Influence of patient axial malpositioning on the trueness and precision of pelvic parameters obtained from 3D reconstructions based on biplanar radiographs.

OBJECTIVES: Radiographs are often performed to assess pelvic and hip parameters, but results depend upon correct pelvis positioning. Three-dimensional (3D) reconstruction from biplanar-radiographs should provide parameters that are less sensitive to pelvic orientation, but this remained to be evaluated. METHODS: Computerized-tomographic scans of six patients were used both as a reference and for generating simulated frontal and lateral radiographs. These simulated radiographs were generated while introducing axial rotations of the pelvis ranging from 0° to 20°. Simulated biplanar-radiographs were utilized by four operators, three times each, to perform pelvic 3D-reconstructions. These reconstructions were used to assess the trueness, precision and global uncertainty of radiological pelvic and hip parameters for each position. RESULTS: In the neutral position, global uncertainty ranged between ± 2° for pelvic tilt and ± 9° for acetabular posterior sector angle and was mainly related to precision errors (ranging from 1.5° to 7°). With increasing axial rotation, global uncertainty increased and ranged between ± 5° for pelvic tilt and ± 11° for pelvic incidence, sacral slope and acetabular anterior sector angle, mainly due to precision errors. CONCLUSION: Radiological parameters obtained from 3D-reconstructions, based on biplanar-radiographs, are less sensitive to axial rotation compared to plain radiographs. However, the axial rotation should nonetheless not exceed 10°. KEY POINTS: • Pelvic radiological parameters could be affected by patient malpositioning. • Biplanar radiograph-based 3D reconstructions were performed at increments of axial rotation. • Trueness, precision and global uncertainty were evaluated for pelvic and hip radiological parameters. • Hip parameters were less affected by rotation compared to pelvic parameters. • Maintaining the pelvis close to the neutral position is recommended to ensure the highest possible accuracy.

Aneurysmal Bone Cyst of the Cervical Spine in Children: A Review and a Focus on Available Treatment Options.

OBJECTIVE: To present a series of pediatric cervical spine (CS) aneurysmal bone cysts (ABC), to review the literature, and to propose a treatment algorithm. MATERIAL: We present a series of 4 cases of ABC and review the literature using PubMed, EMBASE, and Google scholar. RESULTS: Only 51 cases are documented. The mean age at diagnosis is 11.5 years, and there is a small female predominance (F:M ratio=1.6). Most of ABC occurs in the upper CS (41%), are located in the posterior component (75%), and extends in 40% of the vertebral body. A single treatment modality was used in 56.9%, whereas combination of surgery with other treatment modalities was used in the rest. Of the total number of cases, 56.8% were managed with marginal resection, and instrumentation was used in 80%. Mean follow-up was 72.5 months, with the majority of patients disease free. Pain is the most common symptom present at the latest follow-up. CONCLUSIONS: ABC of the spine is a pediatric tumor occurring rarely in the CS. Treatment options vary from simple curettage to total resection with or without instrumentation. Recurrence after surgery is highest after curettage alone. The main indications for surgery are rapid progression, despite intracystic injection, and/or the presence of neurological signs or symptoms.

Congenital costo-vertebral fibrous band and congenital kyphoscoliosis: a previously unreported combination.

Congenital kyphoscoliosis (CKS) results from abnormal vertebral chondrification. Congenital fibrous bands occur in several locations with variable impact on vertebral development. We report a previously unreported case of a female infant with CKS presenting with an L2 hypoplastic vertebra and a costo-vertebral fibrous band extending to the skin in the form of a dimple. We also describe the therapeutic approach, consisting of surgical excision of the fibrous band and postoperative fulltime bracing, with a 7-year follow-up. We recommend a high index of suspicion in any unusual presentation of CKS and insist on case by case management in such cases.

[Brain tumors and epilepsy: postoperative evaluation of surgical procedures]. / Evolution postopératoire de l'epilepsie chez les patients opérés de tumeurs cérébrales.

OBJECTIVES: To study the efficacy of surgery on the postoperative control of epilepsy in patients operated for brain tumors. METHODS: Forty patients operated for supratentoriel cerebral tumors with epilepsy, at Hotel-Dieu de France (HDF) hospital center, between 1983 and 2005, were included in this study. Clinical, paraclinical and surgical information were collected. The extent of the tumor resection was based on the postoperative MRI results. RESULTS: The mean duration of the follow-up was 52 +/- 6 months (from 6 months to 10 years). 62.5% of our patients have had acute seizures (< 1 year) and 37% had experienced chronic seizures (> or = 1 year). The histopathologic exam revealed 2 DNET, 3 pilocytic astrocytomas, 2 diffuse astrocytomas, 6 A oligodendrogliomas, 7 B oligodendrogliomas, 7 anaplastic astrocytomas and glioblastomas and 13 meningiomas. Twenty-two patients had a complete resection, whereas the postoperative MRI of 18 patients have shown a tumoral remnant. After one year of follow-up, a complete remission was noted in 57.5% of the patients (Engel I). The prognostic factors of good outcome were: low-grade glial tumors (I +/- II), meningiomas, and complete tumor resection. CONCLUSION: The efficacy of surgery for epilepsy associated to cerebral tumors, established by the majority of articles, matched the results obtained for the patients operated at HDF, with complete seizures control in 57.5% of patients. This control depended essentially on the extent of tumor resection and on tumor's nature.