Notas / Notes - Active Congress.......

VIERNES / FRIDAY
202
culture in a inflammatory stage. If no germ can be identified
by aspiration only the clinical course together with the analysis
of WBC and C-reactive protein may help differentiate between
infection and aseptic arthrofibrosis. However, a low grade
infection (if this condition exists) may mimic arthrofibrosis.
Complex regional pain syndrome (CRPS) is a description
created by the IASP (International Association for the Study
of Pain) for an inflammatory disease after surgery or trauma
which summarizes the terms algodystrophy, reflex sympathetic
dystrophy, M. Sudeck, causalgia and others. CRPS I is associated
with nerve damage during surgery, and CRPS II is
not. Ethiopathology is not well understood, but in both cases
the sympathetic (autonomous) sensory and motor nerve
system is disturbed. The symptoms of acute arthrofibrosis
as a consequence of CRPS consist of pain at rest, which can
range between moderate and severe, hyperalgia, dysaesthesia
and skin temperature dysregulation. The skin of the index
knee can be colder (in 20% of the cases) or warmer (in 80%
of the cases) than the contralateral knee. Skin color turns
into red because of increased vascularisation, or it can be
pale and cyanotic if skin vascularisation is decreased. Hyperhydrosis
may predominate (50% of the cases) over hypohydrosis
(20% of the cases).
TREATMENT OF ARTHROFIBROSIS OF BIOLOGIC
ORIGIN IN THE ACUTE STAGE
Any surgical intervention is obsolete during acute stage of
arthrofibrosis. Diminution of inflammatory clinical signs are
the goal of initial conservative treatment. Mild physiotherapy
to maintain mobility but without forcing the knee into a painful
arc of motion is mandatory. The author has made good experiences
with alternative treatments such as Osteopathic
treatment or acupuncture which focus on the autonomic nerve
system. An invasive approach to block the autonomic
nerve system consist of lumbar sympathetic blocks. Blockage
of the sympathetic nerves can also be performed with spinal,
epidural, or peripheral nerve block, but relief of pain after a
lumbar sympathetic block will most clearly delineate the
cause of pain as sympathetically mediated. Most fibers
headed for the lower extremity pass through the second and
third lumbar ganglia, so that a sympathetic block with 10-15
ml epivacain 1% or bupivacain 0.5% placed at this level provides
almost complete sympathetic denervation of the afferent
nerve fibers of type C to the lower extremity. Clinical effectiveness
is only achieved after several injections at an interval
of a few days. If the patient is unwilling to be treated by
multiple injections, blockage of the sympathetic system can
also be achieved by continuous administration of Ropivacain
0.2-0.3% 6-12 ml per hour with Clonidin 3um per ml and/or
fentanyl 2ug per ml through a lumbar catheter. With the advent
of special lumbar catheters a long term treatment of 2-
3 weeks is possible. Additional oral pain medication with
non-steroidal anti-inflammatory drugs, paracetamol and
opioides are always indicated.
Manipulation under anesthesia (MUA) in an acute stage is
a controversial procedure, which can accentuate inflammation.
In the absence of inflammatory signs, examination under
anesthesia for painful reduced motion in the early postoperative
phase may help to differentiate between decrease
flexion as a consequence of mechanical block or pan-induced
decreased flexion. Examination under anesthesia may be
followed immediately by true MUA if the knee feels “soft” and
flexion increases applying gentle force.
TREATMENT OF ARTHROFIBROSIS OF BIOLOGIC
ORIGIN IN THE CHRONIC STAGE
During the inflammatory stage any aggressive procedure is
counter-productive as it will induce inflammation. This is true
for closed and open manipulation. Closed manipulation under
anesthesia can be effective but only if the inflammatory level
is low. Patients with posterior stabilized knees respond better
to closed manipulation. Knees with posterior cruciate sparing
prosthesis have usually a short and tight PCL which can not
be stretched during manipulation without harming the polyethylen.
In addition the distal femur may be in risk of fracture
in such cases. Patients with long lasting stiffness, at least 8
weeks after primary total knee replacement, arthrotomy is
the treatment of choice. A technetium bone scan helps making
the decision whether the arthrofibrosis is still an acute
stage or whether surgery is safe in a stage where inflammation
processes have markedly decrease or have completely disappeared.
At arthrotomy, a complete synovectomy is performed,
starting with the obliterated suprapatellar pouch where
the quadriceps tendon is scared down to the femur. The
quadriceps is liberated, the medial and lateral gutters are
reconstructed, and a lateral release is performed to increase
patellar mobility. If the knee can not be exposed properly it
is safer to performe an osteotomy of the tibial tubercle. This
prevents avulsion of the patellar tendon which is a catastrophy
with poor result. It is mandatory to resect the PCL and to
remove the polyethylen insert for better debridement of the
posterior aspect of the knee. Usually the posterior capsule
stays tight enough to resist subluxation without the need to
revise to a posterior stabilized knee. Trial inserts should be
available for stability judgment at the end of surgery. It is
preferable to increase intrinsic stability of the knee with an
anteroposterior lipped insert if the system allows it (Fig. 1).
A poor result will be achieved with synovectomy and isolated
polyethylene insert exchange if a mechanical problem such
as component malposition or oversizing is the source of
limited motion. If there is any doubt at trial reduction that stability
will seriously be compromised, revision to a higher constrained
knee such as CCK might be considered (Fig 2). In
selected cases the collateral ligaments need to be scarified
and revision will only be successful with rotating hinge total
knee in order to establish femortibial stability. Therefore,
good preoperative judgment of postoperative stability patterns
is needed in order to plan for panning the appropriate implant.
Pain management as mentioned above is essential after surgigal
intervention, but also after MUA. The goal is to achieve
at least 90° of flexion. In general, if the patient starts with far
less flexion than 90° and he achieves an arc of motion that
goes somewhat beyond 90° of flexion, sometimes even to
100 or 110°, he usually is satisfied and the intervention was