Danger of damaging the medial branches of the posterior rami of spinal nerves during a dorsomedian approach to the spine.

Postoperative atrophy of the deep back muscles may be caused by denervation during a dorsomedian approach to the thoracolumbar spine; ensuing instability of the spine with poor clinical results, perhaps due to such muscle loss, has been observed in 11.7% of cases (Sihvonen et al., 1993, Spine 18:575--581). More specifically, this complication may be caused by damaging the medial branches of the posterior rami of the spinal nerves during lateral retraction of the muscles. To investigate the anatomic topography of the medial branches of the posterior rami of the spinal nerves, 18 carbol-formol-fixed specimens were dissected using an operation microscope; also, 3 fresh cadavers were cut in horizontal and vertical planes with a rotary cryotome to confirm the anatomic topography observed in the fixed specimens. In the thoracolumbar spine the medial branch of the posterior ramus of the spinal nerve is subject to ligamentous fixation by the strong fibers of the mammillo-accessory ligament, which extends between the mammillary process and accessory process infero lateral to the superior articular process. When the dorsomedian approach to the thoracolumbar spine is enlarged laterally to the articular processes by retracting the paraspinous muscles, the medial branches of the posterior rami of the spinal nerves are endangered. This may cause postoperative pain as well as dynamic instability beyond the corresponding segments. The results of our anatomic study suggest that the posterior surgical midline approach to the thoracolumbar spine should not be enlarged laterally to the articular processes to prevent injury to the medial branches of the posterior rami of the spinal nerves.

[Management of injuries of the thoracic and lumbar vertebrae in children]. / Die Behandlung von Verletzungen der Brust- und Lendenwirbelsäule bei Kindern.

Traumatic injuries of the thoracic and lumbar spine are rare in children and differ in pathomorphology, healing process and prognosis from those in adults. Before growth arrest the vertebral epiphysis has an important role in pathomorphology and prognosis; therefore, treatment should recognize the age-dependent potential for growth and remodelling. This study demonstrates the different anatomic and pathomorphologic characteristics of traumatic spinal injuries in 40 children. Additionally, prognosis and the various forms of treatment are discussed in the context of the recent literature. In total we observed 85% compression-type injuries and 15% distraction- and rotation-type injuries. Vertebral body fractures were treated conservatively and segmental disruptions by fusion. Long-term follow-up was performed on average 8 years after the accident in 26 patients clinically and in 21 patients radiologically. Most patients had no physical complaints or clinical symptoms. Additionally, the radiographs did not demonstrate any post-traumatic defects. In summary, spinal injuries up to the age of 12 without initial neurologic symptoms have a favorable prognosis.

Treatment of injuries of the thoracic and lumbar spine in children.

Traumatic injuries of the thoracic and lumbar spine are rare in children and differ in pathomorphology, healing process and prognosis from those in adults. Before growth arrest the vertebral epiphysis has an important role in pathomorphology and prognosis; therefore, treatment should recognize the age-dependent potential for growth and remodelling. This study demonstrates the different anatomic and pathomorphologic characteristics of traumatic spinal injuries in 40 children. Additionally, prognosis and the various forms of treatment are discussed in the context of the recent literature. In total we observed 85 % compression-type injuries and 15 % distraction- and rotation-type injuries. Vertebral body fractures were treated conservatively and segmental disruptions by fusion. Long-term follow-up was performed on average 8 years after the accident in 26 patients clinically and in 21 patients radiologically. Most patients had no physical complaints or clinical symptoms. Additionally, the radiographs did not demonstrate any post-traumatic defects. In summary, spinal injuries up to the age of 12 without initial neurologic symptoms have a favorable prognosis.

Metallic artifacts in magnetic resonance imaging of patients with spinal fusion. A comparison of implant materials and imaging sequences.

STUDY DESIGN: Devices for spinal fusion were compared with respect to their influence on magnetic resonance images. In addition, different magnetic resonance pulse sequences were evaluated to elicit their susceptibility to imaging artifacts. OBJECTIVES: To determine the implants with the least imaging artifacts as a recommendation for the spine surgeon and to assess the best imaging strategy for the radiologist. SUMMARY OF BACKGROUND DATA: For patients who have had surgical spinal fusion with instrumentation, magnetic resonance imaging is the most favorable diagnostic method. Unfortunately, metallic implants lead to severe degradation of image quality. These artifacts depend on the material of the implant and on the choice of the pulse sequence. METHODS: The fusion devices were mounted on a simple plastic phantom in various combinations and were imaged on 1.5-T magnetic resonance units. Frequently used types of plates and screws made of titanium or steel in various alloys were examined on the phantom with routinely used pulse sequences. The results of these examinations were compared with those in patient studies involving the same implants as well as the same pulse sequences. RESULTS: The least imaging artifacts were caused by titanium implants, especially when using shorter screws, wider screw placement, and thinner titanium plates. Nevertheless, there were distinct image distortions that could lead to erroneous image interpretation. The best images were acquired by spin echo (T1), turbo spin echo (T1, T2), and half Fourier single shot turbo spin echo (HASTE) sequences. Sequences containing any gradient echo components (gradient echo or turbo gradient and spin echo sequence or frequency-selective fat saturation techniques) resulted in the highest amount of image degradation. CONCLUSION: By choosing appropriate spinal fusion devices as well as pulse sequences, postoperative magnetic resonance imaging examinations can give acceptable results, in spite of the presence of metallic implants.

[Magnetic resonance tomography in spinal trauma]. / Magnetresonanztomographie beim spinalen Trauma.

