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ABSTRACT: STUDY DESIGN:: A retrospective case series describing teardrop fracture of the axis. OBJECT:: The purpose of the study was to clarify the clinical features, the mechanism of injury and the potential instability of extension teardrop fractures of the axis, so as to emphasize the importance of recognizing this injury as a separate entity. SUMMARY OF BACKGROUND DATA:: Teardrop fractures of the axis are rare spinal fractures, comprising only a small percentage of all injuries of the cervical spine. The stability of this fracture pattern has been a matter of debate leading to controversy regarding treatment strategies and the need for stabilization. METHODS:: We retrospectively reviewed data from 16 patients to document mechanism of injury, neurological deficit, treatment and clinical outcome, and imaging findings. RESULTS:: Extension teardrop fractures accounted for approximately 8.9% of upper cervical spinal injuries and 12.7% of axis fractures at the authors' institution over the same period. Six patients (4 males and 2 females) underwent surgery (4 via an anterior approach, 2 cases via a posterior approach). Ten cases underwent Halo-vest immobilization for a period between 6 and 12 weeks. At final follow-up, fourteen cases achieved excellent results, while two patients complained of mild residual neck pain. Maximum cranial-caudal dimensions of the fragments were between 5 and 24 mm (average, 12.9 mm), and the transverse dimensions were between 5 and 22 mm (average, 11.1 mm). Fragment displacement ranged from 1 to 9 mm (average, 3.5 mm) while fragment rotation ranged from 10 to 52 degrees (average, 24.4 deg) in the sagittal plane. CONCLUSIONS:: Most patients with an extension teardrop fracture of the axis can be treated conservatively. Based on this case series, the authors suggest that large fragment size, displacement or angulation, intervertebral disc injury, neurologic deficit or signs of instability are reasonable indications for surgical treatment.
Journal of spinal disorders & techniques 02/2013; · 1.21 Impact Factor
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ABSTRACT: Object The aims of this study were to evaluate a large series of posterior C-1 lateral mass screws (LMSs) to determine accuracy based on CT scanning findings and to assess the perioperative complication rate related to errant screw placement. Methods Accuracy of screw placement was evaluated using postoperative CT scans obtained in 196 patients with atlantoaxial instability. Radiographic analysis included measurement of preoperative and postoperative CT scans to evaluate relevant anatomy and classify accuracy of instrumentation placement. Screws were graded using the following definitions: Type I, screw threads completely within the bone (ideal); Type II, less than half the diameter of the screw violates the surrounding cortex (safe); and Type III, clear violation of transverse foramen or spinal canal (unacceptable). Results A total of 390 C-1 LMSs were placed, but 32 screws (8.2%) were excluded from accuracy measurements because of a lack of postoperative CT scans; patients in these cases were still included in the assessment of potential clinical complications based on clinical records. Of the 358 evaluable screws with postoperative CT scanning, 85.5% of screws (Type I) were rated as being in the ideal position, 11.7% of screws (Type II) were rated as occupying a safe position, and 10 screws (2.8%) were unacceptable (Type III). Overall, 97.2% of screws were rated Type I or II. Of the 10 screws that were unacceptable on postoperative CT scans, there were no known associated neurological or vertebral artery (VA) injuries. Seven unacceptable screws erred medially into the spinal canal, and 2 patients underwent revision surgery for medial screws. In 2 patients, unilateral C-1 LMSs penetrated the C-1 anterior cortex by approximately 4 mm. Neither patient with anterior C-1 penetration had evidence of internal carotid artery or hypoglossal nerve injury. Computed tomography scanning showed partial entry of C-1 LMSs into the VA foramen of C-1 in 10 cases; no occlusion, associated aneurysm, or fistula of the VA was found. Two patients complained of postoperative occipital neuralgia. This was transient in one patient and resolved by 2 months after surgery. The second patient developed persistent neuralgia, which remained 2 years after surgery, necessitating referral to the pain service. Conclusions The technique for freehand C-1 LMS fixation appears to be safe and effective without intraoperative fluoroscopy guidance. Preoperative planning and determination of the ideal screw insertion point, the ideal trajectory, and screw length are the most important considerations. In addition, fewer malpositioned screws were inserted as the study progressed, suggesting a learning curve to the technique.
