Endoprosthetics of joints

Endoprosthetics of the joints are considered one of the most effective methods of surgical treatment of patients with rheumatological diseases. This operation has become an integral part of restorative treatment of patients with rheumatic pathology and musculoskeletal injuries, since it not only allows to stop pain syndrome, but also returns functional activity, improves the quality of life.

The urgency of this method of surgical treatment is due to the frequency and nature of joint damage. More than 60% of patients with rheumatic diseases are involved in the process of lower limb joints. Clinical or radiographic evidence of hip failure is found in 36% of patients with rheumatoid arthritis, and the average age of patients at the time of surgery is 42 years. Endoprosthetics of the joints are also necessary for 5-10% of patients with systemic lupus erythematosus if they develop aseptic necrosis of the femoral head, most often bilateral. This process occurs, as a rule, at a young age, accompanied by severe pain syndrome, restriction of movement and decreased functional activity.

In the United States, juvenile rheumatoid arthritis is diagnosed every year in 100,000 children, while the hip joint is affected, according to various authors, in 30-60% of these patients. The decrease in functional activity resulting from this pathology leads to serious psychoemotional problems in children and adolescents due to their forced isolation and dependence on outside help.

In connection with this, RH, such as rheumatoid arthritis, juvenile chronic arthritis, SLE, ankylosing spondylitis. Occupy a leading position among indications for joint replacement.

[1], [2], [3], [4]

What is the endoprosthesis replacement for joints?

The purpose of arthroplasty is to restore the function of the affected limb. This is achieved by eliminating the pain syndrome and increasing the volume of movements. Restoring the functional state of the patient, perform the main purpose of arthroplasty joints - improve the quality of life. This is especially true in patients with RA, SLE, juvenile chronic arthritis, since most of them are young people of working age, for whom a return to a full active life is the key to successful treatment.

Indications for arthroplasty of joints

In determining the indications and contraindication to the operation of arthroplasty, the following factors should be assessed:

• intensity of pain in the joints:
• degree of severity of functional disorders;
• changes in the X-ray study;
• information about the patient (age, sex nature of previous operative treatment, somatic state).

When determining the tactics of treatment, the crucial stage is the stage of the pathological process. The main clinical sign of involvement of joint surfaces is the severity of pain. In this case, the pain is accompanied by the corresponding functional disorders and radiologic signs, which are most pronounced in the final stages of the disease. Often when examining patients, the discrepancy between the clinical picture and the severity of radiological changes is revealed. In this case, justifying the need for an operation is much more difficult. In this situation, the intensity of pain is considered the leading criterion for determining indications for arthroplasty. However, with RA, the intensification of pain may indicate an exacerbation of the disease. All this requires a comprehensive examination of patients in a specialized department, and surgical intervention should be performed in the remission phase.

The violation of limb functions due to the defeat of the articular surfaces, along with the severity of the pain, is considered one of the main indications for arthroplasty of the joints. In this regard, important systems of quantitative assessment of the state, allowing you to provide changes in points.

One of the most common systems for assessing the functions of the hip structures is the Harris evaluation system. When the number of points is less than 70, the hip replacement with an endoprosthesis is shown.

The most common system for assessing the condition of the knee is the system described by Insall, which includes a characteristic of the pain syndrome and walking indicators. In addition, the functions of the most affected articular surfaces, the degree of deformity of the limb are evaluated. It should be noted that these methods allow not only to assess the functions before the operation, but also the results of arthroplasty in the early and late postoperative period, as well as the dynamics of recovery and stabilization of the musculoskeletal function.

In addition to the above, there are other approaches and methods that allow to give a quantitative assessment of the state of the musculoskeletal system. In this regard, in order to obtain a more versatile evaluation of functions, it is desirable to use several approaches.

At present, the patient's age is not considered a criterion determining the possibility of joint replacement. More important is the assessment of the patient's somatic state, his activity, lifestyle, needs, desire to lead an active life.

