your doctor's advice contradicts everything i've read/know/been advised of on ACL reconstruction rehabilitation. keeping your leg immobile for that long will freeze your knee forever. however, getting back into sports before the graft has knitted can pull it out.

tore my ACL and partial tear of MCL in a takedown. popped my patellar ligament in BJJ. dislocated my knee 3x after.

i live in HK and had surgery in BKK (at the military hospital). ACL reconstruction from hamstring graft, repair of torn medial meniscus. my surgeon said NOT to use the big plastic ACL brace because now i have an ACL (makes sense). he told me to use the crutches for 6 weeks whether i needed them or not because of the meniscus. i was told to straighten the leg for a few days to prevent the graft from tightening thus keeping my knee at a permanent bend. my doctor said 8 months before returning to sports-related training, and 1 year before competition.

i was able to walk without crutches after 2 weeks, but still used one because my doc told me to. i did range of motion exercises for a month, and at 2 months i began a very aggressive self-imposed rehab. after 3 months, i went back to BJJ, warm up and technique only (with a neoprene + side stays brace). at 4 months i began light sparring. i am now 6 months post op. this past weekend i did 2 x 2hr boxing seminars (with the brace because i am still weaker in that leg and afraid of torquing it).

i am the best-case scenario. three guys in my gym had ACL replacement surgery and all were out for a year before returning. this is the norm. i seriously suggest you do a lot of research on ACL rehab ASAP. feel free to contact me and i'll pass on what info i have. REHAB REHAB REHAB! that's the key!