Wood-Splitter-Related Upper-Limb Injuries: A Single-Centered Case-Series Study.

(1) Background: Injuries to the upper limbs during wood splitting can affect social and economic life. We aimed to describe the clinical information concerning these injuries in Japan. (2) Methods: We identified patients from our patient database from April 2015-November 2021 and extracted data from their medical records, which includes age, gender, occupation, month, time and location of the injury, diagnosis, duration of hospitalization, ICU admission, treatment interventions including surgery, outcome, and medical costs. (3) Result: Seventeen cases were identified. Most of the patients were male (n = 15), with median age being 68 years old. Regarding the patients' backgrounds, six were apple farmers and three were unemployed. Injuries to the index finger was most common (n = 9), followed by injuries to the thumb in five cases (n = 5). Most of the incidents occurred at home or on the patient's farm estate. No injuries were due to incidents at work. (4) Conclusion: The wood splitter-related injuries required long-term treatment and frequently damaged the thumb, a functionally important digit. All the injuries were sustained during non-occupational use of a wood splitter. Therefore, we suggest that safety training should be provided to prevent traumatic injuries when these products are being sold.

Epidemiology of Dupuytren's Disease in Japanese General Population.

Background: Dupuytren's disease (DD) is well known as a fibromatous disorder of the palmar aponeurosis. Although there is a large body of literature on the etiology of DD in Europe, there have been few studies in Japan. The purpose of our study was to investigate the etiology and risk factors of DD in a large population in Japan. Methods: The subjects were voluntary participants from the 2014 Health Promotion Project, and 1,112 individuals were included (421 men and 691 women; mean age = 54.2 ± 15.3 years) in this study. The severity of DD was assessed using the Meyerding classification. All participants completed a questionnaire on age, sex, lifestyle, and occupations. All participants also completed the Short Form Health Survey (SF-36) to investigate the QOL. Fasting venous blood specimens were taken for biochemical analysis. Results: DD was found in 44 participants (3.9%). The prevalence was 8.3% among the men and 1.3% among the women. The prevalence in these older than 60 years was 7.7% (men; 18.5%, women; 2.4%). There were 17 participants that had DD of both hands. Multiple digits were affected in 9 participants. The ring finger was the most affected finger (71.2%), followed by the little finger (16.4%), and middle finger (12.3%). In Meyerding classification, 39 cases were stage 0, one case was stage 1, and four cases were stage 2. The multivariate logistic regression analysis revealed that age, sex, smoking, and occupation were significantly associated with DD. There was no significant association between DD and other parameters. When associations between DD and the SF-36 subscales were analyzed, there were significant associations with physical functioning, physical role functioning, and mental health. Conclusions: Our study is the largest in Japan to date. These results will provide very useful data to aid understanding of DD.

Association Between Osteochondritis Dissecans of the Humeral Capitellum and Medial Epicondyle Lesion in Baseball Players.

BACKGROUND: Osteochondritis dissecans (OCD) of the humeral capitellum occurs in adolescent overhead athletes, and medial epicondyle (ME) lesions are also common in this population. PURPOSE: To evaluate the association between elbow OCD and ME lesions in adolescent baseball players. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: This study retrospectively evaluated adolescent baseball players with unstable elbow OCD who underwent surgery between January 2000 and February 2020. Patients were excluded if they had osteoarthritis of the elbow. A total of 139 elbows were included in this study (138 male and 1 female athlete; mean ± SD age, 13.6 ± 1.5 years). The patients were first divided into 2 groups based on OCD location: a central lesion group (72 elbows) and a lateral group (67 elbows). Next, patients were divided according to OCD size into a localized group (56 elbows) and a widespread group (83 elbows). Finally, OCD lesions that were both lateral and widespread were defined as lateral-widespread (60 elbows), resulting in 5 groups. ME apophyseal fragmentation and elongation were evaluated and defined as ME lesions. We then compared the relationship between OCD and ME lesions. RESULTS: Of the 139 elbows, 63 (45.3%) had ME lesions. The prevalence of ME lesion was higher in the lateral group than the central group (56.7% vs 34.7%; P = .009) and higher in the widespread group than the localized group (55.4% vs 30.4%; P = .004). Furthermore, the prevalence ratio of ME lesion was significantly higher in the lateral-widespread group than for other lesions (58.3% vs 35.4%; P = .007). CONCLUSION: In patients undergoing surgery for capitellar OCD, the presence of ME lesions was more commonly associated with lateral and widespread capitellar lesions when compared with central and localized lesions.

