My sweet spot is also at 20mg/ed. Increased for tests to 25mg/ed. The additional effect is not worth to mention.
To OP: there are many possibilities and some ar non-drugs based

For your special situation, I wouldn't recommend LGD. A 12 weeks run with max 15mg/ed Ostarine is acceptable (my opinion based on own experiences). Had better blood results - and sustainable gains - after 11 weeks with max. 20mg/ed Osta in comparison to 9 weeks 7mg/ed LGD (couple of days at 10mg/ed for tests).
Even 10mg/ed have a strong anabolic/anticatabolic effect, so more doesn't mean better.
Beside you could run GW, which also has an anticatabolic effect. Be sure - if you are running GW - to use at the same time tribulus terrestis, to be on the safer way.
The healing effect is a funny topic in the SARM section. While the decreasing estrogen normally leads to dry joints, there must be something other that causes this "healing" effect. Me personally didn't experience any healing effect. Probably because I have healthy joints (up to now) and never had an accident in my workout history (just once in the squat rack I felt something weard in my left knee, but didn't came back...).
Beside these drugs I can recommend to workout. Yes, you red right. Workout.
Forget the upper body or excercises wirh you arms. I'm talking about the legs.
The legs have the biggest muscle structure in the body and by training them the other muscles in your body will also grow. Stimulating the leg muscules leads to incresed testosterone values (up to 3x times) and increased GH (up to 7x times). Of course only in a short period of time. While testosterone will fall back to the normal value quickly, you still will benefit from higher GH values in your body.
To keep it short: manage to go twice a week for leg excercises without using your arms (leg press 45°, leg biceps excercises, some calves and MOST IMPORTANT: squats, maybe not free but the led ones). One day or week higher volumes and the other with more weights - but still right technique, please - and lower reps.
I guarantee you: combined with max. 15mg/ed Ostarine you will have only a slight decrease in power of upper body excercises. With the described methods you are on the best way to optimize your situation.
All the best with your surgery and fast regeneration.
san