Thus, it is possible to single out the following indications for arthroplasty of joints.

• The expressed painful syndrome to infringement of functions of a finit at an inefficiency of conservative treatment and revealing of radiological changes.
• Osteoarthrosis III-IV radiographic stage.
• Hip or knee injury in rheumatoid arthritis, juvenile chronic arthritis, AS and other rheumatic diseases with radiological and bone-destructive changes.
• Aseptic necrosis of the head of the femur with progressive deformation of the head.
• Aseptic necrosis of the condyles of the tibia or femur with progressive valgus or varus deformity.
• Changes in the hip joint with radiographic signs of protrusion of the bottom of the acetabulum.
• Clinically revealed limb shortening on the side of the affected joint surfaces in combination with radiological changes.
• Contracture, caused by detectable x-ray-bone-destructive changes.
• Fibrous and bony ankylosis.
• Post-traumatic changes, causing the violation of the support function and the development of pain syndrome.

Indications for endoprosthetics of metacarpophalangeal joints are:

• pain in the joint, which is not amenable to conservative treatment;
• deformation in the metacarpophalangeal joint:
• subluxation or dislocation of proximal phalanges;
• Ulnar deviation, which persists with active extension;
• identification of second and more degree of Larsen degradation during X-ray examination;
• the formation of contracture or ankylosis in a functionally unfavorable position;
• functionally unprofitable arc of movements (arc of motion);
• unsatisfactory appearance of the brush.

How will I prepare for arthroplasty?

With preoperative preparation and postoperative management of patients with rheumatological diseases, orthopedists have a number of problems associated with:

• systemic manifestations of the underlying disease;
• reception of BPO;
• anesthesia difficulties;
• technical difficulties:
• concomitant osteoporosis;
• simultaneous defeat of many articular surfaces.

One of the systemic manifestations of rheumatic diseases is anemia. Moreover, even long-term treatment in the pre-operative period sometimes does not give tangible results. An indispensable condition for joint replacement is the transfusion during and after the operation of an adequate amount of plasma and erythrocyte mass, as well as reinfusion of one's own blood.

In patients with rheumatoid arthritis, cardiovascular disorders are more frequent than in patients with osteoarthritis. In this regard, rheumatoid arthritis requires a more thorough examination of the cardiovascular system to determine the operational risk and conduct adequate preoperative preparation.

When planning the surgical intervention, it is necessary to take into account the medications taken by the patient. There is no convincing evidence of the negative effects of DMARD, such as methotrexate, leflunomide, TNF-a inhibitors, on the course of the postoperative period. However, due to the toxicity of these drugs, and also to reduce the risk of developing infectious complications, in most cases they are canceled one week before the operation and for the whole period of wound healing.

With long-term admission of glucocorticosteroids, atrophy of the adrenal cortex is observed, therefore, such patients need careful monitoring during the operation and in the early postoperative period. If necessary, pulse-therapy is performed.

Difficulties in conducting anesthesia are associated with the peculiarities of the course of rheumatological diseases. For example, with juvenile rheumatoid arthritis, the lesion of the mandibular joints in combination with micrognathia can significantly complicate intubation and make it difficult to restore breathing after intubation. The cervical spine with rheumatoid arthritis is affected in 30-40% of cases. Usually the process is asymptomatic, but because of the rigidity of the cervical spine, there are often difficulties with intubation. In patients with instability C1-C2 at the manipulation of the neck during intubation, there is a danger of damage to the respiratory center. When spinal anesthesia is performed, difficulties can arise in connection with spine injury, ossification of the vertebral ligaments, for example in patients with ankylosing spondylitis.

