Complications in endoscopic spine surgery: a systematic review.

PURPOSE: This systematic review aims to investigate the complication rate of endoscopic spine surgeries, stratifying them by technique, district and kind of procedure performed. METHODS: This study was conducted according to the PRISMA statement. The literature search was conducted in MEDLINE, CINAHL, EMBASE, Cochrane Register, OTseeker and ScienceDirect database. Types of studies included were observational studies (cohort studies, case-control studies and case series) and randomised or quasi-randomised clinical with human subjects. No restrictions on publication year were applied. Repeated articles, reviews, expert's comments, congress abstracts, technical notes and articles not in English were excluded. Several data were extracted from the articles. In particular, data of perioperative (≤ 3 months) and late (> 3 months) complications were collected and grouped according to: (1) surgical technique [uniportal full-endoscopic spine surgery (UESS) or unilateral biportal endoscopic spine surgery (UBESS)]; (2) spinal district treated [cervical, thoracic or lumbar] and (3) type of procedure [discectomy/decompression or fusion]. Complication analysis was performed in subgroups with at least 100 patients to have clinically meaningful statistical validity. RESULTS: A total of 117 full-text articles were assessed for eligibility. Of the 117 records included, 95 focused their research on UESS (14 LOE V, 33 LOE IV, 43 LOE III and five LOE II) and 23 on UBESS (three LOE V, eight LOE IV, 10 LOE III and two LOE II). A total of 20,020 patients were extracted to investigate the incidence of different perioperative and late complications, 10,405 for UESS and 9615 for UBESS. CONCLUSION: The present study summarises the complications reported in the literature for spinal endoscopic procedures. On the one hand, the most relevant described were perioperative complications (transient neurological deficit, dural tear and dysesthesia) that are especially meaningful for endoscopic discectomy and decompression. On the other hand, late complications, such as mechanical implant failure, are more common in endoscopic interbody fusion. LEVEL OF EVIDENCE: I.

Should the pelvis be included? An analysis of distal junctional failure risk factors in correcting adult spinal deformity in women with fusion to L5.

PURPOSE: To identify the risk factors for distal junctional failure (DJF) in women treated for adult spine deformity with fusion to L5 and to highlight the significance of preoperative assessment, surgical decision-making, and postoperative care. METHODS: This is a retrospective study of data collected prospectively on the local institutional spine surgery registry (2016-2021). All patients, women older than 18 years, with a diagnosis of adult spine deformity who underwent long posterior instrumentation to L5 and had a minimum of 2-years follow-up were included in the study (two groups: with or without DJF). Demographic and radiographic data, corrective strategy, preoperative level of degeneration at L5/S1 and GAP score were compared between the two groups. RESULTS: Forty-eight patients (n = 48) satisfied eligibility criteria. At two-years follow-up, nine patients (18,7%) developed a DJF that required surgical revision. Thirty-nine patients did not present distal junctional complications. Patients with or without DJF showed significant differences in terms of preoperative spinopelvic parameters (PT: 28°± 6° vs. 23°± 9°, p-value 0.05; DJF group vs. not DJF) and degeneration of L5-S1 (Pfirmann grade L5-S1 disc 3.7 ± 1.0 vs. 2.6 ± 0.8, p-value 0.001; DJF group vs. not DJF) (L5-S1 Facet joint Osteoarthritis 3.1 ± 0.8 vs.2.4 ± 0.8, p-value 0.023; DJF group vs. not DJF). CONCLUSION: DJF following spinal deformity correction surgery is influenced by a combination of patient-related, surgical and implant-related factors. Fusion construct length, preoperative and postoperative sagittal alignment and the grade of degeneration of the distal disc have been identified as significant risk factors. Surgeons should carefully evaluate these factors and employ appropriate strategies.

The influence of peri-operative depressive symptoms on medium-term spine surgery outcome: a prospective study.

