Objective:To investigate the techniques of digit-tip replantation with anastomosis of superior digital arch artery in children and to evaluate the clinical effects.Methods:From January 2020 to September 2022, 62 children (62 digits) with completely severed digit-tips were admitted to the Department of Paediatric Orthopaedics, Suzhou Ruihua Orthopaedic Hospital. All the injury planes were distal to the nail root. All arterial dissections were distal to the digital arterial arch with the vessel calibre from 0.15 mm to 0.35 mm. The superior arch arteries of the digital arterial arch were successfully anastomosed. After surgery, a significant blood flux to the replanted digit body were observed. Postoperative necroses or failures were analysed for the causes. All children with survived digit-tips were entered into scheduled follow-ups through a combination of visit of outpatient clinics or via WeChat and telephone reviews. Postoperative follow-up included digit body fullness, motion of distal interphalangeal joint, nail growth, scarring, and response of the replanted digit-tips to needling. Clinical outcomes were evaluated according to the evaluation criteria for finger replantation function.Results:Of the 62 replanted digit-tips, 56 survived after replantation. Two digits had wound infection after surgery, and survived by dressing change and applying sensitive antibiotics. Necrosis occurred in 6 replanted digit-tips, of which 2 necrotic digit bodies were amputated, and the stumps at the distal interphalangeal joint were repaired. The other 4 necrotic digits were healed after dressing change under the scab due to a smaller digit body. A total of 52 children (including 2 survivals from postoperative infection after dressing changes and 4 survivals with healing underneath-eschar after necrosis) and with 10 lost during follow-up (including 2 with stump repairs after necrosis). The follow-up period ranged from 2 to 30 months, with an average of 6 months. The shape and function of replanted digit-tips recovered well. According to the evaluation criteria for finger replantation function, 44 digits were of excellent, 6 of good, and 2 of fair.Conclusion:In children, the superior arch arteries of digital arterial arches of the digit-tips are small in diameter. However, the vessels in smaller calibres can be anastomosed, should proper surgical techniques are applied. Therefore, due to the satisfactory outcomes, microsurgeons should try the best efforts to replant a digit severed at the plane of digit-tip.

Objective:To explore the effects of the first dorsal metatarsal artery terminal branch flaps in repairing skin and soft tissue defects of fingers.Methods:The study was a retrospective observational study. From October 2021 to December 2022, 44 patients with skin and soft tissue defects in 55 fingers who met the inclusion criteria were admitted to Suzhou Ruihua Orthopedic Hospital. There were 39 males (48 fingers) and 5 females (7 fingers), aged 18 to 54 years. The single wound area after debridement ranged from 1.5 cm×1.0 cm to 3.0 cm×2.0 cm. The color Doppler ultrasonography was performed before operation to locate the first dorsal metatarsal artery and its terminal branches, and a first dorsal metatarsal artery terminal branch flap was designed according to the wound condition, with the area of harvested single flap ranged from 1.7 cm×1.2 cm to 3.2 cm×2.2 cm. The wounds in the flap donor areas were transplanted with full-thickness skin grafts from ipsilateral inner calf. The type of flap was recorded, and the diameter of the terminal branch of the first dorsal metatarsal artery was measured during operation. The survival of the flap was observed one week after operation. The wound healing in the flap donor and recipient areas was observed two weeks after operation. At the last follow-up, the functional recovery of the affected fingers was evaluated by the trial standards for evaluation of partial function of upper extremity by the Hand Surgery Society of Chinese Medical Association, the sensory function of the flap was evaluated using the sensory function evaluation standard of British Medical Research Council, the scar in the donor and recipient areas of the flap was evaluated using the Vancouver scar scale (VSS), and the Allen test was conducted in the toe of flap donor area to evaluate the blood flow.Results:The monoblock