[MrHat]

#28753

I’m an author of children’s books published by Holiday House, New York (and elsewhere). I’ve been working for over two years on a new young adult novel that deals with the aftermath of a very serious DUI incident. The story is set in 1981.
The central figure in my story is the young adult girl, although her mother runs a close second. The girl suffers several serious injuries, including damage to her femoral nerve (by compression during a pelvic crush). The result of the nerve damage (as I have it at present) is that she loses the use of her quadriceps to a such a degree that she suffers a permanent loss of knee flexion and will be obliged to wear a knee brace for the rest of her life. At the same time, the ability to flex her hip is left effectively intact (this could be changed, if necessary). My question is whether it is possible for femoral nerve damage to have this effect (i.e. Loss of knee flexion, yet with adequate hip flexion remaining to enable her to thrust the damaged leg forward in a close to normal way). The question might be a bit problematic. A practical answer will do.
The initial symptom of the problem is that after regaining consciousness, the girl discovers that she can raise her damaged leg, but she can’t straighten it out in the normal way.
The medical aspect of my story is in reasonable detail and it is important, but the story focuses on the life-altering impact the DUI has on the girl; and, as well, the impact it has on her family and friends and other people who play a significant role in her life including the doctors and others who treat her.
I’ve searched long and hard on the Internet for an answer to my pivotal question, but so far without success. If I get help from the forum (or from anyone associated with it), I will acknowledge and thank them in my book—if and when it’s published.
It’s my hope that this novel will help deter young drivers and others from driving while under the influence of alcohol and other drugs.

[Donald Corenman, MD, DC]

#28755

You are correct to assume that femoral nerve crush can selectively affect this character’s ability to straighten her knee without causing psoas weakness (the ability to flex her hip). The L3 and L4 portion of the nerve would be affected without the L2 portion injured. You could also have the same affect with a disc herniation or fracture at L3-4 that could compress the L3 or L4 nerves (quadriceps muscle is generally from L3 with some connection to L4 also).

Weakness of the quad muscle would require the protagonist to have a knee brace locked in extension (straight). The gait this individual would display would be called a “vaulting gait” as normally the knee joint is flexed making the leg “shorter” so you don’t have to vault over the leg. When the knee is locked in extension, this lengthens the leg. The individual would have to vault over the long leg creating a significant non-symmetrical gait. The amount of energy needed to walk is significantly increased and the gait would be slower.

There is however some work being performed on a “spring-loaded” knee brace that can bend at the knee, store energy and return it when walking, somewhat like a below the knee amputation with a carbon energy-return foot.

Dr. Corenman

PLEASE REMEMBER, THIS FORUM IS MEANT TO PROVIDE GENERAL INFORMATION ON SPINE ANATOMY, CONDITIONS AND TREATMENTS. TO GET AN ACCURATE DIAGNOSIS, YOU MUST VISIT A QUALIFIED PROFESSIONAL IN PERSON.
 
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.

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