Outcomes After Successful Debridement, Antibiotic, and Implant Retention Therapy for Periprosthetic Joint Infection in Total Knee Arthroplasty.

BACKGROUND: Controversy surrounds debridement, antibiotic and implant retention (DAIR) for treatment of acute periprosthetic joint infection (PJI). Data regarding DAIR's rate of infection resolution is variable with little investigation of functional outcomes. METHODS: We identified 191 DAIR cases at a single institution from 2008 to 2020. Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) and Patient Reported Outcome Measurement Information System-10 (PROMIS) scores were collected. Patient Reported Outcome Scores were obtained from 60 cases. Median follow-up (IQR) was 4.5 (2.1 to 7.6) versus 3.0 (1.2 to 5.3) years for the control group. Mean scores were compared to a cohort of uncomplicated total knee arthroplasties matched by age, body mass index, and sex using generalized linear models adjusted for follow-up duration. Kaplan-Meier survivorship curves for PJI were constructed. RESULTS: Mean Patient Reported Outcome Scores for the DAIR cohort were 57.2 ± 19.7 for KOOS-JR, 41.6 ± 7.1 for PROMIS physical health (PH), and 46.6 ± 8.7 for PROMIS mental health (MH). Mean control group values were 65.8 ± 21.0 for KOOS-JR, 44.6 ± 8.4 for PROMIS PH, and 49.2 ± 9.2 for PROMIS MH. No difference was observed in KOOS-JR (P = .83) or PROMIS MH (P = .11). PROMIS PH was lower in the DAIR cohort compared to the control group (P = .048). Median follow-up (years) for all 191 cases was 5.9 (range, 0.5 to 13.1). Survivorship (years) without subsequent operation for infection was 84% at 1, 82% at 2, and 79% at 5. CONCLUSION: Knee and MH outcomes in successful DAIR procedures were similar to uncomplicated total knee arthroplasty. DAIR's success rate was 79% in treating acute PJI at 5 years. LEVEL OF EVIDENCE: Level III.

Altered Ulnar Variance With Full-Body Weight-bearing During Handstands With Upper Extremity Weight-bearing CT.

PURPOSE: Ulnar variance (UV) is a radiographic measurement relating the articular surface heights of the distal radius and ulna. Abnormal UV increases the risk for wrist pathology; however, it only provides a static measurement of an inherently dynamic bony relationship that changes with wrist position and loading. The purpose of this study was to investigate how full-body weight-bearing affects UV using weight-bearing computed tomography (WBCT). METHODS: Ten gymnasts completed two 45-second scans inside a WBCT machine while performing a handstand on a flat platform (H) and parallettes (P). A non-weight-bearing CT scan was collected to match clinical practice (N). Differences in UV between weight-bearing conditions were evaluated separately for dominant and nondominant sides, and then, UV was compared between weight-bearing conditions on pooled dominant/nondominant data. RESULTS: Pooled analyses comparing weight-bearing conditions revealed a significant increase in UV for H versus N (0.58 mm) and P versus N (1.00 mm), but no significant change in UV for H versus P (0.43 mm). Significant differences in UV were detected for H versus N, P versus N, and H versus P for dominant and nondominant extremities. The change from N to H was significantly greater in the dominant versus nondominant side, but greater in the nondominant side from N to P. CONCLUSIONS: Ulnar variance changed with the application of load and position of the wrist. Differences in UV were found between dominant and nondominant extremities. CLINICAL RELEVANCE: Upper extremity loading patterns are affected by hand dominance as defined by a cartwheel and suggest skeletal consequences from repetitive load on a dominantly used wrist. Although statistically significant, subtle changes detected in this investigational study do not necessarily bear clinical significance. Future WBCT research can lead to improved diagnostic measures for wrist pathologies affected by active loading and rotational wrist behavior.

What is the Impact of Social Deprivation on Mental and Physical Health Before and After Primary Total Knee Arthroplasty?

