Revision arthroplasty of the femoral component of the endoprosthesis. Revision knee arthroplasty

The task of the surgeon in primary hip or knee arthroplasty is to return the patient to a normal life as soon as possible. Restoring the anatomical shape with the help of artificial components and physiological mobility joint, the surgeon tries to ensure a long and reliable service of the installed structure. It is very important to comply with all the requirements of operating technique and sterility in order to avoid the need for a second revision operation in the future. Re-replacement of a previously installed endoprosthesis is a more complex, lengthy and statistically less successful procedure, which has its own risks and complication rates. Unfortunately, with the growing number of operations for the primary installation of endoprostheses in the world, the number of complications requiring revisions is also growing. During repeated operations, surgeons often face the problem of a postoperative defect (lack) of bone mass, primarily in the area of ​​the acetabulum of the pelvis and the articular end femur.

The main indication for revision surgery is the functional failure of the installed prosthesis. As a result of inadequate fixation of the installed components of the prosthesis to the bone structures, the joint becomes “loose”, which does not allow it to perform the entire range of movements. As a result of pathological mobility of the internal elements of the joint, the process of chronic destruction of its bone part and the formation of fibrous tissue around the endoprosthesis starts.

The causes of instability and loosening of the endoprosthesis (loosening), with the exception of technical errors during the operation, can be:
a) aseptic or non-microbial, sterile process (aseptic loosening) as a result of an inflammatory reaction of periarticular tissues to microdust (debris) resulting from mechanical friction of parts of the prosthesis during movement;
b) septic or microbial process as a result of chronic infection in the joint area (septic loosening).

Aseptic loosening of the endoprosthesis

High-strength artificial endoprosthesis materials, despite their durability, are not capable of self-healing, similar to tissue regeneration of living organisms. Over time, the rubbing contact surfaces of the components are "worked out", forming microdispersed dust. Microdust penetrates into the tissues surrounding the joint and causes reactive inflammation, destruction and melting of the bone elements of the joint, followed by their replacement with fibrous tissue.

The rate of development of the process according to the type of aseptic loosening directly depends on the level of mechanical load on the joint, the degree of physical activity of the person and the material of the friction pair in the installed endoprosthesis. A pair of friction is two contact parts of the joint that provide the process of its movement. The material of the friction pair, least of all resistant to mechanical stress, is polyethylene, which has a high abrasion coefficient. However, modern technology for the manufacture of polyethylene with reinforced fiber bonds (highly crosslink polyethilen) has made it possible to significantly improve its strength characteristics. Ceramic-metal has the highest wear resistance in a friction pair.

Septic loosening of the endoprosthesis

Infection of the surgical wound and prosthesis is a serious postoperative complication. Therefore, the requirements for the sterility regime during arthroplasty operations are the highest in orthopedic surgery. The principles of prevention of purulent complications must be strictly observed by the operating personnel. Despite all the precautions taken, according to world statistics, infection accounts for 1% to 5% of endoprosthetic complications. Infectious complications are divided into acute and chronic.

Acute infection or suppuration of the surgical wound

Acute infection usually develops in the superficial soft tissues surgical wound without penetration into the deeper layers and without involvement of the installed endoprosthesis in the infectious process. Its development becomes possible with weakened immunity of the patient and non-compliance with measures of infectious prophylaxis, violation of sterility and microbial contamination of the wound surface. From the wound discharge, as a rule, is sown Staphylococcus aureus(staphylococcus aureus). After determining the sensitivity of microbes to antibiotics, an intravenous course of antibiotic therapy is prescribed. The duration of treatment takes from several days to a month.

If antibiotic therapy is ineffective, surgical cleansing of the wound is performed, necrotic tissues are removed, while the endoprosthesis remains in place. At the same time, a new antibiotic or a combination of them is selected. If the treatment tactics is chosen correctly, the infection is completely eliminated and the endoprosthesis is preserved. When treatment fails acute infection may become chronic.

chronic infection

The appearance in the area of ​​the performed operation of signs of a local chronic infection is the most severe infectious complication that occurs after arthroplasty. It can develop as an independent primary form of the disease or as a result of ineffective treatment of the acute phase of the infection. The causative agent of the primary form of chronic infection more often than others becomes epidermal staphylococcus aureus (staphylococcus epidermidis). Colonies of staphylococci grow on the metal components of the endoprosthesis and, with the help of glycocalyx molecules, protect themselves from being destroyed by immune system cells and antibiotics. As microbes with a low degree of pathogenicity, staphylococci, getting into the surgical wound, do not cause a pronounced immune response and the classic picture of suppuration. Therefore, in the early postoperative period, a chronic infection does not give itself away and is not diagnosed. Subsequently, it is manifested by the presence of constant pain in the joint area. Relatively quickly, from one to two years after surgery, the infection destroys the bone around the endoprosthesis. At this time, the symptoms of instability of its components progress. The diagnosis is established by examining the patient, evaluating his complaints, x-rays and laboratory tests. Identified chronic infection is a direct indication for the revision of the endoprosthesis. To reliably get rid of a chronic infection, the infected endoprosthesis is removed. For this, there are two types of revision operations - one-stage and two-stage replacement of the endoprosthesis.

One stage revision

In this type of surgery, the infected endoprosthesis is removed, the surrounding necrotic tissue is removed, and the wound is surgically cleaned. A new, revision endoprosthesis is installed in place of the old one. Taking into account microbial sensitivity, a lengthy, up to 6 weeks, course of antibiotic treatment is carried out. The use of such tactics gives successful results with the complete elimination of chronic infection in 70% of cases.

Two-stage revision

At the first stage, the infected endoprosthesis is removed, and after the wound is cleaned, a temporary articular spacer is installed in its place. The latter is similar to the primary endoprosthesis, but is encased in acrylic cement with a high concentration of antibiotic. Cement allows filling all bone defects and creates a high local concentration of the antibiotic. This allows to reduce the course dose of postoperative intravenous antibiotic therapy. The use of an articular spacer helps to restore the patient's ability to walk with full load on the joint. After 3-6 months or more, in the absence of clinical and laboratory signs of infection, the second stage of the operation is performed - the removal of the spacer and its replacement with a revision endoprosthesis. When applying a two-stage revision tactics, the success rate rises to 90% of cases.

aim revision arthroplasty is the creation of a strong joint structure, including good fixation of the stem, a stable joint and restoration of the bone base of the femur. However, there are many factors that make it difficult to achieve the goals. Among them, the most important are the following: large bone defect, joint instability, infection, fracture of the femur (as a result of massive osteolysis), lack of fusion of the greater trochanter. When replacing a femoral component, the surgeon may face the problem of removing the implant and cement residue, fracture of the femur, perforation of the cortical wall, lack of strong fixation of the implant, etc.

Therefore, during preoperative planning, it is necessary to answer the following key questions: what is the optimal approach to the hip joint; how best to remove the implant with minimal trauma to the bone tissue; what type of reconstruction and type of stem is best to use, how to achieve a strong fixation of the component; how to replace a bone defect.

Preoperative planning.

In preoperative planning, it is necessary to carefully analyze the history of the disease and answer the above questions. It is important to know the details of the previous operation, the description of operational and postoperative complications, as well as to clarify the complaints that made the patient seek advice.

The importance of a detailed history taking cannot be overestimated. For example, if a patient after primary arthroplasty had pain all the time, or pain appeared after a short time, an increase in body temperature was observed, then we can assume the presence of a latent infection. With such a course of the disease, the efforts of surgeons should be aimed at finding the source of inflammation. This can be helped by blood tests (presence of leukocytosis, ESR, C-reactive protein, the study of the level of pro-inflammatory cytokines, in particular, interleukins 1α, 1β, factor 8, tumor necrosis factor), aspiration of contents from the cavity hip joint and microbiological research.

