Screw Fixation Technique Research Articles

Surgical outcomes of mini-open Wiltse approach and conventional open approach in patients with single-segment thoracolumbar fractures without neurologic injury.

This study aimed to introduce a novel mini-open pedicle screw fixation technique via Wiltse approach, and compared it with the traditional posterior open method. A total of 72 cases of single-segment thoracolumbar fractures without neurologic injury underwent pedicle screw fixation via two different approaches. Among them, 37 patients were treated using posterior open surgery, and 35 patients received mini-open operation via Wiltse approach. Crew placement accuracy rate, operative time, blood loss, postoperative drainage, postoperative hospitalization time, radiation exposure time, postoperative improvement in R value, Cobb's angle and visual analog scale (VAS) scores of the two methods were compared. There were no significant differences in the accuracy rate of pedicle screw placement, radiation exposure and postoperative R value and Cobb's angle improvement between the two groups. However, the mini-open method had obvious advantages over the conventional open method in operative time, blood loss, postoperative drainage, postoperative hospitalization time, and postoperative improvement in VAS. The mini-open pedicle screw technique could be applied in treatment of single-segment thoracolumbar fracture without neurologic injury and had advantages of less tissue trauma, short operative and rehabilitative time on the premise of guaranteed accuracy rate and no increased radiation exposure.

The surgical management of traumatic lower cervical spondylolisthesis with posterior percutaneous pedicle screw fixation.

We reported a technical report of traumatic lower cervical spondylolisthesisca used by bilateral pedicle fracture, without neurological compression. The patient was treated with the minimally invasive technique of percutaneous pedicle screw fixation. Fracture healing and normal cervical motion were confirmed by plain films and physical examinations on the 18-monthpostoperatively. The technique of percutaneous pedicle screw fixation might be an alternative strategy for the treatment of traumatic lower cervical spondylolisthesis with pedicle fracture.

Cortical and Standard Trajectory Pedicle Screw Fixation Techniques in Stabilizing Multisegment Lumbar Spine with Low Grade Spondylolisthesis.

Cortical screw (CS) fixation has been recently proposed as an alternative to the standard pedicle screw (PS) fixation technique. Biomechanical studies involving individual screw pullout and single level motion segment stabilization showed comparable performance of both techniques. However, whether this new fixation technique can be applied to the stabilization of multilevel lumbar segments with significant destabilization has been unclear. To compare stability of CS fixation to the traditional PS fixation in an unstable 3 level spondylolisthesis model. This is a biomechanical study comparing cortical trajectory pedicle screw fixation to traditional trajectory pedicle screw fixation in an unstable cadaveric model using nondestructive flexibility test. Eight fresh frozen cadaveric lumbar spines (T12- S1) were obtained. After intact baseline testing, a 3-level lowgrade spondylolisthesis was simulated at the L1-4. Each specimen was instrumented with the PS and CS fixation systems. Standard nondestructive flexibility test was performed. Range of motion at each level was compared between the constructs during flexion-extension, lateral bending, and axial rotation. The destabilization model significantly increased the ROM in all planes (P<0.05). Both fixation techniques provided significant reduction in the ROM (P<0.05). There was no significant difference in ROM between the PS and CS groups in any of planes (P>0.05). Cortical trajectory pedicle screw fixation provided stabilization to multilevel lumbar segment with low-grade spondylolisthesis comparable to the standard trajectory pedicle screw construct.

Minimally Invasive Dynamic Hip Screw (MIDHS) Fixation

Use of a dynamic hip screw is the preferred mode of treatment for intertrochanteric fractures. Minimally invasive and small incision surgeries are routinely performed in orthopedics. The authors describe here the minimally invasive dynamic hip screw fixation technique for intertrochanteric fractures of the femur.

Percutaneous posterior transdiscal oblique screw fixation with lateral interbody fusion: a radiological and cadaveric study.

