RU2624674C1 - Method for intramedular knee joint arthrodesization using extending pin - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: extending pin with an oval hole is used which is connected to the femoral pin forming a single metal structure. The metal structure is inserted into the pre-grooved bone marrow canal of the femur to the distal metaepiphysis of the femur, using an impactor-extractor under the electron-optical transducer control, it is punched through the distal metaepiphysis of the femur, through the knee joint, through the proximal metaepiphysis of the tibia, and passing through the upper third of the medullary tibial canal before entering the tibia istus, the proximal dynamic blocking is performed by a screw through the oval hole of the proximal part of the metal structure.

EFFECT: method allows to reduce trauma, prevent limb shortening.

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Description

The invention relates to medicine, namely to traumatology and orthopedics. The invention provides the creation of a complete intramedullary arthrodesis of the knee joint, in particular in patients with age-related changes in bone tissue (deforming arthrosis), as well as a method of choice in patients with complicated consequences after endoprosthetics, with minimal damage to bone tissue and soft tissue component of the lower limb when performing surgical access .

An analogue of the extension pin is the intramedullary femur pin for intramedullary hip osteosynthesis [Traumatology and Orthopedics: Textbook for students of higher educational institutions // Kavalersky G.M., Silin L.L., Garkavi A.V. et al. Ed. Kavalersky G.M. - M: Publishing Center "Academy", 2005. S. 91; Suvalyan M.A. Bulletin of Traumatology and Orthopedics. N.N. Priorov. - 2002. - No. 1. - S. 40-43], which differs from the extension pin in that it is cannulated, has round through holes for static blocking at the proximal and distal ends, in cross section has a butterfly pattern, in the middle third of its length has a bend under the anatomical bend of the femur . The distal end ends with a somewhat pointed end. The similarities are as follows: there is a through oval hole for dynamic blocking, a smooth transition of the proximal part to the distal portion of a smaller cross-sectional area, from the end side there is a coaxial hole for the target’s shoulder. The femoral pin itself is part of the kit for performing intramedullary arthrodesis of the knee.

The femoral pin has the following disadvantages, such as: a fracture of the metal structure itself may occur, it is possible to deform the thread of the proximal end when piercing the metaepiphysis of the femur and its isthmus, which can lead to slight instability of the metal structure as a whole. It is also a potential foreign body and can, like other metal implants known in traumatology, lead to the formation of aseptic inflammation and further rejection, as well as the migration of the entire metal structure.

Known methods of arthrodesis of the knee joint, where external fixation devices are used: compression-distraction, rod apparatus of the Ilizarov type (SU 538710, publ. 12/15/1976), rod compression and distraction apparatus of the ICC (according to OA Malakhov, OV Kozhevnikov , V.E. Tsukanov), (RU 2063720, publ. 07.20.1996). An open method allows access to the modified knee joint - resection of the residual articular surfaces is performed, the wound is sutured. The MCC apparatus is simulated for two limb segments based on the length of the thigh and lower leg. Then three threaded rods are screwed into each segment, which are attached to the device.

This method is not socially adapted and the process of arthrodesis in external fixation devices does not allow the patient to move independently, as the device restricts movement and can lead to injuries to a healthy limb by elements of the device, such as the protruding part of the Shants rod, fixing bolts, Kirschner spokes. Also, in the venues of the rods and knitting needles, local suppuration of soft tissues is always formed, which often progresses up to the so-called "spoke" osteomyelitis and the formation of phlegmon and pressure sores, which is an indication for dismantling the device with arthrodesis that has not yet taken place and the subsequent formation of the false joint.

There is a method of arthrodesis of the knee joint, which consists in making an arcuate incision from the inner epicondyle of the thigh to the outer through the tibial tuberosity region, dissecting the transverse ligament of the patella, joint capsule, soft tissue along the lateral surfaces of the joint, pulling the tongue-like flap upwards with a sharp hook, including . The lateral and cruciate ligaments of the joint are dissected with a scalpel and scissors, gradually bending the lower leg, then the synovial membrane, cruciate ligaments, menisci, fat pad, and the joint ends of the femur and tibia and the articular surface of the patella are excised. Then, with a straight chisel on the upper surface of the tibia near the front edge, a notch is made into which the lower pointed edge of the patella, freed from cartilage, is inserted. The back surface it is pressed to the femur, also freed from cartilage. The operation is completed by stitching the wound. Postoperative limb immobilization can be twofold: by applying a hip plaster cast with a window in the wound area or one of the compression devices. (Operational orthopedics / Ed. By Professor Movshovich I.A. M .: Medicine, 1994. S. 308.)

