Informed consent for total knee arthroplasty: exploration of patient`s information acquisition and decision-making processes-a qualitative study.

BACKGROUND: Total knee arthroplasty (TKA) is an option for the treatment of knee osteoarthritis (OA). Patients have high expectations regarding the benefits of the actual operation. Patients can seek a second opinion on the indication for TKA. In a study, less than half of recommended TKAs were confirmed by the second opinion and conservative treatments are not fully utilized. Informed consent forms that are used in Germany usually do not meet the requirements to support informed decision-making. Our aim was to describe the process from the diagnosis of knee OA through the decision-making process to the informed consent process for TKA, and to understand when, how, and by whom decisions are made. Moreover, we wanted to describe patients' information needs and preferences about knee OA and its treatment, including TKA, and find out what information is provided. We also wanted to find out what information was important for decision-making and identify barriers and facilitators for the optimal use of evidence-based informed consent forms in practice. METHODS: We chose a qualitative approach and conducted semi-structured interviews with patients who were going to receive, have received, or have declined TKA, and with general practitioners (GP), office-based as well as orthopaedists and anaesthesiologists in clinics who obtain informed consent. The interviews were audio-recorded, transcribed and analysed using qualitative content analysis. RESULTS: We conducted interviews with 13 patients, three GPs, four office-based orthopaedists and seven doctors in clinics who had obtained informed consent. Information needs were modelled on subjective disease theory and information conveyed by the doctors. Patients in this sample predominantly made their decisions without having received sufficient information. Trust in doctors and experiences seemed to be more relevant in this sample than fact-based information. Office-based (GPs, orthopaedists) and orthopaedists in clinics had different understandings of their roles and expectations in terms of providing information. CONCLUSIONS: We were able to identify structural barriers and assumptions that hinder the implementation of evidence-based informed consent forms.

Sub-chondroplasty Reduces Pain, Improves Function and Delays the Conversion to Arthroplasty in Patients with Advanced Knee Osteoarthritis: A Stratified Meta-analysis and Quality Assessment.

There is an ongoing interest in alternatives to total knee arthroplasty, as a means to delay inevitable replacement. A possible, minimally invasive, alternative is a sub-chondroplasty, involving interosseous injection of bone substitute materials such as calcium phosphate (CaPo4), platelet-rich plasma (PRP), bone marrow aspirate concentrate (BMAC) or Injectable demineralized bone matrix (iDBM) into the subchondral bone. Eleven clinical trials were found, investigating the effectiveness of sub-chondroplasties performed using CaPo4, PRP, BMAC, and iDBM. A non-stratified and stratified meta-analysis of the included studies were conducted to test for confounding variables across the trials. Non-stratified analysis, regardless of injectable type, revealed a significant improvement in the average Visual Analog Scale (VAS) score and postoperative Knee Injury and Osteoarthritis Outcome Score (KOOS) in patients post sub-chondroplasty, as compared to baseline. This analysis demonstrates that the sub-chondroplasty procedure reduces pain, improves function, and has lower risk of conversion to arthroplasty. (Journal of Surgical Orthopaedic Advances 32(2):065-074, 2023).

The effects on joint functions of biplanar distal tubercle open-wedge high tibial osteotomy: A prospective study.

Distal tubercle biplanar open-wedge high tibial osteotomy (DT-BOWHTO) is a method frequently applied in the treatment of knee joint medial osteoarthritis. The aim of this study was to evaluate the radiological, clinical, and functional results of patients at 5 years after DT-BOWHTO surgery. The study included a total of 41 patients who underwent DT-BOWHTO, comprising 19 (46.3%) males and 22 (53.7%) females with a mean age of 55.54 ± 4.17 (45-63) years and mean follow-up of 66.76 ± 6.29 (60-81) months. Statistical comparisons were made of the preoperative and postoperative body mass index (BMI), modified Insall-Salvati index, Blackburn-Peel index, Kelgren-Lawrence classification (KLC), tibial slope angle, American Knee Society Functional Score (AKSFS), Clinical American Knee Society Score (CAKSS), visual analog scale (VAS) pain score, Tegner Functional Activity Score (TFAS), total corrected angular measurements (TCA), and the tibio-femoral varus angle. Compared to the preoperative values, no statistically significant difference was determined in the postoperative modified Insall-Salvati index, Blackburn-Peel index, and tibial slope angle values (P > .05), and a statistically significant difference was determined in the BMI, AKSFS, CAKSS, VAS, KLC, tibio-femoral varus angle, and TFAS values (P ≤ .001). When the preoperative and postoperative BMI values were compared in 3 groups of normal, overweight, and obese, there was found to be a statistically significant difference (P = .014). No significant correlation was determined between the BMI values and the VAS and KLC values (P > .05). No significant correlation was determined between the total corrected angular and the preoperative and postoperative pain, and clinical and functional knee scores (VAS, AKSFS, CAKSS, TFAS) (P > .05). DT-BOWHTO was seen to provide extremely good 5-year results in the knee clinical findings, pain severity, and functional results. As the patella height and tibial slope angle were not changed, this did not cause the development of osteoarthritis in the patellofemoral and tibiofemoral joints. Grafting and fixation of the tibial tubercle with additional screws in the application of DT-BOWHTO were not seen to make any additional contribution to the healing of the osteotomy line. There was no relationship between increased BMI, reduced pain, and increase in knee functions in patients who underwent DT-BOWHTO.

