| BackgroundHand is not only a working and sense organ, but also people’s "second face". Lose whole or part of a finger would defect appearance and function of the hand, afect patient’s life and even disturb their mental health. How to cure trauma and recover function of hand is still a problem for microscopic surgeons. As the rise of microsurgical technique in the 1960s, Dongyue Yang.etc completed the second toe transfer for reconstruction of the thumb for the first time in 1966. In 1968, Cobbertt use the great toe to reconstruct thumb. In 1980, Morrison use thumbnail flap to reconstruct thumb. Toe transplantation is the most popular thumb reconstruction operation methods for which can reconstruct a thumb with good shape, function and sensation. However, the second toe tend to be very different in morphology and functionin from normal fingers:About the structure of bone and joint, toe is smaller than finger, it’s nail is shoter, the end of toe looks like a mallet, metatarsophalangeal joints is hyperextension and the interphalangeal joints are hypereflexion at rest position. From the perspective of aesthetics, if simplely transplant second toes to hand, it looks like an artificial deformity, its difficult to for patient to accept the urgly shape. Therefore, how to reconstruct a thumb with good shape, enough length and good function is always a difficult problem. For hand Surgeon, many experts has focus on how to improve the appearance of reconstructed thumb. Wei (1996), Koshima (2000), Wei Wang and Guoliang Cheng has introduced some method from different aspects, these methods just to improve the shape of the second toe, not change bone and joint structure defects of the second toe. The difference of structure between toe and finger determines that second toe transplantation cannot make a finger with perfect appearance and function. Among these improved operation of reconstruction, the combined reconstruction makes best effect, which can make a finger with ideal length, shape and function. Foucher (1980) first applied the method of twist to finger combied reconstruction. According to this concept, Jia Zhong (1985), Tsai (1990), Koshima (1994) use operation method of "nail and skin flap of the great toe unite tendon and joint combination of the second toe" to make the new reconstituted thumb with good appearance and better Joint range of motion. But this operation has not been widely applied for many years, the main reason is that the combined reconstruction is a large project to unite nail flap of the great toe and bone and joints of the second toe, including the intricate structure of skin, blood vessels, bone and joint. This operation is extremely complex; operation time is long, and with high risk. It not only needs high level of microsurgical technique, but also need rich experience and high sense of responsibility, thus greatly restricted the combined reconstruction in the clinical application and promotion.We rely on a large number of successful thumb combinations, innovatively applied combined reconstruction operation for finger reconstruction. We break through the limitation of length less and ugly appearance of the second toe, overthrow the conception of proximal interphalangeal joint defect finger can’t be reconstructed. Using the thumbnail flap unites bone and joint combination of second toe successfully rebuilt fingers defecte on different plane. The reconstructed long finger’s length, thickness, joint location, nail is almost as same as normal finger. A large number of successful cases of the surgery, good operation effect, make us at the international leading level in the field of thumb reconstruction regardless of the quantity and quality. There are still a lot of problems waiting to solve about long finger combined reconstruction in clinical, such as the control of shape, the structure of the bone and joint, blood vessels choose and collocation problom, the blood supply of composite tissue flap.etc, further anatomy research was needed in order to improve the effect of surgery. As the constant innovation of scientific research and the rapid development of computer technology, digital medical technology in multiple disciplines such as head and neck, limb, heart, stomach.etc, in various fields such as preoperative planning, surgical simulation, clinical teaching and training is widely used and recognized, greatly promote the development of related discipline. As the most commonly used methods to collect medical data, spiral CTA has regular popularization and application, complex structure and various density can be obtained quickly by volume scanning form. With more and more advanced 3D image reconstruction software can build high quality 3D digital model, anatomical structure and the relationship between the various groups can be 3D dynamically displayed. In the field of microscopic reconstructive surgery, how to follow the development trend of digital technology, give full play to the huge potential application in the field of digital medicine in microscopic reconstruction, reduce the difficulty of the combined reconstruction "big project", promote the thumb reconstruction, is an important topic urgently need to be solved.Objective1. To solve the complicated anatomy problem of full-length finger reconstruction, including control reconstructed finger’s shape, bone and joint structure, the relationship between various vessel types of tissue flap, collocation and blood supply problems, etc, research these problem step by step, in order to make the operation design more rational and more perfect.2. All specimens perfused with gelatin-barium