The disadvantage of this method is the shortening of the limb, the high invasiveness of the soft tissue component and, as a result, a number of complications are possible.

As a prototype, a method of blocked intramedullary hip osteosynthesis using femoral pins (Krettek C. Prinzipienderintramedullaren Knochenbruchstabilisierang. Teil 2: Operationstechnik // Unfallchirurg 104 (2001): 748-771) was selected. The main stages of which are preoperative planning (selection of the type and size of the implant), placement of the patient, opening of the bone marrow canal, reposition of the fracture, reaming of the bone marrow canal, insertion of the pin until the distal metaepiphysis of the femur without piercing it, and then blocking in the distal and proximal parts of the pin, using a standard set of tools to perform this kind of operation

The disadvantage of the prototype is that this method is indicated in the treatment of diaphyseal hip fractures. For knee arthrodesis, this method has been modernized.

The objective of the present invention is to provide a complete intramedullary arthrodesis of the knee joint, in particular in patients with age-related changes in bone tissue (deforming arthrosis), as well as a method of choice in patients with complicated consequences after endoprosthetics with a final increase in the effectiveness of treatment and social adaptation.

The scientific novelty of the invention lies in the fact that for the first time a method of intramedullary arthrodesis of the knee joint based on an original set of metal structures is proposed.

The technical result consists in eliminating shortening of the limb, achieving strong fixation of the knee joint without impaired blood circulation, and facilitating patient care. Improving social adaptation and quality of life in the postoperative period.

The specified technical result is achieved by the fact that the method of intramedullary arthrodesis of the knee joint using the femoral pin with the main stages of preoperative planning includes selecting the type and size of the femoral pin, laying the patient, opening the medullary canal, reposition of the fracture, reaming of the medullary canal, while additionally using an extension pin with an oval hole, which is connected to the femoral pin, forming with it a single metal structure, which they injected into the pre-drilled bone marrow canal of the femur to the distal metaepiphysis of the femur, and using an impactor-extractor under the control of the electron-optical transducer, pierce through the distal metaepiphysis of the femur, through the cavity of the knee joint, through the proximal metaepiphysis of the tibia and pass through the bone marrow canal of the tibia before proximal to the tibia isthmus zone, proximal dynamic screw blocking is performed through the oval hole of the proximal part of the metal structure.

The present invention is illustrated by drawings, in which:

FIG. 1 is a general view of an extension pin,

FIG. 2 is a drawing of an extension pin,

FIG. 3 is a general view of the assembled metal structure (extension pin and femoral pin),

FIG. 4 - assembled metalwork with a targeting arm,

FIG. 5 - the optimal point of introduction of metal structures,

FIG. 6 - General view of the metal structure after piercing in the medullary canal,

FIG. 7 - blocking metal in the medullary canal,

FIG. 8 - five points of fixation of metal in the medullary canal

The present invention is presented in the form of an extension pin 5 for performing intramedullary arthrodesis of the knee joint, characterized by an all-metal extended body in the form of a tapering cylinder with a round cross section, a smooth transition of the proximal part to the distal portion of a smaller cross-sectional area, while there is a coaxial opening 3 under the connecting side for connecting screw 7 of the shoulder of the target 6 and one through hole 2 of an oval shape for a locking screw 11 located in the perpendicular oskosti pin symmetry, the distal end has a thread 1, a coaxial connecting opening 3 to the shoulder screw 6 7 Target.

The extension pin when twisting by means of its thread 1 at the distal end with an opening 8 under the shoulder of the targeting device 6 of the femoral pin 4 for intramedullary osteosynthesis allows you to create a single metal structure (see Fig. 3), designed for intramedullary arthrodesis of the knee joint due to the elongation effect, while achieving the optimal length allowing this manipulation to be carried out with fixing a single structure at five points of the anatomy of the lower limb (see Fig. 8). Due to the all-metal structure of the extension pin 5, axial stability of the entire metal structure is achieved. Due to the smooth transition of the proximal part of the femoral pin 4 of a larger cross-sectional diameter to a smaller part, a wedging effect is achieved in the isthmus 12 (the narrowest part) of the thigh. The presence of an oval hole 2, designed to perform dynamic blocking, allows you to further enhance the rotational stability of the entire metal structure with an element of dynamic load on the arthrodesis zone (knee joint) to accelerate adhesion.