Background: The purpose of the present study was to investigate the relationship between socioeconomic status and Patient-Reported Outcomes Measurement Information System Global Health (PROMIS-GH) scores before and after primary total knee arthroplasty (TKA). We hypothesized that patients with greater social deprivation would have lower PROMIS-GH scores at 3 months and 1 year following primary TKA. Methods: We retrospectively reviewed data from patients who underwent unilateral primary TKA and completed PROMIS-GH preoperatively and at 3 months (n = 257) or 1 year (n = 154) postoperatively. Area Deprivation Index (ADI), calculated from 9-digit zip codes, was used to measure social deprivation. Participants were grouped into quartiles by ADI score. Minimal clinically important difference in PROMIS-GH mental (PROMIS-MH) and physical health (PROMIS-PH) component scores were compared between ADI groups. Results: Participants in the highest ADI quartile (most disadvantaged) had significantly lower PROMIS-MH and PROMIS-PH scores at every time point relative to the lowest ADI quartile (least disadvantaged) (P < .05 for all). Both ADI groups experienced significant improvements in PROMIS-PH following TKA (P < .001 for all), but not in PROMIS-MH (P > .05 for all) at 3-months and 1-year postoperatively. Magnitude of improvement in PROMIS-PH and rates of achievement of minimal clinically important difference did not significantly differ between ADI groups (P > .05 for all). Conclusions: Socially disadvantaged patients benefit equally from primary TKA but are more likely to have persistently lower 1-year postoperative PROMIS-GH scores relative to less disadvantaged patients. Social deprivation should be accounted for when using PROMIS-GH to assess clinical outcomes for research and quality measures. Level of Evidence: IV, retrospective cohort study.

Projected Prevalence of Obesity in Aseptic Revision Total Hip and Knee Arthroplasty.

Background: The purpose of this study was to develop projections of the prevalence of obesity in aseptic revision THA and TKA patients through the year 2029. Methods: The National Surgical Quality Improvement Project (NSQIP) was queried for years 2011-2019. Current procedural terminology (CPT) codes 27134, 27137, and 27138 were used to identify revision THA and CPT codes 27486 and 27487 were used to identify revision TKA. Revision THA/TKA for infectious, traumatic, or oncologic indications were excluded. Participant data were grouped according to body mass index (BMI) categories: underweight/normal weight, <25 kg/m2; overweight, 25-29.9 kg/m2; class I obesity, 30.034.9 kg/m2; class II obesity, 35.0-39.9 kg/m2; morbid obesity ≥ 40 kg/m2. Prevalence of each BMI category was estimated from year 2020 to year 2029 through multinomial regression analyses. Results: 38,325 cases were included (16,153 revision THA and 22,172 revision TKA). From 2011 to 2029, prevalence of class I obesity (24% to 25%), class II obesity (11% to 15%), and morbid obesity (7% to 9%) increased amongst aseptic revision THA patients. Similarly, prevalence of class I obesity (28% to 30%), class II obesity (17% to 29%), and morbid obesity (16% to 18%) increased in aseptic revision TKA patients. Conclusion: Prevalence of class II obesity and morbid obesity demonstrated the largest increases in revision TKA and THA patients. By 2029, we estimate that approximately 49% of aseptic revision THA and 77% of aseptic revision TKA will have obesity and/or morbid obesity. Resources aimed at mitigating complications in this patient population are needed. Level of Evidence: III.

Food Insecurity Is Common in the Orthopedic Trauma Population at a Rural Academic Trauma Center.

Background: Food insecurity is an increasingly recognized public health issue. Identifying risk factors for food insecurity would support public health initiatives to provide targeted nutrition interventions to high-risk individuals. Food insecurity has not been investigated in the orthopedic trauma population. Methods: From April 27, 2021 to June 23, 2021, we surveyed patients within six months of operative pelvic and/or extremity fracture fixation at a single institution. Food insecurity was assessed using the validated United States Department of Agriculture Household Food Insecurity questionnaire generating a food security score of 0 to 10. Patients with a food security score ≥ 3 were classified as Food Insecure (FI) and patients with a food security score < 3 were classified as Food Secure (FS). Patients also completed surveys for demographic information and food consumption. Differences between FI and FS for continuous and categorical variables were evaluated using the Wilcoxon sum rank test and Fisher's exact test, respectively. Spearman's correlation was used to describe the relationship between food security score and participant characteristics. Logistic regression was used to determine the relationship between patient demographics and odds of FI. Results: We enrolled 158 patients (48% female) with a mean age of 45.5 ± 20.3 years. Twenty-one patients (13.3%) screened positive for food insecurity (High security: n=124, 78.5%; Marginal security: n=13, 8.2%; Low security: n=12, 7.6%; Very Low security: n=9, 5.7%). Those with a household income level of ≤ $15,000 were 5.7 times more likely to be FI (95% CI 1.8-18.1). Widowed/single/divorced patients were 10.2 times more likely to be FI (95% CI 2.3-45.6). Median time to the nearest full-service grocery store was significantly longer for FI patients (t=10 minutes) than for FS patients (t=7 minutes, p=0.0202). Age (r= -0.08, p=0.327) and hours working (r= -0.10, p=0.429) demonstrated weak to no correlation with food security score. Conclusion: Food insecurity is common in the orthopedic trauma population at our rural academic trauma center. Those with lower household income and those living alone are more likely to be FI. Multicenter studies are warranted to evaluate the incidence and risk factors for food insecurity in a more diverse trauma population and to better understand its impact on patient outcomes. Level of Evidence: III.

