• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.29 no.2
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• pp.69-75
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• 2023

Purpose: This study examined the distance between the coracoid process and the humeral head using an ultrasonography device when shoulder active contraction were applied according to the guided direction in the end range of shoulder mobilization. This study aims to provide essential data on treating shoulder disease patients. Methods: The subjects of this study were 20 adults with healthy shoulder joints. ultrasonography (US) equipment was used to examine shoulder joint mobilization under two conditions: (1) anteroposterior (AP) joint mobilization and (2) superoinferior (SI) joint mobilization. Shoulder active contraction was assessed in the end range. The distance between the coracoid process and the humeral head was measured. A linear probe was used for US; the frequency was set to 7.5MHz, and the US image display method was set to B-mode. The US measurement values were measured in (1) the starting position, (2) the end range position, and (3) the end range position of the shoulder active contraction, and the moving distance was drawn in a straight line through the US image. The distance was determined as the measurement value, and the average values were compared. Reults: The results were as follows: (1) the measured AP Joint mobilization increased by an average of .52cm from the end range of the joint mobilization with shoulder active contraction; (2) the measured SI Joint mobilization increased by an average of .49cm from the end range of the joint. Conclusion: When shoulder mobilization is applied, the distance between the coracoid process and the humeral head increases when muscle contraction occurs through shoulder active contraction in the end range, according to the therapist's guidance. Therefore, shoulder mobilization combined with shoulder active contraction is an effective treatment method for patients with shoulder injuries.

• Physical Therapy Korea
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• v.31 no.1
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• pp.72-78
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• 2024

Background: Limitations of shoulder range of motion (ROM), particularly shoulder internal rotation (SIR), are commonly associated with musculoskeletal disorders in both the general population and athletes. The limitation can result in connective tissue lesions such as superior labrum tears and symptoms such as rotator cuff tears and shoulder impingement syndrome. Maintaining the center of rotation of the glenohumeral joint during SIR can be challenging due to the compensatory scapulothoracic movement and anterior displacement of the humeral head. Therefore, observing the path of the instantaneous center of rotation (PICR) using the olecranon as a marker during SIR may provide valuable insights into understanding the dynamics of the shoulder joint. Objects: The aim of the study was to compare the displacement of the olecranon to measure the rotation control of the humeral head during SIR in individuals with and without restricted SIR ROM. Methods: Twenty-four participants with and without restricted SIR ROM participated in this study. The displacement of olecranon was measured during the shoulder internal rotation control test (SIRCT) using a Kinovea (ver. 0.8.15, Kinovea), the 2-dimensional marker tracking analysis system. An independent t-test was used to compare the horizontal and vertical displacement of the olecranon marker between individuals with and without restricted SIR ROM. The statistical significance was set at p < 0.05. Results: Vertical displacement of the olecranon was significantly greater in the restricted SIR group than in the control group (p < 0.05). However, no significant difference was observed in the horizontal displacement of the olecranon (p > 0.05). Conclusion: The findings of this study indicated that individuals with restricted SIR ROM had significantly greater vertical displacement of the olecranon. The results suggest that the limitation of SIR ROM may lead to difficulty in rotation control of the humeral head.

• Clinics in Shoulder and Elbow
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• v.22 no.3
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• pp.121-127
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• 2019

Background: Posterior decentering is not an uncommon finding on rotator cuff tear patients' shoulder magnetic resonance imaging. No previous study has reported on the relationship between posterior decentering and rotator cuff tear. Methods: We assessed patients' rotator cuff tear humeral head positions based on humeral-scapular alignment (HSA). Subjects were classified into centering and decentering groups based on a <2 mm or >2 mm HSA value, respectively. Differences in rotator cuff tear size, degree of tear, and fatty degeneration between the two groups were evaluated. Results: One hundred seventy-five patients (80 males, 95 females; mean age: $59.7{\pm}6.5$ years old) were selected as subjects (casecontrol study; level of evidence: 3). Tear size, degree of subscapularis tendon tear, and fatty degeneration of the supraspinatus, infraspinatus, and subscapularis muscles were significantly different between the two groups (p<0.001, p<0.001, p<0.001). Conclusions: The occurrence of decentering was related to rotator cuff tear size, degree of subscapularis tendon tear, and fatty degeneration of the rotator cuff muscles.

