Predicting anterior cruciate ligament degeneration using magnetic resonance imaging: Insights from histological evaluation.

BACKGROUND: Mucoid degeneration of the anterior cruciate ligament is a pathological condition that may impair knee mechanics and contribute to the symptomatology of osteoarthritis. This study aimed to evaluate whether preoperative magnetic resonance imaging can predict anterior cruciate ligament degeneration, specifically mucoid degeneration, and to elucidate the histopathological characteristics of mucoid degeneration in knee osteoarthritis patients. METHODS: We evaluated a total of 95 knees of osteoarthritis patients (23 males, 72 females; mean age: 72.7 ± 7.5) scheduled for total knee arthroplasty. The relationship between preoperative magnetic resonance imaging findings and the histopathological evidence of anterior cruciate ligament mucoid degeneration was examined. Immunohistochemical analysis was employed for collagen types (COL-I, COL-II), chondrogenesis (SOX9), and vascularity (CD31). RESULTS: High signal intensity on magnetic resonance imaging showed a positive correlation with Alcian Blue staining areas (rs = 0.59, p < 0.01) and the swelling index (rs = 0.62, p < 0.01), indicating advanced mucoid degeneration. The absence of synovial lining around the anterior cruciate ligament was associated with more severe degeneration. In the histological evaluations, advanced degeneration was characterized by an increase in chondroid metaplasia and collagen disorientation. The Alcian Blue and SOX9 correlation was positive (rs = 0.69, p < 0.01), but negative with COL-I (rs = -0.38, p = 0.03) and vascularity (CD31) (rs = -0.60, p < 0.01). CONCLUSIONS: Preoperative magnetic resonance imaging is an effective tool in assessing the severity of anterior cruciate ligament degeneration; it influences surgical decisions. High signal intensity on magnetic resonance images denotes advanced mucoid degeneration. The absence of synovial lining around the anterior cruciate ligament is associated with more severe degeneration and may accelerate degenerative changes. Chondroid metaplasia and collagen disorientation mark advanced degeneration. Magnetic resonance imaging can be used to gauge the degree of anterior cruciate ligament degeneration in osteoarthritis.

Study of Reliability and Validity of the Load Cell-Type Hand Dynamometer Compared to the Jamar Dynamometer and the Number of Reliable Grip Strength Measurements.

Background: Standardised measurement protocols for grip strength remained unclear due to variations in values depending on the device and measurement method. The load cell hand dynamometer has recently been developed. This study aims to investigate the reliability of the load cell dynamometer by comparing it to the Jamar dynamometer, which is considered the gold standard, and to identify a reliable and practical measurement method. Methods: This study included 80 healthy hospital workers (mean age of 40.1 years). All measurements were performed seated, with the elbow flexed 90° and the grip span at the second handle (approximately 50 mm) for the Jamar dynamometer, and with the elbow extended and the grip span fixed at 55 mm for the load cell dynamometer. Grip strength was measured three times on each hand using two dynamometers, and the same tests were repeated on different days. Test-retest reliability, the association between the two devices and the agreement between the two measurement methods were assessed using the intraclass correlation coefficient (ICC), Pearson correlation and the Bland-Altman analysis. Results: The ICC of the one measurement was lower than that of three measurements for both dynamometers, but was above 0.858 in all groups, indicating sufficient reliability with one-time measurement. Additionally, the ICC for different days revealed good reliability (Jamar: >0.830, load cell: >0.772). The load cell dynamometer showed significantly lower values in all measurements despite the excellent correlation (r > 0.70) and the agreement between the two dynamometers. Conclusions: This study revealed sufficient reliability of the load cell dynamometer with the standardised measurement method, but it should be noted the lower values compared to the Jamar dynamometer. Additionally, one-time measurement reliability is adequate for practical use by standardising the measurement methods for both dynamometers. Level of Evidence: Level III (Diagnostic).

Lower limb alignment in healthy Japanese adults.

