Aims. To identify the responsiveness, minimal clinically important difference (MCID), minimal clinical important change (MIC), and patient-acceptable symptom state (PASS) thresholds in the 36-item Short Form Health Survey questionnaire (SF-36) (v2) for each of the eight dimensions and the total score following total knee arthroplasty (TKA). Methods. There were 3,321 patients undergoing primary TKA with preoperative and one-year postoperative SF-36 scores. At one-year patients were asked how satisfied they were and “How much did the knee arthroplasty surgery improve the quality of your life?”, which was graded as: great, moderate, little (n = 277), none (n = 98), or worse. Results. Physical function, role limitations due to physical problems (‘role physical’), bodily pain, and the total score SF-36 scores demonstrated the greatest effect sizes (> 0.9). The MCID for each of SF-36 dimensions ranged from 1.7 for role emotional to 6.4 for bodily pain. The MICs for a cohort of patients ranged from -1.0 for general health to 11.1 for bodily pain. The MICs for an individual patient were marginally greater (one to two points) compared to those for a cohort, and ranging from 0.0 for general and mental health to 13.5 for physical function. The lowest PASS score threshold was associated with physical function (> 34 points) whereas the greatest threshold (> 69 points) was associated with mental health. Conclusion. The SF-36 is a responsive tool, and the estimates for MCID, MIC, and PASS thresholds that can be used to power studies, assess whether there has been a meaningful change in patients’ health-related quality of life, and can be used as a marker of achieving patient satisfaction following TKA. Cite this article: Bone Joint Res 2022;11(7):477–483

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Nearly 99,000 total knee arthroplasties (TKAs) are performed in UK annually. Despite plenty of research, the satisfaction rate of this surgery is around 80%. One of the important intraoperative factors affecting the outcome is alignment. The relationship between joint obliquity and functional outcomes is not well understood. Therefore, a study is required to investigate and compare the effects of two types of alignment (mechanical and kinematic) on functional outcomes and range of motion.

Aims. Cementless total knee arthroplasty (TKA) offers the potential for strong biological fixation compared with cemented TKA where fixation is achieved by the mechanical integration of the cement. Few mid-term results are available for newer cementless TKA designs, which have used additive manufacturing (3D printing). The aim of this study was to present mid-term clinical outcomes and implant survivorship of the cementless Stryker Triathlon Tritanium TKA. Methods. This was a single institution registry review of prospectively gathered data from 341 cementless Triathlon Tritanium TKAs at four to 6.8 years follow-up. Outcomes were determined by comparing pre- and postoperative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) scores, and pre- and postoperative 12-item Veterans RAND/Short Form Health Survey (VR/SF-12) scores. Aseptic loosening and revision for any reason were the endpoints which were used to determine survivorship at five years. Results. At mid-term follow-up, the mean KOOS JR score improved significantly from 33.14 (0 t0 85, standard deviation (SD) 21.88) preoperatively to 84.12 (15.94 to 100, SD 20.51) postoperatively (p < 0.001), the mean VR/SF-12 scores improved significantly from physical health (PH), 31.21 (SD 5.32; 23.99 to 56.77) preoperatively to 42.62 (SD 10.72; 19.38 to 56.82) postoperatively (p < 0.001) and the mental health (MH), 38.15 (SD 8.17; 19.06 to 60.75) preoperatively to 55.09 (SD 9.64; 19.06 to 66.98) postoperatively (p < 0.001). A total of 11 revisions were undertaken, with an overall revision rate of 2.94%, including five for periprosthetic joint infection (1.34%), three for loosening (0.80%), two for instability (0.53%), and one for pain (0.27%). The overall survivorship was 97.06% and survivorship for aseptic loosening as the endpoint was 98.40%, with a 99.5% survivorship of the 3D-printed tibial component. Conclusion. This 3D-printed cementless total knee system shows excellent survivorship at mid-term follow-up. This design and the ability to obtain cementless fixation offers promise for excellent long-term durability. Cite this article: Bone Joint J 2021;103-B(6 Supple A):32–37

Introduction. Cementless TKA offers the potential for strong fixation through biologic fixation technology as compared to cemented TKA where fixation is achieved through mechanical integration of the cement. Few mid-term results are available for newer cementless TKA designs that have used additive manufacturing (3-D printing) for component design. The purpose of this study is to present minimum 5-year clinical outcomes and implant survivorship of a specific cementless TKA using a novel 3-D printed tibial baseplate. Methods. This is a single institution registry review of the prospectively obtained data on 296 cementless TKA using a novel 3-D printed tibial baseplate with minimum 5-year follow-up. Outcomes were determined by comparing pre- and post-operative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) scores and pre- and post-operative 12 item Veterans RAND/Short Form Health Survey (VR/SF-12). Aseptic loosening as well as revision for any reason were the endpoints used to determine survivorship at 5 years. Results. At minimum 5-year follow-up, the KOOS JR score improved from 34.88 pre-operatively to 84.29 post-operatively (p-values = 0.0001), the VR/SF-12 scores improved from PH − 31.98 pre-operatively to 42.80 post-operatively (p-values = 0.0001) and the MH − 37.24 pre-operatively to 55.16 post-operatively (p-value = 0.0001). Eleven revisions were performed for an overall revision rate of 2.94% - including 5 PJI (1.34%), 3 loosening (0.80%), 1 instability (0.27%), 2 pain (0.53%). The overall 5-year survivorship was 97.1% and survivorship for aseptic loosening as the endpoint was 98.40%. The survivorship of the 3-D printed porous tibial component was 99.2%. Conclusion. This 3-D printed tibial baseplate and cementless total knee system shows excellent survivorship at 5-year follow-up. The design of this implant and the ability to obtain cementless fixation offers promise for excellent long-term durability