Unicompartmental Knee Arthroplasty Utilization among Early Career Surgeons: An Evaluation of the American Board of Orthopaedic Surgery Part-II Database.

An updated understanding of unicompartmental knee arthroplasty (UKA) utilization is needed. The purpose of this study was to evaluate temporal trends in volume and utilization of UKA among early-career surgeons and to examine the influence of fellowship training status on utilization of UKA. The American Board of Orthopaedic Surgery (ABOS) Part-II database was queried from 2010 to 2019 to identify candidates who reported ≥1 total knee arthroplasty (TKA) or UKA. Self-reported history of fellowship training experiences was recorded. "High-volume" surgeons were defined as performing ≥7 UKA over the ABOS Part-II collection period. Trends were evaluated with the Cochrane-Armitage test and generalized linear models. From 2010 to 2019, a total of 2,045 candidates (28.1%) reported ≥1 TKA, while 585 candidates (8.0%) reported ≥1 UKA. The number of candidates reporting ≥1 UKA significantly increased (p = 0.001). An increase in UKA volume was observed over the study period (p < 0.001). Rates of utilization of UKA relative to TKA did not change significantly over the study period (p = 0.11). Sixty-three (2.4%) candidates met the study definition for high-volume UKA utilization. UKA procedure volume increased among ABOS Part-II candidates over the study period; however, rates of UKA utilization relative to TKA volume remained unchanged. Increasing volume of UKA performed by early-career surgeons is likely secondary to an increased number of surgeons trained in adult reconstruction. Only 2.4% of candidates who reported performing at least one knee arthroplasty procedure met the threshold for a high-volume UKA practice. Early-career surgeons should remain conscientious of UKA volume in their practice.

A Novel Prescription Method Reduces Postoperative Opioid Distribution and Consumption: A Randomized Clinical Trial.

BACKGROUND: Prescription opioid abuse in the United States has risen substantially over the past 2 decades. Narcotic prescription refill restrictions may paradoxically be contributing to this epidemic. We investigated a novel, refill-based opioid prescription method to determine whether it would alter postoperative narcotic distribution or consumption. METHODS: In this randomized controlled trial, patients undergoing internal fixation of distal radius fractures or thumb carpometacarpal joint arthroplasty received either a single prescription for all postoperative narcotics (control arm) or the same amount of pain medication divided into 3 equal prescriptions to be filled as needed (experimental arm). Outcomes included total narcotics dispensed, measured in morphine milligram equivalents (MME) through a prescription monitoring program, patient-reported opioid consumption versus opioid not consumed, and a satisfaction survey. RESULTS: Forty-eight participants were enrolled; 25 were randomized to the control arm and 23 to the experimental arm. At 8 weeks post-op, fewer opioids had been dispensed to the experimental arm (177 ± 94 vs 287 ± 123 MME, P = .0025). At 6-week follow-up, the experimental arm reported lower narcotic consumption (124 ± 105 vs 214 ± 110 MME, P = .0131). Subanalysis of the independent surgeries yielded similar results. Some patients reported insurance issues when filling subsequent prescriptions. Consequently, although 100% of control arm patients reported good pain control, only 82.6% of experimental arm patients said likewise (P = .0455). CONCLUSIONS: This randomized clinical trial demonstrated that patients obtained and consumed fewer narcotics when postoperative opioids were given in a refill-based prescription method. More research is needed to determine whether this opioid distribution method is reproducible, translatable, and feasible.

Did Rapid Expansion of Same Day Discharge Hip and Knee Arthroplasty During the COVID-19 Pandemic Increase Early Complications?