Preoperative high-intensity strength training combined with balance training can improve early outcomes after total knee arthroplasty.

BACKGROUND: To investigate the effect of preoperative high-intensity strength training combined with balance training on the knee function of end-stage knee osteoarthritis (KOA) patients after total knee arthroplasty (TKA). METHODS: A prospective study was conducted on end-stage KOA patients awaiting TKA. The patients were divided into an experimental group and a control group according to whether they received a preoperative training intervention. The differences in knee flexor-extensor strength, knee range of motion (ROM), timed up and go (TUG) test result, stair ascend/descend test result, Knee Society score (KSS) and Berg balance scale (BBS) score were assessed in both groups at baseline (T1), before operation (T2), 3 months after operation (T3), and 1 year after operation (T4). RESULTS: After high-intensity strength training and balance training, the knee flexor-extensor strength, TUG test result, stair ascend/descend test result, and KSS were all significantly improved at T2 in the experimental group over the control group. At T3, the knee ROM, knee flexor-extensor strength, TUG test result, BBS score, and KSS clinical and functional scores were all significantly superior in the experimental group. The experimental group enjoyed a superiority in KSS clinical and functional scores until T4. Group × time and between-group interactions were found in all assessment indicators in both groups (p < 0.01). CONCLUSION: Preoperative high-intensity strength training combined with balance training can enhance the knee flexor-extensor strength and balance of patients with end-stage KOA in the short term and help improve early outcomes after KOA. Trial registration ChiCTR2000032857, 2020-05-13.

Consequences of using poly-ether-ether-ketone versus traditional implant on tibial cement penetration and short-term clinical outcomes during total knee arthroplasty: a randomized controlled trial.

BACKGROUND: The use of poly-ether-ether-ketone (PEEK) prosthesis during total knee arthroplasty (TKA) is a relatively new concept. Several studies have suggested that the thickness of cement penetration during TKA may affect the stability of the implants. The present study aimed to compare the cement penetration and clinical performance between PEEK and traditional cobalt chromium molybdenum (CoCrMo) prosthesis during TKA. METHODS: This study was a randomized controlled trial with level I of evidence. A total of 48 patients were randomly assigned to either the PEEK group (n = 24) or the CoCrMo group (n = 24). Mean bone cement penetration under the tibial baseplate was assessed radiographically in four zones in the anteroposterior view and two zones in the lateral view, in accordance with the Knee Society Scoring System. Furthermore, parameters such as the Knee Society Score (KSS), visual analogue scale (VAS) scores, complications and survivorship at 1 year postoperatively were also compared. RESULTS: According to the results of this study, the mean bone cement penetration exhibited no significant difference between PEEK and CoCrMo groups (2.49 ± 0.61 mm vs. 2.53 ± 0.68 mm, p = 0.85). Additionally, there were no remarkable differences in the KSS clinical score, functional score, and VAS score between the two groups. Moreover, complications and survivorship were also statistically compared between the groups and presented no significant differences. CONCLUSIONS: Based on the current findings, it can be concluded that PEEK implant present similar bone cement penetration, short-term clinical outcomes, and survivorship with traditional CoCrMo implant in TKA without added complications. Trial registration Chinese Clinical Trial Registry (ChiCTR2100047563).

Early Tibial Baseplate Fracture After Medial Unicondylar Knee Arthroplasty: A Report of 2 Cases.

