Unilateral femoral deformity due to a focal fibrous tether

Correction of Angular Deformities Due to Focal Fibrocartilaginous Dysplasia Using Guided Growth: A Preliminary Report

BACKGROUND

Focal fibrocartilaginous dysplasia (FFCD) is a rare benign disorder that may result in tethering of the physis. These most commonly occur around the knee and may result in angular deformities of the involved extremity. To date treatment has ranged from observation, to curettage, to osteotomy. Our goal with this study is to evaluate the efficacy of guided growth in treating patients with angular deformity due to FFCD.

METHODS

This is a retrospective review, we included 3 patients with angular deformities due to FFCD who had undergone 8 plate placement. We reviewed their preoperative and postoperative radiographs, assessed their sagittal and coronal balance and number of procedures.

RESULTS

Three patients with FFCD of the femur with an average of 14 months underwent guided growth to correct their angular deformity. Once appropriate correction was achieved the hardware was removed. At final follow-up none of the patients required further surgical intervention for their angular deformity nor had they shown any evidence of recurrence.

CONCLUSIONS

FFCD is a rare benign disorder, they most commonly affects the proximal tibia and distal femur and can result in significant angular deformities. Our review of the literature found all of the cases involving the femur progressed to the point where they needed surgical intervention. This ranged from curettage to osteotomy. In this case series we present 3 cases of FFCD of the distal femur that were treated minimally invasively with guided growth.

LEVEL OF EVIDENCE

Level 4.

A patient with focal fibrocartilaginous dysplasia in the distal femur and review of the literature

Focal fibrocartilaginous dysplasia (FFCD) is a rare and benign bone lesion that induces bowing deformity of the long bones in young children. Excessive production of fibrocartilage by abnormal differentiation in the metaphysis or by trauma during delivery or after birth is thought to cause growth disturbance. Radiologically, the lesion is characterized by a lucent defect with marginal sclerosis in the medial metaphysis of the long bone. However, there have been few reports about the initial radiological changes of FFCD before bowing started. We report a patient with FFCD in the left distal femur in whom the radiological changes were serially observed during the course of the disorder. A 2-week-old boy first visited our hospital because of left thigh pain. Plain radiographs did not show any abnormal findings at that time. At 10 weeks, a well-defined lucent defect with bony fragment inside was observed in the distal femoral medial cortex. At 1 year, this bony fragment gradually vanished but varus deformity progressed and reached approximately 40 degrees at the age of 2. After removal of the lesion, osteotomy and immobilization was performed with Ilizarov external fixator comprising rings, rods and wires. Complete bone union was achieved 3 months after operation. It is noteworthy that we could observe the initial radiological changes of FFCD before varus deformity occurred. As far as we know, there have been no descriptions of the bony fragment inside a lucent defect of the lesion. Radiological features may vary in the early phase of FFCD.

Unilateral limb deformity due to fibrous tethers: a report of three cases

Fibrous tethers are a rare cause of unilateral limb deformity. A review of the literature revealed 9 cases previously described, all located in the distal femur. We report 3 additional cases of fibrous tethers, 2 of which were located in anatomical areas not previously described. The fibrous tethers were excised in all cases, and an osteotomy was performed in 2 of the cases. The clinical, radiological, and histopathologic findings are discussed for each case.