METHODS: Nine full-text articles in English that reported the clinical and radiological outcomes of KA TKA were included. Five studies had a control group of patients who underwent MA TKA. Data on patient demographics, clinical scores, and radiological results were extracted. There were two level I, one level II, three level III, and three level IV studies. Six of the nine studies used patient-specific instrumentation, one study used computer navigation, and two studies used manual instrumentation.
RESULTS: The clinical outcomes of KA TKA were comparable or superior to those of MA TKA with a minimum 2-year follow-up. Limb and knee alignment in KA TKA was similar to those in MA TKA, and component alignment showed slightly more varus in the tibial component and slightly more valgus in the femoral component. The JLOA in KA TKA was relatively parallel to the floor compared to that in the native knee and not oblique (medial side up and lateral side down) compared to that in MA TKA. The implant survivorship and complication rate of the KA TKA were similar to those of the MA TKA.
CONCLUSION: Similar or better clinical outcomes were produced by using a KA TKA at early-term follow-up and the component alignment differed from that of MA TKA. KA TKA seemed to restore function without catastrophic failure regardless of the alignment category up to midterm follow-up. The JLOA in KA TKA was relatively parallel to the floor similar to the native knee compared to that in MA TKA. The present review of nine published studies suggests that relatively new kinematic alignment is an acceptable and alternative alignment to mechanical alignment, which is better understood. Further validation of these findings requires more randomized clinical trials with longer follow-up.
LEVEL OF EVIDENCE: Level II.
METHODS: Three different cams (triangle, ellipse, and circle) and three different posts (straight, convex, concave) geometries were considered in this study and were analysed using kinematic analyses. Femoral rollback did not occur until reaching 50° of knee flexion. Beyond this angle, two of the nine combinations demonstrate poor knee flexion and were eliminated from the study.
RESULTS: The combination of circle cam with concave post, straight post and convex post showed 15.6, 15.9 and 16.1 mm posterior translation of the femur, respectively. The use of ellipse cam with convex post and straight post demonstrated a 15.3 and 14.9 mm femoral rollback, whilst the combination of triangle cam with convex post and straight post showed 16.1 and 15.8 mm femoral rollback, respectively.
CONCLUSION: The present study demonstrates that the use of circle cam and convex post created the best femoral rollback effect which in turn produces the highest amount of knee flexion. The findings of the study suggest that if the design is applied for knee implants, superior knee flexion may be possible for future patients.
LEVEL OF EVIDENCE: IV.
METHODS: 20-Plex proteins were quantified using Human Magnetic Luminex® assay (R&D Systems, USA) from plasma and SF of OA (n = 14) and non-OA (n = 14) patients. Ingenuity Pathway Analysis (IPA) software was used to predict the relationship and possible interaction of molecules pertaining to OA.
RESULTS: There were significant differences in plasma level for matrix metalloproteinase (MMP)-3, interleukin (IL)-27, IL-8, IL-4, tumour necrosis factor-alpha, MMP-1, IL-15, IL-21, IL-10, and IL-1 beta between the groups, as well as significant differences in SF level for IL-15, IL-8, vascular endothelial growth factor (VEGF), MMP-1, and IL-18. Our predictive OA model demonstrated that toll-like receptor (TLR) 2, macrophage migration inhibitory factor (MIF), TLR4 and IL-1 were the main regulators of IL-1B, IL-4, IL-8, IL-10, IL-15, IL-21, IL-27, MMP-1 and MMP-3 in the plasma system; whilst IL-1B, TLR4, IL-1, and basigin (BSG) were the regulators of IL-4, IL-8, IL-10, IL-15, IL-18, IL-21, IL-27, MMP-1, and MMP-3 in the SF system.
CONCLUSION: The elevated plasma IL-8 and SF IL-18 may be associated with the pathogenesis of OA via the activation of MMP-3.
METHODS: From April 2014 to December 2015, a total of 72 knees in 64 patients that underwent OWHTO, second-look arthroscopy, and magnetic resonance imaging (MRI) assessment, were enrolled. Preoperative and postoperative coronal and sagittal translation, joint line orientation angle, the distance between medial femoral notch marginal line and medial tibial spine, and PTS were evaluated. ACL status was arthroscopically graded from grade 1 (best) to 4 (worst). The MRI signal of the graft in three portions (proximal, middle, and distal) was graded from grade 1 (best) to 4 (worst).
