Page 71 - Manual of Equine Field Surgery

CHAPTER 10

Annular Ligament Desmotomy

Joanne Kramer

INDICATIONS PROCEDURE

Annular ligament constriction caused by primary Open Technique

annular ligament desmitis (Figure 10-1) and A 6- to S-cm skin incision is made over the lateral

annular ligament constriction secondary to ten- aspect of the superficial digital flexor tendon

donitis or septic tenosynovitis. (SDFT) at the level of the palmar annular liga-

ment. The incision is made palmar to the neu-

rovascular bundle and should be just axial to the

EQUIPMENT palmar edge of the sesamoid bone' ( see Figure 10-

2). A small incision is made in the proximal

Closed techniques are performed with a Mayo border of the digital sheath or annular ligament,

scissors, bistoury knife, or groove director. a11d a groove director or forceps is passed under

the annular ligament to act as a guide for further

transection. The incision is continued through the

ANATOMY entire proximal annular ligament, being careful

not to damage the underlying tendons (Pigure

The palmar-plantar annular ligament attaches on 10-3). The flexor tendons and exposed sheath

the abaxial surfaces of the proximal sesamoid are examined for adhesions. If present, they are

bones and partially surrounds the tendon sheath resected. The tendon sheath is lavaged as required

blending with its palmar-plantar wall and making by the primary problem.

up the palmar-plantar wall of the fetlock canal Subcutaneous tissues are closed with No. 2-0

(Figure 10-2). The proximal and distal extent of absorbable suture in a continuous or interrupted

the palmar-plantar annular ligament can be esti- pattern. The skin is closed with a11 interrupted

mated by palpating the apex and base of the pattern.

sesamoid bones.

Closed Technique

POSITIONING AND PREPARATION This is the preferred method if the tendons within

the fetlock canal do not 11eed to be exposed. A 2-

The horse is positioned in lateral recumbency. cm incision is made through the skin just proxi-

The circumference of the limb should be mal to the palmar annular ligament. The sheath is

clipped and prepared aseptically from the mid entered through a similar or smaller incision, and

metacarpus-metatarsus region distally. the distal extent of the annular ligament is defined

67