ABSTRACT
Objective:To investigate the clinical significance of a new classification system for atlas fractures based on pre- and post-treatment CT features, with a focus on diagnosis and treatment.Methods:A retrospective analysis was conducted on 75 cases of cervical vertebra fractures treated at the Sixth Hospital of Ningbo City between January 2015 and December 2020. The study included 44 males and 31 females, with an average age of 53.3±13.0 years (range: 27-81 years). The fractures were classified according to the Landells classification, resulting in 12 cases of type I, 13 cases of type II, 33 cases of type III, 9 cases that were difficult to classify due to fracture lines located at anatomical junctions, and 8 cases that could not be classified using the Landells classification due to diverse injury mechanisms. To establish a new preliminary classification for cervical vertebra fractures, the researchers considered whether the fracture line in the CT images involved the facet joint surface of the atlas, the impact on bilateral half-rings, and the displacement distance of the fracture ends. Five spinal surgeons were randomly selected to classify the CT images of the 75 patients using the new classification method. After one month, the imaging data of the 75 cases of cervical vertebra fractures were randomized and reclassified to assess the reliability and repeatability of the classification.Results:The new cervical vertebra fracture classification method comprised three types based on whether the fracture line involved the facet joint surface of the atlas: type A (no involvement of the facet joint surface of the atlas), type B (involvement of one side of the facet joint surface with intact contralateral half-ring), and type C (involvement of one side of the facet joint surface with fractured contralateral half-ring). Additionally, based on the maximum displacement distance between the fracture ends (>4 mm), six subtypes were identified: subtype 1 (≤4 mm displacement) and subtype 2 (>4 mm displacement). Consequently, the subtypes were classified as A1, A2, B1, B2, C1, and C2. According to the new classification method, the 75 patients included 17 cases of A1, 12 cases of A2, 7 cases of B1, 13 cases of B2, 12 cases of C1, and 14 cases of C2. The classification demonstrated excellent consistency, as assessed by the five doctors, with Kappa values of 0.85 and 0.91 for reliability and repeatability, respectively. At the final follow-up, all conservatively treated patients achieved bone healing, while four surgically treated patients experienced non-union of the fracture ends but exhibited good fusion between the atlas and axis. The remaining surgically treated patients achieved bony union without complications such as loosening or fracture of internal fixation.Conclusion:The new cervical vertebra fracture classification method, based on CT imaging features, comprehensively covers common clinical cases of cervical vertebra fractures and demonstrates excellent consistency. It provides valuable clinical guidance for the diagnosis and treatment of cervical vertebra fractures.
ABSTRACT
In recent years,the surgical treatment of thoracolumbar fractures has made great progress.The thoracolumbar injury classification and severity score (TLICS) of thoracolumbar injuries and the new AO classification,as the most widely used classification score in clinical application,have a clear guiding significance for clinical treatment and scientific research.With the extensive application of CT and MRI,the divergence in the diagnosis of posterior ligament complex (PLC) injury in scoring systems has been narrowed.With the wide application of pedicle screw and the deeper understanding of the anatomical and mechanical characteristics of spine,posterior pedicle screw fixation has been gradually adopted as the major method,while anterior or posterior pedicle screw fixation is only used in special cases.Because of the in-depth study of pedicle screw mechanics,more and more attention has been paid to the fixation of injured vertebrae.Moreover,with the intensive study of sagittal balance of the spine,the reconstruction of injured vertebrae has been proposed as a new concept and further investigated.The author discusses thoracolumbar fracture scoring system,surgical approach,surgical fixation segment,bone graft reconstruction and minimally invasive treatment so as to provide some reference.
ABSTRACT
Objective@#To investigate the clinical effect of the reserve-flow anterolateral thigh perforator flap based on aesthetics concept to repair soft tissue defect around the knee joint.@*Methods@#From June 2016 to April 2017, 10 patients with skin and soft tissue defects around the knee joint were admitted to Mingzhou Hospital of Zhejiang University. The area of the soft tissue defects around the ankle were ranged from 5.0 cm × 3.0 cm to 11.0 cm × 7.5 cm after debridement. The anterolateral thigh perforator flaps were designed on the ipsilateral lateral thigh, according to the results of preoperative perforator detection. The reserve-flow anterolateral thigh perforator flaps based on aesthetic concept were used to repair the wound through the subcutaneous tunnel. The flaps were 5.5 cm × 3.5 cm to 12.0 cm × 8.0 cm in size. The donor sites were directly closed.@*Results@#The flaps of 9 patients completely survived, however, epidermal necrosis occurred to 1 patient, at the distal end of the flap, about 1 cm × 1 cm in size. It completely healed after dressing change for 1 week. The follow up time was from 8 to 15 months (mean 12 months). The flaps were satisfactory in appearance, good in the elasticity, nearly normal in color, and had protective sensation. The two-point discrimination perception ranged from 9 to 13 mm(mean 10 mm). The donor and recipient sites only remained linear scars, with no depression deformity. The lower limb functions were normal.@*Conclusions@#The reverse-flow anterolateral thigh flap based on aesthetic concept, is an alternative method to repair the soft tissue defect around the knee joint, and protect the donor site to the maximum extent.
