Abstract
The anterior tibial artery (ATA) is the most critical anatomical structure at risk
at the distal border of the posterolateral approach to the tibial plateau. This study
aimed to use available lower extremity digital subtraction angiography (DSA) images
to determine the distal safe limit of this approach by measuring the distance from
the tibial joint line to the ATA where it pierces the interosseous membrane. Tibial
plateau mediolateral width (TP-ML-W) and the perpendicular distances from the ATA
to the tibial joint line and fibular head were measured on DSA images in 219 lower
extremities. To normalize the distances according to the tibial dimensions, each distance
was divided by the TP-ML-W, and a ratio was obtained. Popliteal artery branching pattern
was categorized according to the classification proposed by Kim et al. Comparative
analysis between right and left extremities, genders, and anatomical variations were
performed. There were 102 male and 26 female subjects with a mean age of 60.7 ± 15.7
years (range, 17–92 years). Ninety-one subjects had bilateral lower extremity DSA;
thus, a total of 219 extremities were analyzed. The TP-ML-W was wider in male (78.3 ± 7.0)
than female (70.5 ± 7.3) subjects (p = 0.001). The ATA coursed through the interosseous membrane at 50.9 ± 6.9 mm (range,
37.4–70.2 mm) distal to the tibial plateau joint line, and it was 66.5 ± 7.2% of the
TP-ML-W. The ATA coursed through the interosseous membrane at 36.5 ± 6.0 mm (range,
21.9–53.8 mm) distal to the fibular head, and it was 47.7 ± 6.6% of the TP-ML-W. All
measured variables were similar between the regular branching pattern of the popliteal
artery (type 1A) and other observed variations among male subjects. The safe length
of dissection in the posterolateral approach is average 66.5% (range, 45.7–86.7%)
of the TP-ML-W. This ratio is valid for both genders. The use of a ratio instead of
a distance, which is subject to personal variations, seems to be more logical and
practical for planning this surgery, but the wide range should still not be ignored.
Keywords
posterolateral approach - knee - popliteal artery - anterior tibial artery
