Kinesiology Thursday - Quadriceps AMI following TKA

Arthrogenic muscular inhibition of the quadricep, significant neural inhibition of the quadricep, is a common problem following knee surgeries of any type, but especially total knee replacements. A recent narrative study discussed common factors, joint effusion and edema being two of the main factors. This study is worth a read and it got me thinking about three simple things we can do to help mitigate quadricep AMI in our patients.

“I don’t think I need to be here,” my patient said yesterday. She underwent right TKA in October 2023, the edema in her right leg still obvious. She had achieved normal ROM (130˚ of flexion) and 0˚ extension. She was able to generate a 4 MMT for quadriceps in sitting, but she was unable to stand up out of a chair without using her arms for assistance and her gait pattern. I could talk on and on about the gait deviations she exhibited, using her hip flexors to advance her leg forward. She felt her leg was heavy and was beginning to experience strained feelings in her lower abdominal muscles with walking.

This was six months post-op. Quadriceps AMI doesn’t just go away. With solid intervention, we can help our patients regain normal function. Here is my top three list of interventions for quadriceps AMI.

Get rid of swelling. Retrograde edema massage and kinesiotaping technique (one of the best ways I know to control post-surgical knee swelling). Also advise on compression stockings
Restore normal terminal knee extension. This requires the femur to internally rotate and the tibia to externally rotate. One of the main culprits in preventing this is a trigger point in the medial hamstring. Release it and your patient will be able to get knee hyperextension without feeling a joint jam.
Restore subtalar joint eversion. Mobilize the subtalar joint and release trigger points in the medial gastrocnmeius.

Solely using seated MMT as a measure for quadricep strength without restoring the ability for a solid quad set can set a patient up for months of needless pain and biomechanical dysfunction. Get rid of edema and trigger points to normalize quadricep function.

Because nobody has time to be in pain.

Until next time…