Given the multiplicity of joint surface damage in rheumatological diseases, a thorough examination of the musculoskeletal system and functional condition is considered very important in order to determine the patient's ability to use additional support in the postoperative period. If the shoulder, elbow or wrist joints are affected, patients may have problems using crutches. In such cases, it is often necessary to perform operations first on the joints of the upper limbs. Large articular surfaces of the upper limbs, such as the shoulder and elbow, are replaced less often. With pain in the shoulder joints, it is necessary, as far as possible, to remove pain so that the patient can use an additional support.

In patients with multiple injuries of the musculoskeletal system, as a rule, pronounced atrophy of the muscles of the upper and lower extremities is observed both as a result of the pathological process itself, and because of limited mobility and adynamia. In addition, very often the soft tissue surrounding the joint is involved in the pathological process. The defeat of periarticular tissues leads to the fact that mobility and the achieved volume of movements in the operated joint are often less than one would expect with this type of surgical treatment. The involvement of many articular surfaces in the process often leads to the development of contractures, subluxations and stiffness, which complicates the recovery of functional treatment. In this regard, it is of great importance to participate in the rehabilitation of an experienced methodologist in physiotherapy.

An essential step in pre-operational planning is the evaluation of radiographs. Focusing on the x-ray images of the joint elements, select the type of endoprosthesis, determine the size of its elements, and plan the stages of surgical intervention. In addition, X-ray examination along with other methods, allows you to determine the indications for cement or cementless joint replacement of joints. When assessing the roentgenogram of the hip joint, the shape of the femur, the medullary canal of the femur, the acetabulum, the degree of protrusion of the acetabulum bottom, the severity of the dysplasia of the articular surfaces, the x-ray of the knee - the interrelation of its elements, the degree of bone destruction of the condyles, the severity of deformation.

Hip Endoprosthetics

To conduct surgical intervention the patient can be laid on his back or on his side. Variants of operational access are different, but most often use and consider the most typical anterior and posterior approaches. In the first case, surgical intervention can be performed by putting the patient on both back and side. When using the patient's back access, they are placed on their side.

During the operation, careful hemostasis is necessary due to anemia as a systemic manifestation of the underlying disease, as well as the undesirability of conducting blood transfusions in these patients.

An important step in the operation is the test hip adjustment and assembly of the endoprosthesis assembly. In this case, check the compliance of all elements of the endoprosthesis with each other, their stability, the correctness of the anatomical orientation of the elements relative to each other and the body axes, as well as the volume of movements, perform the dislocation test. Only after this, the final assembly of the femoral component and the endoprosthesis head is performed.

Endoprosthetics of the knee joint

Endoprosthetics of the joints are performed with a pneumatic turnstile on the thigh. Apply parapatellar access (external, often internal). An important stage of the operation is the removal of the pathologically altered synovium, which supports inflammation in the joint surfaces and the development of bone destruction. The preserved pathological synovial tissue can cause the development of aseptic instability by the endoprosthesis component.

The technique of setting resecting patterns, the subsequent selection of the required components of the endoprosthesis and their setting are considered typical for this operation. Differences are due to the peculiarities of the designs of different models and types of endoprostheses.

It is very important to achieve a knee ligament balance during the operation of arthroplasty. Developing with rheumatoid arthritis, valgus deformity leads to insufficiency of the internal ligamentous knee complex. In this regard, in order to achieve a good result during the operation, it is necessary to assess the condition of the ligament apparatus and its complete balancing.

[5], [6], [7], [8], [9]

Endoprosthetics of metacarpophalangeal joints

In arthroplasty, most patients use transverse access in the projection of the metacarpal heads. In this case, the most important in the operation of endoprosthetics of metacarpophalangeal joints is not the placement of the implants themselves, but the complex of interventions on the soft tissues surrounding the joint. For the elimination of sinitis, a synovectomy must necessarily be performed.

Next, we should evaluate the safety of the cartilage and, if joint replacement is performed, a proximal phalanx should be identified. In some cases, its rear cortical layer may have a defect, which should be taken into account when resecting the head. Usually, resection of the phalangeal base is not required. When forming channels, it is important to remember that the phalangeal channel is formed first, since its medullary canal is smaller than the metacarpal canal. This is true for metacarpophalangeal joints II, III and V.

