Læknablaðið - 15.03.1990, Side 58

LÆKNABLAÐIÐ 1990; 76: 177
177
NÝR DOKTOR í LÆKNISFRÆÐI -
JÓN KARLSSON
Þann 8. maí síðastliðinn lauk Jón Karlsson
læknir doktorsprófi frá Gautaborgarháskóla.
Ritgerðin nefnist á frummálinu: »Chronic
Lateral Instability of the Ankle Joint. A
clinical, radiological and experimental study«.
Hér á eftir fer útdráttur úr ritgerðinni:
Ankle joint instability can be defined as
either functional or mechanical instability.
Functional instability is the most common
residual disability after lateral ligament
injuries. A correlation was found between
good functional results and mechanical
stability both in patients treated with Evans
reconstruction and anatomical ligament
reconstructions. Long term results after Evans
reconstruction were unsatisfactory in 50%.
In patients treated for chronic lateral ankle
instability with anatomical reconstruction
a satisfactory result was found in almost
90%. Two different techniques based on
the same surgical principle were used for
anatomical reconstructions. Restoration of
mechanical stability is a primary factor in
the treatment of chronic lateral ankle joint
instability. A better result was found if both
the anterior talo-fibular and the calcaneo-
libular ligaments were reconstructed. Patients
with generalized hypermobility of the joints,
long-term Iigamentous insufficiency and those
previously operated upon with tenodesis
should be considered as poor risks when
anatomical ligament reconstructions are
planned. Complications were few in patients
treated with anatomical reconstructions
compared witli those treated with Evans
reconstruction. The anterior talar translation
and talar tilt were significantly higher in
functionally unstable ankle joints than in
a control group with stable ankle joints.
There was also significant difference
between functionally stable and unstable
ankle joints regarding both anterior talar
translation and talar tilt in patients with
unilateral functional instability. Evaluation
of mechanical instability is therefore of value
in the diagnostic and therapeutic evaluation of
ankle joint instability. A scoring scale based
on the patients subjective and functional status
can be used to evaluate ankle joint function.
The scale correlates statistically with both
anterior talar translation and talar tilt. The
reaction time for both the peroneus longus and
the peroneus brevis muscles was significantly
longer in unstable than in stable ankle joints.
With biomechanical analysis it was shown
that receptor stimulation occurs at a constant
fraction of the talar tilt angle.