata for both men and women that quantify the likelihood of 90-day blood transfusions and predict the risk of both 90-day major complications and 2-year PJI. These strata are a first in the TKA literature and can assist surgeons in stratifying patients' transfusion and complication risk based on their preoperative hemoglobin value. While optimizing patients in the preoperative setting, we recommend using these TKA-specific hemoglobin thresholds to help guide decision making on the need for presurgery anemia optimization and to help reduce the need for blood transfusion.

Data-driven body mass index threshold associated with increased risk of 2-year periprosthetic joint infection following total shoulder arthroplasty

BACKGROUND

Body mass index (BMI) is a modifiable risk factor for medical and infectious complications following total shoulder arthroplasty (TSA). Previous studies investigating BMI were limited to the conventional classification system, which may be outdated for modern day patients. Therefore, the purpose of this study was to identify BMI thresholds that are associated with varying risk of 90-day medical complications and 2-year prosthetic joint infection (PJI) following TSA.

METHODS

A national database was utilized to identify 10,901 patients who underwent primary elective TSA from 2013 to 2022. Patients were only included if they had a BMI value recorded within 1 month prior to TSA. Separate stratum-specific likelihood ratio analyses, an adaptive technique to identify data-driven thresholds, were performed to determine data-driven BMI strata associated with varying risk of 90-day medical complications and 2-year PJI. The incidence rates of these complications were recorded for each stratum. To control for confounders, each BMI strata was propensity-score matched based on age, sex, hypertension, heart failure, chronic obstructive pulmonary disease, and diabetes mellitus to the lowest identified BMI strata for both outcomes of interest. The risk ratio (RR) and 95% confidence interval (CI) were recorded for each matched analysis.

RESULTS

The average age and BMI of patients was 70.5 years (standard deviation ±9.8) and 30.7 (standard deviation ±6.2), respectively. Stratum-specific likelihood ratio analysis identified two BMI strata associated with differences in the rate of 2-year PJI: 19-39 and 40+. The same strata were identified for 90-day major complications. When compared to the matched BMI 19-39 cohort, the risk of 2-year PJI was higher in the BMI 40+ cohort (RR: 2.7; 95% CI 1.39-5.29; P = .020). After matching, there was no significant difference in the risk of 90-day major complications between identified strata (RR: 1.19, 95% CI: 0.86-1.64; P = .288).

CONCLUSION

A data-driven BMI threshold of 40 was associated with a significantly increased risk of 2-year PJI following TSA. This is the first TSA study to observe BMI on a continuum and observe at what point BMI is associated with increased risk of 2-year PJI following TSA. Our identified BMI strata can be incorporated into risk-stratifying models for predicting both PJI and 90-day major complications to minimize both.

Body Mass Index Greater Than 46 Associated With Increased Risk of 30 Day Complications Following Adult Tonsillectomy: A Retrospective Cohort Study

Background: The study aimed to identify data-driven body mass index (BMI) thresholds that are associated with varying risk of 30 day complications following adult tonsillectomy. Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was utilized to conduct a retrospective cohort analysis of patients undergoing adult tonsillectomy from 2005 to 2019. Stratum-specific likelihood ratio (SSLR) analysis was conducted to determine data-driven BMI strata that maximized the likelihood of 30 day complications following adult tonsillectomy. Patient demographics and clinical comorbidities were compared using chi-squared analysis and student t tests, where appropriate, for each stratum. Multivariable regression analysis was conducted to confirm association between identified data-driven strata with 30 day complication rates. Results: In total, 44,161 patients undergoing adult tonsillectomy were included in this study. SSLR analysis identified 2 BMI categories: 18 to 45 and 46+. Relative to the 18 to 45 BMI cohort, the 46+ BMI cohort was more likely to have 30 day all-cause complications after surgery [odds ratio (OR): 1.62, P = .007]. Specifically, the 46+ BMI cohort had significantly higher odds for 30 day major medical complications (OR: 2.86, P = .001), pulmonary domain complications (OR: 1.86, P = .041), unplanned reintubation (OR: 2.65, P = .033), and deep vein thrombosis (OR: 6.54, P = .026). Conclusions: We identified a BMI threshold of 46+ that was associated with a significantly increased risk of 30 day all-cause complications following adult tonsillectomy. These BMI strata can guide preoperative planning and risk-stratifying models for predicting 30 day complications in tonsillectomy surgery.

The incremental risk of fragility fractures in aging men

INTRODUCTION

While the United States Preventative Services Task Force recommends osteoporosis screening for women 65 years and older, there is no definitive recommendation for routine osteoporosis screening in men. The purpose of this study was to determine the age at which the odds of fragility fractures (FFx) increase in men to help guide future policy discussions evaluating an optimal screening strategy in this population.