• Clinics in Shoulder and Elbow
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• v.25 no.4
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• pp.282-287
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• 2022

Background: Muscular forces drive proximal humeral fracture deformity, yet it is unknown if arm position can help mitigate such forces. Our hypothesis was that glenohumeral abduction and humeral internal rotation decrease the pull of the supraspinatus and subscapularis muscles, minimizing varus fracture deformity. Methods: A medial wedge osteotomy was performed in eight cadaveric shoulders to simulate a two-part fracture. The specimens were tested on a custom shoulder testing system. Humeral head varus was measured following physiologic muscle loading at neutral and 20° humeral internal rotation at both 0° and 20° glenohumeral abduction. Results: There was a significant decrease in varus deformity caused by the subscapularis (p<0.05) at 20° abduction. Significantly increasing humeral internal rotation decreased varus deformity caused by the subscapularis (p<0.05) at both abduction angles and that caused by the supraspinatus (p<0.05) and infraspinatus (p<0.05) at 0° abduction only. Conclusions: Postoperative shoulder abduction and internal rotation can be protective against varus failure following proximal humeral fracture fixation as these positions decrease tension on the supraspinatus and subscapularis muscles. Use of a resting sling that places the shoulder in this position should be considered.

• Clinics in Shoulder and Elbow
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• v.16 no.2
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• pp.141-147
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• 2013

A 57-year-old man who simultaneously underwent an operation for repair of rotator cuff and a revision operation for nonunion of a Pilon fracture presented with osteomyelitis of the humeral head on the $19^{th}$ day after surgery due to MRSA (Methicillin-resistant Staphylococcus aureus) infection. Infection was controlled after administration of appropriate intravenous antibiotic therapy and performance of several surgical procedures. However, devastating defects at the humeral head and the rotator cuff remained. No case of short term MRSA induced osteomyelitis has been reported.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.171-183
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• 2024

Purpose This study aimed to investigate which indirect parameters on preoperative MRI were the principal predictors of subscapularis tendon tears (STTs) requiring surgical repair. Materials and Methods Preoperative MRI scans of 86 patients were retrospectively reviewed for visual assessment of the STT, pathology of the long head of the biceps tendon (LHBT), posterior decentering (PD) of the humeral head, humeral rotation, fatty degeneration, and subscapularis muscle atrophy. To evaluate atrophy, visual grading using the anatomical line connecting the coracoid tip to the glenoid base, designated as the base-to-tip line (BTL), and thickness measurements were performed in the en-face view. Results Arthroscopically, 31 patients (36%) exhibited Lafosse type III or IV STT and underwent surgical repair. LHBT pathology (p = 0.002), PD of the humeral head (p = 0.012), fatty degeneration (p < 0.001), and BTL grade (p = 0.003) significantly correlated with STT. In the multivariate analysis, PD of the humeral head (p = 0.011, odds ratio [OR] = 5.14) and fatty degeneration (p = 0.046, OR = 2.81) were independent predictors of STT. Conclusion PD of the humeral head and fatty degeneration of the subscapularis can help to diagnose clinically significant STT. Interpretation of these findings may contribute to the planning of an optimal surgical strategy.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.44-44
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• 2009