It is desirable to determine the mechanism of development of instability femoral component. Even before the operation, the surgeon must know the type and size of the previously installed prosthesis.

Clinically, the instability of the endoprosthesis stem is manifested by pain in the thigh area, which increases with physical activity and goes away after rest. During examination, pain can be induced by creating a forced axial load on a limb or by performing rotational movements in the position of extension or flexion in the hip joint.

The next stage of the examination of the patient is the study of radiographs of the pelvis, thigh (with the capture of the entire femoral component) in the direct and lateral projections and the acetabulum in the lateral projection. Changes on radiographs should be evaluated in dynamics in comparison with the primary ones, while it is important to pay attention to subsidence and other changes in the position of the implant, the extent and severity of osteolysis, the quality of bone tissue, the presence of bone defects, the location of the cement mantle and cement plug, the state of the cortical walls. There may be other pathological changes such as periprosthetic fracture, heterotopic ossificates, non-union of the greater trochanter at the site of osteotomy.

It is advisable to carry out preoperative planning together with the entire surgical team. Although not always possible, one should strive to create a complete picture of the affected area of ​​the bone, having a plan for accessing the hip and femur to remove the implant and bone cement while sparing the bone and surrounding muscles. Along with the main one, it is always necessary to have several alternative options for the operation.

All patients with pedicle instability have bone tissue deficiency of varying severity. The results of revision arthroplasty often depend on the size of the bone lesion and the ability of the surgeon to restore the bone base of the femur. The choice of operation method also depends on the degree of bone tissue destruction. Therefore, an important element in the development of a treatment strategy is the classification of its defects, which involves not only a description of the extent and localization of the osteolysis zone, but also a certain treatment strategy. In our practice, we use the Mallory classification, which distinguishes four categories of femoral defects with instability of the femoral component.

• Type I - intact spongy bone tissue of the proximal femur without wall thinning and bone deficiency, intact cortical tube.
• Type II - deficiency of spongy bone tissue of the proximal femur with a preserved cortical tube. Small defects in the metaphysis and thinning of the cortical wall of the femoral shaft are possible. However, the metaphyseal part is able to provide good fixation and ingrowth of bone tissue into the porous coating of the endoprosthesis stem.
• Type III - deficiency of spongy bone tissue of the proximal femur and violation of the integrity of the cortical tube. Stable fixation of the endoprosthesis is impossible due to defects in the bone tissue of the metaphysis and perforation of the diaphyseal part of the femur. W.G. Paprosky subdivides this type of femoral defect into two subgroups depending on the state of the cortical bone tissue in the isthmus: subtype A - at least 4 cm of the diaphyseal tube is preserved, and fixation of the prosthesis stem is possible along this length, subtype B - the length of the preserved bone tissue in the isthmus less than 4 cm, it is possible to fix the implant only in the distal parts of the femur.
• Type IV - the absence of spongy and cortical bone tissue of the proximal femur with the formation of a segmental defect.

Access to the hip joint.

The choice of access is determined by the experience and degree of convenience for the operating surgeon. In our practice, for revision arthroplasty, we used a direct external approach (even if the first operation used a posterior approach), similar to that described earlier in Chapter 6. However, in some cases with extensive scarring, possible difficulties in removing bone cement, we use an approach with extended osteotomy proximal femur. For all its apparent trauma, it ensures maximum preservation of the remaining soft tissues and good review operating field.

Removal of the implant.

An important stage of surgical intervention is the removal of the endoprosthesis. When cementing the stem, it is necessary to determine the degree of implant mobility, the dimensions of the cement mantle, and the strength of the connection between the latter and the bone. According to the X-ray examination, it is possible to determine the shape of the stem (straight or curved), the localization of loosening (on the bone-cement or cement-implant interface), and the depth of the cement plug. With cementless stem fixation, the main issue is the degree of osseointegration with the implant surface, because in the presence of a strong fixation of the stem, a fundamentally different surgical technique is required to remove it (in contrast to the option when the implant is unstable).

When removing the endoprosthesis, it is necessary to avoid additional damage to the bone tissue in every possible way. The operation begins with the careful removal of soft tissues, bone deposits and cement around the proximal part of the stem so that it does not jam when knocked out. After successful removal of the stem, it is necessary to free the bone canal from the remnants of the cement mantle and the distal cement plug. For this, there are various special tools: curved and straight chisels, wire cutters, high-speed burs, ultrasonic nozzles, etc. When working with these instruments, special care must be taken not to perforate the femoral wall. To control the position of the instruments and better visualize the completeness of cement removal, it is sometimes recommended to make a burr hole in the cortical femoral wall 2–3 cm below the plug. This allows the surgeon to control the position of the drill when perforating the cement plug (for its subsequent removal with a corkscrew), as well as to be sure that the bone canal is completely free of cement residues and bone chips. If the bone cement is very firmly fixed, or the cement plug is located far distally, a surgical technique similar to that used to remove a porous-coated uncemented stem is used. The essence of the operation is a longitudinal osteotomy of the proximal femur, as a rule, to the middle of the endoprosthesis stem or the distal edge of the porous covering of the femoral component, i.e. about 10 - 12 cm from the tip of the greater trochanter. The femur must remain intact for at least 4-6 cm below the osteotomy for subsequent fixation of the revision stem.

As an example revision arthroplasty with a longitudinal osteotomy of the femur, we present a clinical observation.

Patient L., aged 40, first came to the clinic in 1992. During the examination, the diagnosis was made: bilateral coxarthrosis due to aseptic necrosis femoral heads. In the same year, primary arthroplasty of the left hip joint was performed with implantation of the ARETE endoprosthesis, in 1993, therapeutic intertrochanteric osteotomy was performed on the right. Progressive pain in the left hip joint reappeared in 1995. X-ray examination revealed a fracture of the endoprosthesis stem, osteolysis of the proximal femur. On February 5, 1998, revision arthroplasty of the left hip joint was performed. Extended trochanteric osteotomy of the proximal femur was performed from the posterior approach along the muscle attachment line, followed by transverse transection of the femur and osteotomy of the anterior cortical wall. The revision of the hip joint revealed that the acetabular component was stable, however, between the cup and the bottom of the acetabulum there were a large amount of polyethylene abrasion products and granulation tissue. Both fragments of the endoprosthesis stem were removed, the entire proximal section was carefully treated with a bone spoon, and the granulation tissue was excised. The acetabular component was removed, after processing the cavity with cutters, a cementless fixation cup with a diameter of 66 mm was installed and additionally fixed with a screw. The distal femur was treated with drills (up to 13 mm), after which a revision leg of the endoprosthesis with a diameter of 13.5 mm with a full porous coating was inserted. The length of the stem (200 mm) was chosen taking into account that at least 6-8 cm of the implant was located in the intact area of ​​the femur. The space between the endoprosthesis and the endosteal surface of the proximal femur was densely filled with bone chips. The osteotomy line and the thinned walls of the proximal femur were reinforced with a cortical fibula autograft. When examined after 4 years, the patient had no complaints, walks with full load on the operated leg.

Radiographs of the left hip joint of patient L. with a fracture of the endoprosthesis leg, osteolysis of the proximal femur: a — before surgery; b — a long revision leg of the endoprosthesis was installed, bone grafting of defects with cancellous bone tissue, an osteotomy line and thinned walls of the proximal femur were strengthened with cortical allografts; c — 4 years after the operation: stable fixation of the endoprosthesis, restructuring of bone grafts.

There are a large number of operations aimed at achieving stable fixation of the endoprosthesis stem in revision arthroplasty. The most widely used methods are cemented and cementless implant fixation using various types of bone grafting (cortical allografts, cancellous bone tissue impaction, transplantation of the entire proximal femur).

