Osteoporotic vertebral fractures localized in the lumbar area significantly impact sagittal alignment.

Lumbar fractures and/or multiple fractures at the lumbar or thoracolumbar regions are risk factors for sagittal malalignment in patients older than 70 years old. Although patients with OVF show a huge capacity to compensate after the fractures, lumbar and TL lumbar fractures require closer monitoring. PURPOSE: To assess the impact of osteoporotic vertebral fractures on the sagittal alignment of the elderly and identify risk factors for sagittal malalignment. METHODS: We performed a retrospective study on a cohort of 249 patients older than 70 years old and diagnosed with osteoporosis who suffered chronic vertebral fractures. Demographic and radiological data were collected. Full-spine lateral X-rays were obtained to analyze the sagittal plane. Patients were classified according to the number and location of the fractures. Pearson's correlation coefficient was used to assess the relationships between the type of fractures and sagittal alignment. RESULTS: A total of 673 chronic fractures were detected in 249 patients with a mean number of vertebral fractures per patient of 2.7 ± 1.9. Patients were divided into 9 subgroups according to the location and the number of fractures. Surprisingly, any of the aggregated parameters used to assess sagittal alignment exceeded the threshold defined for malalignment. In the second part of the analysis, 41 patients with sagittal malalignment were identified. In this subpopulation, an overrepresentation of patients with lumbar fractures (34% vs. 11%) and an under-representation of thoracic fractures (9% vs. 34%) were reported. We also observed that patients with 3 or more lumbar or thoracolumbar fractures had an increased risk of sagittal malalignment. CONCLUSIONS: Lumbar fractures and/or multiple fractures at the lumbar or thoracolumbar regions are risk factors for sagittal malalignment in patients older than 70 years old. Although patients show a remarkable capacity to compensate, fractures at the lumbar and thoracolumbar regions need closer monitoring.

Instrumented lumbar fusion in patients over 75 years of age: is it worthwhile?-a comparative study of the improvement in quality of life between elderly and young patients.

Background: Surgical treatment of degenerative lumbar disease in the elderly is controversial. Elderly patients have an increased risk for medical and surgical complications commensurate with their comorbidities, and concerns over complications have led to frequent cases of insufficient decompression to avoid the need for instrumentation. The purpose of this study was to evaluate clinical outcome between older and younger patients undergoing lumbar instrumented arthrodesis. Methods: This is a retrospective, comparative study of prospectively collected outcomes. One hundred and fifty-four patients underwent 1- or 2-level posterolateral lumbar fusion. Patients were divided into two groups. Group 1: 87 patients ≤65 years of age who underwent decompression and posterolateral instrumented fusion; Group 2: 67 patients ≥75 years of age who underwent the same procedures with polymethylmethacrylate (PMMA) pedicle-screw augmentation. Mean follow-up 27.47 months (range, 76-24 months). Results: Mean age was 49.1 years old (range, 24-65) for the younger group and 77.8 (range, 75-86) in the elderly group. Patients ≥75 years of age showed higher preoperative comorbidity (American Society of Anesthesiology, ASA: 1.7 vs. 2.4), and ≥2 systemic diseases with greater frequency (12.5% vs. 44.7%). No significant differences were found between the two groups in terms of postoperative complications, fusion, or revision rate. During follow-up, adjacent disc disease and adjacent fracture occurred significantly more in Group 2 (P<0.05). At the end of follow-up, there were no significant differences between the two groups in any of the clinical and health-related quality of life scores or satisfaction with treatment received. Conclusions: Osteoporosis represents a major consideration before performing spine surgery. Despite an obvious increased risk of complications in elderly patients, PMMA-augmented fenestrated pedicle screw instrumentation in spine fusion represents a safe and effective surgical treatment option to elderly patients with poor bone quality. Age itself should not be considered a contraindication in otherwise appropriately selected patients.

Anatomic trajectory for iliac screw placement adapts better to the morphological features of the pelvis of each individual than the S2 alar iliac screw: a radiological study.

