Contoured surgical table

A surgical table is provided for receiving and positioning a patient. The surgical table includes a chair which includes a backrest for receiving the upper body of a patient, and a pelvic support which supports the pelvic area of the patient across the sacrum. The pelvic support is designed such that it does not underlie at least one preselected hip joint of the pelvic area of the patient. The surgical table further includes a support structure which supports the chair at a predetermined elevated position and provides an unobstructed clearance of a predetermined height under the pelvic area of the patient. A leg support is provided for positioning the leg of a patient such that the thigh of the leg assumes an atavistic position.

BACKGROUND OF THE INVENTION 
The present invention relates generally to a surgical table and more 
particularly to a surgical table suited for surgery performed under x-ray. 
Recent developments in medical and surgical procedures have created a need 
for specialized surgical tables which position a patient in a 
predetermined posture. To this end a number of specialized tables and 
other devices have been developed, particularly in the fields of 
obstetrics and gynecology. For example, U.S. Pat. No. 3,817,512 (Torrey) 
discloses a device which may be used as a portable examination table to 
examine the pelvic or rectal area of a patient. The device disclosed by 
Torrey includes a table which is pivotally supported on a base and a pair 
of leg supports disposed on opposite sides of the table. During 
examination, the table is placed under the patient's buttocks and the 
patient's legs are placed in the adjustable leg supports. The table and 
leg supports are adjusted such that the patient assumes a position which 
properly exposes the area which is to be treated. 
U.S. Pat. No. 3,318,596 (Herzog) discloses a surgical table particularly 
suited for use in obstetrics. The surgical table includes adjustable leg 
rests articulated to a table which includes an adjustable backrest. The 
adjustment of the leg rests and the backrest may be synchronized to place 
the patient in a desired position for the physician. 
Other devices which may be used to position a patient during obstetric 
procedures are taught in: U.S. Pat. No. 4,557,260 (Reyes, Jr.) which 
discloses a hip lifter or pelvic support for supporting and positioning 
the pelvic portion of a patient in an elevated position during 
examination; U.S. Pat. No. 4,221,370 (Redwine) which discloses an 
obstetric chair which adjusts in elevation and attitude, and includes 
channel-like thigh supports to position the patient's legs; and U.S. Pat. 
No. 4,225,127 (Strutton) which discloses a device for positioning an 
expectant woman during child birth. The Stratton device includes a table 
(which forms a chair seat), a pivotally mounted chair back, and a pair of 
leg supports pivotally mounted from the table. This arrangement allows the 
position of the expectant woman to be changed from a supine position to a 
squatting position during delivery. 
Other devices are also available for positioning patients during post 
surgery treatment. For example, U.S. Pat. No. 3,759,252 (Berman) discloses 
an apparatus for hip dislocation treatment. The apparatus includes means 
for securing and immobilizing the leg and hip bones of a patient in a 
selected position during the healing period of the hip dislocation. 
Although the devices disclosed above are useful for gynecological, 
obstetric and post surgical healing procedures, they are not particularly 
well suited for surgery of the lower limbs of a patient. 
Although some efforts have been devoted to developing orthopedic operating 
tables for lower limb surgery, a surgical table which provides a 
comfortable arrangement for the patient has not been developed. Existing 
tables such as the "Orthopedic System Orthomicron," which is commercially 
available from Marzet Aubry of Paris, France, are designed for lower limb 
surgery work performed under x-ray control devices such as C-arm image 
intensifiers. The Marzet Aubry table includes a traction arm which may be 
articulated in any direction, a pelvic support which adjusts horizontally 
to accommodate the use of x-ray machines such as the C-arm, and a table 
top which supports the upper body of a patient. The traction unit is 
adjustable in abduction, adduction and also in tilting to accommodate 
surgery on a flexed leg. The table provides unobstructed access to the 
pelvic area of a patient. Although this design accommodates surgical 
procedures which require the use of C-arm x-ray machines, the design and 
construction of this table are not ideally suited for the comfort of the 
patient. Further, the Marzet Aubry table is not operative to adequately 
secure a patient in the atavistic position (discussed below) which is 
desirable in certain surgical procedures. 