Journal of neurosurgery. Spine 02/2013; · 1.61 Impact Factor
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ABSTRACT: To explore the best entry point and trajectory of anterior cervical screw in the cervical screw by radiological studies, and provide reference for clincal application.
From January 2008 to December 2010,50 patients were scanned by cervical CT and confirmed no obvious defect of lower cervical spine. Of them, 27 cases were males and 23 were females, ranged the age from 38 to 83 years ( mean 58.5 years). On horizontal axis, the camber angle of C3-C7 anterior lower cervical pedicle of vertebral arch axis (alpha) and distance between (axial length, AL) of anterior cervical pedicle axial line was measured from C3 to C7. Vertebral were divided into four areas, and from measured side of pedicle of vertebral began to record, orderly 1 to 4, the area of pedicle vertebral arch intersert into vertebral were recorded. On sagittal view, the head or tail angle (beta) and length (sagittal length, SL) of anterior cervical pedicle axial line was also measured from C3 to C7. Vertebral were divided into four areas, and from measured side of pedicle of vertebral began to record, orderly 1 to 4, the area of pedicle vertebral arch arch intersert into vertebral were recorded. The above data were statistically analyzed to find the best entry point and trajectory of anterior cervical screw in the cervical screw and insert pedicle screw.
The lateral angle of lower cervical spine was 38 degrees to 45 degrees on transverse plane, C3 to C5 increasing gradually, C5 to C7 decreasing. On sagittal view, C3,C4 pedicle were head tulting, C5 were basic level, C6,C7 were tail. C3 to C5 decreasing gradually, C5 to C7 increasing gradually. C3 to C7 in AL and SL increased gradually. On horizontal axis, the intersection of C3,C4 and C5 were in the second area, the number of C6 in the second and third area were the same, but C7 were in the third area. The intersection in the first and forth area were less. On sagittal view,the intersection of C3,C4 and C5 were in the first area,the number of C6 in third and forth area were less. Six pedicle screws of 3 cases were insert into lower cervical spine, and obtained good effects, no complications occurred.
The best entry point of C3,C4 and C5 were located in the center line and slightly to opposite vertebral body side and upper 1/4 area; C7 were located the vertebral body side and upper 2/4 area; C6 were located between them. The best insertion point were extraversion 38 degrees to 45 degrees, C3 to C5 increased graduallly, C5 to C7 decreased on horizontal axis; On sagittal view, C3,C4 for head 5 degrees to 10 degrees, C5 were basic level, C6,C7 for tail 5 degrees to 10 degrees. The anterior cervical pedicle screw for lower cervial spine is a good and feasible internal fixation.
Zhongguo gu shang = China journal of orthopaedics and traumatology 12/2012; 25(12):1030-5.
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ABSTRACT: To explore the clinical application of Centerpiece titanium plate fixation in open door laminoplasty.
From January 2009 to December 2010,25 patients with cervical spinal stenosis were treated by open door laminoplasty with Centerpiece titanium plate fixation. There were 16 males and 9 females,with a mean age of (57.2 +/- 6.7) years (ranged, 44 to75 years). There were multilevel cervical myelopathy in 8 cases, posterior longitudinal ligament ossification in 12 cases and congenital cervical spinal stenosis in 5 cases. According to Japanese Orthopedic Association (JOA) score to evaluate nerve function and calculate improvement rate. X-ray and CT were used to evaluate postoperative spinal canal enlargement and bone fusion at the hinge side. The sagittal diameter of C5 spinal canal on the lateral X-ray was measured before operation and 6 months after operation respectively, and the expansion rate of spinal canal was calculated [(postoperative sagittal diameter-preoperative sagittal diameter)/(preoperative sagittal diameter) x 100%].
