ACL surgery

So around a month back, i had an accident and tore my acl and meniscus, the doctors have advised a reconstructive surgery because apparently it doesnt heal on its own(keep in mind im only 19). Theyve asked me to get physiotherapy pre surgery and have set a criteria that i must fold my knee atleast 120 degrees before they can operate and would use a screw and a button to stabilize it. Now here comes the twist, i want to join the army but with the implants in my knee i cant, so is there anyone who went through the same surgery or a doctor who can tell me if this is just a money minting unnecessary stunt theyre pulling or are the implants really important? Also anyone whos gone through the surgery, does your knee function as it did before your acl tear? This is really bothering, i dont want to give up on my goals just because some hospital wants to earn a little more.