RU2515391C1 - Calcaneal implant - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: calcaneal implant is presented in the form of a solid structure of a porous NiTi reinforced plate and consists of a horizontal platform and a vertical rod. The vertical rod is presented in the form of a parallelepiped and separates the horizontal platform on a posterior shoulder and an anterior shoulder. The posterior shoulder has a length less than that of the anterior shoulder, and a transverse through canal, which is connected with two holes perpendicular thereto. The anterior shoulder has a width and height decreasing to an end face step-like. The horizontal platform has grooves formed along its lateral areas, and a number of through holes arranged along the edges of the lower and upper plates. The through holes are inserted into the groove.

EFFECT: more effective rehabilitation and reduced length of treatment of the patients after the partial and total calcaneal resection by replacing the calcaneal or its defect using the porous NiTi implant.

2 ex, 9 dwg

Description

The invention relates to medicine, namely to traumatology and orthopedics, and can be used for reconstruction of the hindfoot after partial or complete resection of the calcaneus.

Calcaneal resection is not a popular, but a necessary measure in patients with osteomyelitis, tumors. Removal of the calcaneus, even partial, significantly reduces the support ability of the limb, leads to the development of deforming arthrosis of the joints of the foot and ankle joint, the development of pain.

Osteoplastic reconstructive operations aimed at restoring foot support, improving walking function in 30.2-47.9% of patients are ineffective. The rehabilitation period after surgical treatment is at least 2 years.

There is a method of reconstruction of the hindfoot in the absence of the calcaneus (patent for the invention of the Russian Federation No. 2457804, 08/10/2012), which consists in arthrodesis of the ankle and talar-navicular joints in the position of the displacement of the forefoot posterior to the contact of the cuboid bone with the tibia and overlapping of the last ram-navicular articulation. Fixation of the arthrodesis segment is carried out in the apparatus of G.A. Ilizarov.

The disadvantage of this method is the change in the stereotype of movements in connection with arthrodesis of the ankle joint, shortening of the foot, shortening of the length of the limb due to wedging of the tibia into the talus.

There is a method of reconstruction of the calcaneus after resection of its anterior and lower segments (article Brinker M.R., Loncarich P.P. Melissinos E.G., O'Connor P.P. Calcaneogenesis. J Bone Joint Surg [Br] 2009; 91-B: 662-5). The proposed method is implemented in several stages. At the first stage, the pathological lesion is resected, the anatomical and topographic relationships are restored by dosed traction in the transosseous apparatus. In the second stage, the forefoot is moved posteriorly, bringing the cuboid bone under the tibia, and the calcaneal tubercle is displaced posteriorly and upward, arthrodesis is performed using an allograft from the cancellous bone. Compression between the abutting bones and fixation of the segment is carried out using a transosseous apparatus. In case of failure of ankylosing of joints, the third stage, using intraosseous tightening screws and an osseous S-shaped bracket, provides immobilization and compression of abutting bones, creating favorable conditions for ankylosing of joints. The duration of treatment is 15 months.

The disadvantage of this method is the duration of treatment, shortening of the foot, ankylosing of the ankle joint, deformation of the distal foot, flat feet. When using the proposed method, it is impossible to replenish a fully resected calcaneus. The degree of risk and invasiveness of surgery increases due to the need to take the graft from the iliac crest.

Closest to the claimed is a method of treating calcaneus osteomyelitis (patent for the invention of the Russian Federation No. 2407469, 12/27/2010). A bone cement implant formed at the polymerization stage in accordance with the shape and size of the bone defect is placed in the calcaneus defect formed after necrosecvestrectomy. After stopping the purulent process and healing trophic wounds, the implant is removed, replacing the defect with an autograft. Immobilization is carried out by a plaster cast.

The disadvantage of this method is the lack of functional loads, including axial, within 10-15 months, which can lead to contracture of the ankle joint, foot joints, flat feet. Insufficient stabilization in the bone defect of the bone cement implant can lead to its migration. The displacement of the calcaneal tuber is not excluded under the influence of traction of the calf muscles. The reconstruction of the calcaneus in two stages, against the background of trophic changes in the soft tissues, can lead to the formation of long-term non-healing ulcers in the area of surgical access. An autograft when replacing an extensive defect of the calcaneus against the background of circulatory disorders can be lysed.

The objective of the invention is to increase the effectiveness of rehabilitation and reduce the treatment time for patients after partial and total resection of the calcaneus by replacing the calcaneus or its defect with an endoprosthesis made of porous titanium nickelide.

The task is achieved by the calcaneus endoprosthesis, made in the form of an integral structure of a workpiece of porous titanium nickelide reinforced with a plate of titanium nickelide. The endoprosthesis consists of a horizontal platform and a vertical shaft. In this case, the vertical rod is made in the form of a parallelepiped and divides the horizontal platform into the rear shoulder and front shoulder. The back shoulder has a length shorter than the length of the front shoulder, and a transverse horizontal through channel that connects to two holes perpendicular to it. The front shoulder has a width and height, stepwise decreasing towards the end. The horizontal platform has grooves formed along its side platforms and a series of through holes located along the edges of the lower and upper platforms, and the through holes extend into the grooves.

The novelty of the device.

1. The implementation of the endoprosthesis in the form of an integral structure from the workpiece of porous titanium nickelide with a reinforced plate of titanium nickelide strengthens the structure and ensures the stability of the structure to significant alternating loads.

2. The shape of the endoprosthesis is made in the form of a horizontal platform and a vertical rod. In this case, the vertical rod is made in the form of a parallelepiped and divides the horizontal platform into the rear shoulder and front shoulder. The shape of the endoprosthesis is close to the shape of the calcaneus, which optimally ensures the distribution of vertical axial loads and the normal anatomical and topographic relationship of the bones of the foot and lower leg. The vertical shaft provides with arthrodesis of the calcaneus-talar joint an increase in contact with the talus and stabilization, and when replacing a defect of the calcaneus provides support for the articular site.

3. The implementation of the front shoulder of a horizontal platform with a width and height that decreases stepwise to the end allows to reduce the invasiveness of the operation, to ensure the implantation and fixation of the front shoulder of the endoprosthesis in the bone, which improves the stabilization of the structure and improves the conditions for the growth of surrounding tissues in the pores of the endoprosthesis.

4. The transverse horizontal through channel in the back shoulder of the endoprosthesis allows you to fix the Achilles tendon.

5. The grooves made along the side platforms of the horizontal platform can reduce the tension of the ligaments when they are fixed to the place of attachment.

6. Holes located along the edges of the lower and upper platforms extending into the grooves allow the ligamentous apparatus to be fixed in a position close to the anatomical one.

The technical result of the invention is to achieve:

- stability of the structure to significant alternating loads;

- distribution of vertical axial loads and normal anatomical and topographic relationships of the bones of the foot and lower leg;

- stabilization of the design and improvement of the conditions for the germination of surrounding tissues into the pores of the endoprosthesis;

- fixation of the Achilles tendon;

- reduce the tension of the ligaments when they are fixed to the place of attachment;

- fixation of the ligamentous apparatus in a position close to the anatomical;

- with arthrodesis of the calcaneus-talar joint, increased contact with the talus and stabilization;

- when replacing the calcaneus defect of the support of the articular site.

The invention is illustrated by the drawings shown in Fig 1-9:

Figure 1. Calcaneus endoprosthesis in isometric view.

Figure 2. Appearance of the calcaneus endoprosthesis in isometric view.

Figure 3. Calcaneus endoprosthesis (side view).

Figure 4. Calcaneus endoprosthesis (top view).

Figure 5. Calcaneus endoprosthesis (cross-section along AA).

