TECHNICAL FIELD

The invention is related to a new locking mechanism allowing the distal locking screw in intramedullary nails used for orthopedic and traumatological long bone fracture detection to be applied without using a scoping device and independently of the patient's position.

PREVIOUS TECHNIQUE

Femoral shaft fractures are the most common pathology of the lower extremity traumas. The rapid progress of industrialization has increased traffic and job accidents, which has increased the frequency of femoral shaft fractures. The most important factor in increasing the incidence of the disease is that the femoral shaft fractures are usually caused by high-energy trauma. Various treatments have been published in the literature in femoral shaft fractures. The locked intramedullary nailing method is suitable for the anatomical and biomechanical structure of the femur bone; with high conglutination and low complication rates, is an outstanding treatment modality for adult femur shaft fractures.

The purpose of the treatment of femoral shaft fractures is to provide the anatomical integrity of the extremity and to provide the patient with early-stage functions. There are many treatment modalities for this purpose. Complications related to long-term immobilization seen in conservative treatment and treatment-related complications such as angular and rotational deformities, shortness, joint stiffness and atrophy of the chest have now standardized surgical treatment.

The popularity of intramedullary nails in the treatment of femoral shaft fractures is increasing. Intramedullary spaying is the gold standard in the treatment of femoral shaft fractures because of good stabilization, early loading and joint motion, less soft tissue gap, less angular and rotational deformity, and higher fracture union.

Intramedullary nails commonly used today are;

1 - Standard intramedullary nails: Nails like Kuntcsher, AO, Schnider, Samson. They are based on the principle of stability restoration with endosteal contact from multiple points by filling channels throughout the length of the bone. Indications are isthmic fractures.

2- Flexible intramedullary nails: Rush and Ender nails are in this category. Ender nail is the most commonly used in adult femoral shaft fractures. It is based on the three-point principle. It's used without bone conduction.

3- Clinical intramedullary nails: They are obtained by adding proximal and/or distal locking screws to the intramedullary nail. Locking screws are sent from the lateral cortex to the medial cortex. There are basically two methods of fracture detection.

a. Static locking

b. Dynamic locking

We can list the disadvantages of closed reduction and intramedullary nailing as follows;

• Fracture reduction and rotational control are more difficult.

• Requires a richer hardware and a more experienced team (broken table, scopy device).

• The surgeon, assistant healthcare personnel and the patient have increased exposure to radiation from more scopy use.

These type of nails is the group with the highest stability. Conglutination rate is high, misalignment and dis-conglutination rates are low. However, it is technically very difficult to apply the distal locking screws which increase the stability. The reason for this is the metal flex of the intramedullary nail in the medulla. For this reason, externally used guides can not catch holes in the distal portion where the screws will sit on. Surgeons generally agree that the most difficult part of the femoral locked nailing is the placement of the distal screw.

In summary, fractures of long bones such as femur and tibia are the most common problems that orthopedics and traumatology have to this date. Kuntscher described the intramedullary fixation method while the fixation methods with plate screws were the initially used in the treatment. In this method, fracture detection is defined with the help of a longitudinal gap in the middle of long bones. With the advancing technology and surgical techniques, it has become possible to lock the intramedullary nails. Thus, problems such as improper conglutination, conglutination in rotation, nail breakage have been tried to be avoided. However, during the passage and locking of the locking screws through the intramedullary nail, the X-ray emitting scoping device must be used. Locking can be done easily with the help of the guides in the proximal region (close to where the nail is sent into the bone). This is a problem for the distal (distal end of the nail in the bone) locking screws. The externally applied guides, due to the metal flexion of the intramedullary nail in the bone, fail to find the target for this region. Many different methods have been developed to solve this problem. Guides with distal movement that find the target with the help of scoping, and systems that find the target with the help of navigation have been developed. However, since these systems are expensive and are not easily accessible, many orthopedic surgeons still apply the technique called "free hand", i.e locking screws under long-term radiation with the aid of a scope. In particular, patient position, scopy device used, the surgeon's experience, whether or not the motor used for the drill has passed the beam is directly related to the dose of X-ray received.

One of the biggest problems in applying intramedullary nails (IMN) used in the treatment of fractures of long bones is experienced during the application of distal locking screws. The guides used for the application of these screws can not catch the holes of the distal locking screws due to the stretching of the intramedullary nails. For this reason, the distal locking screws are screwed under the X-ray emitting scopy device. This causes both the patient and the practicing team to have X-rays at serious doses, and sometimes to open wrong holes in the bones to catch the hole center in the intramedullary nails.