sulfate, the CTA data processed by MIMICS 10.013D reconstruction software, explore standard digital model of combined reconstruction of full-length finger, in order to accurately simulate and demonstrate the operation process of finger reconstruction, improve and programme optimal operation scheme according to the related clinical anatomy, make a good prospective study for the clinical application of the digital model.3. Choose Ⅳ, Ⅴ and Ⅵ degrees finger defect cases, preoperative angiography and CTA scan were performed, using image reconstruction software MIMICS10.01 to build combined reconstruction digital model personally for patients with long finger defect to optimize the operation scheme, accurate preoperative design, and solve the problem of that the operation is complex and design of the combin reconstruction is not precise enough, blindness, at high risk, to make the operation design more accurate and easy to control, obtain perfect appearance and good function of combined reconstructed fingers, promote the operation through digital teaching and clinical training.Materials and methods1. Clinical applied anatomyTwenty expanded wrap-around great toe flaps and vascularized second toe joints taken from human cadavers foots were studied using three methods:latex perfusion for microanatomy analysis, denture material and vinyl chloride mixed packing for cast analysis, and Gelatin-barium sulfate perfusion for Micro-CT arteriography.2. Establishment of cadaveric digital model of Composite Tissue GraftingIn this study, ten adult fresh hands and two feet cadavers were filled with Gelatin-barium sulfate. And then cadavers perfused with Gelatin-barium sulfate were performed CT scan to obtain tomographic images and stored in DICOM format. Apply Mimics 10.01 software for three-dimensional reconstruction models, Geomagic Studio 12 to optimize the model, finally stored in STL format. Secondly import Mimics to show complete 3D model. By defining different organizations threshold, we finished the skin reconstruction, blood vessels and bone reconstruction, muscle reconstruction and composite tissue reconstruction, respectively. In Mimics software, we can display multiple 3D model of construction simultaneously. We can adjust the transparency of the model to achieve multiple spatial perspectives to determine the anatomical relationship of blood vessels, joint and skin. We also may move and rotate the model to achieve the desired effect.In Mimics software, we simulated the surgical procedure of cosmetic reconstruction of the full digits in the hand by Composite Tissue Grafting. The basic steps are as follows:1) Rebuilt 3D model of hand and foot cadaveric specimens with Gelatin-barium sulfate perfusion.2) Design the reconstituted fingers and enlarge 10% of the skin in the 3D reconstruction model. And then 3-D print the skin in order to design the wrap-around flap;3) The skin defect were made transparent, and to overlap with donor area of great toe. Marked the proximal incision of wrap-around flap and determined the length of the flap. Edited and cut wrap-around bone flap model with fibular digitil hallucis artery and made it transparent;4) Edited and cut the second toe bone and joint with tibial digital artery, first dorsal metatarsal artery and first plantar metatarsal artery.5) Second toe PIP joint takes place of index finger PIP joint, giving priority to the MTP joint. Wrap-around flap replaced the reconstituted nails; finally, overlay the transparent wrap-around bone flap model with the joint model;6) The proximal and distal ends of the second interphalangeal joint performed autogenous iliac grafts fixed with intersect Kirschner pins or Mini-plate. Assessed the relative position of arteries;7) Designed the artery anastomosis plan and determined the position and length of arteries according to the relationship between arteries of wrap-around bone flap and the arteries of joint.8) Complete digital wrap-aroud bone flap and composite bone and joint model9) 3D Print the wrap-around flap and vascularized second toe joint model3. Clinical application of digital model for combined reconstructionFrom March 2013 to December 2015,14 patients underwent vascularized Composite Tissue Grafting for reconstruction of finger defect. There were eight men and six women, with an average age of 26 (range,17-45 years). The patients had no contraindications for arteriography and made iodic allergic test. Trocar lien 22 G was anterogradly puncture in the dorsalis pedis artery, Use German Ulrich binocular high-pressure syringe to inject iodixanol injection (16 g:50 ml Visipaque injection). Iodixanol, Physiological saline 1:1, dose (diluted) adult 15 ml, injection speed (adult) 1.5 ml/s. After injection of contrast agent 2 s it began dynamic volume scanning. Image center of Shandong provincial hospital CT scanner (320 rows of Toshiba Aquiline one) and GE image post-processing works tation (GE AW 4.4) were applied to scan foot of patients with enhanced volume. The steps to CT scanning are as follows:Place the patient in a supine position with Bend knees bend as well as foot flat. When scanning the object being measured brake, the Angle of the scanning plane at 0 DHS; Scanning scope of 16 cm length, including the dorsalis pedis artery distal to the toes of hiking. Scan parameters:voltage 100 kv (70 kv) children, current 35 MAs; Scanning layer thickness/distance of 0.5 mm/0.5 mm. According to the wild (FOV) is 120 mm-120 mm; Scan cycle 0.35 s/r, inspection and post-treatment time about 30 to 35 minutes. Three-dimensional spiral CT scans data was saved in a disc in DICOM format. Elbow vein angiography