PURPOSE: To investigate the role of depressive symptoms on clinical outcomes in patients undergoing spinal surgery up to 2-year follow-up. METHODS: The study used data from an institutional spine surgery registry (January 2016, through March 2022) to identify patients (> 18 years) undergoing spine surgery. Patients with Oswestry Disability Index (ODI) < 20/100 at baseline or undergoing surgery on the cervical spine or for idiopathic spinal deformity and trauma patients were excluded. The patients were divided into two groups based on the pre-operative Mental Component Summary (MCS) score of the SF-36: depression group (MCS ≤ 35) or non-depression group (MCS > 35). The ODI and MCS scores trajectory were wined over the 24-month post-surgery between groups. Additionally, a secondary subgroup analysis was conducted comparing outcomes between those with depressive symptoms (persistent-depression subgroup) and those without depressive symptoms (never-depression subgroup) at 3 months after surgery. RESULTS: A total of 2164 patients who underwent spine surgery were included. The pre-operative depression group reported higher ODI total scores and lower MCS than the pre-operative non-depression group at all time points (P < 0.001). The persistent-depression subgroup reported higher ODI total scores and lower MCS than the never-depression subgroup at all follow-ups (P < 0.001). CONCLUSION: Functional disability and mental health status improve in patients with depression symptoms undergoing spinal surgery. Despite this improvement, they do not reach the values of non-depressed subjects. Over the 2-year follow-up time, patients with depression show a different trajectory of ODI and MCS. Caregivers should be aware of these results to counsel patients with depression symptoms.

En-bloc resection of a chordoma in L3 by a combined open posterior and less invasive retroperitoneal approach: technical description and case report.

INTRODUCTION: To fulfill oncological criteria, extensive open anterior and posterior approaches are usually performed in the lumbar spine to obtain an appropriate en-bloc spondylectomy. It is commonly accepted that the price of a tumor-free margin includes such extensive incisions and soft-tissue damage, with consequent relevant blood loss and possible postoperative complications as delayed wound healing. In this article, a case of chordoma in L3 is presented, submitted to an oncologically appropriate en-bloc resection performed by an open posterior approach combined with a mini-retroperitoneal approach. The successful oncologic procedure was combined with a short and uneventful postoperative course. MATERIALS AND METHODS: The authors present the surgical technique and the possible challenges of minimally invasive anterior oncologic surgery as a contribution to a limited literature. RESULTS: Up to date, palliative care of single metastases has been the main setting in which anterior, minimally invasive surgery has been performed in the lumbar spine. The authors explained how, in selected cases, this approach can be performed in combination with an open posterior access for an oncologically appropriate treatment of a primary malignant tumor. CONCLUSION: Anterior, minimally invasive surgery can have a role in selected patients with primary malignant tumors of the lumbar spine. The surgical team should have extensive training both in oncologic and minimally invasive surgery.

Post-operative L5 radiculopathy after L5-S1 hyperlordotic anterior lumbar interbody fusion (HL-ALIF) is related to a greater increase of lordosis and smaller post-operative posterior disc height: results from a cohort study.

STUDY DESIGN: A single-centre retrospective study. BACKGROUND AND PURPOSE: This study aims to investigate the rate of L5 radiculopathy, to identify imaging features associated with the complication and to evaluate the clinical outcomes in adult spine deformity patients undergoing L5-S1 ALIF with hyperlordotic cages. METHODS: Design: retrospective cohort study. A single-centre prospective database was queried to analyse patients undergoing hyperlordotic (HL) ALIF with posterior fusion to correct spinal deformity. Clinical status was evaluated by back and leg pain numeric rate scale and Oswestry Disability Index pre-operatively and at 3-, 6- and 12-month follow-up. Spinopelvic parameters, such as pelvic incidence, pelvic tilt, lumbar lordosis and L5-S1 lordosis, posterior disc height (PDH) and anterior disc height, were assessed pre-operatively and post-operatively on standardized full-spine standing EOS images. The sagittal foraminal area was measured pre- and post-operatively on a CT scan. RESULTS: Thirty-nine patients with a mean age of 63.2 ± 8.6 years underwent HL-ALIF from January 2016 to December 2019. Seven of them developed post-operative root pain (5) or weakness (2) (Group A), while thirty-two did not (Group B). Root impairment was associated with greater segmental correction magnitude, 26° ± 11.1 in Group A versus 15.1° ± 9.9 in Group B (p < 0.05), and to smaller post-operative PDH, 5.9 mm ± 2.7 in Group A versus 8.3 mm ± 2.6 (p < 0.05). CONCLUSIONS: Post-operative root problems were observed in 17.9% of patients undergoing HL-ALIF for adult spine deformity. L5 radiculopathy was associated with larger sagittal angular corrections and smaller post-operative posterior disc height. One patient (2.6%) needed L5 root decompression. At 12 months of follow-up, results were equivalent between groups. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Long spine fusions to the sacrum-pelvis are associated with greater post-operative proximal junctional kyphosis angle in sitting position.

