Page 75 - Manual of Equine Field Surgery

Annular Ligament Desmotomy
closed technique. The use of the open technique
increases the risk of complications, but with
appropriate postoperative care and monitoring,
complications are not common.
ALTERNATIVE PROCEDURES
Extrasynovial Transection
Performance of an annular ligament desmotomy
without entering the tendon sheath has· been
described.4The technique relies on the presence of
a small extrasynovial space between the SDFT and
the palmar annular ligament. A 2-cm skin incision
is centered between the proximal border of
the annular ligament and the ergot on palmar or
plantar midline. Sharp dissection is continued
through the subcutaneous tissues until the trans-
verse fibers of the annular ligament are identified.
Careful sharp dissection is continued through the
annular ligament until the division between the
annular ligament and longitudinal fibers of
the SDFT is identified through a 5-mm incision
in the annular ligament. Curved Kelly forceps are
directed through the incision in the annular liga-
ment to identify the dissection plane. The Kelly
forceps are opened several millimeters and a
No. 15 blade is used to incise the ligament. The
forceps are advanced distally and then turned and
advanced proximally to allow complete incision of
the ligament. In most cases, the palmar axial
attachment of the flexor sheath to the SDFT on
either side of midline can be seen i11 the surgical
field.
Desmoplasty
Desmoplasty of the annular ligament has been
described in four horses with primary annular lig-
ament desmitis.5 The procedure involves identify-
ing hypoechoic lesions i11 the annular ligament
71
and under ultrasound guidance, creating partial-
thickness incisions in the hypoechoic regions with
a No. 11 blade.
i
Endoscopc Transection
Endoscopy of the digital sheath with guided
transection of the annular ligament has also been
described'" and offers an improved prognosis for
horses with digital sheath pathology.
REFERENCES
1. Adams SB, Fessler JF: Palrnar-plantar annular liga-
ment division. In Adams SB, Fessler JF, editors: Atlas
of equine surgery, Philadelphia, 2000, WB Saunders.
2. Turner AS, Mcllwraith CW: Sectioning of the
palmar or plantar annular ligament of the fetlock.
In Turner AS, Mcilwraith CW, editors: Techniques
in large animal surgery. Philadelphia, 1989, Lea &
Febiger.
3. Gaughan EM, Nixon AJ, Krock LP, et al: Effects of
sodium hyaluronate on tendon healing and adhe-
sion formation in horses, Am J Vet Res 52:764, 1991.
4. Hawkins DL, Churchill EA: Extrasynovial
palmar/plantar annular ligament desrnotomy, Proc
Am Assoc Equine Prac 44:210, 1998.
5. McGhee JD, White NA, Goodrich LR: Primary
desmitis of the palmar and plantar annular liga-
ments in horses: 25 cases (1990-2003), J Am Vet Med
Assoc 226:83, 2005.
6. Fortier LA, Nixon AJ, Ducharme NG, et al: Teno-
scopic examination and proximal annular ligament
desmotomy for treatment of equine complex digital
sheath tenosynovitis, Vet Surg 28:429, 1999.
7. Nixon AJ, Same AE, Ducharme NG: Endoscopic
assisted annular ligament release in horses, Vet Sur._g
22:501, 1993.
8. Wilderjans H, Boussauw B, Madder K, et al:
Tenosynovitis of the digital flexor tendon sheath and
annular ligament constriction syndrome caused by
longitudinal tears in tl1e deep digital flexor tendon:
a clinical and surgical report of 17 cases in Warm-
blood horses, Equine Vet J 35:270, 2003.