RU2803382C1 - Method of hip arthroplasty with simultaneous elimination of deformity of the proximal femur - Google Patents

Abstract

FIELD: medicine; traumatology and orthopedics.

SUBSTANCE: invention can be used for hip arthroplasty with simultaneous elimination of angular deformity of the proximal femur. After elimination of the angular deformity, both fragments of the femur are placed on the extracortical fixator Ortho-SUV, retreating two centimeters from the osteotomy line, to the outer part of which, at the same height, with the help of L-shaped fixators, they are mounted along a straight bar for five holes, placing them parallel to each other, end at an angle of 90° to the mechanical axis of the femur. Two threaded rods are passed through the extreme holes of the straight bars, placing them perpendicular to the straight bars with fixation with nuts. Then, by manipulating the nuts located on the threaded rods of the assembled structure, compression is created between the fragments of the femur until contact is reached in the osteotomy area. The femoral canal is treated with reamers and rasps until wedging, followed by implantation of the femoral component of the endoprosthesis using bone cement. After polymerization of the bone cement, the assembled structure is dismantled and the head is set into the previously implanted acetabular component.

EFFECT: method provides reliable primary fixation of the components of the standard femoral component of the endoprosthesis by holding fragments of the femur using the proposed method in one operating session.

1 cl, 5 dwg, 2 tbl, 2 ex

Description

The invention relates to medicine, in particular to traumatology and orthopedics, and can be used during total hip replacement in patients with acquired angular deformity or pseudarthrosis of the proximal femur.

The main causes of deformity of the proximal femur are post-traumatic (improperly healed fractures of the trochanteric zone and the upper third of the diaphysis), congenital (dysplasia), iatrogenic (various types of corrective inter- and subtrochanteric osteotomies), as well as due to metabolic disorders in bone tissue (Paget's disease ) (Tikhilov R.M. (ed.) Guide to endoprosthetics / edited by R.M. Tikhilov, V.M. Shapovalov. - St. Petersburg, RNIITO named after R.R. Vreden, 2008. - P. 380- 400)

One of the difficult problems when performing such operations is the selection of the optimal design, the difficulty of implantation and reliable fixation of the femoral component stem. In case of severe deformities of the proximal part (upper third of the diaphysis) of the femur, it is often necessary to perform an osteotomy, and sometimes surgical interventions should be divided into two stages (Roche O., Sirveaux F., Turell P., Gosselin O., D.: Adaptative femoroplasty in total hip arthroplasty for proximal femur deformity. Rev Chir Orthop Reparatrice Appar Mot. 2005 Feb; 91(1): 79-84).

There is a known method of hip replacement with angular deformation of the femoral diaphysis, which consists in the fact that after performing an osteotomy of the femoral neck, extended to the end surface of the distal medialized fragment of the femur and cutting off the plate of the greater trochanter, the medullary canal of the femur is treated with rasps. Next, a bone wedge is excised at the top of the diaphysis deformity and the dissected bone fragments are compared on a rasp. Afterwards, the femoral component of the “triclin” type prosthesis with diaphyseal fixation is implanted and the head of the prosthesis is set into the socket. Next, the severed plate of the greater trochanter is fixed to the femur, and the axis is corrected and compression is performed at the junction of the fragments with a transosseous wire AVF, which ensures restoration of the biomechanical axis of the limb, stable fixation of the diaphysis fragments on the endoprosthesis stem, and reduction of treatment time. (Method of endoprosthetics for angular deformity of the femur. Patent No. 2342912 of the Russian Federation. Published 01/10/2009)

However, a significant disadvantage of this method is the long period of use of the AVF, which requires careful care of the transosseous elements, increases the risk of infectious complications associated with inflammation of the exit sites of the transosseous elements, creates significant discomfort and reduces the patient’s quality of life for the entire period of wearing the AVF.

There is a known method of hip replacement in the presence of deformity of the femoral diaphysis, which involves the first stage of installing an endoprosthesis, immersing its stem to the level of the apex of the deformity of the femur with osteotomy of the greater trochanter area and fixation of its fragments with cerclage sutures. At the second second stage, osteosynthesis of the femur is carried out, the hip joint is stabilized and an osteotomy of the femur is performed at the level of the apex of its deformity distal to the leg of the installed endoprosthesis with subsequent restoration of the longitudinal axis of the segment. (Method of endoprosthetics in the presence of deformation of the femoral diaphysis. Patent No. 2538050 of the Russian Federation. Published 01/10/2015)

However, significant disadvantages of this method are the long period of use of AVF, limited choice of design and standard sizes of endoprosthetic legs suitable for implantation and the need for two-stage surgical treatment, which entails a longer period of postoperative recovery.

The objective of the invention is to develop a method for hip replacement in the presence of acquired angular deformity or false joint of the proximal femur, providing reliable primary fixation of the components of the standard femoral component of the endoprosthesis.

