Transcript Document

“ALTERED GAIT SYNDROME”
MYTH OR REALITY?
Alexander Sapega, M.D.
New Jersey / PA Knee & Shoulder Centers
THE “SHORT” ANSWER:
• Altered Gait
Reality
• “Syndrome”
Myth
THE “LONG” ANSWER:
Pretty much the same as
the short answer, but with
a few “complexities”
COROLLARY QUESTION:
Can a problem in one knee cause
symptoms in its mate?
“SHORT” ANSWER:
NO!
“LONG” ANSWER:
NO!
(except in special circumstances)
PATIENT:
“My good knee began hurting
because of my bad knee.”
WHY DO PHYSICIANS HEAR
THIS TO SO OFTEN?
REASON #1
• First knee problem does often
make patients modify their gait
to some extent.
REASON #2
• Patients’ worry and
concern over their first
knee problem makes them
acutely attuned to even the
slightest discomfort in their
other knee
REASON #3
• Most people over 40 with a
symptomatic degenerative
condition in one knee also have
an asymptomatic one in their
opposite knee, which can become
symptomatic at any time….
and when it does, most patients
will intuitively assign blame to
the first knee!
UNDERSTANDING NORMAL
GAIT
“I have been bearing more weight
on my good knee because of my
bad knee.”
IS THIS REALLY TRUE?
THE HUMAN KNEE
WAS BUILT TO
ROUTINELY
HANDLE 100% OF
BODY WEIGHT
(it’s “all-natural”)
THE ONLY WAY
ONE CAN REALLY
“BEAR MORE
WEIGHT” THAN
NORMAL ON A
KNEE IS TO PICK
UP A LOAD AND
CARRY IT!
“DYNAMIC” vs. “STATIC”
ANALYSIS:
Accounting for inertial forces by
way of biomechanical:
GAIT ANALYSIS
SO WHAT CAN WE LEARN
FROM GAIT ANALYSIS
STUDIES?
• Absolute load
• Loading rate
• Support time during
stride cycle
CONTEXT: “LIMPING”
(Favoring/Dis-Favoring)
• Paralytic Limp
• Short Leg Limp
• Antalgic Limp (pain on one side)
ABSOLUTE PEAK KNEE
LOAD IS RELATED TO:
• Body Weight
• Stride Length
• Gait Speed
KNEE
LOAD
GAIT SPEED
KNEE PAIN CAUSES:
• Shorter stride length
• Slower gait
LOWER LOAD ON
BOTH KNEES!
KNEE PAIN / LIMP DOES
NOT CAUSE:
• Significantly higher peak
load in the opposite knee
(at any given gait velocity)
Messier, et al: Arch. Phys. Med
& Rehab. 1992
KNEE PAIN / LIMP DOES
CAUSE:
• Modest increase in loading
rate of opposite knee, a
benign phenomenon
Messier, et al: Arch. Phys. Med. &
Rehab. 1992
KNEE PAIN / LIMP DOES
CAUSE:
• Slight prolongation of time
spent by opposite knee in
stance phase of stride cycle
(support time, or “duty
cycle”)
Harrington: British J. Bone &
Jt. Surg. 1984
“DUTY CYCLE” EFFECT ON
OPPOSITE KNEE
( loading time during gait)
vs.
ACTIVITY LEVEL EFFECT
ON OPPOSITE KNEE
( total load time and often
amount of load)
KEY POINT!
LIGHT DUTY / NO DUTY CAN:
• Reduce the amount of load,
and
• Reduce total loading time
seen by opposite knee, despite
antalgic gait.
SUMMARY OF KNEE PAIN
EFFECT ON OPPOSITE LEG:
• Slower gait & shorter stride REDUCE LOAD
• Antalgic Gait
No significant in load but
• Light / No Duty
slight in loading rate and
duty cycle
Lower total loading time &
often lower load
USE OF CRUTCHES CANE:
• No increased load
•
or known adverse
effect on opposite
leg/knee
(shoulders =
different story!)
NET EFFECT OF A KNEE
PROBLEM THAT CAUSES
GAIT CHANGES AND A
DECREASE IN ACTIVITY
LEVEL:
opposite knee almost always sees
less total overall work-load, not
more!
SPECIAL
CIRCUMSTANCES:
• Frequent stair-climbing with one
leg only
patellofemoral
overuse syndromes
• Knee buckling
FALL
which injures opposite knee
“In the days when limping from
poliomyelitis was common, complaints
in the opposite leg attributable to
limping were unknown. In fact, the
commonest complaint related to
limping was backache, not pain in the
normal leg.”
Harrington, 2005 / Burke et al, 1978
TAKE HOME POINT:
“Altered Gait Syndrome”
with very few exceptions,
is nothing more than a
modern “Urban Legend”
THANK YOU !
NJ / PA Knee & Shoulder Centers
Mt. Laurel, NJ
*
Havertown, PA