Association of dorsal malunion in distal radius fractures with wrist osteoarthritis: Alterations of bone density and stress-distribution patterns in relation to deformation angles.

OBJECTIVE: Distal radius fractures (DRFs) with dorsal malunion increase the risk of osteoarthritis (OA), although the cause of post-DRF OA is yet to be elucidated. To clarify the abnormal effects of a post-DRF dorsal radius deformity, we evaluated the bone density (BD) and stress-distribution patterns of the articular surface in dorsally malunited DRFs. DESIGN: In 36 cases of dorsally malunited DRFs following extra-articular fractures, we generated three-dimensional computerized models of the malunited distal radius from computed tomography data and extracted the subchondral bones of the radiocarpal joint (RCJ) and distal radioulnar joint (DRUJ). Both BD and stress distribution in the subchondral bones were quantitatively evaluated by comparing the affected and normal sides. Correlations of alterations in high-BD distribution and deformation angles were analyzed. RESULTS: The center of high-BD distribution from the center of the RCJ in the volar(-)-dorsal(+) direction was dorsal (0.56 ± 0.72 mm) on the affected side compared with the normal side (-0.15 ± 0.63 mm) [95% CI: 0.43, 1.00, P < 0.0001]. The maximum stress distribution was also dorsal on the affected side (2.34 ± 3.52 mm) compared with the normal side (-2.49 ± 1.62 mm) [95% CI: 0.89, 1.79, P < 0.0001]. The alterations in BD and stress distribution correlated with the dorsiflexion and radial deviation angles. In the DRUJ, there was no significant difference in BD between the affected and normal sides. CONCLUSIONS: In dorsally malunited DRFs, the alignment change of the RCJ resulted in high BD-concentration areas and stress distribution on the dorsal side of the radius, which may constitute a precursor for OA.

Cubitus varus deformity following paediatric supracondylar humeral fracture remodelling predominantly in the sagittal direction: A three-dimensional analysis of eighty-six cases.

PURPOSE: Three-dimensional (3D) capacity for remodelling in cubitus varus deformity (CVD) after paediatric supracondylar humeral fractures (PSHFs) remains unelucidated. This study investigated remodelling patterns after PSHFs by examining 3D deformity distribution over time after injury. METHODS: Computed tomography (CT) data of 86 patients with CVD after PSHFs were analysed. The 3D deformity angles in the sagittal, coronal, and axial directions were assessed and correlated with the duration between the age at injury and CT evaluation. For the subgroup analysis, we performed the same correlation analysis in a younger (< 8 years old) and an older group (≥ 8 years old); we categorized the duration into early (< 2 years), middle (≥ 2 to < 5 years), and late periods (≥ 5 years) and compared the deformity angles of each direction among the three groups. RESULTS: Sagittal deformity showed a moderate correlation with the duration of deformity (r = -0.54; P < 0.001), while coronal and axial deformities showed a negligible correlation. Sagittal deformity showed moderate correlations with the duration in the younger group (r = -0.62; P < 0.001) and weak correlations in the older group (r = -0.37; P = 0.091). In the sagittal direction, the deformity angle in the early period was significantly larger than those in the mid and late periods (P < 0.001). However, there were no significant differences among the three groups in the coronal and axial directions. CONCLUSION: Sagittal deformities in CVDs are capable of remodelling, especially in the early period and at a younger age, whereas coronal and axial deformities are less likely to undergo remodelling.

Reproduction of forearm rotation dynamic using intensity-based biplane 2D-3D registration matching method.