The operative time and intraoperative blood loss were respectively (165.5 +/- 35.6) min and (325.0 +/- 75.1) ml. All patients were followed up from 6 to 18 months with an average of (7.3 +/- 3.8) months. The JOA score increased from 9.3 +/- 1.1 before operation to 14.7 +/- 2.1 at 6 months after operation (t = 4.12, P < 0.05), and the improvement rate was (64.5 +/- 10.2)%. Radiographic data showed spinal canal enlarged perfectly, bone fusion at hinge side and no cervical spinal stenosis was found. The sagittal diameter of C5 spinal canal improved from (9.0 +/- 1.5) mm before operation to (14.3 +/- 2.0) mm at 6 months after operation (t = 7.61, P < 0.05), and the expansion rate was (67.6 +/- 11.8)%.
Clinical application of Centerpiece titanium plate fixation in open door laminoplasty is safe and effective. While vertebral plate is elevated to obtain instantly stability, at the same time, the integrity of spinal canal is also recovered.
Zhongguo gu shang = China journal of orthopaedics and traumatology 09/2012; 25(9):726-9.
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ABSTRACT: To investigate the clinical outcomes of lower cervical spinous process laminar screw technique in open door laminoplasty.
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.
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).
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.
Zhongguo gu shang = China journal of orthopaedics and traumatology 09/2012; 25(9):711-4.
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ABSTRACT: To measure anatomic data of spinous process and vertebral plate and evaluate the possibility of fixation of spinous process and vertebral plate.
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.
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.
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.
Zhongguo gu shang = China journal of orthopaedics and traumatology 07/2012; 25(7):594-8.
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ABSTRACT: 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.
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.
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
Posterior osteotomy and long-segment internal fixation for the treatment of senile thoracolumbar kyphotic deformity can receive a good short-time effects.
Zhongguo gu shang = China journal of orthopaedics and traumatology 04/2012; 25(4):299-302.
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ABSTRACT: Biomechanics plays an important role in the pathogenesis of upper cervical spine disease. Traditional biomechanical test, such as animal experiment, physical experiment and vitro experiment exists many problems. Finite element method, a new biomechanical method, can repeat in sustainability study, change quality and quantity, provide the manifestation of local and internal region and make up the deficiency of current methods. The paper summaries the biomechanical application of finite element method in upper cervical spine, including the finite element modeling, pathophysiological mechanism of upper cervical spine and biomechanical analysis of internal fixation devices.
Zhongguo gu shang = China journal of orthopaedics and traumatology 03/2012; 25(3):262-6.
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ABSTRACT: The occult sacral fracture has no symptoms of sacral nerves injuries and no severe pain. These occult sacral fractures have no significant fracture signs on plain X-ray film, which can be found only by spiral CT or MRI and be misdiagnosed easily. This article made a brief review on the diagnosis and treatment of this type of sacral fractures.
Zhongguo gu shang = China journal of orthopaedics and traumatology 12/2011; 24(12):1051-4.
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ABSTRACT: To explore the clinical efficacy of delayed open reduction and internal fixation with minimally invasive percutaneous locking compression plate for the treatment of type II and III Pilon fractures.
From January 2007 to September 2009, 32 patients with type II and III Pilon fractures were treated with open reduction and anatomic plate fixation (AP group) and minimally invasive percutaneous locking compression plate osteosynthesis (LCP group). There were 11 males and 6 females in AP group, with an average age of (37.4 +/- 13.3) years (ranged, 19 to 55 years). And there were 10 males and 5 females in LCP group, with an average age of (34.6 +/- 11.3) years(ranged, 21 to 56 years). The operating time, fracture healing time, aligned angulation and ankle function were compared between the two groups.