STUDY DESIGN: A single-centre retrospective study. BACKGROUND AND PURPOSE: Although adult patients spend most of their time in sitting positions, the assessment of spinopelvic parameters in adult deformity surgery is commonly performed in standing X-rays. Our study compares the standing and sitting sagittal alignment parameters in subjects who underwent thoracolumbar fusion. METHODS: Patients who underwent corrective surgery for adult scoliosis with at least five instrumented vertebra were stratified according to the upper instrumented vertebra (UIV) and pelvic fixation. Group A:UIV proximal to T6 with pelvis fixation. B:UIV lower than T6 and pelvic fixation. Group C: thoracolumbar fusion without pelvic fixation. Post-operative spinopelvic sagittal parameters were measured in both standing and sitting X-rays. RESULTS: A total of 51 patients were enrolled in the study (11:Males and 40:Females). The mean age was 52.3 ± 21.7y/o. The comparison of post-operative standing and sitting X-ray within the group A and B showed that a significant change was observed in terms of JA-Junctional Angle-(Group A 6.3 ± 4.3 vs. 8.1 ± 3.3, p value = 0.03) (Group B 8.5 ± 6.4 vs. 10.9 ± 6.4, p value = 0.02). Group C showed statistically significant difference in terms of PT (15.6 ± 11.2 vs. 19.3 ± 9.2, p value = 0.04), AVA-Acetabular Version Angle-(41.1 ± 5.9 vs. 48.3 ± 6.6, p value < 0.01) and LL (- 51.3 ± 16.0 vs. - 42.6 ± 10.7, p value < 0.01). CONCLUSION: In our series, the post-operative sagittal alignment showed peculiar behaviours and adaptations in sitting position, depending on the length and the site of the instrumented area. If the pelvis is included, the JA tends to significantly increase in sitting position. These findings can improve the knowledge of pathologies as proximal junctional kyphosis or specific cases of anterior hip impingement. LEVEL OF EVIDENCE: IV.

Vertebroplasty shows no antitumoral effect on vertebral metastasis: a case-based study on anatomopathological examinations.

PURPOSE: Percutaneous vertebroplasty (VTP) is a well-known surgical technique used for pain management and vertebral consolidation in the treatment of osteolytic metastases of the spine. While this indication is proven and commonly accepted, an antitumoral effect of polymethylmethacrylate (PMMA) has been proposed but not yet demonstrated. The aim of our study is to evaluate the evidences of antitumoral effect on anatomopathological examination. We present a small series of pathology findings after VTP for spine metastases that support the lack of antitumoral effect of PMMA. METHODS: We have retrospectively analyzed three cases of patients treated for en bloc excision of recurrent spine metastases previously submitted elsewhere to VTP on the same levels. We discuss our results with the literature reporting of an antitumoral effect of VTP. RESULTS: In our series, after anatomopathological examination, a cement-induced tumor necrosis was never found. Conversely, a foreign-body reaction around the cement was found, inside vital tumor. These results are consistent with an immune reaction to a foreign body without evidences of an antitumoral effect of PMMA. CONCLUSION: The antitumoral effect of PMMA should not be taken into account as an indication for VTP in spinal metastases. It is important not to misuse VTP as a therapy aiming at tumor control. Other therapies such as radiotherapy, radiosurgery and open surgery are available for that purpose.

Revision surgery for tumors of the thoracic and lumbar spine: causes, prevention, and treatment strategy.

INTRODUCTION: Revision surgery in spine tumor surgery can offer peculiar challenges given the severity of the majority of these lesions and the complexity of surgical procedures that are required. MATERIALS AND METHODS AND RESULTS: Based on literature review and on personal experience, surgical site infection, cerebrospinal fluid leakage, tumor recurrence and hardware failures are some of the possible causes of surgical revision in this set of patients. CONCLUSIONS: The aim of this study is to evaluate the most frequent complications that can lead to revision in spine tumor patients, to provide suggestions on how to prevent these events and to offer reasonable strategies to properly plan and perform a revision surgery. These slides can be retrieved under Electronic Supplementary Material.

Denosumab in the treatment of giant cell tumor of the spine. Preliminary report, review of the literature and protocol proposal.

BACKGROUND: The interest on the role of Denosumab in the treatment strategy of giant cell tumor of the spine is growing. En bloc resection is considered the Enneking appropriate treatment, but morbidity and functional loss are sometimes unacceptable. Denosumab could play a role as a stand-alone treatment, but also as preoperative treatment or as postoperative after intralesional surgery. MATERIALS AND METHODS: A cohort of 10 out of 12 cases of spinal GCT consecutively treated with Denosumab are analyzed and discussed compared to the cases reported in the literature. A staging of the radiological effect of the treatment is proposed. RESULTS: The stand-alone and postoperative treatments are still running (12 to 88 months). One therapy was stopped after 15 months, once a satisfactory local effect was achieved, but the treatment had to be restarted 2 months later due to the recurrence of the erosive images. The new treatment was successful. At 1-year follow-up after the gross total excision followed by postoperative Denosumab treatment, no evidence of local recurrence was found. The preoperative treatment duration ranged from 3 to 24 months. No local recurrence followed the en bloc resections. CONCLUSIONS: Denosumab alone is effective in relieving pain, increasing the ossification and sometimes reducing the tumor volume. It can be considered an excellent solution in spine GCTs whose surgical treatment cannot be Enneking appropriate or is associated with unacceptable morbidity or loss of functions. It is still impossible to state when to safely stop the treatment. Denosumab also plays a role as preoperative protocol. These slides can be retrieved under Electronic Supplementary Material.

Useful and innovative methods for the treatment of postoperative coronal malalignment in adult scoliosis: the "kickstand rod" and "tie rod" procedures.

STUDY DESIGN: Surgical technique description and case series. OBJECTIVE: To describe the use of two techniques for the correction of postoperative coronal imbalance after surgical treatment for adult spine deformity (ASD). Sagittal and coronal spinal malalignments are often present in patients with ASD or in patients who have undergone spine surgery. Surgical correction of coronal imbalance is insufficiently investigated, and the literature provides a limited spectrum of surgical options when compared to sagittal imbalance. Nevertheless, this deformity can compromise the surgical outcome and can increase the risk of hardware failure. METHODS: The kickstand (KR) and tie rod (TR) techniques utilize an accessory rod, linking the previous instrumentation to an independent iliac screw. After a proper release of the lumbar spine with anterior release or posterior osteotomies, the KR technique pushes with distraction on the concave side, whereas the TR technique pulls with compression on the convex side. Four patients (mean age, 64 years; SD 5.7) affected by severe postoperative coronal imbalance were treated. C7-PL ranges from 39 to 76 mm. The mean preoperative ODI was 70/100 (range from 55 to 82). All patients had previous spinopelvic fixation as a consequence of corrective surgery for adult spine deformity. The patients were surgically treated with the addition of supplementary rods connected to the ilium. The rods were used in the concavity or convexity of the deformity functioning as "kickstand" or "tie" or a combination of both. RESULTS: The mean surgical correction of C7-PL was 35 mm (range from 20 to 52 mm). In particular, the mean correction for kickstand rod technique was 26 mm and for tie rod technique was 43 mm. All of the patients improved their preoperative disability, and mean ODI was 30/100 (range from 10 to 60) at median 19-month follow-up. All postoperative imaging showed implants were in proper position without hardware failure. All of the patients treated demonstrated an immediate postoperative improvement in terms of coronal displacement of the spine. No complications were observed. At 1-year follow-up, all of the patients remained satisfactory in terms of clinical outcomes. CONCLUSION: The kickstand and tie rod techniques are effective in the treatment of postoperative coronal malalignment. Further studies are needed to confirm these findings. LEVEL OF EVIDENCE: V: Case report. These slides can be retrieved under Electronic Supplementary Material.

Composite PEEK/carbon fiber rods in the treatment for bone tumors of the cervical spine: a case series.

INTRODUCTION: Radiotherapy (RT) is frequently applied as an adjuvant therapy during spinal tumors treatment. Metallic implants can interfere with RT planning and execution, as it is known that metallic implants produce a backscattering effect that can limit RT accuracy and their presence can be associated with unwanted dose increase. PEEK/carbon fiber implants are designed to reduce these problems but their application in the cervical spine is limited, due to the reduced number and types of implants, the screw dimensions and the absence of lateral mass screws. We propose a hybrid system made of carbon rods and screws coupled with subliminal polyester bands with titanium clamps. We designed this hybrid construct to enclose the cervical region in the area of instrumentation without limiting the application of postoperative radiotherapy. MATERIALS AND METHODS: Six patients in which the hybrid hardware was implanted were retrospectively examined. Data on demographics, intraoperative and postoperative events, tumor details and staging and cervical alignment were collected pre- and postoperatively. RESULTS: No intraoperative complications occurred. En bloc resection was performed in two patients, while the remaining four received an intralesional resection. Three out of six patients received postoperative RT, without any alteration in its planning and administration. DISCUSSION AND CONCLUSIONS: Hybrid implants made of composite PEEK/carbon fiber screws and rods and sublaminar bands are a helpful solution for spinal reconstruction in the cervical and cervico-thoracic regions after spine tumor surgery. The implants do not produce artifacts at postoperative images, easing the planning and execution of postoperative radiotherapy.

Pedicle screw insertion with patient-specific 3D-printed guides based on low-dose CT scan is more accurate than free-hand technique in spine deformity patients: a prospective, randomized clinical trial.

BACKGROUND: Screw misplacement incidence can be as high as 15-30% in spine deformity surgery, with possible devastating consequences. Some technical solutions to prevent misplacement require expensive devices. MySpineTM comprises a low-dose CT scan of the patient's spine to build a virtual model of the spine to plan the screw trajectories and a 3D-printed patient-specific guide system to prepare the screw trajectories and to implant the screws in the vertebrae in order to increase reproducibility and safety of the implants. The aim of this open-label, single-center, prospective randomized clinical trial with independent evaluation of outcomes was to compare the accuracy of free-hand insertion of pedicle screws to MySpineTM 3D-printed patient-specific guides. METHODS: Twenty-nine patients undergoing surgical correction for spinal deformity were randomized to Group A (pedicle screws implantation with MySpineTM) or Group B (free-hand implantation). Group A received 297 pedicle screws, and Group B 243 screws. Forty-three screws in Group A crossed over to free-hand implantation. Screw position was graded according to Gertzbein in grades 0, A, B or C, with grades 0 or A considered as "safe area." Total fluoroscopy dose and time were compared in six patients of each group. RESULTS: Comparing the two study groups, we observed a statistically significant difference between the two groups (p < 0.05), with 96.1% of screws in the "safe area" in Group A versus a 82.9% in Group B. Group-A patients had a mean effective dose of 0.23 mSv compared to 0.82 mSv in Group B. Patient-specific, 3D-printed pedicle screw guides increase safety in a wide spectrum of deformity conditions. In addition, the total radiation dose is reduced, even considering the need of a low-dose preoperative CT for surgical planning. LEVEL OF EVIDENCE: I. These slides can be retrieved under Electronic Supplementary Material.

Correction to: Primary vascular bone tumors in the spine: a challenge for pathologists and spine oncology surgeons.

Unfortunately, the affiliation for the following authors was incorrectly published in the original publication.

Primary vascular bone tumors in the spine: a challenge for pathologists and spine oncology surgeons.

PURPOSE: Primary vascular bone tumors of the spine represent a challenge for oncology surgeons, due to the need of planning a surgical strategy appropriate to the tumor behavior. But these tumors represent a challenge also for pathologists, as immunohistochemical and molecular analyses have recently refined the terminology. METHODS: A cohort of 81 cases was retrospectively reviewed, targeting the evolution of diagnoses and the treatment-related outcome. Sixty-six cases (including one case originally diagnosed as chordoma) were diagnosed before 2011, and 15 were diagnosed and treated in the period 2011-2017. Fully documented outcome studies are available for 46 patients whose immunohistochemical and molecular analyses were available. The follow-up ranges from 6 months of the early patient death to 300 months of the longest disease-free survival. RESULTS: The outcome was related not only to the treatment performed, but also to the evolution of diagnoses. The term Hemangioendothelioma that defined a benign aggressive (Enneking stage 3) tumor is now obsolete and replaced by the diagnosis of Epithelioid Hemangioma for benign aggressive tumor and Epithelioid Hemangioendothelioma for low-grade malignant tumor. En bloc resection was appropriate for local control, but 2 out of 7 cases of epithelioid Hemangioendotheliomas died due to the spread of the disease None of the Hemangiomas recurred after intralesional excision with or without radiotherapy, or after vertebroplasty. Both cases of Angiosarcoma had a fast and lethal evolution. CONCLUSIONS: Surgeons must be aware of the evolution of terminology to decide the most appropriate treatment options. These slides can be retrieved from Electronic Supplementary Material.

