A hemi-laminectomy retractor attachment device adapted for use with prior art retractors. In a preferred embodiment the device includes two hook-shaped members that are joined together by a length of strong, flexible cord. The hook-shaped members are narrow enough to fit between spinal bones to brace against the spinal ligaments, and the cord is engaged with the retractor arm.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to surgical retractors and more particularly 
to an attachment that is particularly suited for use in hemi-laminectomy 
surgical procedures. 
2. Description of the Prior Art 
Retractors that are utilized in laminectomy and hemi-laminectomy surgery 
are formed with blade-like attachments for gripping and manipulating 
spinal muscles. Such blades typically have a plurality of prongs or smooth 
surfaces to pull muscles to one side or hold muscles in an appropriate 
place to facilitate the gripping of the muscle. 
In performing a hemi-laminectomy procedure, one blade of a retractor grips 
the spinal muscle in the typical manner. The other blade is preferably 
adapted to fit between two adjacent spinal bone elements and engage a 
spinal tendon that resides next to the bone elements. It is often the case 
that insufficient spacing exists between the adjacent bone elements to 
permit the hemi-laminectomy device to pass therebetween. This situation 
occurs because the prior art hemi-laminectomy attachments are relatively 
thick in diameter and the patient's spinal column spacing may be 
insufficient due to age or deterioration. Such relatively thick retractor 
elements also may obstruct visualization of the exposed area. A relatively 
thick retractor element is necessary in the prior art configurations due 
to the requirement for significant bending strength in order for the 
device to perform properly. 
Applicant is aware of several U.S. patents for retractors. Williams U.S. 
Pat. No. 4,034,746 teaches a scissor-like retractor having a blade member 
and a rod-like member that are utilized to open an incision for surgical 
procedures. Another relevant retractor is depicted in U.S. Pat. No. 
2,450,194. U.S. Pat. Nos. 4,430,911 to Darnell, 4,274,398 to Scott, Jr., 
3,823,709 to McGuire, and 3,762,401 to Tupper all teach other types of 
surgical retractors, the relevant features of these patents being the 
utilization of hook-shaped tissue-holding members that are utilized to 
hold an incision open for surgical procedures. However, none of the prior 
art devices and patents known to Applicant contain all of the features of 
Applicant's invention, which are particularly suited for hemi-laminectomy 
surgical procedures. 
There is therefore a need for a hemi-laminectomy retractor attachment which 
easily fits between minimally-spaced spinal bone elements, yet is strong 
enough to withstand pressure while fitting a wide range of sizes and 
shapes of spinal areas. 
SUMMARY OF THE INVENTION 
It is an object of the hemi-laminectomy attachment device of the present 
invention to provide a device having a minimal thickness such that it will 
easily pass between the bony elements of a patient's spinal process and 
elements. 
It is another object of the hemi-laminectomy attachment device of the 
present invention to provide a device which is strong enough to give and 
produce a better visualization of the operated area such that a surgeon 
can perform his/her surgery in a wide and more open space. 
It is a further object of the hemi-laminectomy attachment device of the 
present invention to provide a device that is adapted for use with most 
currently available laminectomy retractors. 
It is yet another object of the hemi-laminectomy retractor attachment 
device of the present invention to provide a device that is inexpensive 
and easy to use. 
The hemi-laminectomy attachment device of the present invention includes 
one or two hook-shaped members. Each hook-shaped member is formed with an 
eye at the shank end for attachment to a length of strong, flexible cable. 
In the two hook-shaped member embodiment the two hook-shaped members are 
joined together by a single length of cable. The diameter of the shank of 
each hook is sufficiently small to allow it to pass through narrow spaces 
between spinal bone elements, yet the strength of each hook-shaped member 
is sufficient to withstand bending pressure. 
It is an advantage of the hemi-laminectomy attachment device of the present 
invention that it provides a device having a minimal thickness such that 
it will easily pass between the bony elements of a patient's spinal 
process and elements. 
