Impact of comorbid conditions on outcomes of hip and knee replacement surgery: a systematic review and meta-analysis

Prediction of implant failure risk due to periprosthetic femoral fracture after primary elective total hip arthroplasty : a simplified and validated model based on 154,519 total hip arthroplasties from the Swedish Arthroplasty Register

Aims

While cementless fixation offers potential advantages over cemented fixation, such as a shorter operating time, concerns linger over its higher cost and increased risk of periprosthetic fractures. If the risk of fracture can be forecasted, it would aid the shared decision-making process related to cementless stems. Our study aimed to develop and validate predictive models of periprosthetic femoral fracture (PPFF) necessitating revision and reoperation after elective total hip arthroplasty (THA).

Methods

We included 154,519 primary elective THAs from the Swedish Arthroplasty Register (SAR), encompassing 21 patient-, surgical-, and implant-specific features, for model derivation and validation in predicting 30-day, 60-day, 90-day, and one-year revision and reoperation due to PPFF. Model performance was tested using the area under the curve (AUC), and feature importance was identified in the best-performing algorithm.

Results

The Lasso regression excelled in predicting 30-day revisions (area under the receiver operating characteristic curve (AUC) = 0.85), while the Gradient Boosting Machine (GBM) model outperformed other models by a slight margin for all remaining endpoints (AUC range: 0.79 to 0.86). Predictive factors for revision and reoperation were identified, with patient features such as increasing age, higher American Society of Anesthesiologists grade (> III), and World Health Organization obesity classes II to III associated with elevated risks. A preoperative diagnosis of idiopathic necrosis increased revision risk. Concerning implant design, factors such as cementless femoral fixation, reverse-hybrid fixation, hip resurfacing, and small (< 35 mm) or large (> 52 mm) femoral heads increased both revision and reoperation risks.

Conclusion

This is the first study to develop machine-learning models to forecast the risk of PPFF necessitating secondary surgery. Future studies are required to externally validate our algorithm and assess its applicability in clinical practice.

Outpatient Total Joint Arthroplasty in the "Unhealthy": Staying Safe Using Institutional Protocols

BACKGROUND

Recent expansion in the indications for outpatient total joint arthroplasty has led to debates over patient selection. The purpose of this study was to compare early clinical outcomes and complications of same-day discharge (SDD) hip and knee arthroplasties from a high-volume institution based on the American Society of Anesthesiologists (ASA) physical status classification.

METHODS

Prospectively collected data were reviewed for all SDD primary joint arthroplasties between January 2013 and August 2023. There were 8 surgeons who performed 7,258 cases at hospital outpatient (n = 4,288) or ambulatory surgery centers (n = 2,970). This included 3,239 total hip arthroplasties, 1,503 total knee arthroplasties, and 2,516 unicompartmental knee arthroplasties. The ASA 1 group comprised 506 subjects, compared to 5,005 for ASA 2 and 1,736 for ASA 3. The primary outcomes included emergency department (ED) visits, readmissions, complications, and revisions within 24 hours and 90 days of surgery. The ASA 3 group was older (ASA 1 = 55 versus ASA 2 = 63 versus ASA 3 = 66 years; P < .01) and had a higher body mass index (ASA 1 = 25.4 versus ASA 2 = 28.5 versus ASA 3 = 32.7; P < .01).

RESULTS

There were no differences between ASA groups in joint-related ED visits, readmissions, and complications within 24 h and 90 days of surgery (P > .05). Subjects in the ASA 3 group experienced greater 90-day revisions compared to the other groups (ASA 1 = 1 of 506, 0.2% versus ASA 2 = 15 of 5,005, 0.3% versus ASA 3 = 15 of 1,736, 0.9%; P = .01). Regarding systemic events, ASA 1 subjects experienced significantly greater 24-hour complications (8 of 506, 1.6%) and ED visits (5 of 506, 1.0%), and the ASA 3 subjects had a higher incidence of 90-day readmissions (19 of 1,736, 1.1%) compared to the other groups (P < .05). Within 24 hours of discharge, urinary retention and syncope were the most frequent complications that required additional health care utilization.

CONCLUSIONS

Medically optimized patients categorized as ASA 3 can safely undergo SDD hip and knee arthroplasty without increased risk of 24-hour or 90-day complications. Patient preference for outpatient care, reliable social support, and independent functional status are imperative for a successful outpatient program.

Does admission to intensive care post total joint arthroplasty result in poorer outcomes 12-months after surgery?

BACKGROUND

It is unknown if total joint arthroplasty (TJA) patients admitted to the intensive care unit (ICU) benefit from the surgery. This impedes clinical decision-making, resource allocation and patient informed consent. This study aims to identify whether admission to ICU post-TJA surgery is associated with poorer quality of life, pain and function, compared to those not requiring ICU admission.

METHODS

Data on patients who underwent elective total hip or knee arthroplasty between 2006 and 2019 were extracted from a single-institution registry in Melbourne, Australia. Adjusted mixed-linear regression models were used to estimate the mean difference at 12 months in quality of life (VR-12), and pain and function (WOMAC) between patients admitted postoperatively to ICU and those not admitted.

RESULTS

Of the 8444 patients that met the study inclusion criteria, 128 (1.5%) patients were admitted to ICU peri- or postoperatively. The median length of stay in ICU was 1 day (IQR = 1). Patients in both groups reported similar clinically meaningful improvements in quality of life, pain and function 12-months after surgery.

CONCLUSION

Clinicians weighing up risks versus benefits of TJA in patients with a higher risk of ICU admission should not overlook the significant improvements in quality of life, pain and function likely to be seen.

Effect of co-morbidities on outcomes of first metatarsophalangeal joint fusion: A systematic review

Introduction

The pre-existing co-morbidities have a major impact on the outcomes of Orthopaedic procedures as shown by the several studied in various contexts. However, the specific influence of these co-morbidities on first metatarsophalangeal joint fusion remains relatively underexplored. This study aims to address this gap by examining the association between co-morbidities such as obesity, smoking, diabetes, advancing age, and rheumatoid arthritis, and the outcomes of first metatarsophalangeal joint fusion.

Methods

A comprehensive search was conducted across multiple databases, including MEDLINE, EMBASE, and CINAHL. Relevant articles were identified and processed using Covidence, with independent assessment conducted to ensure inclusion criteria were met. The focus of the review was on analysing the effects of specific co-morbidities on fusion outcomes.

Results

Seven qualifying studies were identified for full-text extraction, revealing significant heterogeneity across the literature, which hindered direct statistical comparisons. The findings presented inconclusive effects of obesity on fusion outcomes, with ambiguous impacts observed for diabetes mellitus and smoking. Additionally, no discernible variance was observed in functional outcomes across different age groups. Furthermore, steroid usage in rheumatoid arthritis cases demonstrated delayed fusion in revision procedures, while primary outcomes remained uncertain.

Conclusion

This systematic review highlights the need for further research with standardised methodologies to better understand the correlation between pre-existing co-morbidities and outcomes in first metatarsophalangeal joint fusion. By elucidating these relationships, clinicians can better tailor treatment approaches and optimise patient care in this specific Orthopaedic context.

Level of evidence

Level III.

Patients with multiple sclerosis have higher rates of worsening following total hip arthroplasty: a propensity-matched analysis

INTRODUCTION

The progressive nature of multiple sclerosis (MS) may adversely affect outcomes following total hip arthroplasty (THA). As patient-reported outcome measures (PROMs) in this specific group are not well defined, this study aimed to compare the clinical outcomes and the rates of achieving the minimal clinically important difference for improvement (MCID-I) and worsening (MCID-W) between patients with MS and those without MS undergoing THA.

METHODS

We conducted a retrospective analysis of 375 THAs, including 75 MS patients and 300 propensity-matched non-MS patients (4:1), performed between 2016 and 2022. Collected PROMs included Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health Mental and Physical, PROMIS Physical Function short form 10-a (PF-10a), and Hip disability and Osteoarthritis Outcome Score-Physical Function Short-form (HOOS-PS). Preoperative and postoperative PROMs and MCID-I/MCID-W rates were compared.

RESULTS

A total of 375 THAs, including 75 MS and 300 matched non-MS patients, were analysed. MS patients had higher 90-day postoperative complication rates (9.3% vs. 2.3%, p = 0.012) and infection rates (4.0% vs. 0.3%, p = 0.006). The rates of achieving MCID-I and MCID-W were similar for PROMIS Global Mental, PROMIS Global Physical, and HOOS-PS, but MS patients had a higher rate of experiencing MCID-W for PROMIS PF-10a compared to non-MS patients (16.7% vs. 6.5%, p = 0.022). Additionally, MS patients had a longer mean hospital stay (2.4 vs. 1.9 days, p = 0.005) and lower rates of being discharged home (82.7% vs. 94.3%, p < 0.001).

CONCLUSIONS

The present study found that MS patients experience similar rates of MCID-I and MCID-W in most PROMs but have a higher rate of MCID-W for PROMIS PF-10a and increased postoperative complications. These findings highlight the need for careful consideration of postoperative risks despite potential improvements. Further research is needed to explore the impact of MS progression on PROMs and perioperative outcomes.

Prehabilitation in Patients at Risk of Poorer Outcomes Following Total Knee Arthroplasty: A Systematic Review

BACKGROUND

While total knee arthroplasty (TKA) is a generally successful procedure, 10 to 30% of patients still report suboptimal outcomes after surgery. Prehabilitation may offer potential benefits to improve poorer outcomes, although its effectiveness remains uncertain. Our study aimed to assess the efficacy of prehabilitation interventions on patients at risk of poor outcomes following TKA.

METHOD

There were six electronic databases searched up until December 2023. All randomized controlled trials comparing prehabilitation versus usual care in adult patients with osteoarthritis undergoing primary TKA and at risk of poorer outcomes were included. There were four reviewers who independently extracted data and assessed the risk of bias for each study.

RESULTS

The 13 included studies assessed prehabilitation among patients at risk of poor outcomes, identified with various factors including range of motion deficit, functional limitations, high body mass index, psychological factors, frailty, older age, central sensitization, and high risk of discharge to inpatient rehabilitation. The interventions were initiated across a wide range, from 4 to 277 days before surgery. The efficacy of exercise therapy and multidisciplinary rehabilitation remains inconclusive due to limited, low-quality evidence. The results failed to indicate that various forms of nonexercise therapy, including education, psychological intervention, and weight loss therapy, were effective in improving outcomes after TKA. The included studies have major limitations such as small sample size, inappropriate comparators, substantial clinical heterogeneity in intervention characteristics, inadequate blinding for providers and participants, a lack of justification for identifying patients at risk of poor recovery, and a lack of appropriate interventions for managing modifiable factors.

CONCLUSIONS

While our finding fails to show that nonexercise therapy is effective, results of exercise therapy and multidisciplinary rehabilitation remain inconclusive. Further high-quality research is warranted to establish evidence on modifiable factors predictive of poorer postoperative outcomes and investigate how they can be effectively managed.

The number of comorbidities as an important cofactor to ASA class in predicting postoperative outcome: An international multicentre cohort study

BACKGROUND

Multimorbidity is a growing burden in our ageing society and is associated with perioperative morbidity and mortality. Despite several modifications to the ASA physical status classification, multimorbidity as such is still not considered. Thus, the aim of this study was to quantify the burden of comorbidities in perioperative patients and to assess, independent of ASA class, its potential influence on perioperative outcome.

