TO THE EDITOR:
I was interested in the article "Progressive Genu Valgum Secondary to a Fibrous Tether at the Distal Aspect of the Femur. A Case Report" (80-A: 424-427, March 1998), by Amillo et al., as I have seen a similar patient.
Amillo et al. suggested early curettage of the lesion. Although they speculated that the deformity of the lower limb could eventually correct spontaneously, thus avoiding the need for a corrective osteotomy, they had no personal experience with such an outcome. An excellent result was achieved for my patient without an osteotomy, which supports their idea.
A two-year-old girl was first seen because of a genu valgum deformity of 17 degrees (the valgus angulation on the contralateral side was 7 degrees) (Fig. 1). Radiographs revealed the typical appearance of a fibrous tether on the lateral side of the femoral diaphysis. At the time of the operation, when she was three and a half years old, fibrous tissue was removed with a curet from a small and superficial cyst that extended on a three-centimeter-long band on the lateral part of the cortex (Figs. 2-A and 2-B). No osteotomy was performed. One year later, the deformity had nearly disappeared, and by the time that the patient was nine years old the lower limbs were normal (Fig. 3).
R. Kohler, M.D.: Pediatric Orthopedic Surgery, Hôpital Edouard Herriot, Pavillon T bis, 69437 Lyon CEDEX 03, France
Dr. Amillo, Dr. Mora, and Dr. Léniz reply:
We think that the patient described by Dr. Kohler is similar to ours and to those of Beaty and Barrett1 and Vallcanera et al.2. Although Dr. Kohler does not mention the histological findings related to the cyst or band, we think that the age at appearance, the radiographic findings, and the unilateral progression of the deformity make the case of his patient very similar to those of the other six. The fact that excision of the tether alone corrected the deformity and prevented progression confirms our theory that a single excision without osteotomy is appropriate if the valgus or varus deformity is less than 20 degrees. It also confirms our statement that excision of the band is necessary to prevent additional deformity.
We think that the key to adequate treatment is close follow-up of the deformity and early operative treatment if there is progression.
Santiago Amillo, M.D.; Gonzalo Mora, M.D.; Patricio Léniz, M.D.: Department of Orthopaedic Surgery and Traumatology, University Clinic of Navarra, Avenue Pio XII 36, 31008 Pamplona, Spain