PURPOSE: The iliac fixation (IF) through the S2 ala permits the minimization of implant prominence and tissue dissection. An alternative to this technique is the anatomic iliac screw fixation (AI), which considers the perpendicular axis to the narrowest width of the ileum and the width of the screw. The morphological accuracy of the iliac screw insertion of two low profile iliac fixation (IF) techniques is investigated in this study. METHODS: Twenty-nine patients operated on via low profile IF technique were divided into two groups, those treated using 28 screws with the starting point at S2, and those treated with 30 AI entry point. Radiological parameters (Tsv-angle, Sag-Angle, Max-length, sacral-distance, iliac-width, S2-midline, skin-distance, iliac-wing, and PSIS distance) and clinical outcomes (early and clinic complications) were evaluated by two blinded expert radiologists, and the results were compared in both groups with the real trajectory of the screws placed. RESULTS: Differences between ideal and real trajectories were observed in 6 of the 9 evaluated parameters in the S2AI group. In the AI group, these trajectories were similar, except for TSV-Angle, Max-length, Iliac-width, and distance to iliac-wing parameters. Moreover, compared with S2AI, AI provided better adaptation to the pelvic morphology in all parameters, except for sagittal plane angulation, skin distance, and iliac width. CONCLUSIONS: AI ensures the advantages of low profile pelvic fixation like S2AI, with a starting point in line with S1 pedicle anchors and low implant prominence, and moreover adapts better to the morphological features of the pelvis of each individual.

Surgical Site Infection After Polymethyl Methacrylate Pedicle Screw Augmentation in Osteoporotic Spinal Vertebrae: A Series of 537 Cases.

BACKGROUND: Retrospective observational study of prospectively collected outcomes. OBJECTIVE: The use of transpedicular screws augmented with polymethyl methacrylate (PMMA) is an alternative for patients with osteoporotic vertebrae. To investigate whether using PMMA-augmented screws in patients undergoing elective instrumented spinal fusion (ISF) is correlated with an increased risk of infection and the long-term survival of these spinal implants after surgical site infection (SSI). METHODS: We studied 537 consecutive patients who underwent ISF at some point within a 9-year period, involving a total of 2930 PMMA-augmented screws. Patients were classified into groups: (1) those whose infection was cured with irrigation, surgical debridement, and antibiotic treatment; (2) those whose infection was cured by hardware removal or replacement; and (3) those in whom treatment failed. RESULTS: Twenty eight of the 537 patients (5.2%) developed SSI after ISF. An SSI developed after primary surgery in 19 patients (4.6%) and after revision surgery in 9 (7.25%). Eleven patients (39.3%) were infected with gram-positive bacteria, 7 (25%) with gram-negative bacteria, and 10 (35.7%) with multiple pathogens. By 2 years after surgery, infection had been cured in 23 patients (82.15%). Although there were no statistically significant differences in infection incidence between preoperative diagnoses (P = 0.178), the need to remove hardware for infection control was almost 80% lower in patients with degenerative disease. All screws were safely explanted while vertebral integrity was maintained. PMMA was not removed, and no recementing was done for new screws. CONCLUSIONS: The success rate for treatment of deep infection after cemented spinal arthrodesis is high. Infection rate findings and the most commonly found pathogens do not differ between cemented and noncemented fusion. It does not appear that the use of PMMA in cementing vertebrae plays a pivotal role in the development of SSIs.

Anterior 1-2 Level Cervical Corpectomy and Fusion for Degenerative Cervical Disease: A Retrospective Study With Lordotic Porous Tantalum Cages. Long-Term Changes in Sagittal Alignment and Their Clinical and Radiological Implications After Cage Subsidence.

