Objective To explore clinical application of the island flap pedicled of the descending branch of perforating branch from lateral anterior malleolus of peroneal artery in repairing the soft tissue defects in midfoot and forefoot. Methods From January, 2010 to December, 2016, based on the anastomosis between the descending branch from a terminal branch of peroneal artery on the anterior aspect of the lateral malleolus and other branches located around the ankle joint and sinus tarsi, island flap with a pedicle could be harvested more distally and to be used in covering the soft tissue defects in midfoot and forefoot of 5 patients. Sizes of the flap were from 15 cm×12 cm to 8 cm×6 cm. All patients were followed-up in outpatient clinic or through WeChat. The appearance of the flaps and ankle function were recorded simultaneously. Results All flaps were survived without any secondary surgeries. During the follow-up of 6-15 months, the texture of flaps was good with satisfactory estheticity. Range of motion at the injured ankle was 15° in dorsi flexion and 25° in plantar flexion. Conclusion The flap with a pedicle of the descending branch of perforating branch from lateral anterior malleolus of peroneal artery is good enough to be used in the reconstruction of soft tissue defects in midfoot and forefoot. Key words: Peroneal artery; Terminal perforating branch; Island flap; Microsurgical technique

Objective To observe the location and the distribution of distal 1/3 segment of the second dorsal metacarpal artery, the finger web artery and the dorsal digital artery, and to provide anatomical data for repairing the soft tissue defect on the hand with bilobed or multi-lobed micro-flap with second metacarpal dorsal artery-dorsal digital artery. Methods From June, 2018 to March, 2019, 34 fresh adult upper limb specimens were selected. The radial and ulnar arteries were perfused with red latex in 24 specimens. The radial and ulnar arteries were infused with cast materials to make cast specimens in 10 specimens. The location and distribution of the distal 1/3 segment of the second dorsal metacarpal artery, the finger web and the dorsal digital artery were observed. Results The distal 1/3 segment of second dorsal metacarpal artery extended (4±1) cutaneous branches, and continued to become the finger web artery at the plane of the articular surface. The length of the finger web artery was (2.5±0.6) cm, and there were 4 types anastomic methods of communication with arteries. The second dorsal metacarpal artery extended 2 finger dorsal artery to the proximal dorsal skin of the middle finger and index finger. The length of dorsal digital artery was 2.6±0.4 cm and the diameter was 0.2±0.1 mm. Four to 6 micro-cutaneous branches were extended and consistent with the nearby skin cutaneous branches. Conclusion The distal segment of the second dorsal metacarpal artery and the dorsal digital artery is anatomically constant. The distal segment of the second dorsal metacarpal artery and dorsal digital artery are the pedicle for the design of the bilobed flap of middle finger and index finger to repair small soft tissue defect on the thumb and purlicue. Key words: Second dorsal metacarpal artery; Finger web artery; Dorsal digital artery; Bilobed flap; Applied anatomy

Objective To investigate the role of the bionic multi-channel nerve conduit by reducing mismatch of regenerated nerve fibers in the rabbit sciatic nerve defect. Methods The experiment was conducted from July, 2017 to February, 2019. A total of 55 New Zealand white rabbits were randomly divided into two groups (First group, n=30 and Second group, n=25). There were 5 subgroups (n=6) in the first group, which were autograft and custom-anatomic nerve conduits (CANC) with different channel (1-CANC, 2-CANC, 3-CANC, 4-CANC) that implanted to repair the rabbit sciatic nerve defect (10 mm). The electrophysiological, triceps muscle wet weight recovery rate, histological study and ankle index analysis were used to evaluate the treatment of each group at 12 and 24 weeks postoperatively. There were 5 subgroups (n=5) in the second group. The simultaneous retrograde tracing method was applied to compare with the number of mismatched nerve fibers at 24 weeks postoperatively. All data were recorded and analyzed by One-way ANOVA method, the Turkey’s method was used to compare the differences between each subgroup. The difference was considered to be statistically significant if P<0.05. Results The autograft group showed the best recovery in the electrophysiology, histology study and ankle index at 12 and 24 weeks postoperatively (P 0.05), but diameters of nerve fiber and myelin thickness were higher in 2-CANC and 3-CANC [(10.67±0.56) μm,(10.65±0.53) μm, respectively] compared with 1-CANC and 4-CANC groups [(8.43±0.63) μm, (9.03±0.55) μm, respectively]. The differences were similar in electrophysiological, wet weight recovery rate of triceps muscle, histological study and ankle index analysis. Simultaneous retrograde tracing showed that the autograft group had highest total number of labeled profiles, but no significant difference of the total number of labeled profile was showed among the CANC groups. However, the 1-CANC group[(7.1±2.4)%] showed highest percentage of the FB-NY-neurons than other CANC groups[(2.7±1.9)% in 2-CANC, (2.5±2.3)% in 3-CANC, and(2.2±1.2)% in 4-CANC](P<0.05). Conclusion The autograft group showed the best results among all groups. Compared with the 1-CANC group, the 2-CANC and 3-CANC group obtained more mature regenerated nerve fibers and with a fewer mismatch rate. Moreover, that did not affect the number of regenerated fibers. Key words: Rabbit; Sciatic nerve defect; Nerve conduit; Bionic; Multi-channel; Regenerative nerve fiber mismatch