This study aimed to reproduce and analyse the in vivo dynamic rotational motion of the forearm and to clarify forearm motion involvement and the anatomical function of the interosseous membrane (IOM). The dynamic forearm rotational motion of the radius and ulna was analysed in vivo using a novel image-matching method based on fluoroscopic and computed tomography images for intensity-based biplane two-dimensional-three-dimensional registration. Twenty upper limbs from 10 healthy volunteers were included in this study. The mean range of forearm rotation was 150 ± 26° for dominant hands and 151 ± 18° for non-dominant hands, with no significant difference observed between the two. The radius was most proximal to the maximum pronation relative to the ulna, moved distally toward 60% of the rotation range from maximum pronation, and again proximally toward supination. The mean axial translation of the radius relative to the ulna during forearm rotation was 1.8 ± 0.8 and 1.8 ± 0.9 mm for dominant and non-dominant hands, respectively. The lengths of the IOM components, excluding the central band (CB), changed rotation. The transverse CB length was maximal at approximately 50% of the rotation range from maximum pronation. Summarily, this study describes a detailed method for evaluating in vivo dynamic forearm motion and provides valuable insights into forearm kinematics and IOM function.

Ambulance Traffic Crashes in Japan: Characteristics of Casualties and Efforts to Improve Ambulance Safety.

BACKGROUND: An ambulance traffic crash not only leads to injuries among emergency medical service (EMS) professionals but also injures patients or their companions during transportation. We aimed to describe the incidence of ambulance crashes, seating location, seatbelt use for casualties (ie, both fatal and nonfatal injuries), ambulance safety efforts, and to identify factors affecting the number of ambulance crashes in Japan. METHODS: We conducted a nationwide survey of all fire departments in Japan. The survey queried each fire department about the number of ambulance crashes between January 1, 2017, and December 31, 2019, the number of casualties, their locations, and seatbelt usage. Additionally, the survey collected information on fire department characteristics, including the number of ambulance dispatches, and their safety efforts including emergency vehicle operation training and seatbelt policies. We used regression methods including a zero-inflated negative binomial model to identify factors associated with the number of crashes. RESULTS: Among the 726 fire departments in Japan, 553 (76.2%) responded to the survey, reporting a total of 11,901,210 ambulance dispatches with 1,659 ambulance crashes (13.9 for every 100,000 ambulance dispatches) that resulted in a total of 130 casualties during the 3-year study period (1.1 in every 100,000 dispatches). Among the rear cabin occupants, seatbelt use was limited for both EMS professionals (n = 3/29, 10.3%) and patients/companions (n = 3/26, 11.5%). Only 46.7% of the fire departments had an internal policy regarding seatbelt use. About three-fourths of fire departments (76.3%) conducted emergency vehicle operation training internally. The output of the regression model revealed that fire departments that conduct internal emergency vehicle operation training had fewer ambulance crashes compared to those that do not (odds of being an excessive zero -2.20, 95% CI: -3.6 to -0.8). CONCLUSION: Two-thirds of fire departments experienced at least one crash during the study period. The majority of rear cabin occupants who were injured in ambulance crashes were not wearing a seatbelt. Although efforts to ascertain seatbelt compliance were limited, Japanese fire departments have attempted a variety of methods to reduce ambulance crashes including internal emergency vehicle operation training, which was associated with fewer ambulance crashes.

Optimal tentative abdominal closure for open abdomen: a multicenter retrospective observational study (OPTITAC study).

BACKGROUND: Primary fascia closure is often difficult following an open abdomen (OA). While negative-pressure wound therapy (NPWT) is recommended to enhance successful primary fascia closure, the optimal methods and degree of negative pressure remain unclear. This study aimed to elucidate optimal methods of NPWT as a tentative abdominal closure for OA to achieve primary abdominal fascia closure. MATERIALS AND METHODS: A multicenter, retrospective, cohort study of adults who survived OA greater than 48 h was conducted in 12 institutions between 2010 and 2022. The achievement of primary fascia closure and incidence of enteroatmospheric fistula were examined based on methods (homemade, superficial NPWT kit, or open-abdomen kit) or degrees of negative pressure (<50, 50-100, or >100 mmHg). A generalized estimating equation was used to adjust for age, BMI, comorbidities, etiology for laparotomy requiring OA, vital signs, transfusion, severity of critical illness, and institutional characteristics. RESULTS: Of the 279 included patients, 252 achieved primary fascia closure. A higher degree of negative pressure (>100 mmHg) was associated with fewer primary fascia closures than less than 50 mmHg [OR, 0.18 (95% CI: 0.50-0.69), P =0.012] and with more frequent enteroatmospheric fistula [OR, 13.83 (95% CI: 2.30-82.93)]. The methods of NPWT were not associated with successful primary fascia closure. However, the use of the open-abdomen kit was related to a lower incidence of enteroatmospheric fistula [OR, 0.02 (95% CI: 0.00-0.50)]. CONCLUSION: High negative pressure (>100 mmHg) should be avoided in NPWT during tentative abdominal closure for OA.