It is another advantage of the hemi-laminectomy attachment device of the 
present invention that it provides a device which is strong enough to give 
and produce a better visualization cf the operated area such that a 
surgeon can perform his/her surgery in a wide and more open space. 
It is a further advantage of the hemi-laminectomy attachment device of the 
present invention that it provides a device that is adapted for use with 
most currently available laminectomy retractors. 
It is yet another advantage of the hemi-laminectomy retractor attachment 
device of the present invention that it provides a device that is 
inexpensive and easy to use. 
The foregoing and other objects, features, and advantages of the present 
invention will be apparent from the following detailed description of the 
preferred embodiments which make reference to the several figures of the 
drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As depicted in FIG. 1, a preferred embodiment of the hemi-laminectomy 
retractor attachment device 10 of the present invention includes two 
hook-shaped members 12 and 14. Each hook-shaped member 12 and 14 is formed 
with a shank portion 16 and 18 respectively, a curved portion 20 and 22 
respectively having an arc of approximately 180 degrees, and a tip portion 
24 and 26 respectively. The distal end of the shank portion 16 and 18 
respectively is formed with an eye 28 and 30 respectively. A strong, 
flexible cord 32 is utilized to join the two hook-shaped members 12 and 14 
together by passing a first end of the cord 32 through eye 28 and the 
other end of the cord through eye 30. The ends of the cord are looped and 
engaged to the cord 32. The cord 32 may be formed from such materials as a 
length of wire, braided wire, chain or other material that is sufficiently 
strong yet flexible. 
The size of the hook-shaped members 12 and 14 may be varied according to 
the operational requirements. Thus, the radius of curvature of the curved 
portions 20 and 22 as well as the length of the shank portions 16 and 18 
and the length of the tip portions 24 and 26 may be varied to suit 
particular operational situations. Likewise, the length of the cord 32 may 
be altered to suit particular needs. In the preferred embodiment the 
radius of curvature of the curved portion 20 or 22 may vary according to 
the particular application but is approximately 1 centimeter, the length 
of the shank portion 16 and 18 is approximately 3 centimeters, the 
diameter of the shank portion may also vary but is approximately 2 
millimeters, the length of the tip portion 24 and 26 is approximately 1.5 
centimeters, and the length of the cable 32 is approximately 8 
centimeters. The preferred material for members 12 and 14 is stainless 
steel, and the cable 32 is formed from braided stainless steel wire which 
can be lengthened or shortened to fit one or several hemi-laminectomy 
areas. The cable also may be changed to any other material providing it 
will be strong and not tear during surgery. 
FIG. 2 depicts an alternative embodiment of the present invention 
comprising a single hook-shaped member 12'. As will appear from a 
comparison of FIGS. 1 and 2, corresponding portions of hook-shaped member 
12' are identified utilizing primed numbers corresponding to the numbering 
of FIG. 1. (able 32' of the hook-shaped member 12' of FIG. 2 is formed 
with a relatively large loop 34'. The dimensions of the preferred 
embodiment of the hook-shaped member 12' are substantially similar to 
those of the hook-shaped member 12 of FIG. 1. The length of the cable 32' 
is approximately 4 centimeters and the diameter of loop 34' is 
approximately 2.5 centimeters. 
FIG. 3 depicts the present invention of FIG. 1 as utilized with a prior art 
laminectomy retractor 40 that is more fully described in U.S. Pat. No. 
2,450,194. The retractor 40 is formed with two arms 42 and 44 that are 
moveable relative to each other through the utilization of a ratchet 
mechanism 46 which engages a plurality of teeth 48 formed on a ratchet bar 
50 that is fixedly engaged to arm 42. It will therefore be appreciated 
that arm 44 is slidably engaged to bar 50 and that the operation of 
ratchet 46 within the various teeth 48 of bar 50 will cause arm 44 to move 
laterally with respect to arm 42. 