Objective To introduce the repairation procedure of composite distal soft tissue defect of thumb and finger with mini toenail flap. Methods From June, 2015 to June, 2018, 7 cases with composite tissue defect at 7 distal fingers, including 5 thumbs, 1 index finger and 1 middle finger, were reconstructed with mini toenail flap transfer. The flap sizes which were raised during the operation ranged from 4.5 cm×3.0 cm-3.0 cm×1.5 cm. The donor sites were covered by toe phalanx shortening, V-Y advancement flap and local pedicle flap. Microsurgical routine treatment was made after the operation, and followed-up regularly. Results Seven flaps of 7 cases completely survived without any necrosis. All the wounds at the donor sites healed well. All patients were followed-up for 6-36 months. The motive, sensor and cosmetic result were satisfied. In sensory function, the two-point discrimination distance could restore to be 4-6 mm. Conclusion The mini toenail flap transfer is a reliable and suggested method. It can anatomically restored the distal digit sensor function with cosmetic contour, and regain the motive, sensory function and satisfied cosmetic appearance. Key words: Toenail flap; Toe transplantation; Finger; Repairation; Distal finger defect

Objective To investigate the effectiveness of the digital technology in repairing hand soft tissue defect with the lateral arm perforator flap. Methods From January, 2015 to February, 2018, 15 cases of hand soft tissue defect were treated with free lateral arm perforator flaps transferring. Injury site: 7 cases on the back of the hand, 4 cases on the palm, and 4 cases on the mouth of the tiger. All of them had tendon exposure. The size of defect was 2.0 cm×1.5 cm to 14.0 cm×5.0 cm. CT angiography was conducted and analyzed before operation, and the donor sites and preferred perforators were selected. Then the CTA data was imported into the Mimics 17.0 software to reconstruct the three dimensional structure of the perforators, bone, and skin. The flap was obtained on the basis of preoperative design during operation. The size of flaps varied from 3.0 cm×2.0 cm to 15.0 cm×6.0 cm. The survival status of the flap, the appearance and function of the hand were followed-up and analyzed after operation. Results All the flaps survived. The wounds and incisions at donor sites healed primarily. The patients were followed-up for 6-12 (mean, 8) months. The hand function recovered satisfactorily, and the sensation was S2-S3 at 6 months after operation. According to the functional assessment criteria of upper limb formulated by the Hand Surgery Branch of Chinese Medical Association, the results were excellent in 4 cases, good in 9 cases, and fair in 2 cases. The linear scars were observed at the donor sites. Conclusion The lateral arm perforator flap has a stable vessel pedicle, good texture and sensation. So it is a good method to repair soft tissue defects of hand. The preoperative individualized design of the lateral arm perforator flap can realize through CTA digital technology and Mimics 17.0 software. It can reduce the operation risk. Key words: Lateral arm perforator flap; CT angiography; Hand; Repair

Objective To localise and evaluate the precise position of the shank perforators preoperatively with the CTA and hand-held color Doppler (HHD) , then evaluate the clinical efficacy of the method. Methods From April, 2013 to June, 2017, designed 36 propeller perforator flaps in 36 patients by following methods. Firstly, the CTA test was performed to calculate the parameters of perforator vessel positioning. Secondly, a HHD was typically used to verify the location of perforators found on preoperative CTA. At last, according to the with like principle, the propeller perforator flaps were accurately designed. The regular followed-up was performed. Results All patients were followed-up for 3-24 months after operation. Thirty-six propeller perforator flaps survived, and 3 cases among them showed partial epidermal necrosis and healed after skin grafting. Donor sites were closed primarily in 24 cases, and skin grafting were performed in 12 cases. The skin graft sites survived without necrosis, and the average time of cutting flaps was 45 min. Conclusion By the methods of mapping the perforator propeller flaps with CTA and HHD, the perforator vessel can be positioned more accurately and quickly. The operation time was shortened, and the clinical efficiency can be achieved with the good clinical application values. Key words: Propeller flap, perforator flap; CT angiography; Hand-held Doppler ultrasound; Shank

