The present article describes the treatment of femoral segmental bone defects at the Hand and Trauma Reconstruction Center (Juntendo University Urayasu Hospital) . A retrospective study was conducted on 8 cases of femoral segmental bone defects of over 6 cm. Six cases were less than 10 cm and reconstructed by bone grafting using the Masquelet technique. Two cases were over 10 cm and treated by bone grafting using the Masquelet technique and vascularized bone graft (VBG) method. Bone union was achieved in all cases and no complications were observed. In order to minimize the graft, it is highly recommended that bones be reconstructed through intramedullary nailing wherever possible, and for defects larger than 10 cm, hybrid treatment using the Masquelet technique and VBG is recommended.

　The indications for mandibular reconstruction using a mandibular reconstruction plate (MRP) and free flap, and the complication-reducing technique remain controversial.
　In 2014, one investigator reported on the “no touch technique,” which protected the MRP from oral saliva exposure to prevent postoperative MRP infection. We developed an easier method that was comparable with this technique. We report this new procedure and the complications that developed in an additional 30 cases of mandibular reconstruction.　
　Between 2016 and 2019, 29 patients (22 men, 7 women; mean age, 70.0 years) underwent 30 mandibular reconstructions using the MRP and free flap. In 15 cases during reconstruction, the MRP and screws were removed from the mandible and soaked in a povidone-iodine solution during microvascular anastomosis. Before this maneuver, the MRP and screws were exposed temporarily to oral mucosa and saliva, which meant that the “no-touch” technique was no longer maintained.　
　A rectus abdominis musculocutaneous flap was used in 25 cases (83.3%) and an anterolateral thigh flap (ALT) was used in 5 (16.7%) . All free flaps survived except for two ALTs that had partial flap necrosis. MRP exposure was noted in 3 cases (10.0%) , but it was not related to MRP infection.
　This procedure may be sufficient to prevent local infection of the MRP.

　Although the success rate of free tissue transfer was recently reported to exceed 95%, this value includes 5 to 25% of cases that required salvage surgery due to postoperative vascular compromise. If the risk factors for vascular compromise after free tissue transfer can be identified, the frequency of salvage surgeries may be reduced. In this study, we investigated the associated risk factors for vascular compromise after free tissue transfer using multivariate analysis focusing on factors deemed as intervenable. A retrospective review was conducted on 115 patients who underwent a total of 123 free tissue transfers for both the upper and lower extremities. We identified 11 (8.9%) cases of vascular compromise, 9 of which were salvaged, equating to an overall success rate of 98.4%. Multivariate analysis revealed the following significant risk factors leading to vascular compromise: female sex［odds ratio=14.5 (95% confidence interval［CI］2.11-91.08, p=0.005) ］, lower extremity cases［odds ratio=8.3 (95% CI 1.45-44.34, p=0.015) ］, and the use of the superficial venous system as a recipient vein［odds ratio=41.9 (95% CI 3.25-487.21, p=0.004) ］. Our study demonstrated that selection of the recipient vein is an important factor when aiming to prevent vascular compromise during surgery.

　Selecting an appropriate recipient vessel is the most important factor for successful free flap transfer in the reconstruction of severe lower extremity trauma. In this study, the relationship between the choice or status of the recipient vessel and the incidence of complications, such as flap failure, intraoperative vasospasm due to post-traumatic vessel disease (PTVD) , and early revision surgery, was investigated for 34 flaps in 32 patients who underwent microsurgical soft tissue reconstruction.
　The choice of recipient vessel (posterior tibial artery［PTA］vs anterior tibial artery［ATA］) and whether an injured vessel was used as a recipient vessel did not significantly affect the complication rate if the vessel was used within a few days from the day of injury.
　Therefore, the PTA or the ATA can be used as a recipient vessel depending on the technical convenience of the surgery, and avoiding injured vessels is not necessary if the operation is performed within a few days after injury. To prevent vasospasm due to PTVD, the recipient vessel must be anastomosed as far as possible from the zone of injury and the surgery must be performed as early as possible after the day of injury.

　We surveyed the details of salvage surgery to examine the causes of circulatory problems following free flap reconstruction for severe trauma in 63 limbs and identified measures to solve such problems. We assessed five patients (four men and one woman) who underwent salvage surgery for circulatory problems. The upper limbs were affected in two patients and lower limbs in three patients. Their mean age was 51.2 years (26?80 years) . The mean time from completion of surgery to entering the operating room to undergo salvage surgery was 19.6 h (6?36 h) . The vascular findings at the time of salvage surgery included arterial inflow failure (1 patient) , arterial thrombus (1 patient) , venous thrombosis (1 patient) , and venous compression on the flap side of the anastomosis (2 patients) , for which relevant treatment was administered. All flaps survived. When vascular problems are detected after free flap reconstruction for trauma of the limbs and managed early, the cause of the problems is identified and the success rate of salvage surgery is high.