In order to identify the features of one-stage reposition and retention of osteotomized fragments of the proximal femur, an experiment was performed on plastic bones. One of the objectives of the experiment was to determine the optimal positions for installing extracortical Ortho-SUV fixators and subsequent installation of a repositioning unit, which must meet two basic requirements: not threaten damage to the great vessels, nerves and have optimal morphometric parameters (width, height, length, bone density and integrity ) for strong fixation of extracortical fixators Ortho-SUV. The diaphyseal part of the femur, distal to the lesser trochanter, has the greatest density and, accordingly, strength of bone tissue. Thus, in order to achieve adequate contact of the Ortho-SUV extracortical fixator with the cortical tube of the femur, they should be positioned distal to the lesser trochanter, two centimeters away from the osteotomy line. It should be noted that determining the optimal locations for installing the Ortho-SUV extracortical fixators is also necessary for performing subsequent stages of hip replacement, since during the final assembly of the repositioning unit, its components should not interfere with the manipulations and impede the view of the surgical area.

The proposed method is illustrated on a plastic model of the proximal part of the right human femur, corresponding in size to natural bones (Figure 1).

The technical result consists in ensuring reliable fixation of the femoral component of the endoprosthesis using bone cement after eliminating the angular deformity of the proximal femur by retaining fragments of the femur using the proposed method in one operating session.

The result of the invention is achieved due to the fact that the acetabular component is implanted and a wedge-shaped corrective osteotomy is performed at the level of the apex of the deformity. parts of which at the same height with the help of L-shaped clamps are mounted along a straight bar onto five holes, placing them parallel to each other, with their end faces at an angle of 90° to the mechanical axis of the femur; two threaded rods are passed through the outer holes of the straight strips, positioning them perpendicular to the straight strips and secured with nuts; then, by manipulating the nuts located on the threaded rods of the assembled structure, compression is created between the fragments of the femur until satisfactory contact is achieved in the osteotomy area, after which the femoral canal is processed with reamers and rasps until tightly jammed, followed by implantation of the femoral component of the endoprosthesis using a portion of bone cement, After polymerization of the bone cement, the assembled structure is dismantled and the head is repositioned into the previously implanted acetabular component.

The advantages of the proposed method include:

- elimination of angular deformity of the proximal femur and hip replacement in one surgical session;

- ease of assembly of the proposed design for holding fragments of the femur and the use of parts from the standard AVF set, which allows its use during total arthroplasty surgery without the use of special tools;

- creating compression between the fragments of the femur in order to prevent bone cement from entering the osteotomy area, which promotes further consolidation;

- creation of conditions for reliable primary fixation of the femoral component of the endoprosthesis in both fragments of the femur through the use of cement technology;

- no need to wear an AVF for a long time, which reduces the risk of infectious complications associated with inflammation of the exit sites of transosseous elements;

- the possibility of processing the bone canal of the femur with a reamer and rasp, followed by installation of the femoral component, achieved through the convenient location of the AVF components in the proximal femur.

- preservation of the muscles attached to the proximal fragment of the femur leads to a prognostically high risk of fusion of the osteotomy line and a satisfactory functional result after endoprosthetics.

- implantation of the femoral component using cement technology makes it possible to achieve primary rigid stability of the osteotomized fragments of the proximal femur and the endoprosthesis stem.

The illustrations show:

Fig.1. Plastic model of the proximal femur after corrective osteotomy at the apex of the deformity and installation of a fixation device, where 4 is osteotomy; 5 - proximal fragment of the femur; 7 - distal fragment of the femur; 8 - extracortical fixator Ortho-SUV; 9 - L-shaped clamp; 10 - straight strip with 5 holes; 11 - threaded rod; 12 - nut;

Fig. 2. Clinical example No. 1, radiograph before surgery, where 2 is the apex of the deformity; 5 - proximal fragment of the femur; 6 - angular deformity of the femur; 7 - distal fragment of the femur

Fig. 3. Clinical example No. 1, radiograph after surgery, where 1 - acetabular component, 4 - osteotomy; 5 - proximal fragment of the femur; 7 - distal fragment of the femur; 13 - cement femoral component; 14 - head.

Fig. 4. Clinical example No. 2, radiograph before surgery, where 3 - pseudarthrosis of the proximal femur; 5 - proximal fragment of the femur; 7 - distal fragment of the femur

Fig. 5. Clinical example No. 2, radiograph after surgery, where 1 - acetabular component, 4 - osteotomy; 5 - proximal fragment of the femur; 7 - distal fragment of the femur; 13 - cement femoral component; 14 - head.

