The PATENT BAR SHOE
Also known as a rest shoe, the PATENT BAR SHOE is implemented in cases of acute severe flexor tendon injury. The shoe features a raised bar that extends between the heels and increases the angle of the foot. Several variations of the shoe exist; most farriers incorporate individual modification(s) according to personal preference.
By elevating the heels relative to the toe, tension along the flexor apparatus (which includes the deep and superficial digital flexor tendons and associated digital tendon sheath structures) is dramatically reduced. The healing process can then begin in an environment subjected to minimal tendon fiber distraction.
Of course, excessive elevation of the foot can have a variety of deleterious consequences. Such ramifications include:
- Excessive compression and compromise of the heel quarters
- Malarticulation of the coffin joint
- Excessive contraction of the flexor apparatus during the course of healing.
To avert the side effects that go along with prolonged heel elevation, the patent bar shoe allows for slow and gradual angle reduction over time. The bar is lowered approximately 0.75 inches (or 3 degrees) every 4 weeks until an appropriate hoof angle has been reestablished. Between each shoeing cycle, damaged tendon fibers have had a chance to heal and strengthen, thereby increasing their ability to tolerate a modest increase in applied stress as the heel of the foot is lowered.
This strategy enhances and accelerates flexor tendon healing while simultaneously reducing risk of reinjury.
As you might have guessed, patent bar shoes are only used on horses restricted to stall rest. The shoes do allow for limited (supervised) hand walking on a firm surface (such as a barn aisle), however. Of course, they are removed prior to the horse's resumption of any form of exercise beyond hand walking.