Sacral plexus

Abstract: 1. INTRODUCTION Terminology Terms used in describing movement Nervous system Components of the musculoskeletal system Skin and its appendages Early embryology 2. THE UPPER LIMB Introduction Development of the musculoskeletal system Bones Muscles Joints Nerve supply Blood supply Lymphatics 3. THE LOWER LIMB Introduction Development of the musculoskeletal system Bones Muscles Joints Nerve supply The sacral plexus Blood supply Lymphatics 4. THE TRUNK AND NECK Introduction Bones Muscles Joints Nerve supply The cardiovascular system The respiratory system The digestive system The urogenital system The endocrine system 5. HEAD AND BRAIN Bones Muscles Joints The ear, eye and brain INDEX

Abstract: Study design Retrospective evaluation of 19 consecutive patients with sacral fracture dislocations and cauda equina syndrome. Objective To review the safety and patient impact of early surgical decompression, and rigid segmental stabilization in patients with high-grade sacral fracture dislocations. Summary of background data The ideal treatment for patients presenting with fracture dislocations of the sacrum resulting from high-energy mechanisms remains unknown. Previous studies consisted of multicenter case reviews that showed satisfactory outcomes with either nonoperative or a variety of surgical methods. However, over the last 20 years, no consistent treatment algorithm for these severe injuries has emerged. The advent of rigid, low-profile segmental fixation of the lumbar spine to the pelvic ring has offered a solution to many of the surgical challenges. This study evaluates the rate of complications of this method. It is intended to serve as a foundation for further evaluation and development of this treatment strategy, and as a basis for future comparison studies. Methods Patients were treated with a formally established algorithm, including resuscitation, and clinical assessment with detailed neurologic assessment and radiographic workup with pelvic computerized tomography and reformatted views. Electrophysiologic testing was conducted to confirm the presence of sacral plexus injuries in patients who were unable to be examined. Patients received neural element decompression and open reduction with segmental internal fixation through a midline posterior approach by connecting lower lumbar pedicle screws to long iliac screws when the patient's general medical condition allowed for surgical intervention. A formal sacroiliac arthrodesis was not performed. For the purposes of this study, patients were assessed specifically for the following adverse events: (1) infection, (2) wound healing, (3) neurologic deterioration following surgical treatment, (4) postoperative loss of sacral fracture reduction, (5) instrumentation failure, (6) axial lumbopelvic pain requiring further treatment, and (7) unplanned secondary surgery. Results There were 19 patients with an average age of 32 years treated according to this algorithm. Fracture reduction was successfully maintained in all patients. During the index surgical intervention, 14/19 patients (74%) had had either a traumatic dural tear or nerve root avulsion. Major complications involved fracture of the connecting rods in 6/19 patients (31%) and wound healing disturbances in 5/19 (26%). There were no lasting complications such as chronic osteomyelitis noted. In patients followed over a 1-year period, the visual analog score, referable to the sacral injury, averaged 5.5 on a scale of 0-10. Conclusions Rigid segmental lumbopelvic stabilization allowed for reliable fracture reduction of the lumbosacral spine and posterior pelvic ring, permitting early mobilization without external immobilizaton and neurologic improvement in a large number of patients. Complications were primarily related to infection, wound healing, and asymptomatic rod breakage, and were without long-term sequelae.

Abstract: In 21 normal subjects, far-field somatosensory potentials were recorded from the scalp after stimulation of the tibial nerve at the ankle (tibial SEP). With the use of a knee reference contralateral to the side of stimulation, the tibial SEP consisted of three major positive peaks, P17, P24, and P31, and three additional but inconsistent components, P11, P21, and P27. Presumable generator sources of the tibial SEP are the popliteal fossa for P11, entry to the sacral plexus for P17, the cauda equina for P21, entry to the conus medullaris for P24, the rostral spinal cord for P27, and the brainstem for P31.