Revision arthroplasty with cemented stem.

The use of cemented legs in revision arthroplasty has both positive and negative sides. The main advantage is to achieve almost immediate implant stability and ensure early patient mobilization. However, one must be aware that often the endosteal surface of the femur is so sclerosed and smooth that it is impossible to achieve the same strong fixation of the cement as in primary arthroplasty. Studies by Y. Dohmae et al showed that in revision cement arthroplasty, the adhesion force between the endoprosthesis stem and bone tissue decreases by 20.6%.

In addition, there are technical problems that prevent good bone cement pressurization when using long stems, there is a risk of losing even more bone tissue if the newly implanted revision stem becomes unstable, and the need for revision arthroplasty. The results of the use of cemented legs are extremely controversial. The frequency of reoperations ranges from 3 to 38%, and if we take into account radiological signs, then the frequency of implant instability will increase to 53%. Modern cementation technique (careful preparation of the canal, use of distal plugs and pressurization) has improved the results of operations, however, even in this case, the number of repeated surgical interventions remains quite high and amounts to approximately 10% with an average follow-up of 9 years. Sometimes, especially in elderly patients, and in cases of removal of legs to facilitate revision of the acetabular component, it is possible to install a new implant on cement without removing the old cement mantle. J.R. Lieberman et al. reported 19 patients with no signs of osteolysis with follow-up periods of at least 59 months.

As an example of the use of a cemented stem in revision arthroplasty We present a clinical observation.

Patient Sh., 65 years old, was operated on for the first time in 1992, when Gerchev's endoprosthesis was implanted for left-sided coxarthrosis. The pain recurred in 1996, at the same time a fracture of the endoprosthesis stem was detected. In November 1996, an operation was performed in one of the city hospitals to strengthen the stem of the endoprosthesis using bone autografts. In the postoperative period, suppuration of the wound developed, and therefore the prosthesis was removed in the clinic. A year after the relief of the inflammatory process, revision arthroplasty was performed (12/23/98). Access with cutting off the greater trochanter exposed the left hip joint, the acetabulum was processed with cutters up to 55 mm, a cementless fixation cup 58 mm was installed and additionally strengthened with two screws. The medullary canal was opened and treated with a conical reamer. At the same time, it was revealed that the greater trochanter was fused in the position of abduction and rotation, the femoral canal was sharply deformed, and there was a wedge-shaped bone defect on the anterior wall of the femur for 8 cm.

The integrity of the cortical tube was restored with cortical allografts fixed with cerclage sutures. The femoral canal was processed with rasps, a bone plug was inserted, after which a revision leg with cement fixation was installed. The large trochanter is brought down and fixed with a screw. When examined after 3 years, the patient has no complaints, walks with a full load on the leg, uses a cane when moving over long distances. The choice of a cement stem was due to a severe deformation of the bone canal and the need for an operation with minimal blood loss as soon as possible due to kidney disease.

Radiographs of the left hip joint of patient Sh., 65 years old, with a fracture of the endoprosthesis leg, osteolysis of the proximal femur: a — before surgery; b — area of ​​the hip joint after removal of the endoprosthesis: severe hip deformity, the greater trochanter has fused with abduction and rotation; c — a hybrid endoprosthesis with osteoplastic restoration of the continuity of the cortical wall was installed.

Revision arthroplasty with cementless stem

In connection with the problems listed above that arise when using cemented legs, it is preferable to use components designed for bone tissue ingrowth. Although the follow-up period for patients is not as long as after cement revision arthroplasty, the results of operations are better (compared to the same periods), and this advantage is predicted for more long time. When choosing implants for cementless fixation, it must be remembered that they are divided into stems designed for proximal and distal fixation. The unsatisfactory results of the first operations were due to the fact that for defects in the proximal femur, stems were used that could provide osseointegration only in their proximal part. After the analysis of complications, so-called fully covered revision legs were used, designed for fixation throughout their length, and, above all, in the diaphyseal part.

The long-term results of the use of modern revision legs showed that the frequency of reoperations ranges from 1 to 5% with an average follow-up of 8 years. In comparison, the revision rate for proximal fixation implants is 42%, which again emphasizes the importance of distal fixation.

In recent years in clinical practice modular legs are being actively introduced, involving separate fixation of the diaphyseal and metaphyseal parts. The advantage of using such implants lies in the possibility of individual separate selection and installation of the diaphyseal and proximal parts, each of which can have several types of designs and sizes, which makes it easy to adjust the length of the stem, neck, fixation stability and anteversion. The porous coating of the prosthesis ensures good bone tissue integration. The free rotation of the proximal part of the stem ensures the selection of the optimal position of the neck of the prosthesis and thus significantly increases stability. The disadvantages of implants of this type include the possibility of mobility and the formation of titanium microparticles at the junction of the distal and proximal parts of the endoprosthesis. The S-ROM modular endoprostheses (DePuy, Warsaw, Indiana), which have been used since 1984, have the longest period of clinical observation.

As observations have shown, the frequency of good results ranges from 87 to 96% with follow-up periods of up to 4-6 years. Such systems of revision endoprostheses are becoming more and more popular. There are several of their developments performed by various companies, including a modular endoprosthesis of the ZMR system from Zimmer.

Patient B., aged 83, with instability of the right hip joint and fracture of the leg of the endoprosthesis, dystrophic changes in the acetabulum: a — radiograph before surgery; b — after revision arthroplasty using extended femoral osteotomy and installation of a modular ZMR endoprosthesis (Zimmer).

As an illustration, we present a clinical example of the use of a cementless revision stem.

Patient B., 69 years old, as a result of a fall in 1994, received a fracture of the neck of the right femur. He was treated conservatively, due to the development of a false joint of the femoral neck in 1995, an operation was performed: primary hip arthroplasty with the installation of an ARETE endoprosthesis. Pain in the hip joint appeared in 1997, and as a result of a fall on the leg against the background of osteolysis of the femur, a pathological fracture of the femur was detected. Taking into account the presence of a fracture, changes in the bone tissue over a large extent, for revision arthroplasty (22.04.98) a fully covered stem Solution 254 mm with a bend in the sagittal plane (stem diameter 16.5 mm) was used. In addition, thinned cortical walls were reinforced with cortical allografts. The choice of such a long stem was due to the fact that the osteolysis zone was located throughout the entire stem of the ARETE endoprosthesis (and its length is 180 mm), and primary distal fixation could be provided only by additional lengthening of the implant.

Radiographs of the right hip joint of patient B., 69 years old: a — instability of the endoprosthesis of the right hip joint; b, c, d — the acetabular and femoral components of cementless fixation were installed, the proximal femur was reinforced with cortical allografts; e, f — result after 5 years.

When choosing long revision stems (200 mm or more), one must be aware of the existence of a real risk of perforation of the cortical wall.

Radiographs of the right hip joint of patient G., 67 years old: a, b — perforation of the anterior wall of the femur during the installation of the revision stem (length 200 mm); (c) the exit site of the pedicle was reinforced with a cortical allo-bone graft.

Revision cement arthroplasty of the femoral component using bone tissue impaction

This revision arthroplasty technique was developed in the UK by G.A Gie in 1985 as an alternative to cemented arthroplasty (similar to acetabular bone grafting). Two years later, he began to perform the same operation, but with the use of bone cement. Initially, the Exeter stem (double-tapered, polished, without collar) was used as implants, and the CPT stem, which has a similar design, is now more commonly used. The purpose of the operation is to restore the bone base of the femur (due to dense filling of the defects of the femur with crushed spongy allograft) and to firmly fix the endoprosthesis stem using bone cement. The advantages of surgical intervention include the formation of a new bone marrow canal with dense filling of all cavities with bone tissue. In some cases, the cortical walls of the femur are so thin that they require preliminary strengthening with cortical allo-bone grafts. The operation technique is as follows.