Spondylolisthesis and tumors: a treatment algorithm.

BACKGROUND: Pars defect and spondylolisthesis are frequent conditions, while bone tumors-particularly the primaries-are rare. The contemporary occurrence can delay the diagnosis of the tumor, if symptoms are considered related to spondylolisthesis, or can make reconstruction more demanding. To our knowledge, only two case reports of this contemporary occurrence have been published in the literature. Being such rare, guidelines on surgical treatment have not been proposed yet. MATERIALS AND METHODS: A retrospective review of patients treated for spine bone tumors by the senior author from 1990 to 2017 was performed to find cases of contemporary occurrence of spondylolisthesis and/or pars defect and spine bone tumors. General health data, radiological imaging, histological tumor diagnosis, treatment, and follow-up were analyzed and discussed. RESULTS: Among the 1870 patients treated for spinal tumors between 1990 and 2017 by the senior author, 14 cases of association between tumors and spondylolysis/spondylolisthesis were observed. The cohort includes five males (35.7%) and nine females (64.3%), aged 14-72. Mean age of patients at surgery time was 47. CONCLUSIONS: Interactions between spondylolisthesis and bone tumors of the spine are episodic. These two conditions rarely occur in the same patient. No treatment strategy has been described until now. The target of this paper is to propose an algorithm to surgically treat patients with concomitant bone tumor and spondylolisthesis. This classification identifies a treatment-oriented algorithm based on two major categories: type A, bone tumor arising on the same vertebra or to an adjacent level; type B, bone tumor arising at least one unit far from the spondylolisthesis. This algorithm can help the surgeon facing this rare combination of diseases in the appropriate preoperative planning. These slides can be retrieved under Electronic Supplementary Material.

The effect of case-based discussion of topics with experts on learners' opinions: implications for spinal education and training.

PURPOSE: This investigation aimed to examine the extent to which case-based discussion with experts could influence the audience's opinions on the treatment of patients during a continuing medical education event for spine surgeons. METHODS: We conducted a prospective controlled crossover study of 90 surgeons. During a continuing medical education activity using case-based discussion, quiz questions were used which asked participants (attendants and faculty group) their opinions on the best choices about diagnosis and treatment in a number of cases. No answer was considered correct, but we evaluated the number of participants choosing each specific answer among a number of valid options. Quiz questions were collected with an automated response system at the entry and at the end of each case discussion. Change in participant's opinions was estimated from the change in the preferred answers between the entry and exit quizzes. Chi-square analysis was performed to determine significance. RESULTS: Sixty-two attendants out of eighty three (75%) and six faculties out of twelve (50%) responded to the survey. After the case discussion, 68.2% (p < 0.04, Chi-square test) of the attendants changed their opinion on the appropriate treatment. The faculty answers, however, showed no significant change in opinions regarding the identification of the appropriate treatment. CONCLUSIONS: On the basis of our results, case-based discussion driven by experts, as a form of teaching, has a measurable effect in terms of changes in the learners' opinions.

Vitamin D's Effect on the Proliferation and Inflammation of Human Intervertebral Disc Cells in Relation to the Functional Vitamin D Receptor Gene FokI Polymorphism.

Vitamin D is known to have immunomodulatory effects, is involved in osteo-cartilaginous metabolism, and may have a role in human intervertebral disc pathophysiology. Although a link between vitamin D receptor (VDR) gene variants and disc degeneration-related pathologies has been observed, its functional contribution to pathologic processes has not been assessed yet. The aim of this study was to investigate the response of disc cells to vitamin D in terms of the regulation of proliferation, metabolism, and inflammatory processes, with a particular focus on the FokI VDR genotype. However, although it was found that vitamin D had a pro-apoptotic effect regardless of genotype, an up-regulation of IL-1Ra and downregulation of IL-6 was found to be evident only in Ff cells. Regarding the metabolic effects, in Ff cells, vitamin D promoted an upregulation of the aggrecan in inflammatory conditions but did not have an effect on the expression of collagen-related markers. Moreover, cells bearing the Ff genotype were the most responsive to vitamin D in the upregulation of catabolic markers. In addition, in contrast to the FF genotype, vitamin D downregulated the vitamin D-dependent signaling pathway in inflamed Ff cells, counteracting the inflammation-mediated catabolic effects. In conclusion, Ff cells were found to be more responsive to the anti-inflammatory and catabolic effects of vitamin D, which is likely to be related to matrix remodeling.

