20 weeks ultrasound: short femur

[toro2008]

We just had our 20 week anatomical scan completed today 17 January 2008. During this ultrasound the radiologists has noticed that the rigth femur is substantially shorter then the left one. These results were confirmed by a 3D ultrasound as well.

Exact measurements from the ultrasound report are:
Comments
Left femur: 32mm, Tibia 28mm, Humerus 32mm, Ulna 30mm
Rigth femur: 20mm, Tibia 27mm, Humerus 32mm, Ulna 29mm
Left echogenic intracardiac ventricular focus
Chest/Abdominal circumference ratio = 0.89, normal
Opinion
Short rigth femur, likely due to proximal focal femoral deficiency

All other measurments are normal. Average size is 20.6 weeks
Amnio test done on January 3, 2008 results are not in yet. The reason for amnio was my age 37.

A follow up ultrasound is scheduled for February 4, 2008 to follow on long bone growth.

It came as a shock to me and my husband since we knew nothing about this before and we certainly could not have anticipated this. We spent the enire day in agony reading the internet about this condition. We are seeking out for any reputable answers to the questions we have rigth now.

1. Is there any chance at all the bone would be able to catch up in the next few weeks?  
2. Can this conditon suggest of any other fetal deseas or anomalies in the baby.
3. What are the other possible diagnosis for short femur?
4. Who should we seek for help at this stage?

Thank you in advance.

[AME03]

This definitely sounds like PFFD to me. My husband is 25 and as PFFD. He had a relatively "normal" childhood with his mother giving him the freedom to act like a "real" boy. In terms of birth defects, I feel it is a pretty decent outcome as he has only one physical abnormality and everything else is what society deems normal. He did choose, his mother allowed him to, to have his foot amputated at the age of 10 in order to have his first bending prosthesis. The best guess the doctors gave his mother was that this is something environmental, not genetic. In the early 80s she was exposed to the orkin man spraying in a home where she was the nanny, when she asked them if it could hurt her fetus, they of course told her no because they did not know at that time. He runs, mountain bikes, kayaks, everything. My husband suggests having the foot amputated as soon as the doctor advises and arresting the growth plates around the age of ten. My husband also urges you to treat your child just like any other child, not keeping him from activities that may scare you. My mother-in-law always told me that she would always be terrified when he was climbing trees, etc. but she would allow him to try whatever he wanted and would watch from a distance making sure he was capable. She did not have any ultrasound showing a leg deformation during her pregnancy so I would consider yourself lucky to be able to prepare yourself for this. There have been some new treatments with bone stretching. I wish you all the best and assure you that no matter what, your baby will be special gift and will be made stronger from this.

[budget4]

Please post any other information you find about this disorder or other likely causes of one femur being shorter than the other. My sister had a 30-week ultrasound last week and the Dr. called her with the same news today. I'm looking now to find any other information or diagnoses...

Thanks and best of luck to you both...

[Sumer K Sethi, MD]

Proximal femoral focal deficiency (PFFD) is an uncommon but complex problem.  In general, in individuals with PFFD, the proximal femur is partially absent, and the entire limb is overall shortened. The etiology of PFFD is not known exactly, but certain theories have been proposed and agents implicated.  Injury to the neural crest cells and injuries like anoxia, ischemia, irradiation, bacterial and viral infections and toxins, hormones, mechanical energy, and thermal injury.  Surgical and treatment options are better discussed in pediatric forum or orthopedics, on USG it looks like PFFD only .