Background: The COVID-19 pandemic has had a lasting impact on patients seeking total hip and knee arthroplasty (THA, TKA) including more patients undergoing same day discharge (SDD) following total joint arthroplasty (TJA). The purpose of this study was to assess whether expansion of SDD TJA during the COVID-19 pandemic resulted in more early complications following TJA. We anticipated that as many institutions quickly launched SDD TJA programs there may be an increase in 30-day complications. Methods: We retrospectively queried the ACS-NSQIP database for all patients undergoing primary elective TJA from January 1, 2018, to December 31, 2020. Participants who underwent THA or TKA between January 1, 2018 and March 1, 2020 were grouped into pre-COVID and between March 1, 2020 and December 31, 2020 were grouped into post-COVID categories. Patients with length of stay greater than 0 were excluded. Primary outcome was any complication at 30 days. Secondary outcomes included readmission and re-operation 30 days. Results: A total of 14,438 patients underwent TKA, with 9,580 occurring pre-COVID and 4,858 post-COVID. There was no difference in rates of total complication between the pre-COVID (3.55%) and post-COVID (3.99%) groups (p=0.197). Rates of readmissions for were similar for the pre-COVID (1.75%) and post-COVID (1.98%) groups (p=0.381). There was no statistically significant difference in respiratory complications between the pre-COVID (0.41%) and post-COVID group (0.23%, p=0.03). A total of 12,265 patients underwent THA, with 7,680 occurring pre-COVID and 4,585 post-COVID. There was no difference in rates of total complication between the pre-COVID (3.25%) and post-COVID (3.49%) groups (p=0.52). Rates of readmissions for were similar for the pre-COVID (1.77%) and post-COVID (1.68%) groups (p=0.381). There was no statistically significant difference in respiratory complications between the pre-COVID (0.16%) and post-COVID group (0.07%, p=0.26). Combined data to include THA and TKA patients did not find a statistical difference in the rate of complications or readmission but did note a decrease in the rate of combined respiratory complications in the post-COVID group (0.15% vs. 0.30%, p=0.028). Conclusion: Rapid expansion of SDD TJA during the COVID-19 pandemic did not increase overall complication, readmission, or re-operation rates. Level of Evidence: IV.

Does preoperative gabapentin or intraoperative ketorolac influence postoperative pain following hip arthroscopy?

Optimization of perioperative analgesia has important implications for patient satisfaction and short-term outcomes. This study's purpose is to assess if preoperative gabapentin or intraoperative ketorolac influences postoperative pain or time to discharge following hip arthroscopy. In total, 409 patients who underwent hip arthroscopic femoroplasty and/or acetabuloplasty with a single surgeon for femoroacetabular impingement were retrospectively reviewed (September 2017 to February 2021). The effect of preoperative gabapentin or intraoperative ketorolac on postoperative visual analog scale (VAS) pain scores, perioperative opioids in morphine milligram equivalents (MMEs), time in post-anesthesia care unit (PACU), second-stage recovery and time to discharge was assessed using unadjusted and adjusted t-tests, and generalized linear models controlling for operative time, traction time, preoperative MME, intraoperative MME and postoperative MME were compared between the groups of gabapentin to no gabapentin and ketorolac to no ketorolac. There was no difference in first PACU VAS pain score, final PACU VAS score, VAS pain score prior to discharge, average VAS pain score or pain level on follow-up call in the unadjusted or adjusted analysis for the preoperative gabapentin or intraoperative ketorolac groups. Females had higher first PACU VAS pain score (6.05 versus 5.15 P = 0.0026), final PACU VAS pain score (4.43 versus 3.90, P = 0.0045), final VAS pain score prior to discharge (3.87 versus 3.03, P < 0.001) and average postoperative pain score (4.60 versus 4.03, P < 0.001), but no difference in VAS pain score on follow-up call following surgery. Gabapentin or ketorolac was not associated with decreased VAS pain scores or time to discharge after hip arthroscopy.

Does Isolated Unilateral Hip or Knee Osteoarthritis Lead to Adverse Changes in Extremity Composition?

