When A Child Presents With Internal Tibial Torsion And Femoral Varus

This author offers insights on the surgical treatment of a 4-year-old boy with femoral varus and internal tibial torsion.

A 4-year-old boy from Lethem, Guyana came to the attention of the Shuzz Fund organization (a non-profit organization that helps provide medical care, medical missionary work and education) as a possible candidate for surgical reconstruction. On a medical mission through the Shuzz Fund, a local doctor knew of the boy, who had a severe in-toe gait. We went to his village home and performed a roadside examination. Based on the patient’s clinical range of motion and gait observance, we concluded that the child was a good contender for further evaluation and intervention.

Through a passport and a United States visa, the child and his mother came to the United States. At this time, we performed a complete workup. We took X-rays consisting of full leg AP and lateral views from the hip to the toes. Evaluation for spine malalignment was negative. Differential diagnoses included Blount’s disease, rickets, osteogenesis imperfecta or internal tibial torsion. One can best diagnose Blount’s disease by X-ray evaluation of the proximal tibial metaphyseal-diaphyseal angle. Greater than 11 degrees is abnormal and there is often a beak-like protuberance of the metaphysis. In this case, we ruled out Blount’s disease.

On X-rays, it was apparent that there was an increase in the varum of the femur of 35 degrees on the right and 40 degrees on the left. The hip, knee, tibial, ankle and foot segments were within normal limits on X-ray but abnormal on clinical examination. There was no metatarsus adductus. The concern at this juncture was rickets.

The child subsequently saw a pediatrician, who obtained a complete blood panel. The pediatrician ruled out rickets as the patient’s low vitamin D levels were due to malnutrition but they were not at insufficient levels for a disease state. Aside from minor deficiencies, the boy was a healthy 4-year-old.

Deciding On A Treatment Course

After meeting with pediatric orthopedic specialists, we decided that the child had two main components to his condition: femoral varus and internal tibial torsion.

After much consideration, we decided that the femoral varus would likely correct over time. The mother confirmed that it had improved already since birth but she was concerned as he was still severely in-toed. If the femurs do not resolve by 7 to 10 years of age, femoral derotation osteotomies would be a consideration. 

On the other hand, the internal tibial torsion component would not resolve over time. We decided to address the tibial torsion but one must also consider the femur. If the femur resolves, then some of his in-toe problem would correct as well. We planned a slight undercorrection.

A Step-By-Step Guide To The Surgery

We placed the patient in a supine position on the OR table and applied bilateral tourniquets, placing them at a setting of 250 mm Hg.

We utilized fluoroscopic imaging. I made a skin mark 1 inch proximal to the tibial physis. I proceeded to drive ne Steinmann pin from the medial malleolar cartilaginous segment and positioned it distal to the planned osteotomy site. I drove a second Steinmann pin from the tubercle of Chaput on the tibia and placed this distal to the planned osteotomy site as well.

The planned incision was slightly oblique in a proximal lateral to distal medial fashion and was 2 inches long. I carefully took this down through the skin and subcutaneous tissue. Then I incised the periosteum and reflected it medially and laterally. I used Hohmann retractors to encircle the entire tibia and protect the posterior structures.

Using fluoroscopy to verify the position of the osteotomy, I drew a linear line in the tibia with a surgical pen and used an oscillating saw to make a straight transverse osteotomy in the tibia. Once the cut was 90 percent through, I finished the cut with an osteotome. This would prevent any posterior fragments or greenstick fracture. Other techniques that surgeons have described have included a drill hole method or use of a Gigli saw.

After completing the osteotomy, I externally rotated the tibial segment, allowing a correction of 20 degrees. I accessed this by the surgical marker placement. After confirming the position, I advanced the Steinmann pins proximally, crossing the osteotomy site. Crossing the medial and lateral tibial cortices is recommended so the pin does not piston postoperatively. I closed the incisions and the oblique incision was now a linear closure.

In Conclusion

The patient wore above-knee casts for four weeks followed by below-knee walking casts for an additional three weeks. The in-toe portion of his gait was greatly improved but not completely resolved. The child and his mother are still in the U.S. while the child heals from the procedure and there is further determination on addressing the femurs as his opportunities in the U.S. are limited.

Dr. Schoenhaus is a Fellow of the American College of Foot and Ankle Surgeons, and is board-certified in foot surgery and reconstructive rearfoot and ankle surgery by the American Board of Podiatric Surgery. She is in private practice in Boca Raton, Fla.