Formation of dermal collagen fiber is a complicated and sequential process with the progressive assembly of collagen. Collagen monomers form stepped and orderly protofibrils through longitudinal displacement. Subsequently, protofibrils or protofibrils and collagen are bonded by covalent bonds to form orderly lamellar structure of collagen fibers. Then collagen fibers are tightly wound into coarse collagen fiber bundles by covalent crosslinking. Decorin is a multifunctional small leucine-rich proteoglycan. It can prevent the aggregation of protofibrils by binding to the specific site of collagen with its core protein, and adjusting the spacing between the protofibrils with its glycosaminoglycan chain. Thus, by effecting the formation of collagen fibers with regulation of collagen assembly, decorin may help prevent scar formation and even promote regeneration.
Collagen ; Decorin ; metabolism ; Extracellular Matrix ; Extracellular Matrix Proteins ; metabolism ; pharmacology ; Fibrillar Collagens ; metabolism ; ultrastructure ; Fibrin ; metabolism ; Humans ; Microfibrils ; metabolism ; Proteoglycans ; metabolism ; pharmacology

Objective To explore the feasibility of the perforator-based intermediate dorsal pedal flap with vessels of cutaneous nerve nutrition for repair of soft tissue defects of the forefoot.Methods A retrospective case series study was performed for seven cases of soft tissue defects of the forefoot hospitalized between February 2013 and January 2017.There were five males and two females,with a mean age of 38 years (range,18-73 years).Injury regions were lateral plantar skin defect in the forefoot in three cases,dorsal skin defect in the third webbed toe in two cases and proximal dorsal skin defect in the fourth toe in two cases.The defect area was about 2.5 cm × 1.5 cm-4.5 cm × 2.0 cm.The perforator-based intermediate dorsal pedal flap with vessels of cutaneous nerve nutrition was designed on the lateral dorsum of the foot and then was incised and transferred to repair the forefoot wound based on its surgical anatomy.The time of surgery and the amount of intraoperative blood loss were recorded.An observation was done on feeling,appearance,texture,blood supply and survival of the flap as well as swelling,hypertrophic scar,itching,paralysis of the skin grafting area.The recovery of the activity function was assessed by American Orthopedic Foot & Ankle Society (AOFAS) score.Results The surgery time was 1.0-1.5 h (mean,1 h),and intraoperative bleeding was about 50 ml (range,30-100 ml).Seven cases of perforator-based dorsal medial skin flap with vessels of cutaneous nerve nutrition all survived,with early wound healing.After 2 to 15 months follow-up,two-point discrimination of flaps was 9-15 mm(average,12.5 mm).Skin flaps were with excellent texture and without swelling,the color of which was close to normal color with good appearance.The postoperative foot did not have bone resorption,wound infection,tendon adhesion,line-type or flaky scar left locally,lower limb walking dysfunction or other complications.Patients were satisfied with the functions of donor and recipient sites and the appearance of the flap.Conclusions Perforation-based dorsal flap with vessels of cutaneous nerve nutrition has high survival rate,satisfaction of appearance and fast recovery of recipient site,with no obvious foot pain,limitation of joint movement or other complications,and therefore is a reliable method to repair soft tissue defects in forefoot.

Objective: To investigate the morphological characters of the dorsal perforators originated from the deep palmar arch, so as to provide anatomic basis for V-Y advanced perforator flap. Methods: The following contents were investigated in 30 adult hand specimens perfused with red latex under surgical magnifier: ①The origin, courses, branches and distribution of the dorsal perforators originatedd from the deep palmar arch. ②The characters of anastomosis among the dorsal perforators, the dorsal carpal and metacarpal arteries. Mimic operation was performed on another fresh specimens perfused with red latex. Results: There were three perforators originated from the deep palmar arch, which passed through the 2nd-4th dorsal interossei and then divided into an ascending branch and a descending branch at the dorsum of hand. Then the ascending branch anastomosed with the dorsal carpal artery, and the descending branch stretched to the 2nd-4th dorsal metacarpal arteries. The originating outer diameters of the 1st-3rd perforators were (1.1±0.2) mm, (0.9±0.3) mm and (0.7±0.1) mm respectively, and the length of the stems were (1.1±0.3) cm, (1.0±0.2)cm and (0.9±0.1) cm respectively. Conclusions The V-Y advanced perforator flap with the dorsal perforator of the deep palmar arch as its vascular pedicle could be used to repair the dorsal carpal or dorsal metacarpal soft tissue defects.