METHODS

In a subpopulation of the prospective ClassIntra® validation study from eight international centres, type and severity of anaesthesia-relevant comorbidities were additionally extracted from electronic medical records for the current study. Patients from the validation study were of all ages, undergoing any type of in-hospital surgery and were followed up until 30 days postoperatively to assess perioperative outcomes. Primary endpoint was the number of comorbidities across ASA classes. The associated postoperative length of hospital stay (pLOS) and Comprehensive Complication Index (CCI®) were secondary endpoints. On a scale from 0 (no complication) to 100 (death) the CCI® measures the severity of postoperative morbidity as a weighted sum of all postoperative complications.

RESULTS

Of 1421 enrolled patients, the mean number of comorbidities significantly increased from 1.5 in ASA I (95% CI, 1.1-1.9) to 10.5 in ASA IV (95% CI, 8.3-12.7) patients. Furthermore, independent of ASA class, postoperative complications measured by the CCI® increased per each comorbidity by 0.81 (95% CI, 0.40-1.23) and so did pLOS (geometric mean ratio, 1.03; 95% CI, 1.01-1.06).

CONCLUSIONS

These data quantify the high prevalence of multimorbidity in the surgical population and show that the number of comorbidities is predictive of negative postoperative outcomes, independent of ASA class.

Influence of Diabetes Mellitus on Postoperative Complications After Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

Background and Objectives: Total knee arthroplasty (TKA) is an effective treatment option for severe knee osteoarthritis. Understanding the impact of diabetes mellitus (DM) on postoperative outcomes is crucial for improving patient satisfaction after TKA. This study aimed to investigate the influence of DM on postoperative complications and mortality after TKA. Materials and Methods: We conducted a systematic review and meta-analysis by searching relevant studies published before December 2023 in the PubMed, EMBASE, Cochrane Library, Medline, and Web of Science databases. The assessment included demographic data, comorbidities, and postoperative complications after primary TKA for both DM and non-DM patients. The odds ratio (OR) was used to represent the estimate of risk of a specific outcome. Results: Thirty-nine studies were finally included in this meta-analysis. Patients with DM had higher rates of periprosthetic joint infection (OR: 1.71, 95% confidence interval [CI]: 1.46-2.00, p < 0.01) and prosthesis revision (OR: 1.37, 95% CI: 1.23-1.52, p < 0.01). Moreover, patients with DM showed an elevated incidence of pneumonia (OR: 1.54, 95% CI: 1.15-2.07, p < 0.01), urinary tract infection (OR: 1.86, 95% CI: 1.07-3.26, p = 0.02), and sepsis (OR: 1.61, 95% CI: 1.46-1.78, p < 0.01). Additionally, the postoperative risk of cardiovascular (OR: 2.49, 95% CI: 1.50-4.17, p < 0.01) and cerebrovascular (OR: 2.38, 95% CI: 1.48-3.81, p < 0.01) events was notably higher in patients with DM. The presence of DM increased the risk of deep vein thrombosis (OR: 1.58, 95% CI: 1.22-2.04, p < 0.01), but did not lead to an increased risk of pulmonary embolism. Most importantly, DM was associated with a higher mortality rate within 30 days after TKA (OR: 1.27, 95% CI: 1.02-1.60, p = 0.03). Conclusions: Patients with DM exhibited a higher rate of postoperative complications after TKA, and DM was associated with a higher mortality rate within 30 days after TKA. It is crucial to educate patients about the perioperative risk and develop evidence-based guidelines to prevent complications after TKA.

Risk of Postoperative Complications After Total Hip and Total Knee Arthroplasty in Behcet Syndrome Patients

BACKGROUND

Behcet syndrome (BS), a multisystem autoimmune disorder, has unclear effects on outcomes after total hip arthroplasty (THA) and total knee arthroplasty (TKA). This study assessed the relative risk of perioperative adverse events in patients with BS.

METHODS

This retrospective cohort study used the PearlDiver M157Ortho data set, a large national administrative database. Total hip arthroplasty and TKA patients with BS were identified and matched 1:4 to those without BS based on patient age, sex, Elixhauser Comorbidity Index scores, and procedure performed (THA or TKA). The incidence of 90-day adverse events was determined and compared by multivariate analysis. 5-year survival to revision surgeries was assessed and compared with the log-rank test.

RESULTS

After matching, 282 THA/TKA patients with BS were identified and compared with 1127 without BS. On multivariate analysis, patients with BS were at independently greater risk of aggregated any (odds ratio [OR] 2.16, P < 0.0001), serious (OR 1.78, P = 0.0051), and minor (OR 2.39, P < 0.0001) adverse events compared with those without BS. No significant difference was observed in 5-year survival to revision surgery (P = 0.3).

CONCLUSIONS

Patients with BS undergoing THA or TKA experienced markedly greater 90-day postoperative adverse events. The findings underscore the need for optimized perioperative management for patients with BS undergoing arthroplasty.

The Impact of Cardiac Arrhythmias on Total Knee Arthroplasty Outcomes

BACKGROUND

Cardiac comorbidities are common in patients undergoing total knee arthroplasty (TKA). While there is an abundance of research showing an association between cardiac abnormalities and poor postoperative outcomes, relatively little is published on specific pathologies. The aim of this study was to assess the impact of cardiac arrhythmias on postoperative outcomes in the setting of TKA.

METHODS

This retrospective cohort study included all patients undergoing TKA from a national database, from 2016 to 2019. Patients who had cardiac arrhythmias were identified via International Classification of Diseases, Tenth Revision, and Clinical Modification/Procedure Coding System codes and served as the cohort of interest. Multivariate regression was performed to compare postoperative outcomes. Gamma regression was performed to assess length of stay and total charges, while negative binomial regression was used to assess 30-day readmission and reoperation. Patient demographic variables and comorbidities, measured via the Elixhauser comorbidity index, were controlled in our regression analysis. Out of a total of 1,906,670 patients, 224,434 (11.76%) had a diagnosed arrhythmia and were included in our analyses.

RESULTS

Those who had arrhythmias had greater odds of both medical (odds ratio [OR] 1.52; P < .001) and surgical complications (OR 2.27; P < .001). They also had greater readmission (OR 2.49; P < .001) and reoperation (OR 1.93; P < .001) within 30 days, longer hospital stays (OR 1.07; P < .001), and greater total charges (OR 1.02; P < .001).

CONCLUSIONS

Cardiac arrhythmia is a common comorbidity in the TKA population and is associated with worse postoperative outcomes. Patients who had arrhythmias had greater odds of both medical and surgical complications requiring readmission or reoperation.

STUDY DESIGN

Level III; Retrospective Cohort Study.

Inpatient Hospital Costs, Emergency Department Visits, and Readmissions for Revision Hip and Knee Arthroplasty

BACKGROUND

Revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) tremendously burden hospital resources. This study evaluated factors influencing perioperative costs, including emergency department (ED) visits, readmissions, and total costs-of-care within 90 days following revision surgery.

METHODS

A retrospective analysis of 772 revision TKAs and THAs performed on 630 subjects at a single center between January 2007 and December 2019 was conducted. Cost data were available from January 2015 to December 2019 for 277 patients. Factors examined included comorbidities, demographic information, preoperative Anesthesia Society of Anesthesiologists score, implant selection, and operative indication using mixed-effects linear regression models.

RESULTS

Among 772 revisions (425 THAs and 347 TKAs), 213 patients required an ED visit, and 90 required hospital readmission within 90 days. There were 22.6% of patients who underwent a second procedure after their initial revision. Liver disease was a significant predictor of ED readmission for THA patients (multivariable odds ratio [OR]: 3.473, P = .001), while aseptic loosening, osteolysis, or instability significantly reduced the odds of readmission for TKA patients (OR: 0.368, P = .014). In terms of ED visits, liver disease increased the odds for THA patients (OR: 1.845, P = .100), and aseptic loosening, osteolysis, or instability decreased the odds for TKA patients (OR: 0.223, P < .001). Increased age was associated with increased costs in both THA and TKA patients, with significant cost factors including congestive heart failure for TKA patients (OR: $7,308.17, P = .004) and kidney disease for THA patients. Revision surgeries took longer than primary ones, with TKA averaging 3.0 hours (1.6 times longer) and THA 2.8 hours (1.5 times longer).

CONCLUSIONS

Liver disease increases ED readmission risk in revision THA, while aseptic loosening, osteolysis, or instability decreases it in revision TKA. Increased age and congestive heart failure are associated with increased costs. These findings inform postoperative care and resource allocation in revision arthroplasty.

LEVEL OF EVIDENCE

Economic and Decision Analysis, Level IV.

Association between diabetes mellitus and total hip arthroplasty outcomes: an observational study using the US National Inpatient Sample

OBJECTIVES

To investigate the association of diabetes with postoperative outcomes in patients undergoing primary total hip arthroplasty (THA).

DESIGN

Retrospective cohort study using data from the US National Inpatient Sample (NIS).

SETTING

Study cohort was hospitalisations for primary THA in the USA, identified from the 2016-2020 NIS.

PARTICIPANTS

We identified 2 467 215 adults in the 2016-2020 NIS who underwent primary THA using International Classification of Diseases, 10th Revision codes. Primary THA hospitlizations were analysed as the overall group and also stratified by the underlying primary diagnosis for THA.

OUTCOME MEASURES

Outcome measures of interest were the length of hospital stay>the median, total hospital charges>the median, inpatient mortality, non-routine discharge, need for blood transfusion, prosthetic fracture, prosthetic dislocation and postprocedural infection, including periprosthetic joint infection, deep surgical site infection and postprocedural sepsis.

RESULTS

Among 2 467 215 patients who underwent primary THA, the mean age was 68.7 years, 58.3% were female, 85.7% were white, 61.7% had Medicare payer and 20.4% had a Deyo-Charlson index (adjusted to exclude diabetes mellitus) of 2 or higher. 416 850 (17%) patients had diabetes. In multivariable-adjusted logistic regression in the overall cohort, diabetes was associated with higher odds of a longer hospital stay (adjusted OR (aOR) 1.38; 95% CI 1.35 to 1.41), higher total charges (aOR 1.11; 95% CI 1.09 to 1.13), non-routine discharge (aOR 1.18; 95% CI 1.15 to 1.20), the need for blood transfusion (aOR 1.19; 95% CI 1.15 to 1.23), postprocedural infection (aOR 1.62; 95% CI 1.10 to 2.40) and periprosthetic joint infection (aOR 1.91; 95% CI 1.12 to 3.24). We noted a lack of some associations in the avascular necrosis and inflammatory arthritis cohorts (p>0.05).

CONCLUSION

Diabetes was associated with increased healthcare utilisation, blood transfusion and postprocedural infection risk following primary THA. Optimisation of diabetes with preoperative medical management and/or institution of specific postoperative pathways may improve these outcomes. Larger studies are needed in avascular necrosis and inflammatory arthritis cohorts undergoing primary THA.

Complications, Readmissions, and Reoperations in Outpatient vs Inpatient Total Ankle Arthroplasty: A Systematic Review and Meta-analysis

Background

Total ankle arthroplasty (TAA) has primarily been performed in the inpatient setting. However, with the advent of fast-tracked joint arthroplasty protocols, TAA has slowly been shifting to the outpatient setting. Therefore, this systematic review aims to evaluate outcomes of outpatient TAA and compare them to inpatient TAA.

Methods

A literature search was performed on October 23, 2023, in the PubMed, Embase, and CENTRAL databases using the PRISMA guidelines. Studies were included if they reported on outcomes of outpatient TAA or compared outcomes between outpatient and inpatient TAA. Pooled odds ratios (ORs) and mean differences were calculated using a random effects model. Quality assessment was performed using the MINORS criteria.

