Unicompartmental knee arthroplasty questionnaire (UniQ-study): Unknown is unloved.

BACKGROUND: Almost 50% of the patients requiring knee replacement are suitable for medial unicompartmental knee arthroplasty (UKA). However, national registries have shown a use far below 50%. AIM: The aim of this study was to identify the factors that could influence the use of UKA. METHODS: A questionnaire was conducted among practicing knee surgeons of the Dutch Orthopedic Association. The questionnaire was classified into three domains: surgeon, patient selection, and professional opinion. Associations between the domains and UKA volume and contra-indications were tested using Pearson's chi-square tests. RESULTS: Of the 113 included respondents, 40% had no hands-on exposure during residency. Frequently reported contra-indications were obesity (68%), lateral osteophytes (21%), chondrocalcinosis (20%), and age (20%). Medial partial thickness lesions were considered a contra-indication by 49% and lateral joint space narrowing by 61% of the respondents. Respondents perceived UKA to outperform total knee arthroplasty regarding all outcomes, except survival (1.8% versus 42%). The reported barriers for UKA use were insufficient experience (20%), high revision rates (20%), and low hospital volume (16%), whereas 60% did not experience any at all. Hands-on UKA exposure during residency was associated with an increased use of correct indications. Furthermore, the use of correct indications was associated with an increased UKA volume. CONCLUSION: We showed a low UKA exposure during residency and considerable variations in contra-indications. These factors may contribute to an underuse of UKA. Improved UKA training could lead to increased experience and better patient selection among surgeons and consequently a higher use of medial UKA.

Valgus stress radiographs have a minor additional value in detecting lateral cartilage wear when selecting patients for medial partial knee replacement.

INTRODUCTION: A valgus stress radiograph, in addition to the weight-bearing fixed flexion posteroanterior radiograph (e.g., Rosenberg), is deemed useful to assess lateral cartilage wear by measuring lateral joint space width (JSW) in patients with medial knee osteoarthritis. This study aimed to assess: (1) the difference in measured lateral JSW between the Rosenberg and the valgus stress radiograph, and (2) the ability of the valgus stress radiograph to detect lateral cartilage wear (indicated by joint space narrowing) in patients where the Rosenberg radiograph showed full thickness cartilage (i.e., the additional value). MATERIALS AND METHODS: The Rosenberg and valgus stress radiographs, obtained between January 1st 2018 and December 31st 2018, of 137 patients with medial knee osteoarthritis prior to total or partial knee replacement were retrospectively collected. The lateral JSW was measured at its midpoint (midJSW) and minimum (minJSW). The differences were tested with a paired-sample t test. The valgus stress radiograph was considered to have an additional value if: (1) JSW ≥ 5 mm on the Rosenberg radiograph, (2) JSW < 5 mm on valgus stress radiograph, and (3) > 2 mm less JSW on the valgus stress than on the Rosenberg radiograph. RESULTS: The mean differences in lateral JSW between the Rosenberg and valgus stress radiographs were 0.53 mm (SD = 1.0 mm, p < 0.001) for midJSW and 0.66 mm (SD = 1.1 mm, p < 0.001) for minJSW with both values being lower on the valgus stress radiograph. The valgus stress radiograph was of additional value in 4-6% of the patients. CONCLUSIONS: Although the valgus stress radiograph shows more lateral JSW narrowing compared to Rosenberg radiograph, it only has an additional value in 1 out of 17-25 patients with medial osteoarthritis. We, therefore, recommend a Rosenberg radiograph as routine radiographic assessment and only use an additional valgus stress radiograph in case of discrepancy between clinical and radiological findings.

No difference in the use of revision components and rerevision rate in conversion to total knee replacement following Oxford Partial Knee Microplasty Instrumentation: a registry study of 529 conversions.