type flaps in 31 patients and flow-through type flaps in 2 patients were used to repair wounds in single finger, 2 monoblock type flaps in 8 patients were used to repair wounds in 2 fingers at the same time, and the single-pedicle and two-flap type flaps in 3 patients were used to repair wounds in 2 fingers at the same time. The diameter of the fibular terminal branch of the first dorsal metatarsal artery ranged from 0.40 to 1.10 mm, and the diameter of the tibial terminal branch of the first dorsal metatarsal artery ranged from 0.70 to 0.75 mm. All the flaps survived at one week after operation, and all the wounds demonstrated optimal healing in the flap donor and recipient areas at two weeks after operation. All patients were followed up for 6 to 18 months. At the last follow-up, the functional recovery of 48 fingers was evaluated as excellent, and the functional recovery of 7 fingers was evaluated as good; the sensory function of 8 flaps was rated as S2, and the sensory function of 47 flaps was rated as S3, and the two-point discrimination distance of the flaps was 8-14 mm; the VSS scores in the flap recipient areas ranged from 3 to 6, and the VSS scores in the flap donor areas ranged from 4 to 7; the Allen test result of the toes in the donor areas were all negative with normal blood flow.Conclusions:The first dorsal metatarsal artery terminal branch flaps have several advantages, including relatively hidden donor area, shallow anatomical level, simple intraoperative operation, and flexible flap design. The flap is incised without damaging the main artery of the toe, which can repair skin and soft tissue defects of the fingers and ensure the utmost protection of the toes in donor areas. The fingers exhibit improved appearance, texture, sensation, and function after operation.

Objective:To explore the application value and treatment effects of multiple free anterolateral perforator flaps of calf for reconstruction of multiple digital wounds in single hand.Methods:From August 2020 to March 2022, 12 patients with soft tissue defects in 35 digits were treated in Department of Hand Surgery, Suzhou Ruihua Orthopaedic Hospital. Ten patients were male and 2 were female, aged 25 to 58 years old. Of the patients, 1 had soft tissue defects in 5 digits, 3 in 4 digits, 2 in 3 digits and 6 in 2 digits. The size of defects was from 1.2 cm ×1.2 cm to 7.0 cm×3.5 cm after debridement. The vascular perforators discovered from intraoperative explorations were found originating from the superficial peroneal artery in 24 flaps, from the peroneal artery in 7 flaps and from the anterior tibial artery in 4 flaps. During surgery, the perforator artery and accompanying veins of the flaps were anastomosed with the proper digital artery and palmar or dorsal subcutaneous veins in the recipient site, respectively. The size of the flaps was from 1.5 cm×1.5 cm to 7.5 cm×4.0 cm. No nerve was affected in the surgery. The wound at donor sites in the calf was sutured directly. Regular postoperative follow-ups were conducted at outpatient clinics. The comprehensive evaluation scale of flap was used to assess the conditions of the donor and recipient sites.Results:In this study, all 35 soft tissue defects of digits in 12 patients were reconstructed by the anterolateral perforator flaps of calf. All the 35 flaps survived after surgery, with a 100% of survival rate. The patients were instructed to carry out early functional training after surgery. Follow-up lasted 6 to 24 months, with an average of 11 months. Twenty-five flaps were found in slightly swollen, and further flap thinning surgery were carried out 3 months after the primary surgery, while the rest of the flaps had good appearance and texture. At 6 months after surgery, all flaps recovered a partial deep and shallow sensory and sense of touch. All wound at donor sites in calf had one-stage healing without dysfunction. The comprehensive evaluation scale was excellent in 28 flaps and good in 7 flaps. The excellent and good rate was 100%.Conclusion:It is an effective method to use multiple free anterolateral perforator flaps of calf to reconstruct multiple digit defects in single hand. The flaps can be conveniently harvested and the multiple digital defects in single hand can be reconstructed in primary surgery with small damages to the donor sites and together with satisfactory clinical outcomes.

