Do Knee Osteoarthritis Patterns Affect Patient-Reported Outcomes in Total Knee Arthroplasty? Results From an International Multicenter Prospective Study With 3-Year Follow-Up

BackgroundThe aim of this multicenter study is to answer (1) Does patellofemoral osteoarthritis (OA) affect preoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) scores in total knee arthroplasty (TKA)? and (2) Do different OA patterns affect preoperative and postoperative KOOS scores in TKA?MethodsThis international, multicenter prospective study examined 384 TKA patients. Compartmental OA was divided into (1) medial, (2) medial + patellofemoral, (3) lateral, (4) lateral + patellofemoral, (5) medial + lateral (bicompartmental), and (6) medial + lateral + patellofemoral (tricompartmental), based on preoperative anterior-posterior and lateral ± skyline radiographs with Kellgren-Lawrence grade III-IV and joint space width <2.5 mm. KOOS was collected preoperatively, 1 year postoperatively, and 3 years postoperatively. Higher KOOS score represented better clinical state, for example, higher KOOS Pain score indicated less pain.ResultsPatellofemoral OA had no effect on preoperative KOOS scores (P > .15). Compared to medial ± patellofemoral OA patients, bicompartmental/tricompartmental OA patients had less preoperative pain (KOOS Pain 7.4, P = .03) and higher daily function (KOOS-ADL [Activities of Daily Living] 7.1, P = .05), and higher 1-year postoperative daily function (KOOS-ADL 9.2, P = .03) and sports activity (KOOS Sports & Recreation Function 15.0, P = .04), while lateral ± patellofemoral OA patients had more symptoms (KOOS-Symptoms 7.0, P < .01), more pain (KOOS-Pain 7.5, P = .01), lower daily function (KOOS-ADL 9.3, P < .01), and lower quality of life (KOOS-QOL 9.0, P = .04), at 3 years postoperatively.ConclusionPatellofemoral OA does not affect medial ± lateral OA patients’ preoperative KOOS scores, challenging the importance of patellofemoral OA in TKA. Lateral ± patellofemoral OA patients have lower postoperative KOOS scores than medial/more progressed compartmental OA patients, indicating that patients with less common OA patterns present with unique surgical challenges. Further development of indications for and correct timing of TKA surgery in different patient subgroups is needed.     

Predictive factors for 12‐month outcome after anterior cruciate ligament reconstruction

There is a lack of knowledge regarding predictive factors for a successful clinical outcome after an anterior cruciate ligament (ACL) reconstruction. The aim was to investigate pre‐operative factors that may predict good outcomes as measured with the subscales Function in sports and recreation and Quality of life in Knee injury Osteoarthrithis Outcome Score (QOL‐KOOS), one‐leg hop test and Tegner Activity Scale 12 months after ACL reconstruction. Sixty‐four patients, operated with either patellar or hamstring tendon graft, were included. Demographics, range of motion, anterior knee laxity, pivot shift, muscle‐torques, anterior knee pain (AKP) and knee function were registered pre‐operatively and used in a multiple regression model. Results show less degree of AKP and low influence on knee function to be the most important predictors for good outcome in Sport/Rec‐KOOS (explained 31% of variances). Less AKP was in addition the most important predictor for QOL‐KOOS (14%). Patellar‐tendon graft, in favor of hamstring tendon graft, explained 8% of the improvement in the Tegner Activity Scale. In conclusion, a low degree of AKP was found to be the most important predictor for good clinical outcome 12 months after ACL reconstruction. Future studies, including psychological parameters, should use analyses that have the potential to control for independency between variables.     

