Ulnar focal cortical indentation: a previously unrecognised form of ulnar dysplasia

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.

Ulnar focal cortical indentation: a progressive, deforming variant of focal fibrocartilaginous dysplasia

BACKGROUND

Focal fibrocartilaginous dysplasia is a rare growth disturbance of bone resulting in deformity. In the ulna, focal fibrocartilaginous dysplasia is particularly rare, and the characteristic fibroligamentous tether can result in progressive deformity with progressive dislocation of the radial head. The fibroligamentous tether is similar in appearance and function to the Vickers ligament seen in Madelung deformity. The imaging features of ulnar focal fibrocartilaginous dysplasia include a unilateral angular deformity in the ulna with a radiolucent cortical defect and surrounding sclerosis, with secondary radial bowing or radial head dislocation. Focal fibrocartilaginous dysplasia of the ulna has been described using the term ulnar focal cortical indentation.

OBJECTIVE

To review the clinical and radiologic features of four cases of ulnar focal cortical indentation occurring in pediatric patients.

MATERIALS AND METHODS

We retrospectively reviewed picture archiving and communication system and electronic medical record imaging findings with surgical correlation of ulnar focal cortical indentation at two large specialty pediatric hospitals.

RESULTS

Ulnar focal cortical indentation lesions typically arise in the ulnar metaphysis and result in angular forearm deformities with progressive radial deformity including radial head dislocation. Early surgical intervention prevents progression of the deformity and retains range of motion.

CONCLUSION

Ulnar focal cortical indentation, although rare, is likely a progressive form of focal fibrocartilaginous dysplasia resulting in significant deformity and disability. Early recognition of the characteristic imaging features is important for early surgical intervention to preserve range of motion and prevent radial head dislocation.

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.

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

Focal fibrocartilaginous dysplasia (FFCD) is a rare benign bone lesion, which mainly occurs in the proximal tibia. In the upper extremity, only 21 cases have been reported so far and 14 of these involved the ulna. We present an additional case of FFCD in the distal ulna that showed progressive bowing of the right forearm and the radial head dislocation. Resection of the abnormal tissue, osteotomy of the radius and ulna, and gradual lengthening of the ulna were performed. On the basis of the previously published data of 14 cases and our data, we have summarized the etiology, clinical features, natural history, and treatment of FFCD in the ulna.

Focal fibrocartilaginous dysplasia in the ulna: report on 3 cases

Focal fibrocartilaginous dysplasia is an uncommon, benign bone lesion that causes deformity in young children. It is most commonly encountered in the proximal tibia, with few cases documented in the upper extremity. We report 3 cases affecting the ulna. In each case, the fibrous tissue appeared to anchor itself in the ulnar diaphysis, behaving as a tether that retards growth. All 3 patients had excision of the fibrous tissue. There was concern for radial head subluxation before surgical intervention, but all patients maintained a congruent radiocapitellar articulation. The visible deformity improved in all 3 patients, although the limbs remained shorter than the contralateral side. In our limited series, we believe that early excision of the fibrous tissue tether can prevent radiocapitellar joint dislocation in patients with focal fibrocartilaginous dysplasia of the ulna.

Focal fibrocartilaginous dysplasia ("fibrous periosteal inclusion"): an additional series of eleven cases and literature review

Focal fibrocartilaginous dysplasia (FFCD) is a benign condition first described in 1985 as a cause of tibia vara. We are reporting on 11 cases. The lesions involved proximal tibia (9 cases), distal femur (1 case), and distal ulna (1 case). We believe that this entity represents a bony anchor preventing natural sliding of the periosteum during growth (an "epiphysiodesis-like" effect). For the tibia, we believe this is the pes anserinus. We are suggesting that this entity be called a "fibrous periostal inclusion." Treatment indications result from this concept: (1) for tibial lesions with a metaphyseal-diaphyseal angle less than 20 degrees observation for 6 to 12 months; (2) if the deformity improves, the tether likely broke spontaneously, and no treatment is required; and (3) curettage early if the deformity worsens. This will be followed by rapid correction into physiological valgus (tibia) and prevent the need for osteotomy. Early curettage for other less common locations is recommended.