BACKGROUND AND PURPOSE: Microplasty Instrumentation was introduced to improve Oxford Mobile Partial Knee placement and preserve tibial bone in partial knee replacement (PKR). This might therefore reduce revision complexity. We aimed to assess the difference in use of revision total knee replacement (TKR) tibial components in failed Microplasty versus non-Microplasty instrumented PKRs. PATIENTS AND METHODS: Data on 529 conversions to TKR (156 Microplasty instrumented and 373 non-Microplasty instrumented PKRs) from the Dutch Arthroplasty Register (LROI) between 2007 and 2019 was used. The primary outcome was the difference in use of revision TKR tibial components during conversion to TKR, which was calculated with a univariable logistic regression analysis. The secondary outcomes were the 3-year re-revision rate and hazard ratios calculated with Kaplan-Meier and Cox regression analyses. RESULTS: Revision TKR tibial components were used in 29% of the conversions to TKR after failed Microplasty instrumented PKRs and in 24% after failed non-Microplasty instrumented PKRs with an odds ratio of 1.3 (CI 0.86-2.0). The 3-year re-revision rates were 8.4% (CI 4.1-17) after conversion to TKR for failed Microplasty and 11% (CI 7.8-15) for failed non-Microplasty instrumented PKRs with a hazard ratio of 0.77 (CI 0.36-1.7). CONCLUSION: There was no difference in use of revision tibial components for conversion to TKR or in re-revision rate after failed Microplasty versus non-Microplasty instrumented PKRs nor in the 3-year revision rate.

Joint distraction using a purpose-built device for knee osteoarthritis: a prospective 2-year follow-up.

OBJECTIVE: Knee distraction treatment for end-stage osteoarthritis successfully postpones arthroplasty for years. Studies performed thus far used general intended use, patient-personalised or custom-made devices. In this study, for the first time, a device specifically designed for knee distraction is evaluated. DESIGN: 65 patients (≤65 years) with end-stage knee osteoarthritis indicated for arthroplasty received knee distraction. Before, 1-year and 2-year post-treatment, questionnaires were filled out and knee radiographs made. Adverse events and self-reported pain medication were registered. RESULTS: Forty-nine patients completed 2-year follow-up: one patient did not complete treatment, three patients received arthroplasty in the first and four patients in the second year follow-up. Eight patients were lost to follow-up in the second year. The total Western Ontario and McMaster Universities Osteoarthritis Index score showed a clinically relevant improvement at 1 and 2 years (+26 and +24 points), as did all subscales (all p<0.001). The minimum radiographic joint space width improved over 1 (+0.5 mm; p<0.001) and 2 (+0.4 mm; p=0.015) years, as did the physical Short-Form 36 (+10 points; p<0.001). The most common adverse event was pin tract infection, experienced by 66% of patients, in 88% successfully treated with oral antibiotics. In two cases, hospitalisation and/or intravenous antibiotics were needed. Eight patients experienced device-related complications. None of the complications influenced 2-year outcomes. Before treatment, 42% of patients used pain medication, which had nearly been halved 1 (23%; p=0.02) and 2 years (29%; p=0.27) post-treatment. CONCLUSIONS: Patients treated with a general applicable, for knee distraction purpose-built device showed, despite adverse events, significant clinical and structural improvement over 2 years. TRIAL REGISTRATION NUMBER: NL7986.

Only Low Patients' Expectations Are Prognostic for Dissatisfaction With Performing Work-Related Knee-Straining Activities After Total Knee Arthroplasty: A Prospective Multicenter Cohort Study.

OBJECTIVE: To investigate whether preoperative expectations regarding performing work-related knee-straining activities were associated with being dissatisfied 6 months after total knee arthroplasty (TKA) among working patients, and, to identify prognostic factors for being dissatisfied with performing these work-related knee-straining activities. DESIGN: Multicenter prospective cohort study. SETTING: Orthopedic surgery departments of 7 hospitals in the Netherlands. PARTICIPANTS: A consecutive sample of 175 working patients who were on the waiting list for TKA (median age 59 years, 53% women) and intended to return to work (N=175). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE(S): Dissatisfaction with performing work-related knee-straining activities 6 months postoperative was measured using the Work Osteoarthritis or joint-Replacement Questionnaire (score range 0-100). The clinically relevant cut-off points for being satisfied and dissatisfied were ≥71 and ≤50, respectively. RESULTS: Thirty-three patients (19%) were dissatisfied with performing work-related knee-straining activities 6 months after TKA. Patients who expected to be dissatisfied preoperative had a 5.1 times higher odds (95% CI 1.7-15.5) of being dissatisfied 6 months postoperatively compared with patients who expected to be satisfied preoperative. Regression analyses revealed that only patients' expectations were prognostic for being dissatisfied 6 months postoperatively rather than age, pain level, or having a knee-straining job. CONCLUSIONS: Two in 10 working patients are dissatisfied with performing work-related knee-straining activities 6 months after TKA. Only preoperative patients' expectations appeared prognostic. Therefore, we should better prepare working patients with low expectations by managing their preoperative expectations and improving their performance of work-related knee-straining activities in rehabilitation.

