Wiltse approach combined with contralateral transforaminal lumbar interbody fusion and conventional surgery for lumbar disc herniation:a case-control study / 中国骨伤

OBJECTIVE@#To compare the clinical effecty of Wiltse approach combined with contralateral transforaminal lumbar interbody fusion (TLIF) and traditional TLIF in the treatment of lumbar disc herniation and its affect on injury of multifidus muscle.@*METHODS@#From June 2014 to September 2017, 90 patients with lumbar disc herniation combined with lumbar spine instability were divided into two groups (Wiltse approach group and traditional group) depend on the procedure of operation. Wiltse approach group was treated with Wiltse approach screw placement in one side combined with contralateral TLIF. There were 50 patients in Wiltse approach group, including 36 males and 14 females, aged 45 to 72 yearswith an average of (60.4± 3.1) years. The traditional group was treated with traditional TLIF operation. There were 40 patients in the traditional group, including 25 males and 15 females, aged 45 to 74 years with an average of (62.1±3.4) years. The operative time, intraoperative blood loss, accuracy of screw implantation, postoperative drainage volume and drainage tube removal time were recorded in two groups. Visual analogue scale (VAS) and Oswestry Disability Index (ODI)were observed before and 12 months after operation. All patients underwent CT examination preoperative and 12 months postoperative, and the CT values of bilateral multifidus muscle were measured.@*RESULTS@#All the patients were followed up, 40 patients in traditional group were 12 to 18 months with an average of (15.3±4.3) months; and 50 patients in Wiltse approach group were 13 to 24 months with an average of (16.5± 4.1) months. There were no statistically significant differences in operative time and intraoperative blood loss between two groups (@*CONCLUSION@#Compared with traditional surgical procedures, the Wiltse approach nail placement combined with contralateral TLIF has the advantage of accurate nail placement, reducing multifidus muscle damage, and reducing the incidence of postoperative intractable low back pain.

Comparison of the accuracy of three methods for determining maxillomandibular horizontal relationship of the complete denture / 华西口腔医学杂志

OBJECTIVE@#To observe the changes of forward displacement of maxillary complete denture during centric occlusion, three different methods were used to record the changes of vertical overlap and the comfort level of patients before and after the selective grinding of the three dentures made according to maxillo-mandibular horizontal relationship record.@*METHODS@#Twelve edentulous patients with normal stomatognathic system were recruited in this study. Three types of complete dentures for these 12 edentulous patients were made according to their different maxilla-mandibular horizontal relationship record methods. The amount of displacement of the maxillary complete denture, the vertical overlap of the anterior teeth as well as patient comfort level were recorded before and after selective grinding. Statistical analysis was performed using the SPSS 17.0 software package.@*RESULTS@#Before selective grinding, the amount of displacement of denture A was significantly larger than those of dentures B and C (P0.05). During selective grinding, the vertical overlap variation of denture A was significantly greater than those of dentures B and C (P0.05). After selective grinding, no statistical difference was found among the three dentures (P>0.05).@*CONCLUSIONS@#Among the complete dentures with anatomical teeth, the dentures whose horizontal relationship was recorded at 1 mm before the apex of the Gothic arch apex and with checkbite are more in line with clinical repair requirements. Complete dentures whose horizontal relationship was recorded at the apex of Gothic arch need to be adjusted with selective grinding to meet the clinical restoration requirements.

Application of single-retainer all-ceramic resin-bonded fixed partial denture in the maintenance of missing incisor gap after orthodontic treatment in adolescents: a case report / 华西口腔医学杂志

This article reports a case of an orthodontic adolescent patient without a right inferior incisor. The right lower canine was used as the abutment. The single-retainer all-ceramic resin-bonded fixed partial denture was used to restore the complete dentition. Thus, the missing space was filled, and the function and aesthetics were restored.

