RU2542510C1 - Method for preparing bone-cement spacer - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: what is described is a method for preparing a bone-cement spacer with an antibiotic consisting in the fact that a spacer surface is coated with coarse-grain salt immersing them completely into the a setting bone-cement layer; after the bone cement has set completely, the spacer is submerged.

EFFECT: more effective delivery of the antibiotic by enlarging the surface area of the cement spacer.

Description

One of the main reasons for the decrease in the survival rate of hip arthroplasty is the development of a deep periendoprosthetic infection [Akhtyamov, I.F. Errors and Complications of Hip Replacement: A Guide for Physicians. / Akhtyamov I.F., Kuzmin I.I. // Kazan: center of operational printing, 2006. - 328 p.]. The incidence of such complications in primary endoprosthetics ranges from 0.8% to 2.4%. Revision interventions increase the risk of purulent complications 2-5 times [Magnan, B. Antibiotic-loaded cement spacer for two-stage revision of infected total hip replacements / Magnan B .; Regis D .; Corallo F. // Orthopedic Department, University of Verona, Italy. Bone and Joint Surgery - British Volume, Vol. 87-B, Issue SUPP.II, 188, 2005]. A modern method of treating a developed deep periendoprosthetic infection is the removal of all components of the endoprosthesis and the infected cement mantle, the rehabilitation of the bone structures of the acetabulum, the proximal femur and the installation of a temporary therapeutic endoprosthesis (spacer) [Garcia, S. The use of articulated spacer hip for the treatment of total hip arthroplasty infection / Garcia S., Soriano A., Font LI, Bori G., Gallart X., Tomas X., Fuster D., Riba J., Mensa J. // Bone and Joint Infection Unit. Hospital Clinic of Barcelona. - 2007 EBJIS Corfu].

Various types of spacers are known: prefabricated, or preformed, and intraoperatively made from bone cement with the addition of antibiotics - cast in molds or made according to the Hoffman method [Romano, C. Strategy and results of two-stage treatment of infected THA / Romano C, Meani E. // AAOS - March 2006 - Chicago, USA]. The therapeutic effect of the spacers is based on the high content of antibiotics, which are released locally for a long (3 to 6 months) time, sufficient to suppress the infection process in the underlying bone tissue, as well as the preservation of articulating functions.

The disadvantages of preformed spacers are the limited antibacterial effect due to the use by manufacturers of a narrow circle of antibacterial substances (gentamicin, tobramycin). When verifying the causative agent of a para-prosthetic infection with a lack of sensitivity to the above antibiotics, in order to enhance the antibacterial effect, bone cement containing antibiotics is introduced mechanically into the spacers, taking into account the sensitivity of the microflora, however, it is not possible to achieve the necessary therapeutic antibiotic concentration in this way.

The use of a cement spacer made during the operation allows achieving the necessary antibacterial effect, however, such spacers have a limited surface area, which reduces the amount of antibiotic released into the surrounding tissue.

The essence of the invention lies in the combination of essential features ensuring the achievement of the desired technical result, such as increasing the efficiency of the return of the contained antibiotic by increasing the surface area of the cement spacer.

The essential features of the invention are that the spacer is made of bone cement with an antibiotic, and at the final stage of polymerization, large granules of sodium chloride are applied to the spacer surface, completely immersing them in a layer of solidifying bone cement, and after complete solidification, the spacer is immersed in water.

The advantages of this method are:

- manufacture of a spacer according to individual patient sizes,

- due to the dissolved crystals of sodium chloride, the surface area of the spacer increases many times, which ensures a large return of the antibiotic to the surrounding tissue,

- the use of table salt is safe for the patient’s body,

- each of the components of the spacer is easily sterilized (bone cement, antibiotic and salt),

- an increase in the surface of the proposed method is possible with any shape and size of the spacer.

The proposed method is as follows.

During the operation, the necessary size and shape of the space filled by the spacer is determined. Subject to the sterility conditions, an appropriate amount of the selected antibiotic is added to the liquid or powder component of the bone cement. Mix both parts of the bone cement, give the appropriate shape and size to the spacer. Large granules of sodium chloride are applied to the surface of the spacer, completely immersing them in a layer of solidifying bone cement. After solidification, during a period of increasing bone cement temperature, the spacer is immersed in a sterile solution (water, saline, etc.). Salt granules dissolve, and crater-shaped cavities form on the surface of the spacer. Thus, table salt is completely dissolved, and bone cement cools to the temperature of the surrounding solution. Then the spacer is installed in the planned area of the patient’s tissue.

Clinical example

Patient G., aged 57, was admitted to the clinic in October 2012 with a diagnosis of deep periprosthetic infection of the hip joint. Arthrotomy was performed under regional anesthesia and the acetabular element of the hip joint prosthesis was removed. The endoprosthesis leg is kept in place. It was decided to manufacture a spacer of a spherical shape to fill the acetabulum. A spherical spacer is made of bone cement with an antibiotic in a volume of 40 g according to the above method. The size of the ball was fully consistent with the size of the acetabulum of the patient after removing the cup of the endoprosthesis. In the process of solidification over the entire surface, large crystals of sterilized sodium chloride were immersed in bone cement. After solidification of bone cement and at the beginning of heating, the spacer is completely immersed in sterile physiological saline (0.9% NaCl solution). After 5-7 minutes, the crystals of sodium chloride dissolved and the spacer was removed from the solution. The entire surface of the spacer was covered with crater-shaped depressions. After thorough mechanical and drug treatment of the surrounding tissues, the spacer is laid in the acetabulum. The wound is sutured tightly. The drainage tube is installed through a contra-hole. The patient is recommended walking with a partial load on the operated limb. The infectious process was stopped, the wound healed by primary intention. Four months later, the spacer was removed and a permanent pelvic component of the endoprosthesis was installed. Recurrence of infection with further observation was not detected.

Claims (1)

A method of manufacturing a bone cement spacer, including the manufacture of a bone cement spacer with an antibiotic, characterized in that large granules of table salt are applied to the spacer surface by immersing them in a layer of solidifying bone cement, and after the bone cement has completely solidified, the spacer is immersed in water.