Abstract Background Medial meniscal extrusion (MME) is a valuable clinical sign for early detection of osteoarthritis (OA). Thus, post-anterior cruciate ligament reconstruction (ACLR) MME is a potential predictor of postoperative OA. We aimed to examine MME variations before and after ACLR including the influence of suture medial meniscus (MM) injuries. Methods We analysed 92 knees from 92 patients who underwent anatomic ACLR. Multiple linear regression analysis was conducted using 1-year post-operative MME as the dependent variable, and age, sex, body mass index, preoperative MME, and MM treatment as independent variables. MM treatment was categorised into three groups: no MM injury and no suture [N/N], MM injury but no suture [I/N], and MM injury and suture [I/S]. A paired t-test was performed on the three groups and all patients to compare the pre- and 1-year post-operative MME. Results The factors significantly affecting post-operative MME were preoperative MME (P = 0.004) and I/S (P < 0.001). Additionally, the paired t-test showed no significant differences between the pre- and post-operative MME in all groups. Pre- and post-operative MME in the N/N group were 1.89 ± 0.85 and 1.71 ± 0.49 mm (P = 0.17), respectively; in the I/N group, 1.87 ± 0.91 and 1.84 ± 0.73 mm (P = 0.91) respectively; and in the I/S group, 2.40 ± 1.14 and 2.80 ± 0.77 mm (P = 0.12), respectively. Conclusions Preoperative MME and I/S were significantly associated with greater MME after ACLR. The evaluation of post-ACLR outcomes using MME should consider preoperative MME and MM injuries that require suture.
The aim of this study was to evaluate the qualitative change in reparative cartilage after autologous chondrocyte implantation (ACI). Ten knees of 10 patients were studied. The signal intensities of reparative and normal cartilage were evaluated by fat-suppressed three-dimensional spoiled-gradient recalled (FS 3D-SPGR) MR imaging. The signal intensity (SI) index (signal intensity of reparative cartilage divided by that of normal cartilage) was defined and the change in SI index was investigated. Histological and biochemical evaluation was done at the second look arthroscopy. The SI index was at its lowest level immediately after ACI and increased with time to 9 months thereafter. After 9-12 months, the SI index settled to almost level and was maintained at that value for at least 2-3 years postoperatively. The average of the SI indexes after 12 months to the last examination was 74.2 +/- 4.6 (range 64.2-82.8), which means signal intensity of reparative cartilage was maintained at a value lower than that of normal cartilage. The total ICRS score was 11.6 +/- 2.3 points (mean +/- SD). The GAG concentration was 107.9 +/- 17.0 microg/mg (mean +/- SD) in normal cartilage and 65.9 +/- 9.4 microg/mg in reparative cartilage. The quality of reparative cartilage as hyaline cartilage was inferior to that of normal cartilage. In the present study, the time course change in the SI index indicates that the major maturation process of implanted chondrocytes neared completion in 9-12 months. Minor changes, such as matrix remodeling with reorganization of the collagen fibers in reparative cartilage, may continue, but an almost identical condition seemed to be maintained during the first 2-3 years of follow-up. SI index does not always reflect all properties of reparative cartilage but may be a useful parameter for noninvasive evaluation.
Objectives. To document the reliability of Abe's classification and to clarify the predictive factors for acetabular labral lesions in osteoarthritis of the hip with radial magnetic resonance (MR) imaging. Methods. Reliability trial for the classification of acetabular labral lesion was performed by six orthopedic surgeons, grading 20 radial MR images in a blinded fashion at an interval of 4–5 weeks. Radial MR images of 275 hips in 263 patients were prospectively analyzed to determine the relationship between acetabular labral lesions, their distribution, age, and the acetabular coverage. Results. Cohen's quadratic weighted kappa of inter-observer reliability was 0.784 for the grade and 0.812 for the shape category. The weighted kappa of intra-observer reliability was 0.852 for the grade and 0.90 for the shape category. Multiple regression analysis revealed that both the grade and the shape were associated with age, acetabular coverage, and location of the labrum. Conclusions. Abe's classification of labral lesions was reliable for both the grade and shape categories. Aging, acetabular dysplasia, and the anterosuperior portion would be predictive factors for degeneration of the acetabular labrum using radial MR imaging.
The development of computer-assisted technologies to diagnose anterior cruciate ligament (ACL) injury by analyzing knee magnetic resonance images (MRI) would be beneficial, and convolutional neural network (CNN)-based deep learning approaches may offer a solution. This study aimed to evaluate the accuracy of a CNN system in diagnosing ACL ruptures by a single slice from a knee MRI and to compare the results with that of experienced human readers.One hundred sagittal MR images from patients with and without ACL injuries, confirmed by arthroscopy, were cropped and used for the CNN training. The final decision by the CNN for intact or torn ACL was based on the probability of ACL tear on a single MRI slice. Twelve board-certified physicians reviewed the same images used by CNN.The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the CNN classification was 91.0%, 86.0%, 88.5%, 87.0%, and 91.0%, respectively. The overall values of the physicians' readings were similar, but the specificity was lower than the CNN classification for some of the physicians, thus resulting in lower accuracy for the human readers.The trained CNN automatically detected the ACL tears with acceptable accuracy comparable to that of human readers.
