RU2747694C1 - Method of skin and bone reconstruction of the finger of the hand and the guide for its implementation - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: method of skin and bone reconstruction of the finger of the hand consists in using the following guide and cortical-spongy avascular allograft. In the projection of the radial artery, a skin-fat flap of the required size is formed, taking into account the length of its vascular pedicle, with the preservation of the intermuscular septum and septal vessels throughout its entire length, as well as its connections with the radial artery and the periosteum of the radial bone. Then the radial artery is mobilized distal and proximal to the flap, maintaining vascular connections with the periosteum in the area of the proposed border osteotomy of the radial bone. Then the tissues are mobilized along the back and palmar surface of the radial bone in the area of graft collection. In the area of the proposed osteotomy, the palmar part of the guide is applied along the palmar surface of the radial bone in such a way that its central axial hole coincides with the palmar surface of the radial bone, while the intermuscular septum is located in a continuous slot of the palmar part of the guide. Then, in the same way, the back part of the guide is applied to the bone along the back surface, combined with the first one and connected with the help of retainers. The proximal end of the guide is fixed temporarily to the bone with spokes. The radial artery is located on the lateral surface of the guide. Next, with an oscillatory saw, by tightly pressing its blade to the groove of the guide to ensure the prevention of damage to the intermuscular septum with septal and periosteal vessels, connecting cuts of the palmar and back cortical plates are performed, forming a border blood-supplied bone autograft of the navicular shape, connected by septal and periosteal vessels with the radial artery and skin flap. The length of the blood-supplied autograft corresponds to the length of a similar finger of a healthy hand minus the length of the nail plate, the width corresponds to 1/3 of the diameter of the radial bone at the site of its collection, and the thickness is similar to the thickness of the radial bone in the donor area. Then the radial artery is bandaged and crossed proximal to the guide. After that, the spokes are removed, and the parts of the guide are separated from the radial bone in turn, which allows one to preserve the integrity of the intermuscular septum. Then, on the cortical-spongy allograft, a flat platform is formed for the installation of the guide, after which the guide is applied in assembled form and fixed to the allograft platform with spokes. Then, an allograft corresponding to the blood-supplied autograft in shape, direction of the cut plane, length, thickness, but exceeding it in width by 0.5 cm, taking into account the subsequent partial resorption of the avascular graft, is cut out of the cortical-spongy allograft with an oscillatory saw through the guide groove. After that, the avascular bone allograft is transferred to the border defect of the radial bone, completely combining the planes of the cutouts of the allograft and the radial bone. Then preventive bone osteosynthesis of the radial bone is performed with a plate with screws proximal and distal to the border defect and the location of the plate on its palmar surface. After that, the blood-supplied radial bone graft, together with the skin flap, is transferred on the vascular pedicle, represented by the distal part of the radial artery, to the position of the lost finger. Then osteosynthesis of the stump of the finger and the blood-supplied graft is performed with spokes. Next, the soft tissues of the finger are formed from the skin ray flap, after which the donor wound on the forearm is sutured. The guide for longitudinal shaped osteotomy during the collection of the autograft of the radial bone and during the formation of a cortical-spongy non-vascular allograft to replace the resulting border defect of the radial bone contains a groove for installing the saw blade and a central axial hole and consists of two equal combined separable parts, the palmar and back. The guide is made individually according to computed tomography data using 3D printing, depending on the planned size of the graft, so that the guide is at least 1 cm longer than the planned graft at the distal end, and at least 2.5 cm longer at the proximal end. The axial hole precisely corresponds to the external surface of the radial bone in the area of formation of the planned graft. The groove for the saw blade is made of a navicular shape. In the middle, in the area of the distal end of the guide, a continuous slot with a width of 2 mm is made to accommodate the intermuscular septum and the vessels contained therein. At its proximal end, a connecting element of the “protrusion-groove” type and two holes for the spokes are made.

EFFECT: inventions make it possible to achieve a precise correspondence of the blood-supplied graft to the specified dimensions of the bone skeleton of the reconstructed finger of the hand, to minimize the donor bone defect of the radial bone and to reduce the risk of its pathological fracture.

