Loosening is the leading cause of total knee arthroplasty (TKA) revision. This is a heavy burden toward the healthcare system owing to the difficulty in diagnosis and complications occurring from the delay management. Based on automatic analytical model building, machine learning, may potentially help to automatically recognize the risk of loosening based on radiographs alone. The aim of this study was to build an image-based machine-learning model for detecting TKA loosening. Image-based machine-learning model was developed based on ImageNet, Xception model and a TKA patient X-ray image dataset. Based on a dataset with TKA patient clinical parameters, another system was then created for developing the clinical-information-based machine learning model with random forest classifier. In addition, the Xception Model was pre-trained on the ImageNet database with python and TensorFlow deep learning library for the prediction of loosening. Class activation maps were also used to interpret the prediction decision made by model. Two senior orthopaedic specialists were invited to assess loosening from X-ray images for 3 attempts in setting up comparison benchmark. In the image-based machine learning loosening model, the precision rate and recall rate were 0.92 and 0.96, respectively. While for the accuracy rate, 96.3% for visualization classification was observed. However, the addition of clinical-information-based model, with precision rate of 0.71 and recall rate of 0.20, did not further showed improvement on the accuracy. Moreover, as class activation maps showed corresponding signals over bone-implant interface that is loosened radiographically, this confirms that the current model utilized a similar image recognition pattern as that of inspection by clinical specialists. The image-based machine learning model developed demonstrated high accuracy and predictability of knee arthroplasty loosening. And the class activation heatmap matched well with the radiographic features used clinically to detect loosening, which highlighting its potential role in assisting clinicians in their daily practice. However, addition of clinical-information-based machine-learning model did not offer further improvement in detection. As far as we know, this is the first report of pure image-based machine learning model with high detection accuracy. Importantly, this is also the first model to show relevant class activation heatmap corresponding to loosening location. The finding in this study indicated image-based machine learning model can detect knee arthroplasty loosening with high accuracy and predictability, which the class activation heatmap can potentially assist surgeons to identify the sites of loosening.

This prospective cohort study was designed to evaluate the survivorship and functional outcomes associated with long-term results of medial open-wedge high tibial osteotomy (MOWHTO) for the treatment of medial compartment knee osteoarthritis in the Chinese population. Although MOWHTO is a well-established procedure in the management of medial osteoarthritis of the knee, the long-term outcome in the Chinese population has not been reported in current literature. We hypothesised that MOWHTO would result in long-term preservation of knee function in Chinese, similar to that reported in the Caucasian population. A cohort of 22 young adult patients (age < 55 years old) undergoing MOWHTO for the treatment of symptomatic medial compartment knee osteoarthritis between 2002 and 2008 was retrospectively surveyed with a minimum follow-up of 10 years. Kaplan–Meier survival analysis was performed, and the failure modes were investigated. The outcomes on survival (not requiring arthroplasty), clinical outcome (Knee Society Knee Score and Knee Society Function Score) and range of motion (numeric rating scale) at preoperative, 1-year postoperative follow-up and at last follow-up (>10 years) were evaluated. In addition, the mechanical tibiofemoral angle was also measured. The Wilcoxon signed-rank test was used for statistical evaluation of nonparametric data in these related samples. A total of 31 knees in these 22 cases were included. The follow-up rate was 100% at 13.4 ± 1.9 years (11–17). Mean age at time of surgery was 45.8 ± 9.5 years (18–53). At 10-year follow-up, four knees converted to require total knee arthroplasty (survival: 87.1%). Preoperative varus alignment with mechanical tibiofemoral angle of −9.26 ± 2.83 was corrected to 2.58 ± 2.46 after surgery and remained 2.01 ± 3.52 at the latest follow-up. Knee Society Knee Score increased significantly from 53.7 ± 11.1 preoperatively to 93.8 ± 6.8 at 1-year follow-up and 91.8 ± 9.7 at latest follow-up. Similarly, the functional score also increased significantly from 67.4 ± 21.0 preoperatively to 86.3 ± 14.5 at 1-year follow-up and 82.1 ± 16.6 at latest follow-up (p < 0.01). Whereas, the range of motion significantly decreased from 122.7 ± 6.6 preoperatively to 116.1 ± 15.5 at the latest follow-up. Even in cases of severe medial osteoarthritis and varus malalignment, MOWHTO would be a good treatment option for management in active Chinese population less than 55 years. Although the long-term survival and functional outcome after MOWHTO was proven to be satisfactory in our cohort during the 10-year follow-up, a larger cohort to illustrate the long-term functional outcome is still warranted. The finding in this study indicated MOWHTO is a feasible treatment option for young adult patients with osteoarthritis to achieve long-term satisfactory results.

