KNEE
REHABILITATION AFTER SURGERY
Tankersley WS, Mont MA, Hungerford DS:
In: Rehabilitation Secrets. Young MA, O'Yang B, Steins SA,
(eds). Hanley
and Belfus, Mosley, Philadelphia,
1997.
1.
Define knee arthroplasty.
A
knee arthroplasty is a replacement of damaged or arthritic
surfaces of the distal femur and proximal tibia and the rest
of the knee joint with metal and plastic materials to restore
the integrity of the joint.
2.
What are the the indications for this procedure?
The
main indication is to relieve pain caused by arthritis. Secondary
goals are to correct deformity, and to restore function. More
specifically, canidates for knee replacements have severe
degenerative changes of their knee joint seen on radiographs
and have failed multiple methods of nonoperative treatment
to relieve their pain. These methods include anti-inflammatory
medications, the use of a cane, decreased activity, loss of
weight when indicated, as well as interarticular corticosteroid
injections. These methods should be tried 3-6 months before
a knee arthroplasty.
3.
How many knee arthroplasty procedures are performed in the
United States annually?
Approximately
150,000.
4.
What are the goals of knee arthroplasty?
- To
restore a painfree joint
- To
restore range of motion (ROM)
- To
allow function that approaches normal for a patient
5.
How successful are these operations?
About
95-97% of patients can expect a good to excellent clinical
result. This clinical result encompasses minimal to no pain,
the ability to walk > 1 mile, increased ROM, and patient
satisfaction with the procedure. These results generally hold
up 5- and 10-year follow-ups, with about a 1% failure rate
per year. Thus, one can expect about 90% success with these
procedures at 10 years.
6.
How long does significant pain last after knee surgery?
Most
patients know within 1 or 2 days after surgery that their
pain is markedly different than preoperatively. The arthritis
pain is typically eliminated immediately. The surgical pain
lasts for 2-3 weeks but progressively gets better after the
first 1-2 days.
7.
When should a knee manipulation be seriously considered?
If
you have only 70° flexion by 14 days postoperatively.
8.
Since the continuous passive motion machine does not appear
to affect long-term ROM, why should one use it in a patient
with total knee replacement?
It
may be cost effective. It improves knee flexion and may reduce
the number of hospital days and frequency of manipulations.
9.
Can patients return to playing sports after knee surgery?
Most
patients can return to low-impact sports, such as golf, doubles
tennis, and bowling, walking, and use such exercise machines
as a stationary cycle and cross-country ski simulators. High
impact exercises such as running, singles tennis, basketball,
volleyball, and football should be avoided as these may lead
to undo wear and tear on the prosthesis.
10.
Describe a general rehabilitation program in a patient with
total knee arthroplasty (TKA).
Day
of surgery
- Deep
breathing exercises
- Active
ankle ROM
Postop
day 1
- Lower-limb
isometrics including quadriceps, hamstrings, and gluteral
sets
- Wearing
a knee immobilizer until the development of active knee
enstensionand demonstration of good leg control during
ambulation
- Weight-bearing
after TKA may be partial or full, depending on the
surgeons discretion
Postop
day 2
- Standing
at the bedside with knee immobilizer and partial weight-bearing
on the operated limb
- Active
assisted ROM
Postop
day 4
- Progressive
isotonic and isometric knee and hip muscle strengthening
- Concentrate
on terminal knee extension through active knee extension
exercises
11.
How long will a total knee replacement last?
Although
this will vary from patient to patient, many large series
in orthopedic literature show continued good to excellent
results in > 90% of patients at 10 years
12.
When will the patient receive full benefit after knee arthroplasty?
Typically,
by 3 months, the patients are doing quite well. Usually, by
that time, they have regained most of their strength across
the joint as well as ROM. They continue to improve throughout
the first year after surgery, and by 1 year, the patient has
achieved full benefit from the operation.
13.
How should a patient ambulate stairs after knee surgery?
When
going up stains, the patient leads with the nonoperative extremity
and then follows with crutches and operative extremity, taking
one step at a time. When descending, the patient leads crutches
and the operative extremity, following with the nonoperative
extremity.
14.
Is prophylaxis for deep venous needed after knee surgery?
Yes.
15.
List the usual sequence of ambulatory aids given to patients
after total knee replacement.
- For
the first day or two, the patient usually works in physical
therapy on the parallel bars.
- He
or she is then progressed to crutches or a walker for
the first 6 weeks.
- The
patient is then advanced to one crutch or cane, which
is continued for an additional 6 weeks.
- Most
patients (70%) are ambulatory without an assistive device
by 3 months
16.
What are four goals of an occupational therapy after total
knee replacement?