It is also necessary to cut out ulnar portions of the posterior interosseous muscles with nearby ligaments. In the metacarpophalangeal joint II, this can cause the rotation of the finger, therefore, if correction of ulnar deviation can be performed without performing this procedure, one should avoid clipping of these muscles. Such manipulation is performed not only with arthroplasty of joints, but also with synovectomy, then (considering the time reserve), it is possible to transfer these tendons to the radial side of the adjacent finger. Since the deformation is caused by the ulnar displacement of the tendon of the extensor, they perform their radialisation in any way accessible to the surgeon.

[10], [11], [12], [13], [14], [15]

Operational characteristics

To assess the effectiveness of arthroplasty, joints are used both as tools for instrumental diagnosis (mainly radiography) and for multiple scales and questionnaires. According to X-ray images, the stability of the endoprosthesis, the correct location of its elements, the degree of their migration, the appearance and severity of osteolysis can be assessed. The intensity of pain is assessed by the patient himself on the visual analog scale, and by the doctor when checking the operation of the operated joint, if possible to load the operated limb, the need for additional support, while walking the stairs and for long distances. Only considering the set of factors, it is possible to give an objective assessment of the effectiveness of the operation performed.

After arthroplasty in patients with rheumatological diseases, many researchers note good long-term results: increased functional activity and pain reduction. It was shown that, 10 years after arthroplasty, most patients did not experience pain or pain were insignificant. However, it is believed that pain in patients with rheumatic diseases is the most variable symptom, and the restoration of functional activity is much worse than in patients with other pathologies, which is due to the polyarticular nature of the lesion and the systemic nature of the rheumatological disease. In this situation, it is not always possible to objectively assess the functional state of one particular joint.

Factors affecting the effectiveness of arthroplasty

The effectiveness of arthroplasty of joints is determined by a number of factors, such as:

• somatic state of the patient:
• activity of the disease and severity of systemic disorders;
• number of affected articular surfaces;
• the stage of defeat of the operated joint, the degree of its destruction and the severity of changes in the periarticular tissues;
• preoperative planning and selection of an endoprosthesis;
• an individually selected adequate rehabilitation program; qualification of medical personnel.

[16], [17], [18], [19], [20], [21], [22], [23]

Alternative methods

Alternative methods include arthroplasty, corrective osteotomy of the thigh and lower leg, arthrodesis. However, with the development of arthroplasty of joints, the improvement of models of endoprostheses indications for the use of the above methods are narrowed. For example, an isolated corrective osteotomy, whose goal is to change the axis of the load and unload the affected joint, has recently been performing single-implant arthroplasty of joints more often, and arthrodesis is used very narrowly and according to strict indications.

[24], [25], [26], [27], [28], [29]

Contraindications to arthroplasty of joints

Contraindications to arthroplasty of joints are determined taking into account the risk of intraoperative and postoperative complications, anesthesia risk. Take into account the patient's psychoemotional state, as well as the expediency of carrying out the operation in terms of further ability to active life.

The following main contraindications to surgical treatment can be distinguished.

• Unsatisfactory somatic state of the patient, the detection of severe concomitant diseases, significantly increasing anesthetic risk and the risk of intraoperative or postoperative complications.
• Detection of foci of infection both in the place of the planned surgical intervention, and remote.
• Mental disorders that do not allow the patient to adequately assess their condition and follow the postoperative regimen.
• Multiple lesions of soft tissues, which preclude operation of the operated limb and walking crutches after the operation.

The last contraindication for the operation of arthroplasty is not considered absolute. In this case, it is possible to consider variants of step-by-step surgical treatment with a preliminary restoration of the functions of other articular surfaces, which will allow the patient to recover the ability to stand and use an additional support for walking.