To design and investigate a novel technique of percutaneous posterior transdiscal oblique screw fixation with lateral interbody fusion. CT scans of 45 patients were collected and imported into Mimics software for three-dimensional (3D) reconstruction. Cylinders were drawn to simulate the trajectory of the oblique screw. Six measurements were obtained for each unit to design a right size cage: a the distance between the intersection of the simulated trajectory of the screw with the inferior border of the upper vertebra and its anteroinferior corner; b the distance between the intersection of the simulated trajectory of the screw with the superior border of the inferior vertebra and its anterosuperior corner; h the height of the intervertebral space; θ the angle between simulated trajectory of screw and the upper endplate of inferior vertebra; uw: the width of the inferior endplate of upper vertebra; iw: the width of upper endplate of inferior vertebra. Three intact adult fresh-frozen cadaveric specimens were obtained, percutaneous posterior transdiscal oblique screw fixation was performed under X-ray apparatus, and interbody cage was implanted by assistance with special self-retaining retractor system and endoscope. According to the results of data measured from 3D images, trapezoid shape interbody cages with suitable size were designed. Percutaneous posterior oblique screw fixation with lateral interbody fusion was performed on three cadaveric specimens successfully. Using specially designed trapezoid shape interbody cages, assisted by intra-operative image intensification and endoscope, it is feasible to perform percutaneous posterior transdiscal oblique screw fixation with lateral interbody fusion technique.

Treatment of fixed atlantoaxial dislocation and basilar invagination with C1-2 screw and rod reduction and fixation technique

To introduce a novel technique of reducing fixed atlantoaxial dislocation (FAAD) and basilar invagination (BI) with C1-C2 screw and rod system. From January 2009 to December 2011, 26 patients of FAAD and BI were reduced successfully with an insertion of C1 lateral mass and C2 pedicle/pars screw and rod system. The cohort had 17 females and 9 males. And their most common presenting symptoms were extremity muscle weakness, restricted neck movement and paresthesia. All of them achieved effective reduction. Among them, 18 attained complete reduction and 8 partial reduction (over 60% extent of reduction). The mean atlanto-dental interval (ADI) value was 2.1 mm postoperatively versus 8.8 mm preoperatively (t = 21.1, P < 0.01) . All of them had relieved compression of dura and medulla oblongata and cervical cord. All clinical symptoms improved. One case had pulmonary infection while another case delayed healing of incision. Both recovered well after symptomatic treatments. Bony fusion reached 100% during a mean follow-up period of 22 months. The C1-C2 screw and rod system may achieve effective reduction and fixation for FAAD and BI. Capable of preserving atlanto-occipital joints in patients without atlas assimilation, this procedure provide more solid immobilization than occipitocervical fusion in those with atlas assimilation.

Lumbar pedicle cortical bone trajectory screw.

The purpose of this study was to demonstrate the lumbar pedicle cortical bone trajectory (CBT) screw fixation technique, a new fixation technique for lumbar surgery. The data analyzed in this review are mainly from articles reported in PubMed published from 1994 to 2014. Original articles and critical reviews relevant to CBT technique and lumbar pedicle fixation were selected. CBT technique was firstly introduced as a new fixation method for lumbar pedicle surgery in 2009. The concepts, morphometric study, biomechanical characteristics and clinical applications of CBT technique were reviewed. The insertional point of CBT screw is located at the lateral point of the pars interarticularis, and its trajectory follows a caudocephalad path sagittally and a laterally directed path in the transverse plane. CBT technique can be used for posterior fixation during lumbar fusion procedures. This technique is a minimally invasive surgery, which affords better biomechanical stability, fixation strength and surgical safety. Therefore, CBT technique has the greatest benefit in lumbar pedicle surgery for patients with osteoporosis and obesity. CBT technique is a better alternative option of lumbar pedicle fixation, especially for patients with osteoporosis and obesity.

Functional recovery of elderly patients with surgically-treated intertrochanteric fractures: preliminary results of a randomised trial comparing the dynamic hip screw and proximal femoral nail techniques