RESULTS: High grade (3: partial, and 4: complete rupture) was noted in 28 cases (38.9%) at the second-look arthroscopy compared with 10 cases (13.9%) at index arthroscopy. The MRI signal grade significantly increased at follow up MRI compared with preoperative MRI (P<0.01). An increased signal was commonly noted in the middle and distal portions of the graft.
CONCLUSIONS: Geometric changes after OWHTO were related to ACL deterioration. The ACL was commonly affected at the middle and distal portions and rarely at the proximal portion. There is a possibility of impingement because of the geometric changes.
LEVEL OF EVIDENCE: Level IV.
Materials and Methods: Gait analysis was performed in 20 patients with endoprosthesis replacement around the knee. The temporal parameters assessed during gait analysis were walking velocity, stride length, duration of stance, and goniometry of the knee. These parameters were compared with the functional outcome score of the MSTS.
Results: The mean free-paced walking velocity was 0.91 m/s (normal is 1.33 m/s), which was 68% lower than normal gait. The stride length and stance phase were shorter for the affected limb compared to normal (P < 0.05). However, the gait was symmetrical with no difference in stride length (P = 0.148), velocity (P = 0.918), knee flexion (P = 0.465), and knee extension (P = 0.321) between the affected and unaffected limbs. Sixteen patients demonstrated stiff knee gait, two had a flexed knee gait, and only two patients had normal gait during the stance phase. The mean MSTS score was 21. There was significant correlation between overall MSTS scores (P = 0.023), function (P = 0.039), and walking scores (P = 0.007).
Conclusion: Limb salvage surgery with endoprosthesis reconstruction around the knee gives good functional outcome, both objectively and subjectively, as evidenced by the symmetrical gait pattern and significant correlation with MSTS score. Despite decreased walking velocity, stride length, and stance phase of the operated limb, the patient still has a symmetrical gait.
Results: Based on MRI, Thessaly was the most sensitive for medial meniscus tears (56.2%), while McMurray and joint-line tenderness were more specific (89.1% and 88.0%, respectively). For lateral meniscus tears, McMurray was the most sensitive (56.2%) and all were specific (McMurray 89.6%, Thessaly 88.4%, joint-line tenderness 90.2%). With arthroscopy, Thessaly was the most sensitive for medial meniscus (76.6%), while McMurray and joint-line tenderness were more specific (81.0%, and 81.0%). Agreement with arthroscopy was the highest with McMurray (for medial meniscus kappa=0.40, p<0.001, and for lateral meniscus kappa=0.38, p=0.002).
Conclusion: The Thessaly can be used to screen for medial meniscus tears. McMurray and joint-line tenderness should be used for suspected medial meniscus tears. For lateral meniscus, McMurray is appropriate for screening and all the tests are useful in clinic.
METHODS: The model was developed to estimate knee torque from experimentally derived MMG signals and other parameters related to torque production, including the knee angle and stimulation intensity, during NMES-assisted knee extension.
RESULTS: When the relationship between the actual and predicted torques was quantified using the coefficient of determination (R2), with a Gaussian support vector kernel, the R2 value indicated an estimation accuracy of 95% for the training subset and 94% for the testing subset while the polynomial support vector kernel indicated an accuracy of 92% for the training subset and 91% for the testing subset. For the Gaussian kernel, the root mean square error of the model was 6.28 for the training set and 8.19 for testing set, while the polynomial kernels for the training and testing sets were 7.99 and 9.82, respectively.
CONCLUSIONS: These results showed good predictive accuracy for SVR modelling, which can be generalized, and suggested that the MMG signals from paralyzed knee extensors are a suitable proxy for the NMES-assisted torque produced during repeated bouts of isometric knee extension tasks. This finding has potential implications for using MMG signals as torque sensors in NMES closed-loop systems and provides valuable information for implementing this method in research and clinical settings.