A Cost Analysis of Surgical Approach in Total Hip Arthroplasty

BACKGROUND

With pressures to decrease the financial burden of total hip arthroplasty (THA), it is imperative to understand the cost drivers of this procedure. This study evaluated operative and total encounter costs for two surgical approaches to THA-posterior (P) and direct anterior (DA).

MATERIALS AND METHODS

A total of 233 THAs (134 P and 99 DA) performed by two fellowship-trained arthroplasty surgeons from 2017 to 2022 were reviewed. Demographics, comorbidities, mobility status, operative time, length of stay, implants used, discharge location, and complications until final follow-up were recorded. Total encounter cost was collected and itemized. Multivariable regression analyses evaluated predictors of cost.

RESULTS

There were differences in age (67 years for DA and 63 years for P; P=.03), body mass index (28.0 kg/m2 for DA and 33.8 kg/m2 for P; P<.01), Elixhauser Comorbidity Index score (4.6 for DA and 5.6 for P; P=.04), and operative time (2.1 hours for DA and 1.9 hours for P; P<.01) between the two cohorts. The DA cohort trended toward shorter length of stay, with the highest percentage of patients discharged home (86.9%; P=.02). The P cohort had the lowest encounter ($9601 for DA and $9100 for P; P=.20) and intraoperative (including implant used) ($7268 for DA and $6792 for P; P<.01) costs. The DA cohort had a significantly higher cost of radiology during the encounter ($244; P<.01). Regression analysis demonstrated that length of stay and DA approach were both predictors of increased encounter cost.

CONCLUSION

The DA cohort had improved measures of health; however, this approach was associated with a higher operative cost and was predictive of increased encounter cost despite a shorter length of stay. [Orthopedics. 2024;47(3):e151-e156.].

Developing a Computer Vision Model to Automate Quantitative Measurement of Hip-Knee-Ankle Angle in Total Hip and Knee Arthroplasty Patients

BACKGROUND

Increasing deformity of the lower extremities, as measured by the Hip-Knee-Ankle Angle (HKAA), is associated with poor patient outcomes after total hip and knee arthroplasty (THA, TKA). Automated calculation of HKAA is imperative to reduce the burden on orthopaedic surgeons. We proposed a detection-based deep learning (DL) model to calculate HKAA in THA and TKA patients and assessed the agreement between DL-derived HKAAs and manual measurement.

METHODS

We retrospectively identified 1,379 long-leg radiographs (LLR) from patients scheduled for THA or TKA within an academic medical center. There were 1,221 LLRs used to develop the model (randomly split into 70% training, 20% validation, and 10% held-out test sets); 158 LLRs were considered "difficult," as the femoral head was difficult to distinguish from surrounding tissue. There were two raters who annotated the HKAA of both lower extremities, and inter-rater reliability was calculated to compare the DL-derived HKAAs with manual measurement within the test set.

RESULTS

The DL model achieved a mean average precision of 0.985 on the test set. The average HKAA of the operative leg was 173.05 +/- 4.54°; the non-operative leg was 175.55 +/- 3.56°. The inter-rater reliability between manual and DL-derived HKAA measurements on the operative leg and non-operative leg indicated excellent reliability (Intraclass Correlation (ICC) (2,k) = 0.987 [0.96, 0.99], ICC (2,k) = 0.987 [0.98, 0.99, respectively]). The standard error of measurement for the DL-derived HKAA for the operative and non-operative legs was 0.515° and 0.403°, respectively.

CONCLUSION

A detection-based DL algorithm can calculate the HKAA in LLRs and is comparable to that calculated by manual measurement. The algorithm can detect the bilateral femoral head, knee, and ankle joints with high precision, even in patients where the femoral head is difficult to visualize.

The Removal of Total Knee Arthroplasty From the Inpatient-Only List has Improved Patient Optimization

INTRODUCTION

On January 1, 2018, the Centers for Medicare and Medicaid Services removed total knee arthroplasty (TKA) from the inpatient-only (IPO) list, expanding outpatient TKA (oTKA) to include patients with insurance coverage through their programs. These regulatory changes reinforced the need for preoperative optimization to ensure a safe and timely discharge after surgery. This study compared modifiable preoperative optimization metrics in patients who underwent oTKA pre-IPO and post-IPO removal. The authors hypothesized that patients post-IPO removal would demonstrate improvement in the selected categories.

METHODS

Outpatient TKA in a national database was identified and stratified by surgical year (2015 to 2017 versus 2018 to 2020). Preoperative optimization thresholds were established for the following modifiable risk factors: albumin, hematocrit, sodium, smoking, and body mass index. The percentage of patients who did not meet thresholds pre-IPO and post-IPO removal were compared.

RESULTS

In total, 2,074 patients underwent oTKA from 2015 to 2017 compared with 46,480 from 2018 to 2020. Patients undergoing oTKA after IPO removal were significantly older (67.0 versus 64.4 years; P < 0.01). A lower percentage of patients in the post-IPO cohort fell outside the threshold for all modifiable risk factors. Results were significant for preoperative sodium (10.7% versus 8.8%; P < 0.01), body mass index (12.4% versus 11.0% P = 0.05), and smoking history (9.9% versus 6.6%; P < 0.01).

CONCLUSION

Outpatient TKA has increased considerably post-IPO removal. As this regulatory change has allowed older patients with increased comorbidities to undergo oTKA, the need for appropriate preoperative optimization has increased. The current data set demonstrates that surgeons have improved preoperative optimization efforts for select modifiable risk factors.

Outcome Disparities in Total Knee and Total Hip Arthroplasty among Native American Populations

BACKGROUND

No prior racial disparities studies in total knee arthroplasty (TKA) and total hip arthroplasty (THA) have specifically evaluated outcomes among American Indian or Alaska Native (AIAN) patients. We hypothesized that AIAN patients have worse outcomes than White patients after controlling for demographics and comorbidities.

METHODS

This was a retrospective cohort study comparing White and AIAN patients undergoing primary TKA/THA from 2012-2019 using the American College of Surgeons National Surgical Quality Improvement Program. Race, demographics, and comorbidities were analyzed for correlations with 30-day outcomes and complications using multivariable logistic and linear regression analyses.

RESULTS

Comparing 422,215 White and 2,676 AIAN patients, AIAN patients had higher American Society of Anesthesiologist (ASA) classifications, body mass index (BMI), and were younger at the time of surgery. AIAN patients more often stayed inpatient > 2 days (49.4% vs 36.2%, p < 0.001), underwent reoperation (2.1% vs 1.4%, p < 0.01), and were discharged home (91.4% vs 81.7%, p < 0.01). Regression analyses controlling for age, BMI, sex, ASA classification, and functional status found that AIAN race was significantly positively correlated with a length of stay > 2 days (OR 1.6), reoperation (OR 1.4), and discharging home (OR 2.0).

CONCLUSION

AIAN patients undergoing TKA/THA present with a greater comorbidity burden compared to White patients and experience multiple worse outcome metrics including increased hospital length of stay and reoperation rates. Interestingly, AIAN patients were more likely to discharge home, representing a unique racial disparity which warrants further study.

Timing of Renal Transplant Prior to Total Knee Arthroplasty Impacts 90-Day Postoperative Outcomes

BACKGROUND

Renal transplant (RT) patients are at increased risk for complications after total knee arthroplasty (TKA); however, it is unknown if the time from RT to TKA influences such risks. This study evaluated RT patients undergoing primary TKA at various time intervals after transplant. We hypothesized that increased time between RT and TKA would decrease the risk of complications after TKA.

METHODS

There were 499 RT patients in a national database undergoing subsequent primary TKA from 2010 to 2020. Patients were stratified by intervals of less than 1 year, between 1 and 2 years, and more than 2 years from RT to TKA. Medical complications up to 90 days, readmissions, and 2-year revisions were compared via univariable and multivariable analyses.

RESULTS

Patients who underwent TKA less than 1 year after RT were associated with higher 90-day medical complications when compared to those who underwent TKA 1 to 2 years after RT (odds ratio [OR] 0.4, confidence interval [CI] 0.2 to 0.8, P = .01) and more than 2 years (OR 0.3, CI 0.2 to 0.7, P < .01) after RT. Acute kidney injury and blood transfusion were the most common complications. The TKAs performed 2 years after RT were less likely to have 90-day readmissions when compared to TKAs performed less than 1 year after RT (OR 0.4, CI: 0.2 to 0.9, P < .01). However, time from RT to TKA did not increase the risk of revision at 2 years (P > .30).

CONCLUSIONS

Patients undergoing TKA within 1 year of RT have an increased risk of 90-day postoperative medical complications and readmissions, but the time interval from RT does not appear to affect revision risk. These findings suggest waiting 1 year after RT before proceeding with TKA may be advantageous.

Utility of PROMIS Measures in Predicting Shoulder Arthroplasty in Patients with Shoulder Osteoarthritis

BACKGROUND

The decision to treat shoulder osteoarthritis definitively with shoulder arthroplasty (SA) is multifactorial, considering objective findings, subjective information, and patient goals. The first goal of this study was to determine if Patient Reported Outcome Measurement Information System (PROMIS) measures correlated with patients with shoulder osteoarthritis (OA) who underwent SA within 1 year. The second goal of this study was to determine if score cut-offs in PROMIS domains could further discriminate which shoulder OA patients underwent SA within 1 year.

METHODS

This retrospective case-control study examined patients with a diagnosis of shoulder OA who consulted an orthopedic provider from November 1, 2020, to May 23, 2022, and recorded PROMIS measures in the domains of Physical Function (PF), Depression, and/or Pain Interference (PI). A surgical group was defined as patients who underwent SA within 1 year of the most recent PROMIS measures, and the non-surgical patients were defined as the control group. Mean PROMIS scores were compared between the surgical and control groups. Separate logistic regression models controlling for age, race, ethnicity, and comorbidity count were performed for each PROMIS domain as a 1) continuous variable, then as 2) binary variable defined by PROMIS score cut-off points to determine which scores correlated with undergoing SA to further characterize the potential clinical utility of PROMIS score cut-offs in relating to undergoing SA.