- To
reestablish basic activities of daily living (ADL), with
modifications that keep the patient's ROM within restrictions
- To
teach joint protection
- To
review for falls risk
- To
provide equipment with training.
17.
Is sex possible after knee replacement?
Provided
it does not involve chasing your partner around the room (or
other obstacle-laden course) at high speeds.
18.
When can patients bear full weight after knee surgery?
Most
patients are kept on partial weight-bearing (50%) for 6-8
weeks, with progression to full weight-bearing usually at
the end of 6 weeks. For biologic fixed components, full weight-bearing
may not be allowed until 12 weeks to ensure bone ingrowth.
19.
What muscles should be targeted after knee surgery?
The
muscles most affected by surgery are the quadriceps
muscles (vastus lateralis, vastus medialis, vastus intermedius,and
rectus femoris). Isometric strengthening and active ROM should
begin immediately after surgery. For the first 6 weeks, the
quadraceps should be strengthened with isometric exercises.
Then, progressively resisted isokinetic or isotonic strengthening
be added. Other muscles that act at the knee through the open
and closed kinetic chains should be strengthened: hamstrings,
gastrocsoleus, and ankle dorsiflexors.
20.
How should knee range of motion be measured and recorded?
ROM
should be measured from the lateral side of the patient's
leg with a goniometer. Full extensioni.e., an angle
between the femur and the tibial shaft of 0°--should be
recorded as 0°. The knee is then brought to full flexion
and measured again from the lateral side of the patient's
knee, and this is recorded as a positive number, somewhere
between 0-135°. If the patient's leg cannot be fully extended,
i.e., lacks 10° of complete extension, this should recorded
as +10 extension and the flexion recorded as whatever the
patient is able to flex past that number. For example, the
patient flexing to 100° but lacking complete extension
of 10° should be recorded as having an ROM +10-105°.
If the patients knee comes to hyperextension, then the
amount past 0° should be recorded as a negative number.
For example, if the subject hyperextended approximately 5°
and flexed to 100°. the ROM is recorded as 5--100°.
21.
After total knee replacement, what should be the expected
range of motion for the patients knee? What are the preliminary
goals?
The
biggest predictor of postoperative ROM is preoperative ROM.
The average postoperative ROM is 105°-110° for most
patients. At least 90° of ROM is desirable for a good
functional outcome. It is hoped that at least 90° of motion
will be obtained within the first 7-10 days after surgery.
22.
What is meant by the term "extensor lag"?
With
an extensor lag, the patient cannot actively extend to a completely
straight position (angle of 0° measured between the femur
and tibia). Passive extension is not limited however. This
condition occurs because of a lengthening or weakening of
the quadriceps after surgery or because of prosthetic component
positioning.
23.
What is meant by the term "flexion contracture"?
This
term is applied to patients who cannot fully extend the leg
either actively or passively. This condition is usually caused
by a mechanical block, such as retained osteophyte, scarring
of the posterior capsule or posterior structures, extremely
tight hamstrings or malposition of the prosthetic components.
A flexion contructure significantly increases the energy required
for ambulation.
24.
How do you check stability of the knee after a knee replacement?
Medial/lateral
testing (varus or valgus):
The knee is checked throughout the ROM starting at full extension
and then proceeding to 30°, 60°, and 90°. At each
position, the patient's leg should stressed medially and laterally.
Any opening or closing of >5° should be considered
excessive.
Anterior
and posterior testing: Again, the knee is checked throughout
the ROM with Lachman's or anterior Drawer test,
and the position of the greatest instability is recorded.
This displacement is normally 5-8 mm of anterior translation,
as the anterior cruciate ligament has been sacrificed in all
total knee replacements.
25.
Should the physiatrist be made aware of any particular circumstances
after knee surgery?
The
physiatrist should be aware if the patient has had any surgical
procedure performed in addition to the routine surgical exposure.
These adjuncts may include a quadriceps muscle turndown,
performed by splitting this muscle in an oblique fashion to
allow the patella to be retracted distally, for better exposure
of the joint. In addition. a tibial tubercle osteotomy
sometimes performed to allow exposure of the joint; it is
performed by reflecting a portion of the bone underneath the
tibial tubercle with the attached patella tendon laterally
and then repairing this with some form of internal fixation.
In either case, the ROM may be altered after surgery, and
the strengthening part of rehabilitation may be delayed allowing
the tendon or bone to heal.
26.
Are resisted concentric exercises important after knee replacement
surgery?
Concentric
exercises against resistance should be avoided for the first
6-8 weeks. During that time, the patient can perform isometric
and active ROM exercises against gravity. After the first
6-8 weeks, resisted open kinetic chain strengthening can start
in the place of joint motion with 1-10 lbs. Exercises performed
with heavy weights against resistance cause undue wear and
tear on the prosthetic components.
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