The method is carried out as follows: during the hip replacement surgery, after performing the Harding approach to the hip joint, the acetabular component of the endoprosthesis 1 is implanted. After visualizing the apex of the deformity 2 or the false joint 3, a wedge-shaped corrective osteotomy 4 of the proximal part 5 of the femur is performed with the elimination of the angular deformity 6 ( Fig. 2). Next, on the proximal 5 and distal 7 fragments of the femur, they are installed using the extracortical fixator Ortho-SUV 8, at a distance of two centimeters from the osteotomy line 4. To the outer part of both extracortical fixators Ortho-SUV 8 at the same height, using L-shaped fixators 9, they are mounted along straight bar with 5 holes 10, placing their end perpendicularly at an angle of 90 degrees. to the mechanical axis of the femur and parallel to each other. Next, threaded rods 11 are inserted through the outermost holes of the straight strips 10, positioning them perpendicular to the straight strips 10 and fixed with nuts 12. Thus, a stable system is obtained from the components of the external fixation apparatus, which allows you to manipulate the nuts 12 located on the threaded rods 11 of the assembled structure, namely, by tightening both nuts 12 at the point of attachment of one straight bar 10 towards the opposite straight bar 10 in such a way as to create compression between the proximal 5 and distal 7 fragments of the femur to achieve satisfactory contact in the area of osteotomy 4, after which the femoral canal is processed using reamers and rasps until tightly jammed, then the cement femoral component of the endoprosthesis 13 is implanted. After polymerization of the bone cement, the assembled structure is dismantled. Next, a head 14 is installed on the cone of the femoral component of the endoprosthesis and reduction is performed into the previously implanted acetabular component 1 of the hip joint endoprosthesis.

Clinical example No. 1:

Patient P., 50 years old, was admitted to the clinic of the Federal State Budgetary Institution “National Medical Research Center for Traumatology and Orthopedics named after. R.R. Harmful” of the Ministry of Health of Russia with a diagnosis of Right-sided deforming coxarthrosis, stage 2. Fracture of the proximal part of the right femur healed with varus-antecurvation deformity. The patient underwent surgical treatment involving a one-stage corrective osteotomy of the proximal femur with elimination of angular deformity and retention of femoral bone fragments according to the method we propose, followed by total anti-hybrid endoprosthetics of the right hip joint.

On control radiographs of the right hip joint, taken the next day, a total endoprosthesis is visualized with good fixation of the cement femoral component and anatomically correct position of the fragments of the right femur (Fig. 3). The postoperative period proceeded without complications, the function of the operated hip joint was restored, partial support on the operated limb with the help of crutches from the first day after the operation for 3 months, then 2 months with a cane.

Control examinations were carried out after 3, 6 and 12 months. To assess functional results, the Harris Hip Score and Oxford Hip Score were used. The dynamics of restoration of the function of the right hip joint are reflected in summary table 1. There are no clinical and radiological data for instability of the endoprosthesis of the right hip joint.

Table 1. Clinical and functional results of patient treatment at follow-up examinations. before surgery 3 months 6 months 12 months Functional result according to the Harris Hip Score 44 points 82 points 88 points 92 points Functional result according to the Oxford Hip Score 15 points 38 points 40 points 42 points

Clinical example No. 2:

Patient P., 54 years old, was admitted to the clinic of the Federal State Budgetary Institution “National Medical Research Center for Traumatology and Orthopedics named after. R.R. Harmful” of the Ministry of Health of Russia with a diagnosis of Right-sided deforming coxarthrosis, stage 2. Tight pseudarthrosis of the proximal right femur (Fig. 4). The patient underwent surgical treatment consisting of a one-stage corrective osteotomy of the proximal femur with resection of the pseudarthrosis, elimination of angular deformity and retention of femoral bone fragments according to our proposed method, followed by total anti-hybrid arthroplasty of the right hip joint.

On control radiographs of the right hip joint, taken the next day, a total endoprosthesis is visualized with good fixation of the cement femoral component and anatomically correct position of the fragments of the right femur (Fig. 5). The postoperative period proceeded without complications, the function of the operated hip joint was restored, partial support on the operated limb with the help of crutches from the first day after the operation for 3 months, then 2 months with a cane.

Control examinations were carried out after 3, 6 and 12 months. To assess functional results, the Harris Hip Score and Oxford Hip Score were used. The dynamics of restoration of the function of the right hip joint are reflected in summary table 2. There are no clinical and radiological data for instability of the endoprosthesis of the right hip joint.

Table 2. Clinical and functional results of patient treatment at follow-up examinations. before surgery 3 months 6 months 12 months Functional result according to the Harris Hip Score 42 points 80 points 84 points 90 points Functional result according to the Oxford Hip Score 16 points 34 points 42 points 44 points

Claims (1)

A method of hip replacement with immediate elimination of angular deformity of the proximal femur, including implantation of an acetabular component and a wedge-shaped corrective osteotomy at the level of the apex of the deformity, characterized in that after eliminating the angular deformity, the extracortical fixator Ortho-SUV is installed on both fragments of the femur, retreating along two centimeters from the osteotomy line, to the outer part of which at the same height, using L-shaped clamps, they are mounted along a straight bar with five holes, placing them parallel to each other, with their ends at an angle of 90° to the mechanical axis of the femur; two threaded rods are passed through the outer holes of the straight strips, positioning them perpendicular to the straight strips and secured with nuts; then, by manipulating the nuts located on the threaded rods of the assembled structure, compression is created between the fragments of the femur until contact is achieved in the osteotomy area, after which the femoral canal is processed with reamers and rasps until jamming, followed by implantation of the femoral component of the endoprosthesis using bone cement, after polymerization of the bone cement, the assembled structure is dismantled and the head is repositioned into the previously implanted acetabular component.