Nomograma prediction of the surgical treatment in triad of elbow / 中国骨伤

OBJECTIVE@#To establish an individualized Nomogram prediction model for predicting the postoperative recovery of patients with triad of elbow (TE) by analyzing risk factors of triad of elbow joint.@*METHODS@#From January 2012 to December 2018, 116 patients with TE who met the criteria were collected. The independent risk factors were screened by univariate Logistic regression analysis. The statistically significant risk factors were included in the multivariate Logistic regression model. The R software was used to establish the Nomogram diagram model to predict the postoperative recovery of TE patients. C index was used to verify the discrimination, Calibration plot of the model, and the decision curve (decision curve analysis, DCA) to verify the net clinical benefit rate of the model.@*RESULTS@#Forty-four of the 116 patients with TE developed symptoms after operation, with an incidence of 37.93%. Age (@*CONCLUSION@#The Nomogram for predicting postoperative results of TE patients based on six independent risk factors:age, work, smoking, Mason classification of radial head, Regan-Morrey classification of coronal process and immobilization time of elbow joint after operation, has good distinguishing capacity and consistency. Thepredictive model could help clinicians to identify high risk population and establish appropriate intervention strategies.

Case control study of unilateral and bilateral intervertebral space release in the treatment of lower lumbar spondylolisthesis / 中国骨伤

OBJECTIVE@#To analyze the clinical efficacy of unilateral and bilateral intervertebral space release in the treatment of lower lumbar spondylolisthesis.@*METHODS@#The clinical data of 41 patients with lumbar spondylolisthesis treated by surgery from October 2012 and May 2016 were retrospcetive analyzed. The patients were divided into two groups, 18 cases were enrolled in unilateral intervertebral release group, there were 7 males and 11 females, aged from 47 to 75 years old with an average of (59.3±6.4) years; according to Meyerding classification, 9 cases of I degree, 7 cases of II degree, 2 cases of III degree. And 23 cases were bilateral release group, there were 11 males and 12 females, aged from 51 to 76 years old with an average of (58.2±5.7) years; according to Meyerding classification, 11 cases of I degree, 10 cases of II degree, 2 cases of III degree. The operation time, intraoperative blood loss, bone graft fusion rate of the patients were recorded in the patients. Pre- and post-operative back and leg pain were evaluated by visual analogue scale (VAS) between two groups. The slip rate, slip angle, posterior height of intervertebral space, height of intervertebral foramen, distance of anterior and posterior displacement of vertex of intervertebral foramen were measured on X-ray and CT. And the above radiographic data were analyzed by intra-group or inter-group.@*RESULTS@#All the patients were followed up from 9 to 24 months with an average of 12 months. The entire 41 patient obtained bone fusion at 12 months after operation. There was no statistical significance in VAS at 12 months after operation, intraoperative blood loss and operation time between two groups(>0.05). There were statistical significance in sliding angle, posterior height of intervertebral space, height of intervertebral foramen, distance of anterior and posterior displacement of vertex of intervertebral foramen of all patients before and after operation(0.05), but there was significant difference in bilateral release group. There was statistical significance in postoperative slip angle, posterior height of intervertebral space, distance of anterior and posterior displacement of vertex of intervertebral foramen between two groups(=0.001, 0.045, 0.001). The height of intervertebral foramen increased and the slippage rate decreased in both groups after operation, but there was no significant difference between two groups(=0.248).@*CONCLUSIONS@#Unilateral and bilateral intervertebral space release for the treatment of lumbar spondylolisthesis can obviously reduce the rate of spondylolisthesis, restore foraminal height and achieve better clinical efficacy. Bilateral release group can better restore the slip angle, increase posterior height of intervertebral space, reduce the distance of anterior and posterior displacement of vertex of intervertebral foramen. Especially for grade II or above degree of slippage is more appropriate.

