Deciding Whether or Not to Undergo Surgery
Whether or not a torn anterior cruciate ligament should be reconstructed
depends upon many factors that are evaluated by both patient
and surgeon. Each patient must realistically assess the future
physical demand that will likely be placed upon their knee. High
demand physical activity that involves running, jumping, pivoting,
and "cutting" (see FIGURE 3)
presents the greatest risk for repeated knee joint subluxations
(and thus additional injuries such as bone bruises and cartilage
tears) in a knee without a functioning ACL
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FIGURE
3 - Activities that involve full-speed running, jumping,
cutting and pivoting are "high risk" for someone
with a torn or loose ACL. Treating such high-demand athletes
by rehabilitation and knee bracing alone has a fairly high
failure rate. |
In general, approximately one-third of individuals who tear their
ACL will do rather well without any form of surgery to repair
or rebuild it; another third will experience difficulties that
may involve limited re-injury and/or an unwanted decrease in activity
level, and the remaining third will do poorly if surgery is
not performed, re-injuring their knee time after time and often
causing irreparable cartilage loss. While many individuals
(usually those in the first 1/3 referenced above) possess excellent
natural compensatory mechanisms which reduce or eliminate recurrent
subluxation injuries, individuals at the opposite end of the spectrum
often cannot even perform their routine activities of daily living
safely without a functioning ACL in their knee! As of yet, no
method exists to accurately differentiate and identify with certainty
the "good compensators" vs. the "bad compensators",
in advance. Only "trial by fire" (i.e., a return to
physical activity without surgical reconstruction
of the ligament) allows this determination to be made. However,
the medical decision-making process with regard to the choice
of treatment is by no means totally blind.
Perhaps the most important predictive factor that assists
in this decision-making process is an assessment of the specific
physical demands that are likely to be placed upon the patient's
knee in the future. If high-performance athletic activity
that involves running, jumping, cutting and pivoting is realistically
on your future activity list, the odds of your knee suffering
recurrent injury (even with appropriate knee brace treatment)
are reasonably high and thus, surgical reconstruction of the ACL
should seriously be considered. On the other hand, if activities
such as cycling, rowing, straight-ahead jogging on level surfaces,
or aerobic fitness work on exercise machines (see
FIGURE 4) are going to be the most strenuous way in which
your knee will be used, conservative (non-operative) treatment
by way of a comprehensive program of rehabilitation and knee bracing
may work very well and thus save you considerable time, effort,
and expense.
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FIGURE
4 - There are many physical activities that pose
little or no risk to an individual with a torn or loose
ACL, such as using fitness exercise machines, cycling and
rowing. |
Another factor that enters into the decision-making
process is exactly how unstable your
injured knee joint is, both functionally (how frequently
and easily it "gives out" on you) and structurally
(how much measurable joint looseness it has). All knees do not
depend equally upon the anterior cruciate ligament for maintenance
of proper mechanical joint function. Some knees are more "cruciate
dependent" than others. For example, a person with a
relatively non-cruciate dependent knee might never even appreciate
or feel the difference between the knee's condition before
vs. after his or her anterior cruciate ligament was torn,
once the initial pain from the tear itself has subsided. On the
other hand, someone who possesses a very cruciate-dependent knee
may have difficulty performing even routine daily activities without
having their knee give out on them, after tearing their ACL. The
physical examination provided by an experienced knee surgeon can
rate or grade the degree of structural joint laxity or instability
that you have, thus providing another piece of data to be entered
into the overall decision-making equation. In general, a low-grade
instability combined with a low-demand physical activity requirement
represents a situation that is often best handled by non-operative
means, whereas the opposite would be the case for a high-grade
instability in the face of a high-demand physical activity requirement.
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FIGURE
5 - Skiing, skating and
roller-blading represent "in between" risk activities
for someone with a torn or loose ACL. Treatment with bracing
alone may or may not suffice, depending on a host of factors
including how strong your leg muscles are and how extreme
your participation level is. Remember, even a totally healthy
ACL will not necessarily prevent a knee injury if you take
a fall. |
If you are in an in-between or "middle of the
road" situation (see FIGURE 5),
another factor worth considering relates to the timing of surgical
treatment. Anterior cruciate ligament tears that are reconstructed
fairly early on following injury (within the first six to twelve
weeks or so) tend to achieve a slightly more stable and successful
result with surgery than those knees that have been loose a long
time and whose secondary ligamentous constraints (remaining knee
ligaments) have been stretched out by recurrent giving-way episodes.
Several surgical researchers have observed that an anterior
cruciate ligament injury that is treated sooner rather than later
has perhaps a 5% to 10% better prognosis for a successful surgical
restoration of ligament stability than an anterior cruciate ligament
injury that is treated in a delayed fashion, after the instability
condition has been allowed to become chronic. For someone
who is in a situation where both non-operative treatment
and operative treatment would appear to be reasonable, this slightly
different prognosis for the results of acute (early) versus chronic
(late) surgical treatment may become the "tie breaker"
that leads the patient to opt for surgical management at the outset.
An additional factor that must be weighed in the decision-making
process is the status of the various other knee joint structures.
When other knee ligaments are torn along with the ACL it may be
more desirable to rebuild the ACL than otherwise. The presence
of surgically repairable knee cartilage (meniscus) tears also
favors ACL reconstruction because repaired menisci generally
heal better and last longer when the ACL is fixed at the same
time.
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FIGURE
6 - A patient's age may be of little importance in
deciding whether or not to have a torn ACL rebuilt. A physically
active, 55-year-old may benefit more from ACL reconstruction
than a sedentary 20-year-old! |
Interestingly enough, age by itself is of little
importance in deciding whether or not to have a torn anterior
cruciate ligament reconstructed. All other things being equal
(i.e., similar activity level and grade of knee instability),
a patient between 40 and 60 may be just as good a candidate
for surgery as someone in their twenties. A patient's age,
however, may affect the particular surgical technique that is
best suited for them.
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