Does alignment in people without osteoarthritis differ by age and sex?

Mean HKA was 178.01° in males and 178.82° in females. Mean MPTA in males was approximately 1° smaller.

Varus alignment greater than 3° was present in 16.9% of the 18–19-year group and 38.0% of the 60–69-year group.
The Knee (2023). DOI: 10.1016/j.knee.2023.09.009 · Original explanatory chart based on reported data
Evidence & Original Source Image use terms

The research question

Participants and Methods

Standing full-leg radiographs from healthy volunteers aged 18–69 were reviewed retrospectively. HKA, LDFA, MPTA, JLCA and femoral bowing were compared by age and sex. The analysis included 1,452 limbs: 670 male and 782 female. Limb counts must be distinguished from patient counts.

Main Findings

Mean HKA was 178.01° in males and 178.82° in females. Mean MPTA in males was approximately 1° smaller. Varus greater than 3° was present in 16.9% of those aged 18–19 and 38.0% of those aged 60–69. Age-group differences were more apparent in femoral parameters, while tibial alignment was relatively constant.

Implications for clinical and surgical practice

These data can inform estimates of pre-arthritic alignment in individual surgical planning. Group means should not be used as a uniform target angle for all patients.

Limitations

This cross-sectional analysis compared age groups; it did not directly follow age-related alignment changes in the same person. The data are from healthy Korean volunteers and do not represent all ethnic groups or surgical targets for patients with OA.

Let's put it briefly.

Which clinical question does this address?

These data can inform estimates of pre-arthritic alignment in individual surgical planning. Group means should not be used as a uniform target angle for all patients.

Keywords

Kinematic alignment
Lower limb alignment
Mechanical alignment
Normal alignment
Total knee arthroplasty
Genu Varum
Osteoarthritis, Knee
Child

Abstract · Original text

Doohyun Hwang, Min Wook Choi, Seong-Hwan Kim, Hyuk-Soo Han, Chong Bum Chang, Myung Chul Lee, Na-Kyoung Lee, Du Hyun Ro. Age and sex differences in coronal lower extremity alignment in a healthy Asian population. The Knee. 2023;45:198-206. doi:10.1016/j.knee.2023.09.009.

BACKGROUND

The purpose of this study was to analyze the coronal alignment of lower extremities according to age and sex in a healthy population and demonstrate the differences.

METHODS

Standing full-lower limb anteroposterior (AP) radiographs of healthy volunteers (670 males and 782 females) aged 18-69 years were retrospectively analyzed. The hip-knee-ankle angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), joint line convergence angle and femoral bowing angle (FBA) were measured. The radiographic parameters were compared according to groups of age and sex. The proportion of volunteers with varus or valgus alignment more than 3° were also analyzed.

RESULTS

With increasing age, HKA and LDFA varus increased. With increasing age, femoral medial bowing decreased. In addition, the HKA showed more varus alignment in males than in females (178.01° vs. 178.82°, P < 0.001). The MPTA was about 1° smaller in males than in females (P < 0.001). The proportion of patients with varus alignment of more than 3° increased with increasing age, with 16.9% in the 10-19 years old and 38.0% in the 60-69 years old groups.

CONCLUSION

This study demonstrated that males showed more varus tibial alignments than females. Varus limb alignment, LDFA, and FBA also increases with age. In contrast, tibial alignment was constant across all age groups. Therefore, differences in lower extremity alignment according to age and sex should be considered in estimating individual prearthritic alignments.

Read abstract on PubMed

The original paper.

Age and sex differences in coronal lower extremity alignment in a healthy Asian population

Doohyun Hwang, Min Wook Choi, Seong-Hwan Kim, Hyuk-Soo Han, Chong Bum Chang, Myung Chul Lee, Na-Kyoung Lee, Du Hyun Ro
The Knee · 2023

DOI · 10.1016/j.knee.2023.09.009 PubMed Based data

Academic Discussion

Results explained with study numbers