CHONDRAL DEFECTS

By a retrospective review of 31,516
knee arthroscopies there were:
41 % Outerbridge Grade III chondral injuries
19.2% Outerbridge Grade IV chondral injuries
(Curl W, et al. The Journal of Arthroscopies and Related
Surgery 13: 456-460, 1997)

Full-thickness chondral injuries,
secondary to work-related and sport
activities are common, with an
incidence of:
5-10% of acute hemartrosis
(Minas T. Instr. Course Lects. 48: 629-643, 1999)
CHONDRAL DEFECTS
CAUSES
mechanical
(trauma, instability)
degenerative/inflammatory
(OA/RA)
Mechanical insult such as high intensity
impact or torsional loading of a joint
premature wear-and-tear of the cartilage that
"cushions" the bone surfaces in a joint.
 the decline of the chondrocyte synthetic response and
the progressive loss of tissue ( osteoarthrosis, also referred
to as osteoarthritis, degenerative osteoarthritis, degenerative
joint disease)
 disruption or alteration of cartilage matrix
 the chondrocytes response to tissue damage
(anabolic and catabolic activity as well as
proliferation of chondrocytes)
ARTICULAR CARTILAGE LESIONS
Cartilage has limited selfrepair capabilities
articular cartilage defects
will ultimately result in
chronic tissue loss
OUTERBRIDGE classification
documents the progression of cartilagineous lesions:
Grade 0: normal articular cartilage
Grade I: softening and swelling of articular cartilage
Grade II: partial thickness
(fissuring on the surface)
Grade III: fissuring to the level of
subchondral bone
Grade IV: subchondral bone exposed
COMMON SYMPTOMS:

the joint cannot handle a load as heavy as
before

difficulty in flexing or straightening
completely the joint

Swelling/irritation/pain and "heating up“

the joint seems to get better for a while
before the symptoms simply reappear
later

Partial/full giving way
TREATMENT OPTIONS
Symptomatic/functional
(arthroscopic lavage with debridement)
drugs (chondroprotectors, NSAIDS, steroids)
rehabilitation
TKA - MKA
Effective repair (surgical techniques)
cell based repair/regeneration
CELL-BASED REPAIR: OPTIONS

bone marrow stimulation techniques
 perichondrial and periosteal grafts

osteochondral autografts (mosaicplasty/OATS)
 osteochondral allografts (massive reconstr.)

autologous cartilage implantation (A.C.I.)

tissue engineering (HYALOGRAFT® C)
BONE MARROW
STIMULATION TECHNIQUES
the sub-chondral bone is penetrated to reach a area of
vascularization, stimulating the formation of a fibrin clot
containing pluripotent stem cells able to reproduce – and
by fibrous metaplasia- to realize a riparative
fibrocartilageous tissue
BONE MARROW STIMULATION TECHNIQUES

drilling (Pridie,1959)
- to promote the ingrowth of blood vessels
and mesenchymal stem cells
- decompression of subchondral cancellous bone
intraosseous pressures immediate pain relief
(transient effect due to closure of drill holes by fibrous tissue)
BONE MARROW
STIMULATION TECHNIQUES

microfracture (Steadman, 1995)
- to break through the superficial
subchondral bone

abrasion arthroplasty (Johnson, 1984)
- abrasive removal of the superficial subchondral bone
DRAWBACKS

uncertain outcomes

unpredictable short term results
developing of fibrocartilage that lacks the
durability and many of the mechanical
properties of the hyaline cartilage

Deep holes/ fractures may weaken the
subchondral layer such an extent that the bone
is depressed leading to articular incongruity
(Insall, 1974)
OSTEOCHONDRAL AUTOGRAFTS OR
MOSAICPLASTY / OATS
(Hangody, 1991)
OSTEOCHONDRAL AUTOGRAFTS
(Hangody, 1991)
Osteochondral plugs are transferred from a non load bearing area of the
joint and implanted as a mosaic by a press-fit technique into the drill
holes in the recipient area of the defect by
arthroscopically or arthrotomically procedure
A composite cartilage surface consisting of 70% to 90% transplanted
hyaline cartilage and 10% to 30% of integrated fibrocartilage
Fibrocartilage fills the spaces between the transplanted grafts and
eliminates the incongruities of the surface
–
THE TRANSPLANTED HYALINE CARTILAGE IS
LINKED TO SUBCHONDRAL BONE
ADVANTAGES
STABLE CONNECTIONS BETWEEN CARTILAGE
AND BONE IS PRESERVED
–
CANCELLOUS BONE HEALS VERY RAPIDLY
6 ms
DRAWBACKS

complex surgical procedure
(meticolous attention to matching size and inlay fixation)


violation of subchondral bone
ambiguous indications  limited application of
one/few plug/s for chondral lesion lesser than 2-4 cm2
to avoid significative ratio of fibrocartilage tissue

donor site morbidity

not reproducible

Importance of the congruity of the graft surface to
avoid its degeneration (Lindholm)
THE BIOLOGICAL PARADOX
Cartilage tissue will not repair,
however
chondrocytes grow ex vivo
A.C.I.
(Peterson)

injection of cell
suspension

seal tight coverage with
periosteal flap
A.C.I.Autologous cartilage
transplantation
(source: http://www.genzyme.com/carticel)
> 4000 patients treated in the world
 good-excellent results at 3 yrs follow-up in 85%
of cases

