Medial Knee swelling with posterior knee pain

my mum (52yrs history of plantar fascitis) is suffering with medial knee swelling and posterior knee pain. finds walking upstairs difficult and lateral rotation. pain described as a dull ache, not constant. the knee problem is on the same limb as the plantar fascitis. any ideas if the problems could be linked? or the knee problem could be related to orthotics?

Your mother most likely has a problem with her medial meniscus, (ie a tear), possibly with a secondary cyst, which may account for the swelling you describe. She obviously has had some previous biomechanical problems in her lower limb which led to the plantar fasciitis-in the same way she may have been causing excessive rotation through her knee in day -to day activites. If the tear is peripheral, it will heal with physiotherapy;if is deeper she may require arthroscopic surgery. Good luck.