RESULTS

The surgical group of 478 patients was older (68.2 vs. 63.8 years), more often of White race (82.6% vs. 70.9%), and less often of Hispanic Ethnicity (1.5% vs. 2.9%) than the control group of 3343 patients. Using optimal cut-offs in PROMIS scores, PI ≥ 63 (Odds Ratio (OR) = 2.97 (2.41-3.64), p < 0.001), PF ≤ 39 (OR = 1.81 (95% CI, 1.48-2.22), p < 0.001), and Depression ≥ 49 (OR = 1.82 (95% CI, 1.50-2.22), p < 0.001) were all found to correlate with undergoing SA within 1 year in multivariable logistic regressions.

CONCLUSION

The results of this study demonstrate that cut-off scores for PROMIS measures differentiated patients undergoing SA within 1 year. These cut-off scores may have clinical utility in aiding in decision-making regarding surgical candidates for SA. Further research is needed to validate these cut-off scores and determine how they relate to patient outcomes after SA.

The Posterior Approach is Associated With Lower Total Encounter and 90-Day Costs When Compared to the Direct Anterior Approach

BACKGROUND

The clinical impact of the surgical approach in total hip arthroplasty (THA) has been widely reviewed. This study evaluated the total encounter and 90-day costs of THA for 2 surgical approaches (posterior [P] and direct anterior [DA]) in 1 tertiary health system.

METHODS

This is a retrospective review of 2,101 THAs (1,092 P and 1,009 DA) by 4 surgeons (2 with the highest volume of DA and P, respectively) from 2017 to 2022 at 1 academic center. Demographics, comorbidities, operative time, length of hospital stay, 90-day hospital returns, and complications were compared. The total encounter cost and 90-day postoperative cost were itemized. Multivariable regression analyses evaluated associations with increased cost at each time point.

RESULTS

The DA cohort had a higher median encounter cost ($8,348.66 versus 7,332.42, P < .01), resulting from higher intraoperative (P < .01) and radiology (P < .01) expenses. Regression analyses demonstrated the DA was independently associated with increased encounter costs (odds ratio 1.1; 95% confidence interval 1.1 to 1.1; P < .01). There was a higher incidence of 90-day emergency department visits in the DA cohort (16 versus 12%, P = .02), with a trend toward increased readmissions. There was no difference in 90-day reoperations. Median 90-day cost was higher in the DA cohort ($126.99 versus 0.00, P < .01), and regression analyses demonstrated the DA had an association with increased 90-day cost (odds ratio 2.2; 95% confidence interval 1.5 to 3.0; P < .01).

CONCLUSIONS

Despite a younger patient population, the DA was independently associated with increased encounter and 90-day costs in a single academic hospital system. This study may underestimate the cost difference, as capital costs such as specialized tables were not analyzed.

Cementless Total Knee Arthroplasty: A Resurgence - Who, When, Where, and How?

BACKGROUND

Total knee arthroplasty (TKA) is one of the most common procedures in orthopaedics, but there is still debate over the optimal fixation method for long-term durability: cement versus cementless bone ingrowth. Recent improvements in implant materials and technology have offered the possibility of cementless TKA to change clinical practice with durable, stable biological fixation of the implants, improved operative efficiency, and optimal long-term results, particularly in younger and more active patients.

METHODS

This symposium evaluated the history of cementless TKA, the recent resurgence, and appropriate patient selection, as well as the historical and modern-generation outcomes of each implant (tibia, femur, and patella). Additionally, surgical technique pearls to assist in reliable, reproducible outcomes were detailed.

RESULTS

Historically, cemented fixation has been the gold standard for TKA. However, cementless fixation is increasing in prevalence in the United States and globally, with equivalent or improved results demonstrated in appropriately selected patients.

CONCLUSION

Cementless TKA provides durable biologic fixation and successful long-term results with improved operating room efficiency. Cementless TKA may be broadly utilized in appropriately selected patients, with intraoperative care taken to perform meticulous bone cuts to promote appropriate bony contact and biologic fixation.

Continuation of Oral Antidiabetic Medications Was Associated With Better Early Postoperative Blood Glucose Control Compared to Sliding Scale Insulin After Total Knee Arthroplasty

BACKGROUND

This study evaluated blood glucose (BG), creatinine levels, metabolic issues, length of stay (LOS), and early postoperative complications in diabetic primary total knee arthroplasty (TKA) patients. It examined those who continued home oral antidiabetic medications and those who switched to insulin postoperatively. The hypothesis was that continuing home medications would lead to lower BG levels without metabolic abnormalities.

METHODS

Patients who had diabetes who underwent primary TKA from 2013 to 2022 were evaluated retrospectively. Diabetic patients who were not on home oral antidiabetic medications or who were not managed as an inpatient postoperatively were excluded. Patient demographics and laboratory tests collected preoperatively and postoperatively as well as 90-day emergency department visits and 90-day readmissions, were pulled from electronic records. Patients were grouped based on inpatient diabetes management: continuation of home medications versus new insulin coverage. Acute postoperative BG control, creatinine levels, metabolic abnormalities, LOS, and early postoperative complications were compared between groups. Multivariable regression analyses were performed to measure associations.

RESULTS

A total of 867 primary TKAs were assessed; 703 (81.1%) patients continued their home oral antidiabetic medications. Continuing home antidiabetic medications demonstrated lower median maximum inpatient BG (180.0 mg/dL versus 250.0 mg/dL; P < .001) and median average inpatient BG (136.7 mg/dL versus 173.7 mg/dL; P < .001). Logistic regression analyses supported the presence of an association (odds ratio = 17.88 [8.66, 43.43]; P < .001). Proportions of acute kidney injury (13.5 versus 26.7%; P < .001) were also lower. There was no difference in relative proportions of metabolic acidosis (4.4 versus 3.7%; P = .831), LOS (2.0 versus 2.0 days; P = .259), or early postoperative complications.

CONCLUSIONS

Continuing home oral antidiabetic medications after primary TKA was associated with lower BG levels without an associated worsening creatinine or increase in metabolic acidosis.

LEVEL III EVIDENCE

Retrospective Cohort Study.

The Chitranjan S. Ranawat Award: Manipulation Under Anesthesia to Treat Postoperative Stiffness After Total Knee Arthroplasty: A Multicenter Randomized Clinical Trial

BACKGROUND

Manipulation under anesthesia (MUA) occurs in 4% of patients after total knee arthroplasty (TKA). Anti-inflammatory medications may target arthrofibrosis pathogenesis, but the data are limited. This multicenter randomized clinical trial investigated the effect of adjuvant anti-inflammatory medications with MUA and physical therapy on range of motion (ROM) and outcomes.

METHODS

There were 124 patients (124 TKAs) who developed stiffness after primary TKA for osteoarthritis enrolled across 15 institutions. All received MUA when ROM was < 90° at 4 to 12 weeks postoperatively. Randomization proceeded via a permuted block design. Controls received MUA and physical therapy, while the treatment group also received one dose of pre-MUA intravenous dexamethasone (8 mg) and 14 days of oral celecoxib (200 mg). The ROM and clinical outcomes were assessed at 6 weeks and 1 year. This trial was registered with ClinicalTrials.gov.

RESULTS

The ROM significantly improved a mean of 46° from a pre-MUA ROM of 72 to 118° immediately after MUA (P < .001). The ROM was similar between the treatment and control groups at 6 weeks following MUA (101 versus 99°, respectively; P = .35) and at one year following MUA (108 versus 108°, respectively; P = .98). Clinical outcomes were similar at both end points.

CONCLUSIONS

In this multicenter randomized clinical trial, the addition of intravenous dexamethasone and a short course of oral celecoxib after MUA did not improve ROM or outcomes. However, MUA provided a mean ROM improvement of 46° immediately, 28° at 6 weeks, and 37° at 1 year. Further investigation in regards to dosing, duration, and route of administration of anti-inflammatory medications remains warranted.

LEVEL OF EVIDENCE

Level 1, RCT.

Ultracongruent Polyethylene Liners Do Not Affect Survival of Total Knee Arthroplasty for Valgus Deformity

BACKGROUND

Valgus knee deformity is observed in nearly 10% of patients undergoing total knee arthroplasty (TKA). The degree of polyethylene constraint required to balance a valgus knee remains controversial, and historically, posterior-stabilized (PS) designs have been favored. This study evaluated the survivorship of TKA done in valgus knees based on implant design and specifically compared posterior-stabilized (PS) and ultracongruent (UC) liners.

METHODS

A total of 549 primary TKAs performed on valgus knees by fellowship-trained arthroplasty surgeons from 2013 to 2019 were reviewed. Demographics, comorbidities, degrees of preoperative deformity, implants used, and all-cause revisions until final follow-up were recorded. Cox regression analyses evaluated survival to all-cause revision in each cohort. The mean follow-up was 4.9 years (range, 2 to 9).

RESULTS

There were 403 UC liners compared to 146 PS liners. There was no difference in patient age (68 versus 67 years; P = .30), body mass index (30.9 versus 30.4; P = .36), or degree of deformity (8.6 versus 8.8 degrees; P = .75) between the cohorts. At final follow-up, there were 5 revisions in the PS cohort (3.4%) versus 11 revisions in the UC cohort (2.7%) (P = .90). The most common reason for revision in both cohorts was periprosthetic joint infection (4 PS; 8 UC). Multivariable regression analyses controlling for age, body mass index, Elixhauser comorbidity score, sex, and degree of deformity demonstrated UC polyethylene liners were not associated with revision (hazard ratio 0.76; 95% confidence interval [CI] 0.26 to 2.21; P = .62). There was no difference in eight-year survivorship to all-cause revision, including aseptic and septic failure.

CONCLUSIONS

Alternative polyethylene liners from the historically utilized PS liners for TKA for valgus deformity did not reduce survivorship. With modern polyethylene designs, UC inserts can be utilized for this deformity without increasing the risk of failure.

Does Medically Supervised Weight Loss Prior to Total Knee Arthroplasty Improve Patient-Reported Pain and Physical Function?

