Pelvic pin guide system for insertion of pins into iliac bone

A pelvic drill guide apparatus is used to insert external fixation pins into a patient's pelvis that is fractured (for example as a result of trauma such a automobile roll-over) in "open book" fracture fashion. Multiple fixation pins are placed into the pelvis on each side (for example 2 pins on each side). An external fixation frame holds the pins and thus the pieces of the pelvis together. The guide apparatus includes an elongated probe to track the surface of the pelvis at the inner table of the pelvis. A barrel portion of the guide apparatus tracks a drill to form surgical openings that begin at the iliac crest. The drill path is off-set slightly with respect to the tip of the probe so that the surgeon can drill holes in the pelvis with minimal invasion.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to orthopedic surgical instruments, and more 
particularly to a guide system for insertion of pins into a patient's 
iliac bone when serious disruption of the pelvic ring occurs (eg. an 
automobile accident) requiring stabilization with an external fixation 
device in the early stages of treatment, and wherein the guide system 
facilitates the insertion of pins into the iliac bone and shortens the 
time for surgery, independently of the external fixation system used. 
2. General Background 
When serious disruption of the pelvic ring occurs stabilization with an 
external fixation device can be of great benefit to the patient in the 
early stages of treatment. Blood loss is reduced by prompt application of 
an external fixation device. 
SUMMARY OF THE PRESENT INVENTION 
The present invention provides a system for the insertion of pins into a 
patient's iliac bone after injury that creates disruption of the pelvic 
ring. As a pre-operative preparation, the patient is placed in the supine 
position on an image intensification table. Image intensification may be 
used to confirm reduction and proper placement of fixator pins. The pelvis 
must be relatively reduced prior to incision to avoid undo tissue tension 
at the pin sites. 
A small incision (for example 2 centimeters) is made on either side of the 
pelvis, just proximal to the ASIS (Anterior Superior Iliac Spine) and 
exposing the iliac crest. The muscle is elevated medial to the iliac crest 
and the distal free tip portion of the guide apparatus of the present 
invention is inserted and pushed along the inner table of the pelvis. The 
guide instrument is then centered on the pelvic rim in such a manner that 
the pins can be inserted through the guide apparatus in an anteroposterior 
direction almost perpendicular to the plane of the operating room table. 
A drill guide is inserted into the instrument barrel bore. A pilot hole is 
drilled through the cortex of the iliac crest into the iliac bone. The 
guide prevents inadvertent penetration of either cortex from occurring. 
After withdrawal of the drill bit, a fixation pin is manually inserted 
through the guide apparatus using a T-wrench for example. A second pilot 
hole is drilled in a similar fashion and a second fixation pin is inserted 
using a T-wrench for example. This similar procedure is performed on the 
contralateral ilium. In emergency applications, both sides can be done 
simultaneously by two surgeons, to expedite pin placement. 
With the four pins in place, an external fixation system can be mounted to 
the pins for stabilizing the patient's fractured pelvis. 
The present invention thus provides an improved guide system for insertion 
of pins into the iliac bone. The pelvic pin guide apparatus of the present 
invention includes an instrument body that has a handle for gripping and 
manipulating the instrument body during placement of surgically drilled 
holes and insertion of pins in the patient's pelvis. 
The instrument body includes a tubular barrel with a central longitudinal 
bore, preferably cylindrically shaped. A pointer extends from the 
proximate end of the barrel and along a line that is generally parallel 
and off-set from the central longitudinal axis of the bore of the tubular 
barrel. The pointer is provided for tracking the surface of the inner 
table of the pelvis prior to the placement of surgically drilled holes 
that will accept fixation pins. 
The pointer includes a distal tip portion that is off-set a few millimeters 
from the central longitudinal axis of the barrel and spaced away from the 
distal end of the barrel along a line that coincides with the central 
longitudinal axis of the barrel. 