PURPOSE: To assess the value of MR imaging in the acute and chronic stages of spinal trauma. METHODS: 126 MR examinations of 120 patients were evaluated retrospectively. In 15 cases of acute spinal cord injury, correlation of MR findings with the degree of neurological deficit and eventual recovery was undertaken. RESULTS: Cord anomalies in the acute stage were seen in 16 patients. Intramedullary haemorrhage (n = 6) and cord transection (n = 2) were associated with complete injuries and poor prognosis, whereas patients with cord oedema (n = 7) had incomplete injuries and recovered significant neurological function. In the chronic stage, MR findings included persistent cord compression in 8 patients, syringomyelia or post-traumatic cyst in 12, myelomalacia in 6, cord atrophy in 9, and cord transection in 7 patients. CONCLUSION: In acute spinal trauma, MR proved useful in assessing spinal cord compression and instability. In addition, direct visualisation and characterisation of post-traumatic changes within the spinal cord may offer new possibilities in establishing the prognosis for neurological recovery. In the later stages, potentially remediable causes of persistent or progressive symptoms, such as chronic spinal cord compression or syringomyelia can be distinguished from other sequelae of spinal trauma, such as myelomalacia, cord transection or atrophy.

[The value of closed reduction of fractures of the lower thoracic and lumbar spine and computerized tomography follow-up]. / Die Wertigkeit der gedeckten Reposition bei Frakturen der unteren Brust- und Lendenwirbelsäule und ihre computertomographische Kontrolle.

The objectives of this prospective study were to investigate the value of the immediate closed reduction following fractures of the thoracolumbar and lumbar region. To reach that goal we performed a two stage CAT scan procedure before and after the reduction maneuver in a distinct patient population. The aim was not only to investigate the biomechanical process but also to evaluate and describe certain fracture types which have a good prognosis due to closed reduction according to posttraumatic spinal stenosis because of protruding posterior wall fragments and those who fail, respectively.

Application of posterior plating and modifications in thoracolumbar spine injuries. Indication, techniques, and results.

Out of 281 patients with recent injuries to the thoracic and lumbar parts of the spine, 243 underwent posterior plating. Of these, 172 patients had an average follow-up of 3.2 years. The consecutive analysis of morphologic results led to modifications of the original Roy-Camille technique. In analogy to the system developed by Zielke for anterior derotation spondylodesis, plates were used in combination with VDS screws, threaded rods, and nuts, thus creating an implant with initial angle variability but final angle stability. The development of transpedicular reduction and cancellous bone grafting for the treatment of vertebral body fractures, later supplemented by transpedicular discectomy and intercorporal cancellous bone grafting, effected a significant improvement in the results of posterior plating. Although the use of traditional plating was followed by correction losses of 14 degrees, the loss could be reduced to less than 6 degrees by the new system, which nearly corresponds to the physiologic anatomy of the spine.

Revascularization of a partially necrotic talus with a vascularized bone graft from the iliac crest.

A 16-year-old patient had a compound dislocation of the right talus. Following primary treatment, which included a subtaler screw arthrodesis, the talus developed clinical, radiological, and isotope scan signs of necrosis. In spite of a walking caliper to prevent weight bearing on the ankle, the talar articular cartilage of the ankle joint also showed signs of degeneration. The talus was revascularized with a vascularized corticocancellous iliac crest bone graft. Six months postoperatively, there were clinical, radiological, and bone scan signs of significant revascularization. The patient is free of pain and able to walk with full weight bearing on the foot.

Posterior cervical fusion with rigid internal fixation.

Rigid fixation of the posterior cervical spine offers definite advantages over conventional wiring techniques. These advantages are emphasized in certain high-risk groups of patients, including those with multiple-level traumatic instability, cervical deformities, and unresectable anterior tumor involvement. Early fusion with minimal external fixation is another important advantage. The focus of this article is the concept of rigid internal fixation of the posterior cervical spine and the application of specific techniques used to achieve this goal.

[Roentgen examination in recurrent shoulder luxation--value of different exposure technics]. / Röntgenuntersuchung bei habitueller Schulterluxation--die Wertigkeit verschiedener Aufnahmetechniken.

Clinical and radiological examination was done in 61 patients in whom a Bankart procedure had been performed. In an X-ray follow-up the value of different techniques proving the Hill-Sachs-lesion and degenerative changes of the bony glenoid rim, as described in literature, was investigated. Eight X-rays were performed in each patient. Most of the Hill-Sachs-lesions (76%) were found by internal rotation of 60 degrees in a.p. direction. A three dimensional idea can be obtained by an additional X-ray in tangential projection. Degenerative changes of the bony glenoid rim were found by the Bernageau technique in 25 percent. Standard X-ray before operation should include techniques in various projections: a.p. and simultaneous internal rotation of 60 degrees of both sides, tangential projection, and X-ray as described by Bernageau.

[Collision injuries on ski slopes (author's transl)]. / Kollisionsverletzungen auf der Schipiste.

A prospective study was carried out on ski accidents caused by collisions on ski slopes. The article defines the term "ski collision" and then reviews the authors' case histories of the last three years, taking the location and time of accident, the type of collision and injury into consideration. The authors have been able to prove that the collision type of injury differs from "normal" ski injury. The most striking difference in these injuries was found to be the increase in the frequency of visceral cranium trauma. The second difference concerns the incidence of thoracoabdominal injuries. The authors have attempted to point out a few prophylactic measures. A brief discussion deals with problems involving "slope regulations". Finally, the authors urgently recommend, in view of the risk of fatal injuries in collision accidents, to ensure quickest possible and careful transportation of accident victims to a versatile and well-equipped hospital.