RU2358680C1 - Blocked rod for long bone fracture treatment - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, particularly to orthopaedics and traumatology. A blocked rod represents a metal pin with 2 blocking screw holes in a proximal part, a guide join thread at an end face of the proximal part. The distal part of the rod is coated with hydroxyapatite film.

EFFECT: invention ensures reduced number of distal incisions and injuries of soft tissues and bone, lower infection risk, reduced injuries of endosteum and internal cortical plate, reduced operation length.

1 dwg, 1 tbl

Description

The invention relates to medicine, in particular to orthopedics and traumatology, and is intended for the treatment of diaphyseal fractures of long bones.

Rods for treating diaphyseal fractures of long bones with the help of submersible intramedullary structures such as the rod of Bogdanov et al. [Traumatology and orthopedics: A textbook for students of higher educational institutions // Kavalersky G.M., Silin L.L., Garkavi A.V. and etc.; Edited by G. Kavalersky - M.: Publishing Center "Academy". - 2005. - S.90-91].

Significant disadvantages of this rod are:

- invasiveness and invasiveness of the intervention when installing the rod; - the need for an open reposition of the fracture with subsequent osteosynthesis by the rod.

- the risk of infectious complications;

- the probability of migration of metal, because the latter is not fixed in the bone.

The closest to the lockable rod we offer for the treatment of diaphyseal fractures of long bones is an intramedullary pin with blocking [Traumatology and orthopedics: A textbook for students of higher educational institutions // Kavalersky G.M., Silin L.L., Garkavi A.V. and etc.; Ed. Kavalersky G.M. - M.: Publishing Center "Academy". - 2005. - P.91; Suvalyan M.A. // Bulletin of Traumatology and Orthopedics. N.N. Priorova. - 2002. - No. 1. - S.40-43]. The rod is a pin that is locked in the bone by two screws in the proximal part and two screws in the distal part by means of a guide attached to the proximal part of the pin. The pin has corresponding holes for screws and threads for attaching a guide at the distal end. However, the disadvantages of this method are:

- injuries - the need for surgical intervention with a minimum of three cuts (for insertion of the pin, for proximal and distal blocking of the pin);

- the risk of developing infectious complications due to the need to make at least three cuts;

- difficulties with distal blocking, even in the presence of an image intensifier tube, since during the operation inevitably there is a violation of the desired ratio between the axis of the limb and the guide.

We first proposed the design of the rod for the treatment of diaphyseal fractures of long bones, which is a pin only with proximal locking with screws, which is carried out thanks to two holes in the proximal part of the pin. At the end of the proximal part of the rod there is an internal thread for attaching a guide. The pin is coated in the distal part with a biologically active osseointegration coating deposited by plasma spraying.

A thin biologically active layer 200 microns thick with a certain porous structure, surface morphology, and adhesive-cohesive properties is formed on the surface of such an implant. When such implants are introduced into the bone tissue, the bone grows efficiently into the pores of the coating, or rather, the healing process integrates a porous powder thin coating, for example, hydroxyapatite ceramic or other composition on a compact basis, with living tissue. This provides a durable and long-term fixation of the implant and its normal functioning in the body. Titanium powder is applied to the titanium base of the implant using plasma spraying technology, and then a coating of biologically active ceramics is applied. Due to the distribution of ceramics over the porous structure of the metal, strong fusion with the bone tissue of the recipient is achieved, as well as chemical and physiological stability, which allows us to consider this system as ideal for intraosseous implantation. [Modern problems of implantology: abstracts of the 4th international conference May 25-27, 1998 - Saratov 1998. // Sukachev V.A. Operations in dentistry. M., "Knowledge" // Intraosseous dental implant. Designs, technologies, production and application in clinical practice. / V.N. Lyasnikov, L.A. Vereshchagin and others / under the editorship of V.N. Lyasnikova, A.V. Lepilina - Saratov. Publishing House of Saratov University 1997 // New concepts in technology, production and use of implants in dentistry: abstracts of international conferences June 15-18, 1993 - Saratov 1993.]

The proposed rod is shown in the drawing, where 1 is a metal pin, 2 is a hydroxyapatite coating in its distal part, 3 are holes for locking screws in the proximal part, 4 is a thread for attaching a guide.

Our proposed lockable rod for treating diaphyseal fractures of long bones is used as follows: for osteosynthesis, a lockable intramedullary pin was used, coated in the distal part with hydroxyapatite by plasma spraying, in the proximal part with two holes for locking with screws and tools for their introduction. The length of the pin was selected by measuring the segment of interest on a healthy limb.

In the operating room, the patient was laid on the operating table. Then, following the rules of aseptic-antiseptic, under general anesthesia, a skin incision was made in the projection of the proximal bone metaphysis. Muscles were bred along the fibers. A guide drill was inserted into the medullary canal in the proximal part of the bone. Using a cannulated drill, a medullary canal was opened through a guide drill. Then a pin was inserted, the distal part of which was coated with a hydroxyapatite osseointegration coating with a guide device for proximal blocking fixed to it, to the fracture site, the fragments were repositioned, and the pin was inserted into the medullary canal of the distal fragment. When osteosynthesis was achieved, proximal locking of the pin was performed. X-ray control. The wounds were sutured in layers. Aseptic dressings were applied to postoperative wounds.

The average duration of surgery was 60 minutes, in contrast to surgical treatment with a pin with proximal and distal screw locking, which lasts about 80 minutes. Due to minor blood loss, transfusion of blood components was not performed.

Under our supervision, there were 24 patients aged 18 to 65 years with fractures of long bones of the extremities. The distribution of nosologies is presented in table 1. Depending on the type of treatment, we identified two groups of patients.

Table 1 Diagnosis Number of patients I group II group Femur diaphysis fracture in s / 3 5 four Fracture of the tibia diaphysis in n / 3 four four Fracture of the shoulder in n / 3 3 four Number of patients 12 12

Group I patients received treatment according to our proposed method. II group of patients was treated according to a known method [Suvalyan M.A. // Bulletin of Traumatology and Orthopedics. N.N. Priorova. - 2002. - No. 1. - S.40-43].

In the course of treatment, we monitored the clinical and radiological pictures. The terms of fracture fusion in the I and II group of patients were approximately the same.

No complications were observed during treatment; a good anatomical and functional result of treatment was obtained.

The advantages of the proposed device - a rod with a hydroxyapatite osteointegration coating, applied by plasma spraying, for conducting closed osteosynthesis of fractures of long bones - are that

- the number of incisions and traumatization of soft tissues and bones in the distal section is reduced,

- the risk of infection is reduced,

- no additional reaming of the medullary canal traumatic endostomy, the internal cortical plate,

- reduces the time of surgical intervention due to the fact that there is no distal locking of the pin.

Claims (1)

A lockable rod for treating fractures of long bones, which is a metal pin with 2 holes for locking screws in the proximal part, a thread for attaching a guide at the end of the proximal part, characterized in that a hydroxyapatite coating is applied to its distal part.