RU2367367C2 - Plasty technique for fenestrated defects of acetabular roof in hip replacement - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to traumatology and orthopaedics and can be applied for plasty of fenestrated defects of acetabular roof in hip replacement. Arthrotomy and whirlbone removal are carried out. Whirlbone is transected to form rounded bone lamellae of thickness 3-5 mm. The bone lamellae are jointed in as petals. A graft made hereby is arranged on the defect of acetabular roof so that bone lamellae edges block the defect contour by the value not less lamellae thickness.

EFFECT: method allows increasing prosthesis cup support ability.

1 ex, 3 dwg

Description

The invention relates to orthopedics. It is used to replace (compensate) the acetabular bottom defect, increase the support ability of the pelvic component of the hip joint endoprosthesis during its total endoprosthetics.

During hip joint replacement, the most important element of the operation is the correct and stable installation of the pelvic component, i.e. endoprosthesis cups. This is difficult in cases of protrusion of the bottom of the acetabulum, severe osteoporosis, a traumatic defect, or the consequences of unstable osteosynthesis of fractures of the femoral neck, when the ends of the metal structures perforate the bottom of the cavity.

In order to prevent instability of the endoprosthesis cup and strengthening the bottom of the acetabulum, many orthopedic clinics use expensive support rings to fix the pelvic component.

The essence of the invention lies in the combination of essential features that ensure the achievement of the desired technical result, such as the prevention of instability and dislocation of the endoprosthesis cup into the pelvic cavity during total hip replacement.

The essential features of the invention are that after arthrotomy, removal of the head and neck of the femur, the acetabulum bottom defect is covered with fixed to each other bone plates laid out in the form of “flower petals”, and the edges of the bone plates overlap the defect contour by an amount not less than the thickness of the plates.

The advantages of this method:

- It uses an accessible and uniform plastic material of its own bone tissue that does not cause rejection and allergies.

- Accelerates the integration of the implant into the surrounding tissue.

- Provides closure (compensation) of any size, graduated in the form of a defect in the bottom of the acetabulum.

- Increases the stability and supportability of the cup prosthesis.

The method is illustrated in figures 1, 2 and 3, where the position 1 indicates the dashed line of the osteotomy of the femoral neck 2 - the head of the femur, 3 - fenestrated defect of the bottom of the acetabulum, 4 - acetabulum, 5 - plane of the cross section of the femoral head during bone formation plates, 6 - plastic defect of the bottom of the acetabulum in the form of "flower petals".

The method is as follows

The posterolateral incision reveals the trochanteric region of the femur and the posterior wall of the capsule of the hip joint. Dissect the posterior edge of the joint capsule. Dislocate the femoral head from the acetabulum posteriorly. An osteotomy of the femoral neck is made along line 1 with removal of the head 2.

At the bottom of the acetabulum 5, the dimensions (diameter) of the terminal defect 4 are determined. A femoral head 2 is cut transversely several times in a layerwise manner along the femoral head 2 along planes 5 with the formation of bone plates 3-5 mm thick.

Rounded cutters (necessarily large in diameter of the size of the acetabulum defect) form a bed for the acetabular component of the endoprosthesis. Milling is done to the cancellous bone. After this, the fenestrated defect is covered by bone plates fixed to each other in the form of “flower petals”. The diameter of the graft in the areas of overlapping bone plates should be at least 3-5 mm in diameter of the acetabulum defect. This will prevent its dislocation in the pelvic cavity when installing the endoprosthesis cup, since the graft will bend in the shape of a cavity.

Regardless of the fixation option (cement and cementless), an endoprosthesis cup is installed. Then set the femoral component and the head of the endoprosthesis. Set the head into the cavity. The integrity of the joint capsule is restored and the wound is sutured in layers with the installation of a drainage system. Physiomechanotherapy is subsequently prescribed. Walking is allowed after 2-3 days with a partial load (crutches are used). The term of full load depends on the type of implant installed.

Clinical example

Patient D., 46 years old, with deforming arthrosis of the left hip joint against ankylosing spondylitis, was operated on in December 2005. After arthrotomy and dislocation of the head, an osteotomy of the femoral neck was performed. During the formation of the bed for the endoprosthesis cup with a 46 mm diameter milling cutter, iatrogenic perforation of the acetabulum bottom occurred. A fenestrated bottom defect of 46 mm was formed with an acetabulum diameter of 58 mm. To reduce the risk of instability of the endoprosthesis cup and its displacement into the pelvic cavity, the acetabulum is machined with cutters 56 and 58 mm to the cancellous bone. With a mechanical saw, the femoral head is transversely intersected in layers, with the formation of five rounded bone plates 3-5 mm thick. Bone plates are connected to each other in the form of "flower petals" with catgut sutures, and the diameter of the resulting graft along the overlapping zones was 55 mm. The graft is placed on the defect with a uniform indentation from its edges by 4-5 mm. Next, a cementless endoprosthesis cup with a diameter of 60 mm was installed according to the press fit system. The installation of the endoprosthesis elements was completed, the wound was sutured in layers tightly. The patient is allowed to walk on crutches from the third day. After 30 days, a full load on the operated limb is allowed. At the control examination after 3 months, the patient does not show complaints. On the x-ray of the hip joint, the centering of the endoprosthesis head is correct, the cup of the endoprosthesis is stable.

Claims (1)

A method for plasty of terminal defects of the acetabular bottom during hip replacement, including total replacement of joint elements, the formation of grafts from the cut off femoral head, characterized in that after arthrotomy and removal of the femoral head, the femoral head is intersected with the formation of rounded bone plates with a thickness of 3 -5 mm, connect the bone plates to each other in the form of "flower petals", lay the transplant obtained in this way onto the acetabular bottom defect depressions so that the edges of the bone plates overlap the contour of the defect by an amount not less than the thickness of the plates.

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