Patent Publication Number: US-10782181-B2

Title: Radiograph stand with weigh scale

Description:
CROSS REFERENCE OF RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Application No. 62/481,735, filed on 5 Apr. 2017, and U.S. Provisional Application No. 62/633,689, filed on 22 Feb. 2018, which are hereby incorporated by reference. 
    
    
     STATEMENT OF FEDERAL SPONSORED RESEARCH 
     This invention was made with government support from the Defense Medical Research and Development Program (Department of the Navy). The government has certain rights in the invention. 
    
    
     FIELD OF INVENTION 
     This invention relates to a new and improved radiograph equipment, useful for obtaining weight-bearing orthopedic radiographs. 
     BACKGROUND 
     Traumatic orthopedic injuries are best evaluated with weight-bearing radiographs, such as x-rays. For example, although rotational ankle fractures contain a combination of bony and ligamentous injuries, only those injuries that are unstable require surgery. While the bony injuries are evident on x-rays, the integrity of medial ligamentous structures can be more fully evaluated using stress radiographs. Weight-bearing x-rays are one way to stress the ligaments, which can be used to determine if surgery is required (1-3). Similarly, isolated injuries to the ligaments of the syndesmosis, and the midfoot are best evaluated on weight-bearing radiographs (4, 5). In these injuries, the sprains are first graded based on imaging findings, and surgical indications are then determined. 
     A weight-bearing radiograph is also beneficial in the analysis and diagnosis of various orthopedic deformities. In hallux valgus, radiographic measurements including the hallux valgus angle, intermetatarsal angle, and sesamoid position are taken using weight-bearing x-rays. Physicians use these variables along with clinical symptoms to determine the appropriate treatment strategy (6, 7). Similarly, the severity of acquired adult flatfoot deformity (AAFD) can be more accurately graded using weight-bearing x-rays. Meary&#39;s line is critical in evaluation of AAFD. It measures the colinearity of the talus, midfoot, and forefoot, which is evaluated using weight-bearing x-rays (8, 9). Instability of the subtalar joint is also only detectable through weight-bearing radiography (10). 
     In addition to orthopedic injuries and deformities, weight-bearing radiography also benefits the diagnosis and treatment of chronic joint disease, such as arthritis. Arthritis is characterized by the loss of cartilage that normally fills the joint spaces throughout the body. Since cartilage is radiolucent, the loss of cartilage cannot be directly measured. Instead it is evaluated by measuring the space between bones while weight is applied to compress the joint surfaces together. Without reliable weight-bearing x-rays, arthritis of the foot and ankle cannot be fully evaluated (11, 12). 
     The functional position of the knee, hip, and spine is one of upright weight-bearing. Weight-bearing x-rays of the knee improve the evaluation of osteoarthritis (14), allow for an accurate assessment of alignment, and can provide more useful clinical information than an magnetic imaging resonance (MRI) in patients older than 40 (13). Osteoarthritis and developmental dysplasia of the hip can be more accurately staged using weight-bearing x-rays (15). 
     The usefulness of weight-bearing x-rays have been demonstrated across the orthopedic, sports medicine, rheumatology, and radiology literature for a number of disease processes of the lower extremities. It has been proposed as an alternative, inexpensive and superior physiologic test to guide early decision-making about for ankle stability (Hoshino et al., 2012), even over MRI. While MRI is capable of providing a lot of information, such as bone bruise patterns, osteochondral lesions, and tendon injuries, it is not ideal for acute ankle fracture diagnosis. It is both expensive and time-consuming. The clinical implications of the surplus of MRI findings can lead to unnecessary surgical procedures. In comparison, weight-bearing x-rays offer a quick, inexpensive test that is familiar to most clinicians. Many doctors are trained to interpret the x-ray without the assistance of a radiologist. Additionally, weight-bearing radiograph can directly simulate forces that a patient will be placing on the joint during the period of fracture and ligament healing. 
