Even after knee surgery, people cannot bend their knees without pain

Limitations in knee flexion are common, although newer surgical techniques and prosthetics have improved this.

Dr. Keith Roach
| For your health

Dear Dr. Roach: My brother, who was extremely active and athletic in his younger years, is now in his early 70s. His decision to have both knees replaced several years ago was not due to general pain, but due to the inability to bend his knees more than 90 degrees. It limited his mobility and affected his quality of life. Afterwards, his surgeon commented that he had never seen knees in such poor condition.

But since that time, my brother still cannot bend his knees more than 90 degrees without excruciating pain. The surgeon’s comments after surgery indicate that new knees were needed, but do you have any insight into the cause of his continued inability to bend them?

— BR

Dear BR: Knee replacement surgery is generally chosen due to osteoarthritis. Usually pain is the main problem, but sometimes it is due to limitations in range of motion. Flexion is the ability to bend your knee, moving your heel toward your buttocks, and extension is the straightening of the knee. These are routinely limited before surgery, but are generally much better afterwards as the damaged part of the knee is literally removed and a prosthesis is fitted.

Limitations in knee flexion are common, although newer surgical techniques and prosthetics have improved this. Various factors can lead to limitations in flexion. Post-operative scars are a possible cause. But considering how bad his knees were before surgery (you never want to hear your doctor say you have the worst case they’ve ever seen), I suspect his quadriceps (the muscles in the front of the thigh that extend the knee) may have lost his flexibility because he couldn’t stretch fully during the years he had arthritis.

The key to improvement is usually gradual exercises to flex the knee – not to the point of excruciating pain, but to the point of stretching the quadriceps. He will need to do this many times a day, and ideally he would work with a physical therapist who has experience with knee replacement patients. Over time, almost everyone will experience an improvement in their ability to bend without pain.

Occasionally the problem is due to scar tissue and the surgeon will perform manipulation of the knee under anesthesia to loosen the scar tissue. Personally, I have never had a patient need to have this done while adhering to physical therapy.

Dear Dr. Roach: What does it indicate if your anti-TPO level is high and your TSH level is normal while you are taking levothyroxine?

— SR

Dear SR: Thyroid peroxidase is an enzyme used to make thyroid hormone. It is necessary for the thyroid gland to work properly. Antibodies against this enzyme are found in autoimmune thyroid diseases, especially Hashimoto’s disease, but they can also be found in Grave’s disease.

The fact that your TSH level is normal with thyroid replacement means that the dose of thyroid hormone is probably sufficient. With these results, the most likely diagnosis is Hashimoto’s thyroiditis with properly treated hypothyroidism.

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