BACKGROUND

Weight loss is commonly recommended before total knee arthroplasty (TKA) despite inconsistent evidence for better outcomes. This study sought to examine the impacts of preoperative weight loss on patient-reported and adverse outcomes among TKA patients supervised by a medical weight management clinic.

METHODS

This study retrospectively analyzed patients who underwent medical weight management supervision within 18 months before TKA comparing patients who did and did not have clinically relevant weight loss. Preoperative body mass indices, demographics, Patient-Reported Outcomes Measurement Information System physical function and pain interference scores, pain intensity scores, and adverse outcomes were extracted. Multivariable linear regressions were performed to determine if preoperative weight loss correlated with patient-reported outcomes after controlling for confounders.

RESULTS

There were 90 patients, 75.6% women, who had a mean age of 65 years (range, 42-82) and were analyzed. There were 51 (56.7%) patients who underwent clinically relevant weight loss with a mean weight loss of 10.4% and experienced no difference in adverse outcomes. Preoperative weight loss predicted significantly improved 3-month postoperative physical function (β = 15.2 [13.0-17.3], P < .001), but not pain interference (β = -18.9 [-57.1-19.4], P = .215) or pain intensity (β = -1.8 [-4.9-1.2], P = .222) scores.

CONCLUSION

We found that medically supervised preoperative weight loss predicted improvement in physical function 3 months after TKA. This weight loss caused no major adverse effects. Further research is needed to understand the causal relationships between preoperative weight loss, medical supervision, and outcome after TKA and to elucidate potential longer-term benefits in a larger sample.

Risk Factors for Early Readmission and Reoperation After Outpatient Total Hip Arthroplasty

Outpatient total hip arthroplasty (THA) is a safe option for select patients. The purpose of this study was to analyze a national database and understand risk factors that lead to unplanned early readmission and reoperation after outpatient THA. The National Surgical Quality Improvement Program database was used to collect outpatient THAs performed from 2013 to 2020. The outpatient setting was defined as a reported hospital length of stay of 23 hours or less. Data variables collected included patient demographics, medical comorbidities, American Society of Anesthesiologists classification, functional status, preoperative laboratory values, National Surgical Quality Improvement Program morbidity probability, and 30-day readmissions and reoperations. A total of 15,055 patients underwent outpatient THA. Mean age was 62.6 years, and 52.1% of patients were men. Mean body mass index was 29.3 kg/m2. The overall rate of readmission was 1.8%, and the reoperation rate was 1.0%. Patients with a 30-day readmission were older (P<.01), with a higher incidence of hypertension (P<.01), steroid use (P<.01), and bleeding disorders (P=.01). Patients with a 30-day reoperation had higher body mass index (P<.01), hypertension (P<.01), and steroid use (P<.01). Regression analysis demonstrated that independent risk factors for readmission were age (P<.01) and steroid use (P<.01). Risk factors for 30-day reoperation were hypertension (P<.01) and steroid use (P<.01). There is a higher risk of early readmission after outpatient THA for older patients with hypertension, bleeding disorders, and steroid use. Patients with hypertension and steroid use have a higher risk for reoperation after outpatient THA. Modifiable risk factors should be addressed preoperatively, with proper patient selection for outpatient THA. [Orthopedics. 2024;47(1):e38-e44.].

Does Preoperative Weight Loss Within 6 Months or 1 Year Change the Risk of Adverse Outcomes in Total Knee Arthroplasty by Initial Body Mass Index Classification?

BACKGROUND

High body mass index (BMI) is associated with adverse outcomes after total knee arthroplasty (TKA). Thus, many patients are advised to lose weight before TKA. This study examined how weight loss before TKA is associated with adverse outcomes depending on patients' initial BMI.

METHODS

This was a retrospective study of 2,110 primary TKAs at a single academic center. Data on preoperative BMIs, demographics, comorbidities, and incidences of revision or prosthetic joint infection (PJI) were obtained. Multivariable logistic regressions segmented by patients' initial (1-year preoperative) BMI classifications were performed to determine if a > 5% BMI decrease from 1 year or 6 months preoperatively predicted PJI and revision controlling for patient age, race, sex, and Elixhauser comorbidity index.

RESULTS

Preoperative weight loss did not predict adverse outcomes for patients who had Obesity Class II or III. 6-month weight loss had greater odds of adverse outcomes than 1-year weight loss and most significantly predicted the occurrence of 1-year PJI (adjusted odds ratio: 6.55, P < .001) for patients who had Obesity Class 1 or lower.

CONCLUSION

This study does not show a statistically significant effect to patients who had Obesity Class II and III losing weight preoperatively with respect to PJI or revision. For patients who have Obesity Class I or lower pursuing TKA, future research should consider potential risks associated with weight loss. Further study is needed to determine if weight loss can be implemented as a safe and effective risk reduction strategy for specific BMI classes of TKA patients.

Higher Risk of Reoperation after Total Knee Arthroplasty in Young and Elderly Patients

As outcomes and survivorship improve, total knee arthroplasty (TKA) has expanded into broader age groups. The purpose of this study is to analyze the impact of age on TKA outcomes using the National Surgical Quality Improvement Program (NSQIP) database from 2015 to 2020. Patients were categorized into young (40-49 years), middle (50-79 years), and elderly (80-89 years) groups. Findings reveal notable differences across age groups. The young cohort had the highest BMI, smoking incidence, and steroid use, while the elderly group exhibited a higher prevalence of comorbidities. Young patients experienced shorter hospital stays (p < 0.001) but longer operative times (p < 0.001), and outpatient surgery was most common in the middle age group. Multivariable regression demonstrated that the elderly group faced increased risks of pneumonia (p < 0.001), acute renal failure (p < 0.001), stroke (p < 0.001), cardiac arrest (p < 0.001), and transfusions (p < 0.001), while both young and elderly patients had higher 30-day reoperation risks (youngest cohort, 1.4% and elderly cohort 1.3% (p < 0.001)). In summary, elderly patients undergoing TKA are at the highest risk for medical complications, while young patients are more likely to undergo inpatient surgery, experience reoperations, and have longer operative times. This study underscores the importance of age-specific counseling for TKA patients and contributes valuable insights into the evolving landscape of knee replacement surgery.

Preoperative Optimization for Orthopaedic Surgery: Steps to Reduce Complications

As the population ages and patients maintain higher levels of activity, the incidence of major and minor orthopaedic procedures continues to rise. At the same time, health policies are incentivizing efforts to improve the quality and value of musculoskeletal health services. As such, orthopaedic surgeons play a key role in directing the optimization of patients before surgery by assessing patient risk factors to inform risk/benefit discussions during shared decision-making and designing optimization programs to address modifiable risks. These efforts can lead to improved health outcomes, reduced costs, and preference-congruent treatment decisions. In this review, we (1) summarize the evidence on factors known to affect outcomes after common orthopaedic procedures, (2) identify which factors are considered modifiable and amenable to preoperative intervention, and (3) provide guidance for preoperative optimization.

Do You PROMIS (Patient Reported Outcomes Measurement Information System)? Physical Function and Pain Interference Scores After Total Knee and Hip Arthroplasty

Background

Physical function and pain outcomes vary after arthroplasty. We investigated differences in postoperative Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) and pain interference (PI) scores for patients undergoing total knee arthroplasty (TKA) and total hip arthroplasty (THA). We aimed to identify preoperative factors that predict postoperative PROMIS scores.

Methods

Patients who underwent TKA and THA from 2014-2020 were eligible. Preoperative variables including demographics, comorbidities, and pain scores were obtained from the medical record. Patients completed surveys measuring postoperative PF and PI. Descriptive statistics and separate linear regression models for each anatomical location were performed to examine factors predicting postoperative PROMIS PF and PI scores.

Results

Surveys were completed by 2411 patients (19.5% response rate). Unadjusted mean PF postoperative scores were 47.2 for TKA and 48.8 for THA. Preoperative predictors of lower PF included female sex; body mass index and comorbidities for TKA and THA; and age, tobacco use, and non-White race for THA. Mean PI scores were 47.9 for THA and 49.0 for TKA. Preoperative predictors of increased PI included non-White race and increased body mass index for TKA and THA; higher preoperative pain for TKA; and female sex and increased comorbidity for THA.

Conclusions

Postoperative PROMIS scores were similar for TKA and THA, with THA having slightly higher PF and lower PI scores. Regression models using preoperative variables showed similar performance for TKA compared with THA. These findings suggest areas for future development of clinical decision support tools.

Patients Who Have Kellgren-Lawrence Grade 3 and 4 Osteoarthritis Benefit Equally From Total Knee Arthroplasty

BACKGROUND

Recently, some payers have limited access to total knee arthroplasty (TKA) to patients who have Kellgren-Lawrence (KL) grade 4 osteoarthritis only. This study compared the outcomes of patients who have KL grade 3 and 4 osteoarthritis after TKA to determine if this new policy is justified.

METHODS

This was a secondary analysis of a series originally established to collect outcomes for a single, cemented implant design. A total of 152 patients underwent primary, unilateral TKA at two centers from 2014 to 2016. Only patients who had KL grade 3 (n = 69) or 4 (n = 83) osteoarthritis were included. There was no difference in age, sex, American Society of Anesthesiologists score, or preoperative Knee Society Score (KSS) between the groups. Patients who had KL grade 4 disease had a higher body mass index. KSS and Forgotten Joint Score (FJS) were collected preoperatively and at 6 weeks, 6 months, 1 year, and 2 years postoperatively. Generalized linear models were used to compare outcomes.

RESULTS

Controlling for demographics, improvements in KSS were comparable between the groups at all time points. There was no difference in KSS, FJS, and the proportion that achieved the patient acceptable symptom state for FJS at 2 years.

CONCLUSION

Patients who had KL grade 3 and 4 osteoarthritis experienced similar improvement at all time points up to 2 years after primary TKA. There is no justification for payers to deny access to surgical treatment for patients who have KL grade 3 osteoarthritis and have otherwise failed nonoperative treatment.