BACKGROUND: Despite the advances in anterior cervical corpectomy and fusion (ACCF) as a reconstructive surgical technique, the rate of complications related to artificial implants remains high. The purpose of this study was to investigate the long-term clinical course of ACCF with tantalum trabecular metal (TTM)-lordotic implants. Focus is placed on the relevance and influence of implant subsidence on sagittal alignment and the related clinical implications. METHODS: Retrospective, observational study of prospectively collected outcomes including 56 consecutive patients with degenerative cervical disc disease (myelopathy and/or radiculopathy). All patients underwent 1-level or 2-level ACCF with TTM-lordotic implants. The mean duration of follow-up was 4.85 years. RESULTS: The fusion rate at the end of follow-up was 98.11% (52/53). Implant subsidence occurred in 44 (83.01%) cases, including slight subsistence (<3 mm) in 37 (69.81%) and severe subsidence (>3 mm) in 7 cases (13.2%). The greatest degree of subsidence developed in the first 3 months postoperatively (P = 0.003). No patients presented a significant increase in implant subsidence beyond the second year of follow-up. The most common site of severe subsidence was the anterior region of the cranial end plate (4/7). At the end of follow-up, C1-C7 lordosis and segmental-Cobb angle of the fused segment increased on average by 5.06 ± 8.26 and 1.98 ± 6.02 degrees, respectively, though this difference failed to reach statistical significance (P > 0.05). Visual analog scale and Neck Disability Index scores improved at the conclusion of follow-up (P < 0.05). CONCLUSIONS: ACCF with anterior cervical reconstruction using TTM-lordotic implants and anterior cervical plating for treatment of cervical degenerative disease has high fusion rates and good clinical outcome. The osteoconductive properties of TTM provide immediate stabilization and eliminate the need for bone grafts to ensure solid bone fusion. Before fusion occurs, asymptomatic implant settlement into the vertebral body is inevitable. However, lack of parallelism and reduced contact surface between the implant and the vertebral end plate are major risk factors for severe further subsidence, which may negatively affect the clinical outcomes.

Simplified Pedicle Subtraction Osteotomy for Osteoporotic Vertebral Fractures.

BACKGROUND: In osteoporotic vertebral fractures (OVF) involving neurological symptoms and severe kyphosis, vertebral osteotomies are necessary but are associated with a high risk of complications. METHODS: We performed a retrospective study. In 14 patients (mean age, 69.3 years old) with unstable thoracolumbar fractures associated with severe kyphosis, a posterior instrumentation with polymethylmethacrylate-augmented screws and a modified pedicle subtraction osteotomy (PSO) at the fracture level were performed to stabilize the spine and correct the kyphosis. The underlying principle behind the osteotomy's technique was to exaggerate the defect caused by the fracture and shorten the spine: (1) completion of a wide laminoforaminotomy, (2) use of successive reamers rotated in the pedicle at a 25° angle in the axial plane to obtain its complete decancellation, (3) insertion of the reamers in a more medial orientation (55°) to collapse the posterior wall, and (4) breakage of the lateral wall. Radiographic and clinical outcomes were analyzed pre- and postoperatively. Complications were reported. RESULTS: Functional scores improved after surgery. Oswestry disability index and visual analog scale scores decreased significantly (33 and 4 points, respectively). Patient satisfaction rate reached 93%. Average postoperative regional vertebral kyphosis was decreased to 3.79°. No dural tear or neurological injuries were observed. Blood loss of 920 mL (±350 mL) and two mechanical complications were reported. CONCLUSIONS: OVF can lead to severe deformities. In osteoporotic bones, the use of sequential reamers can simplify the PSO technique, allowing for the shortening and stabilization of the spine without manipulating the dural sac. The risk of neurological injuries and blood loss is decreased. LEVEL OF EVIDENCE: 4.

Lung injury in patients age 75 years and older with the use of polymethylmethacrylate fenestrated pedicle screws.