The bore is sized and shaped to hold an elongated drill. The pointer is 
positioned adjacent to the outer surface of the drill when the drill is 
extended fully through the barrel to the pointer tip. When the user places 
the free distal tip of the pointer in a desired position along the inner 
table of the pelvis, the user then knows that the drill will not out- crop 
during placement of the surgically placed openings that will carry the 
fixation pins. The drill will track a path that is slightly offset from 
the pointer tip and thus under the pelvic table surface when the pointer 
is engaged with the table surface. The barrel can provide a first larger 
bore for receiving one of a set of sleeves of various sizes, namely 
providing different internal diameter bores. Thus, the sleeve can 
removably fit the bore of the barrel, the sleeve having a sleeve bore that 
conforms to the outer surface of the drill during use. 
In the preferred embodiment, the pointer is an elongated member that is 
affixed to the outer surface of the barrel. 
The handle includes a strut that affixes to the outer surface of the barrel 
and extends laterally away from the barrel. 
A distal end portion of the barrel is provided with teeth for gripping the 
patient's tissue at the pelvis when the surgeon is preparing to place 
surgically formed holes in the patient's pelvis. 
The gripping surface of the distal end of the barrel can comprise a pair of 
circumferentially spaced teeth at the distal end of the barrel. 
The handle and the pointer are spaced circumferentially about the barrel at 
opposed positions preferably about one hundred eighty degrees 
(180.degree.) apart about the outer surface of the barrel. 
The method of the present invention provides an improved method for 
inserting pins into the iliac bone of a patient. The surgical steps 
include the first step of forming an incision on the side of the patient's 
pelvis just proximal to the ASIS, exposing the iliac crest. Muscle is then 
elevated medial to the iliac crest. 
The drill guide is used to track the drill into the patient's pelvis, 
through the cortex of the iliac crest and into the iliac bone along a path 
that prevents inadvertent penetration of either cortex. 
The method preferably includes the placement of a plurality of drilled 
openings on spaced apart locations. The drill preferably occupies a 
position within the bore of the drill guide and the pointer extends to the 
distal end of the drill guide at a position adjacent the drill outer 
surface when the drill is extended to the distal end of the drill guide. 
The surgeon places a plurality of pins respectively in the plurality of 
drilled openings and then mounts an external fixation system to the pins 
after placement in the surgically formed openings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIGS. 1-3 and 6-7 illustrate a first preferred embodiment of the apparatus 
of the present invention designated generally by the numeral 10. Pelvic 
drill guide 10 includes an instrument body 11 that includes a barrel 12, 
handle 20 and a probe 24. Barrel 12 includes a proximal end 13 and distal 
end 14. Barrel 12 has a generally cylindrically shaped longitudinally 
extending, open ended bore 15 for receiving a drill during use. 
Barrel 12 includes an enlarged central cylindrical portion 19 a smaller 
proximal cylindrical portion 16 and a smaller cylindrical portion 17 at 
distal end 14. Distal end 14 of barrel 12 carries a pair of teeth 18 that 
are circumferentially spaced about the smaller cylindrical portion 17 of 
barrel 12 as shown in FIG. 7. Teeth 18 project forward in a line that is 
generally parallel to the central longitudinal axis of bore 15. The teeth 
18 are used to grip the patient's tissue at the pelvis as shown in FIG. 4. 
The surgeon places the instrument body 11 in a desired position and then 
surgically forms drilled openings in the patient's pelvis. Barrel 12 
includes enlarged section 19 to which is attached handle. The handle 20 
includes a gripping surface 21 and arm 23 that extends between gripping 
surface 21 and enlarged portion 19 of barrel 12 at connection 22. 
Elongated probe 24 of pelvic drill guide 10 includes a straight section 26 
that is attached by welding for example to the outer surface of enlarged 
section 19 of barrel 12. The probe or tip 24 also includes a bend 27, 
straight section 28, bend 29, straight section 30, bend 31, and straight 
section 32. The probe 24 carries a pointed distal tip 33. 