Objective To investigate the clinical effect of infective foot ulcer and soft tissue defects of small area with free peroneal artery perforator flap. Methods From February, 2016 to Apirl, 2017, 9 cases of infective foot ulcer and soft tissue defect of small area were repaired with peroneal artery perforator flap. Cause of infection: injury in 6 cases, diabetes in 2 cases, spinal cord injury subsequent pressure sore in 1 case. Infective ulcer part: 4 cases on plantar metatarsophalangeal joint, 2 cases on dorsal metatarsophalangeal joint, 2 cases on interior of the first metatarsophalangeal joint and 1 case on the heel. Defect area: 3.0 cm×2.0 cm-5.0 cm×3.0 cm; flap area: 4.0 cm×3.5 cm-7.0 cm×4.5 cm. The donor sites were sutured directly. All the flaps contained lateral sural cutaneous nerve. In order to rebuild the sensation of flaps, nerves between surgical area and receiving area were received end-to-side anastomosis. Outpatient follow-up was used in all patients. Results All the flaps survived, and all the wounds were primary healed, without recurrence of infection. All patients were followed-up from 6 to 24 months with an average of 16 months. The appearance of flaps was good with slight bloated. The texture and color of the flaps were close to the recipient site. Flap feel was good except the cases of diabetes and spinal cord injury pressure sore. The AOFAS score at last follow-up time was 80.05±7.80, which was excellent in 5 cases, good in 2 cases, and fair in 2 cases. Conclusion The free peronerl artery perforator flap has many advantages, such as vascular anatomy constant, blood supply is reliable, thickness moderate, easy to get, strong resistance to infection, small district damage, etc. It is a useful clinical method to repair foot infection ulcer and soft issue defects of small area. Key words: Peroneal atery perforator flap; Foot; Infective ulcer; Repair

Objective To explore the operative technique and clinical results of posterior tibial artery perforator flap within saphenous nerve branch for sensory reconstruction. Methods From January, 2016 to June, 2018, 9 patients suffered from soft tissue defect were treated by the posterior tibial artery perforator flap containing saphenous nerve branch. Seven patients were males and 2 were females, with age ranged from 31 to 62 years. Soft tissue defects located in hands in 5 patients, plantar in 2 patients, ankle in 1 patient and dorsal foot in 1 patient. The size of soft tissue defects ranged from 8.0 cm×2.5 cm to 21.0 cm×4.0 cm. The regular post-operative followed-up was performed. Results All flaps survived without complications. The size of flap ranged from 10.0 cm×3.5 cm-23.0 cm×5.0 cm. Donor sites were primarily closed in 5 patients and secondary closed in 4 patients. Followed-up ranged from 6 to 15 months with 10 months in average. The contour of flaps were satisfied and the sensory function of the donor sites were normal. At 6 months followed-up, SW test reached 5.07 in all flaps, and 2PD ranged from 14 to 35 mm. Conclusion The novel sensory flap can provide satisfied sensory outcome without sacrificing main artery and saphenous nerve, and is a good candidate for sensory reconstruction of soft tissue defects. Key words: Posterior tibial artery; Perforator flap; Saphenous nerve; Sensory reconstruction; Soft tissue defect

Objective To evaluate the clinical safety of the collagen nerve scaffold with longitudinally oriented microchannels in bridging peripheral nerve defect. Methods Five patients with 8 peripheral nerve defects of 18 to 30 (mean, 23.8) mm in length were involved in the pilot study and treated from July, 2017 to March, 2018, including 6 digital nerves and 2 medial antebrachial cutaneous nerves. The defects were repaired with the collagen nerve scaffold with longitudinally oriented microchannels independently developed. Routine therapy of prophylactic systemic antibiotics but no immunosuppressive drugs was given to all patients post-operatively. All patients were followed-up by regular review in the outpatient department combined with WeChat and telephone. The clinical safety of the nerve scaffold was preliminarily evaluated through observing the condition of the healing of the local wound and the whole body. The blood routine examineation and biochemical test were detected. The statistical analysis of the measurement data was performed by the analysis of variance of repeated measurement data, and the difference was statistically significant when P<0.05. Results All patients were followed-up for 7 to 15 months (average, 10 months). No adverse events such as infection, allergy, damage of liver and kidney function occurred. The operative incisions healed primarily, with no redness, exudation and rupture in the local area. There was no systemic symptoms such as fever, nausea, vomiting, skin itching, etc. The results of blood routine tests and biochemical tests were normal. The data of tests was compared, and the difference was not statistically significant (P>0.05). Conclusion The preliminary study shows that it is clinically safe to bridge peripheral nerve defects with the collagen nerve scaffold with longitudinally oriented microchannels. Key words: Collagen nerve scaffold with longitudinally oriented microchannels; Peripheral nerve; Nerve defect; Safety