Anatomy And Clinical Application Of Finger Side Quadrate Island Flap And Minisize Free Vein Skin Flap In The Repair For Digital Replantation With Skin Defect

Objective:In the clinical diagnosis and treatment process of hand surgery, there are increasing cases of finger amputation or digital circulation disfunction with soft issue defect due to different causes such as press injury, rotative tear injury, electric saw injury and heat press injury. All these cases are difficult to treat. Because replantation is hard to operate, and the lack of effective repair method to deal with the skin and vessel defect, finger shorten replantation or direct amputation operation were adopted generally in the past. These influence the appearance and function of hand severely and made huge pression to the patients' life and psychological aspect. Therefore to the cases of amputated fingers with comparably complete structures of bone and joint but defect of skin and soft tissues, it is necessary to keep the integrity of the fingers with some kind of repair methods designed according to the degree, position and area of damage and defect. The aim of our research is based on the research of applied anatomy of finger side quadrate island flap and minisize free vein skin flap, and is to further explore the replantation repair method for different kind of amputated fingers with skin and soft tissue defect using finger side quadrate island flap and minisize free vein skin flap, and to use the method in clinical appliances, for validating the feasibility and validity of replantation repair method with skin and soft tissue defect using finger side quadrate island flap and minisize free vein skin flap.Methods1. applied anatomy:1.1. Summarize vessel radiography and applied anatomic data in hand and understand the course and distribution of vessels and nerves in hand;1.2. Adopt five upper limb vessel-casting specimens, observe and summarize the course and distribution of vessels of hands and superficial veins in forearms directly;1.3. Adopt 10 fresh hand specimens from operation, observe the distribution, quantity and diameter of hypodermic veins, and perform vessel water test to observe the valve function of small veins.1.4. Adopt five upper limb specimens of adults fixed by formalin and one fresh damaged and abandoned hand. Dissect by layers; observe the course of superficial palmar arch, the distribution of common and proper digital arteries and nerves. Measure the distance from outlet point of superficial palmar arch (point a₁) and bifurcation point of common finger artery (point a) to fundus of terminal knuckle of index finger, meddle finger, ring finger and little finger (point C) respectively. Then measure the distance from three outlet points of common finger artery superficial palmar arch (point a₁)and bifurcation point of metacarpus head level (point a) respectively, according to the measurements of length of a₁-c and a-c, decide the location levels of every fingers could get;1.5. Choose 50 hand specimens, according to the body surface anatomic symbol, measure the distance of the furthest point C (fundus of terminal knuckle of index finger, medle finger, ring finger and little finger) of designable island flap to transfer axis point (common finger artery at metacarpus head bifurcation point A and common finger artery at superficial palmar arch outlet point a₁). Then measure if the length can get every finger location level from the transfer axis point according to the length of a₁-c and a-c;1.6. Choose 70 abandoned fresh finger specimens (15 index fingers, 20 middle fingers and 20 ring fingers, 15 little fingers). Design and cut 1.0cm×1.0cm and 2.0cm×2.0cm skin flaps from different area of ulnar side of index finger, both sides of middle finger and ring finger and radial side of little finger for different cases. Observe the number of veins and vein ends that can be anastomosed in the island flaps;2. Clinical research:13 fingers of 12 patients involved in this study, among which there were 10 fingers of 9 male patients and 3 fingers of 3 female patients. The age ranged from 16 to 48 years old, averagely 23.6 years old. Six fingers were completely amputated, and 7 fingers were partly amputated. The amputation location varied from the base of proximal phalanx to fundus of distal phalanx. Injury cause: 6 press injuries, 1 rotative tear injury, 2 electric saw injuries, 1 heat press injury, 1 electric injury and 1 chemic burning. There were skin and vessel defects existed after prophase treatment of debridement. According to different defect location, the skin defects could be divided into three kinds: palmar defect, dorsal defect and cricoid defect. Design different hand repair operation with finger side quadrate island flap and forearm minisize free vein skin flap according to the different defect types. Observe the survive condition of the flaps and amputated fingers after operation; observe the sense and function recovery situation of the fingers with a long-term follow up.Results1. applied anatomy:1.1. Understand the course and distribution of vessels and nerves of hand, especially common palmar digital artery and proper palmar digital artery. Hypodermal superficial vein flaps of distal end of forearm palmar side had characters as follows: the skin is thin; vein networks are abundant; hypodermal vein is superficial and fine, with similar diameters as digital vessels; the valve action of little veins is weak.1.2. Both anatomic measurement results of formalin-fixed upper limb sample and fresh abandoned hand specimen and measurement results of body surface symbol measurement of hands show that ulnar side of index finger, two sides of middle finger and radial side of little finger could reach the C point of thumb via ac transfer. Ulnar side flaps of ring finger can reach middle area of thumb via alc transfer. Middle finger flap can reach the further area of ring finger and little finger via ac transfer. Ulnar side flap of index finger can reach further area of middlephalanx of middle finger and little finger via ac transfer, and reach C point of middle finger and little finger via alc transfer. Radial side flap of ring finger can reach the further area of middle phalanx of index finger and middle finger via ac transfer. Reach C point of index finger and middle finger via a₁c transfer. Ulnar side of ring finger can only reach further area of middle phalanx of middle finger and proximal area of middle phalanx of index finger via ac and a₁c transfer. Both sides' flaps of ring finger can reach C point of little finger via ac and a₁c transfer. Radial side flap of little finger can reach further area of proximal phalanx of ring finger and proximal area of proximal phalanx of middle finger via ac and a₁c transfer. 1.3. cut 1.0cm×1.0cm finger side quadrate flaps which can contain over one palmar superficial vein(or 1 vessel end for anastomose use at each of distal and proximal side of flap), and/or over one finger dorsal superficial vein(or 1 vessel end for anastomose use at each of distal and proximal side of flap). cut 2.0cm×1.0cm flaps which can contain over 2 palmar superficial vein(or 2 vessel end for anastomose use at each of distal and proximal side of flap), and/or over 2 finger dorsal superficial vein(or 2 vessel end for anastomose use at each of distal and proximal side of flap).2. clinical research:13 fingers of 12 patients in this group all have survived successfully. The length did not shortened, the appearance were good. Artery flaps at late period had good appearance and good quality, vein flaps contracted with different degrees, with darker colors, harder textures and less elasticity. According to TAM functional assessment standard: 6 excellent, 5 good, 2 bad, the rate of excellent and good was 84.6%Conclusions1. Finger side quadrate island flap and forearm minisize free vein skin flap can be used in widespread area of for finger amputation with skin defect of different types.2. The operation design has advantages such as flexibility, safety, less damage, easy to control the operation method and large range of application and it is an ideal operation method of replantation repair for finger amputation with skin defects.