     Although useful for assessment of orthopedic injury, disease and joint deformities, a major challenge remains in taking weight-bearing radiograph, which may affect the quality of a resulting radiograph, and possibly leads to misdiagnosis. Most patients with a bone or joint problem are suffering from some level of pain, making it difficult to place their full weight onto the affected limb. For example, a patient who suffers foot or ankle injury often would slightly lift their injured foot or shift their weight to the healthy side while taking a weight-bearing radiograph in fear of further damaging the injured limb or to simply to avoid pain. Because radiograph is a record of shadows produced by objects of varying opacity to radiation on the sensitive film surface, inadequate weight placement during weight-bearing radiographs can result in images that do not accurately represent the position of the bones and ligaments. Any change in the angular position or spread position of the feet produces corresponding position changes in the bones, which distort the resulting photographs, and destroy the comparative value of the various views being taken. It is therefore extremely important that a patient remain in his/her required stance during weight-bearing x-rays so that the appropriate weight is placed on the limbs. It was revealed in one study that even healthy volunteers without pain were only able to evenly distribute their weight (within 10%) 48% of the time (16). This finding is more concerning as a clinician is routinely making medical decisions under the assumption of appropriate weight-bearing, but has no objective means of testing this. No device is currently available to allow a radiograph technician or a physician to verify the weight being born by the affected limb at the time of the x-ray. The present invention discloses an x-ray equipment that solves this problem, which comprises a stand, with a weigh scale designed for measuring the weight placed by patient while taking a weight-bearing radiograph of the foot, ankle, hip and other joints. 
     SUMMARY OF INVENTION 
     It is an objective of the present invention to provide new and improved radiographic equipment for taking weight-bearing radiographs of the lower extremity (legs, foot, knee, hip etc.) of a patient. The inventive radiographic equipment can simultaneously record the weight that is placed on the limbs by a patient during a weight-bearing x-ray. According to the presents invention, weight-bearing dorsi-plantar, medial oblique and lateral radiographs may be taken with the patient standing in his/her normal base stance, while the weight placed on the injured limb or joint is simultaneously measured and recorded. 
     Another objective of the present invention is to provide a new and improved method for taking a weight-bearing radiograph of a patient&#39;s foot, ankle and other joints, wherein the weight placed on the patient&#39;s limb or joint during comparative x-rays are simultaneously measured and recorded to aid later medical analysis, diagnosis and treatment. For example, a weight-bearing radiograph of an injured limb or joint may be compared to a non-weight-bearing radiograph of the same limb or joint to ensure a true stressed x-ray, which would result in a more accurate assessment of the injury. 
     Another objective of the present invention is to provide a new and improved radiographic apparatus, which allows comparative weight-bearing x-rays of a patient&#39;s foot, ankle and other joints be taken while recording the weights that a patient placed on different limbs/joints or while the patient is standing in different postures. 
     Yet another objective of the present invention is a new and improved radiographic apparatus with weigh scales that may be triggered by audio or visual cutes during a weight-bearing radiograph. 
    
    
     
       DETAILED DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a weight-bearing radiography system of this invention, comprising an x-ray stand with an integrated weigh scale according to one embodiment. 
         FIG. 2  is a perspective view of an embodiment of the presented invention, which is x-ray stand with integrated weigh scales (A) and its cross-sectional view (B). 
         FIG. 3  shows a perspective view of an embodiment of the present invention, wherein the weight-bearing x-ray stand is a cassette protector with an integrated weigh scale (A) a top view (B) and a cross-sectional view (C) of the same embodiment. 
         FIG. 4  shows the top view of an embodiment of the present invention, wherein the x-ray stand has double weigh scales with mechanical display (A) and a top view of the same embodiment (B). 
         FIG. 5  shows another embodiment of the present invention, wherein x-ray stand is a balance board with four weigh areas. 
         FIG. 6  illustrates how comparative weight-bearing x-rays of both knees may be simultaneously taken. 