Objective To explore the anatomical characteristics of mediate dorsal pedal cutaneous nerve and its nutritional vessels to provide anatomical basis of the perforator pedicle flap based on the medial dorsal pedal neurocutaneous vessels for repairing the forefoot soft-tissue defects.Methods From December,2016 to April,2017,the following contents were investigated in 30 adult feet specimens perfused with red latex:①The course,branches and distribution of the medial dorsal pedal cutaneous nerve.②The origin,course,branches and distribution of the nutrient vessels of the medial dorsal pedal neurocutaneous vessels.Mimic operation was performed on 1 fresh specimen.Results ①The mediate dorsal pedal cutaneous nerve mainly arose from the medial branch of the superficial peroneal nerve and processed forward for a distance of (2.5±0.4) cm under the surface of the inferior extensor retinaculum,and then divided into the mediate dorsal branch,the 1st and 2nd dorsal metatarsal branch over part of the dorsal pedal and digital skin.②The medial dorsal pedal neurocutaneous vessels were multiple segmental and polyphyletic,mainly include dorsalis pedis artery proximal perforator,the first metatarsal proximal perforator,the tibial proper plantar digital artery of the great toe and the perforater of the second toe web artery,of which the first metatarsal proximal perforator was most associated with operating methods.The first metatarsal proximal perforator perforate through the deep fascia to the subcutaneous area within the range of 1.0-2.0 cm near the proximal first plantar gap,the piercing point of which on deep fascia was constant,and the anatomical plane of the first metatarsal proximal perforator was higher than that of both the perforator of the toe web artery and the tibial proper plantar digital artery of the great toe.The first metatarsal proximal perforator divide into a large number of branches,which closely anastomose with adjacent perforators and other medial dorsal pedal neurocutaneous vessels.③Simulated surgery showed that the first metatarsal proximal perforation pedicle flap to meet the forefoot soft tissue defect repair.Conclusion The first metatarsal proximal perforator is constant in piercing point and reliable in blood supply,and it have a higher anatomical plane than that of both the perforator of the toe web artery and the tibial proper plantar digital artery of the great toe.The first metatarsal proximal perforator-based medial dorsal pedal neurocutaneous vascular flap can be transferred to repair the soft-tissue defects of forefoot.

Objective:To investigate the efficacy of a novel self-designed skin-stretching device for skin-soft tissue defects and bone exposure after internal fixation of calcaneal fracture.Methods:From July 2018 to January 2021, 9 patients were treated at Orthopedic Hospital, Southeast Hospital Affiliated to Xiamen University for skin-soft tissue defects and bone exposure after internal fixation of calcaneal fracture. They were 6 males and 3 females, aged from 19 to 61 years (mean, 42.6 years). The interval between their initial internal fixation and the present operation ranged from 14 to 75 days (average, 47.3 days). Of them, one developed wound dehiscence due to fat liquefaction, 2 necrosis of skin and soft tissue along the wound edges, and 6 incision infection. Their fusiform skin and soft tissue defects had formed after routine expansion of the wound, with an area of 5.0 cm×2.0 cm to 7.0 cm×3.5 cm, and all their wounds were positive by Pinch test. After a Kirschner wire with a diameter of 2.0 was placed on both sides of the wound, our novel self-designed skin-stretching device was installed. Intraoperatively, depending on the soft tissue conditions on both sides, the wound was closed acutely by about 5 mm in width. The threaded rod of the skin-stretching device was adjusted every day after operation to gradually reduce the wound surface until the wound edge was closed and sutured without tension. During wound stretch, the visual analogue scale (VAS), wound approaching time, stretch speed, wound healing time, complications and the Vancouver Scar Scale (VSS) for the wound scar at the last follow-up were recorded.Results:All the 9 patients were followed up for 8 to 18 months (average, 12.5 months). The wounds were successfully closed in all the patients. The time for wound closure (till the suture) ranged from 8 to 15 d, averaging 12.1 d; the stretch rate from 1 to 3 mm/d, averaging 2 mm/d; the time for complete wound healing (to the suture removal) from 22 to 30 d, averaging 26.8 d; the VAS score during the stretch from 3 to 7 points, averaging 4.9 points; the VSS score from 2 to 7 points, averaging 4.1 points. There was no recurrence of surgical site infection, skin re-necrosis or reoperation in the patients.Conclusions:In the treatment of skin-soft tissue defects and bone exposure caused by various reasons after internal fixation of calcaneal fracture, our novel self-designed skin-stretching device is an effective in situ wound repair instrument, showing advantages of simple operation, less trauma and high safety. It is suggested that the stretch speed should average 2 mm/d, which is well tolerated by patients.