Results

12 studies were included, with 4 outpatient-only and 8 outpatient-inpatient comparative studies. Patients in the outpatient group were relatively younger, had a lower body mass index, and had fewer comorbidities relative to the inpatient group. For outpatient vs inpatient TAA, the pooled complication rate was 2.6% vs 3.6%, readmission rate was 2.5% vs 4%, and reoperation rate was 3.6% vs 5.5%. We found significantly lower odds of complications (OR = 0.47, CI: 0.26-0.85; P = .01), readmissions (OR = 0.63, CI: 0.54-0.74; P < .00001), and reoperations (OR = 0.66, CI: 0.46-0.95; P = .03) in the outpatient vs inpatient group.

Conclusion

Although this analysis is limited by the dominance of data included from a single study, we found that outpatient TAA was generally performed on lower-risk patients and was associated with lower rates of complications, readmissions, and reoperations compared with inpatient TAA.

The influence of body mass index on patient-reported outcome measures following total hip arthroplasty: a retrospective study of 3,903 Cases

BACKGROUND

The influence of obesity on patient-reported outcome measures (PROMs) following total hip arthroplasty (THA) is currently controversial. This study aimed to compare PROM scores for pain, functional status, and global physical/mental health based on body mass index (BMI) classification.

METHODS

Primary, elective THA procedures at a single institution between 2018 and 2021 were retrospectively reviewed, and patients were stratified into four groups based on BMI: normal weight (18.5-24.99 kg/m2), overweight (25-29.99 kg/m2), obese (30-39.99 kg/m2), and morbidly obese (> 40 kg/m2). Patient-Reported Outcome Measurement Information System (PROMIS) and Hip Disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS, JR) scores were collected. Preoperative, postoperative, and pre/post- changes (pre/post-Δ) in scores were compared between groups. Multiple linear regression was used to assess for confounders.

RESULTS

We analyzed 3,404 patients undergoing 3,903 THAs, including 919 (23.5%) normal weight, 1,374 (35.2%) overweight, 1,356 (35.2%) obese, and 254 (6.5%) morbidly obese cases. HOOS, JR scores were worse preoperatively and postoperatively for higher BMI classes, however HOOS, JR pre/post-Δ was comparable between groups. All PROMIS measures were worse preoperatively and postoperatively in higher BMI classes, though pre/post-Δ were comparable for all groups. Clinically significant improvements for all BMI classes were observed in all PROM metrics except PROMIS mental health. Regression analysis demonstrated that obesity, but not morbid obesity, was independently associated with greater improvement in HOOS, JR.

CONCLUSIONS

Obese patients undergoing THA achieve lower absolute scores for pain, function, and self-perceived health, despite achieving comparable relative improvements in pain and function with surgery. Denying THA based on BMI restricts patients from clinically beneficial improvements comparable to those of non-obese patients, though morbidly obese patients may benefit from additional weight loss to achieve maximal functional improvement.

Adult Reconstruction Surgeons Manage Patients With Higher Medical Complexities and Still Achieve Comparable Outcomes to Sports Medicine Surgeons Following Total Knee Arthroplasty

Background

Orthopaedic surgeons who are fellowship-trained in adult reconstruction (AR) specialize specifically in total joint arthroplasty, including total knee arthroplasty (TKA). However, TKA procedures are not only performed by AR surgeons. The purpose of this study was to compare the patient demographics and postoperative outcomes of patients who had a TKA procedure performed by an AR surgeon vs a sports medicine (SM) surgeon.

Methods

A retrospective cohort study was conducted using a national insurance database. Patients who underwent a primary elective TKA procedure by an AR surgeon (n = 56,570) and an SM surgeon (n = 72,888) were identified. Patient demographics, rates of joint complications within 2 years, and medical complications within 90 days postoperatively were compared using multivariable logistic regression.

Results

Compared to the cohort of patients undergoing TKA by SM surgeons, the patient cohort of AR surgeons had a higher mean Elixhauser comorbidity index (4.2 vs 4.0, P < .001), and had significantly higher rates of several comorbidities. Within 90 days, patients of AR surgeons demonstrated significantly lower rates of acute kidney injury and transfusions. When compared to patients of SM surgeons, patients of AR surgeons demonstrated significantly lower rate of manipulation under anesthesia or lysis of adhesions within 2 years. Rates of all other joint-related complications were statistically comparable between the 2 cohorts.

Conclusions

As a cohort, AR surgeons perform TKA on a higher-risk cohort of patients compared to sports medicine surgeons. Despite the higher-risk patient population, outcomes of TKA by AR surgeons appear equivalent compared to their SM colleagues.

Sex and age differences in the use of analgesic drugs before and after primary total hip arthroplasty in 105,520 Danish patients

BACKGROUND

We examined analgesic drug use before and after total hip arthroplasty (THA) by sex and age, and impact of comorbidity in that context.

METHODS

Using Danish nationwide medical registries, we included 105,520 THA patients (1996-2018). We calculated prevalence of overall analgesic drug use and use of NSAIDs and opioids separately in four quarters before (-Q4 to -Q1) and after THA (Q1 to Q4). -Q4 and Q4 was compared using prevalence rate ratios (PRR) with 95% confidence interval (CI).

RESULTS

Among women, analgesic drug use was 46% in -Q4, 65% in Q1, but decreased to 31% in Q4 (PRR: 0.68 (CI: 0.67-0.69)). Among men, these numbers were 39% in -Q4, 62% in Q1, and 23% in Q4 (PRR: 0.61 (CI: 0.60-0.63)). Analgesic drug use was higher among older patients in all quarters except Q1. Analgesic drug use decreased from 40% in -Q4 to 25% in Q4 (PRR: 0.62 (CI: 0.59-0.64)) in patients <55 years, and from 44% to 30% in patients >85 years, (PRR: 0.67 (CI: 0.63-0.71)). Women used more NSAIDs and opioids than men. Older patients used more opioids compared to younger, while variation in NSAID use by age was small. Decrease in analgesic drug use from -Q4 to Q4 was least pronounced in patients with comorbidity history.

CONCLUSIONS

Women and older patients have higher prevalence of analgesic drug use before and after THA, and a smallest reduction in analgesic drug use from before to after THA. Comorbidity history modified these associations.

Increased Complication Risk Associated With Simultaneous Bilateral Total Hip Arthroplasty: A Contemporary, Matched Cohort Analysis

BACKGROUND

Simultaneous bilateral total hip arthroplasty (sbTHA) continues to be performed in patients who have bilateral end-stage osteoarthritis. However, few studies have evaluated the risk associated with this practice compared to unilateral total hip arthroplasty (THA).

METHODS

Using a large national database, primary, elective sbTHAs, and unilateral THAs were identified from January 1, 2015 to December 31, 2021. The sbTHAs were matched to unilateral THAs at a 1:5 ratio on age, sex, and pertinent comorbidities. Patient characteristics and comorbidities, and hospital factors were compared between both cohorts. Additionally, 90-day risk of postoperative complications, readmissions, and in-hospital deaths were assessed. After matching, 2,913 sbTHAs were compared to 14,565 unilateral THAs with an average age of 58.5 ± 10.0 years.

RESULTS

Compared to unilateral patients, sbTHA patients demonstrated higher rates of pulmonary embolism (PE) (0.4 versus 0.2%, P = .002), acute renal failure (1.2 versus 0.7%, P = .007), acute blood loss anemia (30.4 versus 16.7%, P < .001), and need for transfusion (6.6 versus 1.8%, P < .001). After accounting for confounders, sbTHA patients demonstrated increased risk of PE (adjusted odds ratio [aOR]: 3.76, 95% CI: 1.84 to 7.70, P < .001), acute renal failure (aOR: 1.83, 95% CI: 1.23 to 2.72, P = .003), acute blood loss anemia (aOR: 2.3, 95% CI: 2.10 to 2.53, P < .001), and transfusion (aOR: 4.08, 95% CI: 3.35 to 4.98, P < .001) compared to unilateral THA patients.

CONCLUSION

The practice of performing sbTHA was associated with an increased risk of PE, acute renal failure, and risk of transfusion. Careful evaluation of patient-specific risk factors is warranted when considering these bilateral procedures.

Prognostic Factors for Postoperative Chronic Pain after Knee or Hip Replacement in Patients with Knee or Hip Osteoarthritis: An Umbrella Review

Knee and hip osteoarthritis are highly prevalent in the older population. Management of osteoarthritis-related pain includes conservative or surgical treatment. Although knee or hip joint replacement is associated with positive outcomes, up to 30% of patients report postoperative pain in the first two years. This study aimed to synthesize current evidence on prognostic factors for predicting postoperative pain after knee or hip replacement. An umbrella review of systematic reviews was conducted to summarize the magnitude and quality of the evidence for prognostic preoperative factors predictive of postoperative chronic pain (>6 months after surgery) in patients who had received knee or hip replacement. Searches were conducted in MEDLINE, CINAHL, PubMed, PEDro, SCOPUS, Cochrane Library, and Web of Science databases from inception up to 5 August 2022 for reviews published in the English language. A narrative synthesis, a risk of bias assessment, and an evaluation of the evidence confidence were performed. Eighteen reviews (nine on knee surgery, four on hip replacement, and seven on both hip/knee replacement) were included. From 44 potential preoperative prognostic factors, just 20 were judged as having high or moderate confidence for robust findings. Race, opioid use, preoperative function, neuropathic pain symptoms, pain catastrophizing, anxiety, other pain sites, fear of movement, social support, preoperative pain, mental health, coping strategies, central sensitization-associated symptoms, and depression had high/moderate confidence for an association with postoperative chronic pain. Some comorbidities such as heart disease, stroke, lung disease, nervous system disorders, and poor circulation had high/moderate confidence for no association with postoperative chronic pain. This review has identified multiple preoperative factors (i.e., sociodemographic, clinical, psychological, cognitive) associated with postoperative chronic pain after knee or hip replacement. These factors may be used for identifying individuals at a risk of developing postoperative chronic pain. Further research can investigate the impact of using such prognostic data on treatment decisions and patient outcomes.

Predicting whether patients will achieve minimal clinically important differences following hip or knee arthroplasty

Aims

A substantial fraction of patients undergoing knee arthroplasty (KA) or hip arthroplasty (HA) do not achieve an improvement as high as the minimal clinically important difference (MCID), i.e. do not achieve a meaningful improvement. Using three patient-reported outcome measures (PROMs), our aim was: 1) to assess machine learning (ML), the simple pre-surgery PROM score, and logistic-regression (LR)-derived performance in their prediction of whether patients undergoing HA or KA achieve an improvement as high or higher than a calculated MCID; and 2) to test whether ML is able to outperform LR or pre-surgery PROM scores in predictive performance.

Methods

MCIDs were derived using the change difference method in a sample of 1,843 HA and 1,546 KA patients. An artificial neural network, a gradient boosting machine, least absolute shrinkage and selection operator (LASSO) regression, ridge regression, elastic net, random forest, LR, and pre-surgery PROM scores were applied to predict MCID for the following PROMs: EuroQol five-dimension, five-level questionnaire (EQ-5D-5L), EQ visual analogue scale (EQ-VAS), Hip disability and Osteoarthritis Outcome Score-Physical Function Short-form (HOOS-PS), and Knee injury and Osteoarthritis Outcome Score-Physical Function Short-form (KOOS-PS).

Results

Predictive performance of the best models per outcome ranged from 0.71 for HOOS-PS to 0.84 for EQ-VAS (HA sample). ML statistically significantly outperformed LR and pre-surgery PROM scores in two out of six cases.