Clinical outcome analysis on using extensor digitorum communis splitting approach for the treatment of radial head fractures / 中国骨伤

<p><b>OBJECTIVE</b>To explore the clinical outcomes of internal fixation or replacement for the treatment of radial head fractures through the extensor digitorum communis splitting approach.</p><p><b>METHODS</b>From July 2012 to May 2015, 25 patients with radial head fractures were reviewed. There were 17 males and 8 females, ranging in age from 20 to 67 years old, with a mean age of 39 years old. Twenty-one patients were treated with reconstruction of plate internal fixation, and 4 patients were treated with radial head replacement. According to Mason classification, 19 cases were type II and 6 cases were type III. All the patients underwent internal fixation or replacement through the extensor digitorum communis splitting approach. The patients were followed up clinically and radiographically until the beginning of fracture union and the entrance of function recovery of elbow motion into a plateau. The functional status of the elbow was evaluated using the Mayo Elbow Performance Index(MEPI). Radiographic signs of post-traumatic arthritis were rated according to the Broberg and Morrey system.</p><p><b>RESULTS</b>All the patients were followed up, and the average duration was 29 months (ranged, 12 to 56 months). The average range of flexion and extension was 120°, the extension was limited by 10°, and the flexion was 135°. The average forearm rotation range was 142°, pronation was 75°, supination was 67°. The mean MEPI was 93±7(ranged, 80 to 100 scores); according to the MEPI scoring criceria, 19 patients got an excellent functional result, 6 good. According to the Broberg and Morrey systems of traumatic arthritis, 19 patients were in grade 0, 6 in grade 1, and no patients in grade 2 or 3. No patients with nonunion of the radial head and failure of internal fixation were found. There were no complications of nerve or vascular injuries, and obvious limitation of elbow rotation. Heterotopic ossification around the elbow occurred in 4 cases, but the motion was not significantly limited. There were no complications such as prosthesis loosening and infection in 4 cases after radial head prosthesis replacement.</p><p><b>CONCLUSIONS</b>The extensor digitorum communis splitting approach is an effective exposure method for internal fixation or replacement in the treatment of radial head fractures.</p>

Progress on atlanto-axial pedicle screw fixation through posterior approach / 中国骨伤

The present of atlanto-axial pedicle screw fixation through posterior approach provide a new remedy for treating instability of pillow and cervical. A lot of researches have reported feasibility of atlanto-axial pedicle screw fixation, the results showed that it had advantages of easily exposure, less blood loss, shorter operative time, especially in treating as remedy fixation for atlanto-axial joint screw, atlas lateral mass screws and pedicle screw caused by injuries of tumor,inflammation and trauma. If not done properly, it can cause serious complications, such as iatrogenic fracture,injuries of vertebral artery and cervical spinal cord. Therefore,the safty and effectiveness of atlanto-axial pedicle screw fixation may be focus of research.

Transoral plate internal fixation for treatment of instability atlas fracture / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the efficacy and safety of transoral plate internal fixation for instability atlas fracture.</p><p><b>METHODS</b>A retrospective study was performed in eight patients with instability atlas fractures, who were treated by a transoral plate internal fixation from July 2007 to June 2011. There were 6 males and 2 females,with an average age of 39.5 years old ranging from 23 to 48 years. Among them, 5 case were falling injury, 3 cases were traffic accident injury. Three patients had bilateral fractures of the anterior arch (prehalf Jefferson fractures, Landells type I), 5 had anterior are fracture associated posterior are fracture (Half-ring Jefferson fractures, Landells type II), and 2 had anterior and posterior are fracture associated with single lateral mass fractures (Landells type III).</p><p><b>RESULTS</b>All patients were followed up for 6 to 24 months after operation (av- eraged 13 months), and all the patients had the clinical symptoms improved to some extent. Operation time ranged from 80 to 140 min (averaged 98 min); the intra-operative blood loss was 120 to 300 ml (averaged 180 ml); and the average fluoroscopic time was 55 s. No patients happened neurological and vertebral artery injuries-related complications or other complications after operation. The followed-up X-ray and CT manifested osseous fusion in all the 8 patients,no loosening or breakage of the screws.</p><p><b>CONCLUSION</b>Transoral plate internal fixation for instability atlas fracture is a reliable and safety technique that allows maintenance of rotatory mobility in the C1,2 joint and restoration of congruency in the atlanto-occipital and atlanto-axial joints.</p>

