What Are Drivers of Readmission for Readmission-Requiring Venous Thromboembolic Events After Primary Total Hip Arthroplasty? An Analysis of 544,443 Cases

BackgroundVenous thromboembolism (VTE) is a potential postoperative complication after total hip arthroplasty (THA). These events present with a range of severity, and some require readmission. The present study aimed to identify unexplored risk factors for severe VTE that lead to hospital readmission.MethodsThe Agency of Healthcare Research and Quality’s National Readmissions Database was retrospectively queried for all patients who underwent primary THA (January 2016 to December 2018). Study population included patients who were readmitted for VTE within 90 days after an elective THA. Bivariate and multivariate regression analyses were performed using patient demographics, insurance status, elective nature of the surgery, healthcare institution characteristics, and baseline comorbidities.ResultsHigher risk of readmission for VTE was evident among elderly (71-80 years vs <40 years: odds ratio [OR] 1.7, 95% confidence interval [CI] 1.3-2.2, P = .0002), male patients (OR 1.2, 95% CI 1.2-1.3). Nonelective THAs were associated with markedly higher odds of readmission for VTE (OR 20.5, 95% CI 18.9-22.2), peripheral vascular disease (OR 1.2, 95% CI 1.1-1.4), lymphoma (OR 1.5, 95% CI 1.1-2.1), metastatic cancer (OR 1.8, 95% CI 1.4-2.2), obesity (OR 1.5, 95% CI 1.4-1.6), and fluid-electrolyte imbalance (OR 1.1, 95% CI 1.0-1.2). Home health care (OR 0.8, 95% CI 0.7-0.8) and discharge to skilled nursing facility (OR 0.7, 95% CI 0.7-0.8) had lower odds of readmission for VTE vs unsupervised home discharge, while insurance type was not a significant driver(P > .05).ConclusionOne in 135 THA patients is likely to experience a VTE requiring readmission after THA. Male patients, age >70 years, and specific baseline comorbidities increase such risk. Furthermore, discharge to a supervised setting mitigated the risk of VTE requiring readmission compared to unsupervised discharge. As VTE prophylaxis protocols continue to evolve, these patients may require optimized perioperative care pathways to mitigate VTE complications.     

Are Patients With a History of Septic Arthritis Undergoing Total Knee Arthroplasty at Higher Risk for Revision Surgery? A Single-Center Study

BackgroundThe decision to perform a total knee arthroplasty (TKA) on a previously infected knee is made complicated by the higher risk for both a periprosthetic joint infection (PJI) and early failure. There is currently no standard in the treatment strategy for this group of patients. We here report the outcomes of performing a primary TKA on patients with a prior septic knee arthritis. The aim of our study is to analyze the survival rates of patients with a history of septic arthritis undergoing TKA.MethodsFrom 2010 to 2018, all patients treated in our institution with a minimum follow-up of 1 year, who have previous histories of knee joint infections and underwent a primary TKA were included in the study. All patients underwent the same surgical protocol and were given systemic and local antibiotic treatment.ResultsOf the 68 knees, there were 4 surgical revisions (5.9%). These included 2 septic revisions due to PJI (2.9%), 1 open arthrolysis for arthrofibrosis (1.5%), and 1 aseptic revision for implant loosening (1.5%). Sixty-four (64) knees (94%) had survived without any surgical interventions and the Kaplan-Meier analysis demonstrated an overall survivorship free from PJI of 97.1% at a mean of 5 years (range 1-9, standard deviation ±2.5 years).ConclusionTKA is a suitable option for patients with a prior septic arthritis of the knee, provided that proper surgical technique and the utilization of systemic and local antibiotics are employed.Level of EvidenceLevel III, therapeutic study.     

Does Aseptic Revision Risk Differ for Primary Total Knee Arthroplasty Patients Who Have and Do not Have a Prior Primary or Revision Arthroplasty?

