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.

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.

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.

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.

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.

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.

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.

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.

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.

Eight respectively nine out of ten patients return to sport and work after distal femoral osteotomy.

PURPOSE: Distal femoral osteotomy (DFO) is a well-accepted procedure for the treatment of femoral deformities and associated symptoms including osteoarthritis, especially in younger and physically active patients in whom knee arthroplasty is undesirable. Still, there is an apparent need for evidence on relevant patient outcomes, including return to sport (RTS) and work (RTW), to further justify the use of knee osteotomy instead of surgical alternatives. Therefore, the purpose of the present study was to investigate the extent and timing of patients' RTS and RTW after DFO. METHODS: This monocentre, retrospective cohort study included consecutive DFO patients, operated between 2012 and 2015. Out of 126 eligible patients (18-70 years, 63% female), all patients responded, and 100 patients completed the questionnaire. Median follow-up was 3.4 years (range 1.5-5.2). The predominant indication for surgery was symptomatic unicompartmental osteoarthritis and valgus or varus leg alignment caused by a femoral deformity. The primary outcome measure was the percentage of RTS and RTW. Secondary outcome measures included time to RTS/RTW, sports level and frequency, the median pre-symptomatic and postoperative Tegner activity score (1-10, higher is more active) and the postoperative Lysholm score (0-100, higher is better). RESULTS: Out of 84 patients participating in sports preoperatively, 65 patients (77%) returned to sport postoperatively. Forty-six patients (71%) returned to sports within 6 months. Postoperative participation in high-impact sports was possible though less frequent compared to preoperative participation. Out of 80 patients working preoperatively, 73 (91%) returned to work postoperatively, of whom 59 patients (77%) returned within 6 months. The median pre-symptomatic Tegner activity score [4.0 (range 0-10)] was significantly higher (p < 0.01) than the reported Tegner score at follow-up [3.0 (range 0-10)]. The mean Lysholm score at follow-up was 68 (± 22). No significant differences were found between the osteoarthritis- and non-osteoarthritis group. CONCLUSION: Eight out of ten patients return to sport and nine out of ten patients return to work after DFO. These are clinically relevant findings, because they further justify DFO as a surgical alternative to KA in young, active knee OA patients who wish to return to high activity levels. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.

The negative effect of joint line elevation after total knee arthroplasty on outcome.

PURPOSE: Total knee arthroplasty (TKA) is widely used as a treatment for knee osteoarthritis. However, still up to 20% of the patients are dissatisfied. Joint line elevation after TKA might be a contributing factor as it alters knee kinematics. The aim of this study was to investigate the effect of joint line elevation on outcome. METHODS: A systematic review of the literature was performed to select studies that reported on joint line alterations after primary or revision TKA and outcome. Studies with comparable outcome parameters were included in a correlation analysis. RESULTS: In total, 396 studies were identified, of which 27 met the inclusion criteria. 8 studies could be included in the correlation analysis. Mean joint line elevation after primary TKA was 3.0 mm and after revision TKA this was 3.6 mm. A statistically significant negative correlation was found between joint line elevation and the postoperative Knee Society Score (KSS) function score (ρ = - 0.496, p < 0.001). In a pooled analysis, the maintained joint line revision TKA group had statistically significant better postoperative KSS total scores compared to an elevated joint line group (p < 0.001). CONCLUSION: In this systematic review, a negative correlation between joint line elevation and outcome was found. Furthermore, revision TKAs with a maintained joint line have statistically significant better postoperative KSS scores compared to an elevated joint line group. To achieve optimal outcome after TKA, restoration of the joint line is one of the parameters that should be pursued and introduced elevation should not exceed 4 mm. LEVEL OF EVIDENCE: IV.

Three Out of Ten Working Patients Expect No Clinical Improvement of Their Ability to Perform Work-Related Knee-Demanding Activities After Total Knee Arthroplasty: A Multicenter Study.