CASE: Implant failure after unicondylar knee arthroplasty (UKA) is a rare but well-described complication in the arthroplasty literature. However, there is a paucity of literature regarding rapid catastrophic failure of modern implant designs. This is a case report of 2 patients with early catastrophic failure of the tibial baseplate after UKA with a Stryker Restoris MultiCompartmental Knee System implant using Mako robotic assistance, both requiring revision to total knee arthroplasty. CONCLUSION: Improved awareness and understanding of early UKA tibial baseplate failure may help identify both patient and surgical risk factors that could help prevent further instances in the future.

Effect of knee arthroscopic debridement combined with peripatellar denervation on restoration of knee function in patients with knee osteoarthritis.

BACKGROUND: This research examines knee osteoarthritis (OA), a prevalent orthopedic disease marked by cartilage degeneration and chronic synovitis, leading to pain, restricted mobility, and eventual loss of knee function. Notably, patellofemoral osteoarthritis constitutes a significant proportion of knee OA cases. Our study aims to assess the impact of knee arthroscopic debridement coupled with peripatellar denervation on restoring knee function in OA patients and analyze the risk factors affecting treatment outcomes. By doing so, we hope to contribute to the informed selection of clinical treatment plans, addressing a disease that, if untreated, significantly impairs patients' quality of life. METHODS: A total of 211 patients with knee osteoarthritis treated in our hospital from June 2020 to June 2022 were analyzed retrospectively. Among them, 116 patients received arthroscopic knee debridement treatment alone as the control group, and 95 in the observation group were combined with denervation treatment based on the control group. The clinical efficacy of the two groups of patients after treatment was evaluated, and patients' pain was counted using the pain visual analogue score (VAS) method. The knee range of motion (ROM) was used to count the mobility of the patients and to compare the operative time, intraoperative perfusion volume, and length of stay between the two groups. According to the effectiveness after treatment, patients were divided into the improvement group (effective + markedly effective) and the non-improvement group, and the risk factors affecting the clinical efficacy of patients after treatment were analyzed by logistic regression. RESULTS: The total treatment efficiency of patients in the control group was lower than that of those in the observation group (P < 0.05). There was no difference in intraoperative perfusion volume and length of stay between patients in both groups (P > 0.05). However, the operative time was shorter in the control group compared with that in the observation group (P < 0.001). The post-treatment VAS scores of patients in the observation group were lower than those in the control group, while the ROM scores were higher than those of the control group (P < 0.001). Age, BMI, and preoperative VAS score were found to be independent risk factors for patient outcome by logistic regression analysis (P < 0.05). CONCLUSION: knee arthroscopic debridement combined with peripatellar denervation has a significant improvement in the restoration of knee function in patients with knee osteoarthritis and reduces their level of pain.

Sex-Based Differences in the Utilization of Shoulder, Hip, and Knee Arthroplasty.

INTRODUCTION: Studies show that females have a higher prevalence of osteoarthritis, worse symptoms, but lower rates of joint replacement surgery (JRS). The reason for this remains unknown. METHODS: A database of JRS candidates was created for patients seen in 2019 at an academic center. Demographics, Kellgren-Lawrence grades, symptom duration, visual analogue pain score, Charlson Comorbidity Index, and nonsurgical treatments were collected. Patients who were offered but declined surgery were invited to focus groups. Two independent sample t-tests, Mann-Whitney U tests, and chi-square tests were used for continuous, scored, and categorical variables, respectively, with two-tailed significance <0.05. Qualitative, code-based analysis was performed for the focus groups. RESULTS: The cohort included 321 patients (81 shoulder, 59 hip, and 181 knee) including 199 females (62.0%). There were no differences in proportions of females versus males who underwent JRS or in nonsurgical treatments. Female shoulder arthritis patients were older, had a higher visual analogue pain score, and had a higher Charlson Comorbidity Index. In focus groups, males prioritized waiting for technology advancements to return to an active lifestyle, whereas females experienced negative provider interactions, self-advocated for treatment, concerned about pain, and believed that their sex affected their treatment. DISCUSSION: We found equal utilization of JRS at our institution. However, female patients experienced unique barriers to surgery.

[Periarticular knee osteotomies for pre-arthritic deformities in the frontal plane : Indications and surgical techniques]. / Frontale kniegelenksnahe Umstellungsosteotomien bei präarthrotischen Deformitäten : Indikationen und Operationstechniken.