Reduced 5-Year Risk for Revision of the Oxford UKA Using New Instrumentation versus Conventional Instrumentation: A Registry Study of 12,867 UKAs.

Microplasty instrumentation was introduced for a more consistent surgical implantation technique, especially component alignment and tibial resection level, of the Oxford medial unicompartmental knee arthroplasty (UKA) and thereby aims to improve UKA survival. This study aimed to assess the 5-year risk for revision and reasons for revision of the Oxford medial UKA using the new instrumentation (Microplasty) with its predecessor, that is, conventional instrumentation (Phase 3). Data of all medial UKAs from the Dutch Arthroplasty Register (Landelijke Registratie Orthopedische Implantaten) between 2007 and 2019 were collected. Type of instrumentation was divided into new (Microplasty) and conventional instrumentation. Kaplan-Meier analysis was performed to calculate 5-year cumulative revision percentage with any reason for revision as end point. A multivariable Cox regression with outcome revision of UKA adjusted for age, gender, American Society of Anesthesiologists score, surgical history, and type of fixation was performed. Additionally, reasons for revision at 3-year were assessed and tested through Fisher's exact tests. A total of 12,867 Oxford medial UKAs, 8,170 using new and 4,697 using conventional instrumentation, were included. The 5-year revision percentage was 9.2% (95% confidence interval [CI]: 8.4-10.1%) for UKAs using the conventional and 6.1% (95% CI: 5.4-6.7%) for new instrumentation. The adjusted hazard ratio for revision at 5-year follow-up was 0.74 (95% CI: 0.63-0.87) in favor of UKAs using the new instrumentation. Malalignment was more frequently registered as reason for revision in UKAs using the conventional compared with the new instrumentation (16% versus 7.5%; p = 0.001). Our results show a reduced 5-year risk for revision of the medial Oxford UKAs using the new compared with the conventional instrumentation. This might be the result of a lower revision rate for malalignment in UKAs using the new instrumentation.

Return to Sport and Work after Randomization for Knee Distraction versus High Tibial Osteotomy: Is There a Difference?

Knee joint distraction (KJD) is a novel technique for relatively young knee osteoarthritis (OA) patients. With KJD, an external distraction device creates temporary total absence of contact between cartilage surfaces, which results in pain relief and possibly limits the progression of knee OA. Recently, KJD showed similar clinical outcomes compared with high tibial osteotomy (HTO). Yet, no comparative data exist regarding return to sport (RTS) and return to work (RTW) after KJD. Therefore, our aim was to compare RTS and RTW between KJD and HTO. We performed a cross-sectional follow-up study in patients <65 years who previously participated in a randomized controlled trial comparing KJD and HTO. Out of 62 eligible patients, 55 patients responded and 51 completed the questionnaire (16 KJDs and 35 HTOs) at 5-year follow-up. The primary outcome measures were the percentages of RTS and RTW. Secondary outcome measures included time to RTS/RTW, and pre- and postoperative Tegner's (higher is more active), and Work Osteoarthritis or Joint-Replacement Questionnaire (WORQ) scores (higher is better work ability). Patients' baseline characteristics did not differ. Total 1 year after KJD, 79% returned to sport versus 80% after HTO (not significant [n.s.]). RTS <6 months was 73 and 75%, respectively (n.s.). RTW 1 year after KJD was 94 versus 97% after HTO (n.s.), and 91 versus 87% <6 months (n.s.). The median Tegner's score decreased from 5.0 to 3.5 after KJD, and from 5.0 to 3.0 after HTO (n.s.). The mean WORQ score improvement was higher after HTO (16 ± 16) than after KJD (6 ± 13; p = 0.04). Thus, no differences were found for sport and work participation between KJD and HTO in our small, though first ever, cohort. Overall, these findings may support further investigation into KJD as a possible joint-preserving option for challenging "young" knee OA patients. The level of evidence is III.

