Evaluation and Management
Each year, the ability of the MRI to visualize articular cartilage defects
improves but is far from perfect. The MRI is excellent for meniscus tears
but not for articular cartilage. A bone scan is sometimes necessary
to identify difficult to see lesions.
X-rays are helpful for advanced degenerative changes or osteochondral defects.
If the knee became swollen following the injury, an MRI will be valuable for
characterizing the likely injury.
If all the studies are normal and the patient continues to have knee pain
that is characteristic of cartilage problems, a "diagnostic arthroscopy" may be
done.
Treatment
Note the following discussion regarding treatment
and surgery is not intended for arthritic or degenerative knees. If
surgery is necessary for a arthritic degenerative lesions, the best choice is
usually a joint replacement type of surgery.
R.I.C.E (Rest, Ice, Compression and Elevation) is the best method for treating
minor injuries in the first few days. An ACE wrap may add support and
comfort to the limb. Early
evaluation by a orthopaedic surgeon is important if the knee is symptomatic for
more than one day. If the injury occurred while playing sports and the
swelling is severe, there is a high likelihood that a serious injury occurred.
If necessary, take over the counter NSAIDs (non-steroidal anti-inflammatory
drugs, such as ibuprofen or acetaminophen) to manage swelling and pain.
For degenerative arthritis low
impact exercises such as swimming, inclined stationary bike or elliptical
machine will help maintain the knee motion and strength. Activity
modification is important to curtail painful activities. A Physical Therapist
(PT) may be helpful in teaching the proper ways of
exercising and strengthening without overloading the joint and making the
problem worse. Viscosupplementation injections (Synvisc®,
Orthovisc®), steroid injections
(cortisone) and anti-inflammatories (Naprosyn®,
Celebrex®) serve as the foundation of the non-operative treatment.
Arthroscopic Knee Surgery: If the symptom
are not
satisfactory and there is persistent functional impairment, then arthroscopy may
serve as the next viable option. The risk and benefit profile needs to be
balanced. Most arthroscopies can be performed with local anesthesia and
small amounts of intra-venous drugs. The procedure is performed with the
patient fully alert and awake (and comfortable!) as same day outpatient surgery.
The
arthroscopic debridement procedure is used to wash out the cartilage
debris, trim or smooth-out jagged pieces of
cartilage, and attempt to heal or re-surface small denuded areas.
Microfracture chondroplasty is a arthroscopic procedure in which
the surgeon creates multiple
tiny puncture
holes in the denuded areas (exposed
bone) using a sharp surgical pick. The punctures in the bone allow blood from the
bone-marrow to
escape and pool within the cartilage defect. Eventually the pooled blood
will solidify into a type of cartilage which can cover the denuded defect. In approximately 80%
of cases there
is an acceptable degree of filling of the defect and symptom relief. The major downside to microfracture
chondroplasty is the necessity for crutches and strict use of a motion
machine (CPM) for 4-6 weeks. There is also a question of long-term
durability beyond 5 years after the surgery. Nonetheless the arthroscopic
debridement and the microfracture chondroplasty serve as the first-line surgical
procedures before embarking onto much more complex options.
For larger deeper
articular
cartilage defects or those defects which failed the above
surgery, the treatment may be much more complex.
A handful of
innovative procedures have been developed and studied in the last 15 years.
Treatment options are actually few and include:
Autologous Chondrocyte
Implantation (ACI, Genzyme, or Carticel)
Osteochondral Plug Transfer ("OATS" or Mosaicplasty) using your own plugs or
fresh cadaver plugs
Bulk Allograft Transfer (large "fresh" cadaver grafts, including hemi-condyles
and plateau)
Small plugs of cartilage may be
taken from a less critical part of the knee and inserted into the painful area,
osteochondral autograft transfer (OATS). These
plugs look like dowels which can be tapped into the prepared cartilage defect.
Once the defect is pacted with the plugs the knee is protected with crutches
until the plugs grow into the surrounding bone. The surface of the plugs
consist of cartilage which will form the new surface previously void of
cartilage. These plugs may be autograft (your own) or allograft (cadaver). Autologous Chondrocyte
Implantation (aka: ACI, Genzyme, Carticel) is a procedure in which the patient’s own cartilage cells
are harvested from a less important site within the knee, grown in a laboratory, and then re-implanted into the
cartilage lesion of the knee. The procedure requires two surgeries, one
for the harvest and the second for the implantation. Lastly bulk fresh allograft
transplant is used when the area of cartilage loss is
large or massive. The results have been good in selected cases of large
osteochondral defects (OCD) and small avascular necrosis (AVN). When performed properly each one of these
surgical options
may yield good results. Keep in mind that the recovery from these
procedure is about 1 year. The time on crutches and the amount of PT could
be up to 3 months. It is also important to note that excellent results are
not routinely achieved, therefore patient expectations have to be realistically
tempered.
Summary
Treatment of articular cartilage defects, whether traumatic or
degenerative, are highly challenging. The greatest challenge is
determining which treatment option is best suited for the individual case.
The surgical options may include highly complex procedures and therefore the
decision to have surgery should be carefully made.
Although the recovery and rehabilitation period is long, good results are
achievable in properly selected cases.