IntroductionIntertrochanteric fractures of the femur are prevalent in the elderly, and leave patients with functional restrictions after surgical treatment. The aim of this study was to compare the functional recovery at 1-year follow-up of elderly patients with intertrochanteric fractures treated surgically with the dynamic hip screw (DHS) or proximal femoral nail (PFN) fixation techniques. Material and methodsThis prospective, randomised, blinded trial included patients aged over 65 years with intertrochanteric fractures classified as AO group 31.A1 or 31.A2. The patients were allocated into one of two treatment groups: one treated with DHS and the other with PFN. Data on functional recovery were obtained using the Functional Recovery Score developed by Zuckerman for elderly patients with hip fracture. Variables were described as means and standard deviations, and the non-parametric Kolmogorov–Smirnov test was used to verify the normality of data distribution. Non-normally distributed variables were compared using the non-parametric Friedman and Mann–Whitney U tests. Data processing and analysis were carried out in SPSS 10.0. Results were deemed significant at the 5% level (p≤0.05). ResultsThere were no significant between-group differences in age (p=0.152), sex (p=0.363), or American Society of Anaesthesiologists (ASA) score (p=0.579). Functional recovery scores in the DHS group at 3 and 6 months after surgery were significantly reduced from preoperative baseline scores (p=0.007) compared with in the PFN group. However, there were no statistically significant differences between the two groups in functional recovery scores at baseline (p=0.346) or at 3 months (p=0.880), 6 months (p=0.699), and 12 months (p=0.468) after surgery. There was no between-group difference in mortality (p=0.140). ConclusionAt 1-year follow-up, functional recovery scores were similar in elderly patients treated with the DHS and PFN techniques. However, DHS-treated patients exhibited significant loss of function in the first 6 months after surgery, which did not occur in the PFN-treated group.

A Comparison of Early Clinical and Radiographic Complications of Iliac Screw Fixation versus S2 Alar Iliac (S2AI) Fixation in the Adult and Pediatric Populations

Study Design:Retrospective chart review.Objective:To compare short-term clinical and radiographic complications between iliac screw (IS) and S2 alar-iliac (S2AI) screw fixation techniques in the adult and pediatric populations.Summary of Background Data:Pelvic fixation with lumbosacral implants is i

Treatment of tibial eminence fractures: a systematic review.

Fractures of the tibial eminence are rare, accounting for less than 1% of the injuries involving the anterior cruciate ligament (ACL). Most agree that nondisplaced fractures can be managed nonoperatively, but debate exists over the ideal treatment of displaced fractures. This systematic review evaluates the outcome of nonoperatively and operatively managed displaced tibial eminence fractures. The PubMed, Embase, and Cochrane databases were queried. Inclusion criteria included reported outcomes of displaced tibial eminence fractures, minimum 2-year follow-up, and English language. Outcomes reported were pooled and included the following: clinical instability (Lachman/anterior drawer, pivot shift, and KT 1000), patient-reported pain and/or instability, return to sport, Lysholm, Tegner, and the need for ACL reconstruction. Comparison was made in the outcomes of nonoperatively and operatively treated fractures and between suture and screw fixation techniques. Overall 16 studies met the inclusion criteria. The pooled mean age was 23 years and mean follow-up was 35 months. Clinical instability was seen in 70% of nonoperatively treated patients and 14% of operatively treated patients (p < 0.0001). Patient-reported instability was higher in nonoperatively treated patients (54 vs. 1.2%, p < 0.0001), as was the rate of ACL reconstruction (10 vs. 1.0%, p = 0.036). In comparing suture fixation to screw fixation, patient-reported instability and the rate of ACL reconstruction were equivalent. Patients treated with screw fixation had a higher incidence of clinically measured instability (Lachman and KT arthrometer) and an increased rate of hardware removal (3.9 vs. 64.9%, p < 0.05). Surgically managed patients report less instability, are higher functioning, and require fewer ACL reconstructions when compared with nonoperatively treated patients. Suture fixation was associated with improvements in clinical measures of stability and decreased need for hardware removal; however, patient perception of stability and need for ACL reconstruction was no different between the two treatment methods.

Four lateral mass screw fixation techniques in lower cervical spine following laminectomy: a finite element analysis study of stress distribution.