Arthroscopic Debridement for Refractory Lateral Epicondylitis Results for Substantial Improvement in Tendinosis Scores and Good Clinical Outcomes: Qualitative and Quantitative Magnetic Resonance Imaging Analysis.

PURPOSE: To qualify and quantify the changes in magnetic resonance imaging (MRI) signals in the extensor tendons after arthroscopic debridement for lateral epicondylitis and evaluate the association between MRI findings and temporal clinical results by comparisons between recovered and unrecovered cases. METHODS: Thirty-four patients with refractory lateral epicondylitis treated with arthroscopic debridement were divided into recovered (n = 24) and unrecovered (n = 10) groups according to the Japanese Orthopaedic Association-Japan Elbow Society score. This study included any patients who underwent both the pre- and postoperative MRI and excluded patients with a previous history of any elbow surgery. Pre- and postoperative MRI findings were qualitatively categorized into 4 grades, quantified by measuring the percentage of tendinopathy area, and compared between the groups. RESULTS: Preoperatively, grading scores and percentages did not show significant differences between groups (P = .050 and .519). The respective numbers of patients with grades 1, 2, 3, and 4 were 1 (4%), 3 (13%), 10 (42%), and 10 (42%) in the recovered group; and 1 (10%), 2 (20%), 7 (70%), and 0 (0%) in the unrecovered group. The average percentages in the recovered and unrecovered groups were 42.3% (73.9 mm2/168.4 mm2); and 36.5% (50.5 mm2/131.0 mm2). However, postoperatively, they were significantly lower in the recovered group than in the unrecovered group (P = .007 and .014). The numbers and percentages in the recovered and unrecovered groups were 15 (63%), 8 (33%), 1 (4%), and 0 (0%) and 17.0% (28.6mm2/169.8mm2) and 2 (20%), 3 (30%), 5 (50%), and 0 (0%) and 30.5% (39.0 mm2/131.8 mm2). CONCLUSIONS: Qualitative and quantitative MRI is useful for evaluating the progress of tendon healing after arthroscopic debridement. In the recovered and unrecovered groups, improvement of tendinopathy area were 60% versus 16%, indicating that postoperative MRI findings reflect clinical outcomes. LEVEL OF EVIDENCE: IV, case series with subgroup analysis.

Measurement of nuclear reaction cross sections by using Cherenkov radiation toward high-precision proton therapy.

Monitoring the in vivo dose distribution in proton therapy is desirable for the accurate irradiation of a tumor. Although positron emission tomography (PET) is widely used for confirmation, the obtained distribution of positron emitters produced by the protons does not trace the dose distribution due to the different physical processes. To estimate the accurate dose from the PET image, the cross sections of nuclear reactions that produce positron emitters are important yet far from being sufficient. In this study, we measured the cross sections of 16O(p,x)15O, 16O(p,x)13N, and 16O(p,x)11C with a wide-energy range (approximately 5-70 MeV) by observing the temporal evolution of the Cherenkov radiation emitted from positrons generated via ß+ decay along the proton path. Furthermore, we implemented the new cross sectional data into a conventional Monte Carlo (MC) simulation, so that a direct comparison was possible with the PET measurement. We confirmed that our MC results showed good agreement with the experimental data, both in terms of the spatial distributions and temporal evolutions. Although this is the first attempt at using the Cherenkov radiation in the measurements of nuclear cross sections, the obtained results suggest the method is convenient and widely applicable for high precision proton therapy.