I am 43. am suddenly experiencing stiffening of knee joint and pain on backside of knee after sports. what can be the causes and treatment?

Arthritis v meniscus: A suddenly stiff knee joint with pain on the back side is consistent with an injury within the medial knee compartment of the knee. Possibilities include an mcl sprain, meniscal tear, or cartilage injury. The posterior pain is usually non-specific, but results from an accumulation of fluid (effusion) within the joint. Initial treatments: rest, ice, ace wrap compression. Pcp exam if no improvement.

1 of 2 Arthritis?: Generally pain in the back of the knee does not point to a specific structural injury. Oftentimes if the knee is "angry" it will produce excess fluid which tends to settle in the back of the knee and irritates the knee causing pain. Most likely cause of your knee being "angry" is early arthritis (cartilage loss/wear). Other causes include meniscus tears, tendinitis and inflammation.

2 of 2 Treat: Initial treatment includes modifying activity level, ice, nsaid's, therapy and use of knee sleeves. If this fails then your doctor may discuss injections and even surgery depending on what your work-up such as x-rays and MRI reveal.

Swelling: Pain and stiffness after sports participation often is the result of swelling. Swelling can result for several different reasons. Injuries such as meniscal tears, repetetive use, condromalacia or even early arthritic changes. If this persists then an orthopaedic evaluation would be indicated.