Comparison of three techniques of the transarticular screw placement in the lower cervical spine / 中国骨伤

<p><b>OBJECTIVE</b>To compare three techniques of the transarticular screw placement in the lower cervical spine.</p><p><b>METHODS</b>The techniques of transarticular screw placements used by Takayasu (group A), Dalcanto (group B) and Klekamp (group C) were applied in twenty-four cervical specimens, among which 14 specimens were male and 10 specimens were female, ranging in age from 55 to 80 years, with an average of 68 years. The entry point of Takayasu technique was between the superior and median third of the vertical medial line of the lateral mass with 60 to 80 degrees caudal tilt and 0 degrees lateral tilt. Dalcanto technique started 2 mm caudal to the midpoint of lateral mass with 40 degrees caudal tilt and 20 degrees lateral tilt. Klekamp technique inserted the screws with the starting point being 1 mm medial and 1 mm inferior to the midpoint of the lateral mass with 40 degrees caudal tilt and 20 degrees lateral tilt. The splits of facets, the encroachment of the cervical nerve roots and vertebral arteries, and no-involving facets screws were observed and analyzed.</p><p><b>RESULTS</b>One hundred and ninety-two transarticular screws were implanted on both sides in twenty-four cervical cadavers, sixty-four for each group. There were twenty-five splits of inferior facets in group B, 2 splits in group C and none in group A. No superior facets were found to be broken in all cases. The difference of splits between group B and the other two groups was significant (Chi2AB = 31.07, P < .001; Chi2BC = 24.83, P < 0.01), while there was no statistical difference between group A and C (Chi2AC = 2.03, P > 0.05). Thirty-six screws encroached the vertebral arteries in group A, none in group B and C. There was significant statistical difference between group A and the other two groups (Chi2AB = 50.09, P < 0.01; Chi2AC = 50.09, P < 0.01). Forty anterior branches of lower cervical nerve roots were involved in group A, five in group B and three in group C. There were statistical differences between group A and the other two groups (Chi2AB = 41.98, P < 0.01; Chi2AC = 47-94, P < 0.01), and there was no statistical difference between group B and C. Sixteen posterior branches of lower cervical nerve roots were encroached in group A, 18 in group B and 14 in group C. There was statistical difference among the three groups (Chi2AB = 0.16, P > 0.05; Chi2AC = 0.17, 0.05; Chi2 = BC = 0.67, P >0.0 ). Although all screws went through facets in the study except for 5 in group A, there were no statistical differences between each groups Chi2AB k =3.33, P >0.05; X2A C =3.33, P> 0.05).</p><p><b>CONCLUSION</b>There are high risk of injury of anterior branch of cervical nerve root and vertebral artery if the screws are too long and the Takayasu's technique is used. However, the rate of facet split is high if the Dalcanto's technique is applied. Klekamp's technique is value to be applied.</p>

Comparison of two techniques of the transarticular screw placement in the lower cervical spine / 中国骨伤

<p><b>OBJECTIVE</b>To compare two techniques of the transarticular screw placement in the lower cervical spine, and to suggest and confirm a new technique of the placement.</p><p><b>METHODS</b>The techniques of transarticular screw placements used by Takayasu (group A) and Dalcanto (group B) were applied in eight cervical specimens. The splits of facets,the encroachment of the cervical nerve roots and transverse foramens were observed and analyzed. The numbers of transarticular screws which not gone through the facets were counted in both group A and B, respectively.</p><p><b>RESULTS</b>Sixty-four transarticular screws were implanted,thirty-two for group A, the same for group B. Although no splits of the facets were seen in group A, two transarticular screws did not go through the facets. There were ten splits of facets in group B, in which seven involved the inferior border of the inferior facets and three for the lateral border. No superior facets were found to be broken both in group A and B. Eight screws encroached the transverse foramens in group A and none in group B. Eleven of anterior branch and eight of posterior branch of lower cervical nerve roots were involved in group A, two and nine respectively in group B.</p><p><b>CONCLUSION</b>There are high risk of injury of anterior branch of cervical nerve root and vertebral artery if the screws are too long and the Takayasu's technique is used. However, the rate of facet split is high if the Dalcanto's technique is applied.</p>

