Outcomes of posterior C(1-2) fusion for atlantoaxial instability or dislocation using pedicle screws of atlas and axis / 中华外科杂志

<p><b>OBJECTIVE</b>To retrospectively analyze and evaluate the results of treatment for atlantoaxial instability or dislocation employing pedicle screws of atlas and axis.</p><p><b>METHODS</b>Thirty-one patients (23 male and 8 female) with atlantoaxial instability or dislocation were stabilized using pedicle screws of atlas and axis between May 2005 to January 2008. The patients ranged in age from 17 to 67 years (mean 43.5 years). Patients consisted of chronic odontoid fracture in 17, Os odontoideum in 8, fresh odontoid fracture in 4, transverse ligament rupture in 1, rheumatoid arthritis in 1. Clinical features included neck pain in 31; restricted neck movement in 28, varying degrees of spastic quadriparesis in 19. All patients underwent posterior C(1) to C(2) pedicle screw fixation. Operative time, intraoperative blood loss, complications were recorded, neurological and radiographic studies were carried.</p><p><b>RESULTS</b>Mean follow-up time was 13 months. Operative time averaged 2.5 h. Mean intraoperative blood loss was 300 ml. A patient had postoperative wound infection and was treated conservatively with antibiotics and local wound care. A patient developed pulmonary artery embolism and got well with anticoagulation. Satisfactory stability was achieved in all cases with no vascular and C(2) neuralgia. Average JOA score in 19 cases increased at final follow-up (P < 0.01). Solid fusion was achieved in 29 cases, fusion rate was 93.6%.</p><p><b>CONCLUSIONS</b>Stabilization of atlantoaxial complex via pedicle screws of atlas and axis has advantages of intraoperative restoration, easier placement of screw, solid fixation. It is a safe and effective treatment modality for posterior C(1-2) fusion.</p>

Accuracy and related affecting factors of somatosensory evoked potential monitoring in cervical and thoracic surgery / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the accuracy and related affecting factors of the intra-operative somatosensory evoked potential monitoring in cervical and thoracic surgery.</p><p><b>METHODS</b>Cortical somatosensory evoked potential (CSEP) monitoring and sub cortical somatosensory evoked potential (Sub-CSEP) monitoring were performed in cervical and thoracic surgery. Somatosensory evoked potential (SEP) changes were recorded during anaesthesia and operation and postoperative, which could be used to evaluate accuracy of SEP.</p><p><b>RESULTS</b>Bilateral CSEP wave abnormalities were related to anaesthesia, decreasing wave amplitudes did not reach the alarming standard. Intra-operative manipulation to affect spinal cord would influence iso-lateral wave abnormality of CSEP and sub-CSEP, decreasing amplitudes reached the alarming standard. Local hypothermia such as cold water irrigating spinal cord would be to prolong the latent period. Low mean arterial pressure (MAP) mostly influenced amplitudes. Changes of SEP in local hypothermia and MAP did not reach the alarming standard.</p><p><b>CONCLUSIONS</b>CSEP and Sub CSEP can reflex physiopathological condition of spinal cord, it is useful in evaluating spinal cord function and providing the safety for cervical and thoracic surgery.</p>

Gene expression of collagen types IX and X in the lumbar disc / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To study gene expression of collagen types IX and X in human lumbar intervertebral discs during aging and degeneration and to explore the role of collagen types IX and X in disc degeneration.</p><p><b>METHODS</b>Fetal, adult and pathologic specimens were subjected to in situ hybridization with cDNA probes to investigate mRNA-expressions of types IX and X collagen gene.</p><p><b>RESULTS</b>In fetal intervertebral discs, positive mRNA hybridization signals of type IX collagen were concentrated in the nucleus pulposus and the inner layer of anulus fibrosus. Interstitial matrix of the nucleus pulposus also showed positive type X collagen staining. Positive mRNA hybridization signals of types IX and X were not detected in the middle and outer layers of anulus fibrosus. In adult specimens, expression of type IX collagen mRNA was markedly decreased. No hybridization signals of type X collagen was observed. As for pathological specimens, there was no gene expression of type IX collagen. In severe degenerated discs from adults, there were focal positive expressions of type X collagen.</p><p><b>CONCLUSIONS</b>Obvious changes of collagen gene expression occur with aging. Expression of type IX collagen decreases in adult and pathological discs. Results of type X collagen expression suggest that type X collagen is expressed only in older adult and senile discs (i.e., when disc degeneration has already reached a terminal stage), indicating the terminal stage of degeneration.</p>