Will I ever get back to 100% after a knee reconstruction?

No. The knee can be damaged from trauma (e.g.Fracture or torn ligament) or arthritis. The prognosis for recovery is related to the severity of the damage and the magnitude of the reconstruction. After minimal surgery like arthroscopy for torn meniscus complete recovery is expected. After knee replacement, 95% jave good pain relief, but only 40% feel like their knee is "normal".
What kind? Do you mean acl reconstruction?If so, you can get pretty close. If you mean knee replacement, no. Replacements give very good function and pain relief but not 100%. They are not for running on. But tennis is okay and golf and swimming and dancing and biking are all good.