BACKGROUND: Currently, periarticular knee joint osteotomies are an integral part of the treatment of early arthritic deformities in the knee joint. DIAGNOSTICS: Analysis of the deformity is performed with a standardized full-leg standing x­ray of both legs, as well as a lateral x­ray of the knee joint that includes 2/3 of the proximal tibial shaft. An MRI examination of the knee joint is obtained to assess the articular cartilage, the ligaments and menisci. Torsion angle measurements with the CT/MRT supplement the diagnostics if necessary. Knowledge of normal physiological values and their standard deviations of the mechanical leg axis and the joint angles around the knee is obligatory. THERAPY: The osteotomy is performed as close as possible to the femoral and/or tibial deformity. Postsurgical deformities including pathological patella position or a significant difference in leg length must be prevented. A description of proximal tibia opening or closing wedge osteotomies based on the nomenclature of the joint angles by Paley is presented. The indications for the various osteotomy techniques in the coronary plane are discussed in detail.

Diagnosing knee osteoarthritis in patients, differences between general practitioners and orthopedic surgeons: a retrospective cohort study.

BACKGROUND: knee complaints are one of the most common reasons to consult the general practitioners in the Netherlands and contribute to the increasing burden on general practitioners. A proportion of patients that are referred to orthopedic outpatient clinics are potentially referred unnecessarily. We believe osteoarthritis is not always considered by general practitioners as the cause of atraumatic knee complaints. This may impede early recognition and timely care of osteoarthritis complaints and lead to unnecessary referrals. METHODS: the aim of this study was to compare the frequency of (differential) diagnosis of osteoarthritis mentioned in referral letters of general practitioners with the frequency of osteoarthritis mentioned as orthopedic diagnosis at the outpatient clinic. Therefore we conducted a retrospective cohort study based on data collected from referral letters and the corresponding outpatient clinic reports of patients with atraumatic knee complaints of 45 years or older referred to a regional hospital in Nijmegen, The Netherlands in the period from 1-6-2019 until 1-01-2020. RESULTS: a total of 292 referral letters were included. In the younger aged patients (45-54 years) osteoarthritis was mentioned less frequent and meniscal lesions were mentioned more frequent in referral letters when compared to diagnoses made at the outpatient clinic. Differences in differential diagnosis of osteoarthritis as well as meniscal lesions between orthopedic surgeon and general practitioners were found (both p < 0.001, McNemar). Matching diagnoses were present in 58.2% when all referral letters were analyzed (n = 292) and 75.2% when only referrals containing a differential diagnosis were analyzed (n = 226). Matching diagnoses were present in 31.6% in the younger age categories (45-54 years). A linear trend showing fewer matching diagnoses in younger patient categories was observed (p < 0.001). CONCLUSIONS: Osteoarthritis was less frequently mentioned in general practitioner referral letters among the differential diagnosis then it was diagnosed at the outpatient clinic, especially in younger patients (45-54 years). Also matching diagnoses in younger patients were evidently lower than in older patients, partly explained by underdiagnosing of osteoarthritis in younger patients in this cohort. Better recognition of osteoarthritis in younger patients and changing the diagnostic approach of general practitioners might improve efficacy in knee care. Future research should focus on the effectiveness of musculoskeletal triage, the need for multidisciplinary educational programs for patients and promotion of conservative treatment modalities among general practitioners.

Self-aligned Technique for Tibial Component Placement in Total Knee Arthroplasty Lessening Rotational Malalignment in Measured Resection and Gap-Balancing Techniques.