In patent application TR2014/05497 we have introduced a distal locking mechanism which will solve the technical problems described above. This distal locking mechanism can only be applied to the femur bone. It is not possible to be applied on long bones (lower and upper extremities) like Tibia. It is not in a structure that conforms to the anatomical axis of the long bones except the femur, like the tibia. Also, there is no way to approximate the fracture line by compression and thus to accelerate the treatment.

The wall thickness has been reduced due to the inner shell which is proxically delivered into the distal locking mechanism which we refer to in our patent application TR2014/05497. Therefore, the risk of fracture of the intramedullary nail is increased. The inner shell guide is used during the proximal delivery of the inner shell. It is possible for the inner shell to rotate around itself while being delivered via a guide. This makes it difficult to switch to the next process step by combining the inner shell with the first distal locking screw.

With reference to our patent application TR2014/05497, the locking of the distal portion of the intramedullary nail is applied by free hand technique. In this system, the place where the first distal locking screw is applied is very important because the distance between the second screw is fixed. While there is no problem if the first screw is applied to the lower regions of the channel in the distal locking region of the intramedullary nail, if the first screw is applied to the upper region of the channel, second distal locking screw cannot be applied since the distance required for the locking screw to be applied exceeds the channel length. This situation complicates and extends the procedure in terms of physicians and patients.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to a new distal locking mechanism which will solve the aforementioned technical problems and provide comfort to the physician and the patient. It is provided by the invention that the application of the distal locking screws of the intramedullary nails can be performed independently of the patient position. It also speeds up the treatment process by bringing the fracture line together with a compress. With the free hand technique of the physician, by increasing the position options of the distal locking screws, the risks of secondary fractures due to wrong holes in the patient will be eliminated.

MEANINGS OF FIGURES

Figure 1 . Assembled Overview

Figure 2. Assembled Side View

Figure 3. A-A Section View

Figure 4. Side View of Intramedullary Nail

Figure 5. B-B Section View

Figure 6. C Detail View

Figure 7. View of the Mounting Set Consisting of Distance Control and

Compression Screw, and Inner Shell

Figure 8. Inner Shell Perspective View

Figure 9. View of Rotating Guide, Distance Control And Compression Screw, Inner Shell Mounting Set On First Distal Locking Screw

Figure 10. Screwdriver and Drill Guide Bed Guide and Distal Locking Screw Assembled View

Figure 1 1 . Screwdriver and Drill Guide Bed Guide and Distal Locking Screws Perspective View

Figure 12. Distance Control and Compression Screw Overview

Figure 13. Second Distal Locking Screw Overview

Figure 14. Assembled View of Distal Locking Screws On Distance Control and Compression Screw, Inner Shell Mounting Set

Figure 15. Screwdriver and Drill Guide Bed Overview The correspondence of the part numbers indicated in the figures are given below.

1 . Intramedullary Nail

1 .1 . Distal Locking Region

1 .2. Inner Shell Linear Movement Bed

1 .3. Distance Control and Compression Screw Bed

1 .4. End Screw Bearing

2. First Distal Locking Screw

2.1 . Centering Ridge

2.2. Trace

3. Second Distal Locking Screw

4. First Screwdriver Guide

5. Screwdriver and Drill Guide Bed

5.1 . First Locking Screw Bed

5.2. Second Locking Screw Bed

5.3. Option Locking Screw Bed

6. Inner Shell

6.1 . Linear Centering Bed

6.2. Second Distal Locking Screw Hole

6.3. Option Locking Screw Hole

6.4. Distance Control and Compression Screw

6.5. Channel

7. Rotation Guide

8. End Screw

DETAILED DESCRIPTION OF INVENTION

Invention is characterized with the parts; an intramedullary nail (1 ) containing an extended chamfered distal locking region (1 .1 ), an inner shell linear motion bed (1 .2), a distance control and compression screw bed (1 .3), an end screw bed (1 .4), a screwdriver and drill guide bed (5) containing an option locking screw bed (5.3), an inner shell (6) containing a linear centering bed (6.1 ), option locking screw hole (6.3), distance control and compression screw (6.4), and channel (6.5), rotation guide (7) and end screw (8).

