In the pregnant women in our survey, the prevalence of RLS was found to be 19.9%, which is higher than the prevalence of RLS that has been found in the general public in a previous study. This suggests that RLS-related sleep problems may be an important public health issue among pregnant women in Japan. This finding may have implications for attempts to improve sleep hygiene in this group.

The intercondylar notch was significantly narrower in subjects with bilateral ACL injuries than in healthy subjects. NWI measurement using coronal MRI is useful for judging intercondylar notch narrowing. The risk for ACL injuries is very high when NWI is ≤0.25. Preventive measures for the unaffected knee are required for patients with a narrow intercondylar notch.

This study identified previous history of fracture and remnants of internal fixation as major risk factors of infection after TKA. For clinical relevance, surgeons should be aware of potential infection when performing TKA in patients with these risk factors and patients should be informed of the potential risks.

Concentrated rehabilitation at a rehabilitation hospital after ACL reconstruction has the potential to improve muscle strength in the lower extremities more dramatically in the early stages of post operation. However, the initial benefits of intensive physiotherapy disappear after 6 months.

For clinical relevance, soft tissue release and osteophyte resection around the patella, lateral femoral condyle and posterior medial femoral condyle might be indicated to obtain a higher degree of knee flexion angle.