Roger Federer has retired, mostly due to his knee. This is tragic but extremely common and often avoidable. Here is how.
Federer to miss French, US Open over knee surgery; will return in 2021
Steph Curry's Knees
Roger Federer out until 2021 after having another knee procedure
Roger Federer Faces Knee Surgery, Putting His Future in Doubt
Roger Federer ruled out of French Open as doubts swirl again over
Meniscus
Roger Federer Honoured At On-Court Ceremony In Shanghai
How Will We Remember Roger Federer? - The Atlantic
Roger Federer out for season after second surgery on right knee
Tennis Great Roger Federer Pledges $1 Million To Coronavirus
Roger Federer's tennis future in doubt after shocking speech
Roger Federer - Wikiwand