Methods: Fifty-five primary knee OA (median age 69.0, interquartile range [IQR] 11.0) participated in the cross-sectional study. Three performance-based tests were performed in two sessions with a 1-week interval; 30-s chair stand test, 40-m fast-paced walk test and 9-step stair climb test. Relative reliability included intra-class correlation and Spearman's correlation coefficient (SPC). Absolute reliability included standard error of measurement, minimum detectable change, coefficient of variance, limit of agreement (LOA) and ratio LOA. Knee Injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS), knee extensor strength and pain scale were analysed for convergent validity using Pearson's correlation coefficient and SPC. Analysis of Covariance was utilised for known-groups validity.
Results: Relative and absolute reliability were all acceptable. LOA showed small systematic bias. Acceptable construct validity was only found with knee extensor strength. All tests demonstrated known-groups validity with medium to large effect size.
Conclusion: The OARSI minimum core set of performance-based tests demonstrated acceptable relative and absolute reliability and good known-groups validity but poor convergent validity.
Material and method: Computer-assisted total knee arthroplasty (TKA) or primary osteoarthritis of the knee was performed in 51 knees in 36 patients with a mean age of 69.51 years. All procedures were performed by a single surgeon using the same implant design. The intraclass correlation coefficient (ICC) was used to compare the intra-operative CAN-FRA with the post-operative CT-FRA. The angle between the anatomical epicondylar axis and the posterior condylar axis of the implant (CT-FRA) was measured at two separate timepoints by three observers who were blinded to the intra-operative CAN-FRA. Internal rotation was defined as rotation in the negative direction, while external rotation was defined as positive.
Results: The mean intra-operative CAN-FRA was 0.1° ± 2.8° (range -5.0° to 5.5°). The mean post-operative CT-FRA was -1.3° ± 2.1° (range -4.6° to 4.4°). The mean difference between the CAN-FRA and the CT-FRA was -1.3° ± 2.2° (range -7.9° to 2.4°). The respective ICC values for the three observers were 0.92, 0.94, and 0.93, while the respective intra-observer coefficients were 0.91, 0.85, and 0.90. The ICC for the intra-operative CAN-FRA versus the post-operative CT-FRA was 0.71.
Conclusion: This study shows that using a computer-assisted navigation system in TKA achieves reliable results and helps to achieve optimal positioning of the femoral component and rotation alignment correction.
METHODS: Fifty computed tomography scans of nonarthritic knees were evaluated using three-dimensional image processing software. Four distal femoral rotational axes were determined in the axial plane: the transepicondylar axis (TEA), transcondylar axis (TCA), posterior condylar axis (PCA), and a line perpendicular to Whiteside's anterior-posterior axis. Then, angles were measured relative to the TEA. Tibial joint line obliquity was measured as the angle between the proximal tibial plane and a line perpendicular to the axis of the tibia.
RESULTS: There was a strong positive correlation between PCA-TEA and tibial joint line obliquity (r = 0.68, P < .001) as well as TCA-TEA and tibial joint line obliquity (r = 0.69, P < .001). In addition, the tibial joint line obliquity and TCA-TEA angles were similar, 3.7° ± 2.2° (mean ± standard deviation) and 3.5° ± 1.7°, respectively (mean difference, 0.2° ± 0.2°; P = .369).
CONCLUSION: Both PCA-TEA and TCA-TEA strongly correlated with proximal tibial joint line obliquity indicating a relationship between distal femoral rotational geometry and proximal tibial inclination. These findings could imply that the native knee in flexion attempts to balance the collateral ligaments toward a rectangular flexion space. A higher tibial varus inclination is matched with a more internally rotated distal femur relative to the TEA.
METHODS: This single-blind, prospective, randomized, controlled trial involved intraoperative measurements for 271 femoral component implantations from 3 contemporary TKA systems, with 2 systems offering narrow sizing options. The difference between femoral component dimensions and the resected surface of distal femur was measured in millimeters at 5 distinct zones.
RESULTS: Overhang of standard femoral component was common in the anterior-medial condyle and anterior-lateral condyle ranging from 50.8% to 99.0% and 21.5% to 88.0%, respectively. With narrow femoral components, the rate of overhang reduced to 21.5%-30.2% and 9.2%-32.1%. Conversely, underhang rates were higher over the anterior flange width, middle medial-lateral and posterior medial-lateral zones. Standard components displayed higher underhang rates at these zones compared to narrow components. The good fit rate for femoral component was low among the 3 systems ranging from 1.0% to 56.0%. System with narrow option sizing increases the underhang rates in males, while improving the component fit among females at similar zones with rate ranging from 5.2% to 52.9%.
CONCLUSION: Currently available TKA implant designs may not provide a perfect match for the distal femoral shape of the Korean population. The availability of implants with standard and narrow options can substantially improve the optimal fitting of femoral components in the Korean population.
METHODS: All the 127 patients, who received either three repeated doses (n = 64) or a single dose (n = 63) of GO-ON in the previous trial, were followed up in month 12 following the treatment. The effectiveness of both the regimens was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the mean WOMAC scores were compared with those recorded at the baseline and in month 3. Additionally, the total treatment costs of the two regimens, taking account of both direct and indirect costs, were computed and compared.
RESULTS: A total of 125 patients (98.4%) completed the assessment. Despite the reduction of the overall mean WOMAC score from 39.24 to 19.93 (p < 0.001) in the first 3 months following the treatment with GO-ON, no further changes were observed up to month 12 (p > 0.95). In the meantime, the two regimens did not differ in the mean WOMAC scores (p = 0.749) and in the subscale scores for pain (p = 0.970), stiffness (p = 0.526), and physical functioning (p = 0.667) in month 12. The cost for single-dose injection was found to be approximately 30% lower compared to the repeated doses.
CONCLUSION: These findings indicate that the single larger dose of GO-ON is as effective as the repeated doses over 12 months, and yet the total treatment cost is lowered.