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Abstract Introduction Tibia valga, an extra-articular valgus deformity of the tibia, is common in valgus knees and can result in component misplacement and early total knee arthroplasty (TKA) failure. However, the prevalence and importance of tibia valga in TKA have been seldom reported. This study aims to describe the prevalence and characteristics of tibia valga morphology in valgus knees and describe implications for surgical planning in primary TKA. Methods We prospectively examined pre-operative weightbearing whole-body EOS digital radiographs of patients with knee osteoarthritis listed for TKA between December 2018 and December 2020. Hip–knee–ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), joint line convergence angle (JLCA) and tibial morphology with centre of rotation of angulation of tibia (CORA-tibia) were measured and analysed. Results In 830 knees, 253 (30%) and 577 (70%) were classified as valgus and varus, respectively. In valgus knees, 89 knees (35%) had tibia valga. Median CORA-tibia was 2.8° (range 0.2°–10.9°). Tibia valga knees had no difference in mLDFA, higher HKA (5.0o versus 3.0°, p = 0.002) and mMPTA (89.6° versus 88.1°, p

Abstract Background Templating for total knee arthroplasty (TKA) is routinely performed on two-dimensional standard X-ray images and allows template-directed instrumentation. To date, there is no report on one-dimensional (1D) anteroposterior (AP) templating not requiring specific templating software. We aim to describe a novel technique and explore its reliability, accuracy and potential cost-savings. Methods We investigated a consecutive series of TKAs at one institution between January and July 2019. Patients with preoperative low-dose linear AP EOS radiography images were included. Implant component sizes were retrospectively templated on the AP view with the hospitals imaging viewing software by two observers who were blinded to the definitive implant size. Planning accuracy as well as inter- and intra-observer reliability was calculated. Cost-savings were estimated based on the reduction of trays indicated by the 1D templating size estimations. Results A total of 141 consecutive TKAs in 113 patients were included. Accuracy of 1D templating was as follows: exact match in 53% femoral and 63% tibial components, within one size in 96% femoral and 98% tibial components. Overall 58% of TKA components were planned correctly and 97% within one size. Inter- and intra-rater reliability was good (κ = 0.66) and very good (κ = 0.82), respectively. This templating process can reduce instrumentation from six to three trays per case and therefore halve sterilisation costs. Conclusions The new 1D templating method using EOS AP imaging predicts component sizes in TKA within one size 97% of the time and can halve the number of instrumentation trays and sterilisation costs.

Abstract Background A substantial proportion of patients undergoing lower limb arthroplasty are of working age. This study aims to identify when patients return to work (RTW) and if they return to normal hours and duties, and to identify which factors influence postoperative RTW. The hypothesis is that there is no difference in time of RTW between the different types of surgery, and no difference in time of RTW based on the physical demands of the job. Materials and methods Consecutive patients aged < 65 years who had undergone unilateral primary total hip arthroplasty (THA), total knee arthroplasty (TKA), or medial unicompartmental knee arthroplasty (UKA) from 2015 to 2017 were sent a questionnaire. Quantitative questions explored timing and nature of RTW, and qualitative questions explored factors influencing timing of RTW. Results There were 116 patients (64 male, 52 female) with an average age of 56 years. Thirty-one patients were self-employed and 85 were employees. Of these patients, 58 had undergone THA, 31 had undergone TKA, and 27 had undergone UKA. One hundred and six (91%) patients returned to work. Patients returned to work after (mean) 6.4 weeks (THA), 7.7 weeks (TKA), and 5.9 weeks (UKA). Time of RTW was not significantly influenced by type of surgery (p = 0.18) (ns). There was a non-significant correlation between physical demands of the work versus time of RTW (p = 0.28) (ns). There was a significantly earlier time of RTW if flexible working conditions were resumed (p = 0.003). Active recovery, motivation, necessity and job flexibility enabled RTW. The physical effects of surgery, medical restrictions and work factors impeded RTW. Conclusion The time of RTW was not significantly influenced by the type of operation or by the physical demands of the job. Patients returned to work 5.9–7.7 weeks after hip/knee arthroplasty. Rehabilitation, desire, and necessity promoted RTW. Pain, fatigue and medical restrictions impeded RTW. Level of evidence 3.

Background and purpose — Patient-specific instrumentation (PSI) for total knee arthroplasty (TKA) has been introduced to improve alignment and reduce outliers, increase efficiency, and reduce operation time. In order to improve our understanding of the outcomes of patient-specific instrumentation, we conducted a meta-analysis. Patients and methods — We identified randomized and quasi-randomized controlled trials (RCTs) comparing patient-specific and conventional instrumentation in TKA. Weighted mean differences and risk ratios were determined for radiographic accuracy, operation time, hospital stay, blood loss, number of surgical trays required, and patient-reported outcome measures. Results — 21 RCTs involving 1,587 TKAs were included. Patient-specific instrumentation resulted in slightly more accurate hip-knee-ankle axis (0.3°), coronal femoral alignment (0.3°, femoral flexion (0.9°), tibial slope (0.7°), and femoral component rotation (0.5°). The risk ratio of a coronal plane outlier (> 3° deviation of chosen target) for the tibial component was statistically significantly increased in the PSI group (RR =1.64). No significance was found for other radiographic measures. Operation time, blood loss, and transfusion rate were similar. Hospital stay was significantly shortened, by approximately 8 h, and the number of surgical trays used decreased by 4 in the PSI group. Knee Society scores and Oxford knee scores were similar. Interpretation — Patient-specific instrumentation does not result in clinically meaningful improvement in alignment, fewer outliers, or better early patient-reported outcome measures. Efficiency is improved by reducing the number of trays used, but PSI does not reduce operation time.