BACKGROUND CONTEXT: Pulmonary complications in patients age 75 years and older who undergo spinal fusion may have catastrophic consequences. The use of augmentation techniques with polymethylmethacrylate (PMMA) have been associated with pulmonary damage. The use of fenestrated pedicle screws augmented with PMMA may increase the risk of lung injury in this population. PURPOSE: To investigate whether the use of PMMA-augmented screws is correlated with increased lung injury in patients undergoing instrumented lumbar spinal fusion. STUDY DESIGN: A nonrandomized, prospective, case-controlled clinical study was carried out. PATIENT SAMPLE: We included 50 consecutive patients: 25 classifieds as patients who required PMMA-augmented screws in lumbar spinal fusion, and 25 classifieds as control participants because they underwent uncemented instrumented spinal fusion. OUTCOME MEASURES: We compare the incidence of the event, lung damage, in both groups by measuring a series of parameters: arterial blood gas, transesophageal echocardiography, urinary desmosine, and chest radiograph. The epidemiological parameters analyzed were age, sex, body mass index, status as a smoker, and number of cement leaks. METHODS: Changes in pulmonary damage markers were described in both groups of patients, comparing postsurgery values with baseline values. In control participants, each change was evaluated for the total number of patients. All changes are indicated in this report by mean differences for quantitative variables and by differing proportions for qualitative variables, with 95% confidence intervals provided for all values. RESULTS: There was an increase in postinstrumentation PaO2 (arterial partial pressure of oxygen) in both groups, probably related to the use of mechanical ventilation and recruitment maneuvers. Even though the group that required augmentation had lower baseline levels, the difference between groups was not statistically significant. On transesophageal echocardiographs, we observed scattered small, snowflake-like emboli, and bright echo signals appeared in the right atrium during PMMA injection. Signal density was constant but gradually faded away when PMMA injection ended. No participants in the group without augmentation had radiological complications. Overall, desmosine levels increased in both groups, and the rise was similar in both. There was a slight average increase in urine desmosine levels after instrumentation and progressively continues to rise until 24 hours after instrumentation, with a subsequent decrease at 72 hours. Comparing the two groups, we found no statistically significant differences at any time. CONCLUSIONS: We were not able to identify a significant difference in urine desmosine levels associated with the augmentation of with fenestrated pedicle screws with PMMA. Despite comparing patients age 75 years or older with a younger group, we found no clinical, analytical, or gasometric data indicating lung damage in patients who had augmentation.

Safety and Efficacy With Augmented Second-Generation Perforated Pedicle Screws in Treating Degenerative Spine Disease in Elderly Population.

BACKGROUND: Degenerative spine disease is a common cause of low back pain in people age 65 years or older. Nonsurgical treatment is tried first, but if it is unsuccessful, surgery is advocated. This has special connotations for both underlying disease and the biomechanical characteristics of osteoporotic bone. We conducted an observational study to investigate the clinical and radiological outcome in patients in this age group with poor bone quality and degenerative lumbar instability treated with fusion using perforated pedicle screws augmented with polymethylmethacrylate (PMMA). METHODS: We collected prospective data on treatment, outcome, and patient characteristics from our institution's database. The primary outcome was a change in pain and physical function measured by the visual analog scale, the Core Outcome Measures Index, and the Oswestry Disability Index. Control participants were also analyzed for secondary complications such as hardware mobilization, fusion (as apparent on radiographs), and adjacent fractures or adjacent degenerative disc disease. RESULTS: We included 89 patients who underwent surgery between October 2015 and February 2018 at a mean age of 78 years (range, 67-88 years) and were then monitored for at least 12 months (range, 12-40 months). Findings on pain and function questionnaires showed improvement at 6 months after surgery, maintained at the final evaluation; 90% of patients had final score increases of ≥15 points. No patient developed clinical complications secondary to PMMA leakages. One patient had nonunion and screw breakage. No other patient had clinical or radiological nonunion. Of the control participants, 6 had adjacent disc disease, with 2 of them requiring instrumentation extension. Six deep infections required surgical revision without removal of material. CONCLUSION: PMMA-augmented cannulated pedicle screw instrumentation in spine fusion effectively and safely treats degenerative lumbar disease in patients who are age 65 years or older with poor bone quality.

Spinal fusion achieves similar two-year improvement in HRQoL as total hip and total knee replacement. A prospective, multicentric and observational study.

