y Bassi, and
good results in appropriate cases have been reported by Cadiot, Merillat
and Schumacher. This operation has been found a corrective in cases of
outward luxation as well as those of upward dislocation of the patella
when resorted to before the trochleae are worn from frequent luxation.

_Outward luxation of the patella_ is occasioned by a lax condition of
the internal femeropatellar ligament or a rupture of the same so that
the patella slips over the outer femoral trochlear rim and permits of an
abnormal flexion of the stifle joint. The outer trochlear rim being the
smaller of the two, inward luxation does not occur in the horse. With
the patella disarticulated in this manner, the action of the quapriceps
femoral group of muscles has no effect on the stifle joint and,
therefore, flexion of this articulation occurs as soon as the subject
attempts to sustain weight and the leg collapses unless weight is at
once taken up by the other member if sound.

As a rule, the reduction of this form of luxation is not difficult. The
patella may be pushed inward and into position without manipulation of
the leg. Retention of the patella in position is a difficult problem.
Bandaging is considered impractical and is not ordinarily done in this
country. Benard, according to Cadiot and Almy, recommends bandaging with
a heavy piece of cloth in which an opening is made through which the
patella is allowed to protrude, and by turning such a bandage snugly
about the stifle several times, the patella is held in position. This
bandage should be kept in place for about ten days.

In young and rachitic animals outdoor exercise and a good nutritive
ration for the subject are indicated. Hypophosphites in assimilable form
may be beneficial, and vesication of the patellar region contributes to
recovery.

Where extreme luxation is present in both stifles, the prognosis is
unfavorable. In such cases, degenerative changes may exist and in some
instances the ligaments are so diseased and elongated that regeneration
is impossible. Williams[46] reports a case where bilateral "floating"
(outward) luxation was present and extensive degeneration changes
affected the articulation.

In subjects suffering frequent dislocation of the patella (habitual
luxation) it is possible in some cases, to prevent its occurrence or at
least to minimize the distress occasioned by momentary luxation, by
keeping the animals in wide stalls so that "backing" is un