Explanation of No. 2.
- 1. The extensor metacarpi tendon.
- 2. The extensor metacarpi obliquus tendon.
- 3. The flexor metacarpi internus tendon.
- 4. The back sinews.
The letter a denotes the only spot where the
knee-joint could probably be opened by a fall
without lacerating a synovial sheath or
injuring a tendon.
Anatomy is, under the circumstances, a fair guide. Where numerous structures are involved, a well-grounded learning is requisite for accurate judgment; but as regards the knee of the horse, the spot whence the synovial discharge issues is of all importance. The incision must either be very deep and gaping, (all subjacent structures being divided before the knee-joint can be exposed,) or else the wound must affect a very circumscribed place. The reader, by consulting the above anatomical engravings of the horse's knee, will remark how closely it is laced about with tendon. Each of the tendons, when crossing the joint, is embraced in a synovial sheath. From such information, it will instantly be seen how far more likely a sheath is to be lacerated than the joint is to be punctured.
The single point where the joint could be entered without severing tendon, lies rather on one side than directly in the center. The vulnerable spot is therefore not exposed to the full force of the blow. To lay bare the joint by an ordinary fall several parts must be divided. Rarely is an accident witnessed of so fearful an extent. Generally that which is spoken of as open joint proves to be no more than punctured sheath, the presence of synovia being commonly accepted as the proof. But when the joint is really laid open, the immense flow of synovia—so many sheaths being severed—should at once prove the fact.
PROBING BROKEN KNEE.
The probe must next be used. In the first instance it should be employed to ascertain whether the fall has left any purse or sac at the inferior part of the joint. All which was enforced respecting the use of metallic wire to a raw wound must here be observed. The probe had better be altogether discarded than employed with the smallest approach to rudeness.