Background: While muscle atrophy is a function of normal aging, loss of muscle in the setting of hip and knee osteoarthritis (OA) has been observed using radiographic studies. There is limited data available regarding changes in extremity composition using bioimpedance (BIA). The purpose of this study was to assess the changes in extremity composition in patients with isolated, unilateral hip or knee OA using BIA. Methods: Patients presenting to our institution's adult reconstruction clinic from February 2020 to April 2021 were retrospectively reviewed to identify those with isolated, unilateral hip and knee OA. The InBody 770 Body Composition Analyzer (InBody USA, Cerritos, California) was used to perform a complete body composition assessment, per protocol. Lean extremity mass (LEM), fat mass (FM), intracellular water (ICW), extremity body water (EBW = ICW + extracellular water (ECW)) and phase angle (PA) were determined. Differences between the affected (OA) and unaffected (no OA) extremities were compared using t-tests. Results: 38 patients had isolated hip OA. The mean age was 60.8 (±11.7) years, mean BMI was 31.7 (±6.8) kg/m2, and 39.5% were female. LEM, FM, EBW, ICW, and PA were significantly decreased in the hip OA extremity (LEM: 20.0 vs. 20.4 kg, p=0.0008, FM: 8.8 vs. 8.9 kg, p=0.0049, EBW: 15.7 vs 16.0, p=0.0011, ICW: 9.5 vs. 9.7 L, p=0.0004, PA: 4.5 vs 4.9º, p<0.0001). There were 25 patients with isolated knee OA. Mean age was 62.8 (±11.3) years, mean BMI was 33.6 (±6.9) kg/m2, and 52.0% were female. FM and PA were significantly lower in the knee OA extremity (11.3 vs 11.4 kg, p=0.0291, 4.5 vs 4.9º, p<0.0001). There were no significant differences in LEM, EBW, and ICW between the knee OA extremity and the unaffected extremity. Conclusion: Patients with isolated, unilateral hip OA had decreased LEM, FM, EBW, and ICW in the affected extremity. Both unilateral hip and knee OA was associated with decreased PA, suggestive of greater underlying dysfunction in muscle or cellular performance. Further study is needed to better define when these abnormalities develop, how they progress over time, and the impact of targeted interventions in reversing these changes. Level of Evidence: III.

Reliability of Multifrequency Bioelectrical Impedance Analysis to Quantify Body Composition in Patients After Musculoskeletal Trauma.

Background: Changes in body composition, especially loss of lean mass, commonly occur in the orthopedic trauma population due to physical inactivity and inadequate nutrition. The purpose of this study was to assess inter-rater and intra-rater reliability of a portable bioelectrical impedance analysis (BIA) device to measure body composition in an orthopedic trauma population after operative fracture fixation. BIA uses a weak electric current to measure impedance (resistance) in the body and uses this to calculate the components of body composition using extensively studied formulas. Methods: Twenty subjects were enrolled, up to 72 hours after operative fixation of musculoskeletal injuries and underwent body composition measurements by two independent raters. One measurement was obtained by each rater at the time of enrollment and again between 1-4 hours after the initial measurement. Reliability was assessed using intraclass correlation coefficients (ICC) and minimum detectable change (MDC) values were calculated from these results. Results: Inter-rater reliability was excellent with ICC values for body fat mass (BFM), lean body mass (LBM), skeletal muscle mass (SMM), dry lean mass (DLM), and percent body fat (PBF) of 0.993, 0.984, 0.984, 0.979, and 0.986 respectively. Intra-rater reliability was also high for BFM, LBM, SMM, DLM, and PBF, at 0.994, 0.989, 0.990, 0.983, 0.987 (rater 1) and 0.994, 0.988, 0.989, 0.985, 0.989 (rater 2). MDC values were calculated to be 4.05 kg for BFM, 4.10 kg for LBM, 2.45 kg for SMM, 1.21 kg for DLM, and 4.83% for PBF. Conclusion: Portable BIA devices are a versatile and attractive option that can reliably be used to assess body composition and changes in lean body mass in the orthopedic trauma population for both research and clinical endeavors. Level of Evidence: III.

Operative Time and Risk of Surgical Site Infection and Periprosthetic Joint Infection: A Systematic Review and Meta-Analysis.

Background: The purpose of this study was to perform a systematic review and meta-analysis on the association between operative time and peri-prosthetic joint infection (PJI) after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). Methods: PubMed, Embase, and Cochrane CENTRAL databases were searched for relevant articles dating 2000-2020. Relationship of operative time and PJI rate in primary total joint arthroplasty (TJA) was evaluated by pooled odds ratios (OR) and 95% confidence intervals. Results: Six studies were identified for meta-analysis. TJA lasting greater than 120 minutes had greater odds of PJI (OR, 1.63 [1.00-2.66], p=0.048). Similarly, there were greater odds of PJI for TJA procedures lasting greater than 90 minutes (OR, 1.65 [1.27-2.14]; p<0.001). Separate analyses of TKA (OR, 2.01 [0.76-5.30]) and THA (OR, 1.06 [0.80-1.39]) demonstrated no difference in rates of PJI in cases of operative time ≥ 120 minutes versus cases < 120 minutes (p>0.05 for all). Using any surgical site infection (SSI) as an endpoint, both TJA (OR, 1.47 [1.181.83], p<0.001) and TKA (OR, 1.50 [1.08-2.08]; p=0.016) procedures lasting more versus less than 120 minutes demonstrated significantly higher odds of SSI. Conclusion: Following TJA, rates of SSI and PJI are significantly greater in procedures ≥120 minutes in duration relative to those < 120 minutes. When analyzing TKA separately, higher rates of SSI were observed in procedures ≥ 120 minutes in duration relative to those <120 minutes. Rates of PJI in TKA or THA procedures alone were not significantly impacted by operative time. Level of Evidence: V.