2 cl, 4 dwg

Description

The group of inventions relates to medicine, namely to reconstructive surgery of the hand.

In order to reconstruct a lost finger, a technique is most often used, including the formation of a skin-bone blood-supplied autograft of the radial bone, bone grafting of the resulting defect in the donor site, the formation of a finger from the blood-supplied graft (N.M. Aleksandrov, S.V. Petrov. bone reconstruction of fingers using blood-supplied grafts / Modern technologies in medicine, 2011, no. 4, pp. 22-27).

For the prevention of pathological fracture of the radius during the reconstruction of the finger of the hand with a skin-bone blood-supplied autograft, a method of strengthening the radius is known, which consists in the formation of a rectangular incision during the collection of a skin and bone graft of the radius and its preventive bone osteosynthesis with fixation with a plate and screws (Bowers J KW, Edmonds , Girod DA, Jayaraman G., Chua CP, Toby EB Osteocutaneous radial forearm free flaps. The necessity of internal fixation of the donor site defect to prevent pathological fracture // J. Bone Jt. Surg. 2000. Vol. 82-A, No. 5. P.694-704.). However, the method has the following disadvantages:

- a rectangular cut is formed, which significantly reduces the strength of the bone due to the presence of two areas of stress concentration in the corners of the cut;

- it is difficult to calculate the coinciding lines and the plane of the osteotomy along the dorsal and radial surfaces of the bone, in connection with which an uneven plane of the bone cut is formed and tight uniform contact (contact) between the graft and the radius is not achieved along the entire plane of the cut, which lengthens the time of consolidation and restructuring of the graft; there is a high probability of the formation of bone undercuts, which can cause an increased concentration of stresses and cause a sharp decrease in bone strength;

- There is a high probability of damage to the radial artery, as well as the periosteal and septal vessels due to the possible slipping of the saw blade from the rounded surface of the bone;

- It is difficult to form a blood-supplied radial graft of a given size and shape in each case.

As a prototype, a method for preventing a fracture of the radius during plasty with a "Chinese" flap was chosen, which strengthens the donor site when performing reconstruction of a finger of the hand (RF patent No. 2506053 dated 02/10/2014). The method consists in the formation of a triangular notch when taking the graft and replacing the marginal defect of the radius with a rhomboid cortical allograft, the ends of which are embedded in the medullary canal, and the expanded part is located in the region of the apex of the notch.

However, the method has the following disadvantages:

- the defect of the radius is not fully replenished, which prevents its organotypic restoration;

- an uneven plane of the bone cut is formed, there is a high probability of the formation of undercuts, which can cause an increased concentration of stresses and cause a decrease in bone strength;

- there is a high probability of damage to the radial artery and septal vessels, as well as disruption of the blood supply to the graft during osteotomy;

- it is difficult to dose the depth of the incision, as well as to form a blood-supplied radial bone graft of a given size and shape;

- the method does not provide sufficient strength of the bone during its twisting and stretching.

In order to perform precision osteotomy, with smooth transitions without undercuts, which can cause an increased concentration of stresses, guides are used.

Known guide for performing osteotomy of the radial bone, which is made on a 3D printer and used to collect blood-supplied autograft (Nevedrov A.V., Shibaev E.Yu., Kalensky V.O., Zadneprovsky N.N., Shishkin V.B. , Sharifullin F.A.K., Tsoi O.A., Lazarev M.P., Ivanov P.A., Rybinskaya A.L.Experience in the use of vascularized bone grafts for the treatment of nonunited fractures and bone defects of the extremities / Transplantology. 2019. T. 11.No. 1.P. 9-20). However, it has the following disadvantages:

- does not provide precision osteotomy, as it is positioned taking into account the anatomical landmarks of only one side of the radius;

- there is no possibility of preserving the intermuscular septum with septal and periosteal vessels in the osteotomy area;

- does not allow precise metering of the depth of the marginal cut of the bone;

- there is no possibility of performing a precision transverse osteotomy, which increases the risk of cuts formation during saw blade oscillations and a decrease in the strength of the donor site;

- does not provide stable fixation to the bone, which leads to displacement of the guide when the saw blade oscillates.