Posterior osteotomy and long-segment internal fixation for the treatment of senile thoracolumbar kyphotic deformity / 中国骨伤

<p><b>OBJECTIVE</b>To explore the therapeutic effects of posterior osteotomy and long-segment internal fixation in the treatment of senile thoracolumbar kyphotic deformity and provide the reference for operative treatment.</p><p><b>METHODS</b>From April 2007 to April 2010, 19 older patients with thoracolumbar kyphotic deformity were respectively analyzed. There were 12 males and 7 females with an average age of 62 years (ranged, 58 to 74 years). Among patients, 11 cases were old fracture, 3 cases were ankylosing spondylitis, and 5 cases were old spinal tuberculosis. According to preoperative Frankel classification, 12 cases were grade E, 4 cases were grade D, 2 cases were C and 1 case was grade B. All patients were treated by posterior osteotomy and long-segment internal fixation and followed up above 1 year. VAS score preoperative, 2 weeks and 1 year after operation, Cobb's angle,n erve function and complication were observed.</p><p><b>RESULTS</b>VAS score preoperative, 2 weeks and 1 year after operation separately was (7.0 +/- 1.2),(1.1 +/= .7) and (1.3 +/- .8); while Cobb's angle separately was (44.1 +/- .9), (10.9 +/- .1) and (11.5 +/- .8); there was significant difference in VAS score and Cobb's angle between preoperative and 2 weeks after operation (P < 0.05) w hile no significant difference between 2 weeks and 1 year after operation (P > 0.05). Eighteen cases met the standard of osseous fusion, 1 case occurred nonunion, but not looseness 1 year after operation. Nerve function: 3 cases changed grade E from 4 cases with grade D, 2 cases with grade C changed to grade D, 1 case with grade B changed to grade</p><p><b>CONCLUSION</b>Posterior osteotomy and long-segment internal fixation for the treatment of senile thoracolumbar kyphotic deformity can receive a good short-time effects.</p>

Anatomic study of lower cervical spinous process for laminar screw fixation / 中国骨伤

<p><b>OBJECTIVE</b>To measure anatomic data of spinous process and vertebral plate and evaluate the possibility of fixation of spinous process and vertebral plate.</p><p><b>METHODS</b>Twenty cadaveric cervibal spines of C3-C7 were dissected to expose vertebral plate and spinous process, and were measured by two methods, one was manual measured using digital caliper and the other was computed tomography scaning. Parameters were measured manually including vertebral plate height and width. The screw was inserted from the boundary of the vertebral plate and spinous process, and gone out from the top of vertebral plate back of opposite side. Then through the CT reconstruction, angle of screw insertion, length of screw trajectory and distance between the screw tip and vertebral artery and spinal cord were measured. Additionally, spinous process width and vertebral plate thickness of 100 patients' CT scans of C3-C7 cervical segment were measured to evaluate possibility of screw insertion at spinous process and vertebral plate.</p><p><b>RESULTS</b>The screw fixation of lower cervical spinous process and vertebral plate were successfully placed,without impingement of spinal cord and vertebral artery. There was no statistic difference on the data of lamina height and width of 20 cadaver specimens between manual and CT measurements (P>0.05). Height and width of vertebral plate was (12.4 +/- 1.2) to (13.7 +/- 1.3) mm and (4.5 +/- 0.9) to (5.4 +/- 1.1) mm respectively and increased gradually from C3 to C7 (P<0.05). The trajectory length was (13.7 +/- 1.2) to (15.8 +/- 1.8) mm and increased gradually from C3 to C7 (P<0.05). The distance between screw tip and vertebral artery and spinal cord was (20.1 +/- 2.7) to (25.8 +/- 2.9) mm and (4.1 +/- 1.8) to (5.0 +/- 1.2) mm respectively. The angles of screws insertion were (73.0 +/- 9.9) degrees to (85.3 +/- 10.1) degrees in the axial plane (P>0.05). Based on the CT measurements of 100 patients,the data of the spinous process width and lamina thickness varied from a minimum of (8.5 +/- 1.1) mm and (4.3 +/- 0.5) mm for the C4, to a maximum of (14.5 +/- 2.0) mm and (6.0 +/- 1.1) mm for the C7 respectively.</p><p><b>CONCLUSION</b>Lower cervical spinous process and vertebral plate screw fixation is feasible, which is a safe and stable screw approach for spinous process and vertebral plate fixation.</p>