All the patients were followed up, and the during ranged from 12 to 25 months, with a mean of (15.0 +/- 1.7) months. The average operation time was (76.5 +/- 8.3) min for AP group and (58.3 +/- 3.4) min for LCP group; the average time of fracture healing was (20.5 +/- 0.4) weeks for AP group and (15.7 +/- 0.2) weeks for LCP group; the total angulation between anterior posterior film and lateral film was averaged (6.6 +/- 0.5) degrees for AP group and (3.6 +/- 0.2) degrees for LCP group. As to above index, the results of LCP group were better than those of AP group (P < 0.05). According to Kofoed criteria for ankle joint, the results of LCP group were better than those of AP group in ankle joint pain, wakling and ankle joint function (P < 0.05).
The method of minimally invasive percutaneous locking compression plate internal fixation is effective in the treatment of Pilon fracture with less invasion, faster bone union, more stabilized fixation, quicker recovery of ankle function and fewer complications, which is more advantaged for type II and III Pilon fractures.
Zhongguo gu shang = China journal of orthopaedics and traumatology 12/2011; 24(12):1010-2.
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ABSTRACT: To compare three techniques of the transarticular screw placement in the lower cervical spine.
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.
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).
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.
Zhongguo gu shang = China journal of orthopaedics and traumatology 12/2011; 24(12):1005-9.
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Zhongguo gu shang = China journal of orthopaedics and traumatology 10/2011; 24(10):848-50.
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ABSTRACT: To explore applicability and therapeutic effects of Micro-endoscopic discectomy (MED) for the treatment of lumbar disc herniation in senile patients over seventy years old.
Thirty-two patients over seventy years old with lumber disc herniation were treated by MED from December 2007 to June 2010. Among them,20 patients were male and 12 patients were female,ranging in age from 70 to 86 years, with an average of 78.5 years old. The course of diseases ranged from 2 weeks to 30 years, with an average of 3.5 years. The main clinical symptoms were low back pain with radiating pain in lower extremities, especially under the keen joint. The surgical time, blood loss, complications and function recovery were evaluated retrospectively immediately after operation. X-ray at 1 week after operation was used to observe the change of physical curvature of lumbar; MRI at 1 month after operation was used to observe the radiographic change of lumbar before and after treatment; MacNab standard was applied to evaluate the therapeutic effects at 3 months after operation.
The mean follow up period was 12.5 months (from 3 to 30 months). The mean operative time was 60 min (from 30 to 120 min) and the mean blood loss was 45 ml (from 15 to 150 ml). Leakage of cerebrospinal fluid occurred in 1 case, the operation continued after pressing by brain cotton and without nerve root and vessels injury; 1 case aggravated after revive, but other patients were eased. X-ray at 1 week after operation showed physical curvature of lumbar of 25 patients improved; MRI at 1 month after operation showed residue intervertebral disc and calcification tissue in 8 cases. Eleven patients still had numbness of limbs,but the pain and tenderness of limbs relieved. According to MacNab standard at 3 months after operation, 25 cases got an excellent result (78.1%), 6 good (18.8%) and 1 fair (3.1%).
MED is effective for the senile patients over 70 years old with lumbar disc herniation and promotes ambulation earlier. MED has the advantage of minimal invasive, less blood loss and good clinical effects; MED is suitable for the patients with obvious radiating pain in lower extremities, especially under the keen joint and combine with mild spinal stenosis and root stenosis.
Zhongguo gu shang = China journal of orthopaedics and traumatology 10/2011; 24(10):811-5.
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ABSTRACT: To investigate the clinical results of the proximal femoral nail antirotation (PFNA) system in the treatment of unstable intertrochanteric femoral fractures.