INTRODUCTION: Total hip and knee arthroplasty (THA/TKA) are surgical procedures with proven benefits. Although the literature reports outcomes of fusion of the lumbar spine comparable to those of THA/TKA in general health-related quality-of-life (HRQoL) questionnaires, functional assessment is nevertheless needed for these results to be of use in clinical practice and management. Aim of our study was to prove that lumbar spinal fusion has similar if not better outcomes than THA/TKA using intervention-specific HRQoL questionnaires and functional assessment questionnaires. MATERIALS AND METHODS: Observational, ambispective, multicentre study of three cohorts undergoing lumbar spinal fusion (n = 115), THA (n = 119) and TKA (n = 253). Patients were evaluated using the Short-Form-12 (SF-12), Harris-Hip-Score, Hospital for Special Surgery Scale (HSS) and Oswestry Low Back Pain Disability questionnaires. A minimum follow-up of two years was conducted. RESULTS: The SF-12 showed significant improvement in all groups. The SF-12 physical component summary score indicated a more severe pre-operative status (p = 0.031) in the THA cohort. The mental component summary score indicated a less severe pre-operative status in the TKA cohort (p = 0.008) and greater post-operative improvement in the TKA and THA cohorts across follow-up (six months p = 0.021; one year p = 0.012; two years p = 0.042). Functional assessment indicated greater pre-operative disability in the THA group. At two years of follow-up, functional improvement according to the Harris, HSS and Oswestry questionnaires were 152.01%, 50.07% and 41.14% respectively. CONCLUSIONS: This study demonstrates that lumbar spinal fusion and total knee and hip arthroplasty are comparable in terms of functional improvement when thoroughly studied with health, quality-of-life and functional assessment questionnaires.

Challenges in the management of floating knee injuries: Results of treatment and outcomes of 224 consecutive cases in 10 years.

INTRODUCTION: Floating knee is a flail knee joint resulting from fractures of the shafts or adjacent metaphyses of the femur and the ipsilateral tibia. It is usually associated with several complications and mortality. This study was designed to present our experience with the treatment of this injury. MATERIAL AND METHOD: This study was performed between January 2004 and December 2014. 224 cases of floating knee injuries gathered from the 34,480 lower extremities trauma files were studied, and the target information recorded. The injuries most frequently occurred in subjects between 16 and 35 years of age (60.71%), and in male subjects (85.71%). The most frequent mechanism of injury was traffic accident (92.85%). External fixation was the common type of treatment (82.14%) in emergency or as a definitive treatment. The treatment was performed within 24 h of the trauma. We performed a 36-month follow up with clinical examination, radiographs, assessing the complications, and using the Modified Cincinnati Rating System Questionnaire (MCRSQ) and the Karlström/Olerud Score (KOS) to evaluate the progression of the outcomes. RESULTS: Early complications included 8 cases of compartment syndrome, 60 open fractures and 24 partially amputated limbs. A total amputation was performed in 3 patients. The most common late complication was heterotopic calcifications of the knee (n = 68, 30.6%). Good scores for MCRSQ and KOS were obtained only after patients were sent to a reference center for knee surgery. CONCLUSIONS: Our experience revealed that the complication rate associated with floatingknee injuries remains high, regardless of the performed treatment. Surgeons should focus on reducing complications while treating these severe injuries.

WITHDRAWN: Challenges in the management of floating knee injuries: Results of treatment and outcomes of 224 consecutive cases in 10 years.

The Publisher regrets that this article is an accidental duplication of an article that has already been published in Injury, 50(2) (2019) 453­461, https://doi.org/https://doi.org/10.1016/j.injury.2018.12.009. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Comminuted Bilateral Simultaneous Fracture and Luxation of the Proximal Humerus with an Injury to the Right Axillary Artery.

INTRODUCTION: Among all of the shoulder dislocation cases, only 1% is related to fractures. The simultaneous bilateral fracture and dislocation happen very rarely and it is seldom related to a trauma. An injury to the axillary artery related to a humerus fracture is an exceptional event. CASE REPORT: A 58-year-old male with no particular background who, after falling from a 5 m height, presented a fracture and dislocation of both of his shoulders and showed no pulse in his right arm due to an injury to his axillary artery. The peculiarity of this injury increases when the axillary artery injury is added to the bilateral fracture and luxation of the humerus. We present the case and revise literature. CONCLUSION: The treatment for these complex injuries requires a multidisciplinary surgical approach. To treat these injuries, an early diagnose is essential regarding the fact that the prognosis is directly related to the time elapsed without blood circulation. That is why it is necessary to look for these arterial injuries in case of a proximal humerus fracture.