Role of MDA5 in regulating CXCL10 expression induced by TLR3 signaling in human rheumatoid fibroblast-like synoviocytes.

C-X-C motif chemokine 10 (CXCL10) is an inflammatory chemokine and a key molecule in the pathogenesis of rheumatoid arthritis (RA). Melanoma differentiation-associated gene 5 (MDA5) is an RNA helicase that plays a role in innate immune and inflammatory reactions. The details of the regulatory mechanisms of CXCL10 production and the precise role of MDA5 in RA synovitis have not been fully elucidated. The aim of this study was to examine the role of MDA5 in regulating CXCL10 expression in cultured human rheumatoid fibroblast-like synoviocytes (RFLS). RFLS was stimulated with Toll-like receptor 3 (TLR3) ligand polyinosinic:polycytidylic acid (poly I:C), a synthetic double-stranded RNA mimetic. Expression of interferon beta (IFN-ß), MDA5, and CXCL10 was measured by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blotting, and enzyme-linked immunosorbent assay. A neutralizing antibody of IFN-ß and siRNA-mediated MDA5 knockdown were used to determine the role of these molecules in regulating CXCL10 expression downstream of TLR3 signaling in RFLS. Poly I:C induced IFN-ß, MDA5, and CXCL10 expression in a concentration- and time-dependent manner. IFN-ß neutralizing antibody suppressed the expression of MDA5 and CXCL10, and knockdown of MDA5 decreased a part of CXCL10 expression (p < 0.001). The TLR3/IFN-ß/CXCL10 axis may play a crucial role in the inflammatory responses in RA synovium, and MDA5 may be partially involved in this axis.

Metacarpal Stress Fracture Is Not an Uncommon Condition in Adolescent Racket Athletes.

BACKGROUND: Stress fractures of the metacarpal bones are considered uncommon. We report on 11 adolescent athletes with these stress fractures, successfully treated with cessation of sports activities. Representative case presentation. In case 1, a 15-year-old male tennis player presented with right hand pain of 4-week duration without an acute trauma history. Tenderness existed on palpation along the dorsal and proximal second metacarpal bone. Plain radiographs demonstrated a periosteal reaction on the proximal shaft of the second metacarpal. Racket swinging was suspended. He returned to competitive tennis 2 months after the initial visit and continues to participate without symptoms. In case 2, a 16-year-old male boxer presented with right hand pain of 2-week duration that arose while punching. Acute trauma history was absent. Tenderness existed on palpation over the third metacarpal of the right hand. Plain radiographs demonstrated no periosteal reaction or fracture line. MRI showed a high signal on the third metatarsal bone on fat suppression and a low signal on T2-weighted images. Nonoperative treatment was initiated without external fixation, and punching was suspended. He returned to boxing 1 month after the initial visit without symptoms. CONCLUSIONS: The current case series of metacarpal stress fractures demonstrate that this condition is not as rare as previously reported. Metacarpal stress fractures are generally ignored since the clinical and radiological findings are mostly unclear. If an athlete experiences hand pain without acute onset during sports activities, especially in racket sports, the presence of a metacarpal stress fracture should be assessed by MRI.

Posterior clearance increases the knee extension angle in cruciate retaining type total knee arthroplasty: Intraoperative evaluation using a navigation system.