Patient-specific instruments do not show advantage over conventional instruments in unicompartmental knee arthroplasty at 2 year follow-up: a prospective, two-centre, randomised, double-blind, controlled trial.

PURPOSE: The aim of this two-centre RCT was to compare pre- and post-operative radiological, clinical and functional outcomes between patient-specific instrumentation (PSI) and conventional instrumented (CI) unicompartmental knee arthroplasty (UKA). It was hypothesised that both alignment methods would have comparable post-operative radiological, clinical and functional outcomes. METHODS: One hundred and twenty patients were included, and randomly allocated to the PSI or the CI group. Outcome measures were peri-operative outcomes (operation time, length of hospital stay and intra-operative changes of implant size) and post-operative radiological outcomes including the alignment of the tibial and femoral component in the sagittal and frontal plane and the hip-knee-ankle-axis (HKA-axis), rate of adverse events (AEs) and patient-reported outcome measures (PROMs) pre-operatively and at 3, 12 and 24 months post-operatively. RESULTS: There was a statistically significant difference (p < 0.05) in alignment of the femoral component in the frontal plane in favour of the CI method. No statistically significant differences were found for the peri-operative data or in the functional outcome at 2-year follow-up. In the PSI group, the approved implant size of the femoral component was correct in 98.2% of the cases and the tibial component was correct in 60.7% of the cases. There was a comparable rate of AEs: 5.1% in the CI and 5.4% in the PSI group. CONCLUSION: The PSI method did not show an advantage over CI in regard of positioning of the components, nor did it show an improvement in clinical or functional outcome. We conclude that the possible advantages of PSI do not outweigh the costs of the MRI scan and the manufacturing of the PSI. LEVEL OF EVIDENCE: Randomised controlled trial, level I.

A structured evaluation of the symptomatic medial Oxford unicompartmental knee arthroplasty (UKA).

Unicompartmental knee arthroplasty (UKA) has several advantages over total knee arthroplasty; however, in many reports, the risk of revision remains higher after UKA.Many reasons for failure of UKA exist.Successful treatment starts with accurate assessment of the symptomatic UKA as a specific mode of failure requires a specific solution.A structured and comprehensive evaluation aids assessment of the symptomatic UKA.This review provides an overview of the causes for a symptomatic medial UKA, its risk factors, diagnostic modalities that can be used, and briefly discusses treatment options. Cite this article: EFORT Open Rev 2021;6:850-860. DOI: 10.1302/2058-5241.6.200105.

Knee Joint Distraction as Treatment for Osteoarthritis Results in Clinical and Structural Benefit: A Systematic Review and Meta-Analysis of the Limited Number of Studies and Patients Available.

OBJECTIVE: Knee joint distraction (KJD) is a joint-preserving osteoarthritis treatment that may postpone a total knee arthroplasty (TKA) in younger patients. This systematic review and meta-analysis evaluates short- and long-term clinical benefit and tissue structure changes after KJD. DESIGN: MEDLINE, EMBASE, and Web of Science were searched for eligible clinical studies evaluating at least one of the primary parameters: WOMAC, VAS-pain, KOOS, EQ5D, radiographic joint space width or MRI cartilage thickness after KJD. Random effects models were applied on all outcome parameters and outcomes were compared with control groups found in the included studies. RESULTS: Eleven articles reporting on 7 different KJD cohorts with in total 127 patients and 5 control groups with multiple follow-up moments were included, of which 2 were randomized controlled trials. Significant improvements in all primary parameters were found and benefit lasted up to at least 9 years. Overall, outcomes were comparable with control groups, including high tibial osteotomy, although TKA showed better clinical response. CONCLUSIONS: Current, still limited, evidence shows KJD causes clear benefit in clinical and structural parameters, both short- and long-term. Longer follow-up with more patients is necessary, to validate outcome and to potentially improve patient selection for this intensive treatment. Thus far, for younger knee osteoarthritis patients, KJD may be an option to consider.

