Concurrent proximal suspensory desmopathy and injury of the proximal aspect of the accessory ligament of the deep digital flexor tendon in forelimbs and hindlimbs

Reasons for performing study:

There are no reports of proximal suspensory desmopathy (PSD) and concurrent injuries of the proximal aspect of the accessory ligament of the deep digital flexor tendon (ALDDFT).

Objectives:

To describe clinical features, response to local analgesia and ultrasonographic features.

Study design:

Retrospective study.

Methods:

Review of case records, January 2009–2014.

Results:

There were 8 horses with forelimb lameness, 4 unilateral and 4 bilateral (2 with bilateral injuries of the suspensory ligament [SL] and ALDDFT and 2 with PSD and injury of the ALDDFT in one limb and injury of the ALDDFT alone in the other). One horse had pain on palpation of the proximal aspect of the ALDDFT. Lameness was abolished by palmar metacarpal (subcarpal) nerve blocks in 10/12 limbs; in 2 limbs an ulnar nerve block was required to abolish lameness. There were 5 horses with bilateral hindlimb lameness; concurrent desmopathy of the ALDDFT and PSD was identified in one horse. In the other 4 horses there was a history of bilateral PSD which had undergone treatment. Recurrent lameness was associated with unilateral (n = 3) or bilateral (n = 1) PSD and desmopathy of the ALDDFT. In 2 horses there was soft tissue swelling in the proximomedial aspect of the metatarsus in the region of the ALDDFT. Lameness was abolished by local infiltration of mepivacaine in the proximoplantar aspect of the metatarsus in 3 limbs; in one limb a tibial nerve block was required to eliminate lameness. In all horses lesions were characterised ultrasonographically by enlargement of both the ALDDFT and the proximal aspect of the SL and a diffuse decrease in echogenicity. There was echogenic material between the SL and ALDDFT in 5 limbs.

Conclusions:

All soft tissue structures in the proximal aspect of the metacarpus/metatarsus should be evaluated ultrasonographically if pain is localised to this area.