Clinical application of lower cervical spinous process laminar screw technique in open door laminoplasty / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the clinical outcomes of lower cervical spinous process laminar screw technique in open door laminoplasty.</p><p><b>METHODS</b>From February 2005 to June 2010,12 patients with cervical myelopathy were treated with open door laminoplasty by lower cervical spinous process laminar screw technique. There was intervertebral disc herniation with degenerative stenosis in 5 patients, ossification of posterior longitudinal ligament with osteophyte in 6 patients, cervical traumatic instability with spinal cord injuries in 1 patient. Nerve function, complications, and the cervical canal to body ratio (CBR), range of motion (ROM) and the anteroposterior serial alignment were observed by Japanese Orthopedic Association (JOA) score, X-ray, CT and MRI.</p><p><b>RESULTS</b>The surgical time was from 1.5 to 2 h with an average of 110 min; blood loss during operation was from 450 to 800 ml with an average of 580 ml. Postoperative complication occurred in 1 case with upper limb pain and 1 case with cerebrospinal fluid leakage. All patients were followed up from 1 to 2 years with an average of 21.8 months. JOA score improved from preoperative 9.5 +/- 1.8 to postoperative 13.6 +/- 2.4 (P < 0.01). X-ray, CT, MRI showed CBR increased obviously (P < 0.01); ROM on flexion-extension and cervical lordosis decreased respectively from (40.0 +/- 10.0) degrees and (65.0 +/- 12.0)% before operation to (15.0 +/- 5.0) degrees and (42.0 +/- 8.0) % at the final follow-up (P < 0.01).</p><p><b>CONCLUSION</b>Lower cervical spinous process laminar screw technique in open door laminoplasty for cervical syndrome is safe and can obtain satisfactory effects, has strong internal fixation and reduce the risk of re-closure.</p>

Study on the feasibility of posterior thoracic transarticular screw fixation / 中国骨伤

<p><b>OBJECTIVE</b>To study the feasibility and technical parameters of posterior transarticular screw fixation in the thoracic spine.</p><p><b>METHODS</b>Since September 2009 to December 2009, 20 thoracic cadaveric spines (12 males and 8 females) were dissected. The lateral masses and pedicles were exposed carefully. After the entrance point of transarticular screws was determined, posterior transarticular screws implantation was performed under direct visualization into T(1,2), T(5,6) and T(9,10). Then CT scan was performed. On the CT scan,the angle and length of the transarticular screw trajectory were measured.</p><p><b>RESULTS</b>The thoracic transarticular screw trajectory were caudal tilting in the sagittal plane and lateral tilting in the coronal plane with successful placement. There was little differences between different segmental of thoracic vertebrae of the angle, but without significance (P > 0.5). The average angles of the screws were (52.6 +/- 5.9) degrees caudal tilting in the sagittal plane and (12.4 +/- 2.9)0 lateral tilting in the coronal plane. The average trajectory lengths were (22.5 +/- 1.9) mm. There was significant differences statistically among T(1,2), T(5,6) and T(9,10) (P < 0.01).</p><p><b>CONCLUSION</b>Posterior transarticular screw fixation is feasible. Transarticular screw fixation in the thoracic spine affords an alternative to standard pedicle screw placement for thoracic stabilization.</p>

Biomechanical study on the posterior screw fixation in the lower cervical spine / 中国骨伤

