Page 685 - Adams and Stashak's Lameness in Horses, 7th Edition

Lameness of the Proximal Limb 651

Treatment the suprascapular nerve or scapulohumeral joint inflam-
mation that caused disuse muscle atrophy, or both. Anti‐
Both conservative and surgical treatments have been
VetBooks.ir described for management of horses with suprascapular ultrasound has also been suggested as a treatment. 15
inflammatory therapy is recommended. Therapeutic
nerve injury.
Initial treatment in all cases is
5,15,35,68,87,102
directed toward reducing inflammation in the region of
the suprascapular nerve. Stall rest with the administra- Surgical Treatment
tion of NSAIDs and the topical application of cold Surgical decompression of the nerve can be consid-
hydrotherapy or ice packs and topical anti‐inflammato- ered in patients that continue to exhibit signs of supras-
ries may produce a resolution of the clinical signs.
capular nerve dysfunction for 10–12 weeks. This time
frame is based on the rate of peripheral nerve regenera-
Conservative Treatment tion (1 mm/day) and the distance from the site of nerve
injury on the cranial border of the scapula to the
When conservative treatment is selected, stall rest is infraspinatus muscle (7–8 cm). Using these parameters
continued until shoulder joint stability returns, followed nerve function should return in 10–12 weeks. In horses
87
by confinement to a pasture for an additional 2–4 that show no improvement after 12 weeks or more of
months. In one study the mean time for resolution of the rest, entrapment of the suprascapular nerve by scar
gait abnormality was 7.4 months, and 7 of 8 horses tissue between the overlying ligament and the cranial
evaluated had a complete resolution of the joint instabil- border of the scapula is likely. Although the time frame
ity. The conclusions from this study were that stall rest for reversing neurogenic muscle atrophy in large ani-
35
appeared to be a viable alternative to surgery for the mals is not known, in humans, neurogenic muscle
treatment of suprascapular nerve injury. It can be specu- atrophy becomes dramatic after 4 months with loss
lated that surgical decompression may result in a faster of up to 80% of muscle fiber volume. It is generally
return to athletic function. accepted that functional reinnervation is unlikely after
Injection of a corticosteroid into the shoulder joint 12 months. 56,102 After that, irreversible changes within
may also be beneficial. In one report, 6 horses with sus- the muscle occur, and it is replaced by fibrous tissue.
pected suprascapular nerve injury were treated success- Surgical decompression involves removing a small
fully with intra‐articular corticosteriods. However, it is piece of bone from the cranial border of the scapula
68
uncertain whether these horses had a true neuropraxia of underlying the nerve (Figure 5.59). By removing the
87

C

A B
Figure 5.59. (A) Location of the skin incision (dotted line), crescent‐shaped piece of bone is removed from the cranial border
centered over the suprascapular nerve and cranial to scapular of the scapula (dotted line). (C) The bone has been removed and
spine. (B) The suprascapular nerve is identified, and a small tendinous band resected.