Thank you for the query.
is rather not caused by knee fall. The only possible way it could cause vertigo is a blood clot which has migrated from leg veins and went to the lungs causing shortness of breath
It is rather vertigo which has caused your fall and this should be explained. It is advisable for you to have heart diagnostics (ECG, stress test
, 24 hours Holters ECG), cervical arteries ultrasound
, internal ear tests, and neurological examination.
Hope this will help.