After removal of the unstable stem of the endoprosthesis, residual bone cement and granulation tissue a plug and a guide rod are installed in the femoral canal, on which a smooth template of the endoprosthesis is put on. This template completely repeats the shape of the stem, but its dimensions are 2 mm larger than the dimensions of a true implant (to create a cement mantle). After the template is correctly oriented, bone chips are placed around it and tightly hammered. As a graft, it is preferable to use the allosseous tissue of the femoral heads. If there is a perforation of the cortical wall, cortical allografts are first placed around the femur and fixed with cerclage sutures in such a way as to strengthen the bone and close the hole. After the impaction of the bone tissue is completed, the template is removed, bone cement is retrogradely injected using a gun, and the original endoprosthesis stem is installed. The technically difficult moment of the operation is the creation of a dense impaction of the allo-osseous tissue in the distal part of the pedicle and the observance of the correct spatial orientation of the implant.

Theoretically, if successful, the femur is repaired with remodeling of the cortical walls. According to various authors, good results of the operation were achieved in 78-91% of cases, however, one must keep in mind the relatively short periods of long-term follow-up (13-32 months). With all the relative simplicity and attractiveness of this surgical technique, it is necessary to take into account a large number of complications that occur in the long-term period after surgery. The most typical and frequent is the subsidence of the stem, which occurs mainly at the border of the bone allograft and cementum. The frequency of downward displacement of the stem ranges from 23 to 79%, large subsidence (more than 10 mm) is observed in 10 - 15%. The degree of subsidence depends on many factors. It occurs in the first 2 years after surgery, a small displacement (5-8 mm), as a rule, is not accompanied by pain, while a displacement of more than 10 mm leads to the development of pain in the thigh. In addition, subsidence of the stem at the cement-implant interface is observed (in 10% of cases). The frequency of femoral fractures ranges from 5 to 24%, hip dislocations - from 3 to 6%.

Considering a fairly large number possible complications, little experience in performing these operations and short follow-up periods, indications for osteoplastic reconstruction of the femur using a cemented stem are type II femoral defects in young patients or a large hip lesion, when it is difficult to perform another operation.

R.M. Tikhilov, V.M. Shapovalov
RNIITO them. R.R. Vredena, St. Petersburg

Modern joint endoprostheses are reliable and durable and in most cases provide an opportunity for an active life without pain, serious restrictions and the need for repeated operations.

However, sometimes there is still a need to replace an already installed endoprosthesis.

This operation is called "revision arthroplasty".

Today in the world there are millions of people with artificial joints.

Many have lived with them for many years and decades. Statistics show that the probability of the need to replace the endoprosthesis for each of them increases with each passing year.

Therefore, in some countries, the share of revision operations is 8-10% of all arthroplasty operations.

In Russia, this figure is still lower, but the number of revisions is increasing every year.

The main thing to understand is that the need for revision joint arthroplasty is not a disaster!

After the operation, the normal function of the joint is restored and the new endoprosthesis continues to perform its tasks successfully.

The specificity of performing revision operations implies increased requirements for the equipment of the operating room and the clinic as a whole, for accessibility various materials- endoprostheses, special structures for osteosynthesis and replacement of bone defects, etc.

2. When are revision operations indicated?

There are many conditions that may require revision arthroplasty. Below is an overview of the indications for revision surgery.

1. Dislocations in an artificial joint

Most often it concerns endoprostheses of the hip and shoulder joints. Regularly recurring dislocations make normal activity impossible and reduce the quality of life.

The reasons

Disturbed position of the endoprosthesis components or, for example, the state of periarticular tissues and formations - muscles, ligaments, tendons. Also, the reason may be a clear neglect of the recommendations on the motor regimen or the inability to control movements in the operated joint (for example, due to a stroke).

Solutions

To eliminate the cause of a systematically occurring dislocation, as a rule, an operation is indicated. In its course, the disturbed position of the components of the endoprosthesis can be normalized, some of its elements can be replaced, and a special (anti-dislocation) endoprosthesis can be installed.

How to avoid?

• Choose a surgeon with sufficient experience.
• Ask before the operation how high the risk of dislocations is in your case and what actions the surgeon intends to take to prevent dislocations?
• Start performing a set of exercise therapy exercises to strengthen muscles in advance (you can download guidelines for and joint).

2. Wear of friction unit materials in an artificial joint

The reasons

Any device in which friction occurs, especially under load, is subject to wear. When designing joint endoprostheses in the friction unit, very durable materials are used, but wear still occurs gradually, especially in the case of a metal/polyethylene friction pair.

You can read more about the wear resistance of endoprostheses.

Solutions

A revision operation is shown to replace worn components. However, the operation is almost never limited to this - due to the reaction of tissues to wear products (particles of polyethylene, metal), it may be necessary to replace the entire endoprosthesis, along with the replacement of bone defects formed.

How to avoid?

• Discuss with the surgeon in advance the durability of the endoprosthesis to be installed, the materials of the friction unit. The most durable endoprosthesis should be chosen (if possible).
• Trust the installation of the endoprosthesis to an experienced surgeon. Inaccurate installation increases the rate of wear.
• Do not subject the endoprosthesis to excessive loads, follow the recommendations of the operating surgeon.

3. Instability of the endoprosthesis (loosening)

The reasons

Here we are talking about aseptic instability, that is, when loosening is not associated with the presence of infection in the area of ​​the endoprosthesis. Sometimes the endoprosthesis loses its strong connection with the bone, and, as a rule, the likelihood of this phenomenon increases over the years. Most often, aseptic instability occurs as a result of exposure to wear products of the friction unit.

Solutions

Developed instability is an indication for revision arthroplasty in order to install another, most often a special revision one. Such endoprostheses provide the possibility of reconstructing lost tissues and, as a rule, have longer stems to ensure strong fixation in the preserved parts of the bone.

How to avoid?

The choice of a high-quality endoprosthesis with a durable friction pair will minimize the risk of aseptic instability. Do not forget also the recommendations for point "2" (see above).

4. Infection of the endoprosthesis (deep periprosthetic infection)

The reasons

Microorganisms can enter the endoprosthesis in various ways, for example, with the blood or lymph flow (hematogenous or lymphogenous route of infection) or, for example, as a result of medical manipulations- injections, etc.

The path of direct infection of the endoprosthesis during surgery is a rarity, since the operations are performed under the strictest aseptic conditions (its rules for orthopedic operations are the most stringent).

Complexities of treatment

If an infection develops in the area of ​​the endoprosthesis (as well as in the area of ​​any artificial device in the body - a heart valve, a vessel prosthesis, a pacemaker), it is most often impossible to defeat it by conventional methods - by prescribing antibiotics.

The fact is that, having settled on artificial organs, the infection becomes inaccessible to the action of antibiotics, other antimicrobials and, most importantly, the immune system.

Solutions

With the development of infection, surgical treatment is indicated. For some favorable conditions, when early development infection, good effect can give the operation of debridement of the postoperative wound. However, in most cases, more extensive operations are indicated.

Revision operations for infection are among the most complex and are most often performed in several stages. At the first stage, the infected endoprosthesis is removed, tissues are thoroughly cleaned from infection, and a special device, a spacer, is installed that temporarily replaces the endoprosthesis and serves as a source of antibiotics that are part of it to destroy the infection.

In parallel, active long-term antibiotic therapy is carried out. After healing and in the absence of signs of recurrence of the infection, repeated arthroplasty can be performed. The shortest possible time between operations is 1.5 months.

How to avoid?