Non-surgical treatment before hip and knee arthroplasty remains underutilized with low satisfaction regarding performance of work, sports, and leisure activities.

Background and purpose - Guidelines for managing hip and knee osteoarthritis (OA) advise extensive non-surgical treatment prior to surgery. We evaluated what percentage of hip and knee OA patients received non-surgical treatment prior to arthroplasty, and assessed patient satisfaction regarding alleviation of symptoms and performance of activities. Patients and methods - A multi-center cross-sectional study was performed in 2018 among 186 patients who were listed for hip or knee arthroplasty or had undergone surgery within the previous 6 months in the Netherlands. Questions concerned non-surgical treatments received according to the Stepped Care Strategy and were compared with utilization in 2013. Additionally, satisfaction with treatment effects for pain, swelling, stiffness, and activities of daily life, work, and sports/leisure was questioned. Results - The questionnaire was completed by 175 patients, age 66 years (range 38-84), 57% female, BMI 29 (IQR 25-33). Step 1 treatments, such as acetaminophen and lifestyle advice, were received by 79% and 60% of patients. Step 2 treatments, like exercise-based therapy and diet therapy, were received by 66% and 19%. Step 3-intra-articular injection-was received by 47%. Non-surgical treatment utilization was lower than in 2013. Nearly all treatments showed more satisfied patients regarding pain relief and fewer regarding activities of work/sports/leisure. Hip and knee OA patients were mostly satisfied with NSAIDs for all outcomes, while exercise-based therapy was rated second best. Interpretation - Despite international guideline recommendations, non-surgical treatment for hip and knee OA remains underutilized in the Netherlands. Of the patients referred for arthroplasty, more were satisfied with the effect of non-surgical treatment on pain than on work/sports/leisure participation.

Goal Attainment Scaling Rehabilitation Improves Satisfaction with Work Activities for Younger Working Patients After Knee Arthroplasty: Results from the Randomized Controlled ACTION Trial.

BACKGROUND: Knee arthroplasty (KA) is increasingly performed in relatively young, active patients. This heterogeneous patient population often has high expectations, including work resumption and performance of knee-demanding leisure-time activities. Goal attainment scaling (GAS) may personalize rehabilitation by using patient-specific, activity-oriented rehabilitation goals. Since unmet expectations are a leading cause of dissatisfaction after KA, personalized rehabilitation may improve patient satisfaction. We hypothesized that, compared with standard rehabilitation, GAS-based rehabilitation would result in younger, active patients having higher satisfaction regarding activities after KA. METHODS: We performed a single-center randomized controlled trial. Eligible patients were <65 years of age, working outside the home, and scheduled to undergo unicompartmental or total KA. The required sample size was 120 patients. Using GAS, patients developed personal activity goals with a physiotherapist preoperatively. These goals were used to monitor patients' goal attainment and provide goal-specific feedback during postoperative outpatient rehabilitation. Standard rehabilitation consisted of regular outpatient physiotherapy visits. The primary outcome measures were visual analogue scale (VAS) scores (scale of 0 to 100) for satisfaction regarding activities of daily living and work and leisure-time activities 1 year postoperatively, which were analyzed using generalized estimating equation models. RESULTS: Patient satisfaction with work activities was significantly higher in the GAS group (ß = 10.7 points, 98% confidence interval [CI] = 2.0 to 19.4 points) than in the control group. Patient satisfaction with activities of daily living and leisure-time activities did not differ between groups. We found no differences in VAS satisfaction scores between unicompartmental KA and total KA. CONCLUSIONS: Personalized, goal-specific rehabilitation using GAS resulted in higher patient satisfaction with work activities, compared with standard rehabilitation, 1 year after KA. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Higher risk of revision for partial knee replacements in low absolute volume hospitals: data from 18,134 partial knee replacements in the Dutch Arthroplasty Register.