Objective:To explore the effects of tensile force on vascular lumen formation in three-dimensional printed tissue.Methods:The experimental research method was used. Human umbilical vein endothelial cells (HUVECs) were extracted from discarded umbilical cord tissue of 3 healthy women (aged 22 to 35 years) who gave birth in the Department of Gynaecology and Obstetrics of Suzhou Ruihua Orthopaedic Hospital from September 2020 to May 2021. Human skin fibroblasts (HSFs) were extracted from discarded normal skin tissue of 10 male patients (aged 20 to 45 years) who underwent wound repair in the Department of Hand Surgery of Suzhou Ruihua Orthopaedic Hospital from September 2020 to September 2022. After identification of the two kinds of cells, the 4 th to 6 th passage of cells were taken for the follow-up experiments. HUVECs and HSFs were used as seed cells, and polycaprolactone, gelatin, hyaluronic acid, and fibrin were used as scaffold materials, and the three-dimensional printed vascularized tissue was created by three-dimensional bioprinting technology. The printed tissue with polycaprolactone scaffold of 6 and 10 mm spacing, and without polycaprolactone scaffold were set as 6 mm spacing polycaprolactone group, 10 mm spacing polycaprolactone group, and non-polycaprolactone group, respectively. After 4 days of culture, the printed tissue in 10 mm spacing polycaprolactone group was selected to detect the cell survival by cell viability detection kit, and the cell survival rate was calculated. After 14 days of culture, the printed tissue in three groups were taken, and the shape change of tissue was observed by naked eyes; immunofluorescence staining was performed to observe the arrangement of filamentous actin, and lumen diameter, total length, and number of branches of vessel in the tissue. The tissue with micro-spring structure in the above-mentioned three groups was designed, printed, and cultured for 9 days, and the tensile force applied in the printed tissue was measured according to the force-displacement curve. The number of samples was all 3 in the above experiments. Data were statistically analyzed with one-way analysis of variance and Tukey test. Results:After 4 days of culture, the cell survival rate in printed tissue in 10 mm spacing polycaprolactone group was (91.3±2.2)%. After 14 days of culture, the shape change of printed tissue in non-polycaprolactone group was not obvious, while the shape changes of printed tissue in 6 mm spacing polycaprolactone group and 10 mm spacing polycaprolactone group were obvious. After 14 days of culture, the arrangement of filamentous actin in the printed tissue in non-polycaprolactone group had no specific direction, while the arrangement of filamentous actin in the printed tissue in 6 mm spacing polycaprolactone group and 10 mm spacing polycaprolactone group had a specific direction. After 14 days of culture, The vascular lumen diameters of the printed tissue in 6 mm spacing polycaprolactone group and 10 mm spacing polycaprolactone group were (6.0±1.3) and (10.8±1.3) μm, respectively, which were significantly larger than 0 μm in non-polycaprolactone group ( P<0.05), and the vascular lumen diameter of printed tissue in 10 mm spacing polycaprolactone group was significantly larger than that in 6 mm spacing polycaprolactone group ( P<0.05); the total length and number of branches of blood vessel in the printed tissue in 6 mm spacing polycaprolactone group and 10 mm spacing polycaprolactone group were significantly shorter or less than those in non-polycaprolactone group ( P<0.05), and the total length and number of branches of blood vessel in the printed tissue in 10 mm spacing polycaprolactone group were significantly shorter or less than those in 6 mm spacing polycaprolactone group. After 9 days of culture, the tensile forces applied in the printed tissue in 6 mm spacing polycaprolactone group and 10 mm spacing polycaprolactone group were (2 340±59) and (4 284±538) μN, respectively, which were significantly higher than 0 μN in non-polycaprolactone group ( P<0.05), and the tensile force applied in the printed tissue in 10 mm spacing polycaprolactone group was significantly higher than that in 6 mm spacing polycaprolactone group ( P<0.05). Conclusions:The three-dimensional printed scaffold structure can exert different tensile force in the printed tissue, and the vascular lumen diameter of the printed tissue can be regulated by adjusting the tensile force.