Conclusion

MCIDs can be predicted with reasonable performance. ML was able to outperform traditional methods, although only in a minority of cases.

Can ultrasound-guided radiofrequency ablation of genicular nerves of the knee, be performed without locating corresponding arterial pulsations-a cadaveric study

INTRODUCTION

Given the rising prevalence of knee osteoarthritis, radiofrequency ablation of genicular nerves (RFA) has emerged as a promising treatment option for knee pain. The knee has an extremely complex and variable innervation with nearly 13 genicular nerves described. The frequently ablated genicular nerves are the superomedial (SMGN), the superolateral (SLGN), and the inferomedial (IMGN) genicular nerves. Conventionally, under ultrasound guidance, these nerves are ablated near the corresponding arterial pulsations, but due to the rich vascular anastomosis around the knee joint, identifying the arteries corresponding to these constant genicular nerves can be tedious unless guided by some bony landmarks. In this study, we have evaluated whether it is possible to accurately target these three genicular nerves by just locating bony landmarks under ultrasound in human cadaveric knee specimens.

METHODS

Fifteen formalin-fixed cadaveric knee specimens were studied. SMGN was targeted 1 cm anterior to the adductor tubercle in the axial view. For SLGN, in the coronal view, the junction of the lateral femoral condyle and shaft was identified, and at the same level in the axial view, the crest between the lateral and posterior femoral cortex was targeted. For IMGN in the coronal view, the midpoint between the most prominent part of the medial tibial condyle and the insertion of the deep fibers of the medial collateral ligament was marked. The medial end of the medial tibial cortex was then targeted at the same level in the axial view. The needle was inserted from anterior to posterior, with an in-plane approach for all nerves. Eosin, 2% W/V, in 0.1 ml was injected. Microdissection was done while keeping the needle in situ. Staining of the nerve was considered a positive outcome, and the percentage was calculated. The nerve-to-needle distance was measured, and the mean with an interquartile range was calculated.

RESULT

The accuracies of ultrasound-guided bony landmarks of SMGN, SLGN, and IMGN were 100% in terms of staining, with average nerve-to-needle distances of 1.67, 3.2, and 1.8 mm respectively.

CONCLUSION

It is with 100% accuracy, that we can perform RFA of SMGN, SLGN, and IMGN under ultrasound guidance, by locating the aforementioned bony landmarks.

Does body mass index influence improvement in patient reported outcomes following total knee arthroplasty? A retrospective analysis of 3918 cases

PURPOSE

The study aimed to determine whether body mass index (BMI) classification for patients undergoing total knee arthroplasty (TKA) is associated with differences in mean patient reported outcome measure (PROM) score improvements across multiple domains-including pain, functional status, mental health, and global physical health. We hypothesized that patients with larger BMIs would have worse preoperative and postoperative PROM scores, though improvements in scores would be comparable between groups.

MATERIALS AND METHODS

Patients undergoing primary TKA from 2018 to 2021 were retrospectively reviewed and stratified into four groups: Normal Weight; 18.5-25 kg/m², Overweight; 25.01-30 kg/m², Obese; 30.01-40 kg/m², and Morbidly Obese > 40 kg/m². Preoperative, postoperative, and pre/post-changes (Δ) in knee injury and osteoarthritis, joint replacement (KOOS, JR) and Patient-Reported Outcome Measurement Information System (PROMIS) measures of pain intensity, pain interference, physical function, mobility, mental health, and physical health were compared. Multivariate linear regression was used to assess for confounding comorbid conditions.

RESULTS

In univariate analysis, patients with larger BMIs had worse scores for KOOS, JR and all PROMIS metrics preoperatively. Postoperatively, scores for KOOS, JR and PROMIS pain interference, mobility, and physical health were statistically worse in higher BMI groups, though differences were not clinically significant. Morbidly obese patients achieved greater pre/post-Δ improvements in KOOS, JR and global physical health scores. Multivariate regression analysis showed high BMI was independently associated with greater pre/post-Δ improvements in KOOS, JR and global health scores.

CONCLUSION

Obese patients report worse preoperative scores for function and health, but greater pre/post-Δ improvements in KOOS, JR and physical health scores following TKA. Quality of life benefits of TKA in obese patients should be a factor when assessing surgical candidacy.

Complications and Safety of Simultaneous Bilateral Total Knee Arthroplasty: A Patient Characteristic and Comorbidity-Matched Analysis

BACKGROUND

Total knee arthroplasty (TKA) is a highly successful surgical procedure that decreases pain and improves function. Many patients who undergo TKA may require surgical intervention on both extremities because of bilateral osteoarthritis. The purpose of this study was to evaluate the safety of simultaneous bilateral TKA compared with that of unilateral TKA.

METHODS

Patients who underwent unilateral or simultaneous bilateral primary, elective TKA from 2015 to 2020 were identified using the Premier Healthcare Database. Subsequently, the simultaneous bilateral TKA cohort was matched to the unilateral TKA cohort in a 1:6 ratio by age, sex, race, and presence of pertinent comorbidities. Patient characteristics, hospital factors, and comorbidities were compared between the cohorts. The 90-day risks of postoperative complications, readmission, and in-hospital death were assessed. Differences were assessed using univariable regression, and multivariable regression analyses were performed to account for potential confounders.

RESULTS

Overall, 21,044 patients who underwent simultaneous bilateral TKA and 126,264 matched patients who underwent unilateral TKA were included. After accounting for confounding factors, patients who underwent simultaneous bilateral TKA demonstrated a significantly increased risk of postoperative complications, including pulmonary embolism (adjusted odds ratio [OR], 2.13 [95% confidence interval (CI), 1.57 to 2.89]; p < 0.001), stroke (adjusted OR, 2.21 [95% CI, 1.42 to 3.42]; p < 0.001), acute blood loss anemia (adjusted OR, 2.06 [95% CI, 1.99 to 2.13]; p < 0.001), and transfusion (adjusted OR, 7.84 [95% CI, 7.16 to 8.59]; p < 0.001). Patients who underwent simultaneous bilateral TKA were at increased risk of 90-day readmission (adjusted OR, 1.35 [95% CI, 1.24 to 1.48]; p < 0.001).

CONCLUSIONS

Simultaneous bilateral TKA was associated with increased rates of complications including pulmonary embolism, stroke, and transfusion. Orthopaedic surgeons and patients should consider these potential complications when contemplating simultaneous bilateral TKA. When simultaneous bilateral TKA is pursued, patient counseling and thorough medical optimization should be performed.

LEVEL OF EVIDENCE

Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Cost-effectiveness analysis of five anti-obesity medications from a US payer's perspective

BACKGROUND AND AIMS

To determine the cost-effectiveness of anti-obesity medications (AOM): tirzepatide, semaglutide, liraglutide, phentermine plus topiramate (PpT), and naltrexone plus bupropion (NpB).

METHODS AND RESULTS

From a U.S. perspective we developed a Markov model to simulate weight change over a 40-year time horizon using results from clinical studies. According to the body mass index (BMI), cardiovascular diseases, diabetes and mortality risk were the health states considered in the model, being mutually exclusive. Costs of AOM, adverse events, cardiovascular events, and diabetes were included. We applied a 3% per-year discount rate and calculated the incremental cost-effectiveness ratios (ICERs) of cost per quality-adjusted life-year (QALY) gained. Probabilistic sensitivity analyses incorporated uncertainty in input parameters. A deterministic analysis was conducted to determine the robustness of the model. The model included a cohort of 78.2% females with a mean age of 45 years and BMI of 37.1 (SD 4.9) for females and 36.8 (SD 4.9) for males. NpB and PpT were the least costly medications and, all medications differed no more than 0.5 QALYs. Tirzepatide ICER was $355,616 per QALY. Liraglutide and semaglutide options were dominated by PpT.

CONCLUSION

Compared to other AOM, PpT was lowest cost treatment with nearly identical QALYs with other agents.

Primary knee arthroplasty for osteoarthritis restores patients' health-related quality of life to normal population levels

This study investigates whether primary knee arthroplasty (KA) restores health-related quality of life (HRQoL) to levels expected in the general population. This retrospective case-control study compared HRQoL data from two sources: patients undergoing primary KA in a university-teaching hospital (2013 to 2019), and the Health Survey for England (HSE; 2010 to 2012). Patient-level data from the HSE were used to represent the general population. Propensity score matching was used to balance covariates and facilitate group comparisons. A propensity score was estimated using logistic regression based upon the covariates sex, age, and BMI. Two matched cohorts with 3,029 patients each were obtained for the adjusted analyses (median age 70.3 (interquartile range (IQR) 64 to 77); number of female patients 3,233 (53.4%); median BMI 29.7 kg/m² (IQR 26.5 to 33.7)). HRQoL was measured using the three-level version of the EuroQol five-dimension questionnaire (EQ-5D-3L), and summarized using the Index and EuroQol visual analogue scale (EQ-VAS) scores. Patients awaiting KA had significantly lower EQ-5D-3L Index scores than the general population (median 0.620 (IQR 0.16 to 0.69) vs median 0.796 (IQR 0.69 to 1.00); p < 0.001). By one year postoperatively, the median EQ-5D-3L Index score improved significantly in the KA cohort (mean change 0.32 (SD 0.33); p < 0.001), and demonstrated no clinically relevant differences when compared to the general population (median 0.796 (IQR 0.69 to 1.00) vs median 0.796 (IQR 0.69 to 1.00)). Compared to the general population cohort, the postoperative EQ-VAS was significantly higher in the KA cohort (p < 0.001). Subgroup comparisons demonstrated that older age groups had statistically better EQ-VAS scores than matched peers in the general population. Patients awaiting KA for osteoarthritis had significantly poorer HRQoL than the general population. However, within one year of surgery, primary KA restored HRQoL to levels expected for the patient's age-, BMI-, and sex-matched peers.

Patient-rated satisfaction and improvement following hip and knee replacements: Development of prediction models

RATIONALE

Effective preoperative assessments of determinants of health status and function may improve postoperative outcomes.

AIMS AND OBJECTIVES

We developed risk scores of preoperative patient factors and patient-reported outcome measures (PROMs) as predictors of patient-rated satisfaction and improvement following hip and knee replacements.

PATIENTS AND METHODS

Prospectively collected National Health Service and independent sector patient data (n = 30,457), including patients' self-reported demographics, comorbidities, PROMs (Oxford Hip/Knee score (OHS/OKS) and European Quality of Life (EQ5D index and health-scale), were analysed. Outcomes were defined as patient-reported satisfaction and improvement following surgery at 7-month follow-up. Univariable and multivariable-adjusted logistic regressions were undertaken to build prediction models; model discrimination was evaluated with the concordance index (c-index) and nomograms were developed to allow the estimation of probabilities.

RESULTS

Of the 14,651 subjects with responses for satisfaction following hip replacements 564 (3.8%) reported dissatisfaction, and 1433 (9.2%) of the 15,560 following knee replacement reported dissatisfaction. A total of 14,662 had responses for perceived improvement following hip replacement (lack of improvement in 391; 2.7%) and 15,588 following knee replacement (lack of improvements in 1092; 7.0%). Patients reporting poor outcomes had worse preoperative PROMs. Several factors, including age, gender, patient comorbidities and EQ5D, were included in the final prediction models: C-indices of these models were 0.613 and 0.618 for dissatisfaction and lack of improvement, respectively, for hip replacement and 0.614 and 0.598, respectively, for knee replacement.

CONCLUSIONS

Using easily accessible preoperative patient factors, including PROMs, we developed models which may help predict dissatisfaction and lack of improvement following hip and knee replacements and facilitate risk stratification and decision-making processes.

