Front Matter

378 Canine Sports Medicine and Rehabilitation

means that DFO can also be used to address
femoral torsion at the same time. Although
undoubtedly more invasive than a simple tibial
tubercle transposition, a DFO has a reportedly
low complication rate and good long‐term out­
comes (Brower et al., 2017).

Antirotational suture

A lateral fabellar‐tibial suture can be placed to
reduce internal tibial rotation. This is the same
technique used for the extracapsular repair
of CCL tears, and is commonly employed in
dogs that have concurrent MPL and CCL tears
(L’Eplattenier & Montavon, 2002b).

Soft tissue reconstruction

Surgical release of the tight tissues and imbrica­
tion of the loose tissues can be performed along
with selected procedures to help maintain the
patella within the trochlear groove (L’Eplattenier
& Montavon, 2002b).

Concurrent MPL and CCLR

Medial patellar luxation has been shown to
predispose animals to rupture of the CCL
(Campbell et al., 2010). When the two condi­
tions are diagnosed concurrently, surgical treat­
ment is designed to address both biomechanical
deficiencies (L’Eplattenier & Montavon, 2002b;
Langenbach & Marcellin‐Little, 2010; Yeadon
et al., 2011). In addition to antirotational suture
(extracapsular stabilization), modifications of
the TPLO and TTA procedures have been shown
to effectively treat concurrent MPL/CCLR
(Langenbach & Marcellin‐Little, 2010; Yeadon
et al., 2011).

Superficial digital flexor tendon
luxation

Anatomy

The superficial digital flexor is one component
of the common calcanean tendon. Originating
on the lateral supracondylar tuberosity of the
femur, it has two insertions onto the lateral and
medial surfaces of the calcaneus, before contin­
uing distally to the phalanges (Dyce et al., 1996).

The calcaneal bursa lies deep to the superficial

digital flexor tendon at the level of the tuber

calcaneus.

Pathophysiology

Luxation of the superficial digital flexor tendon

can be seen in either the medial or lateral direc­

tion; however lateral luxation is more common

due in part to the less well‐defined medial

retinaculum (Mauterer et al., 1993). Following

retinacular tearing, fibrosis of the torn retinac­

ulum and secondary bursitis may develop.

The high prevalence in Shetland Sheepdogs

and Collies suggests a hereditary basis (Gough

& Thomas, 2004). Pedigree analysis suggests

an autosomal recessive method of inheritance

(Solanti et al., 2002). Proposed risk factors

for  superficial digital flexor tendon luxation

include obesity (Bernard, 1977; McNicholas

et al., 2000), trauma (Bennett & Campbell, 1979),

and conformational abnormality (Solanti

et al., 2002).

Clinical presentation

Patients present with intermittent or continuous,

low‐grade, uni‐ or bilateral pelvic limb lame­

ness, usually before 1.5 years of age (Solanti

et al., 2002). Findings include swelling present

on either side of the calcaneus as well as a dis­

tinct popping of the superficial digital flexor

tendon as it luxates when the tarsus is flexed.

Discomfort is present on direct palpation of the

tuber calcaneus. Patients with accompanying

bursitis may have swelling over the tuber

calcaneus.

Diagnostics

Radiography, ultrasound, and MRI may be

used to confirm physical exam findings and to

rule out concomitant impairments.

Treatment

The torn retinaculum is imbricated with non­

absorbable suture and in some cases may