was performed to CT scanning for hand.3.1 Establishment of full finger digital model of Composite Tissue Grafting Gave the patients CT scan to obtain tomographic images and stored in DICOM format. Apply Mimics10.01 software for three-dimensional reconstruction models, Geomagic Studio 12 to optimize the model. The image segmentation, and the reconstruction methods of the skin blood vessels and composite tissue were the same as the cadaveric 3-dimensional reconstruction, the basic steps of establishment of full finger digital 3D model can refer to the relevant content of the chapter two.3.2 Surgical Technique for full-length finger reconstruction. Full-length finger reconstruction consists of composite tissue reconstruction as follows: 1. Thumbnail flap for the reconstructed, length finger skin,nail and partly phalangette including most nails of the great toe, bone of Phalangette fibular side, superficial peroneal nerve, deep peroneal nerve, superficial vein Phil side Plantar digital artery and nerve 2.vascularized second toe joint, including middle and proximal phalanx, proximal interphalangeal joint with or without MTP and head of metatarsal bone, Flex/ Extensor tendons, toe dorsal vein, tibial Plantar digital artery and nerve,superficial peroneal nerve, deep peroneal nerve and tongue-shaped flap. The surgical design and procedure can refer to the relevant content of the chapter twoResults1. Applied anatomical study1.1 The first dorsal metatarsal artery was located between the first dorsal interosseous muscle and the first metatarsal rather than through the muscle, which anastomosed with the first plantar metatarsal artery at the bottom of the first toe web and divided into the great toe fibular artery and the second toe tibial artery. These two digital arteries exist constantly, and their diameter changed along with the first dorsal metatarsal artery.1.2 By the local anatomy and CT and Micro-CT scanning after sub-nanometer barium sulfate spiral perfusion, we studied the blood supply of the second metatarsal head carefully. Three main arteries nourished the area from metatarsal head to the neck: the second plantar metatarsal artery from the plantar side, the second dorsal metatarsal and the first dorsal metatarsal artery nourished the metatarsal head from both sides. The second plantar artery branch reached the metatarsal head by the sub-head way, all the three nutrient arteries stretched out communicating branches to each other at the metatarsal neck, and the artery branches to distal or dorsal side were periosteal artery or nutrient artery. The nutrient arteries arranged from anterior inferior to posterior to the starting nodular of the collateral ligament, which distributed deeply into the metatarsal head with the branch. The branches from the first and second dorsal metatarsal artery to dorsal metatarsal neck formed the arterial ring; there were artery branch or blood vessel chain traveling from metatarsal head to metatarsophalangeal joint on both sides, and connected with digital arteries from proximal phalanx. When we flipped the metatarsal head to improve the flexion of the metatarsophalangeal joint, some protection should be taken for the blood supply according to the vascular distribution.1.3 The second plantar metatarsal artery obliquely across the neck under the flexor tendon, which divided into the second toe fibular artery and the third toe tibial artery, was the main and most constant continuity of the second toe fibular artery.1.4 There were superficial and deep veins contributed to the venous system of the second toe, and the deep veins went along accompanying its corresponding artery. The deep veins continued with the superficial through the communicating branch at the first toe web, which could drainage the venous from the toe flap.1.5 About an average of 9.8° axial tilt to the fibular side could be observed between the proximal interphalangeal joint and proximal phalanx articular surface of the second toe, which should be taken into account when reconstruction.2. Digitized samples model for digital reconstructionTen feet and two hand specimens were scanned by spiral CT after gelatin barium sulfate infusion. The complex three-dimensional anatomical relationship of the foot arteries and muscles, bones, could be observed according to the precise high spatial resolution scanning tomographic image data acquired from the three-dimensional helical CT. Besides some thick branches of the dorsal metatarsal artery and plantar metatarsal artery at the metatarsal heads, even the feeding artery, could be exhibited.In this study, a clear three-dimensional image was reconstructed using the MIMICS 10.01, an useful three-dimensional image reconstruction software, with the personal computer. By the reconstruction of the three-dimensional digital model of the phalangeal joint of the second toe and the valva of wrap-around in reconstruction of digits, we could the observed the relations of the arteries, bone and joint and the three-dimensional structure of skin clearly, plan and design the important structure in advance, such as the arteries and bones. As the three-dimensional image could not rebuilt the nerve, as well as the poor exhibition of the veins, the nerve and vein were excluded from the digitized model of the specimens, only the arteries could be observed in the combination of the phalangeal joint of the second toe and the valva of thumb nail.3. Clinical application of digitized samples model in digital reconstructionCompared to the traditional elbow venous catheter angiography, dorsal artery angiography can clearly show small vessels in the