Aims. Anchorage of pedicle screw rod instrumentation in the elderly spine with poor bone quality remains challenging. Our study aims to evaluate how the screw bone anchorage is affected by screw design, bone quality, loading conditions, and cementing techniques. Methods. Micro-finite element (µFE) models were created from micro-CT (μCT) scans of vertebrae implanted with two types of pedicle screws (L: Ennovate and R: S. 4. ). Simulations were conducted for a 10 mm radius region of interest (ROI) around each screw and for a full vertebra (FV) where different cementing scenarios were simulated around the screw tips. Stiffness was calculated in pull-out and anterior bending loads. Results. Experimental pull-out strengths were excellently correlated to the µFE pull-out stiffness of the ROI (R. 2. > 0.87) and FV (R. 2. > 0.84) models. No significant difference due to screw design was observed. Cement augmentation increased pull-out stiffness by up to 94% and 48% for L and R screws, respectively, but only increased bending stiffness by up to 6.9% and 1.5%, respectively. Cementing involving only one screw tip resulted in lower stiffness increases in all tested screw designs and loading cases. The stiffening effect of cement augmentation on pull-out and bending stiffness was strongly and negatively correlated to local bone density around the screw (correlation coefficient (R) = -0.95). Conclusion. This combined experimental, µCT and µFE study showed that regional analyses may be sufficient to predict fixation strength in pull-out and that full analyses could show that cement augmentation around pedicle screws increased fixation stiffness in both pull-out and bending, especially for low-density bone. Cite this article: Bone Joint Res 2021;10(12):797–806

Objectives. This presentation discusses the experience at our Centre with treating traumatic thoracolumbar fractures using percutaneous pedicle screw fixation and also looks at clinical and radiological outcomes as well as complications. Design. This is a retrospective study reviewing all cases performed between Jan 2013 and June 2019. Subjects. In our study there were 257 patients in total, of which there were 123 males and 134 females aged between 17 and 70. Methods. We reviewed the case notes and imaging retrospectively to obtain the relevant data. Results. A total of 257 patients were included, 123 males and 134 females; the mean age was 47.6 years. The majority of injuries were from fall from significant height. In 98 cases the fracture involved a thoracic vertebra and in 159 cases a lumbar vertebra. Percutaneous pedicle screw fixation was performed either one level above and below fracture or Two levels above and below the fracture depending upon the level of injury. Forty two cases were treated with additional short pedicle screws at the level of fracture. More than 15% (39) of patients presented with a neurological deficit on admission and more than 80% (32) of those showed post-operative improvement in their neurology as per Frankel Grading system. The mean Operative time was 117minutes +− 45, and mean length of hospital stay was 7.2 +− 3.8 days, with significant improvement in Visual analogue score. Percutaneous fixation achieved a satisfactory improvement in radiological parameters including sagittal Cobb angle (SCA) post-operatively in all patients. The vast majority of patients achieved a good functional outcome according to modified Macnab criteria. Follow up was for a maximum of two years, with relevant imaging at each stage. Ten (3.8%) patients had wound infection with three patients requiring wound debridement. Four patients had upper level screws pulled out and in Four cases one screw was misplaced. All eight had revision surgery. Conclusions. Percutaneous pedicle screw fixation is a safe surgical option with comparable outcomes to open surgery and a potential reduction in perioperative morbidity. Percutaneous pedicle screw fixation is the primary surgical technique to treat traumatic thoracolumbar fractures at our Centre. There were no major complications in our series, with good functional outcome following surgery

Purposes: To evaluate the validity of pedicle screw fixation in 20 patients with toracolumbar spine infections. Methods and Materials: There were seven tuberculous and thirteen pyogenic infection, eight had thoracic and 12 had lumbar lesion. The indications for surgical treatment were; progressive bone destruction, mal-alignment or neurological deficit. On nine cases, we did two-step operation, which was bone graft from anterior and pedicle screw fixation from posterior. On 11 cases, we did debridement, interbody graft and the pedicle screw fixation from posterior simultaneously. We examined the outcomes of the infection, symptoms including neurological deficit and the graft bones postoperatively with follow-up period of 25 months in the average. We also examined changes of alignment after surgery and surgical complications as well to evaluate the validity of the surgery. Results: Fusion of graft were confirmed in all cases within seven and half months in the average. Clinically, all of 14 patients who had had paraparesis gained neurological recovery of one or two steps of Frankel’s criteria after the surgery. Complications were, fracture of graft, fracture of vertebral body, screw loosening with alignment deterioration and recurrence of infection in one case each. Summary: Pedicle screw fixation revealed a usefulness in surgical treatment of spine infection