As a prototype, the "Saw guide for osteotomy" was selected, which contains a body equipped with a through groove, a lamellar pad with a stop and a hole on the fastening part. With the working end and the handle, the body is movably connected to the plate cover by means of an angle bracket with arcuate grooves, in which locking screws and nuts are located, while the corner bracket, at one end, with an arcuate groove, contacts the stop and is located on the fastening part of the plate cover, in the hole of which a locking screw is installed, the other end with an arcuate groove is connected to the body, the body is made with a central axial hole in which a locking screw is installed, and the through groove of the body is oriented to the working end of the plate lining (RF Patent No. 159058 dated 05/13/2015). However, this guide has the following disadvantages:

- does not provide the possibility of performing a precision marginal figured and longitudinal osteotomy, corresponding in shape to the bone framework of the lost finger;

- does not allow to preserve the integrity of the intermuscular septum with septal and periosteal vessels in the osteotomy area;

- it is necessary to perform a complete transverse osteotomy without a guide, followed by immersion of the lamellar lining in the interfragmental gap, which increases the trauma of bone tissue, increases the risk of formation of cuts during primary osteotomy;

- there is no possibility of fixing the guide to the bone tissue, which increases the risk of its displacement during saw blade oscillations;

- does not ensure the preservation of bone continuity;

- does not allow metering the depth of the marginal cut of the bone.

The task of the proposed group of inventions is to improve the method and develop a device to eliminate the shortcomings of the prototype.

EFFECT: achieving precise correspondence of the blood supplied graft to the given dimensions of the bone frame of the reconstructed finger, minimizing the donor bone defect of the radial bone, reducing the risk of its pathological fracture.

The technical result is achieved by the fact that in the method of skin and bone reconstruction of a finger of the hand, including making a figured cut when collecting an autograft of the radius and replacing the marginal defect of the radius with an allograft, the blood-supplied graft is formed in a scaphoid shape while preserving the intermuscular septum with septal and periosteal vessels using the proposed made using additive 3D printing technologies so that the length of the blood-supplied graft corresponds to the length of a similar finger of a healthy hand minus the length of the nail plate, the width corresponds to 1/3 of the radius of the radius at the site of its collection, and the thickness is similar to the thickness of the radius in the area of the donor site , the resulting marginal defect of the radius is replaced with a cortical-cancellous avascular allograft formed using the proposed guide, which is 0.5 cm greater than the width of the blood-supplied bone graft.

A guide for implementing the method of skin and bone reconstruction of a finger of a hand, containing a groove for installing a saw blade and a central axial hole, is made individually according to computed tomography data using 3D printing, depending on the planned size of the graft, so that the guide is longer at the distal end than planned graft by at least 1 cm, in length at the proximal end - at least 2.5 cm, consists of two equal parts, palmar and dorsal, the axial hole precisely matches the outer surface of the radius in the area of the planned graft formation, a groove for the canvas The saw is made of a scaphoid shape, in the middle in the region of the distal end of the guide there is a continuous slot 2 mm wide to accommodate the intermuscular septum and the vessels contained in it, in its proximal end there is a protrusion-groove type connecting element and two holes for the spokes.

The claimed method and guide is illustrated by the attached graphic materials, where

FIG. 1. Palmar and back of the guide.

FIG. 2. Assembled guide.

FIG. 3. The guide is fixed to the radius with the preservation of the intermuscular septum with the septal and periosteal vessels.

FIG. 4. The blood-supplied bone graft was moved to the position of the first finger on the distal part of the radial artery, an avascular allograft was transplanted into the donor bone defect and fixed with wires, bone osteosynthesis of the radial bone was performed with a plate.

The guide is a personalized device, rectangular in shape, for longitudinal shaped osteotomy, which is made according to computed tomography data using 3D printing, depending on the planned size of the graft. The length of the guide at its distal end is greater than the length of the planned graft by 1 cm or more, at the proximal end by 2.5 cm or more, and the width (transverse dimension in the frontal plane) and thickness (anteroposterior dimension in the sagittal plane) are more than 0.5 cm on each side. The guide consists of two equal parts, palmar 1 and dorsal 2, and its inner surface precisely matches the outer surface of the radius in the area of the planned graft formation. The scaphoid groove 3 for the saw blade corresponds to the dimensions (length, thickness, width) of the planned graft. Along the entire length of the guide, there is a central axial opening 4 corresponding to the shape of the radius in the area of the planned graft collection. In the middle, in the region of its distal end, there is a continuous slot 5 2 mm wide to accommodate the intermuscular septum and the vessels contained in it. In the proximal end of the guide, there is a connecting element 6 of the "protrusion-groove" type, and also two holes 7 for the wires are made, which are used for temporary intraoperative fixation of the guide to the radial bone (Fig. 1.2).

