Double nail guiding system for targeting of distal screw holes of interlocking nails

A double nail guiding system for stabilizing broken bones includes a twin jig, first and second interlocking nails extending from the twin jig, wherein each interlocking nail defines a channel along a longitudinal axis thereof. The interlocking nails also include a distal portion which includes at least one hole. A centric or eccentric guiding pipe, including a channel in the center, extends through the first interlocking nail in a direction toward the second interlocking nail. A K-wire is inserted into the channel in the guiding pipe, such that the K-wire extends through the guiding pipe and through the hole defined in the second interlocking nail which is in the bone being stabilized. A guide probe is inserted into the channel in the second interlocking nail (which is in the bone) toward the distal portion thereof. In this manner, alignment of the hole in the distal portion of the first interlocking nail and the hole in the distal portion of the second interlocking nail is confirmed by contacting the guide probe with the K-wire. Advantageously, the first interlocking nail and the second interlocking nail are constructed to be of equal length and equal size.

BACKGROUND OF THE INVENTION 
Successful placement of the distal screws into a tibial and femoral 
interlocking nail without roentgenogram assistance is a technically 
demanding procedure, because the accuracy of the targeting device included 
in the original systems requires a time wasting and inaccurate method. 
Furthermore, the most commonly used technique for distal interlocking 
screw placement is the freehand method. However, the freehand method still 
includes the drawbacks of time expenditure and radiation exposure. 
Therefore, it is an object of the present invention to provide a new 
guiding system which may obviate and mitigate the above-mentioned 
drawbacks. 
SUMMARY OF THE INVENTION 
This invention relates to a double nail guiding system. 
It is the primary object of the present invention to provide a double nail 
guiding system which includes a combination of two interlocking nails of 
equal length and/or size for the distal screw targeting procedure. 
It is another object of the present invention to provide a double nail 
guiding system which is simple in structure. 
It is still another object of the present invention to provide a double 
nail guiding system which is easy to adjust during the operation. 
It is still another object of the present invention to provide a double 
nail guiding system which is economical to produce. 
It is still another object of the present invention to provide a double 
nail guiding system which is accurate during the operation. 
It is still another object of the present invention to provide a double 
nail guiding system which markedly saves operation time. 
It is still another object of the present invention to provide a double 
nail guiding system which is radiation-free in the process of targeting 
the distal interlocking screws during the operation. 
It is a further object of the present invention to provide a double nail 
guiding system which can be used for a long time. 
Other objects and merits and a fuller understanding of the present 
invention will be obtained by those having ordinary skill in the art when 
the following detailed description of the preferred embodiment is read in 
conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to the drawings, and in particular to FIG. 1 thereof, the 
double nail guiding system in accordance with the invention includes a 
tibial twin jig (1) which may be connected to two nails (3,4) of equal 
length with two separate holding screws (2). The nail that will be driven 
into the fractured tibia is called the "true nail". The other nail at the 
medial border of the leg is called the "guiding nail" based on its use as 
a guide. For example, in right tibia unstable fractures, the left side 
interlocking nail (3) of this combination is the true nail which will be 
inserted into the fractured tibia. The right side nail (4) on the medial 
side of the leg acts as a guiding nail. Alternatively, in left tibia 
unstable fractures, the right side nail (4) acts as the true nail, and the 
left side nail (3) acts as the guiding nail. 
As shown in FIG. 2, using the double nail guiding system in accordance with 
the invention, a K-wire (5) and an eccentric guiding pipe (6) are used in 
targeting the most distal screw hole of the true nail (3) inside the 
tibia. Due to the fact that the position of the distal screw holes of the 
tibia interlocking nail may include errors as a result of manufacturing, 
sets of centric and eccentric pipes are designed to correct these 
intrinsic errors. 
Additionally, a guiding probe (7) is put into the true nail (3) from the 
proximal end to the distal end to make sure that the K-wire (5) is 
transfixing through the most distal screw hole of the true nail (3). A 
metallic sound may be heard when the guiding probe (7) hits the K-wire 
(5). Thereafter, the K-wire (5) and the guiding pipe (6) are removed. 
FIG. 3 shows a drill (8) going through the K-wire (5) pre-drilled cortices. 
The guiding probe (7) may be used again to make sure that the drill (8) is 
transfixing the true nail (3). Thereafter, the drill (8) and the guiding 
nail (4) are removed. 
FIG. 4 shows a screw (9) being driven into the true nail (3). The guiding 
probe (7) may be used to make sure that the screw (9) is driven at the 
proper location. No radiation exposure is necessary. 
The targeting of the second distal interlocking screw hole of the tibia 
interlocking nail is performed following the same procedures described 
above. 
FIG. 5 illustrates an exploded view of a femoral twin jig (10) according to 
the present invention. The femoral twin jig (10) may be connected to two 
nails (11,12) of equal length with two separate holding screws (2). The 
nail that will be put into the fractured femur is called the "true nail". 
The other nail at the lateral border of the thigh is called the "guiding 
nail" based on its use as a guide. For example, in right femoral unstable 
fractures, the left side interlocking nail (11) of this combination is the 
true nail which will be inserted into the fractured femur. The right side 
nail (12) on the lateral side of the leg acts as the guiding nail. In left 
femoral unstable fractures, the left side nail (11) still acts as the true 
nail and the right side nail (12) acts as the guiding nail. Due to the 
fact that the position of the distal screw holes of the femoral 
interlocking nail may include errors as a result of manufacturing, sets of 
eccentric pipes are designed to correct these intrinsic errors. 
As shown in FIG. 6, using the double nail guiding system in accordance with 
the invention, a K-wire (5) and an eccentric guiding pipe (6) are used to 
target the most distal screw hole of the true nail (11) inside the femur. 
Additionally, a guiding probe (7) is put into the true nail (11) from the 
proximal end to the distal end to make sure that the K-wire (5) is 
transfixing through the most distal screw hole of the true nail (11). A 
metallic sound may be heard when the guiding probe (7) hits the K-wire 
(5). Thereafter, the K-wire (5) and guiding pipe (6) are removed. 
FIG. 7 shows a drill (8) going through the K-wire (5) pre-drilled cortices. 
The guiding probe (7) may be used again to make sure that the drill (8) is 
transfixing the true nail. Thereafter, the drill (8) and guiding nail (12) 
are removed. 
FIG. 8 shows a screw (9) being driven into the true nail (11). The guiding 
probe (7) may be used to make sure that the screw (9) is driven at the 
proper location. No radiation exposure is necessary. 
The targeting of the second distal interlocking screw hole of the femur 
interlocking nail is performed following the same procedures described 
above. 
It should be noted, however, that the present invention (DNRG system) may 
be used for targeting different types of interlocking nails. 
The interlocking nails in accordance with the invention may be used for 
long bone fractures, such as tibia, femur, humerus, radius, ulna, 
metacarpal and metatarsal fractures. 
The application of the present invention is too wide to be mentioned and 
cannot be all enumerated here in detail. It is understood that the present 
disclosure is made by way of example only, and that numerous changes in 
the detail of the construction and combination of parts may be resorted to 
without departing from the spirit and scope of the invention as 
hereinafter claimed.