METHODS

Men older than 49 years were identified in the PearlDiver Patient Records Database. Patients were excluded if they had a prior fragility fracture, if they were at high risk for osteoporosis due to comorbidities, or if they carried a diagnosis of and/or were on treatment for osteoporosis. The prevalence of FFx was trended for each age group. A stratum-specific likelihood ratio (SSLR) analysis was conducted to identify data-driven strata that maximize the incremental FFx risk by age for men. Logistic regression analyses controlling for potential confounders were conducted to test these identified strata.

RESULTS

The incidence of FFx started to increase after the age of 64 years for men. Further, the identified data-driven age strata associated with a significant and incremental difference in fragility fractures were the following: 50-64, 65-69, 70-72, 73-75, 76-78, 79-80, and 81+. When compared to the youngest age stratum (50-64 years), multivariable regression showed the risk of fragility fracture incrementally increased starting in those aged 70-72 (RR, 1.31; 95% CI. 1.21-1.46; p < 0.001) with the highest risk in those aged 81+ (RR, 5.35; 95% CI, 5.10-5.62; p < 0.001).

CONCLUSION

In men without a pre-existing history of osteoporosis, the risk of fragility fractures starts to increase after the age of 70. Further work building upon these data may help to identify a specific age at which routine bone health screening in males can help to minimize fractures and their associated morbidity and mortality.

A Novel Method for Stratification of 30-Day Major Complication Risk Using Body Mass Index Thresholds for Patients Undergoing Total Knee Arthroplasty: A National Cohort of 443,157 Patients

INTRODUCTION

Many organizations have utilized pre-established body mass index (BMI) cut-offs to guide surgical decision making. As there have been many improvements in patient optimization, surgical technique, and perioperative care over time, it is important to reassess these thresholds as well as contextualize them to total knee arthroplasty (TKA). The purpose of this study was to calculate data-driven BMI thresholds that predict significant differences in risk of 30-day major complications following TKA.

METHODS

Patients who underwent primary TKA from 2010 to 2020 were identified in a national database. Stratum-specific likelihood ratio (SSLR) methodology was utilized to determine data-driven BMI thresholds at which the risk of 30-day major complications increased significantly. These BMI thresholds were tested using multivariable logistic regression analyses. A total of 443,157 patients were included, who had a mean age of 67 (range, 18 to 89), mean BMI of 33 (range 19 to 59), and 11,766 (2.7%) of patients had a 30-day major complication RESULTS: SSLR analysis identified four BMI thresholds that were associated with significant differences in 30-day major complications: 19 to 33, 34 to 38, 39 to 50, and 51+. When compared to those who had a BMI between 19 and 33, the odds of sustaining a major complication sequentially and significantly increased by 1.1, 1.3, and 2.1 times (p<0.05 for all) for the other thresholds.

CONCLUSION

This study identified four data-driven BMI strata utilizing SSLR analysis that were associated with significant differences in the risk of 30-day major complications following TKA. These strata can be utilized to guide shared decision making in patients undergoing TKA.

Same-Day Discharge Following Aseptic Revision and Conversion Total Joint Arthroplasty: A Single-Institution Experience

Background

With hospital inpatient capacity increasingly limited and primary total joint arthroplasty (TJA) rapidly transitioning to outpatient settings, the feasibility of outpatient aseptic revision and conversion TJA (rTJA) has been considered. Before the widespread adoption of outpatient rTJA, guidelines must be established to prevent patient harm. To this end, this study describes our initial experience with same-day-discharge (SDD) aseptic rTJA.

Methods

All aseptic rTJAs performed between May 8, 2015, and December 30, 2021, were retrospectively reviewed. Revision indications, patient selection criteria, and outcomes including SDD success rate, predischarge complications, all-cause emergency department visits, inpatient readmissions, and unplanned clinic encounters within 90 days of surgery were recorded.

Results

Thirty-five SDD aseptic rTJAs were performed. Conversion total hip arthroplasty (55.0%) and instability (27.3%) were the most common indications for hip revision. Instability (50%) and conversion total knee arthroplasty (20.8%) were most common for knee revision. SDD was achieved in 97% (34/35) of cases. One hip patient failed SDD due to persistent hypoxia requiring an overnight hospital stay and also underwent closed reduction for dislocation in the emergency department within 90 days of discharge. Two additional patients had unplanned clinic encounters within 90 days of the index procedure. There were no hospital readmissions or reoperations within 90 days.

Conclusions

Our initial experience suggests SDD aseptic rTJA can be safe and effective when modern perioperative outpatient protocols and surgical techniques are implemented. Future studies should further define patient selection criteria to optimize outcomes and minimize complications in this population.