Increased collection of patient-reported outcome measures (PROM) in registries enables international comparison of patient-centered outcomes after knee and hip replacement. We aimed to investigate 1) variations in PROM improvement, 2) the possible confounding factor of BMI, and 3) differences in comorbidity distributions between registries.

Registries affiliated with the International Society of Arthroplasty Registries (ISAR) or OECD membership countries were invited to report aggregate EQ-5D, OKS, OHS, HOOS-PS and KOOS-PS values. Eligible patients underwent primary total, unilateral knee or hip replacement for osteoarthritis within three years and had completed PROMs preoperatively and either 6 or 12 months postoperatively, excluding patients with subsequent revisions. For each PROM cohort, Chi-square tests were performed for BMI distributions across registries and 12 predefined PROM strata (male/female, age 20-64/65-74/>75, high or low preoperative PROM scores). Comorbidity distributions were reported for available comorbidity indexes.

Thirteen registries from 9 countries contributed data, n~130000 knee (range 140 to 79848) and n~113000 hip (range 137 to 85281). Mean EQ-5D index values (10 registries) ranged from 0.53 to 0.71 (knee) and 0.50 to 0.70 (hips) preoperatively and 0.78 to 0.85 (knee) and 0.83 to 0.87 (hip) postoperatively. Mean OKS (6 registries) ranged from 19.3 to 23.6 preoperatively and 36.2 to 41.2 postoperatively. Mean OHS (7 registries) ranged from 18.0 to 23.2 preoperatively and 39.8 to 44.2 postoperatively. Four registries reported KOOS-PS and three reported HOOS-PS. Proportions of patients with BMI >30 ranged from 35 to 62% (10 knee registries) and 16 to 43% (11 hip registries). For both knee and hip registries, distributions of patients across six BMI categories differed significantly among registries (p30 were for patients in the youngest age groups (20 to 64 and 65 to 74 years) with the lowest baseline scores. Additionally, females with lowest preoperative PROM scores had highest BMI. These findings were echoed for the OHS and OKS cohorts. Proportions of patients with ASA scores ≥3 ranged from 7 to 42% (9 knee registries) and 6 to 35% (8 hip registries).

PROM-score improvement varies between international registries, which may be partially explained by differences in age, sex and preoperative scores. BMI and comorbidity may be relevant to adjust for.

Introduction

Patient satisfaction is an important outcome measure after total knee arthroplasty (TKA) and is the ultimate goal of surgery. However, patient satisfaction reflects a complex construct of the patient's personal expectations and preferences in addition to subjective evaluation of outcome after TKA. Multiple studies have found a patient dissatisfaction rate of approximately 20% at 1 year after TKA. The purpose of this study is to determine whether there is an association between a single-item validated TKA satisfaction score and patient-reported outcome measures (PROMs) at 3 time points (1, 2, and 5 years after TKA) and to determine if dissatisfaction rate after TKA varies over time.

Introduction

Several surgical approaches are available for elective total hip arthroplasty (THA) for osteoarthritis. While posterior surgical approaches are the most common, interest in a direct anterior (Hueter) approach is increasing because of alleged advantages in convalescence. However, no studies have examined differences in patient-reported global and condition-specific measures of health across multiple institutions. The ongoing Pulmonary Embolism Prevention after Hip and Knee Replacement (PEPPER) study is a PCORI-funded multicenter pragmatic clinical trial randomizing patients to three different antithrombotic regimens. We analyzed operative data from PEPPER to compare pre-post changes in validated patient-reported outcome measures after THA based on surgical approach.

Introduction

CMS is now publicly reporting 30-day readmission rates following total joint replacement (TJR) by hospital and is planning the collection of patient-reported function and pain after TJR. Nationally, 5% of patients are readmitted to the hospital after TJR for both medical and orthopedic-related issues. However, the relationship between readmission and functional gain and pain relief after TJR has not been evaluated.

Summary Statement

For RA patients undergoing TKR, the gain in function at 6 months following surgery is less than that experienced by OA patients; for THR, however, gains are similar in OA and RA patients.

