A new day has arrived in the form of a technological breakthrough in diagnostic imaging which is uniquely capable of providing us with new insights essential to our management and veterinary care of sport horses. Until now, this diagnostic information has escaped our detection and yet it underlies many of the chronic lameness problems that impact performance and longevity in our horses’ athletic careers.
It will provide answers to many questions about the development of orthopedic lameness and poor performance in sport horses by enabling us to visualize, analyze and diagnose orthopedic stress and pathology in 3 dimensions in the naturally loaded limb.
It is a new 3D CT Scanner which produces the highest resolution 3D imaging studies in the standing horse. The development of this Equine Standing 3D CT Scanner began in 2013 as a project of my nonprofit 501(c)(3) organization Homecoming Farm, Inc. and its educational and research program, The American College of Veterinary Sports Medicine and Rehabilitation ®.
For the past two years I have worked with the manufacturer to design a game changing CT that is easy and economical to use, and extremely horse friendly.
In an ongoing quest to find ways to answer the most challenging questions related to the prevention and successful recovery of injury in sport horses I endeavor to keep current on advances made in the analogous human medical specialties. For twenty years I have asked physician colleagues at sports medicine and rehabilitation conferences if they had the ability to obtain high resolution imaging studies in the standing patient.
Each year the answer was the same- “No, but we wish we could have that too.” Then in 2012, came the response that I had hoped to hear. A 3D CT Scanner capable of imaging the standing patient had been developed. Its’ manufacturer had previously developed a game-changing 3D CT for use by dentists and oral surgeons. Their dental CT was called the iCAT and it quickly became the new standard worldwide due to its groundbreaking ability to produce high resolution 3D CTs using very low radiation.
It has contributed significantly to improvements in the quality of clinical services offered by dental professionals. Then their genius engineers turned their attention to orthopedics, developing the PedCAT which is considered such an important advancement in diagnostic imaging that it is likewise quickly becoming the new global standard for human foot and ankle specialists. While this CT was finishing its FDA approval process I approached the company and asked them to work with me to create a design for a CT capable of scanning the standing horse.
Two years later we are ready to bring this CT to the equine veterinary world to better serve our equine patients. I was the recipient of the audience award for the best innovation to improve the sport of horseracing at the Global Symposium on Horseracing and Gaming held in Tuscon Arizona in December 2015 for my work to bring The Standing Equine 3D CT Scanner to equine veterinarians to improve horseracing safety.
What makes this CT unique, and why do I say that it will yield information so helpful that we will be able to prevent the development of chronic pathologies that plague too many sport horses often at the time they are reaching their peak ability?
Traditional CT and X-Ray- The Current Standard
Traditional CT imaging requires the horse to be under general anesthesia while its’ unloaded limb is scanned. This presents severe limitations in accessibility due to the requirement that the horse undergo general anesthesia and must travel to a specialized veterinary clinic where such services are available. This adds not only to the cost but more importantly to the risks associated with the procedure. Another consideration is the high level of radiation needed to produce traditional CT scans.
Until now, the risk/benefit associated with CT scanning has prevented the routine use of this technology to screen horses for the earliest signs of pathologies at a time when they are able to be treated or managed to achieve full recovery. In addition, imaging studies of an unloaded limb fail to provide key information about the positions of the bones while under load so that areas of stress can be identified and the cause can be eliminated.
Traditional 2D x-ray is not sensitive enough to identify many of the earliest critical signs of bone and joint injury. It also limits the anatomy examined to a few fixed projections whereas each 3D CT scan collects radiographic data in the full 360 degree field, in 0.3mm slices, making it easy to identify and precisely locate even the smallest of lesions.
The Development of Bone and Joint Pathologies
Initial injury to bone in sport horses is typically undetectable by x-ray and often presents with minimal or no clinical signs. Increased skeletal work load can occur deliberately through carefully measured increases in training programs or inadvertently through a sudden change in training surface, intensity of training, or farrier practices.
This causes stress and micro damage to bone and joints and this injury, if it is allowed to heal properly, is the natural process through which tissues strengthen. If it isn’t allowed to heal properly, the stage is set for permanent damage that will have to be managed, often with medication for the rest of the horse’s diminished career.
The challenge for horsemen and veterinarians is to figure out how much stress is enough for proper strengthening and how much is too much. How much time off does your horse need after a heavy training session or competition? Without a means to examine bone in such detail that edema and micro damage can be definitively detected we are all just guessing.
Skilled horsemanship and patience in training go a long way to minimize the damage and allow healing and strengthening to occur but all too often, through the prevalent use of joint injections of hyaluronic acid, regenerative substances or corticosteroids, we often mask the signs of micro damage and keep the athletic horse in full training which results in irreversible damage to bone and joints. The x-ray will look clean when in fact damage can be significant from the standpoint that full recovery may no longer be possible. The stage is then set for chronic arthritis with diminished athletic performance or a shortened career.
How can we avoid this? By screening horses for signs of injury when they can heal with minimal rest, training intensity adjustment, biomechanical modification or medical therapy and being sure the injury has healed before resuming intensive work.
The Equine Standing 3D Scanner
The benefits of this Equine Standing 3D CT Scanner to the veterinary professional, owner, trainer and farrier are numerous but listed here are a few of the advantages it offers:
Easy on the Horse
➢ Scans the horse while standing on level ground;
➢ Scans both limbs simultaneously- either both front or both hind;
➢ Scans from above the carpus or tarsus through hoof;
➢ Scans are completed in roughly one minute;
➢ Uses very low radiation- comparable to that of a single human chest x-ray;
➢ Scanner is walk-through in design and very horse-friendly;
➢ Scanning is extremely quiet with no moving parts visible to the horse;
➢ Scans can be done using short acting sedation;
➢ Scans produce the highest resolution imaging studies (capturing 0.3mm slices) capable of revealing subtle pathologies (when full recovery is still possible) that are not visible on x-ray;
➢ 3D imaging studies allow veterinarians and farriers to see the anatomy under normal load to identify stressed areas and to evaluate 3D biomechanical status;
➢ Scans enable the diagnosis of subchondral pathologies that often lead to chronic arthritis in sport horses and catastrophic breakdown in racehorses;
➢ Ease of use and radiation safety enable this CT to be used serially to track the recovery or progression of injury so that we can better understand what veterinary treatments and management and training practices are beneficial to full recovery;
Access for All Horses
➢ CT can be installed into a trailer to enable it to reach horses wherever they train and compete;
➢ CT plugs into a standard electrical outlet;
➢ Cost effective with an anticipated cost to owners comparable to that of a typical series of plain x-rays;
Specialists and Research
➢ Imaging studies are captured and stored digitally enabling access to review by experts worldwide;
➢ Enables the isolation and examination of any individual bone, including otherwise hidden joint surfaces (see video);
➢ Enables evaluation of bone density through the use of colors;
➢ Enables the measurement of bone cortical thickness through examination of any bone in cross sections;
➢ Allows surgeons to precisely evaluate fractures or other boney lesions in 3D so that surgical approach and methods can be worked out before the horse is on the table and the owner can be provided a reliable prognosis.
The use of this CT in equine podiatry will allow us to identify and measure the effect of trimming and shoeing practices on biomechanics and the stress on bone, in 3 dimensions. Fully isolating the navicular bone and being able to examine it on all sides, including those previously hidden on standard radiographic images will be of enormous help to veterinary clinicians and researchers.
2) Subchondral Pathology
Subchondral pathology is damage to the area of bone that lies immediately beneath the joint cartilage. Research has shown that this injury precedes irreversible arthritis and in racehorses, it is associated with catastrophic breakdown. Subchondral pathology includes edema, micro fracture, and sclerosis. The ability to screen horses for this type of injury, which is a natural response to increased workload on bone, will enable the prevention of permanent damage to joints and bone. Used as a screening tool, it will prevent fatalities in horse racing improving safety for horse and rider.
3) Surgical Evaluation
Surgeons will be able to understand the precise nature and location of a fracture in 3D which improves their ability to offer a prognosis and greatly assists them to determine the best surgical approach. Since this CT can be done in the standing horse and through a splint or cast, the horse can be stabilized and surgeons at any location worldwide can review scans through file sharing before the horse is shipped to a clinic.
4) Tracking Pathologies to Assure Full Recovery
One of the challenges to understanding the development, rehabilitation, and success or failure of treatment of joint disease and bone injury is that traditional x-ray is not sensitive enough to identify, grade and track the healing process. This CT will allow veterinarians to diagnose and then track recovery of injury to bone through repeated scans so that we can assist clients to prevent their sport horses from developing permanent career ending arthritis and other chronic bone pathologies.
Rehabilitation can now be objectively evaluated through repeated CT scans to monitor the success or failure of medical treatments and management and training practices that impact recovery.
6) Evaluation of Training Practices & Assessment of Bone Strengthening and Development
When we are trying to manage injuries that are undetectable on x-ray we must make educated guesses regarding when horses are ready to increase their training and return to competition. The use of serial CT scans to monitor the response of bone to training programs will help guide horsemen to develop the most helpful training regimes. The thickness of the boney cortex and the density of bone is influenced by training practices and surfaces and this CT is capable of measuring these effects so that trainers can adapt their programs to ensure optimal skeletal development in horses.
7) Biomechanical Assessment
Skeletal imbalance and the stress it creates on bone can be an underlying factor in injury to bone and soft tissue. Whole body skeletal balance is in large part determined by the biomechanical status of the hoof. This CT, being so easy and safe to use, will be able to be applied before and after farrier services when needed to ensure that the biomechanical balance of the horse is normalized.
8) Data Collection and Research to Understand the Development of Chronic Pathology
The study I have designed involves the collection of CT data on all horses in training at three racetracks as well as the collection of CT data on sport horses of all types, whether they are sound or unsound. This will serve to inform veterinarians and horsemen about the incidence and significance of both subclinical and clinical pathologies common to athletic horses and offer evidence of what influences their recovery or progression toward permanent lameness.
The Sport Horse Study
In order to make the best use of this new CT technology we must collect data on a large number of horses, both sound and unsound, so that we can discover the prevalence and significance of previously undetectable boney injuries.
I have designed a (minimum) one year study to be conducted through my nonprofit 501(c)(3) organization, Homecoming Farm, Inc., which has conducted research in equine sports medicine and rehabilitation and has provided education to veterinarians, veterinary students, farriers and horsemen since 1992. We will collect CT scan data on hundreds of sport horses in training over the course of at least one year. This scan data will be correlated with veterinary and training records.
Horses will be scanned at no cost or with minimal charge to their owners in exchange for their cooperation with the study. Some horses will be scanned repeatedly so that we can track the recovery or progression of pathologies correlated with the horse’s known medical treatments, farrier services and training protocols. Scan results will be provided to the horse owner and veterinarian and confidentiality will be ensured with our use of the data for analysis and publication.
During the data collection period we will offer ACVSMR internships to veterinarians and veterinary students so that as this technology becomes available at private veterinary practices worldwide, we can share our developing understanding of how to best use this technology to benefit horses. We will provide education in CT scan reading; imaging technique and acquisition; and we will share our database of 3D CT imaging studies so that veterinary colleagues can become familiar with the new diagnostic findings that will soon be available to them and help to provide a perspective on the significance to their equine patients.
Once the data collection phase is well underway, the manufacturer will make the CT Scanner available for purchase worldwide. I hope that you will help me to bring this important technology to all sport horses. If you would like to discuss this veterinary research and educational project or if you would like to assist with the funding of this important project, please contact me through the email listed below.
We also hope to expand this data collection to a wide geographic area by putting up to three CTs in use so that it can be introduced to a wider community of veterinarians and horsemen while collecting a statistically significant amount of data to help our equine veterinary community to better understand the incidence and significance of orthopedic injuries in sport horses and the factors that impact success or failure of rehabilitation.