PKR My Drama Queen Patellofemoral Knee

[EalingGran]

Patellar Instability Following Total Knee Arthroplasty: A Review of Etiology, Diagnosis, and Management Strategies - PMC https://share.google/2gwYqAH5Tt1rK219S
I thought this might be relevant- although it is after TKR not PKR

 

[Jockette]

@EalingGran Thank you for that article. It confirms all the information I learned last week in my research. It explains why someone has a tracking problem, and mentions implant misalignment. I think the rotational CT scan will show that this is my problem. Every one of my symptoms point to this. A misalignment can also damage the infraptellar branch of the saphenous nerve, which explains the “pole shoved into the side of my knee” hypersensitivity I feel the second I put pants on.

As soon as I mentioned that my surgeon did an intraoperative lateral release, when I didn’t have any previous history of a tracking problem, it pretty much confirmed an implant misalignment.

Then there’s the issue of my not being able to downstairs foot over foot. My research said:

“the inability to walk downstairs foot-over-foot and your hip pushing upward to compensate—is the definitive, textbook sign of an overstuffed or internally rotated patellofemoral joint.

Walking downstairs places the absolute highest mechanical stress on the patellofemoral joint, requiring the kneecap to handle forces equal to 3 to 4 times your body weight.

Why Going Downstairs Causes This Specific Failure

When you step down, your knee must bend deeply while bearing all your weight. If your implant is misaligned or overstuffed, two things happen that physically block this movement:

• The "Jamming" Effect: As the knee bends under weight, the misaligned or too-thick kneecap button jams hard against the side of the metal groove. Because the track is blocked, the knee physically cannot bend any further smoothly.
• The Hip Hike Compensation: To avoid falling forward when the knee jams, your brain instantly forces your body to compensate. It hitches your hip upward on that side to "lengthen" your leg, allowing you to swing your foot down to the next step without having to deeply bend the malfunctioning knee.

The "awful" feeling you get afterward is acute inflammation from the kneecap forcibly grinding against the metal ridge of the implant.”

If my implant is indeed misaligned, my poor knee never had a chance.

 

[sistersinhim]

Very Interesting about that down-stepping. I don't recommend this to anyone, because I have NO kneecaps, but my OS years ago told me to hold on tightly and go down the steps backwards. None of you should try that unless your doctor says to. It just kept me safer.

 

[EalingGran]

Neuroma of the Infrapatellar branch of the saphenous nerve following Total knee Arthroplasty: a case report - PMC https://share.google/00yS8CZh7NMMD66Vp
Another possibility for the neuropathic type pain you describe when put on trousers is a neuroma of the saphenous nerve.
Damage to the infrapatellar branch is almost universal in PKR/ TKR surgery but most of us just have a numb patch which gradually improves. The nasty neuropathic pain can be caused by the surgical damage leading to a rare neuroma.

 

[EalingGran]

The damage to the infrapatellar branch of the saphenous nerve and its relationship persistent pain is interesting. I really don't notice my numb patch on a day to day level now. However, I tried the Tinel test mentioned in the case report above. If I tap with my fingernails on the area of the nerve I can still get a slightly odd tingling/ pricking sensation which is different to the normal skin area nearby. This is almost 4 years after my surgery.
Thankfully it is only ever really unpleasant for me if I accidentally knock that part of my knee. However, it shows that nerve damage can persist in various forms for many years.

 

[Jockette]

@EalingGran I had that normal numb area for a while, like most people, but it’s hardly noticeable now. This other nerve issue is extreme and always has been, since the surgery.