During use, the surgeon inserts the probe 24 along the inner table of the 
pelvis P until the teeth 18 engage the pelvic rim. The distal tip 33 is 
engaging the inner table of the pelvis and the teeth 18 of the barrel 12 
engage the iliac crest. In this position (see FIG. 4), the surgeon can 
place a drill 34 into the central longitudinally extending bore 15 of 
barrel 12 to form surgically drilled openings in the patient's pelvis P. 
The drill 34 as seen is FIG. 2, can be generally cylindrically shaped, 
having a larger cylindrical portion 35, a smaller cylindrically shaped 
cutting portion 37, and an annular shoulder 36 positioned between the 
section 35, 37. The drill 34 includes a cutting distal tip 38 and a 
proximal end that includes a plurality of flats 39 for forming a 
connection between the drill 34 and a drill chuck (not shown). 
Once the surgeon forms a plurality of drilled openings in the patient's 
pelvis, a plurality of fixation pins 40 can be placed into those openings. 
An acceptable pin 40 is shown in FIG. 3 that includes a cylindrical 
unthreaded section 41, a helically threaded section 43, and a distal tip 
44 that can define a self tapping thread. Arrow 42 indicates the position 
between the threaded and non-threaded sections 43,41. 
In FIGS. 4-5 and 8-10 the method of the present invention is illustrated 
more particularly. In FIG. 4, the surgeon has placed instrument body 10 in 
proper position before inserting drill 34 into the bore 15 of barrel 12. 
In FIG. 4, the surgeon has already formed a small incision (for example 
two (2) centimeters) on the side of the pelvis just proximal to ASIS and 
exposing the iliac crest 47. 
The muscle is elevated medial to the iliac crest and the free tip 33 of 
guide apparatus 10 is inserted and pushed along the inner table 45 of the 
pelvis P. The guide apparatus 10 is centered on the iliac crest 47 in such 
a manner that pins 40 will be inserted in an anteroposterior direction 
almost perpendicular to the plane of the operating table. Drill 34 is 
inserted into bore 15 of barrel 12 as shown in FIG. 5 and a pilot hole is 
drilled through the cortex of the iliac crest into the iliac bone. 
The guide apparatus 10 prevents inadvertent penetration of either cortex 
from occurring. After withdrawal of the drill 34 and guide apparatus 10, a 
fixation pin 40 is manually inserted using a T-wrench, for example. A 
second surgically formed pilot hole is drilled in a similar fashion and a 
second pin 40 is inserted again by means of a T-wrench, for example. In 
FIG. 9, the surgically formed openings are indicated in phantom lines by 
the numeral 46. The surgeon can then mount a conventional external 
fixation system 75 to the pins 40, as shown in FIG. 9. 
In FIG. 1, the numeral 50 indicates the central longitudinal axis of the 
cylindrically shaped bore 15 that extends longitudinally through barrel 
12. The pointed tip 33 is spaced a few millimeters (for example three (3) 
millimeters) from the central longitudinal axis 50. This places the 
pointer tip 33 adjacent the outer surface of drill 34 at cylindrically 
shaped cutting portion 37. 
By placing the tip 33 on the patient's inner table 45 (as shown in FIG. 4), 
at the position indicated by arrow 48 in FIG. 4, the surgeon insures that 
the drill will track into the patient's pelvis but not break through the 
surface 45 or outcrop inadvertently. Rather, the tip 33 is placed tightly 
against the surface 45 and the drill tracks under the surface 45. This 
insurance is provided by the geometry of the central longitudinal axis 50 
being off-set with respect to the pointer tip 33. 
In FIGS. 11-12, the barrel 12 has a bore 15A that is sized and shaped to 
receive interchangeable sleeves 51, 53 each having an internal sleeve bore 
52,54 respectively. This allows different diameter drills 34 to be used 
with the same instrument body 11. Each sleeve 51, 53 has a large 
cylindrical collar 52A, 54A respectively that acts as a stop (see FIG. 12) 
when sleeve 51, 53 occupies bore 15A of barrel 12. 