Objective:To investigate the feasibility and clinical efficacy of the bilobed anterolateral femoral perforator flap pidicled with the oblique branch of lateral femoral circumflex artery in repair of the wounds in extremities.Methods:A study was conducted on 36 patients with complex limb wounds from December, 2014 to May, 2020. Thirty patients had single-wound sized from 10.0 cm×10.0 cm to 23.0 cm×17.0 cm, and 6 patients had 2 adjacent and discontinuous wounds sized from 4.0 cm×5.0 cm to 11.0 cm×9.0 cm. A total of 78 perforators were identified in routine preoperative CDU examination, and 67 perforators were confirmed. According to the actual requirement of the perforator confirmed in surgery, 19 flaps were designed with completely split up into bilobed flaps and 17 bilobed fascial flaps were designed with segmented skin and deep fascia. The blood supply of flaps relies on the anastomosis of oblique branch with the recipient vessels, therefore bridged blood Flow-through anastomosis was performed in 8 flaps. All thigh donor sites were sutured directly. Regular follow-up were made after surgery.Results:In this group, 35 cases of bilobed flaps survived successfully. Venous crisis was found in 1 case of flap repairing 2 wounds after the operation and was relieved 7 days later by remove some stitches and bloodletting. The donor sites healed by first intension, and the wound healing time was 11-83 days. All patients were followed-up for 6-39 months. The flaps had good colour and texture with S 2-S 3 sensory. All the donor sites left linear scars except 1 where left with a large scar without contracture and pain. Conclusion:The repair of the wounds in extremities by bilobed anterolateral thigh perforator flaps pedicled with the oblique branch of the lateral femoral circumflex artery could obtain a more concealed donor site. It acts as a beneficial supplement when a bilobed flap cannot be harvested on the descending branch of the lateral femoral circumflex artery.

Degloving injury of distal thumb is common in hand surgery. Generally, the degloving tissue is severely damaged without conditions for replantation. It is often treated by methods of stump revision, local flap coverage, free second toe reconstruction, and so on. It inevitably leads to a shortening of distal phalanx, sacrifice of the whole toe and poor appearance after repair. The hallux nail flap is considered to be the best to treat this kind of injury. However, the traditional wrap-around flap excises the toe in a large range and has many complications in the donor site. In April, 2010, a case of degloving injury of the distal thumb was repaired with a combined wrap-around flap of the hallux nail flap and the tibial flap of the second toe. The patient was followed-up for 10 years in our hospital. Both of the appearance and function of the patient's thumb are well recovered.

Objective:To investigate the clinical efficacy of external fixators combined with anterolateral thigh musculocutaneous flap for treatment of Gustilo type IIIB/C open tibiofibular fractures.Methods:A retrospective case series study was conducted to analyze clinical data of 15 patients with Gustilo type IIIB/C open tibiofibular fractures admitted to Ruihua Hospital of Soochow University from March 2016 to June 2019. There were 11 males and 4 females, with the age of (48.5±12.6)years (range, 22-67 years). All patients underwent emergency debridement in stage I, the major blood vessels, nerves and tendons were inspected and repaired, and the fracture ends were fixed by external fixator. There were different degrees of wounds necrosis, infection and bone defect after operation. After debridement in stage II, the soft tissue defects with the dimension of 10.0 cm×5.0 cm to 30.0 cm×8.0 cm were repaired with anterolateral thigh musculocutaneous flaps whose areas ranged from 10.5 cm×5.5 cm to 30.5 cm×8.5 cm. All donor areas of the musculocutaneous flaps were sutured directly in stage I. The healing of the donor areas and musculocutaneous flaps were observed within 2 weeks after operation. At the last follow-up, the shape and sensory recovery of the flap, healing of fractures and related complications were observed. The lower extremity functional scale (LEFS) was used to evaluate the injured limb function.Results:All patients were followed-up for 12-32 months [(22.0±5.8)months]. All donor areas were healed by first intention, leaving only linear scars. The musculocutaneous flaps survived completely in all patients. Partial necrosis of large area of musculocutaneous flap occurred in 2 patients, and healed after debridement and skin grafting. Another patient had vascular crisis after musculocutaneous flap operation and survived after the embolized vein repaired by contralateral great saphenous. At the last follow-up, the shape of flap recovered well, and the feeling partially recovered with the two-point discrimination of 18-26 mm. All fractures healed well, and there were no serious infection-related complications such as osteomyelitis. The LEFS score was 47-69 points [(59.0±9.5)points].Conclusion:Theexternal fixator combined with anterolateral thigh musculocutaneous flaps for treatment of Gustilo type IIIB/Copen tibiofibular fractures can better restore the appearance of soft tissue defect of the lower leg, and can effectively reduce the occurrence of severe infection-related complications.

