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Study DesignBiomechanical study.PurposeTo investigate the relative stiffness of a new posterior pelvic fixation for unstable vertical fractures of the sacrum.Overview of LiteratureThe reported operative fixation techniques for vertical sacral fractures include iliosacral screw, sacral bar fixations, transiliac plating, and local plate osteosynthesis. Clinical as well as biomechanical studies have demonstrated that these conventional techniques are insufficient to stabilize the vertically unstable sacral fractures.MethodsTo simulate a vertically unstable fractured sacrum, 12 synthetic pelvic models were prepared. In each model, a 5-mm gap was created through the left transforaminal zone (Denis zone II). The pubic symphysis was completely separated and then stabilized using a 3.5-mm reconstruction plate. Four each of the unstable pelvic models were then fixed with two iliosacral screws, a tension band plate, or a transiliac fixation plus one iliosacral screw. The left hemipelvis of these specimens was docked to a rigid base plate and loaded on an S1 endplate by using the Zwick Roell z010 material testing machine. Then, the vertical displacement and coronal tilt of the right hemipelves and the applied force were measured.ResultsThe transiliac fixation plus one iliosacral screw constructions could withstand a force at 5 mm of vertical displacement greater than the two iliosacral screw constructions (p=0.012) and the tension band plate constructions (p=0.003). The tension band plate constructions could withstand a force at 5° of coronal tilt less than the two iliosacral screw constructions (p=0.027) and the transiliac fixation plus one iliosacral screw constructions (p=0.049).ConclusionsThis study proposes the use of transiliac fixation in addition to an iliosacral screw to stabilize vertically unstable sacral fractures. Our biomechanical data demonstrated the superiority of adding transiliac fixation to withstand vertical displacement forces.

Background Medical education in this era has been disturbed by coronavirus disease. Our faculty has quickly adapted the curricula to online formats. The online format seems to be more advantageous in terms of content material and virtual activities, but the results of these adjustments will require subsequent evaluation. The aim of this study was to evaluate medical student expectations of online orthopedics learning that was created based on social constructivism theory. Materials and methods A cross-sectional survey was carried out to assess the fifth-year medical student expectations of our newly developed online orthopedics course during the outbreak. Constructivist Online Learning Environment Survey (COLLES) was applied for evaluating the expectations during orthopedic rotation. The survey contains six aspects based on social constructivist principles: relevance, reflection, interactivity, tutor support, peer support, and interpretation. All students responded to the preferred COLLES before starting the online course, and the actual COLLES was filled out when the online course was completed. Before and after attending the online course, the scores were compared and interpreted to assess student expectations. Results A total of 126 fifth-year medical students studied the online orthopedic course. The preferred COLLES were completed by 125 students, while 120 students replied to the actual COLLES. The overall scores from the post-course survey in all aspects were significantly higher than scores from the pre-course with P -value < 0.01. The comparison between the preferred and actual scores showed this online course fulfilled student expectations. Conclusion The outbreak of coronavirus disease 19 has disrupted medical student education. The online orthopedic learning course in our department has been developed to deal with the current situation. Using the various activities based on social constructivism theory in the online platform was able to fulfill medical student expectations.

Tuberculous tenosynovitis of hand and wrist is a rare disease but it is found sometimes, especially in TB-endemic areas. The clinical presentation is not specific, however, most patients present with painless swelling at the wrist and hand with limited range of motion, and nerve compression symptoms have been reported. The diagnosis of this conditions can be made from histopathology. Antituberculosis drugs are the mainstay treatment while surgery is controversial. Case presentation We present the case of an 83-year-old Thai woman with no history of exposure to tuberculosis. She presented with swelling and mild pain at her right wrist and the fifth finger of her right hand for 3 months. Ultrasonography revealed tenosynovitis in the right hand and wrist. Mycobacterium tuberculosis was confirmed with tissue diagnosis after an open biopsy. 2-months regimens containing Isoniazid, Rifampicin, Pyrazinamide and Ethambutol/6-months of isoniazid and rifampicin treatment was successful without complications. We follower her up for 1 year, at which time she had returned to do normal daily activities. Her final DASH score was 10.8. Conclusion Tuberculous tenosynovitis is rare, but still occasionally encountered, especially in TB-endemic areas. The challenge is that this condition is difficult to diagnose due to its clinically insidious onset and the presentation is not obviously specific. Laboratory analysis, imaging (MRI, ultrasonography) and microbiology are useful to help reach a diagnosis, but finally confirmation is from histopathology. The treatment mainstay is medical, but surgery may be required if conservative treatment fails or in late stages of the disease.