Summary Statement

This data may help explain the variability in physical function after primary TKR as compared to primary THR.

Summary Statement

A prospective randomised evaluation of primary TKA utilizing patient specific instruments demonstrated great accuracy of bone resection, improved sagittal alignment and the potential to improve functional outcomes and reduce operating room costs when compared to standard TKA instrumentation.

Introduction:

Total knee replacement (TKR) and total hip replacement (THR) reliably relieve pain, restore function, and ensure mobility in patients with advanced joint arthritis; however these results are not uniform across all patient populations. Moreover, it is well established that knee replacement patients have outcomes inferior to those undergoing hip replacement procedures with lower rates of dissatisfaction with post-operative function and pain relief.

We compared baseline demographic and symptom profiles in patients from a US national cohort undergoing primary TKR and THR to determine whether differences in demographic make-up, pre-operative symptoms, or pre-existing co-morbidities might contribute to these differences observed post-operatively.

Introduction:

There is an increasing trend within the US for utilization of total knee replacement for patients who are still of working-age. Numerous causes have been suggested, ranging from greater participation in demanding sporting activities to the epidemic of obesity. A universal concern is that increased arthritis burden will lead to increased disabilty and unsustainable health-care costs both now and in the future with increasing rates of revision surgery in the years ahead. This raises the critical question: Are younger patients receiving knee replacement prematurely? To address this issue, we compared the severity of operative knee pain and functional status in younger versus older TKR patients, drawing upon a national research registry.

Purpose

Arthritis is the most common chronic illness in the United States. TKR provides reliable pain relief and improved function for patients with advanced knee arthritis. Total joint replacement now represents the greatest expense in the national healthcare budget. Surgical costs are driven by two key components: fixed and variable costs. Patient Specific Instruments™ (PSI, Zimmer, Warsaw, IN, USA) has the potential to reduce both fixed and variable costs by shortening operative time and reducing surgical instrumentation. However, PSI requires the added costs of pre-operative MRI scanning and fabrication of custom pin guides. Previous studies have shown reduction in operating room times and required instrumentation, but question the cost-effectiveness of the technology. Also, these studies failed to show improvement in coronal alignment, but call for additional studies to determine any improvement in clinical function and patient satisfaction. Our pilot study aims to compare the incremental PSI costs to fixed and variable OR cost savings, and compare meaningful patient and clinical outcomes between PSI and standard TKR surgeries.

The effect of pre-operative pain, physical function, mental function and multiple patient factors on patient outcome following TKR was examined.

After informed consent, 105 patients undergoing primary TKR completed preoperative SF-36 and WOMAC questionnaires and a Knee Society Score (KSS) was determined. These scores were repeated at 12 months. Patient data studied included age, gender, BMI and significant comorbid conditions such as diabetes, cardiac disease, and COPD. Statistical analysis included a univariate analysis, followed by a bivariate analysis and multiple regression analysis.

All physical dimensions of the SF-36, WOMAC and KSS showed highly significant improvements after one year. The KSS improved to a mean of 94.8 (p< 0.000001). For patients greater than 65 years of age, postoperative physical function was returned to normative scores for age matched controls. For patients less than 65, physical function did not reach age matched controls even though similar improvements in physical function were seen. Patients with lower physical function scores (PCS) pre-operatively showed greater improvement postoperatively yet did not reach the same absolute level of function as patients who had higher preoperative physical function. The mean PCS for men increased from 35 to 42, while for women it increased from 29 to 42 (p=0.042). Preoperative mental function (MCS) was a strong predictor of postoperative physical function. Patients with low preoperative MCS and one or more comorbid conditions were 10.1 times more likely to have a poor outcome following TKR.

Knowledge of preoperative physical function, mental function, gender, age and comorbid conditions improves prediction of post-operative physical function after TKR. Patients at high risk for little improvement following TKR are those with low preoperative mental function (MCS< 50) in addition to one or more comorbid conditions. These patients can be identified during the pre-operative period.