         FIG. 7  shows how to take weight-bearing AP view of a patient&#39;s knee using a weigh scale board of this invention. 
         FIG. 8  shows how to take weight-bearing x-ray of patient knee can be taken while the patient takes a forward lunge. 
         FIG. 9  shows a top view of an embodiment of the inventive device being used in taking AP and oblique x-rays of the foot while placed under the x-ray cassette and cassette protector (A) and a side of view of an embodiment of the inventive device being used in taking AP and oblique x-rays of the foot while placed under the x-ray cassette and cassette protector. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     It is to be noted that the term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more,” and “at least one” can be used interchangeably herein. 
     Furthermore, “and/or” where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. Thus, the term “and/or” as used in a phrase such as “A and/or B” herein is intended to include “A and B,” “A or B,” “A” (alone), and “B” (alone). Likewise, the term “and/or” as used in a phrase such as “A, B, and/or C” is intended to encompass each of the following aspects: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); and C (alone). 
     It is understood that wherever aspects are described herein with the language “comprising,” otherwise analogous aspects described in terms of “consisting of” and/or “consisting essentially of” are also provided. 
     A radiograph is defined as an image produced on a sensitive plate or film by x-rays, gamma rays, or similar radiation, and typically used in medical examination 
     A limb is defined a part or member of the human body distinct from the head and trunk, such as a leg, arm, or a foot. 
     A radiograph cassette is defined as an image receptor, which includes but is not limited to a container used to hold radiographic film, storage phosphor plate, a charge coupled device, thin-film transistors, photoconductor, or x-ray scintillator. 
     The above and other objects and advantages of the present invention will be more apparent from the following detailed description of the preferred embodiments when read in connection with the accompanied drawings, where in like reference numerals designate like or corresponding parts throughout the figures: 
     As shown in  FIG. 1 , a radiograph system  10  according this invention comprises of an x-ray radiator  11  operatively connected to a radiographic equipment  12 . The x-ray radiator  11  further comprises of an x-ray source  13 , an x-ray source controller  15  and an activator switch  17 . An x-ray source  13  typically has an x-ray tube for radiating x-rays, and a collimator for limiting the irradiation field of x-rays  18  from the x-ray tube. The radiographic equipment  12  according to this invention may comprises an electronic cassette  14  for capturing radiography, an image acquisition controller  23 , a weigh scale  16  and a console  24 . The electronic cassette  14  mainly comprises of a flat panel detector (FPD)  26 , which functions as a radiographic image detector and a housing  27  that contains the FPD  26 . The electronic cassette  14  is a portable x-ray image detector that receives x-rays from the x-ray source  13  after they penetrating through a limb or joint of a patient  19 , thus producing an x-ray image (radiograph) of that limb or joint  19 . The electronic cassette  14  is provided with a communicator  29  for communication with the console  24 , and a memory  28  for storing a cassette ID. The cassette ID  20  is information necessary for the console  24  to identify each individual cassette  14  among many cassettes communicably connected to the console  24 . An example of the console is a computer or a device equipped with a microprocessor. The cassette ID  20  is attached to communication data that is exchanged between the console  24  and each cassette  14  so the communication data can be linked to the patient who is taking the x-ray. This data communication may be accomplished via wire or wireless communication. 
     In the present invention, one or more weigh scale  16  may be incorporated into a radiograph stand as shown in  FIG. 2A-B , or incorporated into a radiograph cassette protector as shown in  FIG. 3A-C  or acting as a stand-alone unit capable of measuring weight measurements while taking weight-bearing radiograph, as shown in  FIG. 9 . Using the weigh scale of the present invention, weight a patient placed on one or both legs/foots/joints during a weight-bearing x-ray can be measured and recorded. The weight measurements can be either displayed directly on the weighing apparatus, such as on display screen of the weigh scale as in  FIG. 4 , or be separately measured, recorded, communicated and displayed by a console as shown in  FIG. 1 . The weight measuring mechanism of the weigh scale  16  can be either electronic or mechanical. They are housed in the radiopaque part of the radiograph cassette protector or radiograph stand. Such electronic and mechanical weight measuring mechanism are well-known in the art, and can be easily adapted for the present invention. Some examples are described in U.S. Pat. Nos. 4,219,092, 6,700,080, 4,336,3368, etc. 
