on the joint for 3 to 4 weeks to allow sufficient time for the structures to heal. Following immobilization, the patient can begin exercises to improve range of motion and begin bearing weight on crutches only. The crutches can be discontinued when the patient can walk without limping. Quadriceps strengthening exercises are allowed, but no isolated hamstring exercises should be attempted for 6 – 10 weeks following the injury. If after 10 weeks, pain or instability continue, the patient should be reevaluated for surgical treatment. Operative treatment This portion of the knee is felt to contain the most complex anatomy and to be the rarest type of knee injury. For this reason, consideration should be given to referral to a complex knee specialist for treatment. Surgical treatment of posterolateral corner injuries depend on whether the injury is of an acute or chronic nature and whether it is isolated to the posterolateral corner or combined with another ligamentous injury. Operative treatment is aimed at an anatomical repair or reconstruction rather than a non-anatomic reconstruction of the torn structures when possible, because this provides the highest odds of a successful return to function. The optimal time for treatment of acute injuries is within the first 3 weeks to avoid complications caused by scar tissue and the body's repair mechanisms. Chronic PLC injuries are less likely to be amenable to repair due to complications from scar tissue and limb malalignment; these injuries will likely necessitate reconstruction. Knees in varus alignment and which have chronic injuries (evaluated by long leg standing radiographs) will require a staged procedure that starts with an opening wedge osteotomy. This procedure lessens the constraint on the knee and prevents the reconstruction grafts from stretching out. If the patient still has instability, the PLC reconstruction will take place approximately 6 months later. MRI scans will be helpful in determining whether torn structures are amenable to repair or will require reconstruction with allografts. The structures considered for potential reconstruction are the fibular collateral ligament, popliteus tendon, and popliteofibular ligament. The FCL and/or popliteus tendon are only considered for acute repair when they are avulsed off bone and can be reattached anatomically with the knee in extension. The PFL can be repaired when it is torn directly off of the fibular head and the popliteus is still intact. Reconstruction is preferred when the ligaments/tendons have mid-substance tears or other tears not amenable