From September 2006 to September 2009, 90 patients (40 males and 50 females, ranged in age from 64 to 95 years with an average of 73.2 years with unstable intertrochanteric femoral fractures were surgically treated with PFNA. Fifty patients had the fractures in the right hip, and 40 patients had the fractures in the left hip. The fractures were classified according to the AO classification: 11 patients were type A2.1, 21 patients were type A2.2,25 patients were type A2.3 9 patients were type A3.1,6 patients were A3.2 and 18 patients were A3.3. The patients underwent surgery within a mean of 3.2 days(ranged,2 to 20.1 days) from injury. The mean hospital stay was 12.8 days(ranged,7 to 24 days). Closed reduction was achieved in all the patients. Harris hip score were used for the evaluation of clinical effects.
The mean operation time was 36.8 min (ranged, 23 to 110 min) and the mean blood loss was 150 mi (ranged, 100 to 500 ml). The mean follow-up period was 12 months (ranged, 6 to 24 months). All the patients had fracture union. Sixty-nine patients got excellent reduction, 14 good and 7 bad. The mean collodiaphysial angle was 135.60 (ranged, 1260 to 1470). Postoperative complications included secondary varus in 2 patients,calcification at the tip of the greater trochanter in 5 patients, medial thigh pain in 7 patients,and screw cut-out in 1 petient. Ten patients had femoral shortness (mean 9.3 mm,ranging from 8 to 14 mm). The mean Harris hip score was (80.5 +/- 9.8). According to Harris hip scores evaluation system, 26 patients reached an excellent result, 37 good, 18 poor and 9 bad.
Due to advantages of high union rate, short operation time, and early postoperative mobilization, PFNA osteosynthesis is an idea method for surgical treatment of unstable intertrochanteric femoral fractures.
Zhongguo gu shang = China journal of orthopaedics and traumatology 08/2011; 24(8):645-7.
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ABSTRACT: To compare anatomic difference between spinous process screws and pedicle screws techniques of the second cervical vertebra.
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.
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).
The C2 spinous process screw fixation has the anatomic feasibility and is easier to perform than pedicle screw fixation.
Zhongguo gu shang = China journal of orthopaedics and traumatology 08/2011; 24(8):659-61.
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ABSTRACT: To explore the safety and short-term efficacy of the posterior approach of the Dynesys dynamic neutralization system for degenerative disease of the lumbar vertebrae.
From March 2008 to March 2010, 32 cases of degenerative lumbar vertebral disease, 19 men and 13 women, (mean age 58 ± 5.2, range, 43-78 years), were treated with posterior laminectomy and Dynesys internal fixation. All patients had a history of over 3 months waist or leg pain that had not been relieved by conservative treatment. There were 10 cases of single lumbar intervertebral disc protrusion, 14 of degenerative lumbar spinal stenosis, 5 of degenerative lumbar isthmic spondylolisthesis, and 3 of recurrent lumbar disc protrusion after surgery. A visual analogue score (VAS) was used for pain assessment, and the Oswestry disability index (ODI) for functional evaluation of clinical outcomes.
All patients were followed up for 6-23 months (mean, 16.4 ± 5.5 months). Forty-one segments in 32 patients were stabilized; 23 cases (71.9%) underwent single-segmental stabilization, and 9 (28.1%) two-segmental stabilization. VAS of leg pain, root and low back pain was significantly improved postoperatively. The ODI improved from preoperative 69% ± 12.6% to postoperative 28% ± 15.7% (P < 0.001). On the stabilized segment and adjacent segments above and below, the range of movement showed no statistical difference; no loosening of screws, cord and polyester spacer occurred.
The Dynesys dynamic neutralization system combined with decompression can achieve satisfactory short-term clinical results in lumbar degenerative disease. This procedure system not only reduces back and leg pain, but also preserves the mobility of fixed segments, minimizes tissue injury and avoids taking bone for spinal fusion.
Orthopaedic Surgery 08/2011; 3(3):167-75.
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ABSTRACT: To introduce and evaluate a new technique, anterior pedicle screw implantation, for anterior cervical reconstruction.