As stated above, the design and construction of existing lower limb 
surgical tables may provide a source of discomfort for patients. First, 
the construction of existing tables makes it difficult for a patient with 
a lower limb injury to climb onto the table. Second, the table typically 
includes a post which is disposed in the perineum (crotch area) of the 
patient for securing the patient on the table. This post provides a source 
of discomfort, particularly when the patient's legs are in traction. 
For surgical procedures such as the method of installing an endoprosthesis 
in the hip taught in U.S. Pat. No. 4,714,478 (Fischer), it is particularly 
desirable for the thigh of the patient to be in an atavistic position. An 
atavistic position is defined as the position of the thigh such that the 
femoral head is completely within the acetabulum. A patient's femoral head 
is normally one-third outside of the acetabulum when the patient is in a 
supine position. Typically, the atavistic position is assumed at 
80.degree. flexion and 10.degree. abduction. 
In the method taught by Fischer, a portal is drilled through the lateral 
cortex of the femur at a location opposite the ball of the femur. The ball 
of the femur is then removed by drilling through the femoral neck into the 
femoral head. The endoprosthesis is then inserted through the portal. The 
procedure is facilitated if the femoral head is completely within the 
acetabulum. It is also desirable for a surgical table used in such a 
procedure to provide unobstructed lateral access to the pelvic area as 
well as an unobstructed x-ray path through the hip joint. 
Although existing surgical tables may be adjusted to position the leg of a 
patient, they do not provide adequate measures for positioning the leg of 
a patient such that the thigh assumes the anatomical thigh position (the 
atavistic position). Further, existing surgical tables such as the Marzet 
Aubry device, when used to position the patient's leg in a flexed 
position, do not fully secure the leg to a point where the surgical 
procedure taught by Fischer may be performed. 
Therefore, in view of the above, it is an object of the present invention 
to provide a comfortable surgical table which provides unobstructed 
lateral access to the pelvic area of a patient. 
It is a further object of the present invention to provide a surgical table 
which may be used to position and secure the thigh of a patient in a 
predetermined degree of abduction and flexion. 
It is still a further object of the present invention to provide a surgical 
table which may be used for x-ray controlled surgical procedures in the 
pelvic area. 
SUMMARY OF THE INVENTION 
To achieve the foregoing and other objects and in accordance with the 
purposes of the present invention, the surgical table of the present 
invention may comprise a chair for receiving a patient, means for securing 
the patient in the chair, means for supporting the chair in an elevated 
position, and means for supporting a leg of the patient in a predetermined 
position. The chair includes a backrest for receiving the upper body of a 
patient, and pelvic support means for supporting the pelvic area of the 
patient across the sacrum. The pelvic support means is configured such 
that it does not underlie at least one preselected hip joint of the pelvic 
area. The chair support means positions the chair at a predetermined 
elevation and provides an unobstructed clearance below the pelvic area of 
the patient. The leg support means positions the leg associated with the 
preselected hip joint such that the thigh of the leg assumes an atavistic 
position. 
Medical procedures, such as the hip replacement procedure taught by 
Fischer, which require the use of sophisticated x-ray devices may be 
performed on the surgical table of the present invention. The surgical 
table of the present invention provides an unobstructed x-ray path through 
the hip joint of the patient, thus providing an interference free path for 
C-arm x-ray equipment. The surgical table also provides lateral access to 
the pelvic area of the patient. Since the leg of the patient may be 
positioned to assume the atavistic position, procedures such as the hip 
replacement are facilitated. 