So far, the fixation in the lower cervical spine through posterior approach technology has commonly been used, besides the lateral screw and pedicle screw techniques, transarticular screw and laminar screw techniques have being paid more attention recently. This article introduced four screw fixation ways in the lower cervical spine through posterior approach and reviewed the recent biomechanics studies of four screw fixation techniques. The biomechanics study includes stabilization, pollout strength, insertion technique, and screw characteristic and so on. Lateral screw and pedicle screw techniques have become an effective internal fixation way for the lower cervical spine instability because of their superior stabilization and higher pollout strength. Transarticular screw fixation has become a new way to fix the lower cervical spine through posterior approach, which has widely surgical indications. Besides, this technique is relatively safe, simple and has achieved favorable curative effect in clinic. Laminar screw fixation technique is rarely used in clinic, but the study of anatomy and biomechanics confirmed that this technique can be applied as a salvage technique in clinic. Above four techniques of the screw fixation in the lower cervical spine through posterior approach have advantages and disadvantages, respectively, and the application in clinic is different. Through the biomechanics study of these techniques will contribute to the development of the techniques of the screw fixation in the lower cervical spine through posterior approach and guide the clinical work effectively.

Anatomic comparison between spinous process screws and pedicle screws techniques of the second cervical vertebar / 中国骨伤

<p><b>OBJECTIVE</b>To compare anatomic difference between spinous process screws and pedicle screws techniques of the second cervical vertebra.</p><p><b>METHODS</b>Ten human cadaveric of cervical spine (5 male, 5 female) were harvested and had no gross deformities such as scoliosis and/or kyphosis were found in the study. The average age of the subjects was 60.5 years. The specimens were placed in the prone position. Posterior cervical exposure was attained by dissecting all soft tissue off the posterior aspect of the second cervical vertebra. After clear exposure of the lateral mass,the spinous process screw and pedicle screw insertion techniques were performed in this study. Each technique involved ten specimens and 10 screws inserted into C2 bilaterally. The one side of C2 was randomly selected for the spinous process screw and the other side was designate for the pedicle screw. This point then was drilled with a 3 mm drill, and followed by placement of a 4.0 mm cortical screw. The starting point for spinous process screw insertion was located at the junction of the lamina and the spinous process and the direction of the screw was about 0 degrees caudally in the sagittal plane and about O0 medially in the axial plane. The starting point of pedicle screw should be the midpoint of the base of inferior articular facet of the axis. The drilling angle was 15 degrees to 20 degrees in the superior direction and 30 degrees in the medial direction. After screw placement, all the specimens were CT scaned. On the CT scan,the length of the spinous process screw and pedicle screw trajectory were measured. Results were recorded for each screw that violated impinged of the pedicle, spinal canal and transverse process foramen.</p><p><b>RESULTS</b>All the C2 spinous process screws were successfully placed, without impingement the spinal cord, the vertebral artery and the breakage of the spinous process. There was one pedicle screw breaking the pedicle into the vertebral artery foramen. The trajectory length for the spinous process screws were (21.4 +/- 1.4) mm,compared with the pedicle screws (23.7 +/- 1.0) mm. But there was no significant differences between spinous process screws and pedicle screws techniques (t = -4.387, P > 0.05).</p><p><b>CONCLUSION</b>The C2 spinous process screw fixation has the anatomic feasibility and is easier to perform than pedicle screw fixation.</p>

An anatomic study of posterior C(2) spinous process laminar screw fixation / 中华外科杂志

<p><b>OBJECTIVES</b>To explore the feasibility and the technical parameters in posterior C2 spinous process laminar screw fixation, and discuss the clinic significance of C2 spinous process laminar screws.</p><p><b>METHODS</b>Twenty cervical cadaveric spines of C2 were dissected, with care taken to expose the lamina and spinous process. After the entrance point of spinous process screw were determined, posterior C2 spinous process laminar screw implantation was performed under visual control. On the morphologic CT scan, the angle and length of the spinous process laminar screw trajectory and the distance between the tip of the screw and the spinal cord and the vertebral artery were measured.</p><p><b>RESULTS</b>The C2 spinous process laminar screws were successfully placed, without impingement of the spinal cord and the vertebral artery. There were little differences between superior and inferior screws in the angle, trajectory length and the distance between the tip of the screw and the spinal cord and the vertebral artery, but without significance (P > 0.05). The placed angles of the screws were 76.8° ± 10.6° in the axial plane. The distance between the tip of the screw and the spinal cord and the vertebral artery was (5.3 ± 1.6) mm and (17.4 ± 3.7) mm respectively. The trajectory length was (23.1 ± 3.2) mm.</p><p><b>CONCLUSIONS</b>Posterior C2 spinous process laminar screw fixation is feasible. C2 spinous process laminar screw fixation affords an alternative to standard screw placement for plate fixation and cervical stabilization.</p>