BACKGROUND: Knowledge regarding the normal alignment of the lower limb is important when considering alignment for total knee arthroplasty. However, few studies have explored the lower limb alignment of healthy Japanese subjects. METHODS: Between July and October 2020, we performed whole leg standing radiography of 120 legs of 60 healthy adult Japanese volunteers aged <50 years in the closed-leg stance. The measurement parameters were hip knee ankle angle (positive for varus), percentage of constitutional varus (hip knee ankle angle ≥ 3°), mechanical axis deviation ratio, mechanical lateral distal femoral angle, medial proximal tibial angle, joint line convergence angle (positive for lateral opening), and tibial joint line angle (positive for medial inclination). RESULTS: The mean measured values for all volunteers, men and women, were as follows: hip knee ankle angle (°), 2.3, 2.6, and 2.0; mechanical axis deviation ratio, 35.8, 35.6, and 36.9; mechanical lateral distal femoral angle (°), 86.7, 87.0, and 86.7; medial proximal tibial angle (°), 85.6, 85.0, and 86.2; joint line convergence angle (°), 0.6, 0.3, and 0.8; and tibial joint line angle (°), -1.0, -0.7, -1.4, respectively. The percentage of constitutional varus was 35.8% overall, 35.8% in men and 35.3% in women. Only the medial proximal tibial angle was smaller in men than that in women (p = 0.003). CONCLUSIONS: The mechanical lateral distal femoral and medial proximal tibial angles were smaller, hip knee ankle angle was larger, and percentage of constitutional varus was higher in Japanese subjects than those reported for subjects in other countries. Our findings improve the understanding of Japanese-specific alignments when considering alignment for lower limb surgery, especially, total knee arthroplasty.

Evaluation of hindfoot and knee alignment by the hip-to-calcaneus view in patients with knee osteoarthritis and healthy individuals.

BACKGROUND: Hip-to-calcaneus (HC) view is a whole-leg standing view that can visualize the hindfoot in detail. The aim of this study was to investigate the reliability and validity of tibiocalcaneal angle in HC view (H-TCA) by comparing it with that in long axial view (L-TCA). We also verified whether periarticular knee alignment parameters, measured conventionally in whole-leg standing radiography, could be measured in HC view. METHOD: Sixty healthy volunteers and 61 patients with medial knee osteoarthritis were included. H-TCA was measured by two examiners in the healthy group, and intra-class correlation coefficients (ICCs) were evaluated. H-TCA and L-TCA were then measured in the healthy and osteoarthritis groups and correlated. Finally, we measured hip-knee-ankle angle, mechanical axis deviation ratio, mechanical lateral distal femoral angle, medial proximal tibial angle, and joint-line convergence angle in HC view and conventional whole-leg standing radiography to evaluate statistical differences and correlations. RESULTS: The intra-observer and inter-observer ICCs were 0.86 and 0.76, respectively. Correlation coefficients (r) between H-TCA and L-TCA were r = 0.87 in healthy group and r = 0.81 in osteoarthritis group, indicating a strong positive correlation in both groups. There was no significant difference in periarticular knee alignment parameters between HC view and conventional whole-leg radiography. CONCLUSIONS: Hindfoot evaluation in HC view showed high intra-observer and inter-observer reliabilities and strong positive correlation with TCA in long axial view. By using HC view before knee surgery, such as total knee arthroplasty, other necessary alignments can be evaluated simultaneously.

Forefoot Deformities in Patients with Rheumatoid Arthritis: Mid- to Long-Term Result of Joint-Preserving Surgery in Comparison with Resection Arthroplasty.

BACKGROUND: Joint-preserving surgery for the forefoot has been increasingly performed for rheumatoid arthritis (RA). We compared joint-preserving surgeries with resection arthroplasty for RA in the forefoot. METHODS: Forefoot surgeries were performed on 62 toes in 42 patients with RA (men: 2; women: 40) between 2002 and 2018. Three groups were compared: PP-31 toes treated with joint-preserving surgery involving the modified Mann method for the big toe and offset osteotomy for lesser toes, PR-15 toes treated with joint-preserving surgery for the big toe and resection arthroplasty for lesser toes, and RR-16 toes treated with resection arthroplasty for all the toes. RESULTS: The PP group had significantly higher mean scores on a scale for RA in the foot and ankle at the latest follow-up than the RR group (86 vs. 75 points; p < 0.05). Hallux valgus (angle > 20°) of the big toe at the latest follow-up recurred in 10 (32%), 9 (60%), and 16 (100%) patients in the PP, PR, and RR groups, respectively. A revision surgery was performed in one patient each in the PP and PR groups. CONCLUSIONS: Joint-preserving surgery is superior to resection arthroplasty in preventing function loss and the recurrence of hallux valgus.