Background and purpose - Partial knee replacement (PKR) survival rates vary a great deal among registries and cohort studies. These discrepancies can largely be attributed to inappropriate indications of the PKR and low thresholds for revision, but also to the PKR volume. This study used Dutch Arthroplasty Register data to analyze whether absolute PKR or proportional PKR hospital volume is associated with the risk of revision.Patients and methods - 18,134 PKRs were identified in the Dutch Arthroplasty Register from 2007 to 2016. For each year, hospitals were divided into 4 groups based on the quartiles for the absolute volume (< 22, 22-36, 36-58 and > 58 PKRs per year) and the proportional volume (< 8.5, 8.6-14.2, 14.3-25.8 and > 25.8% PKRs). Kaplan-Meier survival analysis was performed to determine survival rates. A multivariable Cox regression adjusted for age category, sex, ASA score, year of surgery, diagnosis, unicondylar side, and type of hospital was used to estimate hazard ratios (HR) for revision.Results and interpretation - Proportional PKR volume did not, but absolute PKR volume did influence the risk of revision. The adjusted HR for hospitals with an absolute volume of 22-36 PKRs per year was 1.04 (95% CI 0.91-1.20), 0.96 (CI 0.83-1.10) for the hospitals with 36-58 PKRs, and 0.74 (CI 0.62-0.89) for hospitals with more than 58 PKRs compared with hospitals that had fewer than 22 PKRs per year. So, patients treated with a PKR in a high absolute volume hospital have a lower risk of revision compared with those treated in a low absolute volume hospital.

A Comprehensive Evaluation of Lateral Unicompartmental Knee Arthroplasty Short to Mid-Term Survivorship, and the Effect of Patient and Implant Characteristics: An Analysis of Data From the Dutch Arthroplasty Register.

BACKGROUND: The rarity of lateral unicompartmental knee arthroplasty (UKA) results in a lack of large cohort studies and understanding. The aim of this study is to comprehensively evaluate survivorship of lateral UKA with registry data and compare this to medial UKA. METHODS: Lateral (n = 537) and medial UKAs (n = 19,295) in 2007-2017 were selected from the Dutch Arthroplasty Register. Survival analyses were performed with revision for any reason as primary endpoint. Adjustments were made for patient and implant characteristics. Stratified analyses according to patient and implant characteristics were performed. Reasons and type of revision were grouped according to laterality and bearing design. RESULTS: The 5-year revision rate was 12.9% for lateral UKA and 9.3% for medial UKA. Multivariable regression analyses showed no significant increased risk for revision for lateral UKA (hazard ratio 0.87, 95% confidence interval 0.66-1.15). Stratified analyses showed that the effect of patient characteristics on revision was comparable between lateral and medial UKA; however, the use of mobile-bearing design for lateral UKA was associated with increased revision rate. Progression of osteoarthritis was the main reason for revision on both sides accompanied by tibia component loosening for medial UKA. Reasons and type of revision varied depending on bearing design. CONCLUSION: Similar survivorship of lateral and medial UKA was reported. Specifically, there is a notable risk for revision when using mobile-bearing designs for lateral UKA. Failure modes and type of revision depends on laterality and bearing design. These findings emphasize that surgical challenges related to anatomy and kinematics of the lateral and medial knee compartment need to be considered.

Patients return to work sooner after unicompartmental knee arthroplasty than after total knee arthroplasty.

PURPOSE: It is not yet known if unicompartmental knee arthroplasty (UKA) patients are more likely to return to work sooner or have improved ability to work (i.e., workability) than total knee arthroplasty (TKA) patients. The following questions were addressed: patients were assessed to determine: (1) whether they returned to work sooner following UKA compared to TKA; (2) whether UKA patients had better WORQ function scores compared to TKA patients; and (3) if UKA patients have higher workability scores and greater satisfaction regarding workability than TKA patients. METHODS: A multicenter retrospective cohort study was performed that included patients at least 2 years after having undergone either UKA or TKA surgery and on the condition that patients had been in work in the 2 years prior to surgery. Time period between stopping work and returning to work was assessed; the WORQ scores (0 = worst-100 = best) and the Work Ability Index (WAI = 0-10) and reported satisfaction with work ability. RESULTS: UKA patients (n = 157, median 60 years, 51% male) were compared to TKA patients (n = 167, median 60 years, 49% male) (n.s.). Of the 157 UKA patients, 115 (73%) returned to work within 2 years compared to 121 (72%) of TKA patients (n.s.). More UKA patients return to work within 3 months (73% versus 48%) (p < 0.01). WORQ scores improved similarly in both groups. The WAI was also comparable between the groups. Dissatisfaction with workability was comparable (UKA 15% versus TKA 18% (n.s.). CONCLUSION: TKA and UKA patients have similar WORQ, WAI, and satisfaction scores. However, in this study population, UKA patients to return to work after surgery significantly sooner than TKA patients, which improves their quality of life and allows them to participate actively in society. This information can help health care providers and patients weigh-up the pros and cons and choose the best treatment and timing for patients in the working population. LEVEL OF EVIDENCE: III.