Identification of the radial nerve is important during the posterior approach to a humerus fracture. During this procedure, the patient can be placed in the prone or lateral decubitus position depending on the surgeon’s preference. The distance from the radial nerve to the osseous structures will be different in each position. The purpose of this study was to identify the safety zones of the various patient and elbow flexion positions. The distances from the olecranon to the center of the radial groove and intermuscular septum and lateral epicondyle to the lateral intermuscular septum were measured using a digital Vernier caliper. The measurements were performed with the cadavers in the lateral decubitus and prone positions with different elbow flexions. The distance from where the radial nerve crossed the posterior aspect of the humerus measured from the upper part of the olecranon to the center of the radial nerve in both positions with different elbow flexion angles varied from a mean maximum distance of 130.00 mm with the elbow in full extension in the prone position to the shortest distance of 121.01 mm with elbow flexion of 120 degree in the lateral decubitus position. The mean distance of the radial nerve from the upper olecranon to the lateral intermuscular septum varied from 107.13 mm to 102.22 mm. The distance from the lateral epicondyle to the lateral edge of the radial nerve varied from 119.92 mm to 125.38 mm. There was very little change in the measurements and no important different distances of radial nerve location until the elbow was flexed to 120 degrees, which was not significant as this flexion is rarely used.

Background: The axillary nerve is at risk for iatrogenic injuries in surgical procedures involving the lateral aspect of the shoulder joint. To date and to our knowledge, there have been no studies that have compared the relevant distances in the common arm abduction positions used in these types of surgery as well as the relative risks of each position. Purpose: To evaluate the effect of arm abduction position on the distance from the acromion process to the axillary nerve in the common abducted arm positions. Study Design: Descriptive laboratory study. Methods: The shoulders of 10 fresh-frozen, full-body cadaveric specimens were used. A saber incision was made at the anterolateral edge of the acromion, and the anterior branch of the axillary nerve was identified. The distance between the anterolateral edge of the acromion process and the axillary nerve was measured 3 times in each of 4 positions: with the arm at the side as well as at 30°, 60°, and 90° of abduction. Then, the same procedure was performed from the midlateral and the posterolateral edges of the acromion process. The distances of the acromion process to the axillary nerve in the 4 positions were compared using 2-way analysis of variance. Results: The mean distances from the anterolateral edge of the acromion process to the anterior branch of the axillary nerve were 52.76 ± 4.64 mm with the arm at the side, 49.48 ± 4.77 mm at 30° of abduction, 46.00 ± 4.75 mm at 60° of abduction, and 42.88 ± 4.59 mm at 90° of abduction. There was a significant decrease in the distance from the anterolateral edge of the acromion process to the axillary nerve as the abduction angle of the arm increased from 0° to 60°, 0° to 90°, and 30° to 90° ( P < .05). Conclusion: The distances from the acromion process to the axillary nerve were shorter in all abducted arm positions than with the arm at the side. Clinical Relevance: To avoid iatrogenic axillary nerve injuries, surgeons should be aware of the safe zone based on the shortest distance from the acromion process to the axillary nerve to ensure no accidental damage to this structure instead of using the mean distance of 5 cm.

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Tuberculosis (TB) infections of the musculoskeletal system are rare. A 77-year-old female with chronic left elbow pain for five months was treated by irrigation and debridement of the elbow for a presumed diagnosis of septic arthritis. Her pain and wound condition did not improve, and she was referred to our institution. Plain radiograph and magnetic resonance imaging (MRI) revealed an osteolytic lesion with joint effusion and severe destruction of the elbow joint. We suspected an atypical infection of the elbow due to the chronicity, negative culture results and severe osteoarticular destruction. An open arthrotomy with irrigation and debridement was performed, and the joint was stabilized with a pin and immobilized. A tissue acid-fast bacillus (AFB) stain was positive and Mycobacterium tuberculosis culture and polymerase chain reaction (PCR) were also positive. Anti-TB drugs were started for a planned 12-month course, but she developed an adverse drug reaction from the standard regimen and had to be switched to a second-line regimen. The stitches were removed at two weeks and the wound eventually healed. The elbow was immobilized in a posterior slab for six weeks then the pin was removed. At the last follow-up visit seven months after the initial surgery, she had improved, with only mild pain on elbow motion. Her range of motion was 110 degrees of flexion and extension lag of 30 degrees. TB of the elbow is a rare condition. The presentation is insidious and varies, and can be confused with other elbow conditions. Delayed diagnosis can lead to severe joint destruction and poor outcome. The physician should always suspect a TB elbow in cases of chronic elbow pain with synovitis, especially in areas endemic for TB. Joint fluid aspiration and MRI are the most reliable investigations for diagnosis. Anti-TB drugs are the mainstay of treatment. Appropriate surgical interventions such as drainage, synovectomy and reconstructive procedures will often be required. Collaboration between the orthopedist and an infectious specialist is essential for optimal treatment planning.