Ive been getting knee pain for a while in the same leg that i had a tibial nail in some 7 years ago. My quad on that leg has never really come fully back to the size of the other leg. I have an office job, so I m relatively inactive during the day usually, but have had the last 2 weeks off as holiday and have been more active moving some furniture, fixing things around the house, some home improvement and a bit of gardening. This morning I woke IP with a round, painless bruise on my kneecap, near the top inner edge. My knee does grind a little at full extension, but that happens quite a lot anyway. Over the past week, the quad muscle on the affected side has grown and become more responsible, but is still smaller than the other side. The knee is reasonably painful during stress and occasionally hits a big bit of pain when extending under load.
Hello, You had mentioned the previous history of trauma at knee and nailing had been done before 7 yeras, so might be that may cause compression and irritation to joint tissue. To rule out we must go for X-ray. Another cause may be due to continuously repeated heavy work, your qua Chat Doctor.  You should walk regularly do cycling swimming running jogging, if the pain is subsiding it means your thigh muscles were weak, or else you need to take an x-ray for the knee joint. Hope I have answered your query. Let me know if I can assist you further. Take care Hem ang S Jane, Physical Therapist or Physiotherapist