Features hip arthroplasty in severe dysplasia types

Introduction

dysplastic coxarthrosis is among the most severe disease of the hip joint, its frequency is from 21 to 80% of all diseases of the last.

dysplastic coxarthrosis has its own characteristics, due to the young age of patients, rapid progression of the disease and the effect of the lowth from conservative treatment, expanding the indications for hip replacement is an urgent problem in modern orthopedics. Hip arthroplasty in dysplastic coxarthrosis, especially in severe types it is a complex and high-tech surgery.

In displastical hip are significant anatomical changes both in the acetabulum and in the proximal femur, these changes depends tactic surgery. In such cases it is difficult and sometimes impossible to perform preoperative planning in full.

In order to select tacticsand treatment and evaluation is important to have a common classification of this pathology. According to the International Classification of Diseases 10th Revision are three degrees of changes in the hip joint on the severity of dysplasia, subluxation and dislocation of the hip. However, the most frequently used in practical work classification Crowe (1979), Eftekhar (1978) andHartofilakidis (1988), since they are recorded in detail anatomical and functional changes in the hip joint. In our work we adhere to the classification of Crowe, since according to him, in addition to describing the state of the femoral head for depression may interest payment cranial displacement of the head. Thus, the first type is markedis proximal displacement of up to 50% of the height of the head, the second type - 50-75%, in the third - 75-100%, and the fourth type of head is displaced by more than 100%.

The most relevant in hip arthroplasty in severe forms of dysplastic coxarthrosis questions remain establishment of the acetabular component of the prosthetictnositelno its anatomical position, the use of bone grafting of the acetabulum roof, bringing down the thigh and reposition the prosthesis head.

The purpose of work - to optimize the tactics of hip arthroplasty in severe types of dysplastic coxarthrosis (see also).

Material and methode

The study is based on analysis of total hip replacement in patients with severe type of dysplasia (Crowe III, IV). It operated on 29 patients who underwent 38 hip replacements. In 9 patients underwent total hip replacement on both sides. CONVERSIONLADA patients are female: Among the patients were 28 women and one man. With hip dysplasia type Crowe III were 28 cases of type Crowe IV - 10 cases. The average age of patients was 44.2 years. Prostheses with cement-type fixation elements was used in 5 cases, uncemented - 29 and a hybrid - in 4 cases. Prostheses scementnym type of fixation used in cases where it was not possible to achieve stable fixation elements uncemented prosthesis type. Acetabular component was installed on the basis of press-fit fixation. Bone grafting of the acetabulum in the field of applied in 21 patients, accounting for 55.26%. Foot type of prosthesis chosen depending on the formy medullary canal of the proximal femur.

Results and discussion

The complexity of hip replacement in this condition due to the fact that it is necessary to eliminate the dislocation of the hip and install the acetabular component in the anatomical positionertluzhnoy depression. Much-stage hip distraction face developing serious complications from the neurovascular bundle, which can lead to negative results. On the other hand, underdeveloped acetabulum is not always possible to install the acetabular component prosthesis with complete overlap of bone tissue that canbe due to a deficit of bone acetabulum. Thus, according to NV Suburban, with types III and IV bone dysplasia deficit front edge higher than the back 2-3 times, and the vertical position of the acetabular component leads to accelerated abrasion of the polyethylene liner. When tilting the acetabular component to 56 ° polyethylene wear reaches 23.2%, whereas when the tilt angle of the acetabular component 50 ° deterioration reaches 16,3%.

Some authors do not seek to establish the acetabular component in anatomical position, thus avoiding the need for bone grafting, application of complex con- structed antiprotruziynihktsy contractile and osteotomies of the femur. Other authors solve the problem of shortage of bone tissue of the acetabulum using bone cement. According to AE Olejnik, AE Rags (2008), acetabular dysplastic coxarthrosis is variable so that does not allow to develop a special design for this disease.