Comparison of KOOS Scores of Middle-Aged Patients Undergoing Total Knee Arthroplasty to the General Dutch Population Using KOOS Percentile Curves: The LOAS Study

BackgroundWe aimed to investigate the application of the Knee Injury and Osteoarthritis Outcome Score (KOOS) percentile curves, using preoperative and postoperative data of patients with knee osteoarthritis undergoing total knee arthroplasty (TKA).MethodsWe used Longitudinal Leiden Orthopedics Outcomes of Osteo-Arthritis study data of patients between 45 and 65 years and undergoing primary TKA. KOOS scores (0-100) were obtained preoperatively and 6, 12, and 24 months after TKA. Preoperative knee radiographs were assessed according to Kellgren-Lawrence (KL) in a subset (37%) of patients. Comorbidities were self-reported using a standardized questionnaire. The median (interquartile range) population-level KOOS scores were plotted on previously developed population-based KOOS percentile curves. In addition, we assessed the application of the curves on patient level and investigated differences in scores between patients with preoperative KL scores ≤2 and ≥3 and presence (vs absence) of comorbidities.ResultsThe study population consisted of 853 patients (62% women, mean age 59 years, body mass index 30 kg/m²) with knee osteoarthritis undergoing primary TKA. Preoperatively, median KOOS scores of all subscales were at or below the 2.5^th percentile. Scores increased to approximately the 25^th percentile 12 months postoperatively. Greater improvements were observed in pain and less improvements in sport and recreational function and quality of life. Patients with higher preoperative KL scores and without comorbidities showed greater improvements.ConclusionThe KOOS percentile curves provided visual insights in knee complaints of patients relative to the general population. Furthermore, the KOOS percentile curves give insight in how preoperative patient characteristics are correlated with postoperative results.     

Age-Related Functional Decline Following Total Knee Arthroplasty: Risk Adjustment is Mandatory

Background

Patient-reported outcome measures (PROMs) are being used increasingly to determine the success of total knee arthroplasty (TKA). Our goal is to investigate whether advanced age is associated with lower PROM scores.

Minimal important change and minimum clinically important difference values of the KOOS-12 after total knee arthroplasty

PurposeThe minimal important change (minimal amount of change vs. baseline that a patient recognizes as a clinical change) and minimum clinically important difference (smallest difference between two measurements that are deemed important by patients) are important values to evaluate the clinical relevance of changes over time and differences between groups. This study aims to establish these values for the KOOS-12 at 1 year postoperatively.MethodsKOOS-12 scores were calculated from the full-length KOOS completed by patients undergoing primary TKA preoperatively and at 1 year follow up. Minimal important change (MIC) values were estimated using the anchor-based predictive modeling approach and adjustment for the large proportion of improved patients in the study cohort was performed. The MCID was defined as the difference in the mean change in the KOOS-12 between the ‘no improvement’ and ‘little improvement’ groups.ResultsA total of 352 patients (161 male:191 female) with an overall mean age of 67.9 years (standard deviation (SD) 8.2) and a mean body mass index of 31.4 kg/m² (SD 6.3) were included: 97.1% of patients reported an important improvement, 1.1% reported being about the same and 1.7% reported being importantly worse. The MIC improvement values were 11.5 for Pain, 13.7 for Function, 5.5 for Quality of Life (QoL) and 14.9 for the total KOOS-12 score. MCID values were 13.5 for Pain, 15.2 for Function, 8.0 for QoL and 11.1 for the total KOOS-12 score.ConclusionMIC of 14.9 and MCID of 11.1 established in this study can assist clinicians and researchers in the interpretation of within-group changes (MIC) and differences between groups (MCID) at 1 year after TKA.     

Validity of Combining History Elements and Physical Examination Tests to Diagnose Patellofemoral Pain

Objective

To assess the validity of diagnostic clusters combining history elements and physical examination tests to diagnose or exclude patellofemoral pain (PFP).

Prevalence and Predictors of Symptom Resolution and Functional Restoration in the Index Knee After Knee Arthroplasty: A Longitudinal Study

Objectives

To determine the prevalence of a 1- to 2-year postsurgical pain-free state and pain plus symptom-free state as well as functional restoration after knee arthroplasty (KA) and to identify predictors of these outcomes.

Knee Arthroplasty Patients Predicted Versus Actual Recovery: What Are Their Expectations About Time of Recovery After Surgery and How Long Before They Can Do the Tasks They Want to Do?

Objectives

(1) To determine evidence-based guidance for the length of time to return to specific valued functional and leisure activities after knee arthroplasty (KA). (2) To determine what patients feel are the most important functional or leisure activities to recover after KA. (3) To collect information about patients’ expectations and compare them to the actual time it takes to return.