BACKGROUND: Posterior osteophyte of the femur can impinge on the tibia insert in total knee arthroplasty (TKA). Although osteophyte removal [posterior clearance (PC)] improves the flexion angle, its influence on the gaps and extension angle are unclear. This study investigated the effect of PC on the gaps and range of motion (ROM) using a navigation system, as well as PC's relationship with osteophyte size. METHODS: Twenty-seven knees that underwent cruciate-retaining (CR)-type TKA were examined. Before and after PC, the ROM, hip-knee-ankle (HKA) angle, and flexion and extension gaps were recorded using a navigation system. Osteophyte size was measured in the lateral view in radiographs, and in the sagittal and axial planes of computed tomography (CT) images. The effects of PC on the gaps and ROM were analysed statistically. RESULTS: PC caused the extension gap to increase by 0.7 ± 0.9 mm in the medial (p < 0.001), and 0.9 ± 1.5 mm in the lateral compartment (p = 0.006). The extension angle increased by 4.9 ± 1.6°, flexion angle increased by 6.5 ± 5.0°, and HKA decreased by 0.3°. The increase in extension angle by PC was significantly correlated with the preoperative HKA angle (r = 0.594) and with the osteophyte area in radiographs and CT (r = 0.626 to 0.681). CONCLUSIONS: The extension and flexion gaps increased less than 1 mm in the medial and lateral compartments. PC achieving an additional 5° extension angle could promote full extension in severely deformed knees with a large posterior osteophyte. The extension angle increase by PC was correlated with the preoperative HKA angle and osteophyte size.

Cervical myelopathy due to a solitary osteochondroma: a case report.

INTRODUCTION: Osteochondroma is the most common benign bone tumor. However, the incidence of osteochondroma in the spine is reported to be very rare. CASE DESCRIPTION: This report presents the case of a 57-year-old man who suffered from osteochondroma of the cervical spine. He had bilateral lower extremity pain for 3 years, developing pain of right upper extremity and gait disturbance. Plain radiographic images and computed tomography scans showed bony lesion in right C6/7 foramen and C6 lamina. Magnetic resonance images of whole spine showed severe compression of spinal cord at the C6/7 and spinal canal stenosis at the L3/4 level. First, we performed a surgery of the cervical spine, and removed the tumor covered with the cartilaginous cap. The pathological diagnosis of the tumor was osteochodroma. After the surgery, the symptoms on his right upper extremity improved smoothly. Because the bilateral lower extremity pain remained, a L3/4 partial laminectomy was performed 1 month later, and the symptom improved. At 1 year after his primary operation, we could not find a recurrence of the tumor. CONCLUSIONS: It is very important to perform a complete en bloc resection of the tumor (especially cartilaginous cap) to prevent the recurrence.

Magnesium ring device to restore function of a transected anterior cruciate ligament in the goat stifle joint.

A bioresorbable, mono-crystalline magnesium (Mg) ring device and suture implantation technique were designed to connect the ends of a transected anterior cruciate ligament (ACL) to restabilize the knee and load the ACL to prevent disuse atrophy of its insertion sites and facilitate its healing. To test its application, cadaveric goat stifle joints were evaluated using a robotic/universal force-moment sensor testing system in three states: Intact, ACL-deficient, and after Mg ring repair, at 30°, 60°, and 90° of joint flexion. Under a 67-N anterior tibial load simulating that used in clinical examinations, the corresponding anterior tibial translation (ATT) and in-situ forces in the ACL and medial meniscus for 0 and 100 N of axial compression were obtained and compared with a control group treated with suture repair. In all cases, Mg ring repair reduced the ATT by over 50% compared to the ACL-deficient joint, and in-situ forces in the ACL and medial meniscus were restored to near normal levels, showing significant improvement over suture repair. These findings suggest that Mg ring repair could successfully stabilize the joint and load the ACL immediately after surgery, laying the framework for future in vivo studies to assess its utility for ACL healing. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2001-2008, 2016.

Histological evaluation of low-intensity pulsed ultrasound on osteochondritis dissecans of the humeral capitellum.