FEAR index in predicting treatment among patients with femoroacetabular impingement and hip dysplasia and the relationship of femoral version.

The Femoro-Epiphyseal Acetabular Roof (FEAR) index is a newer measurement to identify the hip instability with borderline acetabular dysplasia. The purpose of this study is to (i) validate the FEAR index in determining the stability of the hip in patients who have previously been treated surgically for femoroacetabular impingement (FAI) and/or developmental dysplasia of the hip (DDH) and (ii) to examine the relationship between the FEAR index and femoral version, lateral center edge angle, Tönnis angle and alpha angle (AA). Patient demographics and radiographic measurements of 215 hips (178 patients), 116 hips treated with hip arthroscopy for FAI and 99 hips treated with periacetabular osteotomy (PAO) for DDH were compared between groups. The sensitivity and specificity of the FEAR index to detect the surgical procedure performed (PAO or hip arthroscopy) was calculated, and a threshold value was proposed. Pearson's correlation coefficients were used to describe the relationships between the FEAR index, femoral version and other radiographic measurements. The FEAR index was higher in patients with DDH versus FAI (DDH: 2.81 ± 0.50° versus FAI: -1.00 ± 0.21°, P < 0.001). A FEAR index threshold value of 3° had a sensitivity and specificity of 80% and 81%, respectively, for correctly predicting the surgical procedure performed. Femoral version was positively associated with the FEAR index in the setting of DDH (r = 0.36, P = 0.001) but not FAI (r = 0.02, P = 0.807). A FEAR index of 3° predicted treatment with 80% sensitivity and 81% specificity. In addition, femoral version significantly correlates with the FEAR index in the setting of DDH but not FAI.

Comparison of Patient-Reported Outcomes and Functional Assessment Using a Marker-Less Image Capture System in End-Stage Knee Arthritis.

BACKGROUND: Patient self-assessment of knee function in end-stage osteoarthritis (OA) and following total knee arthroplasty (TKA) using patient-reported outcome measures (PROMs) has become standard for defining disability. The relationship of PROMs to functional performance requires a continued investigation. The purpose of this study was to determine correlations between patient demographics, PROMs, and functional performances using a marker-less image capture system (MICS). METHODS: Patients indicated for elective TKA completed the Knee Injury and Osteoarthritis Score for Joint Replacement (KOOS-JR) and an office-based functional assessment using a MICS. Patient age, body mass index (BMI), and gender were collected. A total of 112 patients were enrolled. Their mean age was 65.0 (±9.7) years, mean BMI was 32.5 (±6.6) kg/m2, and mean KOOS-JR was 14.5 (±5.7). The relationships between patient characteristics, KOOS-JR, MICS Alignment (coronal), MICS Mobility (flexion), and composite Total Joint scores were described using Spearman's correlation coefficients. RESULTS: BMI was weakly correlated with KOOS-JR (ρ = -0.22, P = .024), whereas age was not. Age and BMI were not correlated with performance scores. There were weak to no correlations between KOOS-JR and MICS Alignment (ρ = -0.01, P = .951), Mobility (ρ = 0.33, P < .001), and Total Joint scores (ρ = 0.06, P = .504). CONCLUSION: This study found no strong correlation between KOOS-JR and functional performance using a validated MICS for patients with end-stage knee OA. Further study is warranted in determining the relationship between PROMs and performance to optimize outcomes of patients undergoing nonoperative or surgical interventions for knee OA. The use of high-fidelity functional assessment tools that can be integrated into clinical workflow, such as the MICS used in this study, should permit PROM/functional performance comparisons in large populations.

Prevalence of Sarcopenia and Sarcopenic Obesity in an Academic Total Joint Arthroplasty Practice.