ABSTRACT
Objective To evaluate the clinical efficacy of universal self-locking anatomical plate for acetabulum and pelvis (USAPAP) in the treatment of posterior acetabular fractures.Methods Data of 55 patients with posterior acetabular fractures who were treated with the USAPAP from January 2014 to January 2016 were retrospectively analyzed.There were 39 males and 16 females with an average age of 38.5 years old (range,17-82 years).There were 35 fractures on the left side while the other 20 fractures were on the right side,including 52 fresh cases and 3 old cases.According to Letournel-Judet classification,there were 32 cases of posterior wall,9 cases of transverse and posterior wall,5 cases of anterior column and posterior wall,2 cases of posterior column,2 cases of transverse,2 cases of two columns,1 case of anterior column and posterior hemitransverse,2 cases of Pipkin type Ⅳ.All patients were managed operatively by the USAPAP,which allows simultaneous fixation for two columns and quadrilateral surface fractures through a single Kocher-Langenback approach.The quality of reduction was assessed by Matta's score system.The mean follow-up period was 18.5 months (range,12-24 months).Average operation time was 95 min,and average blood loss was 350 ml.Average operation time of plate and screws fixation was 19 min,and average fluoroscopy times in the surgery was 2 times.The mean time of bony union was 4.3 months.According to the criteria described by Matta,the excellent and good rate of radiological score was 92.7％ (51/55),including 39 cases excellent,12 cases good and 4 cases poor.The excellent and good rate of Merle d'Aubigne-Postel score was 87.3％ (48/55),including 35 cases of excellent,13 cases of good,5 cases of fair,and 2 cases of poor.Heterotopic ossification occurred in 1 patient (Brooker type Ⅱ) at three months postoperatively.One case with Pipkin type Ⅳ fracture underwent total hip arthroplasty due to femoral head necrosis at seven months postoperatively.Complications including wound infection,sciatic nerve injury,screw invade joint,redisplacement of the fracture,avascular necrosis of bone fragment,hardware failure,nonunion or malunion was not found in any case at the latest follow-up.Conclusion The USAPAP through the single posterior Kocher-Langenback approach provides strong and stable fixation for complex acetabular fractures associated with posterior region including posterior wall,both columns and quadrilateral surface.Satisfactory clinical results can be achieved by the use of this method.
ABSTRACT
Objective To investigate the clinical outcomes of pedicle screw fixation assisted with the 3D printing positioning guide template for treatment of unstable atlas fractures.Methods A retrospective case series review was made on 10 patients with unstable atlas fractures undergone direct posterior C1 pedicle screw fixation assisted with the 3D printing drill guide template from September 2012 to May 2015.There were 7 males and 3 females,with a mean age of 52.6 years (range,23-75 years).All patients complained of neck pain,stiffness and decreased range of motion without neurologic deficit.Preoperative skull traction was used routinely.After the three-dimension reconstruction of cervical vertebrae,ideal trajectory for C1 pedicle screws was designed with a complementary basal template for posterior surface of atlas corresponding anatomical structure.Then the drill guide template was materialized in a rapid prototyping machine and used during operation.Start point and direction of the ideal and actual trajectories were measured after matching the position of the pre-and post-operative patients' cervical spine.Safety of pedicle screw fixation was assessed in the transverse and sagittal planes of CT scan.Operation time and blood loss were recorded.Visual Analogue Scale (VAS) of neck pain was recorded before operation and 3 months after operation.Clinical efficacy,fracture reduction,stability and surgical complications were reviewed at the follow-up.Results A total of 20 screws were inserted safely.No significant differences existed in deviation of entry point and direction between ideal and actual trajectories (P ＞0.05).Operation time was 60-90 min (mean,75 min) and intraoperative blood loss was 110-300 ml (mean,160 ml).No spinal cord or vertebral artery injury was noted during operation.All patients were followed up for 12-36 months (mean,20.5 months).VAS was improved from preoperative 7.3 (6.3-9.5) points to 1.4 (0.3-2.5) points 3 months after operation (P ＜ 0.05).All patients had normal range of motion of the cervical spine 3 months after operation.Bony fusion was achieved 6 months after operation.At the follow-up,good cervical alignment was maintained with no instrument failure and C1.2 instability.Conclusion For treatment of unstable atlas fractures,direct posterior C1 pedicle screw fixation assisted with the 3D printing drill guide template can improve the precision of screw placement,reduce complications,and preserve the function of the occipital-atlantoaxial junction.
