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Cartilage lesions
Cartilage defects in the knee joint are frequently
present. In 1000 consecutive patients who
underwent an arthroscopy, 61% had a chondral
or osteochondral lesion, and 19% presented with
a focal (osteo)chondral defect [9]. The incidence
of cartilage defects in the patellofemoral joint is
around 35% with 69% on the patella, 22% on
the trochlea and 8% on the both.
Articular cartilage lesions of the knee are known
for their limited potential to heal spontaneously.
Persistent defects in the knee will frequently
become symptomatic andmany progress toward
secondary osteoarthritis (OA), affecting daily
living and quality of life [2, 4, 7]. On imaging,
these lesions are often associated with bone-
marrow edema (BME) on MRI. The under
standing of the relationship of structural changes
in an affected joint and the subsequent
development of OAcould lead to new treatment
strategies to prevent and treat this debilitating
condition [6]. Treatment modalities of joint
surface lesions aim to restore pain-free joint
function by promoting the formation of repair
tissue that has the structure and durability of
natural hyaline-like articular cartilage [5, 12].
Interventions intended to re-establish the
cartilage surface by tissue repair includemarrow
stimulation techniques such as microfracture
(MF) [15], mosaicplasty [8] or regenerative
approaches such as autologous chondrocyte
implantation (ACI) [2] and other variations on
chondrocyte-based therapies.WhileMF consists
of a single-step arthroscopic procedure, ACI
requires an arthroscopic intervention to obtain a
good-quality cartilage sample for expansion
and a subsequent mini-arthrotomy to implant
the expanded chondrocytes.
Osteoarthritis
Osteoarthritis is a chronic disorder characterized
by softening and disintegration of articular
cartilage, with reactive remodeling phenomena,
osteoblastic activity in subchondral bone, new
growth of cartilage and of bone (osteophytes) at
the joint margins, and capsular fibrosis. Venous
congestion and microvascular hyperpression in
subchondral bone has repeatedly been reported
[11]. Osteoarthritis is the most common joint
disease and one of the most frequent causes of
physical impairment [10].
Clinical forms of osteoarthritis
The disease can be subdivided into
primary
and
secondary
osteoarthritis. In
primary
or
idiopathic osteoarthritis the physiological and
biochemical characteristics of the tissues are
normal at the onset of the disease, but the joint
PatelloFemoral Cartilage
Defects – Is there always an
Osteoarthritic Terminus?
K.F. Almqvist, A.A.M. Dhollander,
P. Verdonk, J. Victor