Advances in the Canine Cranial Cruciate Ligament, 2nd edition

Regenerative Medicine and Cranial Cruciate Ligament Repair 375

(A) (B)

(C) (D)

Figure 45.5 The distal femoral
cartilage 1 year after (A) an
untreated cranial cruciate ligament
(CrCL) rupture, (B) conventional
CrCL reconstruction, (C)
bridge-enhanced CrCL repair, and
(D) bridge enhanced CrCL
reconstruction. Note the damage to
the medial femoral condyle in the
untreated knee, CrCL-reconstructed
knee, and the bridge-enhanced
CrCL-reconstructed knee (black
arrows) and the lack of damage to
the medial femoral condyle in the
bridge-enhanced CrCL-repaired
knee (white arrow). Source: Murray
& Fleming 2013. Reproduced with
permission from SAGE Publications.

and resorption of the CrCL stump (Magarian
et al. 2011).
Other key factors may be patient age and sex.
Younger animals have a stronger response to
PRP than older ones (Mastrangeloet al. 2010a;
Mastrangeloet al. 2010b; Magarianet al. 2011).
The reason for this is an ongoing reduction of
growth factor receptor expression on ligament
cells with increasing age (Vavkenet al. 2010).
More recently, female pigs have been shown
to have a poorer response to CrCL reconstruc-
tion than male pigs (Kiapouret al. 2015a) (Fig-
ure 45.6). Interestingly, if the postoperative time

allowed for ligament healing is extended, for

example by using stronger suture material in

the CrCLrepair, the cross-gender differences are

equilibrated (Kiapouret al. 2015b).

Preclinical studies for CrCL repair

A body of work has been created describing

the progress towards developing a successful

method for primary CrCL repair, supported by

a collagenous biomaterial and autologous blood

cells (Murrayet al. 2006; Murrayet al. 2007a;

(A) (B)

AP30

Side-to-Side Difference (mm)

% Contralateral Intact

p = 0.028

p = 0.072 p = 0.032

p = 0.023

Male Male

80

60

40

20

0

10

8

6

4

2

0

Female Female

p = 0.058

p = 0.043

AP60 AP90 Yield

Load

Maximum

Load

Linear

Stiffness

Figure 45.6 Sex-related differences after CrCL reconstruction in the porcine model. Note the inferior mechanical
properties and increased abnormal laxity in the female group. Source: Kiapouret al. 2015a. Reproduced with permission
from SAGE Publications.