My 81 year old Mom had a knee done about 4 years ago. She walked to the car with a walker (wheelchair out the door of course) ditched the walker the next day. PT 3 times a week for a month, twice a week for a month which she called 'inconvenient.' She doesn't walk 3 miles every day like she used to so Dad walks with her to Walmart/Burger King/whatever place they want to go, and then Dad goes home for the car. When my brother and I are there one of us gets the car so Dad can stay with Mom. Sometimes, Mom walks home with Dad, depends on how she feels that due to other health issues, not her knee.
Dad starts his Day (well, after Mom brings him breakfast in bed) watching the morning stock reports and Mom reads her Bible. After an hour or so, Dad hits the treadmill for 30 to 45 minutes. Blood pressure meds don't work for him, the treadmill does. And several walks a day are on his routine list, not bad for 80.
Getting older and dealing with the usual maladies comes with the territory. Mom and Dad grew up down the street from each other, having known each other since they were 5. Farm kids, raised by farm kids, Mom's people having come from Texas, Dad's from Oklahoma, you know dust bowl refugees who ended up in Central California. All of my Grandparents lived into their 90s, except Mom's Dad, help got injured on the farm which resulted in a blood infection. I wished I could have known him better.
The point of my little story here is having to wait another year for your surgery seems like a choice made with good intention and reason. You know you don't want to miss your summer there and will put up with the 'inconvenience' of a bum knee. Mom felt better the day after she had her knee done and wanted to do her own PT at home. Well, doctors and physical therapists don't like missing out on a 'billable hour,' just like attorneys. Enjoy your summer, I hope the shot helps, may God provide the strength and assurance that all will go well.