Purpose. Patient expectations of total knee arthroplasty (TKA) can be managed through education. E-learning is the application of information technology to education. Providing information to patients at the place and time of their choosing, e-learning has the potential to broaden the reach of existing services for patients. This study evaluated whether an e-learning tool could affect whether patients felt their expectations were met and whether they were satisfied with surgery one year following primary TKA. Method. We recruited consecutive patients with osteoarthritis and randomized them to either standard patient education (n=207), or to our standard patient education plus a new e-learning tool (n=209). Preoperative measures were completed following the patients’ Pre-Admission clinic (PAC) visit and prior to accessing the e-learning tool. Postoperative patient reported outcome measures (PROMs) were completed at six weeks, three months and one year after TKA. We used the Postoperative Expectation Questionnaire to measure the degree to which patient expectations had been met and the Patient Acceptable Symptom State (PASS) question to measure patient satisfaction at one year postoperative. We collected several PROMs for descriptive purposes including: new Knee Society Knee Scoring System (KSS); (Pre-Op and Post-Op versions), Knee injury and Osteoarthritis Outcome Score (KOOS), the Medical Outcomes Study 12-Item Short Form Health Survey, version 2 (SF-12), Hospital Anxiety and Depression Scale (HADS), Pain Catastrophizing Scale (PCS), University of California at Los Angeles (UCLA) Activity Score, and the Social Role Participation Questionnaire (SRPQ). Results. Both groups were similar with respect to their preoperative PROMs. Preoperative patient satisfaction was low, with few patients satisfied with their present state prior to TKA and similar between groups (14% intervention group, 11% control group). At one year postoperatively, the risk that expectations of patients were not met was 21.8% in the control group and 21.4% in the intervention group for a risk difference of 1.3% (95% CI −7.8% to 10.4%, p = 0.78). The proportion of patients satisfied with their TKA at one year postoperative was similar in the intervention group 78.6% and the control group 78.2%, and the risk difference 0.6% (95% CI −8.4% to 9.6%) was not statistically significant (p = 0.78). At one year postoperative we found significant postoperative between-group differences in favour of the control group for the new KSS symptoms score and the functional activities score. We also found that control patients had less anxiety, lower scores for rumination, magnification, and helplessness than intervention patients on the PCS. Conclusion. Patients randomized to the e-learning tool had significantly better KSS symptom scores and functional activities scores as well as lower anxiety and helplessness scores but they did not have a reduced risk of expectations not being met or an improved overall satisfaction with their TKA

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The aim of this study was to compare the migration of the femoral component, five years postoperatively, between patients with a highly cross-linked polyethylene (HXLPE) insert and those with a conventional polyethylene (PE) insert in an uncemented Triathlon fixed insert cruciate-retaining total knee arthroplasty (TKA). Secondary aims included clinical outcomes and patient-reported outcome measures (PROMs). We have previously reported the migration and outcome of the tibial components in these patients.

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The aim of this study was to report patient and clinical outcomes following robotic-assisted total knee arthroplasty (RA-TKA) at multiple institutions with a minimum two-year follow-up.

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Higher osteoblastic bone activity is expected in aseptic loosening and painful unicompartmental knee arthroplasty (UKA). However, insights into normal bone activity patterns after medial UKAs are lacking. The aim of this study was to identify the evolution in bone activity pattern in well-functioning medial mobile-bearing UKAs.

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This study compared the cobalt and chromium serum ion concentration of patients treated with two different metal-on-metal (MoM) hinged total knee arthroplasty (TKA) systems, as well as a titanium nitride (TiN)-coated variant.

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The aim of this study was to evaluate the long-term inducible displacement of cemented tibial components ten years after total knee arthroplasty (TKA).

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The purpose of the present study was to examine the long-term fixation of a cemented fixed-bearing polished titanium tibial baseplate (Genesis ll).

Modifications in the design of knee replacements have been proposed in order to maximise flexion. We performed a prospective double-blind randomised controlled trial to compare the functional outcome, including maximum knee flexion, in patients receiving either a standard or a high flexion version of the NexGen legacy posterior stabilised total knee replacement. A total of 56 patients, half of whom received each design, were assessed pre-operatively and at one year after operation using knee scores and analysis of range of movement using electrogoniometry. For both implant designs there was a significant improvement in the function component of the knee scores (p < 0.001) and the maximum range of flexion when walking on the level, ascending and descending a slope or stairs (all p < 0.001), squatting (p = 0.020) and stepping into a bath (p = 0.024). There was no significant difference in outcome, including the maximum knee flexion, between patients receiving the standard and high flexion designs of this implant.