Purpose Three out of ten patients do not return to work after total knee arthroplasty (TKA). Patient expectations are suggested to play a key role. What are patients' expectations regarding the ability to perform work-related knee-demanding activities 6 months after TKA compared to their preoperative status? Methods A multi-center cross-sectional study was performed among 292 working patients listed for TKA. The Work Osteoarthritis or joint-Replacement Questionnaire (WORQ, range 0-100, minimal important difference 13) was used to assess the preoperatively experienced and expected ability to perform work-related knee-demanding activities 6 months postoperatively. Differences between the preoperative and expected WORQ scores were tested and the most difficult knee-demanding work-related activities were described. Results Two hundred thirty-six working patients (81%) completed the questionnaire. Patients' expected WORQ score (Median = 75, IQR 60-86) was significantly (p < 0.01) higher than their preoperative WORQ score (Median = 44, IQR 35-56). A clinical improvement in ability to perform work-related knee-demanding activities was expected by 72% of the patients, while 28% of the patients expected no clinical improvement or even worse ability to perform work-related knee-demanding activities 6 months after TKA. Of the patients, 34% expected severe difficulty in kneeling, 30% in crouching and 17% in clambering 6 months after TKA. Conclusions Most patients have high expectations, especially regarding activities involving deep knee flexion. Remarkably, three out of ten patients expect no clinical improvement or even a worse ability to perform work-related knee-demanding activities 6 months postoperatively compared to their preoperative status. Therefore, addressing patients expectations seems useful in order to assure realistic expectations regarding work activities.

Not Physical Activity, but Patient Beliefs and Expectations are Associated With Return to Work After Total Knee Arthroplasty.

BACKGROUND: After total knee arthroplasty (TKA), 17%-60% of the patients do not or only partially return to work (RTW). Reasons for no or partial RTW remain unclear, warranting further research. Physical activity (PA) has proven beneficial effects on work participation. Therefore, we hypothesized that preoperative PA is associated with RTW after TKA. METHODS: Working TKA patients participating in an ongoing prospective cohort study were included. Preoperatively and 1 year postoperatively, patients were asked to define their work status and PA level according to the Dutch Recommendation for Health-Enhancing PA and the Fitnorm. Multivariate logistic regression analysis was performed to assess the effect of PA on RTW, taking into account established prognostic factors for RTW among TKA patients. RESULTS: Of 283 eligible patients, 266 (93%) completed the questionnaires sufficiently. Preoperatively, 141 patients (54%) performed moderate PA for ≥5 d/wk and 42 (16%) performed intense PA for ≥3 d/wk. Concerning RTW, 178 patients (67%) reported full RTW, 59 patients (22%) partial RTW, and 29 patients (11%) no RTW. Preoperative PA was not associated with RTW. Patients who reported that their knee symptoms were not or only partially work-related had lower odds of no RTW (odds ratio 0.37, 95% confidence interval 0.17-0.81). Also, for each additional week patients expected to be absent from work, the likelihood of no RTW increased (odds ratio 1.11, 95% confidence interval 1.03-1.18). CONCLUSION: No association between preoperative PA and RTW after TKA was found. Patient beliefs and preoperative expectations did influence RTW and should be addressed to further improve RTW after TKA.

Expectations of younger patients concerning activities after knee arthroplasty: are we asking the right questions?

PURPOSE: Indications for total and unicondylar knee arthroplasty (KA) have expanded to younger patients, in which Patient-Reported Outcome Measures (PROMs) often show ceiling effects. This might be due to higher expectations. Our aims were to explore expectations of younger patients concerning activities in daily life, work and leisure time after KA and to assess to what extent PROMs meet and evaluate these activities of importance. METHODS: Focus groups were performed among osteoarthritis (OA) patients <65 years awaiting KA, in which they indicated what activities they expected to perform better in daily life, work and leisure time after KA. Additionally, 28 activities of daily life, 17 of work and 27 of leisure time were depicted from seven PROMS, which were rated on importance, frequency and bother. A total score, representing motivation for surgery, was also calculated. RESULTS: Data saturation was reached after six focus groups including 37 patients. Younger OA patients expect to perform better on 16 activities after KA, including high-impact leisure time activities. From the PROMs, daily life and work activities were rated high in both importance and motivation for surgery, but for leisure time activities importance varied highly between patients. All seven PROMs score activities of importance, but no single PROM incorporates all activities rated important. CONCLUSION: Younger patients expect to perform better on many activities of daily life, work and leisure time after KA, and often at demanding levels. To measure outcomes of younger patients, we suggest using PROMs that include work and leisure time activities besides daily life activities, in which preferably scored activities can be individualized.