Higher Function Scores and Satisfaction in Patients with Anteromedial Osteoarthritis Compared with Other Wear Patterns of the Knee: 2 Years after Both Total and Unicondylar Knee Arthroplasties.

Anteromedial osteoarthritis (AMOA) is a common wear pattern in primary osteoarthritic knees. In patients with bone-on-bone disease, the most appropriate surgical intervention is still a matter of debate. Knee arthroplasty is a well-accepted treatment to relieve symptoms and regain function. Unfortunately, satisfaction is limited, especially related to activities. A cross-sectional study was performed among patients treated with total knee arthroplasty (TKA) and unicondylar arthroplasty (UKA) to determine if the osteoarthritis wear pattern or type of prosthesis affects knee-specific function scores and satisfaction related to activities. All UKA patients (N = 100) were treated for AMOA. Based on radiological assessment of the wear pattern, TKA patients were divided into two groups: TKA for AMOA (N = 68) and true TKA (N = 99). The Knee injury and Osteoarthritis Outcomes Score (KOOS), new Knee Society score (KSS), anterior knee pain scale, visual analog scales (VASs) for satisfaction about activities, and net promoter score were collected. After 2 years' follow-up, the anterior knee pain scale and VAS satisfaction showed significantly better scores for patients treated with TKA for AMOA compared with the true TKA group. Also in the KOOS subscales, some differences were seen in favor of the TKA for AMOA group. The new KSS was not in favor of a specific wear pattern, but patients with AMOA treated with UKA performed better on the symptoms subscale compared with patients treated with TKA. In conclusion, patients treated with TKA for AMOA showed better knee-specific function scores and satisfaction scores compared with patients treated with TKA for other wear patterns, and only slight differences were found between both the AMOA groups (TKA for AMOA and UKA). Thus, the radiologic assessment of wear patterns might be useful to take into account the shared decision-making process, when discussing expectations, timing, and outcomes with knee osteoarthritis patients considering knee arthroplasty. When AMOA is present, it might be beneficial to choose UKA over TKA.

Does Activity-Based Rehabilitation With Goal Attainment Scaling Increase Physical Activity Among Younger Knee Arthroplasty Patients? Results From the Randomized Controlled ACTION Trial.

BACKGROUND: Especially in younger knee osteoarthritis patients, the ability to perform physical activity (PA) after knee arthroplasty (KA) is of paramount importance, given many patients' wish to return to work and perform demanding leisure time activities. Goal Attainment Scaling (GAS) rehabilitation after KA may improve PA because it uses individualized activity goals. Therefore, our aim was to objectively quantify PA changes after KA and to compare GAS-based rehabilitation to standard rehabilitation. METHODS: Data were obtained from the randomized controlled ACTION trial, which compares standard rehabilitation with GAS-based rehabilitation after total and unicompartmental KA in patients <65 years of age. At 2 time points, preoperatively and 6 months postoperatively, 120 KA patients wore a validated 3-dimensional accelerometer for 1 consecutive week. Data were classified as sedentary (lying, sitting), standing, and active (walking, cycling, running). Repeated measures analysis of variance was used to compare PA changes over time. RESULTS: Complete data were obtained for 97 patients (58% female), with a mean age of 58 years (±4.8). For the total group, we observed a significant increase in PA of 9 minutes (±37) per day (P = .01) and significant decrease in sedentary time of 20 minutes (±79) per day (P = .02). There was no difference in standing time (P = .11). There was no difference between the control group and the intervention group regarding changes in PA, nor between the total KA group and the unicompartmental KA group. CONCLUSION: We found a small but significant increase in overall PA after KA, but no difference between GAS-based rehabilitation and standard rehabilitation. Likely, enhanced multidisciplinary perioperative strategies are needed to further improve PA after KA.

