ABSTRACT
BACKGROUND: Ankle osteoarthritis (OA) mainly arises from trauma, particularly lateral ligament injuries. Among lateral ligament injuries, ankles with calcaneofibular ligament (CFL) injuries exhibit increased instability and can be a risk factor ankle OA progression. However, the relationship between CFL injury and OA progression remains unclear. Therefore, this study aims to assess the relationship between CFL injuries and ankle OA by investigating stress changes and osteophyte formation in subtalar joint. METHODS: We retrospectively reviewed the magnetic resonance imaging (MRI) and plain radiographic evaluations of 100 ankles of 91 patients presenting with chronic ankle instability (CAI), ankle OA, or other ankle conditions. The association between CFL injuries on the oblique view of MRI and the severity of ankle OA (based on Takakura-Tanaka classification) was statistically evaluated. Additionally, 71 ankles were further subjected to CT evaluation to determine the association between the CFL injuries and the Hounsfield unit (HU) ratios of the subtalar joint and medial gutter, and the correlation between the subtalar HU ratios and osteophyte severity were statistically evaluated. RESULTS: CFL injury was observed in 35.9% (14/39) of patients with stage 0, 42.9% (9/21) with stage 1, 50.0% (10/20) with stage 2, 100% (9/9) with stage 3a, and 90.9% (10/11) with stage 3b. CFL-injured ankles exhibited higher HU ratios in the medial gutter and lower ratios in the medial posterior subtalar joint compared to uninjured ankles. A negative correlation was observed between medial osteophyte severity and the medial subtalar joint HU ratio. CONCLUSION: Our findings suggest that CFL injuries are common in severe ankle OA impairing the compensatory function of the subtalar joint through abnormal stress distribution and osteophyte formation. LEVEL OF EVIDENCE: Level III, retrospective cohort study.
ABSTRACT
We analyzed the intraoperative kinematics of total knee arthroplasty (TKA) using a navigation system to investigate the influence of different inserts on kinematics. This was a retrospective observational study. The Vanguard individualized design (33 patients, 33 knees) XP and anterior-stabilized (AS) inserts were used in TKA for osteoarthritis. Kinematic data were intraoperatively recorded. The range of motion, tibiofemoral rotational angle, anteroposterior translation of the femur, and varus-valgus laxity were compared between the two inserts (XP vs. AS). There was no significant difference in the range of motion (extension: XP, 3.7° ± 3.3° vs. AS, 3.8° ± 3.3°, p = 0.84; flexion: XP, 138.1° ± 10.2° vs. AS, 139.0° ± 13.3°, p = 0.73). With the AS insert, the tibia was gradually internally rotated as the knee was flexed. At maximum extension, the internal rotation was smallest with AS (XP 6.5° ± 4.0° vs. AS 5.1° ± 3.4°, p = 0.022), which was also associated with smaller anterior femoral translation (maximum extension: XP, 14.1 ± 4.8 mm vs. AS, 11.3 ± 4.7 mm, p = 0.00036; 30°: XP, 23.7 ± 5.6 mm vs. AS, 20.7 ± 5.1 mm, p = 0.000033; 45°: XP, 24.4 ± 4.9 mm vs. AS, 23.2 ± 4.5 mm, p = 0.0038). The AS was associated with a lower varus-valgus laxity (30° XP 4.1° ± 3.4 vs. AS 3.3° ± 2.7°, p = 0.036; 60°: XP, 3.2° ± 3.0° vs. AS, 2.4° ± 3.3°, p = 0.0089). The AS insert facilitated sequential tibiofemoral rotation with varus-valgus stability in mid-flexion without restricting the range of motion.