Objective. The use of all pedicle screw constructs for the management of spinal deformities has gained widespread popularity. However, the placement of pedicle screws in the deformed spine poses unique challenges for the spinal surgeon. The purpose of this study was to evaluate the complications and radiological outcomes of surgery in 124 consecutive patients with spinal deformity. These patients underwent correction of coronal and sagittal imbalance with segmental pedicle screw fixation only. Background. All pedicle screw constructs have been associated with improved correction in all three planes. In patients with severe deformity, such constructs can obviate the need for anterior surgeries, and the higher implant cost is offset by the avoidance of dual anterior and posterior approaches. Pedicle screw fixation enables enhanced correction of spinal deformities, but the technique is still not widely applied for thoracic deformities for fear of neurological complications. This is a retrospective study that was carried out on 124 patients who underwent segmental screw fixation for coronal and sagittal spinal deformities. The purpose of this study was to evaluate the complications and outcomes of this technique and also assess the evidence of enhanced correction. Material and Methods. A total of 124 consecutive patients subjected to pedicle screw fixation for spinal deformities were analysed after a minimum period of follow-up of two years. Etiologic diagnoses were idiopathic scoliosis in 32, neuromuscular scoliosis 48, Scheuermann's kyphosis in 28 and others 16. They were reviewed using the medical records and preoperative, intraoperative and postoperative radiographs. Computed tomography was performed when screw position was questionable. Deformity correction was determined on preoperative and postoperative radiographs. The positions of the screws were evaluated using intraoperative and postoperative radiographs. There were 51 male and 73 female patients with the mean age of 17.2 years (range, 10-25 years). The average cobb angle for scoliosis and kyphosis were 55°(range 45°-85°) and 72° (range 68°-100°) respectively. Results. A total of 2784 pedicle screws were inserted and 1488 screws were inserted in the thoracic spine (18 screws/patient). Screw-related neurological complications occurred in two patients 0.4%; these comprised a transient paraparesis and dural tear. Other complications comprised six intraoperative pedicle fractures, 12 screw loosening, four postoperative infections and one haemothorax. There were no significant screw-related neurological or visceral complications. The average correction was 78% for scoliosis and 51% for kyphosis. The mean estimated blood loss was 653 ml (range, 510-850), the mean operation time was 148 minutes (range, 120-220). Conclusion. We were able to demonstrate that application of pedicle screw construct is safe and advantageous in the management of spinal deformities. Significant correction has been achieved with a single stage posterior surgery in all groups. Scoliosis and kyphotic deformity corrections were 78% and 51% respectively; this is far superior to correction achieved with one stage surgery with other constructs. This study showed that improved derotation has decreased the need for thoracoplasty, thus eliminating its risk of associated morbidity. Superior control of the deformity obviated the need for an anterior approach in severe curves. Improved correction, lower morbidity and shorter hospitalisation has compensated for higher implant cost. We believe using all pedicle screw fixation is a relatively safe procedure and offers an excellent correction. This correction was maintained throughout the follow up period. Despite our safety record in thoracic pedicle screw placement, we believe this technique can be potentially dangerous in inexperienced hands, and requires a long learning curve. Therefore, a thorough anatomical knowledge of pedicle morphology, a detailed analysis of pre-operative imaging coupled with experience is essential to avoid complications. Ethics approval None. Interest Statement None

