|Isolated injuries to the collateral ligaments, even third-degree injuries, generally heal well with non-operative treatment. Third-degree collateral ligament sprains associated with other ligament or meniscus damage often require surgery, but generally will heal well. Recovery can be expected when first and second-degree sprains of ACL and PCL are treated with physical therapy and activity alteration. Third-degree sprains of ACL that are surgically repaired, with either primary repair or reconstruction with augmentation, require an extensive rehabilitation after surgery, but recovery can be expected. Surgery to treat third-degree injuries to PCL is rarely performed on middle-aged or older adults unless there is gross instability or associated injuries, especially of the meniscus. Individuals undergoing this surgery require an extensive rehabilitation afterwards, but recovery can be expected.|
Full recovery from strains can be expected after physical therapy for first and second-degree injuries. Third-degree strains involving tendon rupture require surgery (tenoplasty, tenodesis, or a reconstruction with augmentation). Third-degree strains and sprains will require several months for full recovery. Return to limited activity may be expected early in treatment, with an interruption for surgery and eventual return to full activity. Knee braces are often used for all levels of sprains and strains, sometimes only in the early stages of recovery, and often for several months after surgery. Protective braces may be required after recovery to prevent re-injury.
Source: Medical Disability Advisor