An important point of prevention is the rehabilitation of all inflammatory foci in the body before arthroplasty. This should be taken very seriously. One of the requirements is always the sanitation of the oral cavity at the dentist's appointment (a frequent occurrence is chronic foci of infection in the teeth).

It is also mandatory to conduct a course of antibacterial drug prevention, for this purpose, a short course of antibiotics is prescribed during and after the operation.

The technique and duration of the operation also affects the frequency of development of infectious complications, therefore, for its implementation, you should choose a clinic in which joint replacement operations are performed regularly. The experience and competence of the surgical team also matters.

5. Fracture of the bone at the site of fixation of the endoprosthesis (periprosthetic fracture)

The reasons

Unfortunately, no one is immune from injury, even people with artificial joints. Sometimes, as a result of a fracture, the endoprosthesis becomes unstable and needs to be replaced.

Solutions

Fractures can be of various types. In some cases, it is permissible to perform osteosynthesis and leave the already installed endoprosthesis. In others, it is necessary to replace the endoprosthesis with a revision one with simultaneous restoration of bone integrity.

For reliable fixation of the revision endoprosthesis in case of a complex fracture, bone reconstruction is performed during the operation. For this purpose, it is necessary to use rather complex devices (special plates, etc.), the cost of some of them is close to the cost of an endoprosthesis.

How to avoid?

There are no specific means of preventing periprosthetic fractures. However, careful behavior in the presence of an artificial joint should always be preferred to activities with a high risk of injury.

REMEMBER: Treatment of a periprosthetic fracture can be significantly longer, more difficult, and more expensive than that of a normal bone fracture.

6. Incorrect initial installation of the endoprosthesis

Manifestations are diverse (dislocations, pain, impossibility of some movements, inequality in the length of the legs) and strongly depend on which joint is prosthetized.

Sometimes the incorrect position of the endoprosthesis components does not manifest itself in any way and only over time can lead to too early wear of the friction unit. In other cases, an indicator of incorrect installation of the endoprosthesis may be an incident that occurred without visible reasons periprosthetic fracture.

The reasons

Of course, inaccurate installation of the endoprosthesis is the result of a surgeon's mistake, and we have to admit that such cases, albeit very rarely, are observed even among highly qualified and very experienced surgeons. The probability of error can be increased, for example, by the patient being very overweight.

Solutions

Reinstalling inaccurately located components is not always possible; after removing existing ones, you have to install new ones. Naturally, this affects the cost of treatment.

Removal of stable endoprosthesis components can be associated with significant technical difficulties. Therefore, such operations are often quite lengthy.

How to avoid?

It is known that the more experience the operating team of surgeons has, the less the likelihood of inaccurate placement of the endoprosthesis. Equipping the clinic with equipment and the presence of competent rehabilitation specialists in it is also important.

7. Breakage or destruction of endoprosthesis elements

The reasons

Breakage may be due to poor quality of the endoprosthesis, but sometimes we observe breakage of even very high quality endoprostheses. This can happen after very many years of normal operation (so-called fatigue fractures). In addition, the failure of the endoprosthesis may be the result of not quite correct installation. Due to the high quality of most modern endoprostheses, breakdowns are very rare.

Breakage of ceramic heads of hip endoprostheses is occasionally observed as a result of a serious injury.

Solutions

If the endoprosthesis is broken, it must be replaced. At the same time, operating surgeons sometimes have to deal with the extremely difficult removal of broken fragments if they remain deep in the bone. Often, for the complete removal of all fragments, it is necessary to do an osteotomy - additionally dissect the bone with its subsequent restoration - osteosynthesis.

How to avoid?

The most important thing is not to save on the quality and correct selection of the endoprosthesis!

8. Allergic reactions to the endoprosthesis

Despite the fact that all endoprostheses are made from materials with good biocompatibility, ions of such metals as Nickel, Cobalt, Chromium, Molybdenum, Tungsten, Manganese, Vanadium, Aluminum and, as a rare exception, Titanium, can become allergens.

Materials such as ceramics or ultra-high molecular weight polyethylene, widely used in endoprosthetics, are not allergenic.

Solution path

In the case of a developed allergy to metal, the endoprosthesis is replaced with a special one, made of completely non-allergenic materials or having a special surface structure that prevents free access of metal ions to the tissue fluid.

How to avoid?

If you are experiencing contact dermatitis when wearing metal objects (buckles, buttons, jewelry, etc.) or intolerance to metal dentures, be sure to warn the operating orthopedic surgeon about this!

You are shown the use of obviously non-allergenic endoprostheses.

3. Features of the operation

The goal of any revision arthroplasty is similar to the goal of the primary surgery. That is: relieve pain, restore normal function of the joint, provide support (in the case of a joint lower limb) etc.

However, the surgeon is faced with much more complex tasks:

• perform the removal of the existing endoprosthesis in the most accurate and least traumatic way;
• ensure high-quality fixation of the endoprosthesis under conditions, as a rule. bone deficiency;
• minimize the likelihood of dislocation in the joint (during revision operations, the frequency of dislocations is much higher);
• sanitize tissues from wear products of the friction unit or infection;
• choose the most suitable as a revision endoprosthesis;
• THE MAIN THING is to be ready for any change in the course of the operation and have the best solutions ready!

This is why revision surgeries are considered to be significantly more complex and require the surgeon and all staff to heightened attention and dedication!

Characteristic difficulties

During revision surgery, surgeons face the following difficulties:

• removal of cement from the bone (with cement fixation of the endoprosthesis);
• removal of stable, well-anchored implants with minimal removal of healthy bone;
• prevention of intraoperative bone fractures;
• assessment of the compatibility of endoprosthesis components from different manufacturers and models, if partial replacement is necessary.

Performing a revision surgery from the point of view of an orthopedic surgeon is similar to a game of chess, during which it is necessary to anticipate the possible development of the situation several moves ahead and, most importantly, to have turnkey solutions for most possible problems.

That is why revision surgeries are performed by the most experienced professionals.

Postoperative regime

Features of the postoperative regime very much depend on which joint it was performed on, what caused the revision, what endoprosthesis was installed and what method of its fixation. The recovery mode, therefore, is compiled individually for each specific patient, and it can be the same as after the primary operation, and very long, with the use of special means of rehabilitation.

results

The result of revision arthroplasty, in case of successful operation and a properly selected rehabilitation regimen, does not differ from the result of primary arthroplasty - normal movements in the joint (sometimes with some limitations) of the support ability of the leg or normal operation of the arm are restored.

4. Personal experience

In my early years as an orthopedic surgeon, revision surgeries were rare. As rare cases, they have always attracted my attention and aroused interest, so participation in such operations has always been a priority for me.

As an assistant to professors and associate professors, I gradually gained some experience, and by analyzing scientific data from the literature and conference materials, I got acquainted with modern achievements in revision surgery.

Since 2007, I started performing revision surgeries on my own, and in recent years I have had to do 30-40 revision surgeries a year.

5. Cost

Quota

Some institutions have the opportunity to issue a quota for revision arthroplasty and for treatment, thus, you will not have to pay, however, the waiting time for hospitalization does not always fit into the optimal terms for the operation, and the choice of implants available for use under quotas may not be enough to install the most suitable endoprosthesis - doctors have to improvise on the go, trying to solve the problem with the means at their disposal.

However, in order to fulfill necessary operation endoprosthetics, there are other ways.

CHI

Go to the Federal Office Clinic medical and social expertise perhaps with only a passport, compulsory medical insurance policy(of any region!) and the results of the preoperative examination. In this case, all treatment (hospitalization, surgery, medicines, rehabilitation), with the exception of the implants necessary in some cases, are paid by the policy. Also, hospitalization on a commercial basis is possible in this clinic.