Background: Femorotibial rotational mismatch can occur when there is a rotational malalignment in either the tibial or femoral component. Self-aligned technique was proposed for orienting the tibial component in relation to the femoral prosthesis to reduce rotational malalignment between components. Therefore, we aimed to compare the rotational angle of the femoral and tibial components, as well as the femorotibial rotational mismatch, between the measured resection (MR) and gap-balancing (GB) techniques when combined with a self-aligned technique. Methods: We conducted a nonrandomized, experimental study with 50 patients in each group. The femoral rotation was set to 3° external rotation relative to the posterior condylar axis in the MR group, whereas the femur was resected to obtain an optimal rectangular flexion gap in the GB group. The self-aligned method was used to set the tibial rotation in both groups. Femoral and tibial rotational alignments were evaluated compared to a surgical transepicondylar axis of the femur using computed tomography. Rotational mismatch was defined as a difference between the femoral and tibial rotational alignments. A positive value indicated that the component was externally rotated relative to the reference line. Results: The femoral component of the GB group was more externally rotated than that of the MR group (1.52° ± 1.31° vs 0.28° ± 1.16°, p < 0.001). However, the tibial rotational angle was not statistically significantly different between the MR and GB groups (1.28° ± 3.17° vs. 1.86° ± 2.81°, p = 0.220), and the rotational mismatch was 1.00° ± 3.28° and 0.34° ± 2.71°, respectively (p = 0.306). Conclusions: Although the femoral component of the GB group had a greater degree of external rotation than that of the MR group, the use of a self-aligned technique for tibial component placement resulted in no significant difference in tibial rotational alignment or rotational mismatch. This technique helps align the tibial component with the femoral component and lessen the degree of rotational malalignment in both the MR and GB techniques.

Kinematically Aligned Oxford Unicompartmental Knee Arthroplasty Using the Microplasty Instrumentation System.

This technical note demonstrates kinematically aligned Oxford unicompartmental knee arthroplasty using the Microplasty instrumentation system with custom-made devices. The medial joint line is evaluated preoperatively; if it is aligned and parallel with the lateral joint line, they are considered to comprise the coronal knee joint line (CJL). In this case, the coronal inclination of a spoon gauge inserted into the medial joint space indicates the CJL. Otherwise, an accessory spoon is inserted and connected to the medial spoon to refer to the posterior condylar line, which is considered the CJL. The tibial cutting block is then connected without changing the inclination of the spoon and the coronal tilt of the tibial extramedullary rod is adjusted, which is implemented with a custom-made ankle yoke. The remainder of the steps is then identical to the conventional Microplasty procedure. This technique can imitate the cutting line to the CJL, which might be considered ideal from mechanical and kinematic perspectives.

Comparison of conventional and cooled radiofrequency treatment of the genicular nerves versus sham procedure for patients with chronic knee pain: protocol for a multicentre, double-blind, randomised controlled trial (COGENIUS).

INTRODUCTION: The prevalence of chronic knee pain is increasing. Osteoarthritis (OA) and persistent postsurgical pain (PPSP) are two important causes of knee pain. Chronic knee pain is primarily treated with medications, physiotherapy, life-style changes and intra-articular infiltrations. A radiofrequency treatment (RF) of the genicular nerves is a therapeutical option for refractory knee pain. This study investigates the effectiveness and cost-effectiveness of conventional and cooled RF in patients suffering from chronic, therapy resistant, moderate to severe knee pain due to OA and PPSP. METHODS AND ANALYSIS: The COGENIUS trial is a double-blinded, randomised controlled trial with 2-year follow-up. Patients and outcome assessors are blinded. Patients will be recruited and treated in Belgium and the Netherlands. All PPSP after a total knee prothesis and OA patients (grades 2-4) will undergo a run-in period of 1-3 months where conservative treatment will be optimised. After the run-in period, 200 patient per group will be randomised to conventional RF, cooled RF or a sham procedure following a 2:2:1 ratio. The analysis will include a comparison of the effectiveness of each RF treatment with the sham procedure and secondarily between conventional and cooled RF. All comparisons will be made for each indication separately. The primary outcome is the Western Ontario and McMaster Universities Osteoarthritis Index score at 6 months. Other outcomes include knee pain, physical functionality, health-related quality of life, emotional health, medication use, healthcare and societal cost and adverse events up to 24 months postintervention. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Ethics Committee of the University of Antwerp (Number Project ID 3069-Edge 002190-BUN B3002022000025), the Ethics committee of Maastricht University (Number NL80503.068.22-METC22-023) and the Ethics committee of all participating hospitals. Results of the study will be published in international peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05407610.

Combined femoral and tibial component total knee arthroplasty device rotation measurement is reliable and predicts clinical outcome.