     The weigh scale  16  may further comprises a triggering mechanism, which is communicatively connected to the activator switch  17 , the image acquisition controller  23 , and/or the console  24 . Examples of a triggering mechanism are described in U.S. Pat. No. 4,387,722, or U.S. Pat. No. 5,887,049, which can be easily adapted for this invention. When triggering mechanisms are activated, the weight a patient placed on selected weigh scales are measured, while x-rays of the patient&#39;s leg/foot/joint are simultaneously taken. The triggering mechanism may also comprises an audio or visual sensor, which triggers the radiographic system of the present invention to take the weight measurements and x-ray simultaneously in response to an auditory or visual cue. For example, an audio trigger may be a sound generated by an x-ray machine or the technician. Commercial x-ray machines are normally equipped with a safety buzzer that is sounded when the x-ray tube is active and emitting radiation. This buzzer sound can be detected by an audio sensor and programmed to trigger the weigh scale/x-ray so that weight measurements are taken and recorded when an x-ray is taken. There are several types of audio activated triggering mechanisms known in the art, which may be adapted for this invention. An example of a simple audio-actuated switch is described in U.S. Pat. No. 3,582,671. The audio-actuated switch of Patent &#39;671 includes a thyristor, preferably an SCR, the gate of which is triggered by an audio frequency signal from a microphone and audio amplifier. The amplifier is a class A audio amplifier with biasing and loading provided so that a light will be activated by sound above a selected level. A nonlinear potentiometer is used for the load impedance of one of the amplifier stages to permit selection of the desired audio level which triggers the thyristor. The input terminals of a rectified power supply are connected across the principal terminals of the SCR so that the parallel combination may be connected in series with the electric light and an alternating current power source. A signal process circuit may also be connected a microphone and used to identify the frequency and intensity of a pre-programmed sound signal. A speech activated triggering mechanism may also be used in the present invention. One of such triggering system is described in US20090138507, which employs speech emanating from the user as the triggering event. 
     The weight scale of the present invention may also be triggered by a pre-programmed weight ratio between selected weigh scales. For example, during a comparative weight-bearing x-ray, when weights placed a patient on different weigh scale reaches a target ratio, the triggering mechanism  47  sends signals to the activator switch  17 , the image acquisition controller  23  and/or the console  24 , allowing the weights placed on the different weigh scales during a comparative weight-bearing radiograph be simultaneously measured and recorded. This ensures that a true stressed x-ray of the patient&#39;s injured leg/foot/joint. 
     An embodiment of a radiograph stand of the present invention is shown in  FIGS. 2A and 2B , wherein weigh scales are incorporated into the radiograph stand platform.  FIG. 2A  shows a weight bearing x-ray platform  45 , with one or more receptor slot or holder  44  on top of the platform allowing vertical placement of electronic cassette  14  for taking lateral radiograph of the foot and ankle. One or more cavities  35  are provided under the platform  45  for insertion of an electronic cassette  14  when taking dorsi-plantar, medial oblique radiograph of the foot and ankle. Each electronic cassette cavities  35  is covered by a radiolucent plate  38  with the plane size slightly larger than the surface of radiographic cassette  14 . The radiolucent plate  38  is operatively connected to one or more weight sensors  39  ( FIG. 2B ), allowing weight of placed on the radiolucent plate  38  to be measured, recorded, and shown on a display  42 , and/or communicated to a console  24 . Alternatively, the platform contains no cassette cavities, but is partially covered by a radiolucent plate  38  with the plane size slightly larger than the surface of radiographic cassette  14 , which is operatively connected to one or more weight sensors  39  housed in radiopaque region  32  of the platform. A radiographic cassette  14  is directly placed on the floor underneath the radiolucent plate  38 , while the weight-bearing x-ray is taken. The weight of placed on the radiolucent plate  38  is then measured, recorded, shown on a weight display  42  and/or communicated to a console  24 . The weight bearing x-ray platform  45  may also include a handle  46  for the patient to hold on to so the patient can stand as close to their normal stance as possible without losing balance. The radiopaque region  32  ( FIG. 2A  and  FIG. 2B ), which may be the frame enclosing the radiolucent region, houses the mechanical and/or electronic components of the weigh scale  16 , such as weight display  42 , weight sensors  39 , memory  40  and communicator  41 . 
