藤田 順之

An absorbable adhesion barrier is a medical device that prevents postoperative adhesion and matches its biodegradation time with the regeneration period of its target tissues, which is important for antiadhesion effects. Physical hydrogels of Bombyx mori silk fibroin (SF) proteins are degradable in vivo. However, their biodegradation time is too long to exert antiadhesion effects. To shorten the biodegradation time of the SF hydrogels, we decreased the molecular weight (MW) of the SF proteins by alkaline treatment and prepared low-MW (LMW) SF hydrogels. The hydrogels contained less β-sheet crystalline and more amorphous structures than conventional, high-MW (HMW) SF hydrogels. Because of the potential loosened SF molecular structures in the hydrogel networks, the LMW SF hydrogels showed enhanced biodegradation (i.e., shorter in vitro enzymatic biodegradation time and faster in vivo biodegradation rate) as well as a lower affinity for plasma proteins and fibroblasts, which are involved in postoperative adhesion formation. An antiadhesion test using a rat abdominal adhesion model demonstrated that the LMW SF hydrogel applied to the abraded cecum was almost completely degraded within two weeks postimplantation, with a significantly lower adhesion severity score than that in the untreated model rat group. Conversely, the HMW SF hydrogel remained between the cecum and abdominal wall, with the same adhesion severity as that of the untreated model rat group. Therefore, we concluded that the antiadhesion effects of SF hydrogels were induced by enhanced biodegradation. The results of this study indicate the potential of LMW SF hydrogels as absorbable adhesion barriers.

PURPOSE: The purpose of this study was to determine the capability of proton density with fat fraction (PD-FFQ) imaging to help assess hematopoietic ability and diagnose aplastic anemia in adults. METHODS: Between January 2021 and March 2023, patients diagnosed with aplastic anemia (AA: n = 14) or myelodysplastic syndrome (MDS: n = 14) were examined by whole-body PD-FFQ imaging, and 14 of 126 age and gender matched patients who had undergone the same PD-FFQ imaging were selected as control group. All proton density fat fraction (PDFF) index evaluations were then performed by using regions of interest (ROIs). Pearson's correlation was used to determine the relationship between blood test results and each quantitative index, and ROC-based positive test and discrimination analyses to compare capability to differentiate the AA from the non-AA group. Finally, sensitivity, specificity and accuracy of all quantitative indexes were compared by means of McNemar's test. RESULTS: Mean PDFF, standard deviation (SD) and percentage of coefficient of variation (%CV) for vertebrae showed significant correlation with blood test results (-0.52 ≤ r ≤ -0.34, p < 0.05). Specificity (SP) and accuracy (AC) of %CV of PDFF in vertebrae were significantly higher than those of mean PDFF in vertebrae and the posterior superior iliac spine (SP: p = 0.0002, AC: p = 0.0001) and SD of PDFF in vertebrae (SP: p = 0.008, AC: p = 0.008). Moreover, AC of SD of PDFF in vertebrae was significantly higher than that of mean PDFF in vertebrae and the posterior superior iliac spine (p = 0.03). CONCLUSION: Whole-body PD-FFQ imaging is useful for hematopoietic ability assessment and diagnosis of aplastic anemia in adults.

INTRODUCTION AND IMPORTANCE: Synovial osteochondromatosis of the shoulder joint is predominantly primary, characterized by multiple osteochondral fragments, with reports of secondary synovial osteochondromatosis being rare. CASE PRESENTATION: The patient, a 48-year-old male, presented to our hospital with right shoulder pain persisting for several months. While there was no significant restriction in the range of motion, pain was noted during horizontal adduction and external rotation in the dependent position. Radiographs and CT scans revealed an osteochondral loose body in the glenohumeral joint and an osteophyte on the anterior margin of the glenoid cavity. A lidocaine test in the glenohumeral joint was positive, suggesting impingement by the loose body, leading to its surgical removal. Arthroscopically, the loose body was grasped and removed from the anterior aspect of the glenohumeral joint. The osteochondral fragment measured approximately 15 mm, with the total length including soft tissue being about 40 mm. Pathological findings indicated a layered arrangement of synovial cells, consistent with secondary synovial osteochondromatosis. Postoperatively, the shoulder pain improved rapidly, and follow-up was concluded six months after surgery. CLINICAL DISCUSSION: In this case, arthroscopy revealed a Hill-Sachs-like lesion and labral deficiency on the glenoid, suggesting past trauma. However, no bone defect matching the size of the loose body was observed. In secondary synovial osteochondromatosis, small osteochondral fragments can grow with nourishment from the synovium, suggesting the loose body in this case might have similarly enlarged post-trauma. CONCLUSION: The shoulder pain caused by a giant secondary synovial osteochondromatosis improved by removing the loose body arthroscopically.

AIM: Older patients with lumbar spinal stenosis (LSS) have a higher incidence of polypharmacy attributed to comorbidities and the use of pain relief medications. This study aimed to explore the effect of polypharmacy and hyperpolypharmacy on surgical outcomes in older patients with LSS based on health-related quality of life (HRQOL) and locomotive syndrome. METHODS: Consecutive patients aged ≥65 years who underwent lumbar spinal surgery for LSS were retrospectively reviewed. We assessed the preoperative and 1- and 2-year postoperative scores of three common HRQOL tools and the 25-question Geriatric Locomotive Function Scale. The patients were classified into the hyperpolypharmacy group (those taking ≥10 medications), polypharmacy group (those taking 6-9 medications) and non-polypharmacy group (those taking ≤5 medications). RESULTS: In total, 148 participants were evaluated. Among them, 35 were included in the non-polypharmacy group. There were no significant changes in the HRQOL and locomotive syndrome stage at baseline, even with polypharmacy progression. However, the HRQOL and locomotive syndrome stage worsened postoperatively with polypharmacy progression. When surgical efficacy was directly examined, results showed that the surgical outcomes were significantly associated with polypharmacy progression in older patients with LSS, even after adjusting for potential confounders. CONCLUSIONS: Polypharmacy, especially hyperpolypharmacy, had a negative impact on surgical outcomes in older patients with LSS. The number of prescription drugs should be taken into consideration before surgery in this patient group. Geriatr Gerontol Int 2024; ••: ••-••.

INTRODUCTION/AIMS: T2 magnetic resonance imaging (MRI) mapping has been applied to carpal tunnel syndrome (CTS) for quantitative assessment of the median nerve. However, quantitative changes in the median nerve before and after surgery using T2 MRI mapping remain unclear. We aimed to investigate whether pathological changes could be identified by pre- and postoperative T2 MRI mapping of the median nerve in CTS patients after open carpal tunnel release. METHODS: This was a prospective study that measured median nerve T2 and cross-sectional area (CSA) values at the distal carpal tunnel, hamate bone, proximal carpal tunnel, and forearm levels pre- and postoperatively. Associations between T2, CSA, and nerve conduction latency were also evaluated. RESULTS: A total of 36 patients with CTS (mean age, 64.5 ± 11.7 years) who underwent surgery were studied. The mean preoperative T2 values significantly decreased from 56.3 to 46.9 ms at the proximal carpal tunnel levels (p = .001), and from 52.4 to 48.7 ms at the hamate levels postoperatively (p = .04). Although there was a moderate association between preoperative T2 values at the distal carpal tunnel levels and distal motor latency values (r = -.46), other T2 values at all four carpal tunnel levels were not significantly associated with CSA or nerve conduction latency pre- or postoperatively. DISCUSSION: T2 MRI mapping of the carpal tunnel suggested a decrease in nerve edema after surgery. T2 MRI mapping provides quantitative information on the median nerve before and after surgery.