Operative treatment of old acetabular fractures / 中国骨伤

<p><b>OBJECTIVE</b>To explore the operative methods and effects of treatment of old acetabular fractures.</p><p><b>METHODS</b>From October 2001 to October 2007, 26 patients with old acetabular fractures were treated with operation including 21 males and 5 females with an average age of 34 years ranging from 18 to 65 years. On the basis of the three-dimensional computed tomography, all cases were diagnosed and classified according to Letourne-Judet classification, 9 cases were posterior wall fracture, 3 cases were lateropulsition fracture, 7 cases were lateropulsition and posterior wall fracture, 2 cases were posterior column and posterior wall fracture, 2 were T-shape fracture, 3 were dual column fracture. These patients were treated through the anterior,posterior, combined anterior-posterior approaches. The time from injured to operation was 33 to 141 days (averaged 36.4 days). All the fractures were fixed with screws and AO reconstruction plates.</p><p><b>RESULTS</b>All patients were followed up for 6 to 96 months, with an average time of 32.4 months. Evaluated according to Matta criteria, the results of scores was (5.04 +/- 1.04) on pain, (5.23 +/- 0.76) on range of motion, (4.92 +/- 1.16) on walking,and tatal (5.06 +/- 0.99) on average; The functional results of hip joints were excellent in 6 cases, good in 10 cases, fair in 6 cases, and poor in 4 cases. Sciatic nerve injury was found in 2 patients,lateral femoral cutaneus nerve injury in 3 patients, necrosis of femoral head in 1 patient,infection in 1 patient, and ectopic bone formation in 6 patients.</p><p><b>CONCLUSION</b>Good clinical results can be obtained by careful selection of operative indications of old acetabular fractures in combination with proper operative approach and correct reduction and fixation.</p>

Biomechanical study on transarticular screw and plate fixation syetem in the lower cervical spine / 中国骨伤

<p><b>OBJECTIVE</b>To compare the cervical stabilities of transarticular screw fixation alone, and transarticular screw and plate fixation system.</p><p><b>METHODS</b>Twelve specimens of cervical vertebra containing C2-T1 were obtained from human cadaver. The three-column instability model was made at C4.5 and C5.6 levels. The specimens were stabilized with transarticular screw fixation alone, and transarticular screw and plate fixation system respectively. The ranges of motion of segments including intact group, transarticular screw fixation alone group and transarticular screw and plate fixation system group were measured under the torque of 2.0 N x m in flexion, extension, lateral bending, and torsion respectively under nonrestrictive and nondestructive condition.</p><p><b>RESULTS</b>The rang of motion (ROM) and neutral zone (NZ) of both transarticular screw fixation alone and transarticular screw and plate fixation system group were significantly smaller than those of intact group in all directions (P < 0.05). The transarticular screw and plate fixation system group allowed a very smaller ROM and NZ than transarticular screw fixation alone during extension, lateral bending and axial rotation except flexion (P < 0.05).</p><p><b>CONCLUSION</b>Cervical transarticular screw and plate fixation system provides better stability than transarticular screw fixation alone. If the transarticular fixation technique is preferred, transarticular screw and plate fixation system will be beneficial.</p>

Anatomical considerations for the placement of C₂ spinous process screws / 中华外科杂志