Osteoporosis and the Management of Spinal Degenerative Disease (I).

Osteoporosis has become a major medical problem as the aged population of the world rapidly grows. Osteoporosis predisposes patients to fracture, progressive spinal deformities, and stenosis, and is subject to be a major concern before performing spine surgery, especially with bone fusions and instrumentation. Osteoporosis has often been considered a contraindication for spinal surgery, while in some instances patients have undergone limited and inadequate procedures in order to avoid concomitant instrumentation. As the population ages and the expectations of older patients increase, the demand for surgical treatment in older patients with osteoporosis and spinal degenerative diseases becomes progressively more important. Nowadays, advances in surgical and anesthetic technology make it possible to operate successfully on elderly patients who no longer accept disabling physical conditions. This article discusses the biomechanics of the osteoporotic spine, the diagnosis and management of osteoporotic patients with spinal conditions, as well as the novel treatments, recommendations, surgical indications, strategies and instrumentation in patients with osteoporosis who need spine operations.

Degenerative Cervical Disc Disease: Long-term Changes in Sagittal Alignment and Their Clinical Implications After Cervical Interbody Fusion Cage Subsidence: A Prospective Study With Standalone Lordotic Tantalum Cages.

STUDY DESIGN: A retrospective, observational study of prospectively collected outcomes. OBJECTIVE: To investigate the long-term clinical course of anterior cervical discectomy and fusion with interbody fusion cages (ACDF-IFC) with lordotic tantalum implants and to correlate the radiologic findings with the clinical outcomes, with special emphasis on the significance and the influence of implant subsidence. SUMMARY OF BACKGROUND DATA: Cage subsidence is the most frequently reported complication after ACDF-IFC. However, most reports fail to correlate cage subsidence with lower fusion rates or with unsatisfactory clinical results. METHODS: Forty-one consecutive patients with symptomatic degenerative cervical disk disease with failure of conservative treatment were included. All patients underwent 1-/2-level ACDF-IFC with lordotic tantalum implants. The mean follow-up was 4.91 years. RESULTS: The final follow-up fusion rate was 96.96% (32/33). The interspace height (IH) at the affected levels was significantly incremented after implant insertion, and despite a gradual loss in the height over time, the final follow-up IH was significantly higher than that measured preoperatively (P<0.0001). Anterior IH and posterior IH lost 55.8% and 76.2% of the initially incremented height, respectively, with a final increase of 72% in the AIH-PIH height differential. Implant subsidence (>3 mm) occurred in 11 disk spaces (26.82%). Preoperative and postoperative IH were significantly higher in subsidence patients; however, there was no difference in the final follow-up IH (P>0.05). Patients with ≥3 years of follow-up (n=29) did not demonstrate further significant subsidence beyond the second year. Regarding C1-C7 lordosis, the segmental Cobb angle, the cervical Visual Analogue Scale, and Neck Disability Index questionnaires, no difference between patients with or without final follow-up endplate subsidence was encountered. CONCLUSIONS: Until fusion occurs, tantalum cage settlement into the vertebral body is to be expected. Further subsidence could be the result of segmental adaptative changes. Graft subsidence did not affect the clinical outcome in any of our patients during long-term follow-up. The occurrence of dynamical implant subsidence had a positive effect on cervical lordosis, especially at the posterior IH.

Timing of PMMA cement application for pedicle screw augmentation affects screw anchorage.

