Page 313 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

288 CHAPTER 1

VetBooks.ir 1.8 Soft-tissue injuries

Soft-tissue structures, including tendons and The prognosis is guarded to poor and an early, accu-
ligaments but also their synovial sheaths and rate diagnosis is paramount to improve the chances
other connective tissue elements, are major for recovery.
components of the musculoskeletal system. Most of these soft-tissue injuries appear to have a
While bones are the main supporting struc- similar pathophysiology based on repeat, cyclic and
tures, muscles, ligaments and tendons are under overuse trauma or, less commonly, direct trauma to
significant stress in athletic animals. Soft-tissue the limb.
injuries are consequently extremely common.
The advent of ultrasonography and, more DIAGNOSTIC TECHNIQUES
recently, of MRI has enabled us to recognise
an increasing variety of conditions, while there Localisation of the site of pain, in some cases by
probably remains many more still to discover. regional or intrasynovial anaesthesia, is important as
Many soft-tissue injuries heal slowly and soft-tissue injuries are subtle and difficult to detect
poorly, often with significant loss of func- using observation and palpation alone. Furthermore,
tion. This is a source of major losses in the there is often significant regional oedema, making
equine industry. New approaches to therapy are precise location of a lesion difficult. The clinician
emerging, bringing hope of a better and faster must also be aware that obvious alterations are not
recovery, although they are very much in their necessarily clinically significant or at least not the
infancy. cause of the current lameness.

TYPES OF INJURY Ancillary diagnostic techniques
Radiography
Horses are particularly prone to tendon injuries Radiographic examination may be useful to rule
because of their weight, the extreme anatomical out concurrent or associated bony/articular abnor-
simplification of their distal limb and the speed at malities (e.g. fractures, splints) but also to look for
which they can work, all of which combine to induce abnormal bone reaction (e.g. sclerosis, new bone
enormous loading on tendon and ligament struc- formation, entheseopathy) at the tendon or ligament
tures. Injuries to the superficial digital flexor tendon insertion sites.
(SDFT) and the suspensory ligament (SL) are the Positive contrast bursography, tenosynoviogra-
most common and affect a large number of race and phy or arthrography may be useful in some cases,
sports horses. There is, however, a much wider range to ascertain communication between fluid-filled
of tendon and ligament conditions and it is increas- cavities (e.g. between joint cavities, tendon sheaths
ingly clear that most limb soft-tissue structures can and bursae) or to look for subtle fistulas. Injection of
be involved in either traumatic or degenerative injury. an iodinated, positive-contrast material into a given
The diagnostician must therefore acquire an increas- synovial cavity, through an area devoid of infected
ingly thorough knowledge of soft-tissue limb anat- material, may show leakage of the fluid through a
omy and the use of specific diagnostic techniques. wound or opacification of another synovial cav-
Disorders affecting articular and periarticular ity with which it does not normally communicate
ligaments, capsular structures and muscle injuries (Figs. 1.545, 1.546).
will be dealt with elsewhere.
Tenosynovitis (inflammation of tendon sheaths) Ultrasonography
is commonly recognised in all types of horse and Ultrasonography can be used to examine all soft-tis-
pony. The complexity of the underlying pathology sue structures, as long as they are not separated from
of these cases is becoming increasingly understood. the skin by bone or gas. This includes the insertions