BACKGROUND: The clinical use of low-intensity pulsed ultrasound (LIPUS) was recently evaluated in cases of osteochondritis dissecans of the humeral capitellum (elbow OCD). However, the mechanism underlying the effect of LIPUS in elbow OCD is not well understood. The aim of this study was to histopathologically evaluate the effect of LIPUS irradiation on elbow OCD. METHODS: Fifteen patients with elbow OCD were enrolled in this study. All patients were juvenile baseball players (average age, 13.1 years). LIPUS was performed under the same conditions as the fracture treatment for an average length of 15.1 days in the preoperative period in seven patients (LIPUS group). Cylindrical tissue specimens obtained at the time of surgery were stained with hematoxylin and eosin and alcian blue, and were also immunostained to detect type 1 collagen (Col-1), osteopontin (OPN), and Runx2. The state of the cartilage and subchondral bone and expression levels of Col-1, OPN, and Runx2 were evaluated with a semiquantitative grading system by a blinded pathologist. Histological and immunohistological findings in both groups were compared using Fisher's exact test. RESULTS: Both groups showed reparative tissue and cartilaginous metaplasia at the separation level near the subchondral bone; Col-1 was expressed in the reparative tissue. Furthermore, OPN and Runx2 were expressed in the interstitial cells near the separation level. The cartilage and subchondral bone findings in histological evaluations did not differ significantly between the LIPUS and control groups. The distribution of OPN expression levels in the two groups was as follows: Grade 0-LIPUS group, zero patients, and control group, five patients; Grade 1-LIPUS group and control group, two patients each; Grade 2-LIPUS group, five patients and control group, one patient; Grade 3-LIPUS group, one patient and control group, zero patients. OPN expression was significantly higher in the LIPUS group than in the control group (p = 0.04). CONCLUSION: LIPUS stimulation increased the expression levels of OPN in elbow OCD.

Biomechanical evaluation of the quadriceps tendon autograft for anterior cruciate ligament reconstruction: a cadaveric study.

BACKGROUND: Recently, many surgeons have chosen the quadriceps tendon (QT) as an autograft for anterior cruciate ligament (ACL) reconstruction. However, there have not been biomechanical studies that quantitatively evaluated knee function after reconstruction using a QT autograft. PURPOSE: To measure the 6 degrees of freedom knee kinematics and in situ graft forces after reconstruction with a QT autograft compared with a quadrupled semitendinosus and gracilis (QSTG) tendon autograft. STUDY DESIGN: Controlled laboratory study. METHODS: Ten human cadaveric knees (age, 54-64 years) were tested in 3 conditions: (1) intact, (2) ACL deficient, and (3) after ACL reconstruction using a QT or QSTG autograft. With use of a robotic/universal force-moment sensor testing system, knee kinematics and in situ forces in the ACL and autografts were obtained at 5 knee flexion angles under externally applied loads: (1) 134-N anterior tibial load, (2) 134-N anterior tibial load with 200-N axial compression, and (3) 10-N·m valgus and 5-N·m internal tibial torque. RESULTS: Under the anterior tibial load, both autografts restored anterior tibial translation to within 2.5 mm of the intact knee and in situ forces to within 20 N of the intact ACL at 15°, 30°, and 60°. Adding compression did not change these findings. With the combined rotatory load, the anterior tibial translation and graft in situ forces were again not significantly different from the intact ACL. There were no significant differences between the grafts under any experimental condition. CONCLUSION: Reconstruction of the ACL with a QT autograft restored knee function to similar levels as that reconstructed with a QSTG autograft under loads simulating clinical examinations. CLINICAL RELEVANCE: The positive biomechanical results of this cadaveric study lend support to the use of a QT autograft for ACL reconstruction, as it could restore knee function immediately after surgery under applied loads that mimic clinical examinations.

The femoral insertion of the anterior cruciate ligament: discrepancy between macroscopic and histological observations.