The Use of Risk Scores in Patient Preoperative Optimization for Total Joint Arthroplasty: A Survey of Orthopaedic Nurse Navigators

Preoperative optimization of patients seeking total joint arthroplasty is becoming more common, and risk scores, which provide an estimate for the risk of complications following procedures, are often used to assist with the preoperative decision-making process. The aim of this study was to characterize the use of risk scores at institutions that utilize nurse navigators in the preoperative optimization process. The survey included 207 nurse navigators identified via the National Association of Orthopaedic Nurses to better understand the use of risk scores in preoperative optimization and the different factors that are included in these risk scores. The study found that 48% of responding nurse navigators utilized risk scores in the preoperative optimization process. These risk scores often included patient comorbidities such as diabetes (85%) and body mass index (87%). Risk scores are commonly used by nurse navigators in preoperative optimization and involve a variety of comorbidities and patient-specific factors.

Can extant comorbidity indices identify patients who experience poor outcomes following total joint arthroplasty?

INTRODUCTION

It is uncertain if generic comorbidity indices commonly used in orthopedics accurately predict outcomes after total hip (THA) or knee arthroplasty (TKA). The purpose of this study was to determine the predictive ability of such comorbidity indices for: (1) 30-day mortality; (2) 30-day rate of major and minor complications; (3) discharge disposition; and (4) extended length of stay (LOS).

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was retrospectively reviewed for all patients who underwent elective THA (n = 202,488) or TKA (n = 230,823) from 2011 to 2019. The American Society of Anesthesiologists (ASA) physical status classification system score, modified Charlson Comorbidity Index (mCCI), Elixhauser Comorbidity Measure (ECM), and 5-Factor Modified Frailty Index (mFI-5) were calculated for each patient. Logistic regression models predicting 30-day mortality, discharge disposition, LOS greater than 1 day, and 30-day major and minor complications were fit for each index.

RESULTS

The ASA classification (C-statistic = 0.773 for THA and TKA) and mCCI (THA: c-statistic = 0.781; TKA: C-statistic = 0.771) were good models for predicting 30-day mortality. However, ASA and mCCI were not predictive of major and minor complications, discharge disposition, or LOS. The ECM and mFI-5 did not reliably predict any outcomes of interest.

CONCLUSION

ASA and mCCI are good models for predicting 30-day mortality after THA and TKA. However, similar to ECM and mFI-5, these generic comorbidity risk-assessment tools do not adequately predict 30-day postoperative outcomes or in-hospital metrics. This highlights the need for an updated, data-driven approach for standardized comorbidity reporting and risk assessment in arthroplasty.

Clinical Frailty Scale is a better predictor for adverse post-operative complications and functional outcomes than Modified Frailty Index and Charlson Comorbidity Index after total knee arthroplasty

PURPOSE

Studies have demonstrated correlations between frailty and comorbidity scores with adverse outcomes in total knee replacement (TKR). However, there is a lack of consensus on the most suitable pre-operative assessment tool. This study aims to compare Clinical Frailty Scale (CFS), Modified Frailty Index (MFI), and Charlson Comorbidity Index (CCI) in predicting adverse post-operative complications and functional outcomes following a unilateral TKR.

METHODS

In total, 811 unilateral TKR patients from a tertiary hospital were identified. Pre-operative variables were age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA) class, CFS, MFI, and CCI. Binary logistic regression analysis was performed to ascertain odd ratios of pre-operative variables on adverse post-operative complications (length of stay < LOS >, complications, ICU/HD admission, discharge location, 30-day readmission, 2-year reoperation). Multiple linear regression analyses were used to estimate the standardized effects of pre-operative variables on the Knee Society Functional Score (KSFS), Knee Society Knee Score (KSKS), Oxford Knee Score (OKS), and 36-Item Short Form Survey (SF-36).

RESULTS

CFS is a strong predictor for LOS (OR 1.876, p < 0.001), complications (OR 1.83-4.97, p < 0.05), discharge location (OR 1.84, p < 0.001), and 2-year reoperation rate (OR 1.98, p < .001). ASA and MFI were predictors for ICU/HD admission (OR:4.04, p = 0.002; OR 1.58, p = 0.022, respectively). None of the scores was predictive for 30-day readmission. A higher CFS was associated with a worse outcome for 6-month KSS, 2-year KSS, 6-month OKS, 2-year OKS, and 6-month SF-36.

CONCLUSION

CFS is a superior predictor for post-operative complications and functional outcomes than MFI and CCI in unilateral TKR patients. This suggests the importance of assessing pre-operative functional status when planning for TKR.

LEVEL OF EVIDENCE

Diagnostic, II.

Predicting Hospital Readmissions After Total Shoulder Arthroplasty Within a Bundled Payment Cohort

INTRODUCTION

Given the rising demand for shoulder arthroplasty, understanding risk factors associated with unplanned hospital readmission is imperative. No study to date has examined the influence of patient and hospital-specific factors as a predictive model for 90-day readmissions within a bundled payment cohort after primary shoulder arthroplasty. The purpose of this study was to determine predictive factors for 90-day readmissions after primary shoulder arthroplasty within a bundled payment cohort.

METHODS

After obtaining IRB approval, a retrospective review of a consecutive series of Medicare patients undergoing primary shoulder arthroplasty from 2014 to 2020 at a single academic institution was conducted. Patient demographic data, surgical variables, medical comorbidity profiles, medical risk scores, and social risk scores were collected. Postoperative variables included length of hospital stay, discharge location, and 90-day readmissions. Multivariate analysis was conducted to determine the independent risk factors of 90-day readmission.

RESULTS

Overall, 3.6% of primary shoulder arthroplasty patients (127/3,523) were readmitted within 90 days. Readmitted patients had a longer hospital course (1.75 versus 1.45 P = 0.006), higher comorbidity profile (4.64 versus 4.24 P = 0.001), higher social risk score (7.96 versus 6.9 P = 0.008), and higher medical risk score (10.1 versus 6.96 P < 0.001) and were more likely to require a home health aide or be discharged to an inpatient rehab facility or skilled nursing facility ( P = 0.002). Following multivariate analysis, an elevated medical risk score was associated with an increased risk of readmission (odds ratio = 1.05, P < 0.001).

DISCUSSION

This study demonstrates medical risk scores to be an independent risk factor of increased risk of 90-day hospital readmissions after primary shoulder arthroplasty within a bundled payment patient population. Additional incorporation of medical risk scores may be a beneficial adjunct in preoperative prediction for readmission and the potentially higher episode-of-care costs.

LEVEL OF EVIDENCE

Level III, retrospective cohort.

Repeat revision TKR for failed management of peri-prosthetic infection has long-term success but often require multiple operations: a case control study

BACKGROUND

Prosthetic joint infection (PJI) is associated with poor outcomes and catastrophic complications. The aim of this study was to present the outcomes of re-revision surgery for PJI of the knee following previous failed two-stage exchange arthroplasty.

MATERIALS AND METHODS

A retrospective analysis was performed of 32 patients who underwent re-revision knee arthroplasty, having already undergone at least one previous two-stage exchange for PJI with a minimum follow-up of two-years for alive patients. Outcomes were compared to a matched control of two-stage revisions for PJI of a primary knee replacement also containing 32 patients. Outcomes investigated were eradication of infection, re-operation, mortality and limb-salvage rate.

RESULTS

Successful eradication of infection was achieved in 50% of patients following re-revision surgery, compared with 91% following two-stage exchange of primary knee replacement for PJI (p < 0.001). Fourteen (44%) patients required further re-operation compared with three (9%) patients in the primary group (p = 0.006). Amputation was performed in one case (3%) with thirteen patients (92%) who had infection controlled by debridement, antibiotics and implant retention (DAIR), further revision surgery or arthrodesis. Two patients died with infection (6%) and the long-term rate for infection control was 91%. The mean number of procedures following surgery for the re-revision group was 2.8 (0-9) compared with 0.13 (0-1) for the primary two-stage group (p < 0.001). Five-year patient survival was 90.6% (95% CI 77.1-100). The limb-salvage rate for the re-revision cohort was 97%.

CONCLUSION

Outcomes for re-revision knee arthroplasty for PJI have higher re-operation and failure rates, but no worse mortality than in revisions of primary knee replacements. Failures can successfully be managed by further operation.

External Validation of Prediction Models for Surgical Complications in People Considering Total Hip or Knee Arthroplasty Was Successful for Delirium but Not for Surgical Site Infection, Postoperative Bleeding, and Nerve Damage: A Retrospective Cohort Study

Although several models for the prediction of surgical complications after primary total hip or total knee replacement (THA and TKA, respectively) are available, only a few models have been externally validated. The aim of this study was to externally validate four previously developed models for the prediction of surgical complications in people considering primary THA or TKA. We included 2614 patients who underwent primary THA or TKA in secondary care between 2017 and 2020. Individual predicted probabilities of the risk for surgical complication per outcome (i.e., surgical site infection, postoperative bleeding, delirium, and nerve damage) were calculated for each model. The discriminative performance of patients with and without the outcome was assessed with the area under the receiver operating characteristic curve (AUC), and predictive performance was assessed with calibration plots. The predicted risk for all models varied between <0.01 and 33.5%. Good discriminative performance was found for the model for delirium with an AUC of 84% (95% CI of 0.82-0.87). For all other outcomes, poor discriminative performance was found; 55% (95% CI of 0.52-0.58) for the model for surgical site infection, 61% (95% CI of 0.59-0.64) for the model for postoperative bleeding, and 57% (95% CI of 0.53-0.61) for the model for nerve damage. Calibration of the model for delirium was moderate, resulting in an underestimation of the actual probability between 2 and 6%, and exceeding 8%. Calibration of all other models was poor. Our external validation of four internally validated prediction models for surgical complications after THA and TKA demonstrated a lack of predictive accuracy when applied in another Dutch hospital population, with the exception of the model for delirium. This model included age, the presence of a heart disease, and the presence of a disease of the central nervous system as predictor variables. We recommend that clinicians use this simple and straightforward delirium model during preoperative counselling, shared decision-making, and early delirium precautionary interventions.

Factors associated with persistent postsurgical pain after total knee or hip joint replacement: a systematic review and meta-analysis

Studies have identified demographic, clinical, psychosocial, and perioperative variables associated with persistent pain after a variety of surgeries. This study aimed to perform a systematic review and meta-analysis of factors associated with persistent pain after total knee replacement (TKR) and total hip replacement (THR) surgeries. To meet the inclusion criteria, studies were required to assess variables before or at the time of surgery, include a persistent postsurgical pain (PPSP) outcome measure at least 2 months after a TKR or THR surgery, and include a statistical analysis of the effect of the risk factor(s) on the outcome measure. Outcomes from studies implementing univariate and multivariable statistical models were analyzed separately. Where possible, data from univariate analyses on the same factors were combined in a meta-analysis. Eighty-one studies involving 171,354 patients were included in the review. Because of the heterogeneity of assessment methods, only 44% of the studies allowed meaningful meta-analysis. In meta-analyses, state anxiety (but not trait anxiety) scores and higher depression scores on the Beck Depression Inventory were associated with an increased risk of PPSP after TKR. In the qualitative summary of multivariable analyses, higher preoperative pain scores were associated with PPSP after TKR or THR. This review systematically assessed factors associated with an increased risk of PPSP after TKR and THR and highlights current knowledge gaps that can be addressed by future research.

