A Patient with Focal Fibrocartilaginous Dysplasia in the Distal Femur and Review of the Literature

Abstract

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 immobilzation 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.focal fibrocartilaginous dysplasia; femur; osteotomy; Ilizarov external fixator.Tohoku

Focal fibrocartilaginous dysplasia in the ulna with the radial head dislocation: a case report and literature review

“…Ando et al [7] reported 89 cases of FFCD from 1985 to 2007, and 54 (61%) of these were located in the proximal medial tibia.…”

“…Although there are some opinions on the origin of the pathology, the common understanding that has emerged recently is that FFCD is characterized by abnormal development of fibrocartilage at the site of tendon insertion, which prevents natural sliding of the periosteum of the metaphysis and diaphysis during growth [7,12].…”

“…Since Bell et al [1] showed three cases of tibia vara as FFCD for the first time in 1985, more than 50 cases in the proximal tibia and more than 15 cases in the distal femur have been reported [1][2][3][4][5][6][7][8]. Although FFCD had been considered a specific disorder of the knee (proximal tibia, or distal femur), cases of FFCD involved in the upper extremity were reported by Lincoln and Birch [9] in 1997, followed by 21 reported cases at present [8][9][10][11][12][13][14].…”

Focal fibrocartilaginous dysplasia (FFCD) in the proximal femur causing coxa vara: A unique case report and review of the literature

“…16,23,24 It has also been reported at several other sites. This includes the distal femur (18 cases), [25][26][27][28][29][30][31] ulna (16 cases), 3,[32][33][34][35][36] humerus (four cases), 32,37 radius (two cases) 33 and phalanx (two cases), 33 but never in the proximal femur.…”

Excision of fibrous band and application of tension band plating in focal fibrocartilaginous dysplasia: A case report and literature review

“…The tethering effect of the fibrous band causes a hemiepiphysiodesis effect and results in angular deformities as well as limb-length discrepancies of long bones ( 4 , 5 ). Patients are mostly diagnosed with varus or valgus malalignment of the lower extremities at the age of 12–24 months ( 6 ).…”