Seven patients (five men and two women) with an average age of 65 years were included in this group. After carefully preparation, anterior pedicle screws were implanted under fluoroscopy in all patients. The position of the anterior pedicle screws was evaluated three days postoperatively by X-ray and CT imaging. The mean recovery rate as assessed by the Japanese Orthopaedic Association (JOA) score was recorded at final follow-up.
A total of fourteen anterior pedicle screws were implanted in our group. The average follow up period was 8 months. The mean JOA score was 12.5 preoperatively and 14.8 postoperatively. The mean improvement in the JOA score was 50.5% at final follow-up. The average local alignment improved from 4.0 of kyphosis preoperatively to 6.5 of lordosis at final follow-up. Early bony union was observed in four cases that were followed up for more than 3 months. There were no serious complications. No "pedicle perforation" was observed in any of the fourteen anterior pedicle screws, whereas one screw exposure occurred.
Anterior cervical pedicle screw implantation is a feasible method for selected cases. It provides another choice for strong anterior cervical reconstruction.
Orthopaedic Surgery 08/2011; 3(3):193-8.
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ABSTRACT: To retrospectively analyze the surgical effect of anterior approach bone graft and internal fixation methods for treating old thoracolumbar fracture without neurological symptom, so as to provide references for surgical treatment of such kind of fracture.
From April 2004 to April 2009, 22 cases of old thoracolumbar fractures were treated, including 15 males and 7 females with an average age of 38 years ranging from 21 to 56 years. The time from injured to operation was from 4 months to 2 years (average 8 months). Anterior approach surporting bone graft and internal fixation were performed. All patients were followed up for at least 12 months, the Cobb angle depending on lateral radiographs and VAS scores were compared between pre-operative and post-operative. Complication was observed.
The average preoperative Cobb angle of kyphosis was (15.0 +/- 2.4) degrees (8.0 degrees to 28.0 degrees), VAS score was 7.0 +/- 0.7. The average two weeks after operation was (3.0 +/- 1.6) degrees (-2.0 degrees to 9.0 degrees), VAS score was 1.0 +/- 0.6. The average Cobb angle at one year after operation was (3.5 +/- 1.4) degrees (0.0 degrees to 12.0 degrees), VAS score was 1.2 +/- 0.6. There were statistically significant differences in the above indexes between preoperation and two weeks after operation (P<0.05), while no statistically significant difference was found between 2 weeks and 1 year after operation (P>0.05). Bony fusion were achieved in 21 patients, nounion were occurred in 1 patient, but without correction loss.
According to Cobb angle of kyphosis, anterior approach surporting bone graft and internal fixation is a reasonable strategy to treat old thoracolumbar fracture without neurological symptom.
Zhongguo gu shang = China journal of orthopaedics and traumatology 07/2011; 24(7):560-3.
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ABSTRACT: To explore the choice of operative approach for thoracolumbar burst fractures and evaluate its clinical effects.
From September 2005 to March 2009, the clinical data of 94 patients with thoracolumbar burst fractures were analyzed retrospectively. Including 59 males and 35 femals with an average age of 36.8 years (ranged from 20 to 63). The fractures were classified according to Denis classification: 17 cases of type A, 32 cases of type B, 6 cases of type C, 24 cases of type D, 15 cases of type E. Neurological injuries were classified according to ASIA classification: 3 cases of grade A, 4 cases of type B, 23 cases of grade C, 38 cases of grade D, 26 cases of grade E. Among the patients, 42 cases were treated with reduction, decompression, internal fixation with pedicle-screw through posterior approach, meanwhile, of them, 18 cases with posterior-lateral bone graft fusion; 36 cases were treated with decompression, bone graft, through anterior approach, of them, 16 cases with TSRH system fixation and 20 cases with Zeplate system fixation; 16 cases (because of bone block intruded into vertebral canal leading to spinal cord compression ) were treated with anterior and posterior approach, internal fixation with pedicle-screw through posterior approach and subtotal vertebrectomy, decompression, titanium mesh cages bone graft fusion through anterior approach, meanwhile, of them, 8 cases with screw-rod and titanium steel plate system fixation.