     In  FIG. 3A-C , a different embodiment of the weight-bearing radiograph stand of the present invention is shown as a radiograph cassette protector  30 . The radiograph cassette protector  30  has a flat planner body having substantially rectangular top surface  33  and bottom surface  34 , and at least two opposing side panels  36  or  37 , forming an interior cavity  31 . The interior cavity  31  is separated into a radiolucent region  35 , and a radiopaque region  32 . The radiolucent region  35  has a plane size slightly larger than the size of a radiographic cassette  14 , and creating a cavity adapted for the insertion of a radiographic cassette  14 . The radiopaque region  32 , which may be the frame that is encasing the radiolucent region  35 , houses the mechanical and/or electronic components of the weigh scale  16 , such as weight display  42 , weight sensors  39 , memory  40  and communicator  41 . 
     As shown in  FIG. 3C , the radiolucent region  35  is covered with a radiolucent plate  38 , which is operatively connected with the weigh sensors  39  housed in the radiopaque frame  32  of the weight-bearing radiograph cassette protector  30 . The other electronic/mechanical component of the weigh scale  16 , may include weight display  42 , memory  40  and communicator  41 . As shown in  FIG. 3B , the weight-bearing radiograph cassette protector  30  of  FIG. 2A , may further comprise one or more receptor slot  44  or holder  43  on top or on the side, allowing vertical placement of electronic cassette  14  for taking lateral radiograph of the foot and ankle. 
       FIG. 4A-B  shows the top view of the platform surface of a weight-bearing x-ray stand of the present invention.  FIG. 4A  illustrates a weight-bearing x-ray stand with double weigh scales, which are capable of measuring weights a patient placed on both leg/foot/knee during a weight-bearing x-ray. Each weigh scale may further contain locking mechanisms that can disable the operation of a weigh scale when only the weight of one foot is needed.  FIG. 4B  shows an alternative embodiment of  FIG. 4A , which contains only a single weigh scale. In both embodiments, the weigh scale may be electronic or mechanical. Alternatively, the weight-bearing x-ray stand of the present invention may also include up to four weigh scales, allowing comparative weight-bearing x-rays be taken between different leg/foot/joint or at different postures. 
       FIG. 5A  shows yet another embodiment of the present invention, comprising a weigh scale board  50  similar to a Wii Fit balance Board. A weight scale board  50  for taking weight-bearing x-ray of the foot, leg, knee or other joint, comprising: a base unit  53 , said base unit configured in size and shape to securely and stably hold one or more weight sensing platform  51 A-D; at least one anchor point  58  disposed on said base in a vicinity of a terminal end of said weight sensing platform  51 A-D; and a resistance mechanism  57  attached at a first end by a fastener (not shown) to said anchor point such that when a user positioned on said balance and weight sensing platform  51 A-D exerts a force on a holding loop (not shown) attached to a second end of said resistance mechanism  57  said balance and weight sensing platform senses said exerted force and said balance and weight sensing platform senses an apparent shift in a center of balance occasioned by said exerted force. The weigh sensing platform  51 A-D may further comprising a radiolucent plate  55  and a radiopaque housing  56 . An x-ray cassette receptor  52  may be provided directly below each radiolucent plate  55  sized and adapted to receive an x-ray cassette. The weight resistance mechanism, the fasteners and the anchor point are all provided within said radiopaque housing. 