An imaging study on location of the anterior border of facets and the posterior border of vertebral bodies in lower cervical spine / 中国骨伤

<p><b>OBJECTIVE</b>To explore the location of the anterior border of facets and the posterior border of vertebral bodies in lower cervical spine,and to provide a quantitative data to evaluate the correct length of transarticual screws in lower cervical spine during procedure.</p><p><b>METHODS</b>One hundred standard lateral X-ray films and fifty CT films on cervical spine were used to measure the distance of the anterior border of facets and the posterior border of vertebral bodies in lower cervical spine. HS, HM and HI were defined as parameters, which means the distance between the anterior border of the superior (HS), median (HM) and inferior (HI) part of facets and the posterior border of corresponding vertebral bodies. The value will be negative if the anterior border of the facet located before the vertebral body.</p><p><b>RESULTS</b>'HS > HM > HI' was found in all facets in lower cervical spine. The anterior border of the facet in C(3,4) located before the posterior border of the vertebral body of C3. The anterior border of C(4,5) and C(5,6) was inclined to posterior. The anterior border of C(6,7) located after the posterior border of the vertebral body of C6. The pattern of HS increased from C(3,4) to C(6,7), the minimal (0 +/- 0.25) mm and the maximal (2.91 +/- 1.05) mm. The tendency of HM raised from C(3,4) to C(6,7), the minimal (-1.57 +/- 0.53) mm and the maximal (1.54 +/- 0.39) mm. The pattern HI added from C(3,4) to C(6,7), the minimal (-2.03 +/- 0.40) mm and the maximal (1.08 +/- 0.70) mm.</p><p><b>CONCLUSION</b>During the implantation of the transarticular screws, the tip of the screws should be 0-2 mm before the posterior border of the vertebral body of C3 at C(3,4), 0-2 mm after that of C4 at C(4,5), 0.5-2.5 mm at C(5,6) and 1-3 mm at C(6,7). The quantitative location between the anterior border of facets and the posterior border of the corresponding vertebral bodies can offer an indirect method to evaluate the correct length of transarticual screws in lower cervical spine during procedure.</p>

Percutaneous lag screw internal fixation of LX technique for the sacroiliac joint injury / 中国骨伤

<p><b>OBJECTIVE</b>To study the percutaneous lag screw internal fixation of LX technique for sacroiliac joint diseases or injuries.</p><p><b>METHODS</b>There were 38 patients (25 male and 13 female) with an average age of 35.6 years ranged from 18 to 59 years. Among them, thirty-one cases with trauma of Tile B type, five cases with sacroiliitis and two cases with sacral cystis degeneration. There were 11, 15, 5 cases of Tile B1, B2, B3 type respectively. Pelvic anterior-posterior radiography and spiral computed tomography (CT) were undertaken for all patients. Axis planar, coronal planar, sagittal planar and curve planar of sacral reconstruction of spiral CT images were obtained for every patient. There were 28 cases with delitescence posterior ring injury. All these patients were performed percutaneous lag screw fixation procedures of LX technique under epidural anesthesia. Localization with spiral CT guidance was performed by the radiologist using spiral CT followed by the orthopaedic surgeon. Percutaneous fusion of sacroiliac joint was performed for seven patients who suffered from sacroiliac joint diseases.</p><p><b>RESULTS</b>The blood loss were from 25 to 70 ml (means 36 ml) during operation. All patients were followed up for 3 to 39 months (means 15.6 months). There were no postoperative complications such as infection, fracture nonunion, iatrogenic injuries of nerve and blood vessel, breakage and slippage of fixtors. According to the evaluation of pelvic injuries, the results of imageology were excellent in 34 cases and good in 4, the results of clinical were excellent in 32 and good in 6.</p><p><b>CONCLUSION</b>Percutaneous lag screw internal fixation of LX technique minimizes operation injury during a short procedure with few subsequent complications and allows early mobilization of the patients. That is an ideally safe and effetive operation technique for the sacroiliac joint diseases and injuries.</p>