A prospective cohort outcome evaluation of unstable thoracic spine fractures treated with posterior pedicle screw fixation. The purpose of this study was to determine the accuracy of placement and safety of pedicle screws in open reduction of unstable thoracic spine fractures. The surgeries were performed by one of five fellowship trained spinal surgeons. CT scans were formed on twenty-three patients totaling two hundred screws using 3mm cuts. Three independent reviewers assessed and categorized the screw position as within the pedicle or as a violation of the pedicle wall. 98% of the screws were accurate and we recommend the use of pedicle screws in thoracic fractures . A prospective cohort outcome evaluation of unstable thoracic spine fractures treated with posterior pedicle screw fixation. This study is to determine the accuracy of placement, safety of pedicle screws in open reduction of unstable thoracic spine fracture. Surgery was performed by one of five fellowship trained spine surgeons. CT scans were performed on twenty-three patients using 3mm cuts in both sagittal and transverse planes. Pedicle screw position was assessed by three independent reviewers. Screw position was categorized as within the wall of the pedicle or in violation of the wall. Further sub-classification of pedicle wall violation reviewed the direction and distance of perforation. Independent perioperative and postoperative surveillance for complications was done. Twenty-three unstable thoracic spine fractures treated with two hundred posterior pedicle screws were analyzed. The pedicle screws spanned from T1-T12 with the majority of screws in the mid-thoracic region. Of the two hundred thoracic pedicle screws placed, 70% were fully contained within the pedicle wall. The remaining screws were deemed “out” with cortical perforation (30%). Of these, 20% were lateral perforations, 5% were medial perforations and 5% were anterolateral perforations. No superior, inferior, or anteromedial perforations were found. There was no regional area variation in incidence of perforations. 10% of all perforations were directly related to pedicle diameter to screw diameter mismatch. There were no adverse neurological, vascular, or visceral injuries detected intraoperatively or postoperatively. Surgical management of unstable thoracic spine fractures with posterior pedicle screw fixation is safe. 98% of screws had satisfactory accuracy. Although very minor misplacement of pedicle screws occurred, there were no complications and we recommend the use of pedicle screws in thoracic fractures

The evaluation of early results of combined percutaneous pedicle screw fixation and kyphoplasty for the management of thoraco-lumbar burst fractures. Between October 2008 and April 2009, 9 patients with thoracolumbar burst fractures underwent percutaneous short-segment pedicle screw fixation and augmentation kyphoplasty with calcium phosphate cement. All patients were selected according to the type of fracture (unstable type A3 fractures based on the Magerl classification) the absence of neurological signs and an intact posterior longitudinal ligament on the pre-operative MRI scan. Patient demographics, co-morbidities and complications were recorded. The main endpoints included Cobb angle correction, vertebral body height restoration and the length of hospital stay. There were 3 male and 6 female patients with an average age of 43.6 years. The average follow-up was 2.4 months. The mean kyphotic angulation improved from 18.40 pre-operatively to 6, 80 post-operatively. The loss of vertebral body height improved from a mean of 38.7 % pre-operatively to 12.1 % post-operatively. The average duration of surgery was 40 minutes with insignificant blood loss. There were no post-operative complications. The average length of hospital stay was 3.2 days. The combination of percutaneous short-segment pedicle screw fixation supplemented by balloon kypho-plasty for the management of thoracolumbar burst fractures with no neurological deficit offers correction of the normal thoracolumbar anatomy as well as augmentation of the anterior load-bearing column, using a minimally invasive technique. The early results are promising

The success of lumbar spine fusion depends on good patient selection and bone grafting technique. Instrumentation of the fusion, now popular, improves fusion rates, eliminates the need for postoperative braces and allows early mobilisation. However, the stress shielding caused by rigid internal fixation is thought to lead to osteopoenia and degeneration of adjacent segments. Theatre times, intra-operative complications and costs are increased when pedicle screw fixation is added. This is a report of a pilot study of eight patients who had one-level fusion and unilateral instrumentation between 1998 and 2000. Theatre time, fusion rate and functional outcomes were evaluated. The minimum follow-up time was eight months. Fusion was achieved in all patients and there was no metal failure. One patient continued to have back and leg pain in spite of a solid fusion. Although this is a small study undertaken over a short period, the results suggest that unilateral pedicle screw fixation can be safely undertaken