INTRODUCTION: Cement augmentation is an established method to increase the pedicle screw (PS) anchorage in osteoporotic vertebral bodies. The ideal timing for augmentation when a reposition maneuver is necessary is controversial. While augmentation of the PS before reposition maneuver may increase the force applied it on the vertebrae, it bears the risk to impair PS anchorage, whereas augmenting the PS after the maneuver may restore this anchorage and prevent early screw loosening. The purpose of the present study was to evaluate the effect of cement application timing on PS anchorage in the osteoporotic vertebral body. METHODS: Ten lumbar vertebrae (L1-L5) were used for testing. The left and right pedicles of each vertebra were instrumented with the same PS size and used for pairwise comparison of the two timing points for augmentation. For the reposition maneuver, the left PS was loaded axially under displacement control (2 × ±2 mm, 3 × ±6 mm, 3 × ±10 mm) to simulate a reposition maneuver. Subsequently, both PS were augmented with 2 ml PMMA cement. The same force as measured during the left PS maneuver was applied to the previously augmented right hand side PS [2 × F (±2 mm), 3 × F (±6 mm), 3 × F (±10 mm)]. Both PS were cyclically loaded with initial forces of +50 and -50 N, while the lower force was increased by 5 N every 100 cycles until total failure of the PS. The PS motion was measured with a 3D motion analysis system. After cyclic loading stress, X-rays were taken to identify the PS loosening mechanism. RESULTS: In comparison with PS augmented prior to the reposition maneuver, PS augmented after the reposition maneuver showed a significant higher number of load cycles until failure (5930 ± 1899 vs 3830 ± 1706, p = 0.015). The predominant loosening mechanism for PS augmented after the reposition maneuver was PS toggling with the attached cement cloud within the trabecular bone. While PS augmented prior to the reposition, maneuver showed a motion of the screw within the cement cloud. CONCLUSION: The time of cement application has an effect on PS anchorage in the osteoporotic vertebral body if a reposition maneuver of the instrumented vertebrae is carried out. PS augmented after the reposition maneuver showed a significant higher number of load cycles until screw loosening.

Osteoporosis and the Management of Spinal Degenerative Disease (II).

Osteoporosis has become a major medical problem as the aged population of the world rapidly grows. Osteoporosis predisposes patients to fracture, progressive spinal deformities, and stenosis, and is subject to be a major concern before performing spine surgery, especially with bone fusions and instrumentation. Osteoporosis has often been considered a contraindication for spinal surgery, while in some instances patients have undergone limited and inadequate procedures in order to avoid concomitant instrumentation. As the population ages and the expectations of older patients increase, the demand for surgical treatment in older patients with osteoporosis and spinal degenerative diseases becomes progressively more important. Nowadays, advances in surgical and anesthetic technology make it possible to operate successfully on elderly patients who no longer accept disabling physical conditions. This article discusses the biomechanics of the osteoporotic spine, the diagnosis and management of osteoporotic patients with spinal conditions, as well as the novel treatments, recommendations, surgical indications, strategies and instrumentation in patients with osteoporosis who need spine operations.

Misdiagnosis of sacral stress fracture: an underestimated cause of low back pain in pregnancy?

BACKGROUND: Sacral stress fracture during pregnancy is an uncommon condition with unclear pathophysiology, presenting with non-specific symptoms and clinical findings. To date, few cases have been published in the literature describing the occurrence of sacral stress fracture during pregnancy. CASE REPORT: We report a 28-year-old primigravid patient who developed lumbosacral pain at the end of the second trimester. Symptoms were overlooked throughout pregnancy and the postpartum period, resulting in the development of secondary chronic gait and balance problems. CONCLUSIONS: Stress fracture of the sacrum should be included in the differential diagnosis of low back and sacral pain during pregnancy. Its prevalence is probably underestimated because of the lack of specificity of the symptoms. Plain radiographs are not appropriate due to radiation exclusion; magnetic resonance is the only method that can be applied safely. There is limited information on natural history but many patients are expected to have a benign course. However, misdiagnosis may lead to prolonged morbidity and the development of secondary gait abnormalities. Stress fracture of the sacrum should be included in the differential diagnosis of low back and sacral pain during pregnancy. A high index of suspicion is necessary to establish an early diagnosis and appropriate treatment.