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Acute ruptures of extensor mechanism
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Traitement
An acute surgical repair gives the best results
[7]. Many surgical techniques have been
described.
In case of mid-body quadriceps tendon tear, an
anatomical end-to-end suture with non
absorbable sutures gives very good results. A
median vertical incision is done. The peritenon
is incised and the hematoma is cleaned. The
tendon stumps are identified. A n° 2 absorbable
suture is passed transversally in each stump,
2cm from the tear. Three “U” sutures are done
with a nonabsorbable suture (n° 2 Fiberwire).
Sutures are tightened with the knee extended
and are reinforced by multiple single stitches
with absorbable sutures (n° 0 Vicryl) [18].
When the tear occurs at the osteotendinous
junction, a median vertical incision is done at
the proximal border of the patella to expose the
tear. Necrotic or frayed tissues are debrided.
Four 2.5 mm transosseous tunnels are done
obliquely in the proximal border of the patella.
Three “U” nonabsorbable sutures (Fiberwire or
Mersuture) are passed through the tunnels and
in the quadriceps tendon stump. Knots are done
with the knee in extension. Another technique
is to baste the proximal tendinous stump with
non-absorbable sutures (Krackow-type sutures
[12]) which are then passed through vertical
transosseous tunnels in the patella. The suture
is reinforced by multiple interupted absorbable
sutures (n° 0 Vicryl). If torn, the retinacula
must also be sutured [18].
After surgery, a 30° knee brace is worn for rest
and walking is allowed with a 0° knee brace for
6 weeks. It is mandatory to protect the sutures
while the tendon is healing. Passive knee
flexion is progressively increased: 0-45° from
day 0 to day 15; 0-70° from day 16 to day 30;
0-90° from day 31 to day 45. Full flexion is
allowed after 6 months.
Quadriceps amyotrophy is very frequent and
difficult to recover in spite of physiotherapy.
However, it may not have significant
consequences in daily living [23]. Isometric
contractions and electrostimulation may
prevent this amyotrophy. A secondary rupture
can happen but is rare [20].
In case of a delayed diagnosis, repair is more
difficult as the quadriceps is retracted and an
end-to-end repair is not possible anymore. In
such cases, surgical reconstructive techniques
have been described: interposition of a tendinous
auto- or allograft, tendinous advancement flaps,
etc. Results are worse in case of delayed repair
or reconstruction and complications rate is
higher [13]. Early diagnosis and treatment are
mandatory to achieve a good healing and
functional recovery.
Acute patellar
fractures
Anamnesis and incidence
Fractures of the patella are more frequent than
quadriceps or patellar tendon ruptures. They
are due to a direct trauma (fall on the floor with
impact of the patella, road accident with direct
trauma) or rarely indirect trauma (violent
eccentric contraction of the quadriceps while
the knee is flexed). In case of car road accident,
an associated posterior cruciate ligament tear
and ipsilateral hip fracture must be looked for.
Many types of patellar fractures exist: longitu
dinal or transversal, displaced or not. Only the
transversal and displaced fractures interrupt the
extensor mechanism [16]. In situ transversal
fractures and longitudinal fractures (displaced or
not) do not interrupt the extensor mechanism.
Diagnosis
Clinical examination of a patient with a
transverse displaced fracture of the patella
reveals an inability to actively extend the knee,
pre-patellar swelling which is the fracture
hematoma. The skin overlying the patella has
been contused during trauma and may be
stretched out by this hematoma, sometimes
leading to necrosis. This must absolutely be
prevented by early surgical management of the
fracture.