ABSTRACT
Objective To compare the clinical efficacy and fusion rate of unilateral and bilateral C1 and C2 pedicle screw fixation of unstable Jefferson fractures.Methods This retrospective casecontrol study enrolled 22 patients with unstable Jefferson fractures admitted between April 2012 and May 2015.There were 18 males and four females,with the mean age of 52.9 years (range,35-67 years).Mean preoperative visual analogue scale (VAS) was 6.09 points (range,4-8 points).According to the American spinal injury association (ASIA) classification,two patients were rated grade D and one patient grade C.Mean Japanese orthopedic association (JOA) score was 12.3 points.Bilateral C1 and C2 pedicle screw fixation was performed for 15 patients (bilateral group).Advantage side unilateral C1 and C2 pedicle screw fixation was performed for seven patients with extremely unstable fracture or narrow pedicle (unilateral group).Operation time,blood loss and surgical complications were recorded.VAS was used to evaluate the improvement of neck pain after operation.ASIA classification and JOA score were used to assess nerve function recovery.Atlanto-dental interval (ADI),srew position and bone fusion were evaluated after operation.Results All patients successfully completed the operation.Operation time was (119.5 ±21.2)min,and blood loss was (280.1 ±83.1)ml.A total of 74 screws were placed and CT scan showed satisfactory position of the screws.No complications were noted either during the operation or after surgery.All patients were followed up for mean 20.7 months (range,13-33 months).VAS was improved in both groups after operation (P ＜ 0.01),and there was no significant difference between the two groups (P ＞ 0.05).Two patients with ASIA grade D in bilateral group were improved to ASIA grade E after operation.One patient with ASIA grade C in unilateral group was improved to ASIA grade D after operation.JOA score increased to mean 15.7 points at last follow-up.ADI were decreased in both groups after operation(P ＜0.05),but there was no significant difference between the two groups (P ＞ 0.05).All patients had bony fusion 6 months after operation,with similar fusion rate between the two groups (P ＞ 0.05).Conclusion Advantage side unilateral screw fixation can be used for the patients with bilateral C1 and C2 pedicle screw fixation failure,for the technique can improve cervical pain and provide relatively high stability and fusion rate.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the biomechanical effects of the anterior cervical transpedicular-screw system (ACTPS), compared to the anterior cervical screw plate system (ACLP), in the subaxial cervical spine after 2-level corpectomy.</p><p><b>METHODS</b>A verified intact finite element subaxial cervical (C3-C7) model was established and analyzed by Mimics 10.0, Rapidform XOR3, Hypermesh 10.0, CATIA5V19, ANSYS 14.0 softwares based on the CT data (C1-T1) was collected from a 28 years old male volunteer. The axial force of 75 N and moment couple of 1N·m was loaded on the upper surface of C3, which made the model movement in flexion extension, lateral bending, rotating direction, respectively. Then, recorded the range of motion, and compared the results with the in vitro biomechanical experimental data to verify the effectiveness of the model. The ACTPS model and the ACLP model were analyzed using the finite element method. The range of motion at the operation segments (C4-C7), the range of motion at the adjacent segment (C3-C4) and stress distribution under flexion, extension, lateral bending, and axial rotation were calculated, and compared the range of motion with intact model.</p><p><b>RESULTS</b>There were 85,832 elements and 23,612 nodes in the intact model of subaxial cervical spine (C3-C7) in this experiment,and the range of motion of intact model validated with the reported cadaveric experimental data. In ACTPS group the stress was been well-distributed, but the stress concentrated on the interface between screw and the titanium plate in ACLP group. There were obvious differences of the maximum stress value between the two groups. The range of motion of fixed segments in ACTPS group was smaller than ACLP group, however adjacent segment range of motion showed no significant difference. Compared with the intact group, the range of motion in flexion extension, lateral flexion, rotation direction was decreased respectively about 25°, 20° and 8°, the range of motion at adjacent segment (C3-C4) was correspondingly compensated about 0.3°, 3° and 0.1°.</p><p><b>CONCLUSIONS</b>ACTPS is better than ACLP in terms of biomechanical properties. It offers rigid stability, and may be more suitable for reconstruction stability of 2-level and more than 2 levels corpectomy in the subaxial cervical spine. Meanwhile, the risk of fracture of ACTPS system is lower than that of the ACLP system.</p>
Subject(s)
Adult , Humans , Male , Biomechanical Phenomena , Bone Screws , Cervical Vertebrae , General Surgery , Finite Element Analysis , Models, Anatomic , Range of Motion, Articular , RotationABSTRACT
Objective To investigate the clinical effects of the posterior atlantoaxial pedicle screw fixation combined with unilateral axial spinous process and lamina screws and allogeneic bone graft for atlantoaxial instability.Methods From March 2010 to April 2014,data of 10 patients with atlantoaxial instability who had undergone atlanto-axial vertebral pedicle fixation and interbody fusion combined with posterior atlanto-axial spines lamina nails were retrospectively analyzed.There were 6 males and 4 females with an average age of 39 (range,16-62) years old.The inclusion criteria was atlantoaxial instability together with unilateral vertebral artery segment high cross deformity (7 patients) or atlantoaxial joint break bad involving unilateral pedicle (7 patients).3 patients have spinal cord disease symptoms and physical signs,both suffered limited neck mobility and pain.The VAS scores were 1-8,with an average of 3.70±2.11.Preoperative X-ray,CT three-dimensional reconstruction and MRI were collected.X-ray and CT examination were performed 7 d and 1,3,6,12 months after operation to evaluate the internal fixation and bone grafting fusion.Results There's no occurrence of cervical spinal cord and vertebral artery injury.Screws were successfully implanted.1 case's incision occurred infiltration liquid 3 days after operation.For allograft rejection consideration,we changed the plan,and the infiltrating stopped 5 days later.Other incisions were all primary healing.VAS scores were 1.01±0.89 after operation,which was significantly reduced.X-ray showed good recovery of cervical sequence after the operation,and CT revealed 1 patient with atlas pedicle screw in the medial cortex damage.Spinal canal was without infringing,and the other screw positions were normal.6 months after operation,X-ray or CT examination both showed bony fusion.Conclusion Atlantoaxial pedicle screw fixation combined with unilateral axial spinous process and lamina screws and allograft bone graft fusion for the treatment of atlantoaxial instability can observe good clinical effects.
ABSTRACT
Objective To investigate the optimal trajectory of posterior occipital condyle screw fixation via radiological and anatomical study.Methods Twelve adult craniocervical junction complete specimens were selected.The length,width and height of occipital condyle and the inclination angle of the longest axis were measured by CT scanning and reconstruction.Subsequently,occipital condyle screws were inserted with reference to CT measurements.After screw fixation,accuracy and safety of the placement of occipital condyle screw were verified by gross observation and CT scanning.Results Preoperative measurements of height and width of the occipital condyles indicated the placement of 4.0 mm bicortical screws was secure.Left vertebral artery horizontal sections of 2 specimens were slightly pressed without damage.CT scanning identified no damage to the inner or outer wall of the occipital condyle and the hypoglossal canal.Trajectory parameters between the right and left sides were slightly different,but no significant difference was observed (P ＞ 0.05).Average screw channel length and inclination angle were (20.8 ±2.6)mm and (37.1 ± 4.7)°respectively.Angle between screw and skull base tangent was observed as (8.5 ± 1.7) °.Distance between screw axis and hypoglossal canal was observed as (3.1 ± 1.1) mm.And the distance averaged (4.6 ± 1.4) mm between occipital condyle screw entry point and skull base and (6.1 ± 1.5) mm between entry point and inside edge of the occipital condyle.Conclusion Occipital condyle can be used as a new alternative fixed point in occipitocervical fusion.
ABSTRACT
OBJECTIVE@#To determine the effect of lung protection mechanical ventilation on respiratory function in the elderly undergoing spinal fusion.@*METHODS@#Sixty 70-85 year old patients, ASA class II or III, undergoing spinal fusion were randomly assigned into 2 groups (30 in each group): a protection mechanical ventilation group (group P) and a conventional mechanical ventilation group (group C). Low VT and low level positive end expiratory pressure (PEEP) mechanical ventilation were applied in group P (VT=6mL/kg, RR=12-18 b/min, I:E=1:2, PEEP=10 cmH2O, alveolar recruitment performed once every 15 min), while traditional ventilation was used in group C ( VT=10-12 mL/kg, RR=12 b/min, I:E=1:2). Arterial blood samples were taken and pH, PaO2, PaCO2, PaO2/FiO2, A-aDO2, HR, SBP, DBP and CVP were recorded before the operation (T0), 1 h after tracheal intubation (T1), tracheal extubation immediately (T2), 1 h after tracheal extubation (T3), 1 d, 2 d, and 3 d after the operation (T4, T5, and T6). The pulmonary complication was also examined 1 d after the operation.@*RESULTS@#At T1, T2, T3, T4 and T5, PaO2 and PaO2/FiO2 in group P were higher than those in group C, but A-aDO2 in group P was lower than that in group C. Five patients had bronchitis, 5 had hyoxemia, and 3 had atelectasis in group C, but 2 bronchitis in group P. The incidence of pulmonary complication was 43.3% in group C and 6.6% in group P. There was no significant difference in HR, SBP, DBP and CVP between the 2 groups.@*CONCLUSION@#Lung protection mechanical ventilation improves the arterial oxygenation and accelerates the recovery of respiratory functions in elderly patients after spinal fusion operation, with no influence on hemodynamics.
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Anesthesia, General , Hypoxia , Positive-Pressure Respiration , Methods , Postoperative Complications , Pulmonary Ventilation , Respiration, Artificial , Methods , Respiratory Function Tests , Spinal Fusion , MethodsABSTRACT
Objective To analyze the feasibility and effect of combining intramedullary nails and plates in the treatment of ipsilateral unicondylar tibial plateau fractures with non.contiguous tibial shaft fractures.Methods From May 2003 to November 2005,21 patients with ipsilateral unicondylar tibial plateau fracture and non-contiguous tibial shaft fracture were treated with combining intramedullary nails and plates,including 15 males and 6 females,with the mean age of 34 years (range,20-55 years).The tibial plateau fractures were classified according to Schatzker et al.; 4 cases were type Ⅰ,11 cases type Ⅱ,6 cases type Ⅲ and 1 case type Ⅵ.Middle third tibial shaft fractures were in 13 patients,and distal third tibial shaft fractures were in 8 patients.Once the reduction was obtained,we first fixed tibial plateau with plate and then tibial shaft with medullary nail in 19 cases; in 2 cases,we first fixed the tibial shaft with medullary nail and then tibial plateau with plate.Results 1All patients were followed up for 0.9 to 4 years (average,2.2 years).Bone union was obtained in all patients.The tibial plateau fractures united after an average of 12 weeks,and the tibial shaft fractures united after an average of 29 weeks.Delayed union of the tibial shaft fracture occurred in 3 patients,and the fracture healed finally by removing the proximal locking.Tibial plateau malunion occurred in one patient due to malreduction.According to HSS scores,excellent result was obtained in 17 patients (80.95％),good in 3 patients (14.29％),fair in 1 patient (4.76％).Conclusion With careful attention to some techniques,ipsilateral unicondylar tibial plateau fractures with non-contiguous tibial shaft fractures can be treated successfully by combining medullary nail and plate.
ABSTRACT
Objective To investigate the preliminary clinical application of anterior pedicle screws in treatment of the lower cervical spine injuries. Methods The study involved 22 patients with lower cervical spine injuries treated with anterior pedicle screw technique from January 2009 to December 2011.X-ray and CT images of the patients were taken postoperatively to evaluate whether the position,orientation and length of the screws were appropriate and whether there involved pedicle cortex perforation,transverse foramen or spinal canal invasion.MRI was also performed to ascertain the situation of decompression,the formation of epidural hematoma and the degeneration of cervical spinal cord.The improvement of JOA score was compared statistically. Results All the patients were followed up for 3-36 months ( mean,15.5 months).A total of 44 anterior lower cervical screws were implanted and all screws were inserted smoothly.All the patients had bone healing after average 4.5 months,which showed no loosening,prolapse or breakage of the screws or no loosening of the plate.One patient showed hoarseness postoperatively,which was probably due to the long-term distraction of recurrent laryngeal nerve.The symptom disappeared at around three weeks after neurotrophic support.Two patients complained of dysphagia postoperatively,and were informed of keeping a soft diet.The symptom was remarkably alleviated after three months or so.The X-ray films indicated satisfactory position of the implanted screws.Before discharge,the transaxial CT images showed that two screws perforated the medial pedicle cortex ( 1 ° ) and that two screws perforated the lateral cortex (1 °) and affected the medial margin of the transverse foramen.Before discharge,the MRI indicated obvious alleviation of the anterior spinal cord compression in all patients and a small amount of anterior epidural hematoma in four patients,with no obvious spinal cord compression.At 12 months after operation,the MRI showed significant improvement of spinal cord degeneration in three patients.JOA score was increased from preoperative (8.5 ± 0.7) to ( 14.5 ± 0.8 ) before discharge (P ＜0.01 ).JOA score was (15.7 ±0.7) at six months postoperatively,which was significantly improved as compared with that before discharge. Conclusions Anterior pedicle screw fixation is a reliable and safe method for reconstruction of the anterior lower cervical injuries.Surgical indications should be strictly controlled in its clinical application.
ABSTRACT
Objective To explore the clinical outcomes of anterior plate fixation through transoral approach in the treatment of unstable atlas fractures.Methods From March 2004 to May 2010,20 patients with unstable atlas fractures were treated by anterior plate fixation through transoral approach,including 12 males and 8 females,aged from 23 to 68 years (average,47.7±13.9 years).Of the 20 cases of unstable atlas fractures,4 cases were classified as anterior 1/2 Jefferson fracture,8 cases as 1/2 ring Jefferson fracture,and 8 cases as anterior 3/4 ring Jefferson fracture.The preoperative average VAS scores were 6.0±1.3 points,ranged from 4 to 8 points.Clinical and imaging examinations were performed during follow-up period to evaluate the outcomes.Results All patients were followed up for 12 to 81 months,with an average of 48.5±20.0 months.There were no screw loosing and breakage,no plate displacement,and no spinal cord and vertebral artery injury during operation.A total of 20 plates were placed and all 40 screws were inserted into atlas lateral mass.Computed tomography scans demonstrated 2 screws were placed too close to the vertebral artery canal,but without clinical consequences.The postoperative VAS scores were from 0 to 3 points with an average of 1.3±1.0 points.Static and dynamic films 6 months after surgery demonstrated that fusion was achieved in all cases.Atlantoaxial rotational function was restored satisfactorily.No plate-related complication was observed in all patients in the whole follow-up period.Conclusion Anterior plate fixation through transoral approach is an effective method for management of unstable atlas fractures,which has advantages such as solid bony fusion and low incidence of complication.
ABSTRACT
Objective To compare the biomechanical pull-out strength (POS) of three different fixations in upper thoracic vertebras using translaminar screws (TLS), translaminar facet screws (TLFS), and transpedicle screws (TPS), respectively. Methods Nine fresh human cadaveric cervicothoracic junction spines specimens which including T1-T3 vertebras were harvested. The vertebras specimens were scanned using dual-energy radiograph absorptiometry for bone mineral density. Both of screw insertion techniques at each vertebrae was randomized. All the screw insertions were based on direct observation and the CT scan on the pedicles. The peak of insertional torque (IT) was recorded and axial pull-out testing was performed to simulate intraoperative failure of fixation. Results The mean peak IT of the TFLS, TPS and TLS were (0.43±0.01), (0.40±0.01), (0.35±).01) N·m, respectively. There was no statistically significant difference between the TFLS and TPS, and between the TPS and TLS was same. But the TFLS generated statistically greater peak 1T in comparison with the TLS(t=-13.86, P＜0.05). The mean POS of TLFS was (771±106) N,which had no statistically significant difference in comparison with the TPS(733±65) N. And the TLS (663±86) N was same. But the TFLS generated statistically greater POS in comparison with the TLS (t=9.907, P＜0.05). The peak IT showed a strong positive correlation with POS in three screw techniques. Bone mineral density correlation with POS in all methods of fixation. Conclusion It was not a significant difference to compare POS of TLS and TLFS to that of TPS respectively. TLS and TLFS appear to be a biomechanically sound alternative in the upper thoracic spine, and appear to be a safe and effective technique for instrumenting the upper thoracic spine.
ABSTRACT
Objective To identify the feasibility and the anatomical parameters of posterior transarticular pedicle screw fixation in the thoracic spine, provide a reference for clinical applications. Methods Twenty human cadaveric thoracic spine segments were dissected posteriorly and anteriorly, with care taken to expose the laminas and pedicles. The entrance point of transarticular pedicle screws was located in the 7 mm away from the above at the inferior margin of the lamina and the inside at the exterior margin, respectively. Posterior transarticular pedicle screws implantation was performed under direct visualization into T1,2,T5,6 and T9,10 Under direct abservation, the feasibility of posterior transarticular pedicle screw fixation was assessed. Then a CT was done. On the morphologic CT scan, the angle and length of the transarticular pedicle crew trajectory were measured. Results The thoracic transarticular pedicle screw trajectory were caudal tilting in the sagittal plane and lateral tilting in the axial plane with successful placement. Screws were placed across the facet joint, and from the inferior articular process of upper thoracic vertebra into the pedicle of lower thoracic vertebra. There was little difference between different number of thoracic vertebrae of the angle, but without significance. The average angles of the screws were 41.4°+3.2°caudal tilting in the sagittal plane and 2.1°±0.7° lateral tilting in the axial plane. The average trajectory lengths were (40.6±4.9)mm, and the lengths increased gradually from upper thoracic vertebra to middle and lower. There were significant differences statistically among T1,2, T5,6 and T9.10 (F=74.09, P＜0.01 ). Conclusion Posterior transarticular pedicle screw fixation is feasible, and there are some directions for implantating the screws. Transarticular pedicle fixation in the thoracic spine affords an alternative to standard pedicle screw placement for thoracic stabilization.
ABSTRACT
ObjectiveTo investigate application of the anterior cervical pedicle screw in the lower cervical spine.MethodsTwenty disarticulated human vertebrae(C3-C7) were evaluated with computed tomography for pedicle morphometry Parameters included vertebral body height,vertebral body depth,vertebral body width,outer pedicle width,outer pedicle height,pedicle axis length,transverse section angle,sagittal section angle,transverse intersection point distance and sagittal intersection point distance.On the basis of these data,the screw channel was determined and the screws were inserted in the specimen.Five patients underwent surgical reconstruction using anterior pedicle screw fixation.After surgery,physical examination and roentgenograms and CT scans were performed in all patients.ResultsThe transverse section angle increased from C3(45.7°±4.0°) to C5(52.1°±5.9° ),but decreased from C6(47.8°±6.7°) to C7(44.4°± 8.3°).The sagittal section angle gradually increased from C3 (93.4°±7.2°) to C6( 112.1°±6.2°) but decreased a little to C7(102.7°±8.5°).The distances in transverse section was about 1.97-3.98 mm and in sagittal section was 3.4-7.5 mm.Anterior pedicle screws were inserted successfully in all specimens without critical pedicle wall perforations.Patients were permitted to ambulate the next day after surgery with a cervical collar.Postoperative neurological improvement was observed in all cases.Postoperative radiographic evaluation confirmed proper insertion of anterior pedicle screws without pedicle perforaton.The average follow-up time was 10.6 months.No anterior pedicle screw breakage and loosening was observed.ConclusionThe entry point in anterior pedicle screw should located in 5mm to upper endplate and near anterior median line.The transverse section angle should be 45.7°-52.1°and the sagittal section angle should be 93.4°-112.1°.The lengths of the screw should be about 32 mm.
ABSTRACT
ObjectiveTo evaluate the clinical effects of transforaminal lumbar interbody fusion (TLIF) or posterior lumbar interbody fusion(PLIF) using microendoscopic discectomy under X-Tube system in treatment of lumbar degenerative disc diseases.MethodsFrom December 2007 to April 2008,32 patients with low back disorders were treated by microendoscopic discectomy TLIF or PLIF under X-Tube system,including 19 cases in TLIF and 13 in PLIF.Etiologies including lumbar disc herniation combined with segmental instability in 21 cases,and spondylolisthesis in 11 cases.All patients were under regular postoperative follow-up and radiological examination.The clinical functional outcomes were evaluated according to Oswestry disability questionnaire.ResultsThe mean operation time was 120 min(range,90-180),and the average blood loss was 190 ml (range,100-400).There were no complications,such as infection and internal fixation failure.Bony fusion was achieved in all patients.The follow-up was from 14 months to 41 months with 21 months in the average.The average 0swestry scores decreased from preoperative 40.1％±4.1％ to 9.5％±3.7％ three months after the operation.The outcomes of this operation were rated as excellent.ConclusionMicroendoscopic discectomy TLIF or PLIF under X-Tube system in treatment of lumbar degenerative disc diseases has the characteristics of less blood loss,tissue trauma and quick recovery.
ABSTRACT
Objective To evaluate the clinical effect and safety of the occiput-cervicle or C1-C2 internal fixation and bone graft fusion in treatment of the unstable atlas fracture.Methods A retrospective study was performed in 38 patients with unstable atlas fractures treated by the occiput-cervicle or C1-C2 internal fixation and bone graft fusion from October 2004 to March 2009.Six patients with comminuted atlas fracture combined with instability of the occipito-atlantoid articulations were treated with occiput-C2 fusion(five patients)and with occiput-C3 fusion(one patient).There were seven patients with typical Jefferson fractures,three with semiring fractures,eight with atlas fractures combined with Anderson type Ⅱ odontoid process fractures,three with atlas fractures combined with Hangman's fractures (two patients with Levine and Edwards type Ⅲ Hangman's fractures were treated with occiput-C3 fusion and one patient Levine and Edwards type Ⅱ Hangman's fracture was treated with C1-C2 fusion),three with atlas fracture combined with lower cervicle injury,six with rupture of transverse ligament combined with instability of atlanto-axial joint(Dickman transverse ligament type Ⅰ injury)and two with comminuted fracture of the lateral mass associated with bony avulsion of the medial tubercle and transverse ligament(Dickman transverse ligament type Ⅱ injury).Of all,five patients were treated with occiput-C2 fusion,three treated with occiput-C3 fusion and 30 treated with C1-C2 fusion.Results All the patients were followed up for a range of 12-46 months(average 28 months),which showed improvement of clinical symptoms in some extent postoperatively.The operation time ranged from 80 to 190 min ates(average 135 minates),with intraoperative blood loss for 200-3 300 ml(average 460 ml)and average fluoroscopic time for 60 seconds.There were no neurological deficits,vertebral artery related complications or other complications in all the patients during the surgical operation.No neurological deficit was aggravated after the patient's mobilization with brace three days after operation.The enous plexus of blood vessel at C1-C2 rupture induced by the use of electrocautery was found in three patients who showed no cerebral hemodynamic deficit after hemostasis with hemostatic sponge and cotton piece.The follow-up X-ray and CT manifested osseous fusion in all the patients,with no looseness or breakage of the screws.The late follow-up showed pain associated with movement and limited range of motion in four patients(11%)and occipital neuralgia in one.Conclusions An occiput-cervicle fixation fusion or a C1-C2 fixation fusion combined with short external fixation can reestablish the upper cervical stability and prevent further injury of the spinal cord and nerve function and hence is an ideal option for C1 burst fracture with or without rupture of the transverse ligament.
