This study was carried out to identify the distinguishing features of brucellosis on magnetic resonance imaging (MRI). MRI examinations were performed in 14 patients with spinal brucellosis. A 1-T Magnetom (Erlangen, Siemens) was used to obtain T1-weighted (TR/TE 500/30) and T2-weighted (TR/TE 2000/80/20) spin echo sequences, in both sagittal and axial planes. Thirty-three percent of the vertebrae and 18 levels of disc were involved in the 14 brucellar spondylitis cases. Eleven patients (79.8%) with discitis revealed anterior superior vertebral body involvement. Fourteen (77.7%) of the levels with discitis displayed soft tissue swelling without presence of abscess formation. Seven facet joints of five patients with discitis displayed signal increase after contrast enhancement. Vertebral body signal changes without morphologic changes marked signal increase in the intervertebral disc on T2-weighted and contrast-enhanced sequences, and soft tissue involvement without abscess formation can be accepted as specific MRI features of brucellar spondylitis. The facet joint signal changes following contrast enhancement is another MRI sign of spinal brucellosis, which has not been mentioned so far.

No abstract

A 15-year-old boy presented with an extremely rare optochiasmatic cavernous angioma. He was admitted to a special hospital with the complaint of blurred vision persisting for 1 month. Magnetic resonance imaging and biopsy of the lesion were inconclusive. He was admitted to our neurosurgical clinic after worsening of the visual symptoms 9 months later. Repeat magnetic resonance imaging showed optochiasmatic cavernous angioma which had doubled in size. The lesion was removed completely without any problem. Postoperatively his visual complaints remained stable, but had improved after 1 year. Optochiasmatic cavernous malformation should be treated by surgical excision, whereas biopsy is useless and may result in enlargement.

Object An in vitro flexibility experiment was performed to compare the biomechanical stability of asymmetrical lumbar pedicle screw fixation (longer hardware attached ipsilaterally to a 1-sided lesion), short and long fixation, and fixation with and without interconnection to the involved vertebra. Methods Seven human cadaveric specimens (T12–S1) were studied intact; after simulated unilateral lesions were created at L2–3 and L3-4, the segments were stabilized by 1) L2–4 unilateral fixation (L-3 excluded), 2) L2–4 bilateral fixation (L-3 included contralaterally), 3) L2–5 unilateral fixation (L-3 excluded), 4) L2–5 fixation ipsilateral (L-3 excluded) and L2–4 fixation contralateral (L-3 included), 5) L2–5 bilateral fixation (L-3 included contralaterally), and 6) L2–5 bilateral fixation (L-3 excluded). The testing order varied among specimens. Angular range of motion (ROM) and lax zone were recorded optically while loading to 6.0 Nm was created with nonconstraining pure moments. Results Unilateral short fixation provided significantly worse stabilization than any other construct tested in all loading modes (p < 0.05, repeated-measures analysis of variance). There was a mean 56% reduction in ROM across the lesion after adding 1 additional level rostrally and caudally. Asymmetrical long/short stabilization provided similar stability to symmetrical long stabilization. Minimal additional stability was gained by including L-3 in the long bilateral fixation construct. Conclusions Unilateral fixation is inadequate for stabilizing a 2-level unilateral lesion. Bilateral fixation, whether symmetrical or asymmetrical, provides good stabilization for this injury. It is not important for stability to include the level of the lesion within the long construct contralaterally.

Object Cervical total disc replacement has emerged as a surgical option to preserve motion and potentially avoid adjacent-segment disease after anterior cervical discectomy and fusion. Recently, much attention has been directed at the ability of a given device to maintain and/or restore normal segmental alignment. Nonphysiological disc and segmental angulation could result in increased stresses transmitted to the facet joints and posterior elements, conflicting with the essence of arthroplasty and potentially leading to adjacent-segment disease. The goal of this study was to contrast device alignment and segmental kinematics provided by 3 different cervical disc prostheses. Methods Sixty patients were retrospectively analyzed and divided into 3 groups receiving the Bryan, ProDisc-C, or Synergy disc. Only single-level arthroplasty cases were included in the study. Lateral dynamic radiographs of the cervical spine were analyzed using quantitative motion analysis software (Medical Metrics, Inc.) to analyze the kinematics at the index level both preoperatively and postoperatively. Several parameters were noted, including range of motion, disc angles, shell angles, anterior and posterior disc heights, translation, and center of rotation. Preoperative and postoperative data were compared using the Student t-test with a significance level of p < 0.05. Results Postoperatively, all 3 disc groups maintained adequate range of motion at the implanted level. With respect to the shell angles, the Synergy disc demonstrated the least variability, maintaining 6° lordotic configuration between the device endplates. In the Bryan disc group, significant shell kyphosis developed postoperatively (p < 0.0001). Both ProDisc-C and Synergy discs significantly increased anterior and posterior disc heights (p < 0.0001). The Bryan and Synergy discs maintained the natural center of rotation, whereas significant anterior shift occurred with ProDisc-C. Conclusions The goal for motion preservation at the implanted level was achieved using all 3 devices. The Synergy disc was unique in its ability to alter device angulation by 6°. The Bryan disc demonstrated device endplate kyphosis. Both the Synergy disc and ProDisc-C increased disc space height.