Cost in a private clinic

The cost of a revision operation private clinic, as a rule, exceeds the cost of the primary arthroplasty operation. A longer stay in the clinic, a longer duration of the operation, and more expensive revision endoprostheses lead to an increase in the price. The price of the latter can exceed the price of the usual two or more times.

However, in some cases their use is not required, and the complexity and duration of the operation is not so high. The cost of treatment in this case can be even less than with a conventional endoprosthetic surgery. The cost of primary arthroplasty operations can be found in the relevant articles (see, etc.). Palagaeva Nina

Endoprosthetics of the hip joint

Reception and treatment of patients is carried out at the clinic of the Federal State Budgetary Institution of the Federal Bureau of Medical and Social Expertise at Ivan Susanin Street, 3 ().

Joint arthroplasty is an operation to replace an injured element with an artificial prosthesis, which is characterized by complexity and duration.

Allocate:

• total (characterized by a complete change of all articular parts, performed in case of coxarthrosis, necrosis of the head of the bone, rheumatoid arthritis, with grinding of the femoral neck, malignant formations);
• single cavity (replacement of a certain part of the joint);
• revision (repeated, associated with deformation or wear of the installed prostheses).

The device of revision endoprostheses

Attachment of endoprostheses can be carried out by cement, cementless and combined methods, the choice of which is determined by the experience of the operating doctor, as well as the age and lifestyle of the patient.

Embedded implants differ from each other:

• a structural feature of the calyx (a component that replaces the articular cavity. Its structure helps to properly distribute the load, prevents loosening);
• elements with a porous surface (gradually, the bone grows into the prosthesis, due to which the structure is well fixed).

Indications for revision surgery

Repeated arthroplasty is prescribed if:

• dislocation and dysfunction of the joint due to incorrect installation of the prosthesis or non-compliance with recommendations regarding the physical activity of the patient;
• wear of a foreign component associated with excessive overloads of the operated joint;
• aseptic loosening of a non-infectious nature;
• periprosthetic infection (in this case, the process of changing the endoprosthesis is carried out in two stages: the old implant is removed, the adjacent tissue is completely cleaned, then the replacement element is introduced);
• prosthesis fracture;
• an allergic reaction, the cause of which may be the composition of the artificial joint.

It is impossible to conduct a revision of the endoprosthesis in the hip joint in the presence of the following defects and contraindications:

• device infection;
• destruction and severe deformation of surrounding bone tissue;
• inflammatory process in the joint (or in the presence of damage);
• heart failure (chronic, decompensated, acute);
• pathology of the respiratory system;
• disorders in the liver and kidneys;
• infectious diseases of various nature;
• paralysis (paresis on the side where the endoprosthesis is planned to be installed);
• osteoporosis (in a pronounced form);
• vascular pathology in the legs;
• obesity (3-4 degree).

Dislocations in an artificial joint

The disease occurs in people who have an incorrect arrangement of parts of a non-native joint. Patients who do not comply with the motor regimen after an injury or surgery on the lower extremities are susceptible to it.

You can prevent the disease if you remove the provoking factor and regularly follow all the recommendations of the attending physician.

Material wear

When the components of the joint are rubbed, isolated particles of material are formed, which contribute to the unsuitability of the prosthesis.

Endoprosthesis instability

Aseptic instability (failure) knee joint- this is a violation in the operation of the implant components, in which changes occur in the metabolic processes in the bones located around.

This leads to improper functioning of the hip joint. Under the influence of small particles, a gradual loosening of the prosthesis itself occurs.

Dysfunction can be diagnosed by:

• pain (aching nature) that occurs during movement (and at rest);
• weakness in the legs;
• inability to fully support the limb.

Additionally carry out:

• x-ray examination of the affected area;
• dual-energy densitometry according to the program "Endoprotez" with an assessment of bone density in 7 Gruen zones;
• analysis of indicators of metabolic processes in bones.

Endoprosthesis infection

May occur during an artificial joint placement procedure.

There are types of infection:

• acute postoperative (develops during the first month after surgical manipulation);
• late chronic (observed in the interval up to a year);
• acute hematogenous (occurs after 12 months).

Treatment of pathology involves the complete cleaning and disinfection of the endoprosthesis, as well as tissues located around.

Signs of infection (assessed in combination):

• limited swelling;
• pain (local);
• increased body temperature (local);
• increased heart rate;
• rapid breathing;
• excess (or reduced) content of leukocytes (over 12×10, below 4×10).

Fracture of the bone at the fixation site

Periprosthetic fracture is caused by trauma. This problem is solved by restoring (for this purpose, osteosynthesis is carried out) of an already installed device or by its complete replacement. In case of complex injury, the bone is reconstructed using additional mechanisms and devices (special plates).

Incorrect initial setting

As a result of the incorrect location of the artificial joint, there are:

• pain syndrome;
• dislocations;
• limited motor function;
• difference in limb length.

The inaccuracy of the initial prosthetics is due to the lack of professionalism or the mistake of the surgeon who performed the operation, and is also provoked by the patient's overweight.

Initially, poor placement of the femoral endoprosthesis is the reason for a second surgical intervention to reinstall the foreign implant.

Breakage or destruction of endoprosthesis elements

Occurs due to physical trauma, improper initial installation, or due to aging and wear of the components of the endoprosthesis due to its long use, as well as the poor quality of the starting material.

The problem is solved by performing a second operation and replacing the defective element.

Allergic reactions to the endoprosthesis

When choosing an artificial joint, you need to evaluate its ability to cause allergies. allergic reactions caused by the components that make up the prosthetic material. These are:

• nickel;
• chromium;
• molybdenum;
• cobalt;
• tungsten;
• aluminum;
• manganese;
• vanadium.

Neutral compounds are ceramics, ultra-high molecular weight polyethylene. They are widely used during manipulations for the installation of a primary prosthesis and endoprosthetics. If an allergy occurs, it is necessary to remove the old endoprosthesis and install a new one.

Preparing for the operation

The period of preparation for surgical intervention includes the development of a detailed action plan by the attending surgeon, taking into account risk factors, contraindications, unforeseen situations (the need for blood transfusion, etc.).

The preparatory stage also includes comprehensively informing the patient about the essence of the upcoming procedure, the conditions for its implementation, etc.

Features of the operation

The main differences between repeated prosthetics is to carry out:

• taking the patient's bone tissue and installing it in a place for fixing the prosthesis (this contributes to the reliability of its fixation);
• thorough cleaning of the joint fragment under the prosthesis from foreign particles (cement or bone fragments);
• installation of drainage to ensure a full outflow of contents from the wound;
• stitching (layered);
• application of an aseptic dressing.

Possible Complications

When performing endoprosthesis replacement, the possibility of adverse consequences is not excluded:

• infection on the surface skin(inflammatory process, accompanied by pain, redness, swelling); in case of its manifestations, measures are taken for additional disinfection, replacement of the prosthesis, appropriate medication is prescribed;
• displacement of the structure;
• weakening of the muscular apparatus (leads to weakness of the limbs, differences in their development, differences in size).

Postoperative period

After the surgical operation the following steps should be taken (they will help the patient recover):

• provide the patient with oxygen (using a mask);
• regularly inject anti-inflammatory, painkillers, antibiotics;
• do special breathing exercises;
• monitor vital signs;
• during the rehabilitation period, you need to regularly visit the surgeon for examinations, follow the recommendations regarding the distribution of motor loads;
• perform a set of movements developed by the doctor, provided physical therapy(twice a day).

The cost of the procedure and quotas for CHI

The cost of arthroplasty is quite high and exceeds the cost of primary prosthetics.

This is due to:

• duration of inpatient treatment;
• the complexity of the reoperation;
• the use of expensive devices (made of high quality and high-tech materials);
• the use of anesthesia;
• postoperative care and follow-up.