Pre- and Post-Operative Rehabilitation Interventions in Patients at Risk of Poor Outcomes Following Knee or Hip Arthroplasty: Protocol for Two Systematic Reviews

Objective

Total knee (TKA) and hip arthroplasty (THA) are successful procedures in treating end-stage osteoarthritis when nonoperative treatments fail. However, a growing body of literature has been reporting suboptimal outcomes following TKA and THA. While pre- and post-operative rehabilitation is imperative to recovery, little is known about their effectiveness for patients at risk of poor outcomes. In the 2 systematic reviews with identical methodology, we aim to evaluate the effectiveness of (a) pre-operative and (b) post-operative rehabilitation interventions for patients at risk of poor outcomes following TKA and THA.

Methods

The 2 systematic reviews will follow the principles and recommendations outlined in the Cochrane Handbook. Only randomized controlled trials (RCTs) and pilot RCTs will be searched in 6 databases: CINAHL, MEDLINE, Embase, Web of Science, Pedro, and OTseeker. Eligible studies including patients at risk of poor outcomes and evaluating rehabilitation interventions following and preceding arthroplasty will be considered for inclusion. Primary outcomes will include performance-based tests and functional patient-reported outcome measures, and secondary outcomes will include health-related quality of life and pain. The quality of eligible RCTs will be evaluated using the Cochrane's risk of bias tool, and the strength of evidence will be assessed using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE).

Discussion

These reviews will synthesize the evidence regarding the effectiveness of pre-and post-operative rehabilitation interventions for patients at risk of poor outcomes, which in turn may inform practitioners and patients in planning and implementing the most optimal rehabilitation programs to achieve the best outcomes after arthroplasty.

Systematic Review Registration

PROSPERO CRD42022355574.

Preoperative Risk Management Programs at the Top 50 Orthopaedic Institutions Frequently Enforce Strict Cutoffs for BMI and Hemoglobin A1c Which May Limit Access to Total Joint Arthroplasty and Provide Limited Resources for Smoking Cessation and Dental Care

BACKGROUND

Performing elective orthopaedic surgery on patients with high BMI, poorly controlled hyperglycemia, and who use tobacco can lead to serious complications. Some surgeons use cutoffs for BMI, hemoglobin A1c, and cigarette smoking to limit surgery to patients with lower risk profiles rather than engaging in shared decision-making with patients about those factors. Other studies have suggested this practice may discriminate against people of lower income levels and women. However, the extent to which this practice approach is used by orthopaedic surgeons at leading hospitals is unknown.

QUESTIONS/PURPOSES

(1) How often are preoperative cutoffs for hemoglobin A1c and BMI used at the top US orthopaedic institutions? (2) What services are available at the top orthopaedic institutions for weight loss, smoking cessation, and dental care? (3) What proportion of hospital-provided weight loss clinics, smoking cessation programs, and dental care clinics accept Medicaid insurance?

METHODS

To investigate preoperative cutoffs for hemoglobin A1c and BMI and patient access to nonorthopaedic specialists at the top orthopaedic hospitals in the United States, we collected data on the top 50 orthopaedic hospitals in the United States as ranked by the 2020 US News and World Report 's "Best Hospitals for Orthopedics" list. We used a surgeon-targeted email survey to ascertain information regarding the use of preoperative cutoffs for hemoglobin A1c and BMI and availability and insurance acceptance policies of weight loss and dental clinics. Surgeons were informed that the survey was designed to assess how their institution manages preoperative risk management. The survey was sent to one practicing arthroplasty surgeon, the chair of the arthroplasty service, or department chair, whenever possible, at the top 50 orthopaedic institutions. Reminder emails were sent periodically to encourage participation from nonresponding institutions. We received survey responses from 70% (35 of 50) of hospitals regarding the use of preoperative hemoglobin A1c and BMI cutoffs. There was no difference in the response rate based on hospital ranking or hospital region. Fewer responses were received regarding the availability and Medicaid acceptance of weight loss and dental clinics. We used a "secret shopper" methodology (defined as when a researcher calls a facility pretending to be a patient seeking care) to gather information from hospitals directly. The use of deception in this study was approved by our institution's institutional review board. We called the main telephone line at each institution and spoke with the telephone operator at each hospital asking standardized questions regarding the availability of medical or surgical weight loss clinics, smoking cessation programs, and dental clinics. When possible, researchers were referred directly to the relevant departments and asked phone receptionists if the clinic accepted Medicaid. We were able to contact every hospital using the main telephone number. Our first research question was answered using solely the surgeon survey responses. Our second and third research questions were addressed using a combination of the responses to the surgeon surveys and specific hospital telephone calls.

RESULTS

Preoperative hemoglobin A1c cutoffs were used at 77% (27 of 35) of responding institutions and preoperative BMI cutoffs were used at 54% (19 of 35) of responding institutions. In the secret shopper portion of our study, we found that almost all the institutions (98% [49 of 50]) had a medical weight loss clinic, surgical weight loss clinic, or combined program. Regarding smoking cessation, 52% (26 of 50) referred patients to a specific department in their institution and 18% (9 of 50) referred to a state-run smoking cessation hotline. Thirty percent (15 of 50) did not offer any internal resource or external referral for smoking cessation. Regarding dental care, 48% (24 of 50) of institutions had a dental clinic that performed presurgical check-ups and 46% (23 of 50) did not offer any internal resource or external referral for dental care. In the secret shopper portion of our study, for institutions that had internal resources, we found that 86% (42 of 49) of weight loss clinics, 88% (23 of 26) of smoking cessation programs, and 58% (14 of 24) of dental clinics accepted Medicaid insurance.

CONCLUSION

Proceeding with TJA may not be the best option for all patients; however, surgeons and patients should come to this consensus together after a thoughtful discussion of the risks and benefits for that particular patient. Future research should focus on how shared decision-making may influence patient satisfaction and a patient's ability to meet preoperative goals related to weight loss, glycemic control, smoking cessation, and dental care. Decision analyses or time trade-off analyses could be implemented in these studies to assess patients' tolerance for risk.

CLINICAL RELEVANCE

Orthopaedic surgeons should engage in shared decision-making with patients to develop realistic goals for weight loss, glycemic control, smoking cessation, and dental care that consider patient access to these services as well as the difficulties patients experience in losing weight, controlling blood glucose, and stopping smoking.

Impact of Chronic Obstructive Pulmonary Disease on Outcomes After Total Joint Arthroplasty: A Meta-analysis and Systematic Review

Background

Comorbid chronic obstructive pulmonary disease (COPD) is increasingly common and may have an adverse impact on outcomes in patients undergoing total joint arthroplasty (TJA) of lower extremity. The purpose of this meta-analysis is to compare the postoperative complications between COPD and non-COPD patients undergoing primary TJA including total hip and knee arthroplasty.

Methods

PubMed, EMBASE, and Cochrane Library were systematically searched for relevant studies published before December 2021. Postoperative outcomes were compared between patients with COPD versus those without COPD as controls. The outcomes were mortality, re-admission, pulmonary, cardiac, renal, thromboembolic complications, surgical site infection (SSI), periprosthetic joint infection (PJI), and sepsis.

Results

A total of 1,002,779 patients from nine studies were finally included in this meta-analysis. Patients with COPD had an increased risk of mortality (OR [odds ratio] = 1.69, 95% confidence interval [CI] 1.42-2.02), re-admission (OR = 1.54, 95% CI 1.38-1.71), pulmonary complications (OR = 2.73, 95% CI 2.26-3.30), cardiac complications (OR = 1.40, 95% CI 1.15-1.69), thromboembolic complications (OR = 1.21, 95% CI 1.15-1.28), renal complications (OR = 1.50, 95% CI 1.14-1.26), SSI (OR = 1.23, 95% CI 1.18-1.30), PJI (OR = 1.26, 95% CI 1.15-1.38), and sepsis (OR = 1.36, 95% CI 1.22-1.52).

Conclusion

Patients with comorbid COPD showed an increased risk of mortality and postoperative complications following TJA compared with patients without COPD. Therefore, orthopedic surgeons can use the study to adequately educate these potential complications when obtaining informed consent. Furthermore, preoperative evaluation and medical optimization are crucial to minimizing postoperative complications from arising in this difficult-to-treat population.

Level of evidence

Level III.

Registration

None.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-022-00794-2.

Risk Factors for Nonresilient Outcomes in Older Adults After Total Knee Replacement

BACKGROUND

Total knee replacement (TKR) is a common procedure in older adults. Physical resilience may be a useful construct to explain variable outcomes. We sought to define a simple measure of physical resilience and identify risk factors for nonresilient patient outcomes.

METHODS

Secondary analysis of Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement (FORCE-TJR) cohort study, a prospective registry of total joint replacement. The analysis included 7 239 adults aged 60 or older who underwent TKR between 2011 and 2015. Measures included sociodemographic and health factors. Outcomes were categorized as physically resilient versus nonresilient based on the change from baseline to 1-year follow-up for 3 patient-reported outcomes: the physical component summary (PCS), bodily pain (BP), and vitality (VT) from the Short Form-36 subcomponent scores, at preop and 1-year postprocedure. Associations were expressed as relative risk (RR) of physically nonresilient outcomes using generalized linear regression models, with Poisson distribution and log link.

RESULTS

Age, body mass index, and Charlson Comorbidity Index (CCI) were associated with increased risk of physically nonresilient outcomes across PCS, BP, and VT: age, per 5 years for PCS (RR = 1.18 [1.12-1.23]), BP (RR = 1.06 [1.01-1.11), and VT (RR = 1.09 [1.06-1.12]); body mass index, per 5 kg/m2, for PCS (RR = 1.13 [1.07-1.19]), BP (RR = 1.06 [1.00-1.11]), and VT (RR = 1.08 [1.04-1.11]); and CCI for PCS CCI = 1 (RR = 1.38 [1.20-1.59]), CCI = 2-5 (RR = 1.59 [1.35-1.88]), CCI ≥6 (RR = 1.55 [1.31-1.83]. Household income >$45 000 associated with lower risk for PCS (RR = 0.81 [0.70-0.93]), BP (RR = 0.80 [0.69-0.91]), and VT (RR = 0.86 [0.78-0.93]).

CONCLUSIONS

We operationalized physical resilience and identified factors predicting resilience after TKR. This approach may aid clinical risk stratification, guide further investigation of causes, and ultimately aid patients through the design of interventions to enhance physical resilience.

Development of prediction models for complications after primary total hip and knee arthroplasty: a single-centre retrospective cohort study in the Netherlands

OBJECTIVE

The aim of this study was to develop prediction models for patients with total hip arthroplasty (THA) and total knee arthroplasty (TKA) to predict the risk for surgical complications based on personal factors, comorbidities and medication use.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care in outpatient clinic of university medical centre.

PARTICIPANTS

3776 patients with a primary THA or TKA between 2004 and 2018.

PRIMARY AND SECONDARY OUTCOME MEASURES

Multivariable logistic regression models were developed for primary outcome surgical site infection (SSI), and secondary outcomes venous thromboembolism (VTE), postoperative bleeding (POB), luxation, delirium and nerve damage (NER).

RESULTS

For SSI, age, smoking status, body mass index, presence of immunological disorder, diabetes mellitus, liver disease and use of non-steroidal anti-inflammatory drugs were included. An area under the receiver operating characteristic curve (AUC) of 71.9% (95% CI=69.4% to 74.4%) was found. For this model, liver disease showed to be the strongest predictor with an OR of 10.7 (95% CI=2.4 to 46.6). The models for POB and NER showed AUCs of 73.0% (95% CI=70.7% to 75.4%) and 76.6% (95% CI=73.2% to 80.0%), respectively. For delirium an AUC of 85.9% (95% CI=83.8% to 87.9%) was found, and for the predictive algorithms for luxation and VTE we found least favourable results (AUC=58.4% (95% CI=55.0% to 61.8%) and AUC=66.3% (95% CI=62.7% to 69.9%)).

