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 Positive Side Effect of Anterior Cervical Decompression and Fusion on Axial Neck Pain.

STUDY DESIGN: Observational Cohort Study. OBJECTIVES: This study aims to comprehensively assess the outcomes of anterior cervical spine surgery in patients who have undergone surgical intervention for radiculopathy or myelopathy, with a specific focus on the surgery's impact on axial neck pain. METHODS: Data from an institutional spine surgery registry were analyzed for patients who underwent anterior cervical spine surgery between January 2016 and March 2022. Patient demographics, clinical variables, and outcome measures, including the Neck Disability Index (NDI), numeric rating scales for neck and arm pain (NRS-Neck and NRS-Arm), and 36-Item Short Form Health Survey (SF-36) scores, were collected. Statistical analysis included paired t-tests, chi-squared tests, and multivariate linear regression. RESULTS: Of 257 patients, 156 met the inclusion criteria. Patients showed significant improvement in NDI, NRS-Neck, NRS-Arm, SF-36 (Physical and Mental components), and all changes exceeded the minimum clinically important difference. Multivariate regression revealed that lower preoperative physical and mental component scores and higher preoperative NRS-Neck predicted worse NDI scores at follow-up. CONCLUSIONS: This study underscores that anterior cervical fusion not only effectively alleviates arm pain and disability but also has a positive impact on axial neck pain, which may not be the primary target of surgery. Our findings emphasize the potential benefits of surgical intervention when neck pain coexists with neurologic compression. This contribution adds to the growing body of evidence emphasizing the importance of precise diagnosis and patient selection. Future research, ideally focusing on patients with isolated neck pain, should further explore alternative surgical approaches to enhance treatment options.

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.

Diagnostic Approach and Differences between Spinal Infections and Tumors.

STUDY DESIGN: A systematic review of the literature about differential diagnosis between spine infection and bone tumors of the spine. BACKGROUND AND PURPOSE: The differential diagnosis between spine infection and bone tumors of the spine can be misled by the prevalence of one of the conditions over the other in different areas of the world. A review of the existing literature on suggestive or even pathognomonic imaging aspects of both can be very useful for correctly orientating the diagnosis and deciding the most appropriate area for biopsy. The purpose of our study is to identify which imaging technique is the most reliable to suggest the diagnosis between spine infection and spine bone tumor. METHODS: A primary search on Medline through PubMed distribution was made. We identified five main groups: tuberculous, atypical spinal tuberculosis, pyogenic spondylitis, and neoplastic (primitive and metastatic). For each group, we evaluated the commonest localization, characteