RU2702520C1 - Method of knee endoprosthesis replacement in patients with osteoporosis - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to traumatology and orthopedics, and can be used for prevention of development of early instability of knee joint endoprosthesis in patients with osteoporosis. Bone fragments of the condyles of the femoral and shinbone are pre-resected and milled into crumbs with particle size of 1.0 mm to 500 mcm. Composite is prepared from obtained autologous bone tissue by mixing with β-tricalcium phosphate in ratio 1:1. Produced mixture is used for plasty of all cavities, cysts, bone defects of femoral and shinbone bonesaw-lines, perforations and impressions. Endoprosthesis is implanted with the help of bone cement on a prepared bed of the femoral and shin bone.

EFFECT: method provides higher strength of the endoprosthesis fixation by filling the defects with a mixture of autologous bone tissue and β-tricalcium phosphate.

1 cl, 2 ex

Description

The invention relates to medicine, specifically to traumatology and orthopedics, and can be used to prevent the development of early instability of the knee replacement in patients with osteoporosis.

Osteoarthrosis and osteoporosis are the most important diseases of the musculoskeletal system in terms of their medical and social significance, which affect patients of an older age group. Among women older than 80 years, every second suffers from osteoarthritis and every second from systemic osteoporosis (Povoroznyuk V.V., Grigoryeva N.V., 2004).

Systemic osteoporosis was diagnosed in 14% of patients with gonarthrosis and in 25% with coxarthrosis (http://www.mif-ua.com/archive/article/34656). According to the researchers (Karvonen R.L., Miller P.R., Nelson D.A. et al., 1998), the bone mineral density measured in the knee joint area significantly decreases with the development of gonarthrosis. In the condyles of the femur and tibia, cavities filled with adipose tissue form, significantly reducing the strength of the bone tissue.

Endoprosthetics of the knee joint is the most effective method of relieving pain and restoring joint function in patients with end-stage gonarthrosis. However, against the background of an increase in the number of primary prosthetics, the number of cases of revision prosthetics due to early and late instability has increased. Provided that the prosthetics are technically correct, the achieved endoprosthesis design stability after a short period of time is unsuccessful due to a decrease in the strength of bone structures. The reaction of bone tissue to the implant in the form of stress remodeling, caused by the influence of factors such as micromotion, thermal necrosis and granulomatous reaction to metal methacrylate and metal ions, leads to enhanced resorption, reducing bone mass and creating prerequisites for fracture or instability of the prosthesis (Ternova N.K. , Bulych P.V., Vovk V.V., Tuz E.V., 2007).

These processes are especially pronounced in patients with osteoporosis. Makarov M.A., Makarov S.A., Pavlov V.P., Vardikova G.N. based on dual-energy X-ray densitometry, it was shown that the resorption around the endoprosthesis reaches its maximum by 6 months after surgery, and the loss of bone mineral density (BMD) around the acetabular component of the endoprosthesis reaches 20% (Stress remodeling of bone tissue after endoprosthesis replacement of large joints and its conservative correction / Modern Conservation rheumatology, No. 1, 2009).

Karyakina E.V., Gladkova E.V., Puchinyan D.M., Persova E.A. report, based on the study of bone remodeling markers, the predominance of resorption processes after hip replacement for up to 12-15 months in patients with osteoporosis (Remodeling of bone tissue after total endoprosthetics of men with osteopenia of different degrees of coxarthrosis / International Journal of Applied and Basic Research, No. 4 (part 3) , 2017).

Azizov M.Zh., Alimov A.P., Rustamova U.M., Yakubov F.U. showed in their study that even with osteotropic drugs in patients by 4 months after knee replacement, the rate of decrease in bone mineral density (BMD) only slightly slows down (Comparative evaluation of densitometric indicators against osteotropic therapy for knee replacement / Genius orthopedics, No. 1, 2016).

A known method of prosthetics of the knee joint with a defect is a niche on the articular surface (RF Patent No. 2316279,02.10.2008). The method includes transverse osteotomy of the articular surface of the tibia and the formation of a longitudinal channel in it, resection of the articular surfaces of the femur, applying bone cement to the inner surfaces of the components of the prosthetic knee joint and on the resected surfaces of the femur, tibia and installing prosthetic components on them and connecting them together characterized in that in the presence of a defect - a niche in the bone after resection of the articular part of it, an explant from pori is first introduced into the bone defect a strict titanium nickelide made with a flat surface and with a wedge-shaped shape on the opposite side, the explant surface size not exceeding the defect area and the height of the wedge-shaped part greater than the defect depth, while the implant is inserted into the bone defect by the wedge-shaped part until its upper surface is congruent with bone surface at the edge of the defect, then a layer of bone cement is applied to the explant.

The disadvantage of this method is the use of an additional metal structure, which does not lead to an improvement in the quality of bone tissue, but only fills a bone defect, around which processes of bone resorption against osteoporosis also occur over time.

There are also known methods for repairing condyles of the femur and tibia used in knee replacement, in which they are replaced with an autograft from sawdust and condyle from the iliac crest, such as:

A method for repairing tibial defects, including total knee replacement, graft formation, and a bed for it, characterized in that a radiograph draws a line along the edge of the defect, draws a perpendicular through its middle and determines the height of the condyle defect from the radiograph of the contralateral, intersect perpendicular to the axis of the lower leg the pineal gland so that the height of its medial part is equal to the height of the perpendicular restored from the defect, form a flat bed n the surface of the defect of the tibial condyle, the cut fragment is laid on the formed flat bed with the cut plane and fixed with its needles to the underlying bone, the edge of the graft is aligned with the outer edge of the defect, and the part of the graft protruding into the joint cavity is cut off along the section plane of the tibial condyles (RF patent No. 2200494 March 20, 2003).

A method for replacing extensive defects of the condyles of the femur and tibia during revision knee replacement, characterized in that the bone defect is filled with an orthotopic structural spongy-cortical allograft from the condyles of the femur or tibia, respectively, which is modeled at the site of placement during maternal surgery and box (RF patent No. 2355324, 05.20.2009).

The disadvantage of these methods is the limited choice of transplant size. In this regard, in the presence of extensive bone defects in area and extent, these methods are not technically feasible. Performing an autograft removal from the iliac crest through an additional incision increases the invasiveness of the surgical intervention, and therefore, increases the risk of postoperative complications. In the presence of cavities of complex three-dimensional shape, filling them with flat resected fragments completely and without voids is not possible.

A known method of replacing bone defects of the condyles of the tibia or femur with total knee replacement (patent No. 2465855.10.11.2012), including the implementation after resection of the condyles of the femur and tibia and the installation of the test components of the endoprosthesis of the condyle of the condyle of the condyles with bone-replacing material with a bone-replacing material, the condyle of the bone without a bone defect performs its sawdust 2-6 mm from the planned level, then at the planned level with the formation of a spongy autotransl plate-shaped antata, osteoconductive material is used as a bone-substitute material, after plastic bone defect, the obtained autograft is placed on the restored surface.

The disadvantage of this method is that it is not possible to completely fill the bone cavities and cysts with resected bone fragments during endoprosthetics of the knee joint, bone cement penetrates between the bone fragments, there is no restructuring of the plastic material, small bone fragments in the cavity lacking blood supply are resorbed in parallel with the processes of stress remodeling.

There is a method of replacing a bone defect in the tibial condyle with total knee replacement (RF patent No. 2607189.10.01.2017), including resection of the condyles of the femur and tibia, formation of an autograft, installation of test components of the endoprosthesis, plastic bone defect, characterized in that when resection the tibial condyle forms a support area of a trapezoidal shape corresponding to a bone defect, during resection of the femoral condyle form an autograft t trapezoidal shape corresponding to the support pad size plastic bone defect is performed so that the graft lies against the support platform.

The disadvantages of this method are that it does not completely fill the bone cavities and cysts with resected bone fragments, bone cement penetrates between the bone fragments, bone fragments mixed with bone cement, deprived of blood supply, dissolve in parallel with the resorption processes around the components of the endoprosthesis.

A known method of replacing bone defects in total knee replacement (replacement of bone defects in primary knee replacement / NN Kornilov [et al.] // Traumatology and Orthopedics of Russia. 2008. No. 1. P. 76-81), including filling bone deficiency with polymethyl methacrylate, i.e. bone cement, if necessary with reinforcement of 1-3 screws.

However, cement shrinkage during polymerization can reach 2%, and an uneven load distribution on the underlying bone, especially against the background of osteoporosis with eccentrically acting forces, can subsequently lead to a violation of the fixation strength of the components of the endoprosthesis and early instability of the endoprosthesis.

The closest analogue to the claimed invention is a method for replenishing bone defects (RF patent No. 2511455, 04/10/2014), including preparing a bone bed by excising pathologically changed tissues from the future transplantation area and thorough hemostasis, then filling a bone defect with a transplant - allogeneic biomaterial, crushed to coarse or finely dispersed state or a paste prepared by mixing finely divided biomaterial with blood products in the form of platelet s, or fibrin film or other blood products, or with whole blood, characterized in that allogeneic costal cartilage treated with Alloplant biomaterial technology is used as biomaterial, which is placed in acetone cooled to t = 4oC for 24 hours for dehydration, after which dried under vacuum to constant weight, and dispersion is carried out on a rotary impact mill to a particle size of 30 microns to 5 mm, then a fine graft with a particle size of 30-300 microns or large -dispersed with a particle size of 500 microns - 5 mm.

The disadvantages of this method are that allogeneic bone is used as a plastic material, which can cause an immune response in the recipient in the form of an allergic reaction or rejection. When using allografts, the risks of transmission of viral infections remain. Reconstruction of the allograft takes much longer than autologous bone. Bone tissue reconstruction around the endoprosthesis is carried out only due to the recipient's bone bed, the regenerative capabilities of which are significantly reduced against the background of osteoporosis.

These disadvantages are eliminated in the claimed invention.

The objective of the invention is the replenishment of bone deficiency, the creation of a full bed for implantation of the components of the endoprosthesis, ensuring reliable fixation and long-term operation of the endoprosthesis, prevention of the development of early instability of the endoprosthesis in patients with otoporosis.

The problem is solved in that the method of knee arthroplasty in patients with osteoporosis involves preparing a bone bed and then filling a bone defect with a graft, for which bone fragments of the condyles of the femur and tibia are pre-resected, crushed to a particle size from 1.0 mm to 500 microns, a composite is prepared from the obtained autologous bone tissue by mixing with β-tricalcium phosphate in a ratio of 1: 1, the plastic mixture of all cavities, cysts, and bone opilio defects of the femur and tibia, indenting and impressions, then hip replacement is completed in a known manner.

The technical result consists in increasing the strength of fixation of the endoprosthesis and bone, improving the quality of bone tissue, creating a full-fledged bone support for the endoprosthesis, prevention of early instability of the endoprosthesis in patients with osteoporosis.

The technical result is achieved due to the use for filling bone cysts, cavities and defects of a composite osteoplastic material: autologous bone chips obtained by grinding resected fragments of the condyles of the femur and tibia and synthetic β-tricalcium phosphate.

Resected bone fragments of the condyles of the femur and tibia are crushed using a bone mill to crumbs with a particle size of 1.0 mm to 500 microns. Bone crumb is an autologous component of osteoplastic material. The second component is granules of synthetic porous biocompatible and biodegradable ceramics made of β-tricalcium phosphate (β-TCP) and having a well-defined uniform porous structure. After mixing auto-crumbs and β-tricalcium phosphate in a 1: 1 ratio, this composition completely fills the cavities, cysts, bone defects of the bone, sore and depressed. Since β-tricalcium phosphatane is encapsulated, after 12-24 months it is replaced by autologous bone tissue.

Autologous baby does not cause allergic reactions, due to the lack of immunogenicity it has directly osteogenic and osteoinductive properties and has an ideal structure for osteoconduction, it is an ideal plastic material from a biological point of view. Grinding bone fragments to crumbs with a size of 1.0 mm to 500 microns allows you to fill bone cavities and defects of irregular shape as fully as possible.

Synthetic β-tricalcium phosphate is selected among hydroxyapatite-based materials because it is a complete chemical and crystallochemical analogue of the mineral substance of mammalian bone, which determines its unique biological properties: absolute immune compatibility and bioactivity (the ability to stimulate osteogenesis, fuse with bone, and serve as building material for bone synthesis and be part of bone tissue Compared with other hydroxyapatites, β-tricalcium phosphate has increased resorption th, thermal stability - an increase in temperature during the use of bone cement does not accelerate the biodegradation of β-tricalcium phosphate and does not lead to resorption around the prosthesis, which corresponds to one of the main objectives of the claimed invention. Its reconstruction is in accordance with technological parameters. β-tricalcium phosphate is not encapsulated , and completely degrades within 12-24 months, integrating into the structure of the newly formed bone, thereby strengthening it. Restoring bone structure and strength is a leading principle in the surgical treatment of patients with osteoporosis.

A detailed description of the method and examples of its clinical implementation.

The method is applicable in patients of any age with identified osteoarthrosis and osteoporosis.

The method of knee replacement in patients with osteoporosis is implemented as follows. After the formation of the sawdust of the femur and tibia, an examination and assessment of the condition of the bone tissue is performed. Discovered bone cysts are cleansed of adipose tissue. Identified areas of depression and penetration of bone tissue, to fill the frame which requires plastic material.

For osteoplastic material, a composite is prepared as follows. Resected bone fragments of the condyles of the femur and tibia are crushed using a bone mill to a particle size from 1.0 mm to 500 microns. Bone crumb is an autologous component of osteoplastic material. The second component is granules of synthetic porous biocompatible and biodegradable ceramics made of β-tricalcium phosphate (chronOS) and having a well-defined uniform porous structure. After mixing auto-crumbs and β-tricalcium phosphate in a 1: 1 ratio, the cavities, cysts, bone defects of the bone, stitches and impressions are filled with the obtained composite. Then implantation is performed using bone cement on the prepared bed of the femur and tibia.

The performance of the proposed method is confirmed by the following clinical examples.

Clinical example No. 1.

Patient K-va, 77 years old, was operated on for gonarthrosis on 01.03.2017. The patient also had postmenopausal osteoporosis (T criterion -2.4). The patient underwent total arthroplasty of the right knee joint. After distal and proximal filings of the femur and tibia were performed, extensive bone cysts of the anterior surface of the femoral awn and the central part of the tibial plateau were revealed, bone tissue was missed under the influence of instruments. A decision was made on the need for bone grafting of defects. During the fitting of the endoprosthesis and wound repair templates, one of the surgeon's assistants engaged in the preparation of osteoplastic material. Resected bone fragments were crushed using a bone mill to a particle size from 1.0 mm to 500 microns. Autocrash mixed with granules of β-tricalcium phosphate in a ratio of 1: 1. The resulting mixture was tightly tamped with bone cysts, cavities, defects and blotches of the patient’s bone tissue. Performed implantation of the femoral and tibial components of the endoprosthesis. The operation completed in the usual way. After surgery, the patient was prescribed antiresorptive therapy, calcium and vitamin D preparations. On control radiographs after 3.6, 12, 24 months there were no signs of resorption, there was no early instability of the endoprosthesis. With densitometry after 6 months, the T criterion is -2.4, without negative dynamics, after 12 months, the T criterion is -2.3.

Clinical example No. 2.

Patient G-va, 68 years old, was operated on for bilateral gonarthrosis on 05/18/2017. According to densitometry, there were no data on the presence of osteoporosis. The T-criterion of the femoral neck on the side of the planned operation is 1.2. However, during the operation, the patient revealed a significant decrease in the strength and quality of bone tissue, which does not correspond to densitometry. Extensive bone cysts of the anterior and distal surfaces of the femur and the central and posterior parts of the tibial plateau were revealed, bone tissue was missed under the influence of instruments. A decision was made on the need for bone grafting of defects. During the fitting of the endoprosthesis and wound repair templates, one of the surgeon's assistants engaged in the preparation of osteoplastic material. Resected bone fragments were crushed using a bone mill to a particle size from 1.0 mm to 500 microns. Autocrash mixed with granules of β-tricalcium phosphate in a ratio of 1: 1. The resulting mixture was tightly tamped with bone cysts, cavities and defects. Performed implantation of the femoral and tibial components of the endoprosthesis. The operation completed in the usual way. After the patient was prescribed antiresorptive therapy, calcium and vitamin D preparations. On control radiographs after 3, 6, 12, 24 months there were no signs of resorption, there was no early instability of the endoprosthesis. With densitometry after 6 months, the T criterion is 1.3, after 12 months the T criterion is 1.2.

Medical and social effectiveness of the method is:

- improving the results of knee replacement in patients with osteoporosis;

- in reducing the risks of instability of endoprostheses;

- reducing the cost of treating complications;

- in improving the quality of life of patients.

Thus, the method of knee arthroplasty in patients with osteoporosis can make up for bone deficiency, create a complete bed for implantation of endoprosthesis components, ensure reliable fixation of the endoprosthesis, reduce the number of complications, reduce treatment costs and improve the quality of life of patients.

The inventive method of knee replacement in patients with osteoporosis has been tested on extensive clinical material and can be recommended for use in clinical practice in trauma and orthopedic hospitals.

Claims (1)

A method for knee replacement in patients with osteoporosis, including preparing a bone bed and then filling a bone defect with a graft, characterized in that the bone fragments of the condyles of the femur and tibia are resected, crushed to a particle size of 1.0 mm to 500 microns, and a composite is prepared from the obtained autologous bone tissue by mixing with β-tricalcium phosphate in a ratio of 1: 1, the resulting mixture plasticizes all cavities, cysts, bone defects of the femoral sawdust th and tibia, indenting and impressions, and then the implantation of the prosthesis with bone cement on the prepared bed of the femur and tibia.