ABSTRACT
Objective To investigate feasibility and safety of anterior pedicle screw fixation tunnel in the axis so as to provide theoretic evidence for further clinical application.Methods Thirty-two dry axis specimens were used for anterior pedicle screw placement,and the length of pedicle crews tunnel was measured by a digital caliper.The extraversion angle and the downslope angle were determined by CT cross-sectional scanning and reconstruction.Results All the anterior pedicle screws were positioned well,with no perforation of the pedicle.The anchoring point was at the vertex between the vertebral body and the superior articular process,with axis pedicle length of(28.4 ± 2.5)mm,the extraversion angle of (28.5 ±2.3)°and the downslope angle of(15.5 ±2.0)°.Conclusions Anterior pedicle screw fixation tunnel is feasible in the axis and can keep away from some important anatomy structures including transverse foramen,vertebral artery groove and vertebral canal to provide large safety space.
ABSTRACT
Objective To assess clinical curative effect of three types of combined posterior atlantoaxial internal fixation techniques in treatment of atlantoaxial instability. Methods The study involved 68 patients with atlantoaxial instability treated with different fixation techniques from August 2002 to March 2008. ( 1 ) Transpedicular fixation was performed in 32 patients including 20 patients with Anderson Ⅱ odontoid fractures (seven with old odontoid fracture and 13 with fresh fractures), six with type Anderson Ⅲ fresh odontoid fractures, four with disrupt of transverse ligament of the atlas and two with congenital loose odontoid process combined with atlantoaxial instability. (2) Transpedicular internal fixation with screws of atlas incorporating C2 laminar screws was performed in 20 patients with upper cervical injury including eight with type Ⅱ odontoid process fractures combined with atlantoaxial backward dislocation,four with type Ⅱ odontoid process fractures combined with atlantoaxial forward dislocation, two with nonunion of odontoid process fractures, three with type Ⅲ odontoid process fractures combined with atlantoaxial unsteadiness and three with atlantoaxial dislocation combined with disrupt of transverse ligament of atlas. (3)A total of 16 patients with traumatic atlantoaxial instability, reducible atlantoaxial dislocation and irreducible atlantoaxial dislocation were treated with four-point internal fixation technique using autologous iliac bone grafts. Results (1) A total of 120 screws were implanted in 32 patients, with no spinal cord or vertebral artery injury after surgery. Atlas lateral mass fixation was adopted in three patients because of broken posterior arch of the atlas. Postoperative CT showed that two screws were inserted into the vertebral artery hole and that one screw was inserted medially into the spinal canal and caused medial correx rupture, but both with no clinical symptoms. All 32 patients were followed up for 6-42 months ( average 26 months), which showed solid fusion in all patients. The postoperative JOA scores ranged from 13.2 points to 16.8 points (average 14. 8 points). (2) Thirty-two screws were implanted in 20 patients,with no spinal cord or vertebral artery injury. The patients were followed up for mean six months ( range 6-14 months). Postoperative X-ray showed sound bone fusion, with no cervical instability, loosening or breakage of the screws. (3) The symptoms of all the patients were improved at different degrees, with no neurological deterioration or severe complications, such as nerve blood vessel injury. All 16 patients were followed up for 8-26 months ( average 16 months), which showed bony fusion in all patients at 3-6 months after surgery. The spinal cord function was improved markedly in five patients, good in eight, mild in two but unchanged in one. Conclusions Three types of combined posterior atlantoaxial internal fixation techniques have advantages of rigid, short-segmental and three-dimensional fixation and hence are effective methods for treatment of upper cervical injuries. The combination mode can be varied according to specific condition of the patients.