extremities such as fine branches of the dorsal metatarsal artery and plantar metatarsal artery, even the little branches of the digital arteries could be observed clearly. And the dynamical image of the artery at different time phase could be observed by volume scanning. Consistency could be tested not only between the solid anatomical data of the digitized model and the anatomical structure observed in the process of reconstruction, but also in the construction of the digitized model and the reconstruction of digits. We implemented the preoperative digitized virtual model of reconstruction of digits and optimized the operation program in all the 14 cases in our group. All the reconstructed full-length fingers survived in the first stage, and no vascular crisis occurred. Twelve fingers were followed up for 5 to 31 months after operation, and the excellent and good rate was 93.5%. The average operation time were 6.6 hours, which was significantly shorter, compared with 7.5 hours of traditional group?Conclusions1. Clinical anatomy and operation design of full-length finger combined reconstruction1.1 Prevent metacarpophalangeal joint’s hyperextension deformity of the reconstructed full-length fingerNormal second metatarsophalangeal(MTP) joint’s flexion angle is usually 45°, extension Angle is 90°. And metacarpophalangeal(MP) joint’s flexion angle is usually 90°, extension Angle is 30°. Turn head of metatarsal bone can correct plantar toe joint’s hyperextension in order to improve its function. The angle head of metatarsal bone need to turn is:MTP’s flexion Angle minus MP’s extension Angle. According to the head of second metatarsal bones’nourish blood vessels are mainly distributed to the metatarsal side of the starting point of the lateral collateral ligament, to ensures good blood supply of plantar bone and meet the requirements of bone cutting Angle, dorsal osteotomy position shoud be close to the starting point of the lateral collateral ligament proximally, plantar side utmost tilt proximally according to flip Angle.1.2 Blood supply problems1.2.1 Blood vessels reverse problem:The first dorsal metatarsal artery (FDMA) and the first plantar metatarsal artery (FPMA) communicate at first toe web space, give rise to Plantar di gital artery at fibular side of the great and the tibial side of the second toe, then turn to the lateral side of the toe, when the thumb nail flap wrap the second toe joints up (twist) these two vessels change of courts, free end of the short arteria digitalis inevitably forced to rotated, when these two connected arteria digitalis pull straight the rotated angle can be up to 360°, the first plantar artery is also affected. Vascular rotated makes it easy to vascular crisis. We sutured each vessel respectively to reduce vascular crisis. This topic discusses article relationship in the first toe web space, and the anatomical basis for vessel collocation and anastomosis.1.2.2 Blood supply of second toe nail skin flap and bone and joint:After cut out thumb nail flap and bone and joint of the second toe, the most commonly used repair method is to reconstruct a new great toe by cover the donor site of the great toe with fibular side nail bone flap of the second toe. To ensure blood supply of the second toe’s nail flap, pay attention to avoid damage the the second dorsal metatarsal artery (SDMA) or the second pavimentum metatarsal artery (SPMA). When second toe’s MTP transplanted its blood supply come from FDMA, we should keep it connect with FDMA to avoid dorsal digital arteries and its branch injury. If the second toe’s fibular side arteria digitalis come from SPMA, keep MTP on SDMA, this can protect the metatarsal neck artery ring and ensure metatarsal head’s blood supply. If there was a thick deep vein, it can be as the current return circuit to simplify the operation. 2. Optimization of perfusion and radiographic techniques2.1 With sub-nanometer barium sulfate can perfuse foot vessals and its micro-branchs well. CTA or MICRO-CT scans can achive continuous 3D image of tiny blood vessels, its anatomy data totally conform to traditional anatomy data, but the perfusion pressure and quantity may affect the diameter of vessels.2.2 For foot small blood vessel detection, dorsalis pedis artery puncture angiography is better than cubital vein angiography. It can meet the needs of thumb reconstruction. It use less contrast medium and has less complication.3.Clinical significance of the digital model of full-length finger combined construction Full-length finger combined reconstruction digital model can display the 3D anatomical relationship between foot arteries and surrounding structure, can realize virtual demonstration procedure and accurate optimization design, change subjective blindly estimate, avoid blindness detect combination of vessel and skin, improve certainty and controllability of the operation, reduced the operation complexity and difficulty, improve the operation efficiency and success rate, reduce the operation risk and shorten the operation time, make a complex full-length fingers reconstruction operation standardization and accurate, has important guiding significance to the clinical operation. Establish specimens and vital thumb combined reconstruction digital model database can rich digital anatomy study, promote and improve the teaching and training process, increase communication between doctor and patient. The model based on convenience personal computer platform, has important practical significance to the development and popularization of the finger reconstruction. |
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