Reconstructive microsurgery has revolutionized the field of hand surgery by incorporating innovative procedures, such as replantation, free composite tissue transfer and peripheral nerve surgery, in the last few decades, known as the performance decades. The last few years have been a period of maturation.
　To proceed forward, strict analysis based on EBM is imperative to improve the technical and functional outcomes of reconstructive microsurgery, referred to as the science decades. Performance still surpasses science in the field of reconstructive microsurgery.
　The indications of finger-tip replantation, evaluation of motor function by MRC, substitution action following nerve transfer, and reliability of DASH questionnaire were examined, and the significance of quantitative assessment of strength and accurate statistical analysis following microsurgical procedure was emphasized.
　There are many tricks used to obtain good functional outcomes in reconstructive microsurgery, which are based on meticulous microsurgical techniques and in-depth analysis of each case. The limitations of current microsurgical techniques, such as in the double free muscle procedure, are discussed, and I recommend that young microsurgeons integrate microsurgery with technological innovations like stem cells and the bionic hand.

　Pure-skin-perforator (PSP) and super-thin (ST) flaps are useful for thin soft tissue reconstruction, but they require meticulous proximal-to-distal perforator dissection for primary thinning using the conventional elevation method. To address this challenge, the subdermal dissection technique has been developed in which a PSP/ST flap is directly elevated via distal-to-proximal dissection without primary thinning. Precise localization of PSPs is key to successful PSP/ST flap elevation and can be conducted using a portable ultrasound device with a 15-18-MHz probe. Using the subdermal dissection technique and preoperative PSP localization, a PSP/ST flap can be elevated within 30 minutes on average. As the device is widely used by internists and general surgeons, the procedures can be applied in any general hospital without buying an expensive ultra-high-frequency ultrasound device.

　We examined cases of severe lower limb open fracture in which soft tissue was reconstructed by free or pedicled flaps at Nagasaki University Hospital Trauma Center. The cases were divided into two groups: a group in which soft tissue reconstruction was performed within 72 hours (early group) and the other in which it was performed after 72 hours (late group) . There were 8 cases in Early group and 23 in the late group. There was no significant difference in partial flap necrosis, total flap necrosis, postoperative infection, postoperative pneumonia, nonunion or inpatient days. However, deep vein thrombosis was slightly more frequent in the early group. Blood coagulation may have been accelerated by the surgical intervention shortly after severe trauma. A future challenge at our center is to accurately determine whether the limb salvage procedure should be performed for severe lower limb fractures in cases of polytrauma at an early stage of injury.

　When a free flap is applied around the knee, which recipient vessel should be selected has not been established.
　We retrospectively investigated 15 cases of free flap around the knee at our department to examine selection of a recipient vessel related to the reconstruction area. Regarding the reconstruction area, the anterior surface of the knee was divided into 5 areas from A to E, and the popliteal fossa was defined as F.
　The most important factor related to the reconstruction area and selection of a recipient vessel was their anatomical position. For reconstruction of the superior, medial and patellar area of the knee, the descending genicular artery was selected. On the other hand, it was considered difficult to apply the descending genicular artery to the inferior lateral area of the knee and the popliteal fossa. The tibialis anterior artery and lateral superior knee artery are options for the inferior lateral area of the knee. The popliteal artery or its branches are useful for reconstruction of the popliteal fossa.

　As the dorsal skin of the interphalangeal joint is thin, interphalangeal joint infection after minimal injury is common. Debridement is required to treat the infection, but it may cause deformity and loss of strength. Thumb complications are frequent; therefore, the function should be preserved as much as possible. In this report, we treated interphalangeal joint infection with osteomyelitis using the Masquelet technique and dorsoulnar flap, and obtained a good result. The patient was a 63-year-old man with diabetes. Pus was observed from the dorsal skin of his left thumb. We performed debridement and inserted a spacer. After two months, we confirmed control of the infection and performed bone grafting. At the time, there was loss of the dorsal skin of the interphalangeal joint, which was covered by a dorsoulnar flap. The flap was not congested and bone union in the thumb was acquired after 6 months. The DASH score was 0 points and the Hand20 score was 2.5 points. Treatment of interphalangeal joint infection with osteomyelitis using the Masquelet technique and dorsoulnar flap was effective.

　During the 47th annual meeting of the Japanese Society for Reconstructive Microsurgery held at the Kitakyushu International Conference Center from November 20th to the 21st, 2020, the Supermicrosurgery Vessel Anastomosis Contest was carried out as a special event. This was the first attempt by the Japanese Society for Reconstructive Microsurgery, but this contest was received favorably by many members and was a meaningful project. The 2nd contest will be held at the 48th annual meeting of the Japanese Society for Reconstructive Microsurgery in December 2021. In this paper, we reviewed the preparations and management methods for the first contest, and identified points for improvement and issues for the second contest.

　It is currently a global society. All data from foreign countries are readily available on the Internet. Young doctors may wonder if they have to go abroad to have new experiences that cannot be gained locally in Japan. Studying abroad does not improve one’s career. The benefits of studying abroad include 1) gaining new values, 2) improving one’s adaptability, 3) obtaining wide interpersonal relationships, and 4) improving communication skills. In order for the Japanese medical level to become equal to that worldwide, we should take all of these points into consideration. I hope this article will provide answers to the young microsurgeon who is aiming to study abroad in the future.

　I studied the methodology of clinical research under Professor Kevin C. Chung at the University of Michigan in the United States for a year and 9 months from September 2015 to May 2017. In general, the purpose of studying abroad without a medical license in the U.S. is to conduct basic research as a research fellow, and I had no idea what kind of life I would lead across the ocean as a person with little knowledge of basic research. In this article, I introduce the selection of my study abroad destination, the preparations before my trip, my life at my study abroad destination, and the impact of this experience on my subsequent life as a microsurgeon.