BackgroundWe sought to evaluate the risk of aseptic revision in total knee arthroplasty (TKA) patients who have and do not have a history of primary or revision arthroplasty of a different major joint.MethodsWe conducted a matched cohort study using data from Kaiser Permanente’s arthroplasty registries. Patients who underwent primary unilateral TKA (index knee) were identified (2009-2018). Two matches based on exposure history were performed: (1) 33,714 TKAs with a history of primary arthroplasty of a different joint (contralateral knee, either hip, and/or either shoulder) were matched to 67,121 TKAs without an arthroplasty history and (2) 597 TKAs with a history of aseptic revision in a different joint were matched to 1,190 TKAs with a history of a prior arthroplasty in a different joint, but without any revision. After the matches were performed, Cox regressions were used to evaluate aseptic revision risk of the index knee using the no history groups as the reference in regression models.ResultsNo difference in aseptic revision risk for the index knee was observed when comparing patients who had a prior primary arthroplasty in a different joint to those who did not have an arthroplasty history (hazard ratio = 0.95, 95% CI = 0.86-1.06). Those patients who did not have any prior aseptic revision history in a different joint had higher risk of aseptic revision in the index knee (hazard ratio = 2.06, 95% CI = 1.17-3.63).ConclusionPatients who had a prior revision history had over a 2-fold higher risk of aseptic revision in the index knee, warranting close surveillance of these patients.Level of EvidenceLevel III.     

Are We Appropriately Compensated by Relative Value Units for Primary vs Revision Total Hip Arthroplasty?

Background

Relative value units (RVUs) are used to evaluate the effort required for providing a service to patients in order to determine compensation. Thus, more complicated cases, like revision arthroplasty cases, should yield a greater compensation. However, there are limited data comparing RVUs to the time required to complete the service. Therefore, the purpose of this study is to compare the (1) mean RVUs, (2) mean operative times, and (3) mean RVU/minute between primary and revision total hip arthroplasty (THA) and (4) perform an individualized idealized surgeon annual cost difference analysis.

Are Ceramic-on-ceramic Bearings in Total Hip Arthroplasty Associated With Reduced Revision Risk for Late Dislocation?

Background

Dislocation is a major complication after primary total hip arthroplasty (THA), but little is known about the potential relationships between bearing materials and risk of dislocation. Dislocation within the first year after surgery is typically related to either surgical error or patient inattention to precautions, but the reasons for dislocation after the first year are often unclear, and whether ceramic bearings are associated with an increased or decreased likelihood of late dislocation is controversial.

Questions/purposes

The purpose of this study was to use a national registry to assess whether the choice of bearings–metal-on-polyethylene (MoP), ceramic-on-polyethylene (CoP), ceramic-on-ceramic (CoC), or metal-on-metal (MoM)–is associated with differences in the risk of late dislocation.

Methods

Data from primary THAs were extracted from the New Zealand Joint Registry over a 10-year period. The mean age of patients was 69 years (SD ± 12 years), and 53% were women. The median followup in this population was 7 years (range, 1–13 years). The surgical approach used was posterior in 66% of THAs, lateral in 29%, and anterior in 5%. The primary endpoint was late revision for dislocation with “late” defined as greater than 1 year postoperatively. A total of 73,386 hips were available for analysis: 65% MoP, 17% CoP, 10% CoC, and 7% MoM. In general, patients receiving CoC and MoM bearings were younger compared with patients receiving CoP and MoP bearings.

Results

Four percent of the hips were revised (3130 THAs); 867 THAs were revised for dislocation. Four hundred seventy THAs were revised for dislocation after the first postoperative year. After adjusting for head size, age, and surgical approach, only CoP (hazard ratio [HR], 2.10; p = 0.021) demonstrated a higher proportion of revision, whereas MoP did not (HR, 1.76; 95% p = 0.075). There were no differences of revisions for dislocation in the CoC (HR, 1.60; p = 0.092) and MoM cohorts (HR, 1.54; p = 0.081).

Conclusions

Dislocation is a common reason for revision after THA. The relationships between bearing materials and risk of revision for late dislocation remain controversial. This large registry study demonstrated that bearing surface had little association with the incidence of late dislocation. Future studies with longer followups should continue to investigate this question.

Level of Evidence

Level III, therapeutic study.     

Are Bilateral Total Joint Arthroplasty Patients at a Higher Risk of Developing Pulmonary Embolism Following Total Hip and Knee Surgery?

Despite developments in prophylactic methods, venous thromboembolism (VTE) continues to be a serious complication following total joint arthroplasty. The new AAOS/ACCP guidelines on preventing pulmonary embolism (PE) after total hip/knee arthroplasty (THA/TKA) do not make specific recommendations for bilateral vs. unilateral procedures. In-patient PE rates were examined for patients undergoing unilateral or simultaneous bilateral TKA/THA at our institution in 2011. Of the 7,437 THA/TKA surgeries completed at our institution in 2011, 36 patients suffered from PE (0.48%). The rate of PE for unilateral TKA was 0.61% vs. 1.87% for bilateral (P < 0.001) and for unilateral THA was 0.17% vs. 0.52% for bilateral THA. Despite patients being screened before being cleared to undergo bilateral THA/TKA, they remain at higher risk for VTE.     