6. Calcaneus endoprosthesis (cross-section along BB).

7. Calcaneus endoprosthesis (longitudinal section along CC).

Fig. 8. X-ray photographs of a patient with endoprosthetics and arthrodesis of the tarsal joints with a post-resection defect of the calcaneus.

Fig.9. X-ray photograph of a patient with calcaneal fistulonecresecrectectomy and endoprosthetics.

The calcaneus endoprosthesis is made in the form of an integral structure of a porous titanium nickelide preform with a through porosity of 60-70%, which was obtained by high-temperature self-propagating synthesis reinforced with a titanium nickelide plate 1. The endoprosthesis includes a horizontal platform 2 and a vertical rod 3 perpendicular to it. Rod 3 has the shape of a parallelepiped with rounded corners and edges, and the quadrangular cross section of the vertical rod is smaller than the horizontal platforms minutes and a vertical rod 3 positioned symmetrically along a horizontal axis of a horizontal platform 2 and separates it into the front arm 4 and the rear arm 5, and the front shoulder length exceeds a length adjustable shoulder twice. The front shoulder 4 has a width and a height, stepwise decreasing towards the end and having the same length. The width of the first step 6 adjacent to the vertical rod corresponds to the width of the rear shoulder of the horizontal platform, and the height is reduced due to the lower slot 7, which starts from the ledge 8 and continues to the end 9 of the front shoulder. The width and height of the second stage 10 and third stage 11 of the front shoulder of the horizontal platform are reduced due to the side slots 12 and the upper slots 13. At the end of the rear shoulder of the horizontal platform in the transverse direction there is a through horizontal channel 14, which is connected to two holes 15 perpendicular to it, located symmetrically on the sides of the horizontal axis on the upper area of the back shoulder. Along the lateral platforms of the horizontal platform, grooves 16 are formed, which begin from the inlet holes in the channel of the rear shoulder and end at the second stage of the front shoulder of the horizontal plate, and are connected with through vertical holes 17 located along the edges of the upper and lower platforms of the horizontal platform.

The operation is as follows. Heel bone endoprosthetics using the proposed device can be performed in combination with arthrodesis of the heel and talus, heel and cuboid and cuboid navicular joints in patients after total removal of the calcaneus and concomitant deforming arthrosis of the intertarsal joints. During the installation of the endoprosthesis into the canal formed in the bones of the second row of the tarsus, the third step of the anterior shoulder of the horizontal plate is hammered in. A vertical rod is inserted into the canal made in the talus. The ends of the Achilles tendon are divided into portions, which are stitched, passed through the holes and the horizontal channel in the back shoulder, put into the groove and hemmed with duplicate to the main trunk of the Achilles tendon at the level of the opening of the upper platform of the posterior shoulder. Tendons of the long plantar muscle, lateral and deltoid ligaments are stitched in portions and removed through holes in the groove on the lateral surfaces of the horizontal platform of the endoprosthesis, orienting their position in accordance with the topography of attachment of the ligamentous apparatus of the foot and also stitching with duplicate to the corresponding ligaments. After installing the endoprosthesis, if necessary, skin plastic surgery is performed, the wound is sutured with drainage left and a removable splint is applied for the period until ankylosis of the arthrodesized joints. Drainage is removed after 1-2 days, the sutures are removed after 10-14 days.

An endoprosthesis can also be installed without arthrodesis of the intertarsal joints when replacing an extensive post-resection defect of the calcaneus, provided that the articular facets with the underlying bone are preserved, as well as the medial or lateral wall and calcaneal tuber with sufficient bone tissue for implanting the shoulders of the horizontal platform and the vertical shaft of the endoprosthesis with the purpose of ensuring its primary stabilization and growth into the porous part of the bone prosthesis. A fistulonecrectomy and replacement of the resected part of the calcaneus with an endoprosthesis is performed during a single intervention. Removal of the bone affected by the pathological process is as follows. During the pathologically altered portion of the cortical wall of the calcaneus, within the limits of a healthy bone, the cortical plate is opened and removed by folding. With the help of the osteotome and circular saw, the calcaneal tubercle is cut off and with the help of osteotomes, Volkman's spoons, the cancellous bone affected by the pathological process is removed. An endoprosthesis of the size corresponding to the defect is selected. In the calcaneal tubercle, in the anterior calcaneus and in the trabecular bone, grooves are formed under the calcaneal-talus joint for the insertion of the end elements of the anterior shoulder, posterior shoulder, and vertical shaft of the endoprosthesis.