     The weigh scale board  50  contains up to four weight sensing platform areas  51 A-D. Each weight sensing platform areas area  51 A-D can be used as an individual weigh scale or used in combination. The weigh scale board  50  is communicatively connected to a weight sensing platform area selector (not shown), which is communicatively connected to the triggering mechanism  47  and/or the console  24 . The communication may be conducted by wire  54  or wireless connections. Weight sensing platform area selector allows the technician to select the weight sensing platform areas  51 A-D to be used in an x-ray, and communicate that selection to the console. The weight a patient placed on the selected weight sensing platform areas  51  during a weight-bearing x-ray are then measured and recorded. A weigh measuring mechanism  56  is housed underneath weight sensing platform areas within the radiopaque housing  56 . The weigh measuring mechanism may be electrical or mechanical and are both well taught in the art. An example of a weigh measuring mechanism that can be used for this embodiment, is described in US20110218077 (Juan Fernandez), and is hereby incorporated in this invention. An alternative weigh measuring mechanism may be plurality strain gauge sensors and software similar to which used in a Wii balance board (as described in Appendix A and hereby incorporated by reference). It is understood that many other weigh measuring mechanisms may be used in the weigh scale board of this invention, and is not limited to the examples, figures and descriptions of this application. 
     Comparative x-rays of different leg/foot/joint may be taken simultaneously while the patient places each foot in a different weight sensing platform areas  51 . The triggering mechanism  47  may trigger the activator switch  17  when a target weight ratio is reached between the selected weight sensing platform areas. X-rays of limbs positioned on those selected weight sensing platform areas are automatically activated and taken. In an alternative embodiment, the weights that a patient placed on the selected weight sensing platform areas  51  are measured when the weigh measuring mechanism is activated by a buzzer sound of an x-ray machine or the voice of a technician. Weight scale board may also comprises a light sensor. When x-ray is activated, the light sensor triggers the weight scales, and allow weight measurements placed selected weight sensing platform areas  51 A-D to be taken and recorded. The total weight placed on all selected weigh area may be also measured and recorded. 
     In yet another embodiment as shown in  FIGS. 9  A and B, the weigh scale  16  or weigh scale board  50  may be used as a stand-alone unit. The top surface of the weigh scale  16 /weigh scale board  50 , comprises three separate weight sensing platform areas  51 , which is marked with lines  57  to aid the technician to properly position the patient&#39;s feet on the scale. The weigh scale  16 /weigh scale board  50  may further comprises one or more weight displays  42 , which provide readout of the weight placed on the left foot (left display), the right foot (right display) and/or the total weight (center display). In situation where the weigh scale  16  is in the direct path of the x-ray beam, such as for AP and oblique views of the foot, the radiograph cassette  14  and cassette protector  30  is placed on top of the stand-alone weigh scale  16 /weigh scale board  50 . 
     Example 1: Operation of the Weight-Bearing X-Ray Stand in Taking Radiograph of the Patient&#39;s Foot or Ankle 
     To use the inventive x-ray stand to take a lateral radiograph of the patient&#39;s foot or ankle:
         a) Let the patient stand in his or her normal base stance with the foot firmly positioned on the x-ray stand platform or the cassette protector;   b) Make sure the foot that is being x-rayed is planted on a radiolucent plate of the weigh scale with the lower leg perpendicular to the floor or weight-bearing X-ray stand surface;   c) An electronic cassette is then placed in slot or a vertical x-ray film holder, next to the injured feet which allows a radiograph cassette to be held parallel to the patient&#39;s foot axis for lateral x-ray to be taken;   d) The central beam is directed through the foot perpendicular to the axis of the foot, and the detector;   e) The x-ray and the weigh scale is activated;   f) The weight placed on the injured foot during x-ray is measured and recorded; and   g) A non-weight bearing x-ray of the injured feet or an X-ray of the patient&#39;s healthy foot may be taken with weight placed on each foot recorded for comparison.       