The proposed method is carried out as follows.

Before the operation, after the clinical and radiological diagnosis has been established, computed tomography of the forearm and the injured hand is performed when scanning with a minimum step (no more than 1 mm) of the coordinate table in high-resolution mode with the patient in a stationary position throughout the acquisition of a complete set of tomograms. From the array of tomographic data, information is selected by setting the cutoff level, setting the intensity gradient factor empirically, information for restoring the image of the forearm bone structures of a certain density. At the stage of preoperative planning, the area of collection and the required dimensions of the displaced marginal radial graft are determined. The place of graft collection is determined taking into account the planned length of its vascular pedicle. Graft dimensions: length - corresponds to the length of a similar finger of a healthy hand minus the length of the nail plate; width - corresponds to 1/3 of the diameter of the diaphyseal part of the radius at the place of its collection; thickness - similar to the thickness (anteroposterior dimension in the sagittal plane) of the radius in the area of the donor site. Then, using hybrid parametric modeling, topological optimization and additive 3D printing technologies, with the aim of precision collection of the scaphoid form of the marginal radial graft with the dimensions specified at the stage of preoperative planning and subsequent alloplasty of the donor defect, the proposed guide for osteotomy is made. During the operation, in the projection of the radial artery 8, a skin-fatty flap 9 of the required size is formed, taking into account the length of its vascular pedicle while preserving the intermuscular septum 10 and septal vessels along its entire length, as well as its connections with the radial artery and the periosteum of the radial bone. Then the radial artery 8 is mobilized distal and proximal to the flap 9, while maintaining vascular connections with the periosteum in the area of the proposed marginal osteotomy of the radial bone. After that, tissues are mobilized along the dorsal and palmar surfaces of the radius in the area of graft collection. In the area of the proposed osteotomy along the palmar surface of the radius, the palmar part 1 of the guide is applied so that its central axial hole 4 coincides with the palmar surface of the radius. In this case, the intermuscular septum 10 is located in the continuous slot 5 of the palmar part 1 of the guide. Then, in the same way on the back surface, the back part 2 of the guide is applied to the bone, aligned with the first and connected with the help of clamps 6. The proximal end of the guide is temporarily fixed to the bone with wires using holes 7. The radial artery 8 is placed on the lateral surface of the guide (Fig. 3 ). Next, with an oscillator saw, by tightly pressing its canvas against the groove 3 of the guide to ensure the prevention of damage to the intermuscular septum 10 with the septal and periosteal vessels, the cuts of the palmar and dorsal cortical plates are connected to each other, forming the marginal blood-supplied bone graft 11 connected by the septal and periosteal vessels radial artery 8 and skin flap 9. Then bandage and cross the radial artery 8 proximal to the guide. After that, the needles are removed, and parts 1 and 2 of the guide are alternately separated from the radius, which allows maintaining the integrity of the intermuscular septum. Then a flat area is formed on the cortical-cancellous allograft for placing the guide. After that, the assembled guide is applied and fixed to the allograft site with pins passed through the holes 7. Then, from the cortical-cancellous allograft with an oscillator saw through the slot 3 of the guide, the avascular bone allograft 12 is cut out, corresponding to the blood-supplied graft in shape, direction of the plane of the cut, length, thickness , but exceeding it in width by 0.5 cm, taking into account the subsequent partial resorption of the avascular graft. Thereafter, the avascular bone allograft 12 is transferred to the marginal defect of the radius. In this case, the planes of the cutouts of the allograft 12 and the radius are completely and precisely aligned. After that, the avascular bone allograft 12 is tightly pressed against the defect of the radius and fixed with wires. Then perform prophylactic osteosynthesis of the radial bone with a plate 13 with the provision of screws proximal and distal to the marginal defect and the location of the plate on its palmar surface. After that, the blood-supplied radial bone graft 11, together with the skin flap 9, is transferred on the vascular pedicle, represented by the distal part of the radial artery 8, in the position of the lost finger. Then the osteosynthesis of the finger stump and the blood-supplied graft is performed with wires. Next, the soft tissues of the finger are formed from the radial skin flap 9 (Fig. 4). After that, the donor wound on the forearm is sutured. The hand and forearm are fixed with a plaster cast for 1 month.