Evaluation of anterior translation in total knee arthroplasty utilizing stress radiographs

BACKGROUND

Flexion instability is a common cause for revision after total knee arthroplasty (TKA); however, little objective criteria exist to determine excessive laxity in flexion. This study sought to determine the reliability of stress radiographs for flexion laxity using manual stress as well as a commercially available flexion stress device, with the hypothesis that a commercially available force device would provide increased translation compared to manual stress, and radiographic measurements would be reproducible.

METHODS

Ten patients who previously underwent TKA with non-hinged components were prospectively and consecutively enrolled at a single center to undergo stress radiographs. Three lateral radiographs with the knee at 90° of flexion were obtained for each patient: rest, commercial stress device at 150N, and manual stress. Calibrated radiographs were evaluated by two raters, and inter-rater and intra-rater reliability were determined using intraclass correlation coefficients (ICC).

RESULTS

Ten patients (seven female) with mean age 72 (range 55-82) years and average duration from surgery 36 (range 12-96) months were evaluated. The commercial stress device provided significantly less anterior translation than manual stress (- 0.3 mm vs. 3.9 mm; p < 0.01). Two patients reported pain with use of the stress device. Inter-observer reliability of measurements was good for commercial stress (ICC = 0.86) and excellent for manual stress (ICC = 0.94). Eighty-five percent of measurements were within 1 mm between observers. Intra-observer reliability of measurements was good to excellent for both the stress device and manual stress.

CONCLUSIONS

Lateral stress radiographs may assist in the objective evaluation of flexion instability. A commercially available product provided less translation than manual stress; however, measurements were reliable and reproducible between observers. Further research is required to correlate translation with stress radiographs to patient outcomes following revision arthroplasty.

"Does order of operation matter in patients who have concomitant hip and spine pathology?"

INTRODUCTION

In patients who have coexisting lumbar spine and degenerative hip disease, there remains uncertainty regarding whether hip or spine surgery should be performed first. We hypothesized that undergoing total hip arthroplasty (THA) would protect against subsequent lumbar spine surgery (LSS) in patients who have 'hip-spine syndrome.'

METHODS

A retrospective cohort study was performed from 2013 to 2021 on patients who had radiographically-confirmed hip osteoarthritis and degenerative lumbar spine pathology, evaluated separately in spine and arthroplasty clinics prior to surgical intervention. Included patients ultimately underwent THA and/or LSS. The primary outcome was survivorship free of LSS or THA after the other was initially performed.

RESULTS

Of 256 patients, 206 (80.5%) underwent THA first. Only 14 of 206 (6.8%) who underwent THA required subsequent LSS, while 31 of 50 (62%) who underwent LSS required subsequent THA, (P<0.001). At 5 years, there was 93.9% survivorship-free of LSS in the THA first group, compared to 44.7% survivorship-free of subsequent THA in the LSS group. Multivariate analyses showed that patients who had THA first had lower odds of undergoing subsequent surgery (Odds Ratio (OR): 0.61, Confidence Interval (CI): 0.52-0.70, P<0.001) compared to those who underwent LSS first. Additionally, those who have higher initial Kellgren Lawrence (KL) grade hip osteoarthritis had lower odds (OR:0.94,CI:0.89-0.99, P=0.04), and those who have progressive neurologic deficits (OR:2.64, CI:1.89-3.7, P<0.001) and neurogenic claudication (OR:1.15, CI:1.06-1.24, P=0.001) had increased odds of undergoing subsequent LSS.

CONCLUSION

'Hip-spine syndrome' patients may receive more initial benefit from undergoing THA, potentially reducing the subsequent need for LSS. The exceptions were those patients who had lower-severity hip osteoarthritis and symptoms of major spinal stenosis.

Can PROMIS Measures Estimate High Impact Chronic Pain After Total Joint Arthroplasty?

BACKGROUND

High impact chronic pain (HICP) is not typically measured following orthopaedic surgeries, but has a substantial negative impact on post-operative quality of life. This analysis determined which Patient-Reported Outcome Measurement Information System (PROMIS) measures accurately estimate HICP status following total joint arthroplasty (TJA).

METHODS

This was a secondary analysis of a hip and knee TJA cohort. HICP status was determined by two items from the Graded Chronic Pain Scale-Revised. The cohort (n = 2,400) consisted of 47.5% hip (n = 1,142) and 52.5% knee TJA (n = 1,258). For total hip arthroplasty (THA), 53.7% were women (n = 615), 48.6% were 65 years or older (n = 557), 72.5% completed the survey more than 24 months after first surgery (n = 831), and 9.9% had HICP (n = 114). For total knee arthroplasty (TKA), 54.3% were women (n = 687), 59.3% were 65 years or older (n = 750), 72.3% survey completed the survey more than 24 months after first surgery (n = 915), and 11.5% had HICP (n = 145). Included PROMIS measures were pain interference, physical function, anxiety, and sleep disturbance. First, discriminant function analysis determined PROMIS measure contribution to HICP status. Then, area under the curve (AUC) calculated the accuracy of PROMIS measures to estimate HICP status. Influences of sociodemographic and surgical characteristics on AUC were explored in sensitivity analyses.

RESULTS

Results for TKA and THA were similar so they are presented collectively for the sake of brevity. Mean differences were identified for all PROMIS measures for those with HICP (All P values < 0.01). Pain interference (β = 0.934) and sleep disturbance (β = 0.154) were independently correlated with HICP status in discriminant function analyses. The AUC (95% Confidence Intervals) for HICP were as follows: pain interference (.952-.973), physical function (.921-.949), sleep (.780-.838), and anxiety (.687-.757). Sensitivity analyses revealed little change in AUC and HICP cut-off scores for PROMIS pain interference and physical function.

CONCLUSION

Two PROMIS measures commonly administered as standard of care for orthopaedics, pain interference and physical function, can be used to estimate HICP status for THA and TKA; thereby refining assessment of TJA outcomes.

The removal of total hip arthroplasty from the inpatient-only list has improved patient selection and expanded optimization efforts

INTRODUCTION

On January 1, 2020, the Centers for Medicare and Medicaid Services removed total hip arthroplasty (THA) from the Inpatient-Only (IPO) list. This study evaluated patient demographics and comorbidities, pre-operative optimization efforts, and 30-day outcomes of patients undergoing outpatient THA pre- and post- IPO-removal. The authors hypothesized that patients undergoing THA post-IPO removal would have improved optimization of modifiable risk factors and equivalent 30-day outcomes.

METHODS

There were 17,063 outpatient THA in a national database stratified by surgery performed pre- (2015 to 2019: 5,239 patients) and post-IPO (2020: 11,824 patients) removal. Demographics, comorbidities, and 30-day outcomes were compared with univariable and multivariable analyses. Pre-operative optimization thresholds were established for the following modifiable risk factors: albumin, creatinine, hematocrit, smoking history, and body mass index. The percentage of patients who fell outside the thresholds in each cohort were compared.

RESULTS

Patients undergoing outpatient THA post-IPO removal were significantly older; mean age 65 years (range, 18 to 92) vs 62 (range, 18 to 90) years (P<0.01), with a higher percentage of American Society of Anesthesiologists scores 3 and 4 (P<0.01). There was no difference in 30-day readmissions (P=0.57) or reoperations (P=1.00). A significantly lower percentage of patients fell outside the established threshold for albumin (P<0.01) post-IPO removal, and trended towards lower percentages for hematocrit and smoking status.

CONCLUSION

The removal of THA from the IPO list expanded patient selection for outpatient arthroplasty. Pre-operative optimization is critical to minimize post-operative complications, and the current study demonstrates that 30-day outcomes have not worsened post-IPO removal.

Accelerated Discharge After Aseptic Revision Total Hip Arthroplasty Does Not Predict Inferior 30-Day Outcomes

BACKGROUND

Perioperative advancements have made outpatient primary total hip arthroplasty (THA) a viable option for patients. This study evaluated the feasibility of expedited discharge after revision THA and compared 30-day outcomes to patients who had prolonged inpatient hospitalizations. The authors hypothesized that expedited discharge would not result in inferior 30-day outcomes.

METHODS

Aseptic revision THAs in a national database were reviewed from 2013 to 2020. THAs were stratified by hospital length of stay (LOS) more or less than 24 hours. Demographics, comorbidities, preoperative laboratory values, American Society of Anesthesiology (ASA) scores, operative times, components revised, 30-day readmissions, and reoperations were compared. Multivariable analyses evaluated predictors of discharge prior to 24 hours, 30-day readmissions, and reoperations. Of 17,044 aseptic revision THAs, 211 were discharged within 24 hours.

RESULTS

Accelerated discharge patients were younger, mean age 63 years (range, 20-92) versus 66 years (range, 18-94) (P < .01) had lower body mass index, mean 28.7 (range, 18.3-46.4) versus 29.9 (range, 17.3-52.5) (P = .01), and ASA scores (ASA, 1-2; 40.4-57.8%) (P < .01). Components revised had no association with LOS (P = .39); however, operative times were shorter and mean 100 minutes (range, 35-369) versus 139 minutes (range, 24-962) (P < .01) in accelerated discharge patients. Accelerated discharge patients had lower readmission rates (P < .01) but no difference in reoperation rates (P = .06).

CONCLUSION

Discharge less than 24 hours after revision THA is a feasible option for the correct patient and further efforts to decrease LOS should be evaluated.

Body Mass Index and American Society of Anesthesiologists Score Predict Perioperative Delays in Different Phases for Total Hip Arthroplasty

Perioperative efficiency has become increasingly important with cost constraints and expanding indications for total hip arthroplasty (THA). We chose to analyze body mass index (BMI) and American Society of Anesthesiologists (ASA) score, in predicting perioperative efficiency. We retrospectively reviewed the institutional database for primary THAs from July 2015 to January 2018. Patient demographics and perioperative times lines were collected. A multivariable model was utilized to evaluate BMI (< 30, ≥ 30) and ASA (< 3, ≥ 3) for all outcomes. A total of 2,934 patients were included with mean age 62.0 (12.2) years, and 1,599 (54.5%) were female. A BMI ≥ 30 was associated with prolonged operative time (p < 0.001) while an ASA ≥ 3 was predictive of post-anesthesia care unit time (p < 0.001), physical therapy hours (p < 0.001), and length of stay (p < 0.001). Both BMI (p = 0.004) and ASA (p < 0.001) were associated with skilled nursing/rehabilitation dispositions. While BMI predicts prolonged operative time, ASA predicts perioperative delays for anesthesia, nursing, and physical therapy. (Journal of Surgical Orthopaedic Advances 32(3):169-172, 2023).