Prognostic Factors for Return to Sport After High Tibial Osteotomy: A Directed Acyclic Graph Approach.

BACKGROUND: High tibial osteotomy (HTO) is increasingly used in young and physically active patients with knee osteoarthritis. These patients have high expectations, including return to sport (RTS). By retaining native knee structures, a return to highly knee-demanding activities seems possible. However, evidence on patient-related outcomes, including RTS, is sparse. Also, time to RTS has never been described. Furthermore, prognostic factors for RTS after HTO have never been investigated. These data may further justify HTO as a surgical alternative to knee arthroplasty. PURPOSE: To investigate the extent and timing of RTS after HTO in the largest cohort investigated for RTS to date and to identify prognostic factors for successful RTS. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Consecutive patients with HTO, operated on between 2012 and 2015, received a questionnaire. First, pre- and postoperative sports participation questions were asked. Also, time to RTS, sports level and frequency, impact level, the presymptomatic and postoperative Tegner activity score (1-10; higher is more active), and the postoperative Lysholm score (0-100; higher is better) were collected. Finally, prognostic factors for RTS were analyzed using a logistic regression model. Covariates were selected based on univariate analysis and a directed acyclic graph. RESULTS: We included 340 eligible patients of whom 294 sufficiently completed the questionnaire. The mean follow-up was 3.7 years (± 1.0 years). Out of 256 patients participating in sports preoperatively, 210 patients (82%) returned to sport postoperatively, of whom 158 (75%) returned within 6 months. We observed a shift to participation in lower-impact activities, although 44% of reported sports activities at final follow-up were intermediate- or high-impact sports. The median Tegner score decreased from 5.0 (interquartile range [IQR], 4.0-6.0) presymptomatically to 4.0 (IQR, 3.0-4.0) at follow-up (P < .001). The mean Lysholm score at follow-up was 68 (SD, ± 22). No significant differences were found between patients with varus or valgus osteoarthritis. The strongest prognostic factor for RTS was continued sports participation in the year before surgery (odds ratio, 2.81; 95% CI, 1.37-5.76). CONCLUSION: More than 8 of 10 patients returned to sport after HTO. Continued preoperative sports participation was associated with a successful RTS. Future studies need to identify additional prognostic factors.

More Severe Preoperative Kellgren-Lawrence Grades of Knee Osteoarthritis were Partially Associated with Better Postoperative Patient-Reported Outcomes in TKA Patients.

Total knee arthroplasty (TKA) is a successful procedure, although up to 20% of patients remain dissatisfied. Preoperative identification of appropriate TKA candidates is essential for improving satisfaction. This study investigated if preoperative radiographic severity was associated with postoperative pain, function, and quality of life after TKA. We performed a cross-sectional cohort study including 327 TKA patients. Radiographic severity was determined by two independent radiologists using the Kellgren and Lawrence (KL) score. The Knee Injury and Osteoarthritis Outcome Score (KOOS), the New Knee Society Score (New KSS), and Anterior Knee Pain Score (AKPS) were collected. We evaluated the association between KL grade and patient-reported outcome measures (PROMs) with the use of regression analysis techniques. Out of 228 responders, 195 patients completed the questionnaire sufficiently. Forty-seven patients were classified as KL grades 1 to 2, and 144 patients were classified as KL grades 3 to 4. The inter-observer reliability between both radiologists was substantial (Ï° = 0.67). After adjusting for age, sex, and body mass index (BMI), the New KSS subscales symptoms and expectations, and the KOOS subscale quality of life were significantly higher in the KL grades 3 to 4 group. However, neither the remaining KOOS subscales and AKPS nor KOOS change scores differed between both groups. Thus, more severe osteoarthritis (OA) resulted in better outcomes after TKA, although this association was not observed for all PROMs. The use of new PROMs, such as the New KSS, could be more reliable because of lower ceiling effects than the KOOS. Investigating the value of additional methods to assess radiographic severity (such as semi-flexed knee radiographs and MRI) is imperative to reliably identify knee OA.