In another aspect of the invention, a surgical table for receiving and 
positioning a patient is provided which comprises a chair and means for 
supporting the leg of a patient such that the leg assumes a predetermined 
position. The chair includes a backrest section having an upper back 
section and a lower back section. The lower back section includes a 
trough-shaped section which is adapted to receive the lower back of the 
patient, and an obliquely tapering pelvic support section which supports 
the pelvic section of the patient across the sacrum. A saddle-shaped 
member which extends upwardly and outwardly from the tapered end of the 
obliquely tapering pelvic section is attached to the pelvic support 
section and adapted to receive the perineum of the patient. The 
saddle-shaped member functions as a means for shoring the patient in the 
chair. 
Additional objects, advantages and novel features of the invention will be 
set forth in part in the description which follows, and in part will 
become apparent to those skilled in the art upon examination of the 
following, or may be learned by practice of the invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS 
Referring specifically to FIGS. 1-3, wherein like reference numerals are 
used to represent like elements, a surgical table 10 includes a chair 12, 
a frame 14 for supporting the chair at a predetermined elevation, and a 
leg support structure 16. 
The chair 12 includes a generally trough-shaped backrest 18 which is 
adapted to receive the upper torso portion of a patient. The backrest 
section 18 includes two wing-like members 24 which project upwardly and 
outwardly from the center of the backrest section 18. The projecting 
members 24 extend from the lower back to the ileac crest (loin) of the 
patient. The chair 12 also includes a convex section 23 in the backrest 18 
which accommodates the lordotic curve of the patient's back. 
The chair further includes a pelvic support section 20 which is preferably 
formed as an integral part of the chair. The pelvic support section 20 
mates with the backrest 18 of the chair 12 and tapers obliquely to the 
perineum or crotch area of the patient. The pelvic support section 20 
supports and positions the pelvic area including the pelvic bones 21 of a 
patient. The pelvic support section 20 is specifically configured such 
that the support does not underlie at least one preselected hip joint of 
the pelvic section 21 on which a medical procedure is to be performed. The 
preselected hip joint thus overhangs the edge of the pelvic support 
section 20 thereby providing an unobstructed x-ray path through the hip 
joint on which the surgical procedure is to be performed. Even though the 
chair 12 is configured to provide an unobstructed x-ray path through the 
hip joint of a patient, the chair is preferably made of x-ray transparent 
material such as surgical fiberglass to minimize x-ray interference from 
the chair. 
The chair 12 further includes a saddle-shaped section 22 which is attached 
to the tapered end of the pelvic support section 20. The saddle-shaped 
support structure 22 extends upwardly and outwardly from the end of the 
pelvic support section 20 (away from the perineum of the patient). The 
saddle-shaped structure 22 functions to shore or prop the patient in the 
chair 12. 
The chair support structure 14 includes an arm 28 from which the chair 12 
is pivotally supported by a pivoting element 26. Preferably the arm 28 is 
supported by vertical support columns 30 at an angle greater than 
0.degree. and preferably at an angle of about 42.degree. relative to a 
horizontal plane. In the illustrated preferred embodiment, the pivoting 
element 26 is disposed at the end of arm 28 proximate the lower back of 
the patient. The vertical support columns 30 are attached to a 
longitudinal horizontal support member 32 which is in turn attached to two 
orthogonal support members 34. The orthogonal support members 34 are 
disposed such that one is at each end of the horizontal support member 32. 
The vertical columns 30 support the chair 12 at a predetermined elevation 
thereby providing an unobstructed clearance of a predetermined height 
under the pelvic area of the patient. 
In a preferred embodiment the surgical table of the present invention 
further includes a C-arm x-ray device 42. In this embodiment the 
unobstructed clearance under the chair 12 is of a height such that an 
image intensifier member 40 of the C-arm x-ray device 42 may be freely 
rotated through a predetermined angle of swing under the pelvic section of 
the chair 12. The preferred height of the pelvic area accommodates 
rotation of the intensifier member 40 such that x-ray monitoring may be 
performed between 45.degree. caudal to 45.degree. cephalic when the axis 
of swing is through the femoral neck. A suitable C-arm x-ray device is 
commercially available from Orthopedic Equipment Company (OEC) of Salt 
Lake City, Utah. 