<p><b>OBJECTIVES</b>To quantitatively anatomically evaluate the C₂ spinous process, analyze the anatomical feasibility of the C₂ spinous process screws and its clinical significance.</p><p><b>METHODS</b>To dissect and evaluate 30 cervical cadaveric spines of C₂ which were taken to expose the lamina and spinous process. Anatomic quantitative evaluation of the C₂ spinous process included its height and width. Twenty cervical cadaveric spines of C₂ were chosen to the study of the placement of the C₂ spinous process screws. The starting point for the C₂ spinous process screw insertion was located at the base of the spinous process. After the entrance point of spinous process screws was determined, posterior C₂ spinous process screw implantation was performed bilaterally under direct visualization. On the morphologic CT scan, the width of C₂ spinous process base, the angle and length of the spinous process screw trajectory, and the distance between the tip of the screw and the spinal cord and the vertebral artery were measured.</p><p><b>RESULTS</b>The average height and width of the C₂ spinous process were (12.90 ± 1.30) mm and (18.86 ± 1.17) mm respectively. The C₂ spinous process screws were successfully placed without impingement the spinal cord or the vertebral artery and the breakage of the spinous process. On the CT scan, the average width of the base of C₂ spinous process was (20.7 ± 1.3) mm. The placed angles of the screws were 1.8° ± 1.0° in the axial plane. The distance between the tip of the screw and the spinal cord or the vertebral artery was (8.3 ± 2.6) mm and (20.2 ± 3.1) mm respectively. There were little differences between superior and inferior screws in the angle, the distance between the tip of the screw and the spinal cord or the vertebral artery, but without significance (P > 0.05). The average trajectory length of the C₂ spinous process screws was (19.7 ± 1.1) mm. The average trajectory length of the superior spinous process screws was shorter than that of inferior spinous process screws, with great differences (t = 3.566, P < 0.01).</p><p><b>CONCLUSIONS</b>There is the anatomic feasibility of the C₂ spinous process screw fixation which may afford an alternative to standard screw placement for axis fixation. The biomechanical study for the C₂ spinous process screw is also necessary.</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>

Biomechanical comparison of cervical transfacet pedicle screws versus pedicle screws / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Transfacet pedicle screws provide another alternative for standard pedicle screw placement for plate fixation in the lumbar spine. However, few studies looking at transfacet pedicle screw fixation in the cervical spine are available. Therefore, cervical transfacet pedicle screw fixation and standard pedicle screw fixation techniques were biomechanically compared in this study.</p><p><b>METHODS</b>Ten fresh human cadaveric cervical spines were harvested. On one side, transfacet pedicle screws were placed at the C3-4, C5-6, and C7-T1 levels. On the other side, pedicle screws were placed at the C3, C5, and C7 levels. The screw insertion technique at each level was randomized for right or left. The starting point for the transfacet pedicle screw insertion was located at the midpoint of the inferolateral quadrant of the lateral mass and the direction of the screw was about 50 degrees caudally in the sagittal plane and about 45 degrees toward the midline in the axial plane. Screws were placed from the inferior articular process, across the facet complex and the pedicle into the body of the caudal vertebra. The entry point for the pedicle screw was located at the midpoint of the superolateral quadrant of the lateral mass, and the direction of the screw was about 45 degrees toward the midline in the axial plane and toward the upper third of the vertebral body in the sagittal plane. After screw placement we performed axial pullout testing.</p><p><b>RESULTS</b>All the cervical transfacet pedicle screws and the pedicle screws were inserted successfully. The mean pullout strength for the transfacet pedicle screws was 694 N, while for the pedicle screws 670 N (P=0.013). In all but six instances (10%), the pedicle screw pullout values exceeded the values for the transfacet pedicle screws; this occurred three times at the C3/C4 level, twice at the C5/C6 level and once at the C7/T1 level. The greatest pullout strength difference at a single level was observed at the C5/C6 level, with a mean difference of 38 N (t=-1.557, P=0.154). The C7/T1 level had a mean difference of 26 N and the C3/C4 level had a mean difference of 14 N.</p><p><b>CONCLUSIONS</b>Cervical transfacet pedicle screws exhibited higher pullout strength than pedicle screws. Posterior transfacet pedicle screw fixation in the cervical spine may afford an alternative to standard screw placement for plate fixation and cervical stabilization.</p>