KR20130111675A - Dilatation of the medullary cavity for intramedullary pin fixation of metacarpal/metatarsal bone or phalangeal bone fractures - Google Patents

Abstract

The present invention relates to a surgical treatment associated with anterior / hind limb bone and phalanx fractures occurring in veterinary orthopedic surgery, and it is difficult to repair with an internal fixation or an external skeletal fixator using a plate & screw system, which is difficult to apply in small dogs. This is a technique you can use. The small diameter of long bones of small breed dogs is too large for general internal fixation and external fixation techniques, so it may be replaced by conservative treatment rather than surgical fixation, but the prognosis is difficult to predict and results are not good. many. Accordingly, the present invention is to devise a method for stabilizing fractures by applying intraocular nails, even if there is a limitation of the diameter of the fractured bone, the purpose of maximizing anatomical alignment and functional recovery.
In the present invention, the method of solving the above problem is small K-wire by expanding the bone marrow when the bone marrow is small and the diameter of the whole cross section is small, or by cutting a portion of the cortical bone together with the expansion of the bone marrow into the expansion range. The key is to secure space for insertion. The K-wire, which was installed in this way, resists bending and torsional forces in terms of the biomechanical force of the fracture through friction between the medial side of the enlarged bone fragment and the implant. Sufficient holding force can be exerted. This method can be applied to many small-sized dogs as a method that can be treated with surgically stable fixation in a special fracture in which surgical treatment is difficult and conservative treatment is poor.

Description

Dilatation of the medullary cavity for intramedullary pin fixation of metacarpal / metatarsal bone or phalangeal bone fractures}

The present invention is to perform a fixation using an intramedullary pin in bone fractures of very small bone marrow lumen, including metacarpal / metatarsal bone of small dogs in veterinary orthopedic surgery. The procedure relates to the expansion of the bone marrow cavity (medullary cavity).

Fracture of the anterior / hind limb is associated with the third and fourth metacarsal or metatarsal III and IV where the fracture site is responsible for weight-bearing when more than one fracture occurs in one leg. In the case of intra-articular fracture, surgical correction is recommended in cases where the fragment fragment displacement is 50% or more. Surgical fixation using a bone plate is known to be radiologically compatible with the anatomical alignment of the fracture site in large, non-small dogs, but no studies have demonstrated that one treatment is superior to others. The incidence of complications was high in both surgical and conservative treatments. Especially in small dogs, the diameter of the affected bone is small, so that fixation using plates and screws is almost impossible, and external skeletal fixation is not easy. Surgical correction that can be chosen in this situation is fixation using an intramedullary Kirschner wire. This procedure is also not easy due to the diameter of the bone marrow lumen of small dogs. Therefore, the present invention has been devised a method for performing internal fixation by securing a space for inserting a small diameter K-wire through bone marrow expansion, and introduces such a bone marrow expansion.

US 6,168,599 B1 US 4,473,070

Improving surgical reduction in radial fractures using a dowel pinning technique in miniature and toy breed dogs. Yu J, DeCamp CE, Rooks R. Vet Comp Orthop Traumatol 2011; 24: 45-49.

In the present invention, conservative treatment is difficult in fractures of bones with a small diameter and small bone marrow, such as forefoot or hind bone of dogs and cats, and when surgical correction is necessary, fixation and external fixation using bone plates and screws Skeletal fixation is often difficult to use clinically due to the limitation of implant size. In this case, the fixation method using an internally fixed pin is considered, but it is also difficult to apply internally in small-sized dogs due to the limitation of the medullary diameter and the diameter of the Kirschner wire. Therefore, the present invention devised a technique for inducing stabilization of fractures by devising a technique for expanding intramedullary canal for intraocular lens application in bone fractures with the diameter of bone marrow lumen, which is difficult to install. have.

