Page 394 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.8 Soft-tissue injuries 369

VetBooks.ir 1.731 whenever a lesion is seen to extend to the syno-
Surgical treatment with tenoscopy is warranted

vial layer or if there is concurrent pathology in the
sheath that would require debridement (shearing of
fibres, synovial masses, adhesions, annular ligament
constriction) (see Fig. 1.718). Tenoscopy is recom-
mended both as a diagnostic and a therapeutic tech-
nique if there is any suspicion of tendon involvement
or in cases with tenosynovitis that fail to respond
to conservative management. PAL desmotomy has
often been advocated as a systematic approach but
does not seem to improve the outcome in most cases,
unless there is obvious constriction or restriction of
motion. This is best ascertained during tenoscopy,
although dynamic ultrasound examination may pro-
vide evidence of restriction.
The intrathecal injection of biological (IRAP ,
®
PRP) drugs is of questionable value. PRP probably
Fig. 1.731 A large adhesion is present on the palmar increases the risk of postoperative adhesion forma-
®
aspect of the DDFT in the pastern region (arrows). tion. Administration of IRAP may be of use but
There is mild distension of the digital sheath. The objective evidence is lacking of any beneficial effects
synovial membrane is thickened and irregular, at this stage. Intralesional biological therapies may
indicating chronic synovitis. be indicated and this may be performed under ultra-
sonographic or tenoscopic guidance. There is a
where fluid should be seen. This can, however, be major risk, however, of leakage of the substance into
difficult to ascertain, especially on low-field images, the sheath lumen and subsequent fibrosis/adhesion
as the fluid layer is very thin. formation.
Corrective shoeing is warranted in the long term,
Tenoscopy using adequate trimming to shorten the toe and
Tenoscopy is warranted in the presence of tenosy- encourage heel growth, and application of shoes
novitis unresponsive to medical/conservative man- with toe-rolling and increased heel support (egg-bar
agement without a clear identification of the cause, shoes or other devices with long/wide branches).
or when a marginal SDFT or DDFT lesion is iden-
tified on ultrasound. Many marginal DDFT tears Prognosis
are only identified on tenoscopic examination (see The prognosis is fair for central lesions, which often
Fig. 1.717). Tenoscopy of the digital sheath is a heal adequately after 6–9 months of rest and con-
difficult procedure as the sheath space is extremely trolled exercise. It is guarded to poor for deep tears
tight and iatrogenic injury to the tendons is easily that communicate with the sheath, due to poor
induced. healing of lesions and persistence or recurrence of
lameness, although early tenoscopic debridement
Management has been associated with a fair prognosis for return
Core lesions and lesions that do not extend to the to work (based on limited numbers of cases). Some
tendon margins are best treated conservatively horses will make an eventual recovery after a con-
with rest, cryotherapy and anti-inflammatory siderable length of time. Chronic tenosynovitis is,
therapy, followed by graduated, controlled exer- however, associated with a poor prognosis for return
cise. Tenosynovitis is dealt with as described in the to athletic activities. The prognosis is worse in the
Digital flexor tendon sheath section (see p. 357). forelimb than in the hindlimb.