148
46TH
ANNUAL
CONGRESS
OF
THE
SAEVA
SKUKUZA
16-‐20
FEBRUARY
2014
The results of treatment of linear tears of the deep digital flexor tendon have been
universally disappointing. Arensburg et al (2010) reported 98 horses with 101 linear
tears of the deep digital flexor tendon. Only 37 horses (38%) returned to the same
or higher level of exercise than that before surgery. Similarly, distension of the
tendon sheath was only resolved in 12 (12%) of horses and reduced in 56 (55%) of
limbs. Smith (2006) reported 30 / 55 horses with linear tears of the deep digital
flexor tendon became sound (55%), but only 20 / 50 returned to previous levels of
performance (40%). Smith and Wright (2007) also reported the results of 76 horses
with non-septic tenosynovitis of the digital flexor tendon sheath, and showed with
multivariate analysis that the presence of a linear tear of the deep digital flexor
tendon were associated with post operative lameness.
We have compiled the results of surgery for tear of the mancia flexoria. 52 horses
underwent surgery on 56 occasions and 63 tears of the manica flexoria were
identified. Four horses underwent a second surgery, 2 due to failure to respond to
the first surgery, and 2 due to the occurrence of lameness in another limb. Nine
horses had bilateral tears. All horses had digital tendon sheath effusion and in 100%
of cases where results of limb flexion were recorded (n=35), lameness was
exacerbated. The median duration of lameness was 3 months with a range of 2
weeks - 9 months. Intrathecal analgesia of the digital flexor tendon sheath abolished
or led to at least a 50% improvement in lameness in 22 horses, while a 4 point nerve
block abolished lameness in the remaining 10 cases. Cobs (25) and ponies (18) were
overrepresented in this study, compared to the surgical population of the hospital
(49% Thoroughbred) p=0.02 Fishers Exact Test. The median age was 13 years with
a range of 6-25 years. Hindlimbs were more frequently affected than forelimbs; 82%
(52/63) of tears of the manica flexoria occurred in the hindlimbs. Two horses have
less than 3 months follow up and in 4 follow up is incomplete. One horse suffered a
luxation of the tarsometatarsal joint in anaesthetic recovery and was euthanased, on
economic grounds, despite successful correction of the luxation. Five horses are
lame, and five have not returned to full exercise yet, either due to other conditions,
or intermittent low-grade lameness, and the remainder is sound and has returned to
pre-operative use, 36/46 (78%). Surgical findings revealed chronic thickened manica
flexoria adhered to the wall of the tendon sheath in nearly all cases. An annular
ligament desmotomy was performed 60 / 63 limbs (95%). Of the three without
desmotomy two are sound and one lost to follow up. Two horses underwent
debridement of the tears of the manica flexoria; of these one horse returned to
ridden exercise, the second horse remained lame and underwent a second surgery
to resect both hindlimb manica flexoria. This horse returned to ridden exercise,
following further medication of the tendon sheath.
We concluded that the prognosis for horses with tears of the manica flexoria
following tenoscopic resection of the manica was good. Cobs and ponies are more
likely to be afflicted with this condition. The sensitivity of ultrasonography for the
diagnosis of manica flexoria tears was low, but has improved with anticipation of the
condition. Due to one unsuccessful case we do not advocate debridement of torn
manica flexoria, though this case does not represent statistical significance (p=0.19).
References
1.
Arensburg L, Wilderjans H, Simon O, Dewulf J, Boussauw B. Nonseptic tenosynovitis of the
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