Clinical example.

B-a S., 25 years old, was in the clinic of the Federal State Budgetary Educational Institution of Higher Education "PIMU" of the Ministry of Health of Russia regarding the stump of the first finger of the left hand at the level of the base of the main phalanx, the stump of the second finger at the level of the head of the main phalanx, leading to contractures of the first metacarpal bone. The patient was injured at work on 06/07/19 when her left hand fell under the rolls of the processing machine. When the patient was admitted, the soft tissues of the first toe were formed and the soft tissue defect on the stump of the second toe was replaced by plasty with a non-free inguinal axial skin-fat flap (06/13/19). At the next stage on February 10, 20, the bone-skin reconstruction of the first finger of the left hand was performed by moving the skin-bone radial flap on the peripheral vascular pedicle. Before the operation, the required dimensions of the bone skeleton of the restored finger, the length of the vascular pedicle of the graft were determined, computed tomography of the bones of the forearm and the injured hand was performed. After that, using hybrid parametric modeling, topological optimization and additive 3D printing technologies, a developed personalized osteotomy guide was made. During the operation, the radial artery with a skin-fatty flap was mobilized while preserving the intermuscular septum with septal and periosteal vessels in the area of graft collection. The two parts of the guide are attached to the osteotomy area and are connected to each other. Then the guide was fixed in a single block to the area of collection of the radial bone graft with wires. In this case, the intermuscular septum with septal vessels is laid in a continuous slot of the guide, the radial artery is located on its lateral surface. A marginal scaphoid osteotomy of the radial bone was performed using a guide. As a result, the integrity of the septal and periosteal vessels extending from the radial artery and adequate blood supply to the graft are preserved. Using the same guide, an avascular cortical-cancellous allograft was cut out, corresponding in length, thickness, direction of the notch plane and shape to the formed marginal defect of the radial bone and the formed blood-supplied graft, but exceeding it in width by 0.5 cm. The avascular allograft was laid in the defect of the radial bones and fixed with knitting needles. The blood-supplied radial bone graft, together with the skin flap, is moved to the stump of the first metacarpal bone and the first toe is formed. The postoperative course is smooth. The wounds healed by primary intention. The skin flap has completely engrafted, which indicates the preservation and functioning of the septal vessels. 2 months after the operation, there are clear signs of radial bone graft consolidation, which indicates the preservation of the periosteal vessels and its blood supply. The marginal avascular bone graft of the radius is completely congruent to the defect and adheres tightly to it. In the long-term postoperative period, no pathological fracture of the radius was revealed; signs of consolidation and restructuring of the avascular graft were noted.

The advantages of the method.

A blood-supplied skin and bone graft of the radial bone of the specified exact dimensions and the required shape is formed individually for each patient.

An avascular bone cortical-cancellous allograft is formed, which exactly matches the shape and direction of the plane of the incision to the marginal defect of the radius formed after taking the blood-supplied graft.

When using the guide, the exact coincidence of the cuts on the dorsal and palmar surfaces of the radius is ensured, which ensures the formation of a flat plane of the marginal incision of the radius, as well as an avascular bone graft used to replace the defect.

Exact coincidence of the size and shape of the cutout of the avascular allograft and the marginal cut of the radial bone, as well as the formation of a flat surface of the marginal cut and the graft, ensures their tight contact over the entire contact surface and optimal conditions for consolidation and restructuring of the avascular allograft and increasing the strength of the radius.

The developed guide allows you to preserve the integrity of the intermuscular septum with the septal and periosteal vessels in the osteotomy area, form an adequately blood-supplied graft, and reduce the risk of damage to the radial artery.

