Tanaka T, et al. – Study authors attempted to comparatively investigate the usefulness of the hip–calcaneus (HC) line and hip–ankle (HA) line for the evaluation of lower–limb alignment in healthy people and in patients with osteoarthritis (OA). They observed that the HC line of the lower limb differs from the HA line. They suggested that single– and double–leg stances should also be considered, particularly in patients with OA. These considerations might affect preoperative planning for high tibial osteotomies and TKA.

Methods

• 34 healthy people (mean age, 26.4 years) and 34 patients with OA (mean age, 74.2 years) were included for this investigation.
• After that, frontal radiographs of the entire lower limb were taken in single- and double-leg stances.
• The hip–knee–ankle (HKA) and hip–knee–calcaneus (HKC) angles were evaluated and compared within and between stances for each group.
• Finally, the HA line and HC line were assessed as the passing line in the knee, and were similarly compared.

Results

• They observed significant differences between the HKA and HKC angles, and between the HA line and HC line in both groups during both stances.
• They also found significant stance-related differences in the HKA and HKC angles, HA line, and HC line in the OA group, but not in the healthy group.