Masao Kurokawa

Characteristics of donor and host cells in the early remodeling process after transplant of Achilles tendon with and without live cells for the treatment of rotator cuff defect -what is the ideal graft for the treatment of massive rotator cuff defects?

PURPOSE We examined the characteristics of donor and host cells in the early remodeling process after transplant of Achilles tendon with and without live cells to repair rotator cuff defects. We also clarified which graft with or without live cells was superior in the early remodeling process. MATERIALS AND METHODS Sprague-Dawley (SD) rats and green fluorescent protein (GFP) rats were used; they were divided into 3 groups: in group SD, the Achilles tendons of GFP rats were transplanted into the defects of SD rats; in group GFP, the Achilles tendons of SD rats were transplanted into GFP rats; in group GFP-Fr, frozen Achilles tendons of SD rats were transplanted into GFP rats. At 3 and 7 days after surgery, these sections were examined histologically and immunohistochemically with anti-heat shock protein (HSP) 47 and anti-macrophage antibodies. RESULTS Donor cells gradually decreased, but HSP47-positive donor cells were detected at 3 days in group SD. Host cells infiltrated into the graft from the surrounding tissue, and their numbers in groups SD and GFP gradually increased more significantly than in group GFP-Fr. Macrophages derived from the donor tissue were absent in all groups. The remodeling process of the frozen graft was slower than that in the case of the graft that was not frozen. CONCLUSION These results demonstrate that live donor cells have a positive effect on the remodeling process. Therefore, autografts with live cells considered to be preferred to frozen allografts or synthetic materials without live cells for transplant for rotator cuff defects.

MRI evaluation of the inferior glenohumeral ligament: Comparison with arthroscopic findings in 81 shoulders

Arthroscopic Bankart repair, using staples, requires a thick and wide anterior band of the inferior glenohumeral ligament. We compared MRI and arthroscopic findings of the ligament in 81 shoulders with traumatic anterior glenohumeral instability. When fluid was present in the shoulder, sensitivity and specificity of the MRI evaluation for the presence of a thick and wide ligament were 82% and 100%, respectively. In shoulders without joint fluid, the condition of the ligament was evaluated according to the presence of a low- or moderate-signal triangle structure on the anterior margin of the glenoid cavity in the 3 MR images obtained from the inferior 2 cm of the glenoid. Sensitivity and specificity of the MRI evaluation in cases without fluid were 84% and 93%, respectively. The MR technique needs to be further improved to achieve better sensitivity for preoperative selection of shoulders suitable for Bankart repair with staples.

Association between loss of bone mass due to short sleep and leptin-sympathetic nervous system activity

BACKGROUND Sleep has been reported to be an important factor in bone metabolism, and sympathetic nervous system activity has been reported to regulate bone metabolism. In this study, we evaluated the association between sleep, sympathetic nervous system activity, and bone mass. METHODS The study subjects were 221 individuals (108 males; 113 females; mean age: 55.1±7.0years) divided into two groups: those who slept for less than 6h a day (short sleep [SS] group), and those who slept 6h or longer (normal sleep [NS] group). The groups were compared with regard to lifestyle, cortical bone thickness, cancellous bone density, bone metabolism markers, blood leptin levels, and sympathetic nervous system activity as evaluated by heart rate variability analysis. RESULTS Significant differences were observed between the two groups in cortical bone thickness, blood TRACP-5b, and leptin levels. The L/H ratio (an index of sympathetic nervous system activity) was higher in the SS group than in the NS group. Significant negative correlations were observed between cortical bone thickness and both the L/H ratio and leptin levels, and a significant positive correlation was observed between the L/H ratio and leptin levels. CONCLUSIONS Short sleep was associated with a decline in cortical bone thickness due to the promotion of bone resorption and sympathetic nervous system hyperactivity in the middle-aged group. Leptin levels and cortical bone thickness were found to be closely related, suggesting that cortical bone mass may be regulated via interaction with the leptin-sympathetic nervous system.

Celebrating the 40th anniversary of the Japan Shoulder Society

Established in 1974, the Japan Shoulder Society is the oldest shoulder society in the world. Shoulder societies on other continents were formed much later: North America in 1982, Europe in 1987, South Africa in 1990, and South America in 1994. The original founding members of our society were Dr. Hisao Endo, Dr. Katsuya Nobuhara, and Dr. Nagao Adachi, and a year later, the following four members joined this team: Dr. Ryuji Yamamoto, Dr. Hiroaki Fukuda, Dr. Motohiko Mikasa, and Dr. Kiyohisa Ogawa. The first Society Congress was held on October 18, 1974, in Tokushima City with Dr. Hisao Endo as the first Congress President. He is well known for his sophisticated clinical work on ‘‘loose shoulder’’ or so-called multidirectional instability. His first report of multidirectional instability and the effectiveness of pectoralis major transfer was published in Japanese in 1971 and recently published in English as a Classic Article in the Journal of Shoulder and Elbow Surgery in 2012. In 2013, we had the 40th Annual Meeting of the Japan Shoulder Society in Kyoto with Dr. Masao Kurokawa as the Congress President, and this year, 2014, we are celebrating the Society’s 40th anniversary. We would like to convey our sincere appreciation to all the shoulder and elbow societies in the world and their members for their continuous support. We would also like to thank all the founding members for starting our society and the currentmembers forbuildingupour society. The uniqueness of the Japan Shoulder Society is that it is probably the only society focusing on the shoulder alone, not on the elbow. We also have the Japan Elbow Society, which is an independent society from us, but the majority of the members of the Japan ElbowSociety are hand surgeons. In addition, most patients have isolated problems of the shoulder or the elbow, except throwing athletes, who might have both problems. Because of these reasons, we have not found an urgent need to combine the two societies despite the world trend. We are independent but cooperative at the same time. For example, both societies hosted the 12th International Congress on Shoulder and Elbow Surgery in Nagoya in April 2013, which had 1,150 attendees from 48 countries who actively participated. The meeting was a great success both academically and socially because of the collaboration of the two groups.

Two cases report of recurrent anterior dislocation of the shoulder in aged patients

In aged patients an initial anterior dislocation of the shoulder produces a rotator cuff tear and sporadically advances to a recurrent anterior dislocation(RAD). Two cases of aged RAD with rotator cuff tears(case 1; a 70-year-female case 2; an 80-year-female) were reported in this paper. These cases were treated surgically. The operative findings were large Hill-Sachs lesions and rotator cuff tears without a Bankart lesion. The middle and inferior glenohumeral ligaments were torn at the attachment of the humeral head in case 1 and the mid substance in case 2. The middle and inferior glenohumeral ligaments-labral complex were intact in each case. In case 2, the subscapularis tendon was ruptured and the long head of the biceps tendon was dislocated. The operative findings mentioned above were not found in young patients with an RAD. The substance tear of capsular ligaments is a cause of recurrence and an important factor in aged RAD with a rotator cuff tear.