Mesenchymal stem cells (MSCs) have several properties that may support their use as an early treatment option for osteoarthritis (OA). This study investigated the role of multiple injections of allogeneic bone marrow-derived stem cells (BMSCs) to alleviate the progression of osteoarthritic changes in the various structures of the mature rabbit knee in an anterior cruciate ligament (ACL)-deficient OA model. Two months after bilateral section of the ACL of Japanese white rabbits aged nine months or more, either phosphate buffered saline (PBS) or 1 x 106 MSCs were injected into the knee joint in single or three consecutive doses. After two months, the articular cartilage and meniscus were assessed macroscopically, histologically, and immunohistochemically using collagen I and II.Aim
Materials and Methods
To investigate the risk factors for progression of articular
cartilage damage after anatomical anterior cruciate ligament (ACL)
reconstruction. A total of 174 patients who underwent second-look arthroscopic
evaluation after anatomical ACL reconstruction were enrolled in
this study. The graded condition of the articular cartilage at the
time of ACL reconstruction was compared with that at second-look
arthroscopy. Age, gender, body mass index (BMI), ACL reconstruction
technique, meniscal conditions, and other variables were assessed
by regression analysis as risk factors for progression of damage
to the articular cartilage.Aims
Patients and Methods
We report the clinical outcome and findings at
second-look arthroscopy of 216 patients (mean age 25 years (11 to 58))
who underwent anterior cruciate ligament (ACL) reconstruction or
augmentation. There were 73 single-bundle ACL augmentations (44
female, 29 male), 82 double-bundle ACL reconstructions (35 female,
47 male), and 61 single-bundle ACL reconstructions (34 female, 27
male). In 94 of the 216 patients, proprioceptive function of the knee
was evaluated before and 12 months after surgery using the threshold
to detect passive motion test. Second-look arthroscopy showed significantly better synovial
coverage of the graft in the augmentation group (good: 60 (82%),
fair: 10 (14%), poor: 3 (4%)) than in the other groups (p = 0.039).
The mean side-to-side difference measured with a KT-2000 arthrometer
was 0.4 mm (-3.3 to 2.9) in the augmentation group, 0.9 mm (-3.2
to 3.5) in the double-bundle group, and 1.3 mm (-2.7 to 3.9) in
the single-bundle group: the result differed significantly between
the augmentation and single-bundle groups (p = 0 .013). No significant
difference in the Lysholm score or pivot-shift test was seen between
the three groups (p = 0.09 and 0.65, respectively). In patients
with good synovial coverage, three of the four measurements used
revealed significant improvement in proprioceptive function (p = 0.177,
0.020, 0.034, and 0.026). We conclude that ACL augmentation is a reasonable treatment option
for patients with favourable ACL remnants. Cite this article:
We examined whether enamel matrix derivative
(EMD) could improve healing of the tendon–bone interface following
reconstruction of the anterior cruciate ligament (ACL) using a hamstring
tendon in a rat model. ACL reconstruction was performed in both
knees of 30 Sprague-Dawley rats using the flexor digitorum tendon.
The effect of commercially available EMD (EMDOGAIN), a preparation
of matrix proteins from developing porcine teeth, was evaluated.
In the left knee joint the space around the tendon–bone interface
was filled with 40 µl of EMD mixed with propylene glycol alginate
(PGA). In the right knee joint PGA alone was used. The ligament
reconstructions were evaluated histologically and biomechanically
at four, eight and 12 weeks (n = 5 at each time point). At eight weeks,
EMD had induced a significant increase in collagen fibres connecting
to bone at the tendon–bone interface (p = 0.047), whereas the control
group had few fibres and the tendon–bone interface was composed
of cellular and vascular fibrous tissues. At both eight and 12 weeks,
the mean load to failure in the treated specimens was higher than
in the controls (p = 0.009). EMD improved histological tendon–bone
healing at eight weeks and biomechanical healing at both eight and
12 weeks. EMD might therefore have a human application to enhance
tendon–bone repair in ACL reconstruction.