Part of the front shoulder of the horizontal platform is inserted into the prepared groove in the anterior calcaneus, then the vertical shaft of the endoprosthesis is inserted into the corresponding groove, and the posterior shoulder is mounted on the calcaneal tubercle. Perform plastic surgery, choosing the most optimal option for plastic replacement of soft tissue defect depending on the size of the defect and the possibility of mobilization of flaps. End the operation by applying a spoke apparatus.

Example 1. Patient K. 24 years. In 2000, after a closed compression intraarticular fracture of the right tibia and right calcaneus was treated conservatively. In connection with suppuration of conflicts and hematomas, a fistulous form of calcaneus osteomyelitis developed. During 2001-2002 sanitation operations were repeatedly performed. Due to their inefficiency and septic complication, on July 6, 2003, an operation was performed to completely remove the calcaneus, after which the focus was stopped. On June 12, 2004, heel bone arthroplasty was performed, including arthroplasty of the intersublane joints. The postoperative period was uneventful. Axial loads are allowed 9 months after surgery. At the follow-up examination 5 years after the operation, the patient uses a cane during long walks, and moves indoors without auxiliary devices. There is no swelling in the foot and ankle joint, the postoperative scar is coarse, retracted. The range of motion in the ankle joint is within the "lower limit of normal: flexion-extension." Achilles tendon and calf muscles are elastic. The patient is satisfied with the result of treatment (Fig. 8)

Example 2. Patient D., 35 years old. He entered treatment 10.09.2006, with osteomyelitis of the left calcaneus. After a compression intraarticular fracture on 05.06.2005, an open reduction was performed, osteosynthesis with a plate. The plate was removed 3 months after surgery due to osteomyelitis. Anti-inflammatory treatment was ineffective. At the time of inspection on the plantar surface in the projection of the calcaneus is a fistula, a necrotic wound, the bottom of which is the calcaneus. After the examination, on September 15, 2006, a fistibulonecarservestectomy was performed with removal of the calcaneus body, the joint site was preserved. To replace the defect, a reinforced porous endoprosthesis is used, the dimensions of which are adapted to the dimensions of the defect. From the side of the lateral and plantar walls, lyophilized bone is laid. The soft tissue was plastic with a rotational two-lobed flap. After closure and suturing of the wound, a spoke-rod apparatus was applied in order to fix and access treatment, dressings. Spokes were drawn through the calcaneus: two along the contour of the articular surface of the calcaneo-talar joint and one along the plantar contour. The wounds healed after 1.5 months. The device was dismantled 6 months after surgery. During the control examination in 2008 (2 years after the operation) there are no walking disorders, the patient experiences minor inconvenience with the maximum axial load on the calcaneus due to postoperative scars, the longitudinal arch of the foot is reduced (2 degree flat feet), uses an insole arch support (Fig. 9).

Claims (1)

The calcaneus endoprosthesis, characterized in that it is made in the form of an integral structure of a porous titanium nickelide preform reinforced with a titanium nickelide plate and consists of a horizontal platform and a vertical rod, while the vertical rod is made in the form of a parallelepiped and divides the horizontal platform into the back shoulder and front shoulder moreover, the back shoulder has a length shorter than the length of the front shoulder and a transverse horizontal through channel that connects to two holes perpendicular to it, the bottom shoulder has a width and height that decreases stepwise toward the end, the horizontal platform has grooves formed along its lateral platforms, and a series of through holes located along the edges of the lower and upper platforms, and the through holes extend into the grooves.

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