Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Navigation
Abstract number: 24590
PERIOPERATIVE KNEE NAVIGATION - SIMPLE AND PRECISE TECHNOLOGY
Evgeny MALYSHEV 1 , Dmitriy PAVLOV 2 , Svyatoslav KOROLYOV 1 , Sergey BLINOV 1
1 Nizhniy Novgorod Medical Academy, Nizhniy Novgorod (RUSSIA), 2 Nizhniy
Novgorod Research Institute of Traumatology and Orthopaedics, Nizhniy Novgorod
(RUSSIA)
INTRODUCTION: Intraarticular fractures and mal-union, osteoarthritis, congenital
pathology etc. cause frontal plane angle deformity (varus and valgus) in the knee
which is a common malalignment. Precise clinical measurement of this deformity is a
challenging problem. METHODOLOGY: A simple and precise tech-nology is offered
to solve this problem with trigonometric function: = arctg BC/AB × 180º/, where AB is
length of the shin (cm) and BC is deviation of the ankle (cm). Three points for leg axis
assessment are used: spina iliaca anterior superior, the middle of patellar tendon on
the level of its lower pole and tendon of tibialis anterior muscle on the level of ankle
joint line with dorsal flexion. In preoperative and postoperative examination we use
original device consisting of two perpendicular rulers 1 meter and 30 cm long. To
simplify the calculation of deformity angle, a table of most common parameters from
30 to 45 cm of the shin length and up to 10 cm of ankle deviation is used.
Intraoperative assessment is performed with a cable method; deviation of ankle joint
is estimated by sterile stainless steel ruler. Comparison with radiological examination
has revealed that the mistake of measurement is within ±0.5°. CONCLUSION: There
are some indications to apply our technology in perioperative period which are as
follows: preoperative planning of corrective osteotomy; measurement of physiological
varus and valgus to approximate the fractured leg to the contralateral limb or to
correct the axis of the extremity if monocompartmental osteoarthritis development is
ex-pected; intraoperative confirming of fracture reduction, adequacy of correction in
osteotomies, accuracy of knee prosthetic components settings; control of weightbearing
in intraarticular fractures for early diagnosis of secondary bone fragments
displacement in postoperative period; evaluation of outcomes after intraarticular knee
fractures; estimation of medial-lateral instability in the knee joint.
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