The leg support structure 16 is braced from a vertical support column 36 
which is attached to the horizontal members 32 and 34. A stiffener 38 is 
attached to the vertical support column 36 and the longitudinal horizontal 
member 32 to provide a rigid structure. The leg support structure 16 
includes a trough-shaped calf support member 44, and means for adjusting 
the height and position of the calf support member 44 such that the thigh 
bone 45 of a patient is positioned in a predetermined degree of flexion 
and abduction. Preferably, pneumatic bags are included in the trough 44 
for the patient's comfort. A crank 46 which is secured from a horizontally 
extending support member 48 functions to adjust the height of the calf 
support trough 44. A shoe-like member 50, which is attached to a vertical 
support member 52, is used to secure the patient's leg in the selected 
degree of abduction and flexion. A locking hinge 51 is used to adjust the 
rotation of the shoe support member 52 about its vertical axis and thus to 
lock the patient's foot in the proper degree of abduction. 
A second shoe-like member 54 may be included to support the other leg of 
the patient for the patient's comfort. Preferably, the second shoe-like 
foot support 54 is disposed such that it positions the foot secured by 
this member at a lower elevation than the foot supported by the first 
shoe-like support 50. It is further preferred that the shoe-like support 
54 position the patient's leg is in a substantially horizontal position. 
Although the present preferred embodiment has been described with reference 
to positioning the thigh of a patient in a preferred degree of abduction, 
it will be recognized by those skilled in the art that the present 
invention also contemplates securing a patient's leg in a predetermined 
degree of adduction. 
The surgical table 10 preferably also includes a means for adjusting the 
pitch and roll of the chair 12. Pitch here is defined as the inclination 
of the chair about an axis which is orthogonal to the longitudinal axis of 
the chair 12 and to an axis orthogonal to a vertical plane. Roll is 
defined here as a rotation about the longitudinal axis or the chair. The 
adjusting means includes two cranks 56 and 57 arranged such that one crank 
is disposed on each side of the chair 12. The cranks 56 and 57 are 
disposed beneath the chair 12 such that each extends upwardly and abuts 
against a crank support member 58. The crank support member 58 preferably 
includes handles 59 (only one shown) which may be used to manually rotate 
the chair 12 about its pitch axis. 
FIG. 4 shows another preferred embodiment of the present invention. A chair 
70 includes the saddle-like support member 62 which is adapted to fit 
between the perineum of the patient; a pelvic support member 60 which 
tapers obliquely to the perineum of the patient; a pair of wing-like 
elements 64 which extend outwardly from the chair; and a curved section in 
the lower back of the chair adapted to receive and curved for the lordotic 
section of the patient's back. In this embodiment however, the upper back 
portion 68 of the chair 60 does not have a trough shape or form, but 
rather includes a planar configuration. The lateral edges of the upper 
back portion 68 preferably extend beyond the shoulders of a patient. The 
back section may include cushioning for the comfort of the patient. 
The surgical table of the present invention provides several advantages 
over prior art devices. For purposes of illustration the embodiment of 
FIGS. 1-3 is used in the following description. In the embodiment shown in 
these figures, a patient may be positioned in the chair 12 by tilting the 
chair about its pitch axis to an upright position. In this manner a 
patient may walk on and sit in the chair thereby facilitating the 
procedure used to position a patient on the surgical table 10. The chair 
12 may then be reclined such that the patient is in the desired lying 
position. The patient maintains the desired position since the pitch of 
surgical table is preferably maintained at an angle greater than 
0.degree.. In this manner the weight of the patient causes him to slide 
downwardly in the chair 12. The saddle-shaped support member 22 limits the 
downward movement of the patient and thus functions to shore the patient 
in the predetermined position. Since the saddle-shaped member 22 is 
inclined upwardly and outwardly, the patient does not experience the 
discomfort associated with post-type supports. The saddle-shaped support 
member 22 also has psychological advantages. The saddle-shaped member 22 
does not have the uncomfortable appearance of a post and yet the patient 
feels that he is secured by the saddle-shaped support 22 from either 
sliding down or falling to either side of the chair 12. The wing-like 
projecting members 24 prevent the patient's torso from falling off of the 
edge of the chair 12 when the patient rolls or is turned. 