Long fusions to S1 with or without pelvic fixation can induce relevant acute variations in pelvic incidence: a retrospective cohort study of adult spine deformity surgery.

PURPOSE: The purpose of this study is to verify if any changes occur in pelvic incidence (PI) in adult patients undergoing long fusion to sacrum for spine deformity and to describe the effect of fixation to pelvis on these variations. METHODS: We conducted a cross sectional study. Sixty-six adults patients, 87% females (mean ± SD age: 65.1 ± 7.6 years), undergoing fusion from the thoracic spine to the sacrum for adult spine deformity were included. Patients were divided in two different groups: Group A: sacral fixation alone and Group B: sacral fixation plus pelvis fixation. Pre and postoperative standardized full-standing X-rays were analyzed with measurement of: PI, pelvic tilt (PT), lumbar lordosis (LL) and sagittal vertical axis (SVA). RESULTS: A significant effect of time interaction (preoperative to early postoperative; F = 59.93, F = 44.78 and F = 39.87, all p < 0.001) existed for PT, SS and TK in both groups (all, p < 0.001). After adjustment for patients' age (>65 vs. <65 years), a statistically significant increase of PI was observed in patients >65 years (p = 0.006) in Group A between preoperative and postoperative measurements. All patients in Group B exhibited a decrease in PI from preoperative to postoperative. CONCLUSIONS: Older patients undergoing long fusion to the sacrum without pelvic fixation had an increase in PI after surgery. Conversely, pelvic fixation with hips intraoperatively extended has decreased the value of PI from pre- to early postoperative. These changes could be related to degeneration of the sacroiliac joints causing increased rotational mobility and the magnitude of the differences is in the range of clinical relevance.

The effect of case-based discussion of topics with experts on learners' opinions: implications for spinal education and training.

PURPOSE: This investigation aimed to examine the extent to which case-based discussion with experts could influence the audience's opinions on the treatment of patients during a continuing medical education event for spine surgeons. METHODS: We conducted a prospective controlled crossover study of 90 surgeons. During a continuing medical education activity using case-based discussion, quiz questions were used which asked participants (attendants and faculty group) their opinions on the best choices about diagnosis and treatment in a number of cases. No answer was considered correct, but we evaluated the number of participants choosing each specific answer among a number of valid options. Quiz questions were collected with an automated response system at the entry and at the end of each case discussion. Change in participant's opinions was estimated from the change in the preferred answers between the entry and exit quizzes. Chi-square analysis was performed to determine significance. RESULTS: Sixty-two attendants out of eighty three (75%) and six faculties out of twelve (50%) responded to the survey. After the case discussion, 68.2% (p < 0.04, Chi-square test) of the attendants changed their opinion on the appropriate treatment. The faculty answers, however, showed no significant change in opinions regarding the identification of the appropriate treatment. CONCLUSIONS: On the basis of our results, case-based discussion driven by experts, as a form of teaching, has a measurable effect in terms of changes in the learners' opinions.

Ponte osteotomies in thoracic deformities.

Thoracic hyperkyphosis is a sagittal deformity that can cause back pain and neurological impairment, leading to difficulties in maintaining a straight gaze. Sagittal thoracic malalignment has different etiologies and different corrective strategies. An adequate preoperative planning is mandatory to address correctly the surgical treatment, using an appropriate sagittal deformities classification and the rules that relate pelvic parameters to spine curvatures to determine the correction needed to restore a good sagittal alignment. Ponte osteotomies are performed in long non-angular hyperkyphotic thoracic deformities, even if idiopathic scoliosis, rigid deformities or proximal junctional kyphosis after instrumented fusions can benefit from the application of this technique that requires a mobile anterior column for the correction of the deformity. Ponte's is, together with Smith-Petersen osteotomy, a posterior column osteotomy. The magnitude of correction can reach 10° per level if intervertebral discs are still mobile.