Objective:To investigate the clinical effect of flow-through anterolateral thigh perforator flap with fascia lata for repairing dorsal wounds of the hand and foot with extensor tendon defects.Methods:A retrospective case series study was conducted to analyze the clinical date of 14 patients with hand and foot wounds associated with extensor tendon defects admitted to Ruihua Affiliated Hospital of Soochow University from January 2015 to December 2019. There were 13 males and 1 female，aged 10-57 years［（39.2±13.4）years］. The wounds were all single with the area of 10 cm×4 cm to 23 cm×12 cm，including 8 wounds on the back of the hand and 6 wounds on the back of the foot. There was 1 patient accompanied with 1 tendon defect，10 with 4 tendon defects and 3 with 5 tendon defects，with the length of tendon defects ranging from 2.0 to 6.0 cm［（3.8±1.4）cm］. The dimension of flaps ranged from 12 cm×5 cm to 23 cm×13 cm，with the fascia lata from 11 cm×5 cm to 20 cm×7 cm. The deficient extensor tendons were repaired with the fascia lata and vascular pedicles were anastomosed by flow-though. A bilobed flap was harvested in 3 patients and a single flap in 11 patients. Donor sites were sutured directly. The survival of the flap and healing of the donor area were detected after operation. The extremity revascularization and shape and sensation recovery of the flap were measured at the last follow-up. The upper extremity functional evaluation standard set up by Hand Surgery Society of the Chinese Medical Association and Maryland foot functional score were used to evaluate the hand and foot function before operation and at the cast follow-up，respectively. The donor site complications and performance of tendon release or flap thinning in the second stage were recorded.Results:All patients were followed up for 8-30 months［（15.3±6.2）months］. All flaps survived successfully，with wounds and thigh donor areas healed by first intension. No significant effect of revascularization was observed on recipient sites，and acceptable cosmetic outcomes and sensation recovery of the flap were achieved at the final follow-up. For patients with dorsal wounds of the hand，the extensor function recovered in different degrees，and the flexion activities of the fingers were not limited. The total active movement was 180°-250°［（226.3±21.7）°］at the last follow-up，compared to preoperative 110°-170°［（145.6±13.2）°］（ P<0.01）. According to the upper extremity functional evaluation standard，the function was excellent in 4 patients，good in 2 and fair in 2. For patients with wounds of the foot，the flexion and extension function was good，with no obvious deformity of toes，and the Maryland foot functional score ranged from 60 to 92 points［（76.0±12.7）points］at the last follow-up，significantly improved from preoperative 18-45 points［（27.4±7.8）points］（ P<0.01），including excellent results in 2 patients，good in 3 and fair in 1. Only linear scars were left in the thigh donor area，and there was no discomfort such as scar contracture or pain. Four patients underwent skin flap thinning at 4-8 months after operation and none underwent a tenolysis. Conclusion:Repair of dorsal wounds with extensor tendon defects of the hand and foot by flow-through anterolateral thigh perforator flap with fascia lata can reduce interference to recipient sites and repair wounds and extensor tendons simultaneously，which can obtain good flexion and extension function and minor damage to the donor area.