In order to solve the above problems, in the present invention, fractured long bones are exposed using an appropriate preoperative approach. Position the exposed fracture section perpendicular to the operator's field of vision and expand it in the center of the bone marrow using an orthopedic drill equipped with a drill bit corresponding to the diameter of the K-wire to be applied. reaming). The opposite bone fragment then expands the bone marrow in the same way. In this case, it is common to apply the diameter of K-wire smaller than the diameter of the original bone marrow (when using a single crystal alone, use a pin corresponding to at least 70% of the diameter of the bone marrow) or the indication of the present invention. Since is no K-wire smaller than the diameter of the bone marrow, the implant with the smallest diameter among the K-wires smaller than the outer diameter of the fractured bone is selected. And inserting an intraocular lens into the enlarged bone marrow cavity. Insertion of the intraocular lens is performed in the same manner as the technique called the dowel pinning technique. In detail, the K-wire prepared in the longer one of the fractured fragments is retrograde inserted. After this, the K-wire is cut to the length of the remaining bone fragments and the distal fragment is pulled to the extent that the K-wire can be inserted in the distal direction. After contacting the bone marrow cavity, the direction is adjusted so that the K-wire and the distal bone piece are in a straight line, and the traction force is gradually released to complete the reduction and fixation of the bone piece.

The present invention is a novel surgical technique that can be used to perform intramedullary pin fixation that can exert adequate fixation force in iliac fractures with very small bone diameters. These bones cannot be fixed in the bone marrow using normal size Steinmann pins or Kirschner wires (K-wires), and internal fixation using plate & screw systems is also almost impossible due to implant size limitations. However, when the bone marrow augmentation proposed by the present invention is performed, it is effective to allow surgical reduction and fixation of the fracture of the long iliac bone, which is difficult to correct surgically, rather than conservative treatment. Complications can be prevented. In addition, there may be rotational instability in the diaphyseal fracture of the iliac bone alone. However, in this procedure, the inner surface of the extended intramedullary cavity is in contact with the inner surface of the intramedullary canal for frictional force. Formation results in resistance to torsional forces. This can maximize the effect of the single fixing method by maintaining the resistance to bending force which is the main advantage of the internal well, and overcomes the rotational instability which is the major disadvantage of the internal well.

1 is a schematic view of the cross-section showing the procedure of the present invention sequentially.
The left picture shows the fractured section of the bone fragment and the original bone marrow cavity. The figure in the center shows the expansion of the bone marrow cavity using a drill bit. The figure on the right shows the bone fragment after expanding the bone marrow cavity.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Radiographs of the fractured patients at the site confirm the outer diameter and bone marrow diameter of the fractured bone, and determine the length of the K-wire to be inserted by measuring the length of the bone. K-wires shall be prepared with the smallest applicable diameter and the diameter shall not exceed the outer diameter of the bone. When the size of the K-wire is completed, prepare drill bits with the same diameter as the prepared K-wire. The anesthetized patient is placed in a post-accessible posture, aseptically prepared and the fractured bone is exposed using a standard approach. During bone reduction and fixation, bone holding forceps can be used to manipulate the bone fragments, but gripping the bone fragments with the operator's hand may be easier to handle when the bone fragments are very small. have. Using the operator's non-dominant hand, the longitudinal axis of the bone coincides with the operator's visual axis, and with the dominant hand, the orthopedic drill is operated to expand the bone marrow lumen. . In the same way, the bone marrow of the opposite bone piece is expanded.

After complete bone marrow dilatation of both bone fragments, intraocular lens implantation should be performed from the longer bone fragment. The intraocular lens is inserted retrograde to the end of the dilatation section, and the pinnacles are cut using the pin cutter to fit the length of the short fragment. After cutting, the proximal fragments are fixed in place and the distal fragments are pulled in the distal direction after gripping the opposing bone fragments and the opposing bone fragments respectively with both hands. Towing until the abutment of the cut intramedullary nail and the bone marrow opening of the opposite bone piece is brought into contact with each other, and then gradually inserted into the opposite bone piece to anatomically reduce the bone fragment.

1: small diameter, long bone with little medullary cavity
2: medullary cavity
3: dilated medullary cavity
4: drill bit
5: chuck

Claims (1)

Intramedullary Nailing for Intraocular Fixation in Fine Diameter Iliac Fractures of Small Animals
(a) Expansion of the bone marrow in the distal and proximal bone fragments in the fracture of the long iliac bone.
(b) If the entire bone diameter is very small, the procedure is to secure a K-wire insertion space by reaming part of the cortical bone.
(c) Procedure to fix the fracture by using an intraocular nail after completion of expansion.

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