Do Patients with Paget's Disease Have Worse Outcomes following Primary Total Knee Arthroplasty?

Well-powered studies evaluating the effects of Paget's disease on patient outcomes following primary total knee arthroplasty (TKA) are limited. The objective of this study was to determine whether Paget's disease patients undergoing primary TKA have higher rates of complications. A query of an administrative database was performed identifying Paget's disease patients undergoing primary TKA as the study cohort. Patients who did not have Paget's disease served as a matching cohort. Study group patients were matched in a 1:5 ratio by age, sex, and comorbidities. The query yielded 34,284 patients in the study (n = 5,714) and matched (n = 28,570) cohorts. Outcomes analyzed included length of stay (LOS), costs of care, 90-day medical and surgical complications, and 2-year implant-related complications. Multivariate logistic regression analyses were used to calculate the odds ratios (ORs) of complications. Paget's disease patients undergoing primary TKA were found to have significantly longer in-hospital LOS (4 vs. 3 days, p < 0.0001). Study group patients incurred significantly higher 90-day episode-of-care costs ($15,124.55 vs. $14,610.01, p < 0.0001). Additionally, Paget's disease patients were found to have higher incidences and odds of medical/surgical (25.93 vs. 13.58%; OR: 1.64, p < 0.0001) and implant-related complications (8.97 vs. 5.02%; OR: 1.71, p < 0.0001). Specifically, Paget's disease patients were more likely to have periprosthetic fractures, mechanical loosening, and revision TKAs (p < 0.0001). This study demonstrated that Paget's disease was associated with longer in-hospital LOS, increased costs, and higher rates of complications. The study can be utilized by physicians to adequately educate patients with Paget's disease concerning potential complications following their primary TKA.

A Validated Pre-operative Risk Prediction Tool for Extended Inpatient Length of Stay Following Primary Total Hip or Knee Arthroplasty

BACKGROUND

As value-based reimbursement models mature, understanding the potential trade-off between inpatient lengths of stay and complications or need for costly postacute care becomes more pressing. Understanding and predicting a patient's expected baseline length of stay may help providers understand how best to decide optimal discharge timing for high-risk total joint arthroplasty (TJA) patients.

METHODS

A retrospective review was conducted of 37,406 primary total hip (17,134, 46%) and knee (20,272, 54%) arthroplasties performed at two high-volume, geographically diverse, tertiary health systems during the study period. Patients were stratified by 3 binary outcomes for extended inpatient length of stay: 72 + hours (29%), 4 + days (11%), or 5 + days (5%). The predictive ability of over 50 sociodemographic/comorbidity variables was tested. Multivariable logistic regression models were created using institution #1 (derivation), with accuracy tested using the cohort from institution #2 (validation).

RESULTS

During the study period, patients underwent an extended length of stay with a decreasing frequency over time, with privately insured patients having a significantly shorter length of stay relative to those with Medicare (1.9 versus 2.3 days, P < .0001). Extended stay patients also had significantly higher 90-day readmission rates (P < .0001), even when excluding those discharged to postacute care (P < .01). Multivariable logistic regression models created from the training cohort demonstrated excellent accuracy (area under the curve (AUC): 0.755, 0.783, 0.810) and performed well under external validation (AUC: 0.719, 0.743, 0.763). Many important variables were common to all 3 models, including age, sex, American Society of Anesthesiologists (ASA) score, body mass index, marital status, bilateral case, insurance type, and 13 comorbidities.

DISCUSSION

An online, freely available, preoperative clinical decision tool accurately predicts risk of extended inpatient length of stay after TJA. Many risk factors are potentially modifiable, and these validated tools may help guide clinicians in preoperative patient counseling, medical optimization, and understanding optimal discharge timing.

Accelerated discharge after aseptic revision knee arthroplasty is not associated with early readmission and reoperation

Aims

In the last decade, perioperative advancements have expanded the use of outpatient primary total knee arthroplasty (TKA). Despite this, there remains limited data on expedited discharge after revision TKA. This study compared 30-day readmissions and reoperations in patients undergoing revision TKA with a hospital stay greater or less than 24 hours. The authors hypothesized that expedited discharge in select patients would not be associated with increased 30-day readmissions and reoperations.

Methods

Aseptic revision TKAs in the National Surgical Quality Improvement Program database were reviewed from 2013 to 2020. TKAs were stratified by length of hospital stay (greater or less than 24 hours). Patient demographic details, medical comorbidities, American Society of Anesthesiologists (ASA) grade, operating time, components revised, 30-day readmissions, and reoperations were compared. Multivariate analysis evaluated predictors of discharge prior to 24 hours, 30-day readmission, and reoperation.

Results

Of 21,610 aseptic revision TKAs evaluated, 530 were discharged within 24 hours. Short-stay patients were younger (63.1 years (49 to 78) vs 65.1 years (18 to 94)), with lower BMI (32.3 kg/m2 (17 to 47) vs 33.6 kg/m2 (19 to 54) and lower ASA grades. Diabetes, chronic obstructive pulmonary disease, hypertension, and cancer were all associated with a hospital stay over 24 hours. Single component revisions (56.8% (n = 301) vs 32.4% (n = 6,823)), and shorter mean operating time (89.7 minutes (25 to 275) vs 130.2 minutes (30 to 517)) were associated with accelerated discharge. Accelerated discharge was not associated with 30-day readmission and reoperation.

Conclusion

Accelerated discharge after revision TKA did not increase short-term complications, readmissions, or reoperations. Further efforts to decrease hospital stays in this setting should be evaluated. Cite this article: Bone Joint J 2022;104-B(12):1323–1328.

Commercial Claims Data Sources: PearlDiver and Individual Payer Databases

Individual or pooled commercial claims data sources such as the IBM MarketScan and PearlDiver provide information from health-care encounters by individuals enrolled in participating health insurance plans. These data sources contain deidentified data on demographic characteristics, enrollment start and end dates, inpatient and outpatient procedures and medical diagnoses with associated service dates and settings, and dispensed medications. Although there are concerns that long-term follow-up is limited because of interruptions in the continuity of coverage and reliance on billing data may overrecord or underrecord diagnoses and confounders, these data sources are nevertheless valuable for orthopaedic studies focusing on short-term complications, costs, and utilization.

Sleep disturbance, dyspnea, and anxiety following total joint arthroplasty: an observational study

Background

Patient-Reported Outcomes Measurement Information System (PROMIS) domains for sleep disturbance, anxiety, and dyspnea have been under-reported for total joint arthroplasty (TJA). The aims of this study were to report postoperative differences for these domains based on TJA location and chronic pain state. We also investigated whether these domains were associated with physical function and pain interference outcomes.

Methods

This was a retrospective, observational study of patients who underwent hip, knee, or shoulder TJA (primary and revision surgeries) at a single academic tertiary referral center. A subset of these patients completed an email-based survey for chronic pain grade (Chronic Pain Grade Scale-Revised) and sleep disturbance, anxiety, dyspnea, physical function, and pain interference (PROMIS short forms). Pre-operative and operative data were extracted from the electronic health record. Data analysis investigated PROMIS domains for differences in TJA location and chronic pain grade. Hierarchical linear regression determined associations of these domains with physical function and pain interference.

Results

A total of 2638 individuals provided informed consent and completed the email survey. In the ANOVA models for sleep disturbance, anxiety, and dyspnea, there was no location by chronic pain grade interaction (p > 0.05) and no difference based on TJA location (p > 0.05). There were differences for chronic pain grade (p < 0.01). The poorest postoperative outcome score for each domain was associated with high impact chronic pain. Furthermore, sleep disturbance and dyspnea had the strongest associations with physical function and pain interference (p < 0.01).

Conclusions

Sleep disturbance, anxiety, and dyspnea did not vary based on TJA location, but were associated with postoperative chronic pain grade. Sleep disturbance and dyspnea were strongly associated with commonly reported outcomes of physical function and pain interference. These findings provide guidance for those interested in expanding TJA outcome assessment to include sleep disturbance, anxiety, and/or dyspnea.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03288-x.

Racial and Ethnic Disparities in the Imaging Workup and Treatment of Knee and Hip Osteoarthritis

BACKGROUND

There is limited evidence on sociodemographic differences in osteoarthritis management, particularly in non-African American (AA) minorities. We sought to identify differences in imaging modalities, administration of intra-articular injections, and total joint arthroplasty (TJA) between racial/ethnic groups.

METHODS

We retrospectively reviewed patients presenting to outpatient clinics with a diagnosis of hip or knee osteoarthritis from January 2013 to March 2020 at a tertiary center. Univariate analyses compared differences between groups. Multivariate logistic regression analyses determined sociodemographic predictors of imaging workup and treatment.

RESULTS

In total, 105,873 patients were included. There were 74,769 (70.6%) Caucasian, 27,117 (25.6%) AA, 1,878 (1.8%) Hispanic, 1,479 (1.4%) Asian, and 630 (0.6%) Native American patients. Multivariate analyses demonstrated that AAs had decreased odds of undergoing a knee magnetic resonance imaging (odds ratio [OR] 0.77, P < .001) or injection (OR 0.94, P = .006). Asian patients had lower odds of receiving any hip X-ray (OR 0.72, P = .047) or knee injection (OR 0.83, P = .017). AA (total knee arthroplasty [TKA]: OR 0.51, P < .001; total hip arthroplasty [THA]: OR 0.57, P < .001), Hispanic (TKA: OR 0.69, P = .003; THA: OR 0.60, P = .006), and Asian (TKA: OR 0.73, P = .010; THA: OR 0.56, P = .010) patients had lower odds of undergoing TJA compared to Caucasians. We found that higher income quartiles had greater odds of receiving a magnetic resonance imaging and TJA, males had lower odds of receiving injections and greater odds of undergoing TJA, and Medicaid and self-pay patients had lower odds of undergoing TJA (P < .05).