Preparing the intramedullary nail (1 ) for use; The distance control and compression screw (6.4) and the inner shell (6) are connected by press. These two parts can perform independent circular motion around their axes while performing linear motion together. The mounting set consisting of the distance control and compression screw (6.4) and the inner shell (6) combined with the press before the end screw (8) of the intramedullary nail (1 ) is mounted, is attached to the rotation guide (7) which is fed through the intramedullary nail (1 ). While being drawn into the intramedullary nail (1 ), it is placed in the inner shell linear motion bed (1 .2) in the intramedullary nail (1 ) with the linear centering bed (6.1 ) on the inner shell (6). Subsequently, the mounting is provided by turning the distance control and the compression screw (6.4) which can move circularly independent of the inner shell (6), with the help of the rotation guide (7) in the distance control and compression screw bed (1 .3). The end screw (8) is fitted to the end screw bed (1 .4) to provide rigid engagement with the intramedullary nail (1 ).

How the system works can be described as follows with an exemplary operation. First, following fracture reduction, the intramedullary nail (1 ) with an appropriate size and radius is delivered to the bone medulla. After completing the necessary procedures for fracture stabilization, the treatment of the distal locking screws is performed. The first distal locking screw (2) can be delivered under scopy control, or without scoping, taking into account that the chamfered distal locking region with increased channel length (1 .1 ) in the intramedullary nail (1 ) can be easily gripped. The first distal locking screw (2) is attached to the screwdriver and is thrown into the distal locking region with the free hand technique. The trace (2.2) on the first distal locking screw (2) is positioned to face the vertical axis (the direction facing the proximal side). Then, the rotation guide (7) is sent from the proximal end of the intramedullary nail (1 ). It is fitted to the control and compression screw (6.4) inside the intramedullary nail (1 ). With circular motion, mounting set consisting of the distance control and compression screw (6.4) and the inner shell (6) is moved linearly and is fitted on the centering ridge (2) of the first distal locking screw (2).

First distal locking screw (2) should be inserted to the axes of intramedullary nail (1 ) with a vertical angle that is as high as possible, because inner shell (6) has to be ensured that it has maximum contact surface with first distal locking screw (2). If the channel inside the intramedullary nail is misaligned from the axis, against the possibility of any movement in the transverse axis of the distal locking screw sent from the outer cortex of the bone in the distal region, this misalignment is eliminated with the help of a bevel at the channel edge in the distal locking zone (1 .1 ).

It shall be easily understood that whether the first distal locking screw (2) passes through the intramedullary nail (1 ) or not when the inner shell (6) is delivered through the intramedullary nail (1 ). If first distal locking screw (2) is inside the intramedullary nail (1 ), inner shell (6) shall stop when it reaches the level of the first distal locking screw (2). If first distal locking screw (2) is outside the intramedullary nail (1 ), inner shell (6) shall slide more towards distal than it should be. It should be ensured that the centering cradle (2.1 ) and the channel (6.5) are positioned against each other. For this, the rotation guide (7) can be pressed down a certain amount.

The first screwdriver guide (4) has a flattened surface. This way, the circular positioning of the other two screwdriver guides is provided. First screwdriver guide (4) is fitted on the first distal locking screw hole (5.1 ) on the screwdriver and drill guide bed (5). Thus, the second distal locking screw (3) is delivered with the aid of the screwdriver guide (5.2) through the second locking screw hole (5.2), in a smooth fashion and without the need to use the scoping device. In case the position of the first distal locking screw (2) is not suitable for delivering the second distal locking screw (3) through the second distal locking screw bed (5.2), second distal locking screw (3) shall be applied to the option locking screw hole (6.3) by using the option locking screw bed (5.3). The first screwdriver guide (4), the other screwdriver guides and the screwdriver and the drill guide bed (5) are separated from the system. Depending on the condition of the fracture line, the distance control and compression screw (6.4) is rotated with the help of the rotation guide (7) in the intramedullary nail (1 ) and the inner shell (6) is pulled up to provide compression.

Following the above steps, surgeries with maximum patient and physician comfort, where the patient and the physician are not exposed or minimally exposed to X rays, can be performed. It will also greatly facilitate the surgical team and the surgeon by eliminating the need for constant changing of the patient position during surgery. In addition, this system will allow the distal locking screws to be mechanically locked with the nail. This in turn will allow the distal screw to be mechanically stronger and the system as a whole more stable.