Help! Legs give up on a keto diet

Hello!  I'm on a keto diet for over one year as recommended by a doctor.  Two weeks ago my knees started to hurt, and for the last 5 days I have not been able to stand up (acute knee pain).  Analyzes for electrolytes are normal, cholesterol is much higher than 10.5.  The urine contains 1.5 mmol of ketones.  The kidneys are normal.  MRI of the knee showed rupture of meniscus ligaments and fluid.  Could this be an adverse reaction to the keto diet?  And how do I get out of ketosis gently now?