FIGS. 13-16 illustrate a third embodiment of the apparatus of the present 
invention designated generally by the numeral 57. Drill guide apparatus 57 
provides an instrument body 58 having a distal end 59 and a proximal end 
60. As with the first and second embodiments, a longitudinally extending 
open ended bore is provided for receiving a drill during use. The method 
of the present invention is the same with the embodiment of FIGS. 13-16 as 
with the embodiments of FIGS. 1-12. However, in the embodiment of FIGS. 
13-16, a locking collar is provided for locking a probe in position 
wherein the probe pivots about the instrument body 58. Instrument body 58 
includes a larger cylindrical section 62 and a smaller cylindrical section 
63. Smaller cylindrical section 63 carries a pair of teeth 64 at distal 
end 59 of the apparatus 57. The apparatus 57 is supported using handle 65 
that is connected with strut 66 to instrument body 58. 
Locking collar 67 is generally cylindrically shaped, and affixes to a 
smaller diameter cylindrically shaped section 68 of larger cylindrical 
section 62. Locking collar 67 is in the form of an elongated hollow 
cylinder having a longitudinal slot 69. The slot 69 can be aligned with 
probe 72 (see FIG. 15). In this position, the probe can pivot about pivot 
71, allowing the probe to move away from the central longitudinal axis of 
bore 61 as shown in FIG. 14. Probe 72 has a configuration similar to the 
configuration of the probes of the embodiments shown in FIGS. 1-12. 
The locking collar 67 is a regular cylinder which rotates around instrument 
body 58 and more particularly around the larger cylindrical section 62 
thereof. Locking is obtained by simply rotating the collar 67. The probe 
72 is "buried" in the thickness of the drill sleeve, occupying a position 
in longitudinally extending recess 70. In locking position as in open 
position, the collar 67 does not protrude beyond instrument body 58 as 
shown in FIGS. 13-16. 
The hinged probe 72 pivots about pivot 71 when the guide 57 is removed from 
the patient. The hinged probe 72 prevents the tip 73 from catching the lip 
of the iliac crest when the guide apparatus 57 is removed from the 
patient. 
The following table lists the part numbers and part descriptions as used 
herein and in the drawings attached hereto. 
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TS LIST 
Part Number Description 
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10 pelvic drill guide apparatus 
11 instrument body 
12 barrel 
13 proximal end 
14 distal end 
15 cylindrical bore 
15A cylindrical bore 
16 cylindrical portion 
17 cylindrical portion 
18 teeth 
19 enlarged section 
20 handle 
21 gripping surface 
22 connection 
23 arm 
24 probe 
25 connection 
26 straight section 
27 bend 
28 straight section 
29 bend 
30 straight section 
31 bend 
32 straight section 
33 pointed tip 
34 drill 
35 larger cylindrical portion 
36 annular shoulder 
37 smaller cylindrical 
cutting portion 
38 cutting tip 
39 tool flats 
40 pin 
41 cylindrical unthreaded section 
42 arrow 
43 threaded section 
44 cutting tip 
45 inner table 
46 pilot hole 
47 iliac crest 
48 arrow 
49 arrow 
50 axis 
51 interchangeable sleeve - large bore 
52 internal sleeve bore (large) 
52A cylindrical collar - large bore 
53 interchangeable sleeve bore - small bore 
54 internal sleeve bore (small) 
54A cylindrical collar - small bore 
55 enlarged diameter collar 
57 drill guide apparatus 
58 instrument body 
59 distal end 
60 proximal end 
61 bore 
62 larger cylindrical section 
63 smaller cylindrical section 
64 teeth 
65 handle 
66 strut 
67 locking collar 
68 smaller diameter section 
69 slot 
70 longitudinal recess 
71 pivot 
72 probe 
73 tip 
75 conventional external fixation system 
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Because many varying and different embodiments may be made within the scope 
of the inventive concept herein taught, and because many modifications may 
be made in the embodiments herein detailed in accordance with the 
descriptive requirement of the law, it is to be understood that the 
details herein are to be interpreted as illustrative and not in a limiting 
sense.