The developed method of skin and bone reconstruction of a finger using a guide makes it possible to form a scaphoid graft, which improves the cosmetic results of the operation and reduces the likelihood of a pathological fracture of the radius.

When using a guide, prevention of damage to the radial artery is ensured, since it is well visualized and fixed during manipulation on the bone, and the likelihood of the saw blade slipping off the rounded surface of the bone is also reduced.

The presence of a continuous slot on the guide and its two-module design ensure prevention of damage to the septal and periosteal vessels during positioning and fixation of the guide before performing an osteotomy.

Claims (2)

1. A method of skin and bone reconstruction of a finger of the hand, which consists in using a guide according to claim 2 and a cortical-spongy avascular allograft, in the projection of the radial artery, a skin-fat flap of the required size is formed, taking into account the length of its vascular pedicle while preserving the intermuscular septum and septal vessels along its entire length, as well as its connections with the radial artery and periosteum of the radial bone, then the radial artery is mobilized distal and proximal to the flap, while maintaining vascular connections with the periosteum in the area of the proposed marginal osteotomy of the radial bone, then the tissues are mobilized along the dorsal and palmar surfaces the palmar part of the guide is applied so that its central axial hole coincides with the palmar surface of the radius, while the intermuscular septum is placed in the continuous slot of the palmar part of the guide spruce, then in the same way on the back surface, the back of the guide is applied to the bone, aligned with the first and connected with the help of clamps, the proximal end of the guide is temporarily fixed to the bone with needles, the radial artery is placed on the lateral surface of the guide, then with an oscillatory saw, by pressing it tightly cloths to the groove of the guide to prevent damage to the intermuscular septum with the septal and periosteal vessels, the interconnecting cuts of the palmar and dorsal cortical plates are made, forming the marginal blood-supplied bone autograft of the scaphoid shape, connected by the septal and periosteal vessels with the radial artery and the length of the cutaneous flap autograft corresponds to the length of a similar finger of a healthy hand minus the length of the nail plate, the width corresponds to 1/3 of the radius of the radius at the site of its collection, and the thickness is similar to the thickness of the radius in the donor area. th area, then bandage and cross the radial artery proximal to the guide, then remove the needles, and also separate parts of the guide from the radial bone one by one, which allows maintaining the integrity of the intermuscular septum, then on the cortical-cancellous allograft form an even platform for installing the guide, after that the guide assembled, apply and fix to the allograft site with needles, then from the cortical-spongy allograft with an oscillator saw through the slot of the guide, cut out the allograft corresponding to the blood-supplied autograft in shape, direction of the cut plane, length, thickness, but exceeding it in width by 0.5 cm s taking into account the subsequent partial resorption of the avascular graft, after which the avascular bone allograft is transferred to the marginal defect of the radius, completely aligning the planes of the cutouts of the allograft and the radius, then prophylactic bone osteosynthesis is performed from the radial bone with a plate with screws proximal and distal to the marginal defect and the location of the plate on its palmar surface, after which the blood-supplied radial graft together with the skin flap is transferred on the vascular pedicle, represented by the distal radial artery, in the position of the lost finger, then osteosynthesis of the stump is performed finger and blood-supplied graft with needles, then the soft tissues of the finger are formed from the radial skin flap, after which the donor wound is sutured on the forearm. 2. A guide for longitudinal figured osteotomy when collecting an autograft of the radius and when forming a cortical-cancellous avascular allograft for replacing the formed marginal defect of the radius, containing a groove for installing a saw blade and a central axial hole, characterized in that it consists of two equal combined detachable parts, palmar and dorsum, the guide is made individually according to computed tomography data using 3D printing, depending on the planned size of the graft, so that the guide is at least 1 cm longer than the planned graft at the distal end, and not less than 1 cm in length at the proximal end. less than 2.5 cm, the axial hole precisely corresponds to the outer surface of the radius in the area of the planned graft formation, the slot for the saw blade is made of a scaphoid shape, in the middle in the area of the distal end of the guide there is a continuous slot 2 mm wide to accommodate the intermuscular The ectopic septum and the vessels contained in it, a protrusion-groove connecting element and two holes for the spokes are made at its proximal end.

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