Pathological Fracture of the Tibia in a Monostotic Anterior Cortical Fibrous Dysplasia: Hybrid Fixation with UnicorticalOsteoperiosteal Non-Vascularized Fibula Graft - A Case Report

Introduction

Fibrous Dysplasia is a relatively rare Musculoskeletal disorders in which there is a defect in remodelling of immature bone to mature lamellar bone. Fibrous Dysplasia was first described by Von Recklinghausen in 1891, but it was Lichtenstein who labelled it polyostotic Fibrous Dysplasia in 1938. Union of Pathological Fractures in a bone affected by Fibrous Dysplasia poses a difficult set of Challenges for treating Physicians.

Case Report

We Report a 24 year-old female patient with a Pathological Fracture of the Tibia in a Monostotic Anterior Cortical Fibrous Dysplasia Hybrid Fixation with a UnicorticalOsteoperisoteal Non Vascularized Fibula Graft with a follow up until the union of fracture site on computed tomography scan and complete integration of unicorticalosteoperiosteal fibular graft .

Conclusion

We provide additional and independent evidence that removal of the diseased cortex which were parts of the proximal and distal fragment and reconstruction of the defect in the cortex with a press- fitunicortical Non vascularized osteoperiosteal fibular strut graft with a hybrid fixation is a good treatment modality for monostotic fibrous dysplasia. Hybrid fixation includes retrograde intramedullary transarticular rodding extending across the subtalar and ankle joint into the tibia and augmentation of the primary fixation with a mono-planar rail Fixation in compression mode.

Bifocal tibial corrective osteotomy with lengthening in achondroplasia: an analysis of results and complications

The results and complications of bifocal tibial osteotomies with gradual correction and lengthening by Ilizarov ring fixator performed in 47 tibiae in 24 achondroplastic patients were analyzed. Comparison was made between the parameters of angular and torsional deformities of the tibia preoperatively, at fixator removal, and at last follow-up. Of these parameters, statistically significant change was seen postoperatively in the values of medial proximal tibial angle, lateral distal tibial angle, mechanical axis deviation, and tibial torsion, which changed from 78.8 +/- 7.05 degrees, 103.2 +/- 11.8 degrees, 25.1 +/- 14.6 mm (medial), and 22.7 +/- 10 degrees (internal) preoperatively to 87.3 +/- 6.3 degrees, 90.9 +/- 5.4 degrees, 5.3 +/- 10 cm (medial), and 15.8 +/- 4.2 degrees (external), respectively, at the time of fixator removal; and this correction was maintained during the follow-up period. Mean total tibial lengthening was 6.84 +/- 1.3 cm. Average healing index was 26.06 days/cm. Complications observed were 15 pin tract infections, 1 residual varus, 1 overcorrection into valgus, 2 recurrence of varus, 22 equinus contractures, 2 premature consolidations, and 3 fibula malalignments. Recurrence of varus was observed in limbs with a residual abnormal medial mechanical axis deviation due to femoral deformity. A hundred percent incidence of equinus was observed in limbs with tibial lengthening of more than 40%, with distal tibial lengthening of more than 15%. To minimize the risk for occurrence of equinus, we recommend restriction of distal tibial lengthening in achondroplasia to less than 15%, although total tibial lengthening may exceed 40%. Fibula malalignment was not observed after double fibula osteotomy. This procedure is safe and efficacious if performed with strict adherence to prescribed technique.

MRI study of the lumbar spine in achondroplasia. A morphometric analysis for the evaluation of stenosis of the canal

We carried out an MRI study of the lumbar spine in 15 patients with achondroplasia to evaluate the degree of stenosis of the canal. They were divided into asymptomatic and symptomatic groups. We measured the sagittal canal diameter, the sagittal cord diameter, the interpedicular distance at the mid-pedicle level and the cross-sectional area of the canal and spinal cord at mid-body and mid-disc levels. The MRI findings showed that in achondroplasia there was a significant difference between the groups in the cross-sectional area of the body canal at the upper lumbar levels. Patients with a narrower canal are more likely to develop symptoms of spinal stenosis than others.

Morphometric Determinants of the Sagittal Dimensions of the Cervical Spinal Canal in Achondroplasia

This study was undertaken to evaluate the accuracy of the Torg ratio for predicting the spinal canal stenosis in achondroplasia, by trying to establish its correlation with the corresponding effective sagittal canal diameter (ESCD) and dural sac ratio (DSR) on the MRI of the cervical spine. Lateral radiographs and the sagittal and axial MRI study of the cervical spine from C3 to C7 level were carried out in 18 asymptomatic achondroplasia subjects. A total of 90 levels were evaluated on the lateral radiographs and on the mid sagittal T2 MR images. On statistic analysis, the highest correlation coefficient for the Torg ratio compared with the ESCD was 0.74 at C6 level and the least was 0.45 at the C5 level. The highest correlation coefficient between the Torg ratio and the DSR was 0.79 at C3 level and the least was 0.42 at the C5 level. The highest coefficient of determination for the ESCD was 54% at C6 which translates into a poor correlation. The highest coefficient of determination for the DSR was 62 at C3 level, indicating a variable correlation. These results clearly show that the Torg ratio is of limited value in the assessment of the true sagittal spinal canal diameter in achondroplasia and its reliability as an indicator of severe cervical canal stenosis is questionable.