Skeletal overgrowth with modelling error in neurofibromatosis

Ipsilateral Healthy-segment Response to Leg Length Discrepancy

BACKGROUND

Few studies address frequency or magnitude of healthy lower-extremity segment response to ipsilateral companion segment shortening. We sought to document and quantify this occurrence in a variety of pediatric etiologies.

METHODS

We reviewed the medical record and radiographs of patients undergoing epiphysiodesis to manage leg length discrepancy. Inclusion criteria for this study were leg length discrepancy of a single lower-extremity segment by identifiable cause and adequate scanograms to allow accurate measurement of all 4 lower-extremity segments before any surgical treatment for the discrepancy. We recorded the etiology of shortening, age of onset of disorder, the length of the lower-extremity segments on scanograms, and age at the time of radiographs. We considered ipsilateral healthy-segment difference from the contralateral ≥ 0.5 cm. as clinically significant.

RESULTS

Two hundred nine patients met inclusion criteria (126 boys, 83 girls). The average age was 12.5 years. 16/60 patients with avascular necrosis of the hip demonstrated ipsilateral tibial shortening averaging 1.2 cm whereas 6/60 demonstrated ipsilateral tibial overgrowth averaging 0.6 cm. 11/30 Legg-Perthés patients demonstrated ipsilateral tibial shortening averaging 0.7 cm; none had ipsilateral tibial overgrowth. 10/42 posteromedial bow patients had ipsilateral femoral shortening averaging 0.8 cm, whereas 6/42 had ipsilateral overgrowth averaging 0.8 cm. 13/48 with distal femoral physeal injury demonstrated ipsilateral tibial shortening averaging 1.2 cm, whereas 6/48 demonstrated ipsilateral tibial overgrowth averaging 0.8 cm. 8/29 tibial physeal injuries (proximal or distal) demonstrated ipsilateral femoral shortening averaging 1.1 cm. whereas 7/29 demonstrated ipsilateral femoral overgrowth averaging 0.7 cm.

CONCLUSIONS

Although there are individual exceptions, the ipsilateral healthy segment does not grow appreciably more than the contralateral in patients with avascular necrosis of the hip, Legg-Perthés disease, or physeal trauma. The femur is not a significant component of shortening in patients with posteromedial bow.

LEVEL OF EVIDENCE

Level III, retrospective review.

Congenital pseudarthrosis of the fibula and valgus deformity of the ankle in young children

Treatment of cases of congenital pseudarthrosis of the fibula presenting with severe or progressive valgus deformity in early childhood is challenging. The purpose of the study presented was to analyse the deforming mechanisms to get therapeutic recommendations for this condition. A 2.5-year-old child was treated by resection of pseudarthrosis and distal tibiofibular fusion (Langenskiold operation) with autogenous bone grafting, associated with subtalar arthroereisis: progressive correction of the deformity was achieved. A 21-month-old child was treated with resection of pseudarthrosis, homologous bone grafting and fibular osteosynthesis: after failure, Langenskiold operation with autogenous bone grafting was performed and stabilization of the deformity was achieved. In young children with congenital pseudarthrosis of the fibula and valgus deformity, early surgical treatment is advisable: fibular ostheosynthesis has limited indications; distal tibiofibular fusion remains the treatment of choice, providing correction that may exceed the simple stabilization of deformity expected. Radiographic findings lead the authors to suggest that part of the effectiveness of the procedure is due to abnormal growth patterns.

Familial neurofibromatosis-1 and Gilbert syndrome

BACKGROUND

Neurofibromatosis (NF) is a genetic disorder of the neural sheet, affecting almost all organ systems.

METHOD

A family that consisted of the father and his three children, two males and one female, having NF-1 is evaluated in detail for cosmetic purposes. The routine preoperative laboratory examinations, including complete blood counts, serum biochemistries, urinary analysis, extremity and chest roentgenograms, ultrasounds of the abdomen and the affected regions, and pelvic computed tomographies, revealed characteristics of NF-1 and unexpected hyperbilirubinemia. The patients are evaluated further for the cause of hyperbilirubinemia by the fasting test. Variously localized plexiform neurofibromas of the three children are totally excised.

RESULTS

The father was affected as a result of a mutation, and his three children had inherited the disease. The father, having subcutaneous neurofibromas, differs from the children, as they have elephantiasis neurofibromatosa. The children had various rare clinical presentations besides disfiguring deformities. Two male patients had retroperitoneal neurofibromas, and one had splenomegaly and osseous changes. Gilbert's disease was diagnosed, interestingly, and coincidentally in the three patients with elephantiasis due to NF-1.

DISCUSSION

An interesting diagnosis of NF occurring coincidentally with Gilbert's disease in a family is reported. This clinical study is the first report of Gilbert's disease accompanying familial NF.

Scintigraphic differentiation of congenital soft-tissue extremity enlargement with Tc-99m DTPA

Radionuclide imaging of benign soft-tissue tumors sometimes associated with extremity enlargement (7 patients) and/or osteodysplasia (6 patients) has demonstrated, in a total of 18 patients, several differentiating patterns of accumulation of Technetium-99m diethylene triamine pentaacetic acid (Tc-99m DTPA). Early imaging (within 15 min) as well as later imaging (one-half hour to 3 hours following the intravenous injection of the radiopharmaceutical) has shown that fatty tumors (lipomas, lipoblastomas, fibrofatty tissue) do not concentrate the isotope. Neurofibromas display gradual intensification of their radioactive content, while hemangiomas differ in their scintigraphic pattern depending on their histologic composition. Purely capillary hemangiomas have transient early intense activity while purely cavernous hemangiomas display no early activity but are well visualized on delayed scintigraphic images. Mixed hemangiomas display combined imaging characteristics of both capillary and cavernous types with the predominant pattern dependent upon the predominant histology. Aggressive fibromatosis exhibited an early fleeting display of intense radioactivity.