To perform intramedullary arthrodesis, a set of metal structures is required, consisting of an all-metal extension pin 5 (see Fig. 1, 2) with a threaded coaxial hole 3 for the connecting screw 7 of the target arm 6, an oval hole 2 for dynamic blocking and an end thread 1 for coupling (twisting ) with a lockable femoral pin 4 used for hip osteosynthesis. The assembly of the final metal structure consists in twisting the extension pin 5 with the femoral pin 4 together by means of the thread 1 of the extension pin 5 and the standard hole 8 for the connecting screw 7 of the targeting arm 6 in the femoral pin 4, thereby obtaining a single structure shown in FIG. 3. By connecting the shoulder of the target 6 by screwing into the threaded coaxial hole 3 of the connecting screw 7 of the shoulder of the target 6, access is formed through the skin along the diaphysis of the femur proximal to the apex of the greater trochanter. The gluteus maximus muscle is diluted along its fibers. The interval between the attachments of the piriformis tendon and the posterior part of the tendon of the gluteus maximus muscle to the greater trochanter is determined. Regardless of the position of the patient on the table, the point of introduction of the design should be a pear-shaped fossa that coincides with the axis of the medullary canal (see Fig. 5). From here, an awl is introduced under the control of the electron-optical converter to open the bone marrow canal of the femur. This point is located on the very medial edge of the apex of the greater trochanter and behind the central axis of the femoral neck, in the pear-shaped fossa. Next, a flexible conductor is inserted into the opened medullary canal to drill the medullary canal using a set of scans for conducting the structure through the isthmus 12 of the thigh.

The opened metal structure is inserted into the opened and recessed bone marrow canal of the femur until it stops (until the distal metaepiphysis of the femur 13. Next, the impactor-extractor is screwed under the punch onto the target’s shoulder 6, and the metal structure penetrates under the control of the electron-optical transducer through the distal metaepiphysis of the femur 13, through the cavity of the knee joint, also breaks through the articular surface of the proximal metaepiphysis of the tibia 14 in the bone marrow tibial fissure up to wedging (persistent stop) in the isthmus of the tibia 15 when the knee joint is bent no more than 10 degrees (see Fig. 6) .In this case, the place of violation of the integrity of the skin remains only an access point for the introduction of metal in the upper third of the thigh. Thus, figure 6 shows a general view of the metal structure in the medullary canal and two points of control of the achieved driving depth: the border of the upper and middle third of the thigh 9 and lower leg 10. The impactor-extractor is twisted from the target’s shoulder 6, the target is screwed up if necessary and suspected of rotational instability of the metal structure in the channel and proximal dynamic blocking of the extension pin 5 is carried out with screw 11 through the target (see FIG. 7). In the hole for blocking the target, a protector guide is inserted into the trocar for the passage of soft tissues to the bone. The trocar is removed and the drill guide is inserted. A drill with a drill drills a hole through two cortical layers of the femur, through the oval hole 2 of the extension pin 5 located inside the medullary canal (see Fig. 7). Based on the markings on the drill, the required screw length is determined. The drill guide is removed. The locking screw 11 is screwed in. The tread guide is removed. Next, the connecting screw 7 is unscrewed from the metal structure, the targeting arm (6) is removed.

Thanks to the original metal construction with an extension pin having an all-metal extended body in the form of a tapering cylinder with a circular cross-section, a smooth transition of the proximal part to the distal portion of a smaller cross-sectional area, there is a threaded coaxial hole 3 from the end side for the connecting screw 7 of the targeting arm 6 and one a through hole 2 of an oval shape for a blocking screw 11 located in the perpendicular plane of symmetry of the pin with the aim of dynamic blocking in the case of e insufficient rotational stability of the overall steel. This design makes it possible to perform intramedullary arthrodesis of the knee joint with final fixation at 5 points of the lower extremity: proximal blocking by holding the locking screw 11 through the oval hole 2 in the extension pin (see Fig. 1), the wedge point of the proximal part of the femoral pin in the isthmus 12 of the thigh , metaepiphyses of the femur and tibia 13, 14 with a final stop in the isthmus of the tibia 15 (see Fig. 8).

Based on the developed invention and method, 2 operations were performed.

Claims (1)

The method of intramedullary arthrodesis of the knee joint using a femoral pin, with the main stages of preoperative planning, including selecting the type and size of the femoral pin, laying the patient, opening the medullary canal, reposition of the fracture, reaming of the medullary canal, characterized in that the extension pin is additionally used with oval hole, which is connected to the femoral pin, forming with it a single metal structure, which is introduced into the pre-drill the bone marrow canal of the femur to the distal metaepiphysis of the femur, and using an impactor-extractor under the control of the electron-optical transducer, they pierce through the distal metaepiphysis of the femur, through the cavity of the knee joint, through the proximal metaepiphysis of the tibia and, passing through the upper third of the tibia before wedging into the tibia isthmus zone, proximal dynamic screw blocking is performed through the oval hole of the proximal hydrochloric metal part.

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