It is possible to prevent primary trauma to the prosthesis if:

• avoid impacts and fractures of implanted joints;
• properly distribute physical activity;
• perform therapeutic gymnastic exercises;
• choose a doctor with extensive experience;
• use implants made of high quality materials from trusted manufacturers;
• follow the recommendations for the passage of the rehabilitation period;
• avoid overloading artificial components;
• Give your joints the rest they need.

Replacement of the prosthesis in the Moscow Pirogov National Medical and Medical Center can be done free of charge (excluding rehabilitation).

Full title:

Revision hip arthroplasty

Slobodskoy A.B., Badak I.S., Voronin I.V., Dunaev A.G., Bystryakov P.A. GUZ Saratov regional clinical Hospital(Director of the hospital - Tyapkin I.A.)

Numerous publications recent years convincingly prove the fact that today arthroplasty is the most effective method in the treatment of severe injuries and diseases of the hip joint (1, 4, 5, 7, 8, 9, 11). The number of primary endoprostheses is steadily increasing year by year. This is due to both an increase in the incidence of the hip joint and the number of injuries leading to arthroplasty (3, 6, 12, 14, 17). In proportion to the number of primary endoprostheses, the number of revision endoprostheses is also growing, which is due to a large number of reasons. Among the numerous criteria for assessing the quality of a particular implant, methods of surgical support, it is revision arthroplasty that is the most accurate and multifactorial assessment of any primary arthroplasty. It is this operation, as well as the timing of its implementation, that fairly objectively assess the quality of the primary construction, the “lifespan of the endoprosthesis”, possible defects in the primary operation, the correctness of the assessment of the primary diagnosis and comorbidity of the patient, as well as many other criteria (3, 6, 7 , 10, 13, 15, 16).

Purpose of the study.

To analyze the results of revision hip arthroplasty in the period from 1 to 6 years after the operation, to determine the features of surgical support after various types of primary operations in various anatomical situations.

Materials and methods.

In the period from 1996 to the present, under our supervision there were 1226 patients who underwent 1363 operations of primary hip arthroplasty. 137 patients were operated on from 2 sides. 511 men were treated, 715 women were treated. The age of the patients was from 18 to 94 years. Of these, under 25 years old - 18; from 26 to 40 years old - 158; from 41 years old to 60 years old 472; and older than 60 years 578 patients. As implants for primary hip arthroplasty, the endoprosthesis ESI (Russia) was used in 696 cases, Zimmer (USA) in 545, De Pue (USA) - 98, Seraver (France) - 18, Mathis (Switzerland) - 6. Cementless fixation endoprosthesis components were used in 582 operations, hybrid in 499 and fully cemented in 282 cases. In the same period, we performed 111 revision hip arthroplasty in 106 patients. In 5 cases, the revision was performed on 2 sides. The ratio of primary and revision arthroplasty operations was 1:12. Men 49, women 57. The age of patients is from 42 to 81 years. The time between primary and revision operations ranged from 2 months. up to 17 years old. Indications for revision arthroplasty and the number of operations performed are presented in Table. one

Tab. one
Reasons for Revisions of the Hip Endoprosthesis*

* Operations in which primary arthroplasty was performed in other medical institutions are noted.

From the analysis of the table. Table 1 shows that the largest number of revisions of the hip joint was performed after primary arthroplasty according to Sivash (56.8% of operations). 10.8% of surgical interventions were performed due to the failure of endoprostheses of unknown manufacturers, and often “self-made”, unlicensed designs. In 9.9% of cases, the reason for the revision was incorrect installation of the endoprosthesis components during the primary operation, which was manifested by pain, impaired walking biomechanics, and recurrent dislocations of the endoprosthesis head**.

The average terms for performing revision arthroplasty after primary hip arthroplasty, as well as the minimum and maximum terms of the "life of endoprostheses" are presented in Table. 2

Tab. 2
Terms of revision of the hip endoprosthesis

** this paper does not consider cases of endoprosthesis revisions associated with purulent complications

From the analysis of the table. Table 2 shows that the average terms of revision operations, as well as the minimum and maximum terms of the "life of the endoprosthesis" in primary endoprosthesis with modern implants from ESI, Zimmer, Biomet, De Pew are quite long and range from 11.3 to 12.7 years. These terms are much lower when Sivash endoprostheses (3.7±2.9) and Altimed (1.5±0.8) are used in primary operations. The use of improvised designs from unknown manufacturers led to revisions within 1 year or earlier.

Features of revision interventions for various primary arthroplasty.

Revision after primary endoprosthetics according to Sivash.

When performing a revision operation, we used either the old approach or the anterior-external Harding approach, depending on the condition of the soft tissues and the severity of the cicatricial process. When examining the trochanteric region, it was found that in more than half of the cases, the key had migrated. The greater trochanter was in place and fused with the femur only in 8 cases (12.7% of the total number of revisions of Sivash endoprostheses). In all other cases, it lay freely on the outer surface in the region of the gluteus medius muscle, having a connection with the femur only through the scar tissue (Fig. 1). Depending on the specific anatomical situation, the greater trochanter was either synthesized to the revision stem or removed. It is advisable not to remove the key of the endoprosthesis immediately, since it is easier to remove the stem of the endoprosthesis with its help.

The removal of the Sivash endoprosthesis, which is one-piece, was started with a cup. It was characteristic that the cup of the joint, in almost all cases, was overgrown with powerful osteophytes and cicatricial adhesive tissue and was rather difficult to stand out. However, after the removal of the latter, it was freely removed from the acetabulum. We practically did not observe signs of osseointegration on the cup. On the contrary, in most cases, the acetabular component was covered with connective tissue membranes, granulation and scar tissues, which was evidence of its instability (Fig. 2). Thus, during the revision surgery, we observed that the cup of the Sivash endoprosthesis was, as it were, in the bone-scar shell, which did not provide its rigid fixation. Osseointegration with the walls of the acetabulum was minimal or non-existent. The pedicle of the Sivash joint, due to its round shape and distal fixation system, was removed freely, often without special tools. Just like the acetabulum, the medullary canal was filled with fibrous, granulation and scar tissues, which were a “layer” between the joint pedicle and the inner surface of the medullary canal. We did not observe signs of osseointegration in the region of the endoprosthesis stem. In 19 cases (30.2% of the total number of revisions of Sivash endoprostheses), a fracture of the prosthesis leg in the “window” area was noted (Fig. 3). In these cases, the distal fragment was removed through additional longitudinal “cusps” in the femoral shaft.

In 11 patients, during the removal of Sivash endoprostheses in the area of ​​the joint neck, an accumulation of fluid (up to 100-200 ml) was found, cloudy-gray, sometimes with a greenish tint, odorless. For such patients, we limited ourselves to the removal of endoprostheses and a course of antibiotic therapy. In bacteriological cultures, the liquid in all cases turned out to be sterile. We performed endoprosthesis replacement in these patients after 4–5 months. after the first operation.

In 52 patients previously operated on according to Sivash (82.5% of all those operated on according to this technique), thinning and, to varying degrees, defects in the walls of the acetabulum were noted during revision operations. Thus, bone defects (according to the W. Paprosky classification) of type 2 A were observed in 9 patients, 2 B - in 29, 2 C - in 11, 3 A - in 3. In these patients, different kinds plastic interventions on the acetabulum, Bursch-Schneider anti-protrusion rings and Muller support rings.

Revision after primary arthroplasty according to Altimed.