Tendon healing is slow and usually results in inferior fibrotic tissue formation. Recently, application of tendon derived stem cells (TDSCs) improved tendon healing in animal studies. In a chicken model, local injection of antioxidants reduced tendon adhesion after tendon injury. An in vitro study demonstrated that supplementation of H₂O₂ reduced tenogenic marker expression in TDSCs. These findings suggested that the possibility of TDSCs is involved in tendon healing and the cellular activities of TDSCs might be affected by oxidative stress of the local environment. After tendon injury, oxidative stress is increased. Redox modulation might affect healing outcomes via affecting cellular activities in TDSCs. To study the effect of oxidative stress on TDSCs, the cellular activities of rat/human TDSCs were measured under different dosages of vitamin C or H₂O₂ in this study. Lower dose of vitamin C increased cell proliferation, viability and migration; H₂O₂ affected colony formation and suppressed cell migration, cell viability, apoptosis, and proliferation. Consistent with previous studies, oxidative stresses (H₂O₂) affect both recruitment and survival of TDSCs, while the antioxidant vitamin C may exert beneficial effects at low doses. In conclusion, redox modulation affected cellular activities of TDSCs and might be a potential strategy for tendon healing treatment.

Background: The high co-prevalence of obesity and end-stage osteoarthritis requiring arthroplasty, with the former being a risk factor for complications during arthroplasty, has led to increasing interest in employing preoperative weight loss interventions such as bariatric surgery and diet modification. However, the current evidence is conflicting, and this study aimed to investigate the effect of weight loss intervention before arthroplasty in prospective randomized controlled trials. Methods: Four electronic databases (MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials) were searched for prospective randomized controlled trials that compared weight loss interventions with usual care from inception to October 2023 by following the PRISMA guidelines. The Cochrane risk of bias tool and GRADE framework were used to assess the quality of the studies. Meta-analyses were performed when sufficient data were available from 2 or more studies. Results: Three randomized controlled trials involving 198 patients were identified. Two studies employed diet modification, and one study utilized bariatric surgery. All three studies reported significant reductions in body weight and body mass index (BMI), and intervention groups had fewer postoperative complications. There was no difference in the length of stay between the intervention group and the control group. Variable patient-reported outcome measures were used by different research groups. Conclusion: Weight loss intervention can achieve significant reductions in body weight and body mass index before arthroplasty, with fewer postoperative complications reported. Further studies with different populations could confirm the effect of these interventions among populations with different obesity characteristics.

Background: The development of total knee arthroplasty (TKA) for knee osteoarthritis (OA) has a good reputation for its effectiveness in reducing joint pain and improving range of motion. We aimed to review our early results using the image‐free robotic‐assisted technology in knee arthroplasty.Methods: A total of 71 patients suffering from end‐stage OA knee receiving TKA operated by robotic‐assisted surgery between the years 2018 and mid‐2021 were recruited. Clinical and radiological outcomes were compared with age and sex‐matched control group (conventional TKA).Results: The radiological outcome showed significantly more postoperative lower limb alignment outliers in conventional side than robotic‐assisted sides. Postoperative knee scores were similar among both groups. Robotic‐assisted TKA required a longer implantation time but a shorter hospital stay.Conclusion: Robotic‐assisted TKA achieved a lower rate of mechanical axis Outlier in the coronal and sagittal plane with a shorter hospital stay. Yet both methods achieve a similar functional outcome.

Background: One factor in the long-term survivorship of unicompartmental knee arthroplasty is the accuracy of implantation. In addition to implant designs, the instrumentation has also evolved in the last three decades to improve the reproducibility of implant placement. There have been limited studies comparing mobile bearing unicompartmental knee arthroplasty with contemporary instrumentation and fixed bearing unicompartmental knee arthroplasty with conventional instrumentation. This study aims to determine whether the Microplasty instrumentation in Oxford unicompartmental knee arthroplasty allows the surgeon to implant the components more precisely and accurately. Methods: A total of 150 patients (194 knees) were included between April 2013 and June 2019. Coronal and sagittal alignment of the tibial and femoral components was measured on postoperative radiographs. Component axial rotational alignment was measured on postoperative computer tomography. The knee rotation angle was the difference between the femoral and tibial axial rotation. A rotational mismatch was defined as a knee rotation angle of > 10°. Statistical analysis was performed using Student t test and Mann-Whitney nonparametric test. A p value < 0.05 was considered statistically significant in each analysis. Results: Between April 2013 to June 2019, 112 patients (150 knees) received Oxford unicompartmental knee arthroplasty, one patient (2 knees) had Journey unicompartmental knee arthroplasty, and 37 patients (42 knees) received Zimmer unicompartmental knee arthroplasty. All femoral components in the Oxford group were implanted within the reference range, compared with 36.6% in the fixed bearing group (p < 0.001). 88.3% of Oxford knees had tibial component falling within the reference range, whereas 56.1% of knees in the fixed bearing group fell within the reference range (p < 0.001). 97.5% of Oxford knees had tibial slope that fell within reference range, whereas 53.7% fell within range for fixed bearing group (p < 0.001). Femorotibial rotational mismatch of more than 10° was noted in 13.8% in Oxford group and 20.5% in fixed bearing group (p = 0.04). Conclusion: In conclusion, Microplasty instrumentation for Oxford mobile bearing unicompartmental knee arthroplasty is more accurate and precise compared to conventional fixed bearing unicompartmental knee arthroplasty in sagittal, coronal, and axial alignment. Prospective studies with long-term follow-up are warranted to investigate the clinical implications.