Background: Body mass index (BMI) is routinely used for preoperative risk stratification; however, it does not provide a detailed assessment of body composition and intentional weight loss alone may not decrease complications. Sarcopenia-a disorder involving low muscle mass, quality, or performance-has been associated with an increased risk for postoperative complications and is treatable through nutritional supplementation or resistance training. It, counterintuitively, may occur with obesity as "sarcopenic obesity"; however, the prevalence is not widely known. The purpose of this study was to assess the prevalence of sarcopenia and sarcopenic obesity. Material and methods: Patients underwent body composition assessment using multifrequency bioimpedance testing (InBody 770, InBody USA, California). They were classified as sarcopenic based on the appendicular skeletal muscle index and obese by percent body fat. Body composition parameters were compared between obesity or sarcopenia groups and traditional BMI-based obesity definitions. Results: A total of 219 patients underwent body composition assessment. The mean age was 62.1 years, BMI was 34.3 kg/m2, and 53.8% were female. Fifty-seven (26.0%) patients were not obese or sarcopenic, 130 (59.4%) were obese not sarcopenic, 18 (8.2%) were sarcopenic nonobese, and 14 (6.4%) were sarcopenic obese. There was heterogeneity in body composition between groups. Sarcopenic patients were older than those without sarcopenia. Skeletal muscle mass, body fat mass, and appendicular skeletal muscle index increased with increasing BMI. Conclusion: Sarcopenia and sarcopenic obesity were found in nearly 15% of patients. Measures of muscle quantity increased with higher BMI may influence the prevalence of sarcopenia in the morbidly obese, and these patients may require specialized criteria accounting for increased body mass.

Conditionally Essential Amino Acid Supplementation Reduces Postoperative Complications and Muscle Wasting After Fracture Fixation: A Randomized Controlled Trial.

BACKGROUND: Postoperative complications and substantial loss of physical function are common after musculoskeletal trauma. We conducted a prospective randomized controlled trial to assess the impact of conditionally essential amino acid (CEAA) supplementation on complications and skeletal muscle mass in adults after operative fixation of acute fractures. METHODS: Adults who sustained pelvic and extremity fractures that were indicated for operative fixation at a level-I trauma center were enrolled. The subjects were stratified based on injury characteristics (open fractures and/or polytrauma, fragility fractures, isolated injuries) and randomized to standard nutrition (control group) or oral CEAA supplementation twice daily for 2 weeks. Body composition (fat-free mass [FFM]) was measured at baseline and at 6 and 12 weeks postoperatively. Complications were prospectively collected. An intention-to-treat analysis was performed. The relative risk (RR) of complications for the control group relative to the CEAA group was determined, and linear mixed-effects models were used to model the relationship between CEAA supplementation and changes in FFM. RESULTS: Four hundred subjects (control group: 200; CEAA group: 200) were enrolled. The CEAA group had significantly lower overall complications than the control group (30.5% vs. 43.8%; adjusted RR = 0.71; 95% confidence interval [CI] = 0.55 to 0.92; p = 0.008). The FFM decreased significantly at 6 weeks in the control subjects (-0.9 kg, p = 0.0205), whereas the FFM was maintained at 6 weeks in the CEAA subjects (-0.33 kg, p = 0.3606). This difference in FFM was not seen at subsequent time points. CONCLUSIONS: Our results indicate that CEAA supplementation has a protective effect against common complications and early skeletal muscle wasting after operative fixation of extremity and pelvic fractures. Given the potential benefits of this inexpensive, low-risk intervention, multicenter prospective studies in focused trauma populations are warranted. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Projected Prevalence of Obesity in Primary Total Knee Arthroplasty: How Big Will the Problem Get?