During revision arthroplasty of Altimed endoprostheses, we noted the following features. In all cases, the cementless threaded cup, after being freed from scar tissues and the liner removed, was unscrewed completely freely, without special tools. The polyethylene part of the acetabular component of the endoprosthesis with titanium coating, due to which the fusion with the bone was supposed to occur, lay freely in the acetabulum, without connection with the cup. We did not observe any signs of osseointegration in the region of the cup itself and the titanium-coated polyethylene part. The removal of the leg was performed with special instruments without any problems after the release of its proximal part from osteophytes and scar tissues. On the removed legs of Altimed, we did not observe integrated bone tissue in any case, even in the area of ​​porous inserts in the proximal part. The bone marrow canal, after the removal of the pedicle, was a cavity filled with scar tissue, after the removal of which a sclerotic thinned non-bleeding bone tissue was exposed. In 3 cases, after the removal of Altimed endoprostheses, due to bone defects in the area of ​​the acetabulum, Muller support rings were used. Some publications provide data on Altimed pedicle fractures after primary operations (2).

For the operation in 92 patients, cemented and cementless revision stems from ESI (Russia) and in 19 cases a Wagner SL revision hip stem from Zimmer (USA) were used. ESI revision legs of a tetrahedral shape, with a proximal fixation system. The shape of the stem allows you to tightly fill the bone marrow canal, compensate for defects in the proximal femur, and, if necessary, lengthen the leg. Technological holes in the metaepiphyseal region of the endoprosthesis allow synthesizing the greater trochanter or strengthening the joint using myofascioplasty.

Research results and discussion.

The data of clinical and radiological examination of 88 patients who underwent revision hip arthroplasty in the period from 1 to 5 years were analyzed. The analyzed group included 50 women and 38 men. Primary surgeries were performed for idiopathic coxarthrosis in 17 patients, for dysplastic coxarthrosis in 28 patients, with aseptic necrosis of the femoral head, 19 patients were treated, fractures of the head and neck of the femur - 14, and false joints and ununited fractures of the femoral neck - 10. Sivash endoprostheses, ESI endoprostheses - 5, Zimmer - 6, Altimed - 4, De Pew - 2, Biomet - 2, unknown manufacturers - 10 were used in 59 operations of primary hip arthroplasty. Sivash's endoprostheses were self-made, from unknown grades of titanium or alloys. ESI revision endoprostheses were implanted in 79 patients, Zimmer cementless revision stems ZMR in 9.

To assess the statistical significance of the data obtained, methodological approaches based on the evaluation of the ?2 criterion were used, and the error probability of the Fisher criterion was calculated, which was significantly less than the specified value.

Clinical assessment The results of treatment were carried out according to the Harris evaluation scale (Table 3) for the hip joint (Harris W.H., 1969: Evaluation System of the Hip).

Tab. 3
Results of treatment of patients after revision hip arthroplasty (according to Harris)

Analyzing the clinical results of treatment of patients who underwent revision hip arthroplasty in the period from 1 to 5 years, it was found that excellent and good results in the above terms were observed in 75.0% of patients, and satisfactory in 18.2%. Unsatisfactory results occurred in 6 patients. Four of them - due to the development of deep suppuration in the area of ​​the endoprosthesis and four due to persistent pain in the postoperative period.

Complications.

To postoperative complications complications of a purulent-inflammatory nature, postoperative dislocations of the endoprosthesis head, periprosthetic fractures, neuropathies, and thromboembolic complications were attributed (Table 4).

Tab. four
Postoperative complications after revision hip arthroplasty

Analyzing the nature of complications after revision arthroplasty, it can be noted that the most common (4.5%) complications were of a purulent nature. In all cases, they developed in the late postoperative period (from 4 months to 3 years after surgery). Treatment of purulent complications was carried out according to well-known methods and in 2 cases ended with the removal of the endoprosthesis. Dislocations of the endoprosthesis head were observed more often than after primary endoprosthesis replacement (4.5%). Of these, in 3 patients they occurred in the first days of the postoperative period, and in one case, dislocation occurred after 6 months. after surgery due to a violation of the patient's motor regimen. The dislocations that occurred in the early postoperative period were corrected conservatively, and the dislocation that occurred 6 months later was repaired openly. Two patients were diagnosed with neuropathies and non-severe forms of PLA, which were stopped by conservative measures and did not affect the outcome of treatment. A periprosthetic fracture of the femur occurred in a patient after revision arthroplasty 8 months later. after surgery and is associated with additional trauma. In this case, osteosynthesis was performed with a plate, screws and cerclage wire. Revisions of the endoprosthesis components were not performed. Additional immobilization was not required. The fracture consolidated at the usual time.

Clinical example 1.

Patient F., 68 years old, was admitted to the orthopedic department of SarOKKB on 12.05.2006. aseptic necrosis of the femoral heads, secondary coxarthrosis 2 tbsp. Instability of Sivash endoprostheses. Pain syndrome. On May 15, 2006, an operation was performed - total arthroplasty of the left hip joint with a cement ESI endoprosthesis; Postoperative period flowed smoothly. The patient became active on the 2nd day after each operation. Extract on the 10th day after the 2nd operation. By this time, the patient was quite adapted to walking on crutches, including stairs. Homeostasis indicators at the time of discharge were satisfactory. The time of observation of the patient is 4 years (Fig. 4). Pain in the hip joints do not bother, the function is satisfactory. Walks without additional support. Harris score - 82 points. Satisfied with the results of the operation.

Clinical example 2.

Patient T., 64 years old, was admitted to the orthopedic department of SarOKKB on April 10, 2006. Diagnosis: condition after total arthroplasty of the right hip joint according to Sivash (2004). about aseptic necrosis of the head of the right femur, secondary coxarthrosis 2 tbsp. Sivash endoprosthesis instability, pedicle fracture, pain syndrome. On April 12, 2006, an operation was performed - total revision arthroplasty of the left hip joint with a cemented ESI endoprosthesis. The postoperative period proceeded smoothly. The patient became active on the 2nd day after the operation. Discharge on the 12th day after the operation. By this time, the patient was adapted to walking on crutches, including stairs. Homeostasis indicators at the time of discharge were satisfactory. The time of observation of the patient is 4 years (Fig. 5). Pain in the operated joint does not bother, the function is quite satisfactory. Walks with a cane. Harris score - 80 points. Satisfied with the results of the operation.

Clinical example 3.

Patient K., aged 52, was admitted to the orthopedic department of SarOKKB on September 15, 2008. Diagnosis: condition after total arthroplasty of the left hip joint with an endoprosthesis of unknown design (2004), total instability of the endoprosthesis components. Deep suppuration in the area of ​​the endoprosthesis (2005), removal of the metal structure. Defect of the proximal part of the left femur, defect of the roof and bottom of the left acetabulum. Purulent process did not recur for 3 years. On September 17, 2008, an operation was performed - total revision arthroplasty of the left hip joint with a cemented ESI endoprosthesis using a Muller support ring. The postoperative period proceeded smoothly. Discharge on the 10th day after the operation. By this time, the patient was adapted to walking on crutches, including stairs. Homeostasis indicators at the time of discharge were satisfactory. The observation time for the patient is 2 years (Fig. 6). Pain in the operated joint does not bother, the function is quite satisfactory. Walks with a cane. Harris score - 77 points. Satisfied with the results of the operation.

Conclusions:

1. Revision hip arthroplasty, like any reoperation, is much more complicated and problematic than primary hip arthroplasty. Violations of normal topographic and anatomical relationships in the hip joint area, massive cicatricial adhesions, powerful osteophytes, against the background of bone mass deficiency in the acetabulum and proximal femur, significantly complicate both planning and the operation itself.
2. Revision hip arthroplasty is a non-standard and purely individual operation in each specific case. When preparing for it, it is necessary to plan various options for its implementation, a possible transition from one of them to another, the use of a wide variety of materials and metal structures, and a high risk of intraoperative complications.
3. The use of modern implants and other additional structures for revision hip arthroplasty, as well as a strictly individual selection of the latter, allows obtaining good functional and anatomical results for a long time.