Spontaneous resolution of angular deformity of the distal femur in focal fibrocartilaginous dysplasia: a case report

Magnetic resonance imaging of focal fibrocartilaginous dysplasia - findings derived from a three-dimensional gradient echo sequence

BACKGROUND

Focal fibrocartilaginous dysplasia is a rare benign bone lesion of young children that causes deformities in the extremities. However, the pathogenesis and treatments have not been defined and the MR manifestations have been less well described.

OBJECTIVE

To describe the MR manifestations of focal fibrocartilaginous dysplasia, especially on the T1-W three-dimensional (3-D) volumetric interpolated breath-hold examination (VIBE) sequence.

MATERIALS AND METHODS

In this retrospective study, the authors reviewed the MR and radiographic images, pathology and medical records of 21 cases of focal fibrocartilaginous dysplasia. All cases were evaluated by spin-echo MRI sequence. Among them, 17 cases were evaluated by T1-W 3-D VIBE sequence.

RESULTS

The cohort consisted of 13 boys and 8 girls ages 4-75 months. In 14 cases, focal fibrocartilaginous dysplasia was located in the tibia, 3 in the femur and 4 in the ulna. MRI 3-D VIBE sequence findings showed all cases had hypointense fiber band structures in the bone defect areas. The fibrous bands in the lower extremities ended in the epiphysis or epiphyseal plate, and in the upper extremities the epiphysis or carpal bone. Ten cases had hyperintensities that might represent cartilage composition. Four cases had cartilage signals that were continuous with the epiphyseal cartilage. MR spin-echo sequence findings showed that bone marrow edema of the adjacent joint was observed in eight cases, enlargement of the epiphyseal plate in three cases and medial meniscus injury in five cases.

CONCLUSION

The 3-D VIBE sequence reveals useful details in focal fibrocartilaginous dysplasia.

Focal fibrocartilaginous dysplasia of the distal femur

Focal fibrocartilaginous dysplasia (FFCD) of the distal femur is a rare disorder that results in a varus or valgus of knee. Due to the small number of cases and unconfirmed natural history of the disease, treatment methods remain variable. This study aimed to determine a strategy to successfully manage distal femoral FFCD. Nine case of femoral FFCD treated in our department between 2008 and 2018, together with 22 cases from literature, were retrospectively reviewed. Tibiofemoral anatomical axis angle (TFA) was used to evaluate and follow the deformities. Treatment methods and outcome were analyzed. Five methods were used to manage the disease: osteotomy with tether release in 14 cases with mean TFA of 29°; simple tether release in eight cases with mean TFA of 31°; guide growth without tether release in 3 case with mean TFA of 27°; guide growth with tether release in 3 case with mean TFA of 27°; and observation in three cases with mean TFA of 23°.Deformity was resolved in all 31 patients. The analysis of the 31 cases in the literature and our experience suggests that femoral FFCD can be successfully managed by simple tether release and curettage. Osteotomy can be avoided. In case of mild deformity (TFA < 25°), it is reasonable to follow-up till 2-3 years of age; if no progress occurs, spontaneous resolution can be expected.

Spontaneous resolution of focal fibrocartilaginous dysplasia of femur on long-term follow-up: case report and review of literature

Focal fibrocartilaginous dysplasia (FFCD) is a rare developmental disorder frequently leading to angular deformities in young children. It most commonly affects the proximal tibia followed by distal femur. There are totally 22 reported cases of FFCD of femur. We report a case of FFCD of distal femur as a cause of varus deformity that was managed nonoperatively. The deformity resolved spontaneously over a period of 8 years. This is the second reported case of spontaneous resolution of angular deformity secondary to FFCD of distal femur. We strongly recommend to observe the behavior of deformity over a period of 24 months before any surgical intervention is planned.

Outcomes in Early Versus Late Presentation of Focal Fibrocartilaginous Dysplasia Affecting the Upper Extremity: A Review of 4 Cases

BACKGROUND

Focal fibrocartilaginous dysplasia (FFCD) is a rare disorder of the upper and lower extremities. In the distal ulna, a ligamentous tether emerging from the metaphysis crosses the physis and restricts growth, leading to deformity. Lesion excision before radiocapitellar subluxation has been shown to restore growth and allow remodeling. We review the outcomes of 4 patients with FFCD of the distal ulna after the occurrence of radiocapitellar incongruity.

METHODS

This retrospective review examined 4 patients diagnosed with FFCD of the distal ulna from 2007 to 2015. Diagnosis was based on radiographic parameters and pathology when available. The radiographic and functional outcomes are reported.

RESULTS

Three males and 1 female patient presented at an average of 37.5 months (range, 22 to 48 mo) with ulnar FFCD and radiocapitellar joint incongruity. The first patient had progressive radiocapitellar dislocation, poor motion, pain, and deformity. The second patient presented for a third opinion after previous surgery secondary to deformity progression and radial head dislocation. These patients required salvage procedures with creation of a 1-bone forearm. Patient 3 had frank dislocation of the radiocapitellar joint, yet maintained functional motion. This family elected for continued observation. Patient 4 had a 50% subluxation of the radiocapitellar joint and underwent tether excision and ulnar lengthening with an external fixator. Both joint congruity and deformity improved with functional forearm and elbow motion.

CONCLUSIONS

Delayed treatment of ulnar FFCD may require salvage procedures to maximize function and provide pain relief.

Fibrous tether of the distal femur produced unilateral genu valgus with subsequent patellar dislocation: case report and review of the literature

Fibrous tether at the distal femur is a rare condition that causes angular deformity of the lower extremity; only 18 cases have been reported previously. We report the case of a 2-year-old boy presenting with unilateral genu valgus. The patient had a subsequent lateral patellar dislocation, 1 year after surgical correction. A second surgery was performed to correct this patellar dislocation. Intraoperative finding indicated contracted lateral patellar retinaculum. To the best of our knowledge, this is the first report of such a finding. The natural history is still not understood. At the 6-month-follow-up visit, the patient still has good results without recurrent patellar dislocation or angular deformity. We also review the literature in terms of proper treatment and results of treatment.

Two unusual presentations of focal fibrocartilaginous dysplasia

Focal fibrocartilaginous dysplasia (FFCD) is an uncommon, yet well documented, cause of long-bone angular deformities in children. We report two unusual cases of FFCD involving the tibia: one within the proximal tibia inducing genu valgum and one apparent FFCD lesion of the distal tibia that generated a varus deformity of the distal tibia. To our knowledge, this is the first reported case of FFCD in the distal tibia. Each lesion led to an angular deformity that required surgical management.