A.C.I. INDICATIONS


Lesion size  2cm2
patient expectations with
regard to expected level of
activity
– high/low demand sports
– daily living activities

surgical invasiveness

compliance with rehabilitation
procedural costs

A.C.I. indications - lesion size  2 cm2 for a low
demand patient
Small focal defects ( 2 cm)
when treated with debridement or marrow stimulation techniques
 Have not been shown to progress to DJD (Homminga 1990;
Brittberg 1994; Hubbard 1996; Messner 1996)
Due to the fact that the chondral borders efficaciously
SHOULDER the exposed bone from damaging the opposing
articular surface
 Arthroscopic debridment offers symptomatic relief for up to 5
years in 50% of patients, with a 50% success returning to sports
and 75% success of being confortable with activities of daily
living
 is a minimally invasive procedure
 with low cost treatment
A.C.I. Indications
lesion size  2 cm2 for a high demand patient

Mosaicplasty, although converts a chondral
to an osteochondral injury
– minimally invasive
– low cost

A.C.I. when other techniques fail, has been
shown to be 90% successful in a revision
chondral surgery situation to return a patient
to a high level activity
A.C.I. indications - lesion size  2
cm2
In large ( 2-3 cm2) chondral defects, the repair tissue must prevent the
subchondral bone from bottoming out, so that secondary articular damage
does not occur to the opposing articular surface  DJD
A.C.I. is the first line treatment as this
A durable repair tissue with > 90% success
Large osteochondral allografts (?)
If A.C.I. fails
TKA, MKA
A.C.I. Indications




Tibio-femoral malalignment
Patello-femoral malalignment
ACL insufficiency
bone insufficiency (osteochondritis dissecans,
avascular necrosis, osteochondral fracture)
Must be managed PRIOR to, or CONCURRENTLY
managed with, the chondral injury
A.C.I.- limitations

problematic handling of coltures in
suspension

complicated surgical procedure

chondrocyte de-differentiation (cells
acquire a less specialized phenotype and loose the capacity to
produce essential molecules : chondrocytes assume a
fibroblastoid morphology and cease the production of
molecules typical of hyaline cartilage)
TISSUE ENGINEERING EMPLOYS
LABORATORY GROWN TISSUES
FOR THERAPEUTIC USES
Cartilage has limited self-repair capabilites
articular cartilage defects will ultimately result in
chronic tissue losses
To contrast this relentless outcome new
reconstructive techniques have been developed
such as
autologous cultured chondrocyte implantation
(ACCI)
medium-term results are encouraging
but with limitations

problematic handling of cultures in suspension

complicated surgical procedure

chondrocyte de-differentiation: cells acquire a
fibroblastoid phenotype and loose the capacity
to produce the typical ECM molecules able to
regenerate a physiological-like tissue
Hyaluronan-based
Tissue Engineering
Use of biomatherials derived from
jaluronic acid (Hyaff-11)
Ideal three-dimensional scaffold for the
cultivation of human autologous chondrocytes
1. Ability to restore the differentiated phenotype maintaining chondrocyte
capability to produce collagen type II (hyaline cartilage marker)
2. Improved and simplified implant technique
chondrocytes assume a
cease the production
fibroblastoid morphology
of collagen type II
typical of fibrocartilage
3 days
14 days
24 hrs
14 days
DAY 50
grafting on patient
DAY 0
DAY 28
cartilage
biopsy (150 mg)
cartilage
formation
in vitro culture
of
chondrocytes
DAY 14
Seeding on
HYAFF®
scaffold
FAB s.r.l APPROACH
Autologous
Chondrocytes
+
Tridimensional
hyaluronan
scaffold
BIO-ENGINEERED TISSUE
Hyalograft-C: technical advantages




easy to handle and
surgically apply
conformable
may be cut to fit
defect
no need for seal tight
periosteal coverage
Hyalograft-C:
indications and use
•


Symptomatic/ asymptomatic defects of
femoral condyle, knee cap and tibial plateau
caused by acute or recurred injures
Procedure
Arthroscopical taking of a cartilage biopsy
(150 mg)
Hyalograft-C:
indications and use



Pregrafting surgical curettage of the lesion
Application of graft in miniarthrotomy or
arthrotomy
Secured to the defect by applying a periostal
flap sutured at the edges of the lesion
Hyalograft-C:
indications and use
Post-surgical treatment:
 at surgeon’s discretion an articular drainage
and a compressive bandage should be
applied for 24 hours post grafting
 articular movement forbidden for 24 hours
postgrafting
 early postsurgical passive rehabilitation
therapy is advisable
Hyalograft-C:
indications and use





postsurgical passive rehabilitation :
Start with a passive rehabilitation with an excursion of 0°40°C and perform isometric exercises for quadriceps
Articular weight bearing gradually applied from the third
week
From 6-12 weeks increasing the weight bearing during
walking with crutches. Moderate walking, cyclette and
swimming depending on the state of the knee.
From the third month simulation of normal activity if no
pain is present.