The contour shape of the chair accommodates the patient's body thereby 
providing a comfortable setting for the patient. Since the pelvic support 
section 20 of the chair 12 obliquely tapers such that it does not underlie 
the selected hip joint of the patient, the selected hip joint overhangs 
the edge of the pelvic section 20. In this manner the chair 12 comfortably 
supports the patient's pelvic section while not interfering with an x-ray 
path through the hip joint. 
The leg support structure 16 may be used to position the patient in an 
atavistic (or other predetermined) position. As discussed above, in the 
atavistic position the femoral head is completely within the acetabulum. 
The preferable position of the leg such that the thigh assumes the desired 
atavistic position is when the thigh has 80.degree. flexion and 10.degree. 
abduction. To position the leg of the patient, the leg support structure 
16 is first adjusted to place the patient's thigh in the desired degree of 
flexion and abduction. The upper-chair cranks 56, 57 and crank support 
structure 58 may then be used to fine tune the adjustment of the patient's 
position. The cranks 56 and 57 may be synchronously adjusted such that the 
pitch of the chair 12 is adjusted. Alternatively the cranks 56 and 57 may 
be adjusted independently to adjust the roll of the chair 12. In this 
manner with use of the C-arm device 42, the patient may be positioned in 
the desired atavistic position. 
The trough-shaped calf support member 44 is designed such that the calf of 
the patient will fit comfortably within the structure while maintaining 
the patient's leg in a secured position. The shoe-like foot support 
structure 50 is made to secure the foot of the patient such that the 
position of the patient's leg will be fixed The second shoe-like foot 
structure 54 maintains the other leg of the patient in a secured position 
substantially parallel to the patient's body and is primarily used for the 
comfort of the patient 
As illustrated in the figures, the chair support structure 14 is arranged 
such that it does not interfere with the rotation of the C-arm 43. The 
intensifier 40 is accommodated beneath the arm 28 of the support structure 
14. The C-arm 43 may be rotated between 45.degree. caudal to 45.degree. 
cephalic when the axis of swing is through the femoral neck, thereby 
accommodating the antiversion. This allows the physician to determine 
precisely where the center of the femoral neck is located, thereby 
simplifying the surgical procedure. 
Although the present invention has been described with reference to the 
advantages obtained for surgical procedures such as the method described 
in the Fischer patent of installing a prosthesis, it will be readily 
apparent to those skilled in the art that the surgical table of the 
present invention may be used for other applications such as core 
drilling, grafting, or Girdlestone. The surgical table may also be used 
without the C-arm device for procedures such as removing previously 
inserted pins or nails in the patient's leg. 
The surgical table of the present invention thus provides a table in which 
the patient may be positioned in from a walk on position and adjusts to a 
contour resting position The surgical table provides several advantages 
over existing tables which incorporate slabs or posts. The surgical table 
provides a comfortable surgical environment for a patient while 
maintaining the patient in a preferred surgical posture. The table of the 
present invention provides for three-dimensional fixed positioning of the 
femur relative to the hip joint acetabulum. The apparatus provides 
positioning for the hip and the thigh in a predetermined degree of flexion 
combined with linear transverse positioning for the hip and knee 
abduction. The posture of the patient may be adjusted in the fixed 
position and secured in this position thereby facilitating surgical 
procedures. 
The foregoing description of the preferred embodiments of the present 
invention has been presented for purposes of illustration and description. 
It is neither intended to be exhaustive or to limit the invention to the 
precise forms disclosed. Obviously many modifications and variations are 
possible in light of the above teachings. It is therefore intended that 
the scope of the invention be defined by the following claims, including 
all equivalents.