Extracapsular Stabilization 193(A) (B)Figure 25.4 The Ruby Joint Stabilization System represented in a bone model (A) and a lateral projection stifle
radiograph of a clinical case (B). Source: Images courtesy of Dr. Otto Lanz.
anchors is purported to minimize wear on the
Dyneema®fibers.
Suture material
As discussed, the suture material can be either a
monofilament or a multifilament line. Monofil-
aments may have lower infection rates (Kor-
vicket al. 1994), while multifilaments tend to
be superior in strength and stiffness, and have
a greater resistance to elongation (Burgesset al.
2010; Roseet al. 2012). Nylon leader line is the
most commonly used monofilament suture; it
is mechanically superior to nylon fishing line
(Caporn & Roe 1996; Nwadike & Roe 1998) and
also to smaller-diameter polypropylene suture
(Lewiset al. 1997). Nylon leader line is avail-
able in 20–80 pound test strengths; the test
strength of the material should approximate the
weight of the animal (Piermatteiet al. 2006;
Kowaleskiet al. 2012), and one or two strands
can be placed. When two strands are desired,
many surgeons use two individual lengths tied
individually, but it has been suggested that a
single continuous length of suture overcomes
the inevitable uneven tension on individual
strands, which may lead to earlier failure (Wal-
laceet al. 2008). Some studies have shown a
weakening of the leader line after steam ster-
ilization (Lewiset al. 1997) or ethylene oxide
sterilization (Andersonet al. 1998), while oth-
ers have shown no difference in mechanical
properties after sterilization (Caporn & Roe
1996; Sicardet al. 2002). Generally, it is recom-
mended to minimize the number of sterilization
cycles where possible, particularly with steam
sterilization.
Many different multifilament products are
available for extracapsular suture stabilization,
which can be composed of polyethylene (e.g.,
Dyneema®), polyester, polybutester, Kevlar,
or a combination of materials. FiberWire® is
a cylindrical multifilament composed of a
core of multiple strands of high molecular
weight polyethylene surrounded by a braided
polyester jacket, while FiberTape®isa2mm-
wide tape with a similar material make-up
to FiberWire®. Early in the development of
LFTS, orthopaedic wire was used but radio-
graphs revealed wire breakage in 26 of 33
cases (79%) by 6 weeks postoperatively (Stork ̈
et al. 2001); consequently, use of wire is not
recommended.