All patients obtained good results and were followed up from 9 to 52 months with an average of 22.8 months. Cobb angle were corrected from preoperatively (25.00 +/- 5.50) degrees to postoperatively (4.20 +/- 1.80) degrees. Height of anterior and posterior border of vertebral body improved from preoperatively (50.80 +/- 2.82)%, (79.30 +/- 3.08)% to postoperatively (94.85 +/- 1.80)%, (98.20 +/- 1.40)%, respectively. The ratio of protruded bones to the spinal canal anteroposterior diameter decreased from preoperatively (33.10 +/- 1.40)% to postoperatively (6.70 +/- 1.50)%. Sagittal abnormity were corrected; posterior convex angle and height were no markedly lost during follow-up; no internal fixation loosening and titanium mesh displacement were found. In the aspect of never function, except for 1 case of grade A there is no recovered others obtained different improvement, among them, from grade A to B was in 2 cases; B to C, D was in 2,2, respectively; C to D, E was 16,7, respectively; D to E was in 38 cases.
The two factors decide surgical methods:the integrity of posterior ligamentous complex and nervous system function. Anterior approach refers to patients with incomplete spinal cord injury and anterior vertebral canal compression; posterior approach refers to patients with injury of posterior ligamentous complex; combination with anterior and posterior approach refers to patients with two injury factors.
Zhongguo gu shang = China journal of orthopaedics and traumatology 07/2011; 24(7):547-52.
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ABSTRACT: To investigate the incidence, predisposing factors and therapeutic modalities of acute colonic pseudo-obstruction (ACPO) in patients after total hip arthroplasties (THA) and total knee arthroplasties (TKA).
From January 2006 to December 2009, 12 patients with ACPO after THA and TKA operation were investigated retrospectively,who were viewed as the ACPO group. There were 10 males and 2 females with an average age of (78 +/- 12) years in the ACPO group. Other 853 patients without ACPO after THA and TKA operation were viewed as the control group treated at the same period. The incidence of ACPO was calculated. The clinical data were collected and compared between the two groups including patient age, gender, procedure, anesthetic class, clinical presentation, radiographic findings, duration from index surgery to diagnosis of ACPO, treatment, postoperative mobilization time, and length of hospital stay.
The incidence of ACPO was 1.4%. The incidence of primary THA (1.3%) was higher than that of primary TKA (0.4%); the incidence of hip and knee revisions (5.0%) was higher than that of primary THA and TKA (1.0%); there was no difference in incidence between hip revisions (5.5%) and knee revisions (4.0%). The mean age was (78 +/- 12) years old in ACPO group and (71 +/- 13) in the control group. The male/female ratio was 5:1 in ACPO group and 2:3 in control group. There were statistical differences in mean age and gender ratio between the two groups. No association was found with respect to anesthetic class. On average, ACPO occurred at 2.5 days after index surgery. The abdominal distention occurred in all 12 cases, nausea or vomiting in 8 cases and abdominal pain in 3 cases. Radiographically cecal dilation occurred in all cases and intestinal dilation in 3 cases. All patients initially were treated conservatively with immediate cessation of oral intake,a nasogastric tube and oral mineral oil. Three patients received a rectal tube. Only 1 patient required endoscopic decompression. There were no deaths after ACPO in the series. Mean mobilization time after surgery averaged (5.0 +/- 2.2) days in ACPO group compared with (2.5 +/- 1.1) days in the control group. Mean hospital stay averaged (16.5 +/- 6.4) days in ACPO group compared with (10.5 +/- 4.5) days in the control group. There were statistical differences in mean mobilization time after surgery and mean hospital stay between two groups.
ACPO mainly happened in old male patients. The majority cases response to conservative treatment and their prognoses are good. But ACPO will delay mobilization time after surgery and increase hospital stay.
Zhongguo gu shang = China journal of orthopaedics and traumatology 06/2011; 24(6):456-8.