As depicted in FIG. 3, a blade 52 having three prongs 54 is engaged to the 
distal end of the moveable arm 44. The hemi-laminectomy attachment device 
10 of FIG. 1 of the present invention is engaged to the fixed retractor 
arm 42. This engagement is accomplished through the looping of the cable 
32 around the arm 42, such that the hook-shaped members 12 and 14 are 
disposed toward the blade 52. A notch 56 may be formed in the distal end 
of arm 42, such that the cable 32 will reside in said notch, whereby the 
cable 32 will be inhibited from sliding off of the distal end of arm 42 
when the device is utilized. It will therefore be appreciated that upon 
the operation of ratchet 46 that arm 44 with its attached blade 52 will 
move laterally with respect to the fixed orientation of the hook-shaped 
members 12 and 14; that is, that the gap 58 between the prongs 54 and the 
hook-shaped members 12 and 14 is adjusted through use of the ratchet 
mechanism 46. 
The alternative embodiment of the present invention depicted in FIG. 2 is 
also formed for engagement with the arm 42 of the laminectomy retractor 40 
depicted in FIG. 3. The engagement is achieved by sliding the loop 34' 
over the projecting end of arm 42. If a notch 56 is provided in arm 42, 
the loop 34' would reside within the notch 56. 
FIG. 4 depict: a simplified drawing of a hemi-laminectomy operation 
utilizing the present invention depicted in FIG. 1. Five bony elements 60 
of the spinal column are shown separated by spinal discs 62. Two spinal 
muscles and tendons 64 and 65 are disposed parallel to the spinal column 
immediately next to the bony elements 60 thereof. The left side muscle 
sheath 66 is shown in its undisturbed position, whereas the right side 
muscle sheath 68 is shown pulled away by the prongs 54 of the blade 52 of 
a hemi-laminectomy retractor, such as that depicted in FIG. 3. A damaged 
portion 70 of a spinal disc 62 is revealed for surgical procedure. The two 
hook-shaped members 12 and 14 of the present invention are shown in 
position braced against the right side spinal tendon 65, each hook-shaped 
member 12 and 14 having passed between the protruding bony elements 60 of 
the spinal column. Because the tendon 65 is more firmly attached to the 
spinal column elements 60, the muscle sheath 68 is moved laterally by the 
widening of the gap 58 between the hook-shaped members 12 and 14 and the 
prongs 54 through the operation of the ratchet 46 of the retractor 40. 
As shown in FIG. 4, it is to be appreciated that hook-shaped members 12 and 
14 possess a sufficiently narrow diameter that they may be inserted 
between the spaces between the bony elements 60 to engage the spinal 
tendon 65. In many instances, such as with young patients or elderly 
patients or patients with differing growth patterns, the spaces between 
the spinal bony elements 60 may be quite narrow, such that prior art 
hemi-laminectomy devices will not fit through the narrow spaces between 
the bony elements. The prior art devices tend to be thicker in diameter 
because they are configured to withstand bending forces. The shanks 16 and 
18 of the hook-shaped members experience mainly tension forces and, owing 
to the nature of the material (stainless steel in the preferred 
embodiment), can be smaller in diameter. 
It is also to be realized that the device 10 is quite versatile in its 
applications. That is, the hook-shaped members need not be placed within 
two sequential gaps between bony members 60 as is depicted in FIG. 4. 
Specifically, hook-shaped member 14 could be disposed in gap 72 as 
identified in FIG. 4. Also, more than one of the devices 10 could be 
disposed upon a single retractor arm 42, whereby three or four hook-shaped 
members would be available for insertion between various of the bony 
elements 60 of the spinal column. Additionally, the multiple hook-shaped 
members need not be of the same size for some particular applications. 
While the invention has been particularly shown and described with 
reference to certain preferred embodiments, it will be understood by those 
skilled in the art that various alterations and modifications in form and 
detail may be made therein. Accordingly, it is intended that the following 
claims cover all such alterations and modifications as may fall within the 
true spirit and scope of the invention.