Objective: To investigate the clinical effects of extra-long lateral femoral supercharged perforator flaps in repair of ankle and foot wounds. Methods: From March 2014 to October 2018, 16 patients with foot and ankle injuries were admitted to our hospital and left large area of wounds on foot and ankle after emergency treatment. There were 13 males and 3 females, with age of 27 to 60 years. The area of the wounds ranged from 14 cm×10 cm to 40 cm×17 cm. The wounds were repaired with extra-long lateral femoral supercharged perforator flaps. The widths of flaps in 8 patients were longer than 8 cm, and the bilobed flaps were designed to repair the wounds. The area of the flaps ranged from 12 cm×5 cm to 40 cm×9 cm. During the operation, 54 perforators were detected, with an average of 3.2 perforators in each flap, and 36 source arteries of perforators were detected. The blood vessel trunk of 15 patients was descending branch of the lateral femoral circumflex artery, and their supercharged mode was anastomosis of the bulky perforator of descending branch of the lateral femoral circumflex artery with the oblique branch of the lateral femoral circumflex artery and/or medial femoral circumflex artery or the descending branch of superficial illiac circumflex artery. The blood vessel trunk of 1 patient was oblique branch of the lateral femoral circumflex artery, and the supercharged mode of the patient was anastomosis of the oblique branch of the lateral femoral circumflex artery with the bulky perforator of the descending branch of the lateral femoral circumflex artery. The wounds were covered with the flaps after supercharged blood vessel anastomosis, and blood vessels in the donor sites were anastomosed with those in the recipient sites. The donor site was sutured directly. The survival of the flap after the operation and healing time of the wound, and the flap condition, the two-point discrimination distance of flap in patients who were reconstructed with sensation, the recovery of the ankle function, and the appearance of the donor site during follow-up were recorded. Results: A total of 17 flaps in 16 patients were designed, including 8 bilobed flaps and 9 non-lobulated flaps. Sixteen flaps in 15 patients survived. Vascular crisis occurred in the flap of one patient, and the flap survived when the vascular crisis was relieved by the second operation. The healing time of foot and ankle wounds ranged from 12 to 90 days. All the lateral femoral donor sites healed completely. During follow-up of 8 to 48 months, flaps in 2 patients were slightly bloated and were trimmed in 6 months after the operation. The other flaps were with good appearance, soft texture, good elasticity, and no rupture or ulceration. The two-point discrimination distances of flaps ranged from 7 to 16 mm in 8 patients who were reconstructed with sensation, and the other flaps recovered protective sensation. The flexion and extension function of ankle joint recovered well, and the walking function was not affected significantly. All donor sites formed linear scar, with no deep tissue infection such as osteomyelitis. Conclusions The application of extra-long lateral femoral supercharged perforator flaps to repair the large area of wounds in foot and ankle can significantly reduce damage to donor sites and has advantages of rich blood supply and good safety, thus it has satisfactory clinical effects.

Objective: To explore the clinical effect of bilateral anterolateral thigh flaps in repairing complex wounds of foot and ankle. Methods: From April 2014 to June 2017, 16 patients with complex foot and ankle wounds were treated in Ruihua Hospital Affiliated to Soochow University. There were 15 males and 1 female, aged from 12 to 73 years. Two of them had two wounds for each, the area of which was from 4 cm ×5 cm to 6 cm×10 cm. Fourteen cases were single-wounds, the area of which ranged from 11 cm×8 cm to 42 cm×15 cm. According to the wound surfaces, the wide wound cloth was divided into two pieces of cloth with a width less than 8 cm. The double-leaf skin flap was designed at the point of the perforating branch of the skin flap located by B-ultrasound on the iliac-patellar connecting line of the donor area. The course of the origin artery of the skin perforating branch of the skin flap was observed by DSA image. If the perforating branch of the double-leaf skin flaps was the common origin artery, the two adjacent wounds would be repaired directly. If the perforator of the double-leaf skin flaps is not the common artery, the double-leaf skin flaps were cut separately. After the pedicle division, the perforator vessels of the high perforator skin flaps were anastomosed with the distal end of the medial circumflex lateral femoral artery of the low perforator skin flaps to form a new parallel double-leaf skin flaps, which were then assembled or lobed to the recipient area. Flap donor sites were sutured directly. Results: 11 cases were repaired with parallel bilateral anterolateral thigh flaps with double perforators, and 5 cases were repaired with new parallel bilateral thigh flaps formed by anastomotic bridging of perforator vessels. The area of the flaps ranged from 5 cm×6 cm to 8 cm×22 cm. All the 16 flaps survived and the donor site wounds healed in one stage. Five cases underwent internal fixation removal and skin flap thinning 6 to 10 months after operation. Follow-up for 6 to 18 months showed that the skin flaps were of good color and texture, and the sensation of the flaps ranged from S1 to S3. Linear scars were left in all donor sites and lower limb movements were normal. Conclusions It is a good method to repair complex foot and ankle wounds with bilateral anterolateral thigh flaps, and it has the advantages of flexible design, less damage to donor site and good blood supply of the flap.