We performed preoperatively someone drink-tomography of the joint in order to determine the state of the bone tissue of the front and rear pillars, the roof of the acetabulum. If you have a deficit of bone tissue, we performed bone grafting of the defect. The material for bone grafting is the femoral head, which is taken at endoprotezirovanii hip. Thus, the remote head and femoral neck were prepared graft shape defect responsible acetabulum, so that one side was a spongy cloth, the opposite side - the cortex of the femoral neck. The graft was placed in the defect columns or roof Islandrtluzhnoy cavity so that spongy tissue in contact with the bones of the pelvis, and the cortex was outside. After the transplant was carried out the screws that graft steadily fixed to the bones of the pelvis, and then formed a box cutter to the acetabular component prosthesis (Fig. 1B).

In addition, there is a problem with the reduction of the head of the prosthesis, as well as the possibility of failure of muscles, especially in limb lengthening of more than 3 cm. The reduction of the femoral head to the true position of the acetabulum is recommended to decide differently. Most surgeons prefer to contractile osteotomythe proximal femur. There are proponents of contractile femoral osteotomy in the distal [11]. There are advocates of skeletal drawing in pre-operating period or the Ilizarov fixator.

Our approach is as follows. When dysplastic coxarthrosis Crowe III, IV with reduced limbs to4 cm hip arthroplasty performed with simultaneous lengthening limbs. By shortening the limb 4-5 cm a one-time extension of the limb is fraught with complications from the neurovascular bundle, in addition, not always possible to perform a reduction of the head of the prosthesis, especially in patients who have already performed operational BMEvention on the hip in childhood. Therefore patients underwent contractility osteotomy of the proximal femur.

In cases where it is necessary to limb lengthening more than 5 cm, surgery was performed in two stages. The first stage was applied rod apparatus of external fixation with the introduction of rodsher pelvis and femur. Assembling the rod external fixation allows for a one-time extension of the limbs, is done while overlaying device under general anesthesia, and then within a few days continues to lengthen a limb and thus summed femoral head to the true acetabulum. After reachingI dismantled the target machine and after wound healing of the rods performed hip replacement.

The results of treatment of patients followed up in a period of 6 months to 5 years.

Clinical example. Patient M., born in 1947, was admitted to hospital with a diagnosis of left-hand driveit dysplastic (type Crowe IV) koksartroza 4 th century. The history: the age of 3 patients underwent surgery, which consisted of open reduction of congenital dislocation of the left hip. As time progressed, on which the patient sought help at the clinic. Fig. 1a shows ?? radiograph levogon the hip at the time of treatment in the clinic.

The examination of the patient is determined a significant limitation of movement in the left hip joint, the relative shortening of the left lower limb 6 cm. The clinic is the first stage in the pelvis and left thigh imposed rod external fixing device.

Gradually NizwaDan femoral head to the level of the true acetabulum (Fig. 1b), after which the unit is dismantled and underwent total joint replacement of the left hip joint prosthesis with cementless fixation type. During surgery defect acetabulum roof replaced avtotransplantatom taken from the femoral head (Fig. 1c). &Nbsp;

The functional outcome after 12 months of treatment are shown in Fig. 3.

Conclusion

acetabular component in total hip replacement in cases of severe dysplasia types neededIMO in the attempt to establish a true anatomical position of the acetabulum. In the presence of defects in the anterior, posterior columns, the roof of the acetabulum is a plastic avtotransplantatom with femoral head removed during arthroplasty.

Hip arthroplasty in dysplastic coxarthrosis with coabbreviated limb to 4 cm is possible in one step. By shortening the limb 4-5 cm is shown to perform joint replacement sokrotitelnoy osteotomy of the proximal femur. When unilateral shortening of more than 5 cm in order to prevent complications in the neurovascular bundle and facilitating reduction head prosthesisand before endoprotezuvannyam shown relegation of the femoral head to the level of the true acetabulum using a rod machine.