Contra-indications for endoprosthetics of metacarpophalangeal joints, in addition to general (skin condition, patient psyche, etc.), include:

• dislocated articular surfaces with a shortening of more than 1 cm or with a pronounced loss of cortical bone;
• joint structures with fixed deformation of the "neck of the swan" and limited bending in the proximal interphalangeal joint;
• destruction of tendons of extensors as a result of trauma or underlying disease.

It should be noted that the above contraindications are considered relative (except septic skin processes in the field of operation), i.e. The operation is possible, but the effect and consequences are poorly predictable. So, with the development of fibrotic ankylosis in the proximal interphalangeal joint, arthroplasty can be performed, but the brush functions will not, of course, be restored to the level that could be expected in patients with undisturbed movements.

[30], [31], [32], [33], [34], [35]

Complications after arthroplasty of joints

The most common complication after arthroplasty of joints is the appearance of instability of the endoprosthesis elements. Disturbance of bone tissue restoration in rheumatic disease, associated with the development of secondary osteoporosis - unfavorable factors in the implementation of arthroplasty.

It is known that the development of osteoporosis and the risk of instability of the endoprosthesis in rheumatic disease are due, on the one hand, to the effect of the underlying disease, the activity of the inflammatory process, reduced physical activity, the severity of functional disorders, and on the other hand, used for the treatment of drugs that inhibit local factors growth and disrupt the adaptation of bone to stress. In this regard, the risk of instability of the endoprosthesis elements in patients is increased. With the development of instability, clinically manifested by severe pains in violation of the limb's limb, in most cases, there is a need for revision arthroplasty.

Functional instability is associated with the mobility of the endoprosthesis under relatively small loads. At revision the amplitude of displacement can make from several millimeters to several tens of millimeters. Radiographically, instability is detected by the appearance of a bleaching zone between the implant (or cement) and the bone.

Data on the development of instability are very variable. In the study from 6 years after hip replacement, X-ray signs of instability of the acetabular component were found in 26% of cases, and in the femoral part in 8%. In another study, 8 years after endonothesis with cement, radiologic signs of instability were observed in 57% of patients. However, the changes detected radiological, do not always have clinical manifestations. Thus, in one study it was shown that in the period from 2 to 6 years after arthroplasty of the joints of 30 operated patients, none of the revision operations were performed, although small areas of resorption observed around 43% of the femoral and 12.8% of the acetabular components of the endoprostheses.

Other complications include:

• dislocation of the femoral component after total hip arthroplasty (submitted by different authors, the incidence of this complication is "about 8%);
• secondary infection (1-2% of cases);
• fractures of the femur and tibia are proximal and distal to the components of the endoprostheses (0.5% of cases):
• stiffness after knee arthroplasty (1.3-6.3% of cases);
• damage extensor mechanism (1,0-2,5% of cases).

Of the complications after endoprosthetics of the metacarpophalangeal joints, besides the infectious fracture of the implant, the development of silicone synovitis, the loss of the initially achieved volume of movements and the relapse of ulnar deviation should be noted.

[36], [37], [38]

Postoperative period

In the postoperative period from the second day, patients should begin to move: walk with crutches with a dosed load on the operated limb, and engage in physiotherapy exercises. It is necessary to start early active and passive movements in the operated joint, passive development of movements with the help of special devices. This is considered a guarantee of the subsequent good work of the limb.

To the day of discharge (but removal of stitches) the volume of movements in the knee should be at least 100, the patient should be able to fully serve himself, walk the stairs. After endoprosthetics of the hip joint in the postoperative period, there are temporary limitations in the movements (flexion, reduction, external rotation). These measures are necessary for the prevention of dislocation in the joint.

The rehabilitation period after arthroplasty of the metacarpophalangeal joints is about 6 weeks and includes occupational therapy, exercises with subjects, physical therapy, and the wearing of a dynamic tire.