CONCLUSION

After adjusting for sociodemographic factors, we found disparities in the imaging, administration of injections, and/or arthroplasty for AA, Asian, and Hispanic patients. Insurance status, income, and gender were also associated with imaging and treatments performed in managing hip and knee osteoarthritis.

Risk Factors for Delayed Discharge and Adverse Outcomes Following Outpatient Billed Total Knee Arthroplasty

BACKGROUND

The volume of outpatient total knee arthroplasty (TKA) has increased with advances in perioperative protocols, patient selection, and recent policy changes regarding insurance authorization. This study analyzed 30-day outcomes from a national database to better understand risk factors for delayed discharge (length of stay [LOS] ≥1), readmission, and reoperation after outpatient TKA.

METHODS

The National Surgical Quality Improvement Program (NSQIP) database was utilized to collect TKA (CPT 27447) billed as outpatient surgery performed from 2013 to 2018. Patient demographics, comorbidities, and short-term outcomes were collected and compared in LOS 0 versus LOS ≥1 cohorts. Subgroup analysis was completed for TKA performed in 2018, after the Center for Medicare Services removal of TKA from the inpatient-only list.

RESULTS

A total of 13,669 patients had outpatient TKA performed from 2013 to 2018. Most patients had LOS ≥1 day (77.1%). The LOS 0 cohort demonstrated a lower 30-day readmission rate (1.8%) compared to LOS ≥1 (2.8%), P > .01. Both groups demonstrated a low 30-day reoperation rate, LOS 0 (0.7%) and LOS ≥1 (1.1%), P = .05. Regression analysis demonstrated risk factors for LOS ≥1 day included COPD, ASA ≥3, age >75, and BMI >35 kg/m². Regression analysis demonstrated male gender, age >75, ASA ≥3, and albumin <3.5 g/dL were risk factors for readmission. Hypertension was a risk factor for 30-day reoperation.

CONCLUSION

Risk factors for LOS ≥1 day include age >75, ASA ≥3, BMI >35 kg/m². In addition, BMI >35 kg/m² was a risk factor for readmission and reoperation. These findings reinforce appropriate patient selection when considering outpatient TKA.

Chronic Pain Prevalence and Factors Associated With High Impact Chronic Pain following Total Joint Arthroplasty: An Observational Study

Hip, knee, and shoulder arthroplasty are among the most frequently performed orthopaedic procedures in the United States. High impact and bothersome chronic pain rates following total joint arthroplasty (TJA) are unknown; as are factors that predict these chronic pain outcomes. This retrospective observational study included individuals that had a TJA from January 2014 to January 2020 (n = 2,638). Pre-operative and clinical encounter information was extracted from the electronic health record and chronic pain state was determined by email survey. Predictor variables included TJA location, number of surgeries, comorbidities, tobacco use, BMI, and pre-operative pain intensity. Primary outcomes were high impact and bothersome chronic pain. Rates of high impact pain (95% CI) were comparable for knee (9.8-13.3%), hip (8.3-11.8%) and shoulder (7.6-16.3%). Increased risk of high impact pain included non-white race, two or more comorbidities, age less than 65 years, pre-operative pain scores 5/10 or higher, knee arthroplasty, and post-operative survey completion 24 months or less. Rates of bothersome chronic pain (95% CI) were also comparable for knee (24.9-29.9%) and hip (21.3-26.3%) arthroplasty; but higher for shoulder (26.9-39.6%). Increased risk of bothersome chronic pain included non-white race, shoulder arthroplasty, knee arthroplasty, current or past tobacco use, and being female. PERSPECTIVE: In this cohort more than 1/3rd of individuals reported high impact or bothersome chronic pain following TJA. Non-white race and knee arthroplasty were the only two variables associated with both chronic pain outcomes.

Total Knee Arthroplasty in Patients with Dementia

There are few studies evaluating total knee arthroplasty (TKA) in patients with dementia. The purpose of this study was to evaluate the rate of revision, complication, emergency department (ED) visitation, and discharge disposition in patients with dementia undergoing primary TKA. In this retrospective study, we evaluated patients from 2007 to 2017 using a national database. Ninety-day complications in patients with dementia undergoing TKA were increased risk of ED visitation and skilled nursing facility (SNF) disposition (p  ≤  0.05). Two-year complications in patients with dementia undergoing TKA were increased risk of ED visitation and SNF disposition (p  ≤  0.05). Patients with dementia undergoing TKA are at an increased risk of resource utilization.

Revision Total Joint Arthroplasty: Final Stop Tertiary Referral Center

High complication rates associated with revision total knee arthroplasty (TKA) and total hip arthroplasty (THA) may unequally burden tertiary referral centers, which manage medically complex patients. The authors aimed to quantify TKA and THA referral patterns at a tertiary referral center based on travel distance and patient comorbidities. All patients who underwent primary or revision TKA or THA at the investigating institution from 2012 to 2016 were identified. Travel distance was calculated using each patient's home address and stratified into less than 25 miles, 25 to 74 miles, and 75 miles or more. Age, body mass index, Charlson Comorbidity Index, and postoperative clinical data were identified. Patients were analyzed based on procedure performed and travel distance. A total of 4245 procedures were included for analysis (1754 primary TKAs, 432 revision TKAs, 1503 primary THAs, and 556 revision THAs). Patients living 75 miles or more away had significantly higher odds of undergoing revision arthroplasty compared with patients living within 25 miles (knee: odds ratio [OR], 2.43; hip: OR, 2.61; P<.001). Charlson Comorbidity Index did not increase with travel distance. Patients traveling 75 miles or more were more likely to have periprosthetic fracture (OR, 3.91; P=.011) and less likely to have dislocation (OR, 0.54; P=.026) as the surgical indication for revision. Patients referred to a tertiary center were more likely to necessitate revision total joint arthroplasty but did not differ in comorbidity profile compared with local patients. Periprosthetic fracture, a particularly high-risk surgical indication, was overrepresented among referral patients. These data suggest that factors such as underlying diagnosis, but not preoperative medical comorbidities, may influence referral patterns. [Orthopedics. 2021;44(4):e477-e481.].

Flash Sterilization and Component Reimplantation Is a Viable Option for Articulating Antibiotic Spacers in Periprosthetic Knee Infections

The articulating antibiotic spacer is a treatment utilized for two-stage revision of an infected total knee arthroplasty. The original femoral component is retained and reused in one described variation of this technique. The purpose of this study is to determine the safety and efficacy of flash sterilization of the femoral component for reimplantation in an articulating antibiotic spacer for the treatment of chronic periprosthetic joint infection. A total of 10 patients were identified prospectively with a culture positive infected total knee arthroplasty. The patients underwent explantation, debridement, and placement of an articulating antibiotic spacer consisting of the explanted and sterilized femoral component and a new polyethylene tibial insert. The explanted tibial components were cleaned and flash-sterilized with the femoral components, but the components were then aseptically packaged and sent to our microbiology laboratory for sonication and culture of the sonicate for 14 days. Ten of 10 cleaned tibial components were negative for bacterial growth of the infecting organism after final testing and analysis. At 18-month follow-up, 9 of 10 of patients remained clear of infection. Among the 10 patients, 7 were pleased with their articulating spacer construct and had no intention of electively pursuing reimplantation. Also, 3 of 10 of patients were successfully reimplanted at a mean of 6.5 months after explantation. Autoclave sterilization and reimplantation of components may be a safe and potentially resource-sparing method of articulating spacer placement in two-stage treatment of PJI. Patient follow-up demonstrated clinical eradication of infection in 90% of cases with good patient tolerance of the antibiotic spacer.

Angiotensin Receptor Blockers Were Not Associated With Decreased Arthrofibrosis After Total Knee Arthroplasty

Stiffness after total knee arthroplasty (TKA) remains a challenging problem. Angiotensin receptor blockers (ARBs) have been associated with decreased muscle fibrosis. The aim of this study was to evaluate whether perioperative use of ARBs was associated with a reduction in arthrofibrosis and manipulation under anesthesia (MUA) in patients undergoing primary TKA at 90 days and 1 year postoperative. In this retrospective study, the authors used a national database to evaluate patients undergoing TKA for primary osteoarthritis from 2007 to 2017. They evaluated patients with filled prescriptions for ARBs within the study time frame and the specific type of ARB and its association with arthrofibrosis and MUA. After adjusting for age, sex, a comorbidity index, and obesity, any ARB or specific ARBs were not associated with a reduction in the rate of arthrofibrosis or MUA after TKA (P≥.05). Male sex, age 55 years or older, and obesity were associated with a reduction in the rate of arthrofibrosis and MUA after TKA (P≤.05). Studies should be performed to evaluate ARBs to see whether there is a more specific role in preventing joint stiffness in certain patient subpopulations following TKA. [Orthopedics. 2021;44(2):e274-e280.].

Can PROMIS measures be used to create subgroups for patients seeking orthopaedic care?

Aims

Patient-reported outcome measures have become an important part of routine care. The aim of this study was to determine if Patient-Reported Outcomes Measurement Information System (PROMIS) measures can be used to create patient subgroups for individuals seeking orthopaedic care.

Methods

This was a cross-sectional study of patients from Duke University Department of Orthopaedic Surgery clinics (14 ambulatory and four hospital-based). There were two separate cohorts recruited by convenience sampling (i.e. patients were included in the analysis only if they completed PROMIS measures during a new patient visit). Cohort #1 (n = 12,141; December 2017 to December 2018,) included PROMIS short forms for eight domains (Physical Function, Pain Interference, Pain Intensity, Depression, Anxiety, Sleep Quality, Participation in Social Roles, and Fatigue) and Cohort #2 (n = 4,638; January 2019 to August 2019) included PROMIS Computer Adaptive Testing instruments for four domains (Physical Function, Pain Interference, Depression, and Sleep Quality). Cluster analysis (K-means method) empirically derived subgroups and subgroup differences in clinical and sociodemographic factors were identified with one-way analysis of variance.