     To use the inventive x-ray stand to take a weight-bearing dorsoplantar foot/ankle radiograph of the patient&#39;s foot or ankle:
         a) Let the patient stand in his or her normal base stance with the foot firmly positioned on the x-ray stand platform or the cassette protector;   b) Make sure the foot being X-rayed is planted on the cassette protector or platform&#39;s radiolucent plate with the lower leg perpendicular to the floor or weight-bearing surface;   c) A radiographic cassette is inserted in the cassette cavity;   d) The central beam is angled approximately 15 degrees towards the heel to minimize projecting the tibia and fibula over the hind foot;   e) The x-ray and the weigh scale is activated;   f) The weight-bearing, non-weight-bearing radiographs of the injured foot and radiograph of the healthy foot during normal stance may then be taken for later comparison; and   g) Weight placed on each foot during radiograph is measured, recorded, displayed and or communicated to the console.       

     Example 2: Operation of the Weight-Bearing X-Ray Stand in Taking Radiograph of the Patient&#39;s Knee 
     The knee is a weight bearing joint and therefore for all intents and purposes, knee x-rays should be taken while weight bearing. As radiographs are a two-dimensional representation of a three-dimensional bony structure, radiographs of the knee are normally taken in two planes at right angles to each other to infer all three dimensions. For example, a radiograph may show a complete loss of medial (inner) joint space, which was not evident on the standing anteroposterior (AP, front-back) x-ray. The 45° flexed PA standing view of the knee is a much more sensitive x-ray in showing early degenerative disease in the position of function. For example, the 45° flexed PA standing view of the knee provides an accurate definition of the width of the intercondylar notch, which is very useful information for patients undergoing ACL reconstruction. The standing AP x-ray will give an indication of the presence of degenerative disease within the knee. Standing AP is also an indication of the alignment of the knee joint. The width of the intercondylar notch gives indication of the size of the contents of the notch, which are the anterior and posterior cruciate ligaments. 60% of the notch is occupied by the PCL, 40% by the ACL approximately. The patients with a narrow notch are more likely to tear their ACL&#39;s as this is an indication of a small anterior cruciate ligament. Measuring the size of the notch on the x-ray allows the surgeon to plan the degree of notchplasty that is required. In certain situations, it can also help the surgeon to decide whether to use an ipsilateral or contralateral patella tendon graft for the ACL reconstruction. As people do not walk with their knees fully extended, but tend to have their knees flexed during the gait cycle, a flexed x-ray view brings the weight bearing part of the knee joint into the view on the radiograph. All these views will also show fractures about the knee and may give information to direct further imaging studies. 
       FIG. 6  shows how a knee AP weight-bearing view is taken using a weigh scale board of this invention:
         a) The patient is erect on a weigh scale board or stand of this invention against the upright detector with each foot standing in two weigh scale areas ( FIG. 5   51 AB or  FIG. 5   51 CD);   b) make sure that patient&#39;s knee is flexed at approximately 45° with grid in front of knees;   c) ensure patient&#39;s knee is not rotated;   d) direct beam approximately 10° caudal from the horizontal plane through the knee joint   e) activate the x-ray either manually, via audio and/or visual signal or automatically when a preset target weight ratio between the two weigh scale areas is achieved   f) weight placed on each foot during radiograph is measured, recorded, displayed and or communicated to the console   g) Each x-ray is associated with the cassette ID and weight measured.       

