After this physiotherapy help must

Go for strong and vigorous physiotherapy exercise treatment.you will be ok after that. it will provide you the right strength, balance and co-ordination.

Required quadriceps strength training exercises and gait training.

Quadriceps Exercises- Lie straight, make a towel role and put it under the knee, press the keen against the role, hold it for 20 secs. Repeat 20 times twice a day. This will help relieve some pain. Core Strengthening Exercise- Straight Leg Raised With Toes Turned Outward, repeat 10 times, twice a day.

U must go for muscular strengthening and focus on strengthening hamstring / quadriceps / tibialis anterior / tibialis posterior / IT band / piriformis / vmo / glutes / and calf muscle too..u will be fine in a month or so but dnt stop exs after that...exs is a must for u...get well soon

After surgery you need to do excersices. As you say after surgery your thigh is weak and thin means your thigh muscle need to made strong by excersices. Consult orthopaedic surgeon who operated you show him .with his  advised meet physiotherapist and start doing excersices.

Hello, You need to go for good leg strengthening exs Go for close chain and open chain exs You can go for gym strengthening also but under supervision of a good trainer

Assuming a menisectomy was done . As your said the thigh is thin. It just means there is a lack of exercise. If you do good exercise then the thigh will come almost of the same size as the other side. The difficulty in walking is also due to same. Please go to a physiotherapist to do good quadriceps strengthening exercise. Once the muscle mass regains you will not have much problem with your knee

What kind of meniscus surgery has been done??