CONCLUSIONS

Discriminative ability was reasonable for SSI and predicted probabilities ranged from 0.01% to 51.0%. We expect this to enhance shared decision-making in considering THA or TKA since current counselling is predicated on population-based probability of risk, rather than using personalised prediction. We consider our models for SSI, delirium and NER appropriate for clinical use when taking underestimation and overestimation of predicted risk into account. For VTE and POB, caution concerning overestimation exceeding a predicted probability of 0.08 for VTE and 0.05 for POB should be taken into account. Furthermore, future studies should evaluate clinical impact and whether the models are feasible in an external population.

Effects of Comorbidities on Pain and Function After Total Hip Arthroplasty

Background

The growing number of patients undergoing total hip arthroplasty (THA) and postoperative outcomes receive increasing attention from doctors and patients. This study aimed to elucidate the effects of comorbidities on postoperative function, pain, complications, readmission rate, and mortality.

Methods

We included consecutive patients who underwent primary unilateral THA between 2017 and 2019. The Charlson comorbidity index (CCI) and the WOMAC and SF-36 (physical function, body pain) scales were assessed preoperatively and at 3, 6, 12, and 24 months postoperatively. The complications, 30-day readmission, and mortality rates assessed the impact of comorbidities and their changes over time on the WOMAC and SF-36 scores during follow-up. We used mixed model linear regression to examine the association of worsening comorbidity post-THA with change in WOMAC and SF-36 scores in the subsequent follow-up periods, controlling for age, length of follow-up, and repeated observations.

Results

This study included 468 patients, divided into four groups based on comorbidity burden (CCI-0, 1, 2, and ≥3). The physiological function recovery and pain scores in the CCI ≥ 3 group were inferior to the other groups and took longer than the other groups (6 vs. 3 months) to reach their best level. The four groups preoperative waiting times were 2.41 ± 0.74, 2.97 ± 0.65, 3.80 ± 0.53, and 5.01 ± 0.71 days, respectively. The complications, 30-day readmission, and 1-year mortality rates for the overall and the CCI ≥ 3 group were 1.92% and 4.69%, 0.85% and 2.01%, and 0.43% and 1.34%, respectively, with no mortality in the other groups.

Conclusion

Patients with higher CCI were more susceptible to physical function and pain outcome deterioration, experienced longer waiting time before surgery, took longer to recover, and had higher rates of complications, 30-day readmission, and mortality after THA. Older age in the group led to a greater impact.

What Can We Learn From Surgeons Who Perform THA and TKA and Have the Lowest Revision Rates? A Study from the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

Long-term implant survivorship in THA and TKA involves a combination of factors related to the patient, the implants used, and the decision-making and technical performance of the surgeon. It is unclear which of these factors is the most important in reducing the proportion of revision surgery.

QUESTIONS/PURPOSES

We used data from a large national registry to ask: In patients receiving primary THA and TKA for a diagnosis of osteoarthritis, do (1) the reasons for revision and (2) patient factors, the implants used, and the surgeon or surgical factors differ between surgeons performing THA and TKA who have a lower revision rate compared with all other surgeons?

METHODS

Data were analyzed for all THA and TKA procedures performed for a diagnosis of osteoarthritis from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from September 1, 1999, when collection began, to December 31, 2018. The AOANJRR obtains data on more than 98% of joint arthroplasties performed in Australia. The 5-year cumulative percent revision (CPR) was identified for all THAs and TKAs performed for a diagnosis of osteoarthritis with 95% confidence intervals (overall CPR); the 5-year CPR with 95% CIs for each surgeon was calculated for THA and TKA separately. For surgeons to be included in the analysis, they had to have performed at least 50 procedures and have a 5-year CPR. The 5-year CPR with 95% CIs for each THA and TKA surgeon was compared with the overall CPR. Two groups were defined: low revision rate surgeons (the upper confidence level for a given surgeon at 5 years is less than 3.84% for THA and 4.32% for TKA), and all other surgeons (any surgeon whose CPR was higher than those thresholds). The thresholds were determined by setting a cutoff at 20% above the upper confidence level for that class. The approach we used to define a low revision rate surgeon was similar to that used by the AOANJRR for determining the better-performing prostheses and is recommended by the International Prosthesis Benchmarking Working Group. By defining the groups in this way, a significant difference between these two groups is created. Determining a reason for this difference is the purpose of presenting the proportions of different factors within each group. The study group for THA included 116 low revision rate surgeons, who performed 88,392 procedures (1619 revised, 10-year CPR 2.7% [95% CI 2.6% to 2.9%]) and 433 other surgeons, who performed 170,094 procedures (6911 revised, 10-year CPR 5.9% [95% CI 5.7% to 6.0%]). The study group for TKA consisted of 144 low revision rate surgeons, who performed 159,961 procedures (2722 revised, 10-year CPR 2.6% [95% CI 2.5% to 2.8%]) and 534 other surgeons, who performed 287,232 procedures (12,617 revised, 10-year CPR 6.4% [95% CI 6.3% to 6.6%]). These groups were defined a priori by their rate of revision, and the purpose of this study was to explore potential reasons for this observed difference.

RESULTS

For THA, the difference in overall revision rate between low revision rate surgeons and other surgeons was driven mainly by fewer revisions for dislocation, followed by component loosening and fracture in patients treated by low revision rate surgeons. For TKA, the difference in overall revision rate between low revision rate surgeons and other surgeons was driven mainly by fewer revisions for aseptic loosening, followed by instability and patellofemoral complications in patients treated by low revision rate surgeons. Patient-related factors were generally similar between low revision rate surgeons and other surgeons for both THA and TKA. Regarding THA, there were differences in implant factors, with low revision rate surgeons using fewer types of implants that have been identified as having a higher-than-anticipated rate of revision within the AOANJRR. Low revision rate surgeons used a higher proportion of hybrid fixation, although cementless fixation remained the most common choice. For surgeon factors, low revision rate surgeons were more likely to perform more than 100 THA procedures per year, while other surgeons were more likely to perform fewer than 50 THA procedures per year. In general, the groups of surgeons (low revision rate surgeons and other surgeons) differed less in terms of years of surgical experience than they did in terms of the number of cases they performed each year, although low revision rate surgeons, on average, had more years of experience and performed more cases per year. Regarding TKA, there were more differences in implant factors than with THA, with low revision rate surgeons more frequently performing patellar resurfacing, using an AOANJRR-identified best-performing prosthesis combination (with the lowest rates of revision), using fewer implants that have been identified as having a higher-than-anticipated rate of revision within the AOANJRR, using highly crosslinked polyethylene, and using a higher proportion of cemented fixation compared with other surgeons. For surgeon factors, low revision rate surgeons were more likely to perform more than 100 TKA procedures per year, whereas all other surgeons were more likely to perform fewer than 50 procedures per year. Again, generally, the groups of surgeons (low revision rate surgeons and other surgeons) differed less in terms of years of surgical experience than they did in terms of the number of cases they performed annually, although low revision rate surgeons, on average, had more years of experience and performed more cases per year.

CONCLUSION

THAs and TKAs performed by surgeons with the lowest revision rates in Australia show reductions in all of the leading causes of revision for both THA and TKA, in particular, causes of revision related to the technical performance of these procedures. Patient factors were similar between low revision rate surgeons and all other surgeons for both THA and TKA. Low revision rate THA surgeons were more likely to use cement fixation selectively. Low revision rate TKA surgeons were more likely to use patella resurfacing, crosslinked polyethylene, and cemented fixation. Low revision rate THA and TKA surgeons were more likely to use an AOANJRR-identified best-performing prosthesis combination and to use fewer implants identified by the AOANJRR as having a higher-than-anticipated revision rate. To reduce the rate of revision THA and TKA, surgeons should consider addressing modifiable factors related to implant selection. Future research should identify surgeon factors beyond annual case volume that are important to improving implant survivorship.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Death after surgery among patients with chronic disease: prospective study of routinely collected data in the English NHS

BACKGROUND

Five million surgeries take place in the NHS each year. Little is known about the prevalence of chronic diseases among these patients, and the association with postoperative outcomes.

METHODS

Analysis of routine data from all NHS hospitals in England including patients aged ≥18 yr undergoing non-obstetric surgery between January 1, 2010 and December 31, 2015. The primary outcome was death within 90 days after surgery. For each chronic disease, we adjusted for age, sex, presence of other diseases, emergency surgery, and year using logistic regression models. We defined high-risk diseases as those with an adjusted odds ratio (OR) for death ≥2 and report associated 2-yr survival.

RESULTS

We included 8 624 611 patients (median age, 53 [36-68] yr), of whom 6 913 451 (80.2%) underwent elective surgery and 1 711 160 (19.8%) emergency surgery. Overall, 2 311 600 (26.8%) patients had a chronic disease, of whom 109 686 (4.7%) died within 90 days compared with 24 136 (0.4%) of 6 313 011 without chronic disease. Respiratory disease (1 002 281 [11.6%]), diabetes mellitus (662 706 [7.7%]), and cancer (310 363; 3.6%) were the most common. Four chronic diseases accounted for 7.7% of patients but 59.0% of deaths: cancer (37 693 deaths [12.1%]; OR=8.3 [8.2-8.5]), liver disease (8638 deaths [10.3%]; OR=4.5 [4.4-4.7]), cardiac failure (26 604 deaths [12.6%]; OR=2.4 [2.4-2.5]), and dementia (19 912 deaths [17.9%]; OR=2.0 [1.9-2.0]). Two-year survival was 67.7% among patients with high-risk chronic disease, compared with 97.1% without.

CONCLUSION

One in four surgical patients has a chronic disease with an associated 10-fold increase in risk of postoperative death. Two-thirds of all deaths after surgery occur among patients with high-risk diseases (cancer, cardiac failure, liver disease, dementia).

Fatal outcome and intensive care unit admission after total hip and knee arthroplasty: An analytic of preoperative frailty and comorbidities

BACKGROUND

With increasing demand for total hip arthroplasty (THA) and total knee arthroplasty (TKA), a higher percentage of patients are identified with comorbidities that might increase the risk of complications. We aimed to elucidate the preoperative characteristics of patients with a fatal outcome or admission to the Intensive Care Unit (ICU) within 90 days after THA or TKA. We arbitrarily hypothesized that more than 50% of those patients would be frail.

METHODS

This is a register based, explorative study including patients undergoing elective, unilateral, primary THA or TKA in the Capital Region of Denmark from 2010 to 2017, and who subsequently died or were admitted to the ICU within 90 days. The modified Frailty Index (mFI) was calculated from the medical records, and a score of ≥0.36 defined frailty.

RESULTS

A total of 33,758 patients underwent THA or TKA, and 284 patients (0.8%) died or were admitted to the ICU within 90 days. Fifty-seven patients (20%) were frail (95% CI 16.2-25.7%). The most common comorbidities were hypertension (63%) and pulmonary diseases (32%), and 56% used walking aids. Two or more comorbidities were present in 65% of patients, and 14% had no comorbidities at all.

CONCLUSION

Only 20% of patients with a fatal outcome or ICU admission after elective THA or TKA could be categorized as frail based on the mFI. Further studies with a prospective design are needed to clarify the mFI as a risk stratification tool in elderly multimorbid patients undergoing elective arthroplasty surgery.

