• Clinics in Shoulder and Elbow
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• v.26 no.2
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• pp.131-139
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• 2023

Background: Massive rotator cuff tears (RCTs) are complicated by muscle atrophy, fibrosis, and intramuscular fatty degeneration, which are associated with postoperative tendon-to-bone healing failure and poor clinical outcomes. We evaluated muscle and enthesis changes in large tears with or without suprascapular nerve (SN) injury in a rat model. Methods: Sixty-two adult Sprague-Dawley rats were divided into SN injury (+) and SN injury (-) groups (n=31 each), comprising tendon (supraspinatus [SSP]/infraspinatus [ISP]) and nerve resection and tendon resection only cases, respectively. Muscle weight measurement, histological evaluation, and biomechanical testing were performed 4, 8, and 12 weeks postoperatively. Ultrastructural analysis with block face imaging was performed 8 weeks postoperatively. Results: SSP/ISP muscles in the SN injury (+) group appeared atrophic, with increased fatty tissue and decreased muscle weight, compared to those in the control and SN injury (-) groups. Immunoreactivity was only positive in the SN injury (+) group. Myofibril arrangement irregularity and mitochondrial swelling severity, along with number of fatty cells, were higher in the SN injury (+) group than in the SN injury (-) group. The bone-tendon junction enthesis was firm in the SN injury (-) group; this was atrophic and thinner in the SN injury (+) group, with decreased cell density and immature fibrocartilage. Mechanically, the tendon-bone insertion was significantly weaker in the SN injury (+) group than in the control and SN injury (+) groups. Conclusions: In clinical settings, SN injury may cause severe fatty changes and inhibition of postoperative tendon healing in large RCTs. Level of evidence: Level Basic research, controlled laboratory study.

• Clinical Pain
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• v.19 no.2
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• pp.59-63
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• 2020

Rotator cuff tear is often cited as a reason for shoulder pain and dysfunction in patients > 40 years of age. Surgical repair of rotator cuff tear is one of the most commonly performed orthopedic surgical procedures. Until now, the success rate of surgical repair for rotator cuff tear has not been satisfactory. Many factors influence the process of rotator cuff repair such as the presence of tendinosis and fatty infiltration, but the main factor is the difficulty in achieving healing at the tendon to bone interface. There is a clinical need for bioengineering approaches to promote regeneration of the native enthesis and reduce the poor outcomes after surgical repair. Toward this end, the design and fabrication of multiphasic or hierarchically structured scaffolds have received great attention. This manuscript deals with information on the tendon to bone interface and tries to find out why a multiphasic scaffold is necessary to reproduce it and considerations that need to be taken into to make an ideal scaffold.

• Journal of Korean Foot and Ankle Society
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• v.10 no.1
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• pp.113-116
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• 2006

Benign and malignant tumors are found in the foot, although the incidence is low. The most common bone tumor in the foot is osteochondroma, which is thought to develop in bones that form through the process of enchondral ossification. In particularly, osteochondromas in the foot mostly occur in metatarsal bones and phalanges. It is seldom found in talus. It is usually confused with osteophyte or enthesis. We report an osteochondroma case confirmed by roentgenographical and pathological investigation, after removing the masses form bilateral tali of a 19-year-old male patient presented with bilateral ankle joint pain for three years.