Results

Cluster analysis yielded four subgroups with similar clinical characteristics in Cohort #1 and #2. The subgroups were: 1) Normal Function: within normal limits in Physical Function, Pain Interference, Depression, and Sleep Quality; 2) Mild Impairment: mild deficits in Physical Function, Pain Interference, and Sleep Quality but with Depression within normal limits; 3) Impaired Function, Not Distressed: moderate deficits in Physical Function and Pain Interference, but within normal limits for Depression and Sleep Quality; and 4) Impaired Function, Distressed: moderate (Physical Function, Pain Interference, and Sleep Quality) and mild (Depression) deficits.

Conclusion

These findings suggest orthopaedic patient subgroups differing in physical function, pain, and psychosocial distress can be created from as few as four different PROMIS measures. Longitudinal research is necessary to determine whether these subgroups have prognostic validity.

Cite this article: Bone Jt Open 2021;2(7):493–502.

Mid-term results of tibial cones : reasonable survivorship but increased failure in those with significant bone loss and prior infection

AIMS

Tibial cones are often utilized in revision total knee arthroplasty (TKA) with metaphyseal defects. Because there are few studies evaluating mid-term outcomes with a sufficient cohort, the purpose of this study was to evaluate tibial cone survival and complications in revision TKAs with tibial cones at minimum follow-up of five years.

METHODS

A retrospective review was completed from September 2006 to March 2015, evaluating 67 revision TKAs (64 patients) that received one specific porous tibial cone during revision TKA. The final cohort was composed of 62 knees (59 patients) with five years of clinical follow-up or reoperation. The mean clinical follow-up of the TKAs with minimum five-year clinical follow-up was 7.6 years (5.0 to 13.3). Survivorship analysis was performed with the endpoints of tibial cone revision for aseptic loosening, tibial cone revision for any reason, and reoperation. We also evaluated periprosthetic joint infection (PJI), risk factors for failure, and performed a radiological review.

RESULTS

The rate of cone revision for aseptic loosening was 6.5%, with an eight-year survival of 95%. Significant bone loss (Anderson Orthopaedic Research Institute grade 3) was associated with cone revision for aseptic loosening (p = 0.002). The rate of cone revision for any reason was 17.7%, with an eight-year survival of 84%. Sixteen percent of knees developed PJI following revision. A pre-revision diagnosis of reimplantation as part of a two-stage exchange protocol for infection was associated with both PJI (p < 0.001) and tibial cone revision (p = 0.001).

CONCLUSION

Mid-term results of tibial cones showed a survivorship free of cone revision for aseptic loosening of 95%. Patients with significant bone loss were more likely to have re-revision for tibial cone failure. Infection was common, and patients receiving cones at reimplantation were more likely to develop PJI and undergo cone revision. Cite this article: Bone Joint J 2021;103-B(6 Supple A):158-164.

The MARBLE Study Protocol: Modulating ApoE Signaling to Reduce Brain Inflammation, DeLirium, and PostopErative Cognitive Dysfunction

BACKGROUND

Perioperative neurocognitive disorders (PND) are common complications in older adults associated with increased 1-year mortality and long-term cognitive decline. One risk factor for worsened long-term postoperative cognitive trajectory is the Alzheimer's disease (AD) genetic risk factor APOE4. APOE4 is thought to elevate AD risk partly by increasing neuroinflammation, which is also a theorized mechanism for PND. Yet, it is unclear whether modulating apoE4 protein signaling in older surgical patients would reduce PND risk or severity.

OBJECTIVE

MARBLE is a randomized, blinded, placebo-controlled phase II sequential dose escalation trial designed to evaluate perioperative administration of an apoE mimetic peptide drug, CN-105, in older adults (age≥60 years). The primary aim is evaluating the safety of CN-105 administration, as measured by adverse event rates in CN-105 versus placebo-treated patients. Secondary aims include assessing perioperative CN-105 administration feasibility and its efficacy for reducing postoperative neuroinflammation and PND severity.

METHODS

201 patients undergoing non-cardiac, non-neurological surgery will be randomized to control or CN-105 treatment groups and receive placebo or drug before and every six hours after surgery, for up to three days after surgery. Chart reviews, pre- and postoperative cognitive testing, delirium screening, and blood and CSF analyses will be performed to examine effects of CN-105 on perioperative adverse event rates, cognition, and neuroinflammation. Trial results will be disseminated by presentations at conferences and peer-reviewed publications.

CONCLUSION

MARBLE is a transdisciplinary study designed to measure CN-105 safety and efficacy for preventing PND in older adults and to provide insight into the pathogenesis of these geriatric syndromes.

Body Mass Index, American Society of Anesthesiologists Score, and Elixhauser Comorbidity Index Predict Cost and Delay of Care During Total Knee Arthroplasty

BACKGROUND

Body mass index (BMI), American Society of Anesthesiologists (ASA) score, and Elixhauser Comorbidity Index are measures that are utilized to predict perioperative outcomes, though little is known about their comparative predictive effects. We analyzed the effects of these indices on costs, operating room (OR) time, and length of stay (LOS) with the hypothesis that they would have a differential influence on each outcome variable.

METHODS

A retrospective review of the institutional database was completed on primary TKA patients from 2015 to 2018. Univariable and multivariable models were constructed to evaluate the strength of BMI, ASA, and Elixhauser comorbidities for predicting changes to total hospital and surgical costs, OR time, and LOS.

RESULTS

In total, 1313 patients were included. ASA score was independently predictive of all outcome variables (OR time, LOS, total hospital and surgical costs). BMI, however, was associated with intraoperative resource utilization through time and cost, but only remained predictive of OR time in an adjusted model. Total Elixhauser comorbidities were independently predictive of LOS and total hospital cost incurred outside of the operative theater, though they were not predictive of intraoperative resource consumption.

CONCLUSION

Although ASA, BMI, and Elixhauser comorbidities have the potential to impact outcomes and cost, there are important differences in their predictive nature. Although BMI is independently predictive of intraoperative resource utilization, other measures like Elixhauser and ASA score were more indicative of cost outside of the OR and LOS. These data highlight the differing impact of BMI, ASA, and patient comorbidities in impacting cost and time consumption throughout perioperative care.

A Preoperative Risk Prediction Tool for Discharge to a Skilled Nursing or Rehabilitation Facility After Total Joint Arthroplasty

BACKGROUND

Discharge to rehabilitation or a skilled nursing facility (SNF) after total joint arthroplasty remains a primary driver of cost excess for bundled payments. An accurate preoperative risk prediction tool would help providers and health systems identify and modulate perioperative care for higher risk individuals and serve as a vital tool in preoperative clinic as part of shared decision-making regarding the risks/benefits of surgery.

METHODS

A total of 10,155 primary total knee (5,570, 55%) and hip (4,585, 45%) arthroplasties performed between June 2013 and January 2018 at a single institution were reviewed. The predictive ability of 45 variables for discharge location (SNF/rehab vs home) was tested, including preoperative sociodemographic factors, intraoperative metrics, postoperative labs, as well as 30 Elixhauser comorbidities. Parameters surviving selection were included in a multivariable logistic regression model, which was calibrated using 20,000 bootstrapped samples.

RESULTS

A total of 1786 (17.6%) cases were discharged to a SNF/rehab, and a multivariable logistic regression model demonstrated excellent predictive accuracy (area under the receiver operator characteristic curve: 0.824) despite requiring only 9 preoperative variables: age, partner status, the American Society of Anesthesiologists score, body mass index, gender, neurologic disease, electrolyte disorder, paralysis, and pulmonary circulation disorder. Notably, this model was independent of surgery (knee vs hip). Internal validation showed no loss of accuracy (area under the receiver operator characteristic curve: 0.8216, mean squared error: 0.0004) after bias correction for overfitting, and the model was incorporated into a readily available, online prediction tool for easy clinical use.

CONCLUSION

This convenient, interactive tool for estimating likelihood of discharge to a SNF/rehab achieves excellent accuracy using exclusively preoperative factors. These should form the basis for improved reimbursement legislation adjusting for patient risk, ensuring no disparities in access arise for vulnerable populations.

LEVEL OF EVIDENCE

III.

Same-day Bilateral Total Knee Arthroplasty Did Not Increase 90-day Hospital Returns

PURPOSE

Bilateral total knee arthroplasty (TKA) can be performed in patients with bilateral knee arthritis. Outside of nationwide database studies, which have limitations, few studies have compared outcomes for same-day versus staged TKA. We sought to compare patient outcomes at a single tertiary referral center.

METHODS

The institutional database was queried from March 2014 to December 2017 for primary TKA. Patients undergoing bilateral procedures were stratified by same-day versus staged; length of stay (LOS), disposition, 90-day emergency department (ED) visits, and 90-day readmissions were examined through univariable and multivariable analyses.

RESULTS

A total of 676 patients were evaluated (113 same-day and 563 staged bilateral TKA patients) with mean age 66.0 (8.5) at first surgery and 292.1 (241.6) days between staged procedures. Same-day bilateral TKA patients were younger (p < 0.001), had lower body mass index (BMI) (p = 0.010), and had lower American Society of Anesthesiologists (ASA) scores (p = 0.030). They were more likely to have a prolonged LOS (p < 0.001) and be discharged to skilled nursing facility or rehab facility (p < 0.001). Total LOS for separate hospitalizations in staged procedures was greater than LOS for same-day bilateral TKAs (p < 0.001). There was no difference in 90-day ED visits (p = 0.623) or readmission (p = 0.286). In a multivariable model controlling for age, BMI, and ASA score, same-day bilateral TKA was not significantly associated with ED visits or readmissions.

CONCLUSIONS

Patients undergoing same-day bilateral TKAs were more likely to be discharged to post-acute care facilities, however they did not have increased 90-day readmissions.