Outpatient unicompartmental knee arthroplasty: who is afraid of outpatient surgery?

PURPOSE: In recent years, duration of hospitalisation after knee arthroplasty has decreased and fast track and outpatient surgery protocols have been developed. Studies have shown that outpatient surgery is feasible, safe, and cost effective. However, the psychological well-being of patients undergoing outpatient surgery has never been described before. The purpose of this study was to investigate how patients experience outpatient surgery for unicompartmental knee arthroplasty (UKA), examining levels of anxiety and depression, satisfaction, and pain. It was hypothesized that the same-day discharge following UKA would not result in higher levels of anxiety and depression, compared to the standard fast-track surgery. METHODS: This case-controlled study included 20 patients undergoing UKA in an outpatient surgery setting and 20 patients undergoing the standard fast-track procedure. The Hospital Anxiety and Depression Scale (HADS, 0-42, lower is better) and numeric rating scales (NRS, 0-10) for pain and satisfaction were collected preoperatively, on the day of surgery, on the first, second, and seventh postoperative days and after 6 and 12 weeks. The Oxford Knee Score (OKS), the KOOS, EuroQoL-5D, and Net Promoter Score (NPS) were collected preoperatively and 3 months postoperatively. RESULTS: 90% of patients in the outpatient surgery group were discharged on the day of surgery. At the first postoperative day, the median HADS score was significantly lower in the outpatient surgery group compared to the fast-track group (3 vs. 8, p = 0.02), the median NRS satisfaction score was significantly higher in the outpatient surgery group (8 vs. 5, p = 0.03), and no differences existed between both groups for the NRS pain scores. At 3 month follow-up, no significant differences in improvement scores existed between both groups for the HADS, the NRS scores, and for the OKS, KOOS, EuroQoL-5D, and NPS. CONCLUSION: The results of this study emphasize the feasibility of an outpatient surgery pathway in carefully selected UKA patients. The outpatient surgery pathway is safe, and clinical outcome, including levels of anxiety and depression, satisfaction, and pain, was similar in outpatient surgery patients compared to the standard fast-track patients. LEVEL OF EVIDENCE: Case-control study, Level III.

Which patients do not return to work after total knee arthroplasty?

Total knee arthroplasty (TKA) is increasingly being performed among working patients suffering from knee osteoarthritis. Two out of ten patients do not return to work (RTW) after TKA. Little evidence is available about these patients to guide clinicians. Therefore, this study investigates patients' characteristics associated with no RTW. A multicenter retrospective cohort study was performed among working patients having undergone a primary TKA during 2005-2010. The following preoperative characteristics were assessed: age at surgery, sex, comorbidity, body mass index (BMI), preoperative sick-leave duration, patient-reported work-relatedness of knee symptoms, and physical job demands. In addition, the Knee injury and Osteoarthritis Outcome Scores (KOOS) after TKA were assessed. Backward stepwise logistic regression analyses were performed to predict no RTW. Seven hundred and sixty-four patients were approached, and 558 patients (73 %) responded. One hundred and sixty-seven met the inclusion criteria and 46 did not RTW. A preoperative sick-leave duration >2 weeks (OR 12.5, 90 % CI 5.0-31.5) was most strongly associated with no RTW. Other associations found were: female sex (OR 3.2, 90 % CI 1.3-8.2), BMI ≥ 30 (OR 2.8, 90 % CI 1.1-7.1), patient-reported work-relatedness of knee symptoms (OR 5.3, 90 % CI 2.0-14.1), and a physically knee-demanding job (OR 3.3, 90 % CI 1.2-8.9). Age and KOOS were not associated with no RTW. Especially obese female workers, with a preoperative sick-leave duration >2 weeks, who perform knee-demanding work and indicate that their knee symptoms are work-related have a high chance for no RTW after TKA. These results stress the importance of a more timely referral for work-directed care of patients at risk for no RTW after TKA.

Does Goal Attainment Scaling improve satisfaction regarding performance of activities of younger knee arthroplasty patients? Study protocol of the randomized controlled ACTION trial.