BackgroundLateral mass screw fixation (LSF) techniques have been widely used for reconstructing and stabilizing the cervical spine; however, complications may result depending on the choice of surgeon. There are only a few reports related to LSF applications, even though fracture fixation has become a severe complication. This study establishes the three-dimensional finite element model of the lower cervical spine, and compares the stress distribution of the four LSF techniques (Magerl, Roy-Camille, Anderson, and An), following laminectomy -- to explore the risks of rupture after fixation.MethodCT scans were performed on a healthy adult female volunteer, and Digital imaging and communication in medicine (Dicom) data was obtained. Mimics 10.01, Geomagic Studio 12.0, Solidworks 2012, HyperMesh 10.1 and Abaqus 6.12 software programs were used to establish the intact model of the lower cervical spines (C3-C7), a postoperative model after laminectomy, and a reconstructive model after applying the LSF techniques. A compressive preload of 74 N combined with a pure moment of 1.8 Nm was applied to the intact and reconstructive model, simulating normal flexion, extension, lateral bending, and axial rotation. The stress distribution of the four LSF techniques was compared by analyzing the maximum von Mises stress.ResultThe three-dimensional finite element model of the intact C3-C7 vertebrae was successfully established. This model consists of 503,911 elements and 93,390 nodes. During flexion, extension, lateral bending, and axial rotation modes, the intact model’s angular intersegmental range of motion was in good agreement with the results reported from the literature. The postoperative model after the three-segment laminectomy and the reconstructive model after applying the four LSF techniques were established based on the validated intact model. The stress distribution for the Magerl and Roy-Camille groups were more dispersive, and the maximum von Mises stress levels were lower than the other two groups in various conditions.ConclusionThe LSF techniques of Magerl and Roy-Camille are safer methods for stabilizing the lower cervical spine. Therefore, these methods potentially have a lower risk of fixation fracture.

Treatment of unstable thoracolumbar fractures through short segment pedicle screw fixation techniques using pedicle fixation at the level of the fracture: a finite element analysis.

ObjectiveTo compare the von Mises stresses of the internal fixation devices among different short segment pedicle screw fixation techniques to treat thoracic 12 vertebral fractures, especially the mono-segment pedicle screw fixation and intermediate unilateral pedicle screw fixation techniques.MethodsFinite element methods were utilised to investigate the biomechanical comparison of the four posterior short segment pedicle screw fixation techniques (S4+2: traditional short-segment 4 pedicle screw fixation [SPSF]; M4+2: mono-segment pedicle screw fixation; I6+2: intermediate bilateral pedicle screw fixation; and I5+2: intermediate unilateral pedicle screw fixation).ResultsThe range of motion (ROM) in flexion, axial rotation, and lateral bending was the smallest in the I6+2 fixation model, followed by the I5+2 and S4+2 fixation models, but lateral bending was the largest in the M4+2 fixation model. The maximal stress of the upper pedicle screw is larger than the lower pedicle screw in S4+2 and M4+2. The largest maximal von Mises stress was observed in the upper pedicle screw in the S4+2 and M4+2 fixation models and in the lower pedicle screw in the I6+2 and I5+2 fixation models. The values of the largest maximal von Mises stress of the pedicle screws and rods during all states of motion were 263.1 MPa and 304.5 MPa in the S4+2 fixation model, 291.6 MPa and 340.5 MPa in the M4+2 fixation model, 182.9 MPa and 263.2 MPa in the I6+2 fixation model, and 269.3 MPa and 383.7 MPa in the I5+2 fixation model, respectively. Comparing the stress between different spinal loadings, the maximal von Mises stress of the implants were observed in flexion in all implanted models.ConclusionAdditional bilateral pedicle screws at the level of the fracture to SPSF may result in a stiffer construct and less von Mises stress for pedicle screws and rods. The largest maximal von Mises stress of the pedicle screws during all states of motion were observed in the mono-segment pedicle screw fixation technique.

Radiographic and clinical assessment of a freehand lateral mass screw fixation technique: is it always safe in subaxial cervical spine?

Background contextMany spine surgeons use the freehand technique for lateral mass (LM) screw fixation. However, issues about its safety still exist. PurposeTo examine the safety of the freehand technique after LM screw insertion. Study designRetrospective case series. Patient sampleA total of 26 patients (21 men and five women) who underwent LM screw fixation via the freehand technique were included. Outcome measuresPostoperative computed tomography images and medical records were analyzed. MethodsDuring surgery, the lateral trajectory of screws was set using the adjacent spinous process (SP) after the cranial trajectory was set by palpating the joint surface. Computed tomography analyses were performed for the measurement of screw angles, and axial images were evaluated to determine the SP length that would be long enough to not involve the transverse foramen. The medical records were evaluated for the investigation of surgery-related complications. ResultsEach axial and sagittal angle of the screws showed a significant difference. A total of 18 screws (13.5%) involved the transverse foramen, and the mean axial angle of the screws was significantly smaller than the group not involving the foramen (p=.0078). A total of eight screws (6.0%) violated the facet, and the mean sagittal angle was significantly smaller than the group not violating the facet. The average difference in angles between the screw and the actual joint surface was largest at C6 (p=.0472). The mean maximum length of the SP, long enough to not involve the transverse foramen was significantly short at C3 and C6 (p=.0015). The actual SP length in one patient was longer than the maximum SP length determined through analysis in the case of C6. If the SP of C7 was used in C6, the SP length would not be safe in six patients. ConclusionsExcellent outcomes were observed with the use of the freehand technique for the insertion of LM screw at the subaxial C spine. However, this technique using the SP may pose a relative risk at C6.

Can Radiation Exposure to the Surgeon Be Reduced With Freehand Pedicle Screw Fixation Technique in Pediatric Spinal Deformity Correction? A Prospective Multicenter Study

Prospective multicenter study of patients who underwent pediatric spinal deformity correction with posterior spinal fusion and instrumentation. To quantify radiation exposure to the surgeon during pedicle screw fixation using the freehand technique in pediatric spinal deformity surgery. Pedicle screw placement in thoracic and lumbar spine for spinal deformity is technically demanding and involves radiation exposure. Many experienced spinals surgeons use the freehand technique for pedicle screw fixation in spinal deformity surgery. There are no studies analyzing radiation exposure to the surgeon regarding freehand pedicle screw fixation technique. A prospective multicenter study was designed to evaluate radiation exposure to the operating spinal surgeon who uses the freehand pedicle screw fixation technique in pediatric spinal deformity correction. All of the operating surgeons placed a gamma radiation dosimeter on their chest outside the lead apron during surgery. Surgeons placed pedicle screws in the pediatric spinal deformity using the freehand technique. We included patients who had undergone correction with posterior spinal fusion and instrumentation with all pedicle screw constructs in this study. We analyzed 125 patients with pediatric spinal deformity who were operated on between 2008 and 2012. The average fluoroscopic time was 40.5 ± 21 seconds. The overall average fluoroscopic time for placement of a single pedicle screw and per fixation level were 2.6 ± 1.7 seconds and 3.9 ± 2.5 seconds, respectively. In each surgery, the recorded radiation exposure to the surgeon was less than the minimum reportable dose (<0.010 mSv) with an average of 0.0005 ± 0.00013 mSv per surgery. The use of freehand technique for pedicle screw fixation in spinal deformity correction requires a minimum amount of fluoroscopic use, hence decreasing radiation exposure to the surgeon and patient. 4.

Biomechanics of lateral lumbar interbody fusion constructs with lateral and posterior plate fixation

Lumbar interbody fusion is indicated in the treatment of degenerative conditions. Laterally inserted interbody cages significantly decrease range of motion (ROM) compared with other cages. Supplemental fixation options such as lateral plates or spinous process plates have been shown to provide stability and to reduce morbidity. The authors of the current study investigate the in vitro stability of the interbody cage with a combination of lateral and spinous process plate fixation and compare this method to the established bilateral pedicle screw fixation technique. Ten L1-5 specimens were evaluated using multidirectional nondestructive moments (± 7.5 N · m), with a custom 6 degrees-of-freedom spine simulator. Intervertebral motions (ROM) were measured optoelectronically. Each spine was evaluated under the following conditions at the L3-4 level: intact; interbody cage alone (stand-alone); cage supplemented with lateral plate; cage supplemented with ipsilateral pedicle screws; cage supplemented with bilateral pedicle screws; cage supplemented with spinous process plate; and cage supplemented with a combination of lateral plate and spinous process plate. Intervertebral rotations were calculated, and ROM data were normalized to the intact ROM data. The stand-alone laterally inserted interbody cage significantly reduced ROM with respect to the intact state in flexion-extension (31.6% intact ROM, p < 0.001), lateral bending (32.5%, p < 0.001), and axial rotation (69.4%, p = 0.002). Compared with the stand-alone condition, addition of a lateral plate to the interbody cage did not significantly alter the ROM in flexion-extension (p = 0.904); however, it was significantly decreased in lateral bending and axial rotation (p < 0.001). The cage supplemented with a lateral plate was not statistically different from bilateral pedicle screws in lateral bending (p = 0.579). Supplemental fixation using a spinous process plate was not significantly different from bilateral pedicle screws in flexion-extension (p = 0.476). The combination of lateral plate and spinous process plate was not statistically different from the cage supplemented with bilateral pedicle screws in all the loading modes (p ≥ 0.365). A combination of lateral and spinous process plate fixation to supplement a laterally inserted interbody cage helps achieve rigidity in all motion planes similar to that achieved with bilateral pedicle screws.

Predictive factors for a kyphosis recurrence following short-segment pedicle screw fixation including fractured vertebral body in unstable thoracolumbar burst fractures.

ObjectiveThe technique of short segment pedicle screw fixation (SSPSF) has been widely used for stabilization in thoracolumbar burst fractures (TLBFs), but some studies reported high rate of kyphosis recurrence or hardware failure. This study was to evaluate the results of SSPSF including fractured level and to find the risk factors concerned with the kyphosis recurrence in TLBFs.MethodsThis study included 42 patients, including 25 males and 17 females, who underwent SSPSF for stabilization of TLBFs between January 2003 and December 2010. For radiologic assessments, Cobb angle (CA), vertebral wedge angle (VWA), vertebral body compression ratio (VBCR), and difference between VWA and Cobb angle (DbVC) were measured. The relationships between kyphosis recurrence and radiologic parameters or demographic features were investigated. Frankel classification and low back outcome score (LBOS) were used for assessment of clinical outcomes.ResultsThe mean follow-up period was 38.6 months. CA, VWA, and VBCR were improved after SSPSF, and these parameters were well maintained at the final follow-up with minimal degree of correction loss. Kyphosis recurrence showed a significant increase in patients with Denis burst type A, load-sharing classification (LSC) score >6 or DbVC >6 (p<0.05). There were no patients who worsened to clinical outcome, and there was no significant correlation between kyphosis recurrence and clinical outcome in this series.ConclusionSSPSF including the fractured vertebra is an effective surgical method for restoration and maintenance of vertebral column stability in TLBFs. However, kyphosis recurrence was significantly associated with Denis burst type A fracture, LSC score >6, or DbVC >6.

Humeral Head Reconstruction for Hill-Sachs Defects: A Biomechanical Comparison of 2 Fixation Techniques for Bone Grafting

The purpose of this biomechanical study was to compare anterograde with retrograde screw fixation for allograft reconstruction of Hill-Sachs defects. In 8 pairs of fresh-frozen humeral heads, a 40% Hill-Sachs defect was created. The resultant wedge-shaped osteochondral fragment was used as allograft. For each technique, two 3.75-mm screws were used for fixation. To test the strength of fixation, a custom tool was used that would apply load to the graft. By use of a materials testing machine, a staircase cyclic loading protocol was performed (500 cycles at 10, 20, 30, and 40 N) and then load to failure. Graft displacement was measured by an optical tracking system. For the 2 techniques, graft displacement increased with increasing load and increasing number of cycles up to a mean of 0.9 ± 0.42 mm for anterograde fixation and 1.1 ± 0.79 mm for retrograde fixation. This increase was significant within each technique across all 4 loading levels (P < .05). However, there were no significant differences in graft displacement between the 2 techniques at any loading level or number of cycles (P = .16 to P = .96). In addition, the load to failure between the anterograde and retrograde techniques (98.5 N and 95.6 N, respectively) was not significantly different (P = .706). The initial fixation and failure strength of anterograde and retrograde graft fixation techniques for substantial Hill-Sachs defects do not significantly differ in a biomechanical cadaveric model. This biomechanical study supports that in an engaging Hill-Sachs defect, both anterograde and retrograde screw fixation techniques can be used for fixation of humeral head allografts.

Evaluation and Treatment Recommendations for Acute Injuries to the Ankle Syndesmosis Without Associated Fracture

Ankle ligamentous injuries are commonly seen in athletes in a variety of sports. Surveys of physicians and trainers of professional sports teams have identified syndesmotic injuries as among the most difficult to treat. In particular, injuries of the ankle syndesmosis have been strongly linked with a prolonged recovery and increased time to return to play. Due to sudden external rotation with the tibiotalar joint in dorsiflexion, these structures are commonly injured in association with fractures of the distal fibula. Surgery is indicated in cases with associated fractures and ligamentous instability, but optimal treatment for syndesmosis injuries without an associated fracture is less clear. A thorough history and physical examination, as well as appropriate imaging, are necessary to effectively diagnose and classify the injury. For stable injuries, short-term immobilization and functional rehabilitation is recommended. Unstable Grade 2 and 3 injuries require surgical fixation. Debate currently exists over rigid screw fixation versus suture button techniques as the ideal fixation method.

A minimally invasive sinus tarsi approach with percutaneous plate and screw fixation for intra-articular calcaneal fractures

According to characteristic of anatomical structure of calcaneus and sinus tarsi approach, the minimally invasive plate for treatment of displaced intra-articular calcaneal fractures had been designed. Here we aimed to review the effect of this treatment. Forty intra-articular calcaneal fractures in 38 patients from September 2006 to September 2008 were treated with percutaneous plate via sinus tarsi approach under the monitoring of C-shaped arms. All calcaneal anatomical parameters, including height, width, length, Böhlers angle and Gissane angle were measured by X-ray before and after surgery. Postoperative lateral wound healing was also evaluated and clinical functional outcomes were graded using the Maryland foot score. All patients had been followed up for an average of 12 months ranged from 3 months to 24 months. X-ray indicated satisfactory restoration of the calcaneal height, width, length, Böhlers angle and Gissanes angle. Maryland foot score demonstrated that excellent result was achieved in 32 cases, good in 6 cases, fair in 2 cases, and the excellent and good rate was 95%. Postoperative complications were not found in all fractured feet. Our results suggest that this minimally invasive sinus tarsi approach with new designed plate and screw fixation technique for the treatment of intra-articular calcaneal fractures can not only obtain the satisfactory outcomes, but also can effectively prevent surgical complications.

The posterior approach combined with pedicle screw fixation for the treatment of lower cervical fractures and dislocation

Objective To evaluate the feasibility of using the posterior approach with cervical pedicle screw fixation technique for the treatment of lower cervical spine fractures and dislocations.Methods Thirty patients suffered lower cervical fractures and dislocations were retrospectively analyzed,and they were underwent cervical pedicle screw system fixation surgery from January 2010 to December 2012.There were 22 males and 8 females,with an average age of 41 years (range,24-61 years).Eight injuries were located at C4,5,12 at C5,6,and 10 at C6.7.According to the American Spinal Cord Injury Association (ASIA)impairment scale,8 cases were grade A,12 were grade B,5 were grade C,3 were grade D,and 2 were grade E.Results Reduction and fixation of the injured segments were performed via a posterior approach in all 30 patients.One hundred and forty pedicle screws were inserted successfully in all patients on the postoperative radiographic and CT scans.All the patients were followed up for 3-23 months,with the average of 11 months.According to the ASIA impairment scale,eight cases with grade A were still grade A,but the feeling and movement improved obviously.Ten grade B improved to grade C and the rest cases were complete recovery after operations.During the course of the follow up,solid bone union was achieved in all patients,and there were no hardware failures.All the patients' postoperative MRI showed disappearance of the spinal cord compression after reduction in all cases.Conclusion For the patients of lower cervical fractures and dislocation,the first choice of operation should be the posterior approach reduction and fixation with cervical pedicle screw.The correct lengthwise traction method could unblock the locked facet effectively,and prevent the retrusion of disc and the further injury of spinal cord.For the patients of disc disruption,the posterior approach could be used only.The cervical pedicle screw system could provide three-dimensional reduction of the injured cervical segments and the adequate mechanical strength.The posterior approach combined with pedicle screw fixation is feasible and effective for the treatment of lower cervical fractures and dislocation. Key words: Cervical vertebrae; Fractures bone; Spinal cord injuries; Fracture fixation, internal