Modifiable Risk Factors Are Common in Early Revision Hip and Knee Arthroplasty

Background

Obesity, smoking, uncontrolled diabetes, and poor dental health are modifiable risk factors for revision total joint arthroplasty. To protect patients from revision surgery while also reducing cost, some joint arthroplasty practices use these conditions as contraindications until they are improved. However, this practice is variable among joint arthroplasty surgeons. We hypothesize that a relatively high rate of revision arthroplasty patients had modifiable risk factors at the time of primary surgery.

What Are the Risk Factors for Revision Surgery After Hip Arthroscopy for Femoroacetabular Impingement at 7-year Followup?

Clinical Orthopaedics and Related Research® - In recent years, surgical treatment of symptomatic femoroacetabular impingement (FAI) has been increasingly performed using arthroscopy. Bony...     

Are Gender,Comorbidity, and Obesity Risk Factors for Postoperative Periprosthetic Fractures After Primary Total Hip Arthroplasty?

We studied the frequency and patient risk factors for postoperative periprosthetic fractures after primary total hip arthroplasty (THA). With a mean follow-up of 6.3 years, 305 postoperative periprosthetic fractures occurred in 14?065 primary THAs. In multivariable-adjusted Cox regression analyses, female gender (hazard ratio [HR], 1.48; 95% confidence interval [CI], 1.17-1.88), Deyo-Charlson comorbidity score of 2 (HR, 1.74 for score of 2; 95% CI, 1.25-2.43) or 3 or higher (HR, 1.71; 95% CI, 1.26-2.32), and American Society of Anesthesiologist class of 2 (HR, 1.84; 95% CI, 0.90-3.76) or 3 (HR, 2.45; 95% CI, 1.18-5.1) or 4 or higher (HR, 2.68; 95% CI, 0.70-10.28) were significantly associated with higher risk/hazard, and cemented implant, with lower hazard (HR, 0.68; 95% CI, 0.54-0.87) of postoperative periprosthetic fractures. Interventions targeted at optimizing comorbidity management may decrease postoperative fractures after THA.     

Leg-Length Discrepancy After Revision Hip Arthroplasty: Are Modular Stems Superior?

We retrospectively reviewed data for 79 consecutive patients who underwent revision hip arthroplasty using cementless femoral stems at our center between September 2008 and November 2010. Two cohorts were included, one using MP (modular) femoral stems and the other using Wagner (monoblock) femoral stems. We assessed leg-length discrepancy (LLD) before and after revision and compared the occurrence of leg-length inequality between the 2 cohorts. We found that the incidence of LLD was high in revision hip arthroplasty and that leg shortening was more common than lengthening. Both acetabular and femoral sides contributed to postoperative LLD. Appropriate placement of the femoral components was most critical in adjusting LLD. We also found that compared with monoblock stems, modular stems made adjustment of postoperative leg length easier.     

Survivorship and Risk Factors for Re-Revision after Aseptic Revision Total Hip Arthroplasty in Patients Aged ≤55 Years

BackgroundThere is a relative paucity of literature on the outcomes after revision total hip arthroplasty (rTHA) in young patients. This study reports the survivorship and risk factors for re-revision in patients aged ≤55 years.MethodsWe identified 354 patients undergoing aseptic nononcologic rTHA at mean follow-up of 5 years after revision, with mean age of 48 years, body mass index of 28 kg/m², and 64% female. Thirty-five (10%) patients underwent at least 1 previous rTHA. The main indications for rTHA included wear/osteolysis (21%), adverse local tissue reaction (21%), recurrent instability (20%), acetabular loosening (16%), and femoral loosening (7%); and included acetabular component-only rTHA in 149 patients (42%), femoral component-only rTHA in 46 patients (13%), both component rTHA in 44 patients (12%), and head/liner exchanges in patients 115 (33%). The Kaplan-Meier method was used to measure survivorship free from re-revision THA, and multivariate regression was used to identify risk factors for re-revision THA.ResultsSixty-two patients (18%) underwent re-revision THA at the mean time of 2.5 years, most commonly for instability (37%), aseptic loosening (27%), and prosthetic joint infection (15%). The rTHA survivorship from all-cause re-revision and reoperation was 83% and 79% at 5 years, respectively. Multivariate analysis demonstrated that patients undergoing femoral component only (hazard ratio 4.8, P = .014) and head/liner exchange rTHA (hazard ratio 2.5, P = .022) as risk factors for re-revision THA.ConclusionAbout 1 in 5 patients aged ≤55 years undergoing rTHA required re-revision THA at 5 years, most commonly for instability. The highest risk group included patients undergoing head/liner exchanges and isolated femoral component revisions.     