BACKGROUND: Knee arthroplasty is being increasingly performed, and also more often in a younger patient population (<65 years of age). Up to 20 % of patients remain dissatisfied after knee arthroplasty, despite the apparent technical success of the operation. Recent studies suggest that the fulfilment of patients' expectations plays an important role in achieving satisfaction. Thus, addressing preoperative expectations more explicitly might improve patient satisfaction. The primary aim of the present study is to investigate the effect of a multidisciplinary, goal attained and individualized rehabilitation on satisfaction of activities of younger patients (<65 years) after knee arthroplasty. METHODS/DESIGN: A single-centre randomized controlled trial will be conducted. In total, 120 patients (<65 years of age) with knee osteoarthritis who will undergo knee arthroplasty, will be randomly allocated to either goal attainment scaling rehabilitation or usual care rehabilitation. Goal attainment scaling rehabilitation includes drafting individually set rehabilitation goals preoperatively and measuring progress of rehabilitation on a six-point scale (-3 to +2). The primary outcome is patient satisfaction concerning activities in daily life, work and leisure time, including sports. Secondary outcome measures include KOOS, OKS, SQUASH and WORQ questionnaires and activity objectively measured with the Activ8® activity monitor. DISCUSSION: The findings of this study will help to elucidate whether goal attainment scaling is an effective rehabilitation method for achieving higher levels of patient satisfaction, with a focus on activities, in younger patients after knee arthroplasty. TRIAL REGISTRATION: This trial is since June 15(th) 2015 registered at the Dutch Trial Register: NTR5251 .

Medial femoral condyle fracture as an intraoperative complication of Oxford unicompartmental knee replacement.

Oxford unicompartmental knee replacement (OUKR) is associated with a low perioperative complication rate. This case report describes a periprosthetic fracture of the medial femoral condyle that occurred during an OUKR. The patient was treated with a non-weight-bearing long leg cast for 6 weeks. Afterwards, the fracture had healed, and 3 months postoperatively, there was a full range of motion. Factors leading to this complication could be the impaction force or direction, or a diminished load resistance of the distal femur. Minimally displaced coronal periprosthetic fractures after OUKR can be managed conservatively without residual functional impairment. LEVEL OF EVIDENCE: Case report, Level IV.

Effect of rotational alignment on outcome of total knee arthroplasty.

BACKGROUND AND PURPOSE: Poor outcomes have been linked to errors in rotational alignment of total knee arthroplasty components. The aims of this study were to determine the correlation between rotational alignment and outcome, to review the success of revision for malrotated total knee arthroplasty, and to determine whether evidence-based guidelines for malrotated total knee arthroplasty can be proposed. PATIENTS AND METHODS: We conducted a systematic review including all studies reporting on both rotational alignment and functional outcome. Comparable studies were used in a correlation analysis and results of revision were analyzed separately. RESULTS: 846 studies were identified, 25 of which met the inclusion criteria. From this selection, 11 studies could be included in the correlation analysis. A medium positive correlation (ρ = 0.44, 95% CI: 0.27-0.59) and a large positive correlation (ρ = 0.68, 95% CI: 0.64-0.73) were found between external rotation of the tibial component and the femoral component, respectively, and the Knee Society score. Revision for malrotation gave positive results in all 6 studies in this field. INTERPRETATION: Medium and large positive correlations were found between tibial and femoral component rotational alignment on the one hand and better functional outcome on the other. Revision of malrotated total knee arthroplasty may be successful. However, a clear cutoff point for revision for malrotated total knee arthroplasty components could not be identified.

Early experience with the Vanguard complete total knee system: 2-7 years of follow-up and risk factors for revision.

A cross-sectional study in two hospitals was performed on 807 patients with a primary Vanguard (Biomet) total knee Arthroplasty (TKA). The research questions addressed were (1) what are the two- and six year survival rates of the Vanguard, (2) what are the clinical outcome scores, (3) what are the findings at revision and (4) what are predictors for revision? The mean age at time of surgery was 67.0 (SD 10.0). The mean follow-up was 3.6 years (95% CI 3.56-3.73). At two years the survival was 97.2% for all-reasons (767 patients remaining) and 99%, for prosthesis-related-reasons (777 remaining). At six years this was 96.5% (40 remaining) and 98.6% (41 remaining). The mean clinical results (84% response on KOOS, Oxford and NRS) were good. A previous osteotomy was a risk factor for revision (hazard ratio 5.1, P=0.001). This early experience with the Vanguard shows a good survival with no adverse outcomes related to the implant and therefore further use of the implant is justified.