Coronal alignment of the knee is defined by the hip-knee-ankle angle
(HKA), the femoral mechanical angle (FMA), the tibial mechanical
angle (TMA), and the joint line convergence angle (JLCA). To date,
there is still a lack of knowledge about the variability of native
coronal knee alignment. The purpose of this paper is to present a
systematic review of the current literature about the
variability of coronal knee alignment (HKA, FMA, TMA, and JLCA) in
The electronic databases MEDLINE, EMBASE, and Google Scholar were
searched from database inception to search date (November 1, 2018)
and screened for relevant studies. The PRISMA guidelines were
followed. Inclusion criteria were studies that reported the coronal
alignment of the native, non-osteoarthritic knee.
A total of 15 studies met the inclusion criteria. Thirteen studies
performed the measurements on weight-bearing long-leg standing
radiographs (LLR), one study used MRI, and one study used the EOS
imaging system. The mean HKA ranged from
176.7° ± 2.8° (male) to 180.7°
(female). The mean FMA ranged from
92.08° ± 1.78° (female) to
97.2° ± 2.7° (female). The mean TMA ranged
from 84.6° ± 2.5° (female) to 89.6°
(female). The mean JLCA ranged from
- 0.47° ± 0.98° (male) to
- 1.9° ± 1.4° (female).
LEVEL OF CLINICAL EVIDENCE
This systematic review provides a detailed overview about the
variability of the coronal knee alignment in non-osteoarthritic
knees. The broad variability of all coronal alignment parameters
highlights the necessity for a more anatomic and individualized
approach in knee arthroplasty. It also offers the fundament to
understand the changes in osteoarthritic knees.
Systematic review, Level IV.