Subacute steroid-induced paraparesis: surgical treatment of a devastating "invisible" side effect.

PURPOSE: To emphasize an underestimated side effect following long-term use of steroids. METHODS: We report on surgical treatment of two patients with serious neurologic deficits caused by epidural spinal lipoma following long-term intake of cortisone. RESULTS: Early decompression of the spinal cord by removal of epidural lipoma was the most effective treatment in these patients with progressive symptoms. CONCLUSION: Diagnostic work-up of such patients should include early spinal MRI resulting in surgical intervention, if indicated. Decompression of the spinal cord eventually combined with fusion is necessary.

3D visualized robot assisted reduction of femoral shaft fractures: evaluation in exposed cadaveric bones.

The main problems in intra-medullary nailing of femoral shaft-fractures are leg-length discrepancies and rotational differences with an incidence of 2-18% and 20-40% respectively. These may lead to severe postoperative sequelae such as additional correctional operations and difficult rehabilitation. Insufficient visualization can be considered the main reason for these complications. Finally, retention of the fragments in the correct alignment before nail insertion is difficult. To overcome these problems we established a robotic telemanipulator system to support the reduction process. It was evaluated in 30 fractures of embalmed human femora. Specially programmed software used an image-dataset which was acquired by an isocentric 3D fluoroscope. For visualization, a surface projection was generated. Localization and tracking of the fragments and the robot-arm as well as accuracy measurement was performed by using an optical navigation system. Manipulation was controlled via a force-feedback joystick. This way, collisions of the fragments were transmitted back to the surgeon. At the end of the reduction the robot could rigidly retain the fragments' position.

The accuracy and precision of computer assisted surgery in the assessment of frontal plane deviations of the lower extremity: a femoral fracture model.

OBJECTIVES: Mechanical axis deviation of the lower extremity as a result of malreduction or malunion of fractures plays an important role in the development of arthritis. Therefore it is crucial to restore the limb alignment as accurate as possible. The purpose of this study was to evaluate the accuracy and precision of navigation in assessing isolated frontal plane (varus/valgus) deviations of the lower limb in a simulated fracture model of the femur. MATERIALS AND METHODS: Three fracture models with ten specimens in each were created in femoral synthetic composite bones to simulate a subtrochanteric (AO/OTA 31-A1), mid-diaphyseal (AO/OTA 32-A3), and supracondylar (AO/OTA 33-A1) femur fracture. Each specimen was mounted on a custom holding device and registered with the navigation system. Eight custom-made aluminum wedges of varying angles (5 degrees -26 degrees ) were used to create varus/valgus angulations at the fracture site. After wedge placement, the frontal plane deformity was recorded and registered by the navigation system. The means and standard deviations for each navigated wedge angle were calculated and compared to the actual wedge angle using a one sample t test. A single factor ANOVA test was subsequently performed to see if the differences between the navigated mean angles in each fracture group were statistically significant. The level of significance was defined as P < 0.05. RESULTS: None of the navigated mean angles were found to be significantly different from the actual wedge angles (P = 0.05-1.00). More specifically, the differences between the navigated mean angles and the actual wedge angles ranged from 0 degrees to 0.7 degrees . Furthermore, the differences between the navigated mean angles in each angle group were found to be statistically insignificant (P = 0.53-0.99). CONCLUSION: The high accuracy and precision of navigation systems in determining frontal plane deformities of long bones can make them an invaluable tool for the exact reduction and realignment of lower extremity fractures.

Chopart joint fracture-dislocation: initial open reduction provides better outcome than closed reduction.

Injury cause, treatment, and long-term results [American Orthopaedic Foot and Ankle Society (AOFAS) Midfoot Score, Hannover Scoring System, Hannover Outcome Questionnaire] of patients with Chopart joint dislocations or fracture-dislocations were evaluated. Between 1972 and 1997, 100 patients with 110 Chopart joint dislocations were treated in the authors' institution. Pure Chopart joint dislocations were observed in 28 (25%) feet, fracture-dislocations in 60 (55%) feet, and combined Chopart-Lisfranc joint fracture-dislocations in 22 (20%) feet. The primary treatment was operative in 91 (83%) feet and nonoperative in 19 (17%) feet. Sixty-five (65%) patients had follow-up after an average of 9 years (range, 2-25 years). The mean scores of the entire follow-up group were: AOFAS score, 75 points; Hannover Scoring System, 69 points (maximium possible score = 100 points); Hannover Outcome Questionnaire, 68 points (maximium possible score = 100 points). There were no differences between the scores for pure dislocations or fracture-dislocations of the Chopart joint, but significantly lower scores were noted with combined Chopart-Lisfranc joint fracture-dislocations. In all three injury pattern groups, an initial anatomic reduction was essential for good results. The high functional restrictions in Chopart dislocations can most likely be minimized with initial open reduction, especially in fracture-dislocations. A closed reduction yielded good results only with pure dislocations, when anatomic conditions could be restored, or if there were contraindications to surgery.