　Extension contracture due to extensor tendon adhesions after trauma is difficult to improve because re-adhesion and loosening of the extensor tendon can be difficult to treat even after extensor tenolysis.
　In this study, we used a perforator adipofascial flap (PAFF) as a gliding bed during extensor tenolysis to prevent tendon re-adhesions, in addition to joint mobilization.
　This technique was performed on four fingers in four cases of post-traumatic extension contracture: two in the middle finger proximal interphalangeal (PIP) joint, one in the little finger metacarpophalangeal (MP) joint, and one in the thumb MP joint.
　In one case of primary tenolysis, good improvement in the range of motion was observed. The other three patients underwent multiple surgeries; improvement in the range of motion was slightly lower, but re-adhesion was prevented, and extension range of motion was maintained and improved.
　PAFFs were considered useful not only in preventing re-adhesion of the extensor tendon, but also in reducing extensor tendon loosening because a sufficient amount of the PAFF was able to be inserted under the extensor tendon.

　We report the selection of the anastomotic artery in 21 cases of thumb replantation. The patients were 20 males and 1 female, and the average age was 46 years. Twenty thumbs (95%) survived.
　In Zone I・II, the radial digital artery was used in all cases as a proximal artery except in one case in which the central artery was anastomosed together. In Zone I・II, the radial digital artery was the first choice in reconstructive artery.
　Among cases where only the radial or ulnar digital artery was able to be reconstructed in Zone III, the ulnar digital artery was used as a proximal artery in 80%.
　Among cases where both the radial and ulnar digital arteries were able to be reconstructed in Zone III, the ulnar digital artery was able to be used as a proximal artery in 89%. In Zone III, the ulnar digital artery was the first choice for an anastomotic artery. In Zone V, the branch of the palmer arch or the dorsal branch of the radial artery was necessary as a reconstructive artery.

　We evaluated the clinical outcomes and treatment course in 8 patients with crush wounds in the dorsal hand that required soft tissue reconstruction. The mechanism of injury was crush injury in 7 cases and degloving injury in 1 case. The average time from injury to soft tissue reconstruction was 9 days (7?12 days) , except in 1 case in which a free anterolateral thigh (ALT) flap was performed 101 days after the initial injury. Free ALT flaps were applied in 7 cases and a reverse posterior interosseous artery flap was applied in 1 case. Four cases (11 affected digits) had complex injuries, including bone and/or tendon injury. In 3 of the 4 cases with complex injuries, 9 digits had severe contracture of the metacarpophalangeal joint with an arc <30 degrees. Complete rehabilitation was not achieved in these 3 cases due to inadequate bone fixation, insufficient debridement leading to infection, and inadequate soft tissue reconstruction. The clinical results of cases without bone/tendon injury were satisfactory when the appropriate soft tissue reconstruction was performed. Severe crush injuries of the bone/tendon often result in severe adhesion and contracture, and early rehabilitation, including adequate bone/tendon reconstruction and soft tissue reconstruction in the metacarpophalangeal joint-flexed position, is essential in such cases.

　Twenty proper digital nerves of 20 patients were repaired using the all collagen-made nerve conduit “RENERVE^®” between April 2018 and April 2020, and retrospectively investigated. Eleven males and 9 females with a mean age of 42 years old (range 19-75 years) were included. The affected digits included 5 thumbs, and 8 index, 4 middle, 1 ring and 2 little fingers. The mean number of days until surgery (from the day of injury to surgery) was 27.9 (range 0-186) and the average nerve gap was 9.8 mm (range 5-20) . After a mean follow-up of 13 months, the mean static and moving two-point discriminations were 9.0 mm and 6.4 mm, respectively. On the Semmes-Weinstein test for the repaired digits, 12 digits were blue, 7 were purple and 1 was red. The pain score during the final follow-up was 10.4/100. Regarding factors related to sensory recovery after nerve repair, nerve defect length was strongly correlated with both two-point discriminations (p<0.01) . The collagen conduit was considered to be an effective option that offered acceptable sensation and nerve function for the short gap of the proper digital nerve.

　Good clinical results have been reported after the use of vascularized bone grafts, the Masquelet technique (induced membrane technique), the bone transport technique with external fixation, and other methods in reconstructive surgery for bone defects caused by major trauma. In this paper, we report a case of reconstructive surgery using a free vascularized fibular bone graft for infected pseudarthrosis after reconstruction of an open fracture of the distal femur using the Masquelet technique as primary treatment. Based on our case, the Masquelet technique using autologous bone may increase the difficulty of long bone defect reconstruction because the limited amount of autologous bone that can be extracted prevents the tight filling of major bone defects. In the treatment of severe open fractures, it is important to make a detailed reconstructive plan for bone and soft tissue in advance, and to consider whether it can be accomplished. Referrals to major trauma centers should be considered if the plan may not be feasible.