Next-generation sequencing not superior to culture in periprosthetic joint infection diagnosis

AIMS

Use of molecular sequencing methods in periprosthetic joint infection (PJI) diagnosis and organism identification have gained popularity. Next-generation sequencing (NGS) is a potentially powerful tool that is now commercially available. The purpose of this study was to compare the diagnostic accuracy of NGS, polymerase chain reaction (PCR), conventional culture, the Musculoskeletal Infection Society (MSIS) criteria, and the recently proposed criteria by Parvizi et al in the diagnosis of PJI.

METHODS

In this retrospective study, aspirates or tissue samples were collected in 30 revision and 86 primary arthroplasties for routine diagnostic investigation for PJI and sent to the laboratory for NGS and PCR. Concordance along with statistical differences between diagnostic studies were calculated.

RESULTS

Using the MSIS criteria to diagnose PJI as the reference standard, the sensitivity and specificity of NGS were 60.9% and 89.9%, respectively, while culture resulted in sensitivity of 76.9% and specificity of 95.3%. PCR had a low sensitivity of 18.4%. There was no significant difference based on sample collection method (tissue swab or synovial fluid) (p = 0.760). There were 11 samples that were culture-positive and NGS-negative, of which eight met MSIS criteria for diagnosing infection.

CONCLUSION

In our series, NGS did not provide superior sensitivity or specificity results compared to culture. PCR has little utility as a standalone test for PJI diagnosis with a sensitivity of only 18.4%. Currently, several laboratory tests for PJI diagnosis should be obtained along with the overall clinical picture to help guide decision-making for PJI treatment. Cite this article: Bone Joint J 2021;103-B(1):26-31.

A Case Complexity Modifier Is Warranted for Primary Total Knee Arthroplasty

BACKGROUND

The Center for Medicare and Medicaid Services is faced with a challenge of decreasing the cost of care for total knee arthroplasty (TKA) but must make efforts to prevent patient selection bias in the process. Currently, no appropriate modifier codes exist for primary TKA based on case complexity. We sought to determine differences in perioperative parameters for patients with complex primary TKA with the hypothesis that they would require increased cost of care, prolonged care times, and have worse postoperative outcome metrics.

METHODS

We performed a single-center retrospective review from 2015 to 2018 of all primary TKAs. Patient demographics, medial proximal tibial angle (mPTA), lateral distal femoral angle (lDFA), flexion contracture, cost of care, and early postoperative outcomes were collected. Complex patients were defined as those requiring stems or augments, and multivariable logistic regression analysis and propensity score matching were performed to evaluate perioperative outcomes.

RESULTS

About 1043 primary TKAs were studied, and 84 patients (8.3%) were deemed complex. For this cohort, surgery duration was greater (P < .001), cost of care higher (P < .001), and patients had a greater likelihood for 90-day hospital return. Deviation of mPTA and lDFA was significantly greater preoperatively before and after propensity score matching. Cut point analysis demonstrated that preoperative mPTA <83^o or >91^o, lDFA <84^o or >90^o, flexion contracture >10^o, and body mass index >35.7 were associated with complex procedures.

CONCLUSION

Complex primary TKA may be identifiable preoperatively and those cases associated with prolonged operative time, excess hospital cost of care, and increased 90-day hospital returns. This should be considered in future reimbursement models to prevent patient selection bias, and a complexity modifier is warranted.

All-Polyethylene Tibia: An Opportunity for Value-Based Care in Bundled Reimbursement Initiatives

Surgeons play a critical role in making cost-effective decisions that maintain high-quality patient outcomes, which is the current focus of the Centers for Medicare & Medicaid Services. All-polyethylene tibial (APT) components often cost less during total knee arthroplasty (TKA). The authors sought to determine the relative cost savings of APT, as well as their effect on 90-day quality outcome metrics. This was a retrospective review of primary TKAs performed at a single tertiary referral center participating in the Comprehensive Care for Joint Replacement model, by 2 surgeons, from 2015 to 2017. Patient demographic data and direct hospital costs were collected, and patients were stratified by APTs vs metal-backed components. Univariable and multivariable analyses were performed for all outcome metrics. A total of 188 primary TKAs were included (92 APT, 96 metal-backed). Patients receiving APT components were older (P<.001) and had a lower body mass index (P<.001), but there was no difference in sex or American Society of Anesthesiologists score between groups. Operative time was significantly less (mean, 13 minutes) and direct surgery costs were significantly lower for APTs (P<.001). A multivariable regression model for surgical costs demonstrated significant savings (P<.001), and total hospital cost demonstrated a 6.2% average savings with APT. There was no difference in 90-day emergency department visits or re-admissions. This study demonstrates that the use of an APT is able to significantly affect not only the surgical cost but also the total hospital admission cost while maintaining equivalent 90-day outcome metrics. Strategies like this should be considered in appropriately selected patients as the incidence of TKA continues to expand. [Orthopedics. 2021;44(1):e114-e118.].

The Calpain Gene is Correlated With Metal-on-Metal Hip Replacement Failures

BACKGROUND

Metal-on-metal (MOM) total hip arthroplasty is associated with unacceptable failure rates secondary to metal ion reactions. Efforts to identify which patients will go on to failure have been limited; recently, there has been a suggestion for a potential genetic basis for the increased risk of revision in MOM hip replacements (MOMHRs). The purpose of this study is to determine whether certain immunologic genotypes are predictive of the need for revision in patients with MOM total hip implants.

METHODS

This is a case-control study of all patients undergoing primary MOMHR between September 2002 and January 2012 with a minimum of 5-year follow-up. Our investigational "case" cohort was comprised of patients who underwent revision for MOMHR for a reason other than infection. A single-nucleotide polymorphism (SNP) array analysis was performed to identify a potential genetic basis for failure.

RESULTS

Thirty-two patients (15 case and 17 control) were included in our analysis. All patients in the revision group had a chief complain of pain; revision patients were more likely to have a posterior approach (P = .01) and larger head size (P = .04) than nonrevision patients. No patient or implant characteristics were independently associated with revision in a multivariate analysis. Patients with SNP kgp9316441 were identified as having an increased odds of revision for MOM failure (P < .001).

CONCLUSION

This study identified an SNP, kgp9316441, encoding proteins associated with inflammation and macrophage activation. This SNP was associated with significantly increased odds of revision for MOMHR. Future studies are warranted to validate this gene target both in vitro and in vivo.

LEVEL OF EVIDENCE

III.

Patient Preferences for Surgical Treatment of Knee Osteoarthritis: A Discrete-Choice Experiment Evaluating Total and Unicompartmental Knee Arthroplasty

BACKGROUND

Total knee arthroplasty (TKA) is a common treatment for end-stage knee osteoarthritis but is associated with increased complication rates compared with unicompartmental knee arthroplasty (UKA). UKA offers better functional outcomes but is associated with a higher risk of revision. The purpose of this study was to apply good-practice, stated-preference methods to quantify patient preferences for benefit-risk tradeoffs associated with arthroplasty treatments for end-stage knee osteoarthritis.

METHODS

A discrete-choice experiment was developed with the following attributes: chance of complications, functional ability, awareness of the knee implant, and chance of needing another operation within 10 years. Patients included those aged 40 to 80 years with knee osteoarthritis. A pivot design filtered respondents into 1 of 2 surveys on the basis of self-reported functional ability (good compared with fair or poor) as measured by the Oxford Knee Score. Treatment-preference data were collected, and relative attribute-importance weights were estimated.

RESULTS

Two hundred and fifty-eight completed survey instruments from 92 males and 164 females were analyzed, with 72 respondents in the good-function cohort and 186 in the fair/poor-function cohort. Patients placed the greatest value or relative importance on serious complications and rates of revision in both cohorts. Preference weights did not vary between cohorts for any attribute. In the good-function cohort, 42% of respondents chose TKA and 58% chose UKA. In the fair/poor-function cohort, 54% chose TKA and 46% chose UKA.

CONCLUSIONS

Patient preferences for various treatment attributes varied among patients in a knee osteoarthritis population. Complication and revision rates were the most important factors to patients, suggesting that physicians should focus on these areas when discussing treatments. The proportion of patients who chose UKA suggests that the current trend of increased UKA utilization is aligned with patient preferences.

CLINICAL RELEVANCE

Systematic elicitation of patient preferences for knee arthroplasty procedures, which lays out evidence-based risks and benefits of different treatments, indicates a larger subset of the knee osteoarthritis population may prefer UKA than would be suggested by the current rates of utilization of the procedure. Arthroplasty treatment should align with patient preferences and eligibility criteria to better deliver patient-centered care.

A Specific Capsular Repair Technique Lowered Early Dislocations in Primary Total Hip Arthroplasty Through a Posterior Approach

BACKGROUND

Dislocation is a challenging problem after total hip arthroplasty (THA). We sought to evaluate the incidence of early dislocation with 2 different posterior repair techniques after THA using a posterior approach.

METHODS

From September of 2008 to August of 2019, we evaluated 841 THAs performed by a single surgeon using a posterior approach. Before November of 2015, the capsule was repaired to the greater trochanter (group 1, 605 patients). Starting November 2015, the posterior capsule was repaired in a side-to-side fashion (direct soft-tissue repair) (group 2, 236 patients). There was a mean follow-up of 31.1 months (range, 2.5-122.5 months). A multivariable logistic regression model was constructed to assess the impact of baseline patient and operative factors on the dislocation rate.

RESULTS

There were 22 dislocations, all of which occurred in group 1. There were no dislocations in group 2. After adjusting for patient and operative factors, the direct soft-tissue repair had a large impact on the overall multivariable model as indicated by its effect likelihood ratio of 10.33 (P = .001); however, the odds ratio was not calculable for this factor, given that there were no dislocations in hips with direct soft-tissue repair. Increasing age was associated with an increased odds of dislocation (odds ratio, 1.04, P = .017), with an effect likelihood ratio of 6.25 (P = .012).

CONCLUSIONS

Switching from a capsular repair to the greater trochanter to a side-to-side capsular repair was associated with a decreased rate of dislocation in primary THA through a posterior approach.