       FIG. 7  shows how to take weight bearing AP view of a patient&#39;s knee using a weigh scale board of this invention:
         a) The patient is erect on a weigh scale board in upright position with back toward vertical grid device on the upright detector with each foot standing in two weigh scale areas   b) Make sure the patient&#39;s toes straight ahead, with feet separated enough for good balance.   c) Ask patient to stand straight with knees fully extended and weight equally distributed on feet.   d) Place central ray Horizontal and perpendicular to center of IR, entering at point 1.3 cm below apices of patellae.   e) activate the x-ray either manually, via audio and/or visual signal or automatically when a preset target weight ratio between the two weigh scale areas is achieved   f) weight placed on each foot during radiograph is measured, recorded, displayed and or communicated to the console   g) each x-ray is associated with the cassette ID, weight measured       

     Example 3: Operation of the Weight-Bearing X-Ray Stand in Taking Radiograph of the Patient&#39;s Knee in Different Position 
       FIG. 8  shows how to take weight-bearing X-ray of patient knee can be taken when the patient takes a slight forward lunge
         a) The patient is stand on a weigh scale board face toward vertical grid device on the upright detector   b) Asking the patient to take a step forward into a slight lunge, so the patient&#39;s two feet are standing in two different weigh scale area   c) Make sure the patient&#39;s toes straight ahead, with feet separated enough for good balance, and weight equally distributed on feet.   d) Place central ray parallel to the joint surface of the tibial plateau   e) activate the x-ray either manually, via audio and/or visual signal or automatically when a preset target weight ratio between the two weigh scale areas is achieved   f) weight placed on each foot during radiograph is measured, recorded, displayed and or communicated to the console   g) each x-ray is associated with the cassette ID and weight measured       

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         8—Orthop Traumatol Surg Res. 2015 February; 101(1 Suppl):S11-7. doi: 10.1016/j.otsr.2014.07.030. Epub 2015 Jan. 13. Adult flatfoot. Toullec E1. 
         9—J Bone Joint Surg Am. 2014 Apr. 16; 96(8):e63. doi: 10.2106/JBJS.L.01205. Comparison of deformity with respect to the talus in patients with posterior tibial tendon dysfunction and controls using multiplanarweight-bearing imaging or conventional radiography. Haleem AM1, Pavlov H1, Bogner E1, Sofka Cl, Deland JTI, Ellis SJ1. 
         10—Subtalar joint instability. Mittlmeier T, Wichelhaus A. Eur J Trauma Emerg Surg. 2015 December; 41(6):623-9. doi: 10.1007/s00068-015-0588-7. Epub 2015 Oct. 28. Review. 
         11—Weight-bearing-line analysis in supramalleolar osteotomy for  varus -type osteoarthritis of the ankle. Haraguchi N, Ota K, Tsunoda N, Seike K, Kanetake Y, Tsutaya A. J Bone Joint Surg Am. 2015 Feb. 18; 97(4):333-9. doi 
         12—Does the subtalar joint compensate for ankle malalignment in end-stage ankle arthritis?Wang B, Saltzman C L, Chalayon O, Barg A. Clin Orthop Relat Res. 2015 January; 473(1):318-25. doi: 10.1007/s11999-014-3960-8. Epub 2014 Oct. 15. 
         13—The Use of MRI in Evaluating Knee Pain in Patients Aged 40 Years and Older. Adelani M A, et al. J Am Acad Orthop Surg. 2016 September; 24(9):653-9 (Demonstrated that weight bearing xrays of the knee were more valuable than MRI in the evaluation of patients older than 40 years with knee pain) 
         14—The Combination of the Tunnel View and the Weight-Bearing Anteroposterior Radiographs Improve the Detection of Knee Arthritis. Babatunde, O M, et al. Arthritis. 2016:9786924 (Showed that the addition of the weight bearing tunnel view of the knee is valuable in the evaluation of knee arthritis) 
         15—Comparison of Pelvic Radiographs in Weightbearing and Supine Positions. Fuches-Winkelmann, et al. Clin Orthop Relat Res 2008 April; 466(4) 809-812 (Demonstrated the usefulness of weight bearing xrays in the evaluation of the acetabular roof obliquity and joint space width in the setting of hip dysplasia and osteoarthritis) 
         16—High Variability of Observed Weight Bearing During Standing Foot and Ankle Radiographs. Miller, et al. Foot Ankle Int 2017; Vol. 38(6).