松本 卓巳

OBJECTIVE: Hallux rigidus (HR), a form of osteoarthritis (OA) affecting the first metatarsophalangeal joint, significantly impairs mobility and quality of life. Despite its clinical importance, large-scale epidemiological studies on radiographic HR prevalence and associated factors remain limited. This study investigated the radiographic prevalence of HR and its associated factors in a large, population-based Japanese cohort. DESIGN: Data were obtained from 1998 participants (654 men, 1344 women) in the fifth survey of the nationwide Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study. Non-weight-bearing dorsoplantar foot radiographs were assessed using the Hattrup and Johnson classification (grade 1: mild, grade 2: moderate, and grade 3: severe); HR was defined as grade ≥1. Multivariable logistic regression assessed associated factors, and the Cochran-Armitage trend test evaluated severity-related trends. RESULTS: The mean age was 64.2 ​± ​12.7 years. The overall HR prevalence was 23.5 ​% (25.1 ​% in men, 22.8 ​% in women), with no significant sex difference. Unilateral and bilateral HR were 6.6 ​% and 17.0 ​% of participants, respectively. HR was classified as mild (13.3 ​%), moderate (7.0 ​%), or severe (3.3 ​%). Multivariable analysis identified older age, coastal residence, gout history, and knee OA as independent factors associated with HR. HR severity showed significant linear trends with both gout and knee OA. CONCLUSIONS: This study determined the radiographic prevalence of HR of 23.5 ​% in a Japanese population. Independent factors associated with HR included older age, coastal residence, gout, and knee OA. Findings indicate that HR is multifactorial and highlight the need to explore geographic and lifestyle-related factors in addition to medical conditions.

OBJECTIVE: This study aimed to investigate whether discontinuation of biological or targeted synthetic antirheumatic disease-modifying drugs (bDMARDs or tsDMARDs) influences the incidence of postoperative complications in patients with rheumatoid arthritis (RA) undergoing orthopedic surgery. METHODS: A retrospective multicenter cohort study including patients receiving bDMARDs or tsDMARDs who underwent orthopedic surgery was conducted. Data collected encompassed the duration of drug discontinuation and postoperative adverse events, such as delayed wound healing, surgical site infection (SSI), disease flare-ups, and mortality. The association between drug discontinuation and these outcomes was analyzed. Multivariate analyses were conducted to identify potential risk factors for these events. RESULTS: A total of 2,060 cases were initially enrolled. After applying inclusion and exclusion criteria, data from 1,953 patients were analyzed. No significant differences were observed between the groups regarding delayed wound healing, SSI, or mortality. However, the incidence of disease flare-ups was substantially higher in the drug discontinuation group and in the interleukin (IL)-6 inhibitor group. Multivariate analysis identified that tumor necrosis factor α and IL-6 inhibitor use was associated with a higher risk of delayed wound healing relative to T-cell function modifiers. CONCLUSION: In orthopedic surgery for patients with RA, maintaining the standard or the half of administration interval of bDMARD appears safe in the preoperative period. However, the drug discontinuation may increase the risk of postoperative flare-ups, particularly with IL-6 inhibitors. In addition, T-cell function modifiers may be associated with a lower risk of delayed wound healing, suggesting their safety profile in this context.

OBJECTIVES: This study aimed to reveal the frontal plane relationship between the ground reaction force (GRF), hip center (HC), and Mikulicz line under various standing conditions and during gait. METHODS: A dual-design approach, combining a static experiment and gait-database analysis, was used. First, a static experiment was conducted with 10 healthy adults standing on force plates under five conditions: stance widths of 0, 5, 10, and 20 cm, and single-leg stance. Second, gait data from a public database (n = 162, age ≤50 years) were analyzed to calculate comparable parameters during the single stance phase. The GRF-HC distance and the angle between the GRF and the line through the center of pressure and HC (GRF-Mikulicz angle) were evaluated using analysis of variance. RESULTS: Both the GRF-HC distance and the GRF-Mikulicz angle significantly differed among the bipedal standing conditions, with smallest values at 20 cm (1.3 cm, 0.3°) and largest at 0 cm (7.3 cm, 4.8°). Values at 0 cm did not significantly differ from single-leg standing (8.8 cm, 5.8°), and both fell within the ranges observed during the single stance phase of gait (6.5-9.2 cm, 4.8°-6.7°). CONCLUSION: A 20 cm-stance width best aligns the GRF with Mikulicz line in static standing. Single-leg and closed-leg standing replicate GRF direction during gait. These findings may inform preoperative planning of total knee arthroplasty but require validation in larger and patient-based cohorts, given the small sample size and restriction to healthy subjects. This exploratory study should be interpreted with caution regarding direct clinical application.

BACKGROUND: Achieving precise three-dimensional reconstruction during foot and ankle corrective surgeries is challenging. Intraoperative plantar pressure measurement (IPPM) can help assess foot morphology and detect abnormal pressure distributions. We developed an IPPM system using a navigation to align the floor reaction force with the femoral head's center. This study evaluates its accuracy in anesthetized patients. PATIENTS AND METHODS: Fifteen patients undergoing lower limb surgery were enrolled. Plantar pressure was measured intraoperatively in the supine position and compared with preoperative standing measurements. Similarity was evaluated using normalized cross-correlation (NCC) and peak pressure site agreement across 12 predefined foot regions. RESULTS: The IPPM device replicated standing plantar pressure, with a mean NCC of 0.92 ± 0.1 and a peak pressure site agreement rate of 76.7 ± 37.2 %. CONCLUSIONS: The newly developed intraoperative plantar pressure-measuring device accurately replicates standing plantar pressure in anesthetized patients, offering potential for improving intraoperative assessments and corrective procedures.

BackgroundThe accessory navicular is a common anatomical variant of the foot that may become symptomatic and occasionally require treatment, particularly in younger individuals. Recent evidence indicates that accessory navicular may be associated with posterior tibial tendon dysfunction in middle-aged and elderly individuals, potentially affecting physical function. However, research on its impact in this demographic remains limited. This study aims to assess the epidemiology and impact of accessory navicular, particularly type 2, on physical function in the general population.MethodsData from the fifth Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study were analyzed, including foot radiographs and physical examinations from 1995 participants. The presence and type of accessory navicular were determined, and physical function was assessed through stabilometer measurements, walking speed tests, and locomotive syndrome risk tests. In addition, the relevant items related to balance and falls were extracted from the structured interviews and analyzed for the relationship with the accessory navicular.ResultsThe prevalence of accessory navicular was higher in females (49.9%) than in males (43.2%), with type 2 being the most frequent type. The analysis revealed a high degree of bilateral symmetry, with 79.5% of males and 76.7% of females showing the same type of accessory navicular or absence thereof on both sides. No significant differences were found in physical performance measurements between feet with and without type 2 accessory navicular. Notably, a higher history of falls was associated with bilateral type 2 accessory navicular.ConclusionsThis study provides insights into the prevalence and type distribution of accessory navicular in the general population. While type 2 accessory navicular did not show significant impacts on physical performance, its association with a history of falls suggests potential implications for dynamic balance ability, warranting further investigation.Levels of Evidence:Level III retrospective case-control study.