PURPOSE: To observe the femoral anterior cruciate ligament (ACL) insertion macroscopically, histologically, and immunohistologically. METHODS: We used 20 embalmed cadaveric knees (mean age, 69.8 ± 5.3 years) for this study. The femoral ACL insertion was observed macroscopically, and areas were measured with digital calipers. The morphology of the ACL insertion was subsequently observed, and the areas were measured histologically and immunohistologically (stained for types I and III collagen). Finally, the macroscopic and microscopic measurements were compared. RESULTS: Macroscopically, in 16 knees, the proximal ACL fibers spread in a fanlike manner on the medial aspect of the lateral femoral condyle and the femoral insertion was oval. The lengths of the long and short axes of the insertion were 17.7 ± 2.7 mm and 4.6 ± 0.7 mm, respectively. Microscopically, the insertion was located just behind the lateral intercondylar ridge (resident's ridge) and could be divided into the direct and indirect insertions. The direct insertion was 5.3 ± 1.1 mm wide and did not continue to the posterior cartilage. The indirect insertion was located behind the direct insertion, and the posterior ACL fiber stained for type I collagen blended into the posterior cartilage on immunohistologic observations. Another bony ridge was found at the posterior margin of the direct insertion. The widths of the direct insertion were similar between microscopic and macroscopic measurements. CONCLUSIONS: The femoral ACL insertion observed macroscopically corresponded to the direct insertion observed microscopically. The posterior portion behind the lateral intercondylar posterior ridge was the indirect insertion microscopically and appeared membrane-like macroscopically. CLINICAL RELEVANCE: Findings from observation of the lateral intercondylar posterior ridge during arthroscopy and consideration of the distance from the posterior cartilage border may contribute to surgeons' decisions about femoral tunnel placement during anatomic ACL reconstruction.

Mechanism of iodide/chloride exchange by pendrin.

We performed an electrophysiological study to investigate ion transport of pendrin and thereby understand the pathogenesis of Pendred syndrome. Using pendrin-transfected COS-7 cells, we could show that pendrin transports both iodide and chloride measured as voltage-dependent inward and outward membrane currents. Chloride in the culture medium, [Cl-]o, was efficiently exchanged with cytoplasmic iodide, [I-]i, under physiological concentrations, indicating that pendrin is important for chloride uptake and iodide efflux. Although exchange of iodide in the medium, [I-]o, with cytoplasmic chloride, [Cl-]i, was observed, a significantly high concentration of iodide (10 mm) was required. In addition, either iodide or chloride was required on both sides of the cell membrane for the anion exchange activity of pendrin, indicating that iodide and chloride activate the exchange activity of pendrin while they are transported. The present study further supports that pendrin is responsible for the iodide efflux in thyroid cells where intracellular iodide concentration is high and that the general function of pendrin in other tissues is to transport chloride through exchange with other anions.

Prognosis of hypercholesterolemic patients taking pravastatin for five years: the Chiba Lipid Intervention Program (CLIP) Study.

The Chiba Lipid Intervention Program (CLIP) Study was designed to clarify the prognosis of Japanese hypercholesterolemic patients taking pravastatin for 5 years. Hypercholesterolemic patients (n = 2,529) with a total cholesterol level > or = 220 mg/dl and without histories of ischemic coronary heart disease and/or cerebral infarction were administered pravastatin (10-20 mg/day). Among them, 2,131 took pravastatin fully (Pravastatin-continued group), and 398 discontinued the treatment (Discontinued group). The baseline total cholesterol level was 264.3 +/- 34.7 mg/dl (mean +/- standard deviation). The mean reduction rates of total cholesterol and low-density lipoprotein (LDL) cholesterol were 18.0% and 27.2%, respectively. Mild and moderate adverse events occurred in 86 cases (3.6%). Serious adverse events were not observed. Death rates of the pravastatin-continued group and of the discontinued group were 2.6 and 16.0/1,000 persons/year, respectively. Cardiac events (fatal and nonfatal myocardial infarction, cardiac death, angina pectoris) in all, occurred in 35 patients (incidence rate = 2.77/1,000 persons/year). In the pravastatin continued group, 9 causes of fatal and nonfatal myocardial infarction occurred (0.84/1,000 persons/year), whereas in the discontinued group, 4 cases occurred (2.06/1,000 persons/ year). The risk ratio for cardiac events was correlated with the number of risks. In the low-risk group (< or = 1 risk), decreased rates of LDL-cholesterol were less in the cardiac event group than the non-cardiac event group (LDL-cholesterol; 16% vs 25%, p = 0.04). These results suggested the following; 1) Pravastatin maintained a cholesterol lowering effect long-term without serious complications. 2) Pravastatin administration might reduce the mortality rate and myocardial infarction. 3) The combination of multiple risks is a strong factor for a cardiac event in addition to hypercholesterolemia.