　In this report, the results of applications of thin corticoperiosteal grafts harvested from the supracondylar region of the femur for post-traumatic non-union or avascular necrosis of the tarsal bone are presented. Post-traumatic morphological changes of the tarsal bone due to non-union and/or avascular necrosis are difficult therapeutic challenges. After the development of osteoarthrosis and advancement of destruction of the anatomical alignment of the foot, arthrodesis is indicated. To prevent this, it is necessary to achieve bone union and revascularization of necrotic bone. Vascularized bone grafts can preserve the talus when secondary osteoarthrosis has not developed. Therefore, free vascularized thin corticoperiosteal grafts were used to treat patients with non-union of navicular fractures and post-traumatic avascular necrosis of the talus in whom conventional treatment failed. As this graft consists of periosteum with a thin layer of outer cortical bone, it is elastic and readily conforms to the recipient bed configuration. Uneventful bony union was achieved in all patients.

　Anterolateral thigh flaps (ALT flaps) are useful for soft tissue reconstruction in the treatment of severe limb trauma. Many anatomical variations of the vascular pedicle of ALT flaps require skilled flap elevation. Although there have been many reports on anatomical variations of the vascular pedicle of ALT flaps, those on the anatomical anomalies of the venae comitantes of the perforator are limited. We report a case of an ALT flap with an anatomical anomaly of the venae comitantes of the perforator. The ALT flap was performed for a patient with a traumatic soft tissue defect in the lower extremity. Due to anatomical anomaly of the venae comitantes of the perforator, the perforating artery was ligated during flap elevation. The ligated perforator artery was anastomosed microscopically to the distal part of the descending branch of the lateral circumflex femoral artery to secure circulation of the ALT flap. The ALT flap survived without complications and the postoperative course was uneventful.

　We report a case of reconstruction with a free flap for a post deep burn ulcer with an exposed patella. Bone or tendon is located directly below the skin in the lower extremity, especially around the knee, and blood flow around the knee is unstable. Therefore, intractable ulcers are not uncommon. There are many methods for reconstructing defects of the lower extremities such as direct closure, skin grafting, local flaps, and free flaps. When considering free flap transfer for knee defects, recipient vessel selection is the main challenge. We selected the descending genicular artery as the recipient vessel and applied a latissimus dorsi free flap to cover the defect. The flap survived without notable complications. One year after the operation, the patient was able to walk without difficulties in daily life. The descending genicular artery is useful as the recipient vessel in reconstruction with free flaps in patients with lower limb trauma.

　We treated a case of iatrogenic high median nerve injury that occurred during elbow arthroscopy. Arthroscopic debridement and free body resection were performed in a 47-year-old man because of osteoarthritis in the dominant right elbow joint. Postoperatively, he complained of complete median nerve palsy, except in the thenar muscle, and poor function in his hand. We explored the median nerve and confirmed a 7-cm defect at the elbow joint level. We grafted the sural nerve to a nerve branch from the pronator teres and two sural nerve cable grafts to close the median nerve defect. In addition, the branch of the radial nerve to the ECRB was transferred to the AIN to restore thumb and finger flexion. Seventeen months postoperatively, AIN function recovered, and muscle strength increased to MMT 4; the patient was able to fully create the “perfect O” sign. The FCR, FDS, FPL and index finger FDP scores were MMT 4. Sensation recovered to “blue” in the thumb and “purple” in the index finger on the Semmes-Weinstein monofilament test. The APB was spared because of ulnar nerve innervation. Median nerve function recovered well and the patient returned to his previous work (bone setter) .

　The graft on flap method is useful for fresh fingertip amputation. We report a case in which the composite graft method was used after injury and the graft on flap method was used for cutaneous graft necrosis on day 12. A 48-year-old woman sustained complete amputation of her little finger after getting her hand caught in a machine at work. The injury was crush type and the amputation level was subzone II (Ishikawa’s classification) . The osteo-cutaneous composite graft method was applied 2 and a half hours after injury. As cutaneous graft necrosis observed on day 12, the graft on flap method was performed on the same day. The defect lesion was covered with a volar V-Y advanced flap after the distal phalanx fragment was fixed. The flap survived and union of the distal phalanx fracture was achieved 2 months after surgery. The nail grew 3 months after surgery. Seven months after surgery, she had neither numbness nor pain, and had no difficulties. The graft on flap method may be effective in cases where bone and nail bed grafts survive even if the operation is delayed.