The purpose of this study was to investigate humeral translation relative to the glenoid invivo during loaded and unloaded shoulder abduction. CT scans of 9 healthy shoulders were acquired and 3D models were created. The subject was positioned in front of a fluoroscope and motions were recorded during active abduction. The subjects performed two trials of holding a 3kg weight and unload. 3D motions were determined using model-based 3D-to-2D registration to obtain 6 degrees of freedom kinematics. Glenohumeral translation was determined by finding the location on the humeral head with the smallest separation from the glenoid. Humeral translation was referenced to the glenoid center in the superior/inferior direction. The humerus moved an average of 2 mm, from inferior to central on the glenoid, during arm abduction for both conditions. The humeral head was centered within 1mm from the glenoid center above $70^{\circ}$. There were no statistically significant differences for both conditions. The standard deviation decreased gradually over the motion, with significantly lower variability at the end of abduction compared to the initial unloaded position. We assumed that the humeral translation to the center of the glenoid provides maximum joint congruency for optimal shoulder function and joint longevity. We believe this information will lead to better strategies to prevent shoulder injuries, enhance rehabilitation, and improve surgical treatments.

• Clinics in Shoulder and Elbow
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• v.2 no.2
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• pp.151-156
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• 1999

Purpose : Average humeral head retroversion was showed significant wide range from literatures based on variable measuring technique, We performed computed tomography(CT) study in an effort to define the specific anatomy relationships and evaluate their use. Materials and Methods : Two hundreds shoulders and distal humeri CT scan with no known pathology were examined. The study population was divided to 10 groups by gender and age (from third to seventh decade). The number of each group was twenty. Retroversion of proximal humerus and glenoid were measured using the lines that were connected the central axis of humeral head, central points of the humeral epicondyles paralleling to the trochlea, paralled to the glenoid surface, midpoint between the transverse glenoid diameter and medial edge of the scapular. We also measured the bicipital groove distance from the humeral central axis and scapulothoracic angle. Results: Retroversion of proximal humerus was highly variable, ranging in this study from 13 to 58 degrees(mean 28.73) These values correlated with sex, not age, height or hand dominance. Glenoid retroversion at the inferior sections showed average 1.3 degree, did not signigicant differences. The central axis was an average of l0mm(5-15mm) posterior to the posterior margin of the bicipital groove. Scapulothoracic angle was average 43 degrees(25-53 degrees) Conclusion: Anatomical reconstruction of retroversion angle should be individualized and bicipital groove could be useful as landmark for the lateral fin of the prosthesis to be positioned an average of 10mm posteriorly.

• Clinics in Shoulder and Elbow
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• v.21 no.4
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• pp.220-226
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• 2018

Background: This study introduces a surgical technique with good clinical outcome useful in the treatment of osteoporotic displaced 3- or 4-part proximal humeral fractures. Methods: From May 2014 to February 2016, 16 patients with displaced 3- or 4-part proximal humeral fractures were treated by application of a locking plate with an endosteal strut allograft via a deltoid splitting approach with a minimum follow-up of 12 months. The allograft was inserted through a fractured gap of the greater tuberosity to support the humeral head and then fixed by a locking plate with meticulous soft tissue dissection to protect the axillary nerve. Surgical outcomes were evaluated by the American Shoulder and Elbow Surgeons (ASES) and visual analogue scale (VAS) scores, radiological imaging, and clinical examination. Fixation failure on radiographs was defined as a >$5^{\circ}$ loss of neck shaft angle (NSA) compared to that on an immediate postoperative radiograph. Avascular necrosis (AVN) of the humeral head was also evaluated. Results: In all cases, complete union was achieved. The ASES and VAS scores were improved to $85.4{\pm}2.1$ and $3.2{\pm}1.3$, respectively. Twelve patients (75.0%) had greater than a $5^{\circ}$ change in NSA; the average NSA change was $3.8^{\circ}$. Five patients (31.3%) had unsatisfactory ranges of motion exhibiting a <$100^{\circ}$ active forward flexion. No axillary nerve injuries or AVN were observed at the last follow-up. One patient was converted to reverse total arthroplasty due to severe pain and functional deficit. Conclusions: Minimally invasive fixation via a locking compression plate and an endosteal fibula strut allograft in Neer classification 3-or 4-part fractures with severe osteoporosis in elderly patients can achieve good clinical results.

• Clinics in Shoulder and Elbow
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• v.22 no.3
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• pp.119-120
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• 2019