BACKGROUND: Obesity is a well-established risk factor for complications following primary total knee arthroplasty (TKA). The purpose of this study is to utilize 3 national databases to develop projections of obesity within the general population and primary TKA patients in the United States through 2029. METHODS: Data from the National Surgical Quality Improvement Program (NSQIP), the Behavior Risk Factor Surveillance System (BRFSS), and the National Health and Nutrition Examination Survey were queried for years 1999-2019. Current Procedural Terminology code 27447 was used to identify primary TKA patients in NSQIP. Individuals were categorized according to body mass index (kg/m2) by year: normal weight (≤24.9); overweight (25.0-29.9); obese (30.0-39.9); and morbidly obese (≥40). Multinomial logistic regression was used to project categorical body mass index data for years 2020-2029. RESULTS: A total of 8,372,221 individuals were included (7,986,414 BRFSS, 385,807 NSQIP TKA). From 2011 to 2019, the prevalence of normal weight and overweight individuals declined in the general population (BRFSS) and in primary TKA. Prevalence of obese/morbidly obese individuals increased in the general population from 31% to 36% and in primary TKA from 60% to 64%. Projection models estimate that by 2029, 46% of the general population will be obese/morbidly obese and 69% of primary TKA will be obese/morbidly obese. CONCLUSION: By 2029, we estimate ≥69% of primary TKA to be obese/morbidly obese. Increased resources dedicated to care pathways and research focused on improving outcomes in obese arthroplasty patients will be necessary as this population continues to grow. LEVEL OF EVIDENCE: Level III, Retrospective Cohort Study.

Not all Total Hip and Knee Arthroplasties Are the Same: What Are the Implications in Large Database Studies?

BACKGROUND: The use of claims databases for research after total hip and knee arthroplasty (THA, TKA) has increased exponentially. These studies rely on accurate coding, and inadvertent inclusion of patients with nonroutine indications may influence results. The purpose of this study was to evaluate the complexity of THA and TKA captured by CPT code and determine if complication rates vary based on the indication. METHODS: The NSQIP database was queried using CPT codes 21730 and 27447 to identify patients undergoing THA and TKA from 2018 to 2019. The surgical indication was classified based on the ICD-10 diagnosis code as routine primary, complex primary, inflammatory, fracture, oncologic, revision, infection, or indeterminant. Patient factors and 30-day complications, readmission, reoperation, and wound complications were compared. RESULTS: A total of 86,009 THA patients had 703 ICD-10 diagnosis codes and 91.4% were routine primary indications. Complication rates were: routine primary 7.4%, complex primary 11.3%, inflammatory 12.5%, fracture 23.9%, oncologic 32.4%, revision 26.9%, infection 38.7%, and indeterminant 10.3% (P < .0001). 137,500 TKA patients had 552 ICD-10 diagnosis codes and 96.1% were routine primary cases. Complication rates were: routine primary 5.9%, complex primary 8.0%, inflammatory 7.2%, fracture 38.9%, oncologic 32.7%, revision 13.3%, infection 37.7%, and indeterminant 9.6% (P < .0001). Routine primary arthroplasty had significantly lower rates of reoperation, readmission, and wound complications. CONCLUSION: Using CPT code alone captures 10% of THA and 4% of TKA patients with procedures for nonroutine primary indications. It is essential to recognize identification of patients simply by CPT code has the potential to inadvertently introduce bias, and surgeons should critically assess methods used to define the study populations.

What Is the Impact of Body Mass Index Cutoffs on Total Hip Arthroplasty Complications?

BACKGROUND: Body mass index (BMI) cutoffs are commonly utilized to decide whether to offer obese patients elective total hip arthroplasty (THA). However, weight loss goals may be unachievable for many, and some patients are thereby denied complication-free surgery. The purpose of this study was to assess the impact of varying BMI cutoffs on the rates of complication-free surgery after THA. METHODS: Patients undergoing THA between 2015 and 2018 were identified in the American College of Surgeons National Surgical Quality Improvement Program database using Common Procedural Terminology code 27130. BMI and rates of 30-day complications were collected. BMI cutoffs of 30, 35, 40, 45, and 50 kg/m2 were applied to model the incidence of complications if THA would have been allowed to proceed based on BMI. RESULTS: A total of 192,394 patients underwent THA, and 13,970 (7%) of them had a BMI ≥40 kg/m2. With a BMI cutoff of 40 kg/m2, 178,424 (92.7%) patients would have proceeded with THA. From this set, 170,296 (95.4%) would experience complication-free surgery, and 11.8% of complications would be prevented. THA would proceed for 191,217 (99.3%) patients at a BMI cutoff of 50 kg/m2, of which 182,123 (95.2%) would not experience a complication, and 1.3% of complications would be prevented. Using 35 kg/m2 as the BMI cutoff would prevent 28.6% of complications and permit 75.9% of complication-free surgeries to proceed. CONCLUSION: Lower BMI cutoffs for THA can result in fewer complications although they will consequentially limit access to complication-free THA. Consideration of risks of obesity in THA may be best considered as part of a holistic assessment and shared decision-making when deciding on goals for weight reduction.