Understanding Readmission After Primary Total Hip and Knee Arthroplasty: Who’s at Risk?

Readmission has been cited as an important quality measure in the Patient Protection and Affordable Care Act. We queried an electronic database for all patients who underwent Total Hip Arthroplasty or Total Knee Arthroplasty at our institution from 2006 to 2010 and identified those readmitted within 90 days of surgery, reviewed their demographic and clinical data, and performed a multivariable logistic regression analysis to determine significant risk factors. The overall 90-day readmission rate was 7.8%. The most common readmission diagnoses were related to infection and procedure-related complications. An increased likelihood of readmission was found with coronary artery disease, diabetes, increased LOS, underweight status, obese status, age (over 80 or under 50), and Medicare. Procedure-related complications and wound complications accounted for more readmissions than any single medical complication.     

Stratifying Venous Thromboembolism Risk in Arthroplasty: Do High-Risk Patients Exist?

BackgroundWhile there are many possible complications associated with total joint arthroplasty (TJA), venous thromboembolism (VTE) is both frequent and potentially severe. Despite this importance, there are inconsistent recommendations for prophylaxis based on patient risk factors.MethodsA predictive model was constructed to compare low-molecular-weight heparin(LMWH) and aspirin (ASA) for prevention of VTE-associated complications following TJA.The model used risks from prior prophylaxis studies to estimate the risk of developing a symptomatic deep vein thrombosis, pulmonary embolism, thrombocytopenia, and operative or nonoperative site bleeding. We also evaluated the progression to 4 possible final health states: postphlebitis syndrome, intracranial hemorrhage, death, or baseline health. Within published ranges, we selected assumptions that were favorable to LMWH such that these analyses represent a best case scenario for LMWH or an alternative more aggressive low-molecular-weight heparin alternative (LMWHA). Events and outcomes were assigned quality-adjusted life-year (QALY) losses according to prior studies to determine the effect on patients’ outcomes for ASA and LMWHA prophylaxis.ResultsAssessing VTE risk populations from 0.2% to 2% with life expectancies ranging from 5 to 40 years postoperatively, patients with a risk ratio less than 3.7 showed increased expected QALY with ASA compared to LMWHA. For patients with a baseline VTE risk of 1% and a 15 year life expectancy, a risk ratio of 13.4 was needed to identify patients that would benefit from LMWHA. With life expectancy increased to 30 years, the risk ratio needed to idetify these patients was 7.4.ConclusionPatients undergoing TJA should receive ASA chemoprophylaxis in nearly all situations, unless the patient has a significantly increased VTE risk compared to the baseline population and a long life expectancy.     

Are Routine Postoperative Laboratory Tests Necessary After Primary Total Hip Arthroplasty?

BackgroundRecently, the practice of ordering routine postoperative laboratory tests in primary total hip arthroplasty (THA) has been challenged. This study aimed to evaluate the utility of routine postoperative laboratory tests after primary elective THA in an Asian population and identify the risk factors associated with abnormal postoperative laboratory test–related intervention.MethodsWe retrospectively reviewed 395 consecutive patients who underwent primary elective THA at a single tertiary academic center. Patient clinical information and laboratory test results were collected for analysis.ResultsA total of 349 (88.4%) patients had abnormal postoperative laboratory test results; most patients had anemia and hypoalbuminemia. Twenty-seven (6.8%) patients received clinical intervention. Of the 307 (77.7%) patients with postoperative anemia, 7 patients received blood transfusion. Factors associated with transfusion were female gender, low body mass index, long operation time, and low preoperative hemoglobin levels. Of the 149 (37.7%) patients with postoperative hypoalbuminemia, 16 received albumin supplementation. Factors associated with albumin supplementation were female gender, long operation time, and low preoperative albumin levels. Although 36 patients had abnormal postoperative creatinine, only 1 patient required specialist consultation. For electrolyte abnormalities, hyponatremia was noted; however, no patient received sodium supplementation. Moreover, 14 patients developed hypokalemia, of which 6 required potassium supplementation; 163 patients had hypocalcemia, of which 2 received calcium supplementation.ConclusionRoutine laboratory tests after primary elective THA are unnecessary for most of the patients in modern clinical practice. However, for those with identified risk factors, postoperative laboratory tests still should be performed.