Both knees are hurting. burning sensation. achy when bending. possibilities??

Patella-femoral synd: 25 yo female c/o aching knees might have genu varus or genu valgus; causing abnormal patella-leg bones alignments. Potentiating causal factor might be underlying Joint Hypermobility Syndrome (JHS). Study the Brighton Criteria. Many Rheumatologists discount JHS so avoid them. An Osteopath can discern. Wise podiatrist might be helpful. Non-weight bearing exercise (swimming) helpful. Avoid surgeons.