BACKGROUND: The optimal total knee arthroplasty (TKA) rotational alignment and how best to obtain and measure it are debatable. The aim was to analyse the reliability of the Berger femoral, three different tibial and four different combined two-dimensional computer tomography (2D-CT) TKA component rotation measurements, and to ascertain which rotational values best predict a successful clinical outcome. METHODS: The 2D-CT scans were obtained post-operatively on 60 patients who had TKA. We determined one femoral [Berger's femoral angle (BFA)], three tibial [Berger's tibial angle (BTA), anatomical tibial angle (ATA) and bimalleolar posterior tibial component angle (BM_PTCA)] and four combined [transepicondylar posterior tibial component angle (TE_PTCA), bicondylar posterior tibial component angle (BC_PTCA, transepicondylar bimalleolar angle (TE_BM) and bicondylar bimalleolar angle (BC_BM)] TKA rotation angles. We made all measures in 23 patients twice by three observers and determined inter- and intra-observer agreement using the Bland-Altman plot method. We analysed measures of 55 patients using the area under the ROC curve (AUC) analysis to ascertain the discriminative capacity of BFA, ATA, TE_PTCA and BC_PTCA for predicting a successful clinical outcome according to the Knee Society Score (KSS) threshold. RESULTS: ATA showed the smaller inter- and intra-observer average of differences (-0.1° and 1.6°, respectively) of the studied methods followed by BFA (-0.9° and 1.4°), TE_PTCA (-2.1° and 2.7°) and BC_PTCA (-0.5° and 1.8°). BFA (-4° to 2.1° and -6.1° to 8.8°) and BC_PTCA (-4.4° to 3.4° and -7.9° to 4.4°) showed the narrower inter- and intra-observer limits of agreement. A TKA device rotation (BC_PTCA) < 0.8° of external rotation (ER) predicted a KSS and KSS knee successful outcome, and < 3.8° ER for KSS functional (AUC = 0.889; 0.907 and 0.764, respectively). BFA and ATA < 0.9° ER and < 3.9° internal rotation (IR) predicted a successful KSS knee outcome (AUC = 0.796 and 0.889, respectively). CONCLUSION: The ATA tibial component rotation measurement was the most reliable of those studied. BFA, TE_PTCA and BC_PTCA were reliable measures for TKA femoral and combined rotation. The presence of a minimal rotation between the TKA components (BC_PTCA) and a small femoral ER or tibial IR predicted a successful KSS outcome.

Total Knee Arthroplasty Using Computer-Assisted Navigation in a Patient with Nail-Patella Syndrome: A Case Report.

CASE: Nail-patella syndrome (NPS) is a genetic disorder causing anatomical abnormalities about the knee, including significant patellar hypoplasia. We present a case of a patient with NPS and severe knee osteoarthritis undergoing computer-assisted total knee arthroplasty (TKA). Several intraoperative anatomical challenges were appreciated. Postoperatively, the patient developed arthrofibrosis requiring manipulation; however, his final outcome was favorable. CONCLUSION: Computer assistance may improve precision in patients with NPS undergoing TKA, but surgeons must be aware of the associated anatomic abnormalities and potentially increased risk of arthrofibrosis. Patellar resurfacing is often not feasible because of lack of bone stock.

Not all questions are created equal: the weight of the Oxford Knee Scores questions in a multicentric validation study.

BACKGROUND: The Oxford Knee Score (OKS) has been designed for patients with knee osteoarthritis and has a widespread use. It has 12 questions, with each question having the same weight for the overall score. Some authors have observed a significant ceiling effect, especially when distinguishing slight postoperative differences. We hypothesized that each questions' weight will depend significantly on the patient's sociodemographic data and lifestyle. METHODS: In this international multicentric prospective study, we included patients attending a specialist outpatient knee clinic. Each patient filled out 3 questionnaires: (a) demographic data and data pertaining to the OKS, (b) the standard OKS, and (c) the patient gave a mark on the weight of the importance of each question, using a 5-point Likert scale (G OKS). Linear regression models were used for the analysis. RESULTS: In total 203 patients (106 female and 97 male) with a mean age of 64.5 (±12.7) years and a mean body mass index (BMI) of 29.34 (±5.45) kg/m2 were included. The most important questions for the patients were the questions for pain, washing, night pain, stability, and walking stairs with a median of 5. In the regression models, age, gender, and driving ability were the most important factors for the weight of each of the question. CONCLUSION: The questions in the OKS differ significantly in weight for each patient, based on sociodemographic data, such as age, self-use of a car, and employment. With these differences, the Oxford Knee Score might be limited as an outcome measure. Adjustment of the OKS that incorporates the demographic differences into the final score might be useful if the ceiling effect is to be mitigated. LEVEL OF EVIDENCE: Level II prospective prognostic study.