Aiming to evaluate the efficacy and safety of instrumentation using only segmental pedicle screw fixation, we undertook a prospective study of 17 patients with idiopathic scoliosis who underwent corrective surgery in 1998 and 1999. A total of 170 pedicle screws was inserted, 119 in the thoracic spine and 51 in the lumbar, extending from T2 to L5. The Cobb angle was measured on an erect anteroposterior radiograph postoperatively and at 6 and 12-month follow-up. Pedicle screw placement was assessed on the radiographs, and where there was concern about screw position, CT scan was performed. Of the 170 pedicle screws, three were malpositioned lateral to the pedicle and one medial to the pedicle. One pedicle fractured during screw insertion, and three screws partially pulled out on the convex side of the curve at T3 to T5. At six months the mean Cobb angle correction was 53.6%. There were no neurological complications. Two cases required subsequent trimming of rods. We believe fixation using only segmental pedicle screws is a safe method of correcting idiopathic scholastic deformities, but retain some reservations about the pull-out strength of the uppermost screws in the thoracic spine

Minimally invasive (MIS) screw fixation for Hangman's fracture can decrease iatrogenic soft-tissue injury compared with conventional open approach, but increase the risk of instrumentation-related complications due to lack of anatomical landmarks. With the advantages, the intra-operative three-dimensional fluoroscopy-based navigation (ITFN) system seems to be an inherent partner for MIS techniques. The purpose of this study was to evaluate the accuracy and feasibility of MIS techniques incorporating with ITFN for treating Hangman's fracture. 20 patients with Hangman's fracture underwent C2-C3 pedicle screw fixation using ITFN. 6 patients used MIS technique, with the other 14 patients using conventional open technique. Preoperative visual analogue score (VAS) was 5.7±1.4 in CAOS-MIS group and 5.5±0.9 in CAOS-open group. Operative time, blood loss and postoperative neurovascular complications were recorded. The accuracy of screw positions was studied by postoperative CT scan. All patients were followed up for at least 6 months and the fusion status was ascertained by dynamic radiographs. The average operative time was 134.2±8.0 min in CAOS-MIS group and 139.3±25.8 min in CAOS-open group, and there was no significant difference between the two (p>0.01). The blood loss was 66.7±25.8 ml in CAOS-MIS group and 250.0±141.4 ml in CAOS-open group. Statistical difference existed with CAOS-MIS group significant less than CAOS-open group (p<0.01). A total of 80 screws were inserted. No screw-related neurovascular injury was observed. Post-operative CT scan revealed 83.3% (20/24) screws of grade 1 and 16.7% screws of grade 2 (4/24) in CAOS-MIS group, meanwhile 89.3% screws of grade 1 (50/56) and 10.7% screws of grade 2 (6/56) in CAOS-open group. There was no grade 3 screw detected. Fisher's exact test showed there was no statistical difference between these two groups (p>0.01). There was no statistical difference in pre-operative VAS between these two groups (p>0.01). Compared with the CAOS-open group (1.7±0.6), neck pain VAS at 6-month follow-up in CAOS-MIS group (0.3±0.5) was significantly lower (p<0.01). Solid fusion was demonstrated in all the cases by dynamic radiographs. So it is feasible and safe for percutaneous minimally invasive C2-C3 pedicle screw fixation for Hangman's fracture using intra-operative three-dimensional fluoroscopy-based navigation, which can also decrease the incidence of post-operative neck pain

