RU63210U1 - TOOL FOR BONE PLASTIC SURFACE DEPRESSION (IMPACTOR) - Google Patents

Abstract

A tool for bone grafting of the acetabulum is proposed, consisting of a working part and a handle, the working part being made in the form of a hemisphere with a diameter of 44-58 mm, and the handle attached to the flat surface of the hemisphere, has a cylindrical shape with a rounded top with a length of 5-6 hemisphere diameters and thickness 0.2-0.4 hemisphere diameters. The utility model provides a full filling of the defects of the acetabulum with a bone allograft, which increases the stability of the implanted acetabular component and provides good results in the operated patients. Using the device allows for the full filling of the defects of the acetabulum with bone chips obtained from the heads of cadaverous femurs using a special grinder. It is possible to predict the required volume of a bone graft from preoperative radiographs.

Description

The utility model relates to medicine, in particular to traumatology and orthopedics, and can be used in revision and primary total hip arthroplasty with acetabular defects.

In traumatology and orthopedics, various methods of bone grafting of acetabular defects with the help of an auto- or allograft graft, bone cement, or other osteoinductive and osteoconductive materials are often used.

The use of a bone graft in the form of a truncated distal fragment of the femoral head of a patient is known. This fragment of the head is pressed against the defect from the cavity by the plane of the cross section, after which a bed for the endoprosthesis cup is formed in the cavity and the protruding part of the head with a diameter smaller than the diameter of the acetabulum (RF patent No. 2207075, IPC АВВ 17/56). The disadvantage is that the cut off part of the head may not be suitable for bone grafting due to its pronounced sclerosis during advanced stages of coxarthrosis, in addition, the volume of the graft may not be enough to fill large defects of the acetabulum and its introduction does not fully fill the bone defect. With revision endoprosthetics, the implementation of this technique is impossible.

The objective of the utility model is a tool for bone grafting of the acetabulum during revision hip arthroplasty, as well as during primary total arthroplasty in patients with acetabular defects.

The problem is solved by a device in which the working part is made in the form of a hemisphere (1) with a diameter of 44-58 mm, and the handle (2) attached to the flat surface of the hemisphere has a cylindrical

a shape with a rounded top with a length of 5-6 hemisphere diameters and a thickness of 0.2-0.4 hemisphere diameters.

The tool is made in the following sizes: with a diameter of 44 to 58 mm, in increments of 2 mm, mainly made of steel. Metal handles have a cylindrical shape with a thickening at the end for easy grip by hand.

For acetabular plastic surgery, bone chips are impacted into its defects. Bone grafting is performed as follows. They provide access to the acetabulum according to the described methods and release it from scars and ossifications. With revision endoprosthetics, the acetabular component and bone cement are removed, if cement fixation used to be. Next, the acetabulum is treated with hemispherical acetabular rimers (cones) of increasing diameter to the required size of the proposed acetabular component. Then, the size of the defects of the treated acetabulum is evaluated and, in accordance with this, the required number of bone chips is introduced into the cavity. Then, with the help of an impactor, the diameter of which should be 2 mm smaller than the proposed acetabular component, bone chips are impacted into defects, compacting them as much as possible using the mass of the instrument. After bone grafting, the acetabular component is implanted.

Subsequently, the implanted bone chips act as osteoinductors, and in their place full bone tissue is formed.

Clinical example.

Patient S., 68 years old, medical history No. 44626 was admitted to the 26th trauma unit on October 12, 2006 with complaints of pain in the right hip joint.

Anamnesis: long-term suffering from bilateral coxarthrosis. Operated in 1993 - total endoprosthetics of the right hip joint with the MG prosthesis, in 2005, total endoprosthetics of the left hip joint with the Zimmer hybrid fixation prosthesis. From the beginning of 2005, the patient began to worry about pain in the right hip joint when walking, shortening of the right lower limb. Hospitalized in a planned manner for surgical treatment.

On examination, a relative shortening of the right lower limb is noted - 4 cm, movements in the right hip joint are painful, the patient uses additional support when walking - two crutches. On the presented radiographs - the instability of the femoral and acetabular components of the endoprosthesis of the right hip joint with defects in the posterior wall and roof of the right acetabulum. Endoprosthesis of the left hip joint without signs of instability.

Clinical diagnosis: condition after endoprosthetics of the right hip joint in 1993, of the left hip joint in 2005. Instability of the endoprosthesis of the right hip joint.

After the preparation, the operation was performed on November 01, 2006: Revision endoprosthetics of the right hip joint.

Operation progress: along the old postoperative scar with excision of the latter, the anterior one - the right hip joint is opened in layers by lateral access. After dislocation of the endoprosthesis head, instability of the femoral and acetabular components of the endoprosthesis was found. The femoral component was removed without technical difficulties. Next, the acetabular component is removed. The acetabulum is cleared of bone cement and scars, a significant defect in its posterior wall and roof has been discovered. The acetabulum is processed with cones to the spongy bone under the support anti-protrusion ring of Burch-Schneider 56 size. Next, from the four heads of the lyophilized cadaver femur using

bone chips were obtained on average 0.5 * 0.3 * 0.1 cm in size of a special tool. Next, the chips, soaked in physiological saline, are placed in acetabulum defects and, using the proposed tool, an impactor with a diameter of 54 mm, bone chips are imported into defects, maximally compacting them using the mass of the tool. After that, the acetabulum acquired the correct hemispherical shape. Next, a 56 mm Burch-Schneider anti-protrusion ring was installed and a low-profile Wagner cement-fixed cup was implanted.

The femoral canal was cleaned of cement, and after treatment with rimmers, a revision leg of the Wagner cementless fixation with a diameter of 17 mm and a length of 305 mm was implanted. The prosthesis is set, movements are checked. Lower limbs of equal length. The wound is sutured in layers tightly.

The postoperative period was uneventful, the wound healed first. The patient is activated on crutches. Recommended walking with a dosed load on the right leg for three months after surgery, then full load. In satisfactory condition, the patient was discharged for outpatient treatment on November 11, 2006.

The utility model provides a full filling of the defects of the acetabulum with a bone allograft, which increases the stability of the implanted acetabular component and provides good results in the operated patients.

Using the device allows for the full filling of the defects of the acetabulum with bone chips obtained from the heads of cadaverous femurs using a special grinder. It is possible to predict the required volume of a bone graft from preoperative radiographs.

Claims (1)

The instrument for bone grafting of the acetabulum, consisting of a working part and a handle, the working part being made in the form of a hemisphere with a diameter of 44-58 mm, and the handle attached to a flat surface of the hemisphere, has a cylindrical shape with a rounded top 5-6 hemisphere diameters and a thickness of 0 , 2-0.4 hemisphere diameters.