Clinical Practice Guideline: Total Hip Replacement for Osteoarthritis–Evidence-Based and Patient-Oriented Indications

BACKGROUND

Total Hip Replacement (THR) belongs to the most common inpatient operations in Germany, with over 240 000 procedures performed per year. 90% of the artificial joints are still functional at 15 years, and up to 60% at 20 years after surgery. It is essential that the indications for such procedures should be uniform, appropriate, and patient-oriented.

METHODS

This review is based on publications retrieved by a systematic literature search for national and international guidelines and systematic reviews on the topic of hip osteoarthritis and THR.

RESULTS

THR should be performed solely with radiologically demonstrated advanced osteoarthritis of the hip (Kellgren and Lawrence grade 3 or 4), after at least three months of conservative treatment, and in the presence of high subjective distress due to symptoms arising from the affected hip joint. Contraindications include refractory infection, acute or chronic accompanying illnesses, and BMI ≥ 40 kg/m2. Patients should stop smoking at least one month before surgery. In patients with diabetes mellitus, preoperative glycemic control to an HbA1c value below 8% is advisable. It is recommended that patients should lower their weight below a BMI of 30 kg/m2.

CONCLUSION

The decision to perform THR should be taken together by both the physician and the patient when the expected treatment benefit outweighs the risks. Evidence suggests that a worse preoperative condition is associated with a poorer surgical outcome.

Effects of Sarcopenic Obesity and Its Confounders on Knee Range of Motion Outcome after Total Knee Replacement in Older Adults with Knee Osteoarthritis: A Retrospective Study

Sarcopenic obesity is closely associated with knee osteoarthritis (KOA) and has high risk of total knee replacement (TKR). In addition, poor nutrition status may lead to sarcopenia and physical frailty in KOA and is negatively associated with surgery outcome after TKR. This study investigated the effects of sarcopenic obesity and its confounding factors on recovery in range of motion (ROM) after total knee replacement (TKR) in older adults with KOA. A total of 587 older adults, aged ≥60 years, who had a diagnosis of KOA and underwent TKR, were enrolled in this retrospective cohort study. Sarcopenia and obesity were defined based on cutoff values of appendicular mass index and body mass index for Asian people. Based on the sarcopenia and obesity definitions, patients were classified into three body-composition groups before TKR: sarcopenic-obese, obese, and non-obese. All patients were asked to attend postoperative outpatient follow-up admissions. Knee flexion ROM was measured before and after surgery. A ROM cutoff of 125 degrees was used to identify poor recovery post-surgery. Kaplan-Meier curve analysis was performed to measure the probability of poor ROM recovery among study groups. Cox multivariate regression models were established to calculate the hazard ratios (HRs) of postoperative poor ROM recovery, using potential confounding factors including age, sex, comorbidity, risk of malnutrition, preoperative ROM, and outpatient follow-up duration as covariates. Analyses results showed that patients in the obese and sarcopenic-obese groups had a higher probability of poor ROM recovery compared to the non-obese group (all p < 0.001). Among all body-composition groups, the sarcopenic-obese group yielded the highest risk of postoperative physical difficulty (adjusted HR = 1.63, p = 0.03), independent to the potential confounding factors. Sarcopenic obesity is likely at the high risk of poor ROM outcome following TKR in older individuals with KOA.

[Rehabilitation following total knee replacement]

BACKGROUND

Total knee replacement requires follow-up treatment. This can take place on an outpatient basis as part of health insurance coverage, but also as outpatient or inpatient rehabilitation.

KIND OF REHABILITATION

Outpatient rehabilitation provides comparable results to inpatient rehabilitation, but only for those patients who are suitable for outpatient rehabilitation. Inpatient rehabilitation should be indicated depending on general health status, general physical fitness, housing situation, accessibility of rehabilitation facilities and possibilities of social support in the home environment, as well as age and comorbidities. Physiotherapeutic procedures should focus on exercise therapy. Passive reactive measures complement the therapy. For patients of working age, the activity profile should be considered as part of the rehabilitation process. Patient education, with information on prosthesis-appropriate behavior, represents an important component in follow-up treatment.

PROSPECT

Demographic change requires increasing consideration of orthogeriatric aspects. Fast-track programs will not make follow-up treatment superfluous, but with accelerated processes they represent a new challenge for sectoral cooperation.

Does a Prescription-based Comorbidity Index Correlate with the American Society of Anesthesiologists Physical Status Score and Mortality After Joint Arthroplasty? A Registry Study

BACKGROUND

When analyzing the outcomes of joint arthroplasty, an important factor to consider is patient comorbidities. The presence of multiple comorbidities has been associated with longer hospital stays, more postoperative complications, and increased mortality. The American Society of Anesthesiologists (ASA) physical status classification system score is a measure of a patient's overall health and has been shown to be associated with complications and mortality after joint arthroplasty. The Rx-Risk score is another measure for determining the number of different health conditions for which an individual is treated, with a possible score ranging from 0 to 47.

QUESTIONS/PURPOSES

For patients undergoing THA or TKA, we asked: (1) Which metric, the Rx-Risk score or the ASA score, correlates more closely with 30- and 90-day mortality after TKA or THA? (2) Is the Rx-Risk score correlated with the ASA score?

METHODS

This was a retrospective analysis of the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) database linked to two other national databases, the National Death Index (NDI) database and the Pharmaceutical Benefits Scheme (PBS), a dispensing database. Linkage to the NDI provided outcome information on patient death, including the fact of and date of death. Linkage to the PBS was performed to obtain records of all medicines dispensed to patients undergoing a joint replacement procedure. Patients were included if they had undergone either a THA (119,076 patients, 131,336 procedures) or TKA (182,445 patients, 215,712 procedures) with a primary diagnosis of osteoarthritis, performed between 2013 and 2017. We excluded patients with missing ASA information (THA: 3% [3055 of 119,076]; TKA: 2% [4095 of 182,445]). This left 127,761 primary THA procedures performed in 116,021 patients (53% [68,037 of 127,761] were women, mean age 68 ± 11 years) and 210,501 TKA procedures performed in 178,350 patients (56% [117,337 of 210,501] were women, mean age 68 ± 9 years) included in this study. Logistic regression models were used to determine the concordance of the ASA and Rx-Risk scores and 30-day and 90-day postoperative mortality. The Spearman correlation coefficient (r) was used to estimate the correlation between the ASA score and Rx-Risk score. All analyses were performed separately for THAs and TKAs.

RESULTS

We found both the ASA and Rx-Risk scores had high concordance with 30-day mortality after THA (ASA: c-statistic 0.83 [95% CI 0.79 to 0.86]; Rx-Risk: c-statistic 0.82 [95% CI 0.79 to 0.86]) and TKA (ASA: c-statistic 0.73 [95% CI 0.69 to 0.78]; Rx-Risk: c-statistic 0.74 [95% CI 0.70 to 0.79]). Although both scores were strongly associated with death, their correlation was moderate for patients undergoing THA (r = 0.45) and weak for TKA (r = 0.38). However, the median Rx-Risk score did increase with increasing ASA score. For example, for THAs, the median Rx-Risk score was 1, 3, 5, and 7 for ASA scores 1, 2, 3, and 4, respectively. For TKAs, the median Rx-Risk score was 2, 4, 5, and 7 for ASA scores 1, 2, 3, and 4, respectively.

CONCLUSION

The ASA physical status and RxRisk were associated with 30-day and 90-day mortality; however, the scores were only weakly to moderately correlated with each other. This suggests that although both scores capture a similar level of patient illness, each score may be capturing different aspects of health. The Rx-Risk may be used as a complementary measure to the ASA score.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Does Increasing Patient Complexity Have an Effect on Medical Outcomes and Lengths-of-Stay after Total Knee Arthroplasty?

A greater number of medically complex patients with multiple comorbidities are now more readily considered for total knee arthroplasty (TKA). Therefore, the purpose of this study was to determine whether comorbidity burden, measured with the Elixhauser Comorbidity Index (ECI), correlated with 90-day medical complications and longer in-hospital lengths-of-stay (LOS) in TKA patients. The PearlDiver supercomputer was queried for all primary TKA patients in the Medicare Standard Analytic Files from 2005 to 2014 using International Classification of Disease, 9th edition codes. Patients were included based on ECI scores, ranging from 1 to 5. ECI 1 patients served as the control cohort, while ECI 2, 3, 4, and 5 patients were considered study cohorts. Each study cohort was matched based on age and gender to the control cohort, resulting in a total of 715,398 patients included for analysis (ECI 1, n = 144,072; ECI 2, n = 144,072; ECI 3, n = 144,072; ECI 4, n = 144,072; ECI 5, n = 139,110). Logistic regression analyses were performed to compare 90-day medical complications and Welch's t-tests were performed to compare LOS between the cohorts. Patients with higher ECI scores were more likely to develop medical complications and have longer LOS compared with matched patients in the control cohort. Compared with matched ECI 1 patients, patients with ECI scores of 2 (odds ratio [OR]: 1.19, 95% confidence interval [CI]: 1.14-1.24), 3 (OR: 1.27, 95% CI: 1.21-1.32), 4 (OR: 1.32, 95% CI: 1.27-1.38), and 5 (OR: 1.33, 95% CI: 1.27-1.39) were significantly more likely to develop 90-day medical complications. Additionally, the mean LOS of patients in the ECI 2 (2.59 ± 1.49 vs. 2.73 ± 1.52 days), ECI 3 (2.59 ± 1.49 vs. 2.88 ± 1.51 days; p < 0.001), ECI 4 (2.59 ± 1.49 vs. 3.01 ± 1.56 days; p < 0.001), and ECI 5 (2.61 ± 1.49 vs. 3.14 ± 1.61 days; p < 0.001) groups were significantly longer than the mean LOS in the control ECI 1 group. In an increasingly complex patient population, associations between comorbidities and outcomes after TKA procedures can guide providers on how to modify their pre- and postoperative care. These results demonstrate that higher ECI scores are associated with a greater likelihood of 90-day medical complications and longer in-hospital LOS.

The Hospital Frailty Risk Score is Not an Accurate Predictor of Treatment Costs for Total Joint Replacement Patients in a Medicare Bundled Payment Population

BACKGROUND

Medically complex patients require more resources and experience higher costs within total joint arthroplasty (TJA) bundled payment models. While risk adjustment would be beneficial for such patients, no tool currently exists which can reliably identify these patients preoperatively. The purpose of this study is to determine if the Hospital Frailty Risk Score (HFRS) is a valid predictor of high-TJA treatment costs.

METHODS

Retrospective analysis was performed on patients who underwent primary TJA between 2015 and 2020 from a single large orthopedic practice. ICD-10 codes from an institutional database were used to calculate HFRS. Cost data including inpatient, postacute, and episode of care (EOC) costs were collected. Charlson comorbidity index, demographics, readmissions, and complications were analyzed.

RESULTS

4936 patients had a calculable HFRS and those with intermediate and high scores experienced more frequent readmissions/complications after TJA, as well as higher EOC costs. However, HFRS did not reliably predict EOC costs, yielding a sensitivity of 49% and specificity of 66%. Multivariate analysis revealed that both patient age and sex are superior individual cost predictors when compared with HFRS. Secondary analyses indicated that HFRS more effectively predicts TJA complications and readmissions but is still nonideal for clinical applications.

CONCLUSION

HFRS has poor sensitivity as a predictor of high-EOC costs for TJA patients but has adequate specificity for predicting postoperative readmissions and complications. Further research is needed to develop a scale that can appropriately predict orthopedic cost outcomes.