Introduction: The management of thoraco-lumbar burst fractures remains controversial. Different authors have advocated immobilisation, external bracing or internal fixation by either anterior or posterior approaches. Advocates of posterior fixation have in general performed stabilisation one level above and one level below the site of the fracture, resulting in fixation of two motion segments. It is known that multi-segmental spinal fusion produces undesirable biomechanics. To stabilise the site of the fracture and avoid unnecessary fixation of an uninjured segment the senior author (T.S.) for selected patients has been using a novel technique of monosegmental fixation with placement of pedicle screws directly into the fractured vertebral body. Methods: All patients with thoraco-lumbar burst fractures admitted to St Vincents and Concord Hospitals between January 2001 and October 2003 were considered for monosegmental fixation. Patients with severe osteoporosis or complete loss of vertebral body height (“vertebra plana”) were excluded. All patients underwent surgical decompression and fixation within 10 days of injury. Fixation was obtained with 4 titanium pedicle screws and a single transverse connector (Xia System Stryker Spine). Reduction of kyphotic deformity was carried out in selected patients. Average blood loss for the procedure was 250 ml with no patients requiring transfusion. All patients had a minimum of 6 months radiological and clinical follow-up. Results: Since January 2001, 18 patients with thoracolumbar burst fractures (T10-L2) were treated with single-level pedicle screw fixation. All patients were mobilised within 10 days of surgery. One patient experienced a minor superficial wound infection. There were no other postoperative complications. All patients had a stable fusion construct at 6 weeks following surgery. No patient experienced neurological deficit or have developed a delayed kyphotic deformity. There were no instances of instrument failure. 17 out of 18 patients report no significant back pain with any limitation of function by three months following surgery. One patient reports mild mechanical lower back pain 12 months following the injury. Discussion: Single level fixation for selected cases of thoracolumbar burst fracture is a safe and effective procedure to decompress the neural elements and obtain fixation and fusion of the fractured segment. It allows for rapid mobilisation and avoids a two-level fusion procedure with its subsequent detrimental effect on spinal biomechanics. It is considerably less invasive than anterior/lateral approaches which require extensive muscle dissection, rib removal and even diaphragmatic division

Introduction. We report the outcomes of minimally invasive technique for posterior lumbar interbody fusion (PLIF) procedure using Hollow Modular Anchorage (HMA) screws supplemented by routine pedicle screw fixation (Dynesis). Patients and Methods. Seventy-nine patients, who had undergone PLIF procedure using HMA screws supplemented by pedicle screw fixation, were included. Patients deemed suitable for surgery following discography under sedation, with Marcaine instillation establishing reducibility of the listhesis and temporary relief of symptoms. Clinical outcome included visual analogue scale scores for leg pain and back pain, Oswestry Disability Index (ODI) and SF-36 questionnaires. Results. Average age was 59 (range: 27-85). Mean follow- up was 5 years (range: 1-10). All cases went into union. None were lost to follow-up. Average length of stay was 24 hours (18-72 hours). All clinical parameters improved except SF-36. Mean ODI improved from 54 (range: 44-89) preoperatively to 33 (17-55) postoperatively (statistically significant, p=0.004). Back pain relief improved in visual analogue scale from average of 68 (range: 60-100) preoperatively to 37 postoperatively (range: 8:46) (statistically significant, p= 0.022). Leg pain relief improved from 53 (range: 31-100) preoperatively to 28 postoperatively (range: 4:60) (statistically significant, p= 0.007). Although mean SF-36 score improved from 37 (range: 10-41) preoperatively to 47 (range: 53-94) postoperatively (statistically insignificant, p=0.592). Complications included: one infection required removal of implant; two temporary motor weaknesses related to L5 nerve root; four required removal of the pedicle screw due to pain or loosening. Discussion. Our results are encouraging. Interbody HMA screws are porous hollow titanium screws with favourable biomechanical characteristics. Rather than square cages, they permit accurate placement of implant. Dynesys offers the option of extension and flexible support for the adjacent segment. Conclusion. PLIF supplemented with pedicle fixation is a reliable and safe procedure for degenerative spondylolisthesis. SF-36 is less sensitive for assessing spinal surgery outcome

In patients with osteoporosis there is always a strong possibility that pedicle screws will loosen. This makes it difficult to select the appropriate osteoporotic patient for a spinal fusion. The purpose of this study was to determine the correlation between bone mineral density (BMD) and the magnitude of torque required to insert a pedicle screw. To accomplish this, 181 patients with degenerative disease of the lumbar spine were studied prospectively. Each underwent dual-energy x-ray absorptiometry (DEXA) and intra-operative measurement of the torque required to insert each pedicle screw. The levels of torque generated in patients with osteoporosis and osteopenia were significantly lower than those achieved in normal patients. Positive correlations were observed between BMD and T-value at the instrumented lumbar vertebrae, mean BMD and mean T-value of the lumbar vertebrae, and mean BMD and mean T-value of the proximal femur. The predictive torque (Nm) generated during pedicle screw insertion was [-0.127 + 1.62 × (BMD at the corresponding lumbar vertebrae)], as measured by linear regression analysis. The positive correlation between BMD and the maximum torque required to insert a pedicle screw suggests that pre-operative assessment of BMD may be useful in determining the ultimate strength of fixation of a device, as well as the number of levels that need to be fixed with pedicle screws in patients who are suspected of having osteoporosis.

Introduction

Correction and arthrodesis for cervical kyphosis associated with atetoid cerebral palsy has been considered to be difficult because of their involuntary neck movements and severe deformity. The aim of this study is to evaluate the surgical outcome of midline T-saw laminoplasty and posterior arthrodesis using pedicle screws.

In a prospective observational study we compared the two-year outcome of lumbar fusion by a simple technique using translaminar screws (n = 57) with a more extensive method using transforaminal lumbar interbody fusion and pedicular screw fixation (n = 63) in consecutive patients with degenerative disease of the lumbar spine. Outcome was assessed using the validated multidimensional Core Outcome Measures Index. Blood loss and operating time were significantly lower in the translaminar screw group (p < 0.01). The complication rates were similar in each group (2% to 4%). In all, 91% of the patients returned their questionnaire at two-years. The groups did not differ in Core Outcome Measures Index score reduction, 3.6 (sd 2.5) (translaminar screws) vs 4.0 (sd 2.8) (transforaminal lumbar interbody fusion) (p = 0.39); ‘good’ global outcomes, 78% (translaminar screws) vs 78% (transforaminal lumbar interbody fusion) (p = 0.99) or satisfaction with treatment, 82% (translaminar screws) vs 86% (transforaminal lumbar interbody fusion) (p = 0.52).

The two fusion techniques differed markedly in their extent and the cost of the implants, but were associated with almost identical patient-orientated outcomes.

Extensive three-point stabilisation is not always required to achieve satisfactory patient-orientated results at two years.

Introduction: We have compared the results of pedicle screw (PS) construct only with a hybrid sublaminar wire and pedicle screw construct (HS) in a matched cohort of CP patients, to establish which technique is superior in view of deformity correction and its maintenance.

Methods: 22 male and 14 female CP patients with average age of 16 years (range 8–25 years) underwent surgical correction for spinal deformity. Indications for surgery included loss of sitting balance, progression of spinal deformity, pelvic obliquity and back pain. Group 1 (18 patients) had PS construct only and Group 2 (18 patients) had HS constructs. 32 patients (90%) required sacral fixation. 5 patients in Group 2 required anterior release. All patients had a minimum follow-up of 2 years (range 2–13 years). Clinical and radiographic analyses were performed in both groups.

Results: Mean Cobb angle in Group 1 improved from 650 (range 120–950) to 18.50 (range 0–280) and in Group 2 from 77.60 (range 400–1050) to 34.80 (range 100–620) [p < 0.05]. Mean pelvic obliquity in Group 1 improved from 14.30 (range 00–420) to 2.50 (range 00–50) and in Group 2 from 24.70 (100–510) to 9.70 (range 20–180) [p< 0.05]. Mean surgical time in Group 1 was 224 minutes as compared to 260 minutes in Group 2 [P< 0.05]. 6 patients in Group 2 had proximal junctional kyphosis and implant failure requiring revision. One patient in each group had infection treated with antibiotic therapy.

Conclusions: PS fixation in CP patients, allowed significant correction of large curves without anterior release, eliminated proximal junctional kyphosis and instrumentation failure. Correction of pelvic obliquity was also superior due to three-dimensional corrective force of pedicle screws. Although PS fixation is expensive and technically demanding, it outweighs the costs incurred by two-stage surgery because of its superior durability correction.

Aims

The aim of this study was to systematically compare the safety and accuracy of robot-assisted (RA) technique with conventional freehand with/without fluoroscopy-assisted (CT) pedicle screw insertion for spine disease.

The use of intraoperative navigation and robotic surgery for minimally invasive lumbar fusion has been increasing over the past decade. The aim of this study is to evaluate postoperative clinical outcomes, intraoperative parameters, and accuracy of pedicle screw insertion guided by intraoperative navigation in patients undergoing lumbar interbody fusion for spondylolisthesis. Patients who underwent posterior lumbar fusion interbody using intraoperative 3D navigation since December 2021 were included. Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and Short Form Health Survey-36 (SF-36) were assessed preoperatively and postoperatively at 1, 3, and 6 months. Screw placement accuracy, measured by Gertzbein and Robbins classification, and facet joint infringement, measured by Yson classification, were assessed by intraoperative Cone Beam CT scans performed at the end of instrumentation. Finally, operation time, intraoperative blood loss, hospital stay, and screw insertion time were evaluated. This study involved 50 patients with a mean age of 63.7 years. VAS decreased from 65.8±23 to 20±22 (p<.01). ODI decreased from 35.4%±15 to 11.8%±14 (p<.01). An increase of SF-36 from 51.5±14 to 76±13 (p<.01) was demonstrated. The accuracy of “perfect” and “clinically acceptable” pedicle screw fixation was 89.5% and 98.4%, respectively. Regarding facet violation, 96.8% of the screws were at grade 0. Finally, the average screw insertion time was 4.3±2 min, hospital stay was 4.2±0.8 days, operation time was 205±53 min, and blood loss was 169±107 ml. Finally, a statistically significant correlation of operation time with hospital stay, blood loss and placement time per screw was found. We demonstrated excellent results for accuracy of pedicle screw fixation and violation of facet joints. VAS, ODI and SF-36 showed statistically significant improvements from the control at one month after surgery. Navigation with intraoperative 3D images represents an effective system to improve operative performance in the surgical treatment of spondylolisthesis

Abstract. Objectives. To evaluate the safety and efficacy of vertebroplasty with short segmented cement augmented pedicle screws fixation for severe osteoporotic vertebral compression fractures (OVCF) with posterior/anterior wall fractured patients. Methods. A retrospective study of 24 patients of DGOU type-4 (vertebra plana) OVCF with posterior/anterior wall fracture, were treated by vertebroplasty and short segment PMMA cement augmented pedicle screws fixation. Radiological parameters (kyphosis angle and compression ratio) and clinical parameters Visual analogue scale (VAS) and Oswestry disability index (ODI) were analysed. Results. A significant improvement was noted in VAS (preoperative, 7.90 ± 0.60; final follow-up 2.90 ± 0.54) and ODI (77.10 ± 6.96 to 21.30 ± 6.70), (P < 0.05). Neurological improvement was noted in all patients. Kyphosis corrected significantly from preoperative 23.20 ± 5.90 to 5.30 ± 1.40 postoperative with 5% (3.30 ± 2.95) loss of correction at final follow-up. Anterior vertebral height restored significantly from 55.80 ± 11.9% to 87.6 ± 13.1% postoperative with 4.5 ± 4.0% loss at final follow-up. One case had cement leakage was found, but the patient is asymptomatic. No implant-related complication was seen. No iatrogenic dural or nerve injury. Conclusions. Treatment with vertebroplasty with cement augmented screw fixation and direct decompression is a great option in treating such a complex situation in fragile age with fragile bones because. Vertebroplasty is viable option for restoring vertebral anterior column in patients who are considered as contraindications for vertebroplasty, like DGOU-4. It provides anterior support avoiding corpectomy, minimise blood loss and also duration of surgery. Addition of short segment fixation gives adequate support with less stress risers at the junctional area

The purpose of this study was to determine whether patients with a burst fracture of the thoracolumbar spine treated by short segment pedicle screw fixation fared better clinically and radiologically if the affected segment was fused at the same time. A total of 50 patients were enrolled in a prospective study and assigned to one of two groups. After the exclusion of three patients, there were 23 patients in the fusion group and 24 in the non-fusion group. Follow-up was at a mean of 23.9 months (18 to 30). Functional outcome was evaluated using the Greenough Low Back Outcome Score. Neurological function was graded using the American Spinal Injury Association Impairment Scale. Radiological outcome was assessed on the basis of the angle of kyphosis. Peri-operative blood transfusion requirements and duration of surgery were significantly higher in the fusion group (p = 0.029 and p < 0.001, respectively). There were no clinical or radiological differences in outcome between the groups (all outcomes p > 0.05). The results of this study suggest that adjunctive fusion is unnecessary when managing patients with a burst fracture of the thoracolumbar spine with short segment pedicle screw fixation