Guide to the application and use of the Dynamic Support System
• 1 Dorsal metacarpal plate
• 2 Dorsal pastern plate
• 3 Tension band
• 4 Locking screw for settings
• 5 Locking stud for attachment straps
• 6 Settings adjustment
• 7 Hinge
• 8 Inner lining
• 9 Metacarpal pad
• 10 Pastern pad
Application of the tendon support boot
As the support device is designed to fit snuggly onto the limb, the limb should be unclipped and unbandaged. If a wound is present, it should be covered with a nonadherent dressing and a thin layer of wound cover.
The device should be disassembled into its component parts – the main boot, the dorsal metacarpal plate (1) and the dorsal pastern plate (2). The desired setting should be selected by unscrewing the locking screw (4) on the back of the device (figure 1) and sliding the adjuster (6) so that it matches the setting number.
Setting 1 – Only provides support at full fetlock extension. Used during the later stages of rehabilitation when the horse is trotting/working
Setting 2 – Provides support at the walk and trot.
Setting 3 – Provides some support to the fetlock joint at all times.
Setting 4 – Provides a significant level of support when the horse is standing. Used when there is significant hyperextension of the fetlock joint or as an emergency splint thus the setting should be gradually reduced during the rehabilitation period to increase the proportion of load taken by the palmar/plantar soft tissues.
Note that the setting can NOT be changed while the leg is weight-bearing.
- The main device should be applied to the palmar aspect of the limb with the limb weight-bearing (figure 2) or lifted so that the device hinge is opposite the fetlock (figure 2).
- The dorsal metacarpal plate is then clipped onto the device using the eyed metal attachments (figure 3), ensuring that the plate is orientated correctly (‘top’ should be proximal on the limb).
- Finally, the dorsal pastern plate is fixed to the device in the same way as for the dorsal metacarpal plate, once again ensuring that the plate is orientated correctly (figure 4).
- After application, it is recommended that a thin cohesive bandage, such as VetWrap is applied over the entire outside surface of the device. While not essential this outer wrapping process is worth doing as it ensures that the horse does not damage or interfere with the device, particularly during the initial period when it is becoming accustomed to it.
External wrapping also has the added benefits of keeping any dirt away from the injury and the moving parts of the device as well as improving the overall security of the fasteners and adjustment mechanisms while in use.
Size Fitting & Adaptation for Smaller Animals such as Foals and Yearlings
While the device is made for full-size adult horses it can also be adapted very effectively for smaller animals such as foals or yearlings. In such applications, the device’s own soft Inner Lining material (8) can be removed and replaced with a custom made cotton & cohesive bandage of a suitable thickness as required to fill the extra space.
When doing this it is important that the bandage be applied as evenly and smoothly as possible to avoid varying thickness and any uneven pressure under the device. The bandage should extend from the knee or hock level all the way down to the coronet band of the hoof. When the correct thickness of cotton & cohesive bandage is achieved the device should then fit snuggly over the bandage without requiring excessive pressure to apply.
In some cases, both the supplied soft Inner Lining material (8) and additional bandaging can be used.
Note: In this method of adapting to smaller animals, it is important to remember that it is only necessary to replace/add the Inner Lining Material (8) with the cotton bandage. The front foam pads elements (9) and (10) must always be used.
Removal
The process is essentially reversed.
- The limb is lifted and the dorsal pastern plate pushed against the pastern to unclip it from both sides of the boot (figure 5). It is then removed.
- The dorsal metacarpal plate is unclipped in the same way (figure 5).
- The device is then eased off the back of the limb.
When applying
- Metacarpal Plate (1) on first, Pastern Plate (2) on last.
When removing
- Pastern Plate (2) off first, Metacarpal Plate (1) off last.
Period of use
The Tendon Support Boot is intended to be worn during exercise only and it enables horses recovering from tendon or ligament injury to be exercised safely during rehabilitation giving the maximum chance of full recovery. It also means that horses can get back into light work quicker and the amount of pain suffered by the horse is noticeably reduced.
In some cases, the device can be worn when in the paddock and other long periods in the day (only under veterinary supervision).
The device is not intended as a replacement for a conventional stable cast or splint.
- Early stages of injury rehabilitation when there is significant hyperextension of the fetlock joint
- The device has four variable settings that take only seconds to adjust.
- The amount of support that the system provides to MCP joint extension and suspensory ligaments depends on which of the four settings is selected. The highest setting (setting 4) provides total support to the limb and is used for immediate post-injury treatment when maximum support is required.
- The device at setting 4 can also be used as emergency aid to stabilise an acute injury and is an excellent means of instantly enabling a severely injured horse to walk into an ambulance and transport it from the racetrack/show grounds to the hospital. Used this way the device will also reduce the risk of further injury occurring during the immediate post-injury period and in transportation.
Later stages of injury rehabilitation when the horse is exercising
As the rehabilitation progresses, the device should then be used intermittently for exercise sessions ranging from 10 to 35 minutes per day. As the horse improves over time, the setting is gradually reduced through settings 3 and 2, down to the lowest setting 1 which is for the later stages of rehabilitation when the horse can once again resume training.
Once fetlock support has returned, the device can be used when there is an increase in the exercise level – for example, the introduction of trotting or initial turn-out.
At the same time, there would be a gradual reduction in the settings so that there is a gradual increase in the amount of load applied to the soft tissues while still providing support and higher loading.
Once the horse is considered to have made a significant recovery, use of the device can then cease.
The importance of not over-supporting for too long
While it may seem sensible to give constant support to an injury, over–supporting for too long or depriving a horse of exercise altogether, can in itself have adverse effects such as poor quality healing and laxity in the limb. Therefore it is important to reduce the support setting as healing progresses.
Without challenging the injured tendon or ligament in this way, the tendon or ligament’s capacity to heal and regain its own independent strength and resilience is reduced.
The Tendon Support Boot, at the correct setting, allows the soft tissue injury to be challenged safely. It is important to check regularly for the development of any sores.
These are unlikely if the device is correctly fitted and applied but the most common sites are medially and laterally at the level of the fetlock joint.
If any bandage material is applied to the limb this should be replaced on a daily basis at the same time.
The four settings that can be selected relating to the amount of fetlock support required.
Placing the boot on the back of the limb with the device hinge opposite the joint.
Attaching the dorsal metacarpal plate.
Applying for the dorsal pastern plate with the limb raised and correctly applied device.
Removing the dorsal pastern plate first with the limb raised.
Sizing Guide - DSS
The tendon support device is available in three sizes – Small, Medium and Large.
To determine the correct size it is necessary to measure the width of the fetlock joint at the widest point when viewed from the front. (See Example below)
- Small-Size is suitable for animals with a fetlock joint width measurement ranging from 70mm to 85mm approx.
- Medium-Size is suitable for animals with a fetlock joint width measurement
ranging from 85mm to 100mm approx. - Large-Size is suitable for animals with a fetlock joint width measurement ranging from 100mm to 110mm approx.
In this example, the width of the fetlock joint is 70mm (7cm)
Contra-indications
- Wounds present directly under the pressure points of the device which are dorsal pastern and metacarpal/metatarsal regions, palmar/plantar fetlock and medial and lateral fetlock.
Prepared by Professor Roger K.W. Smith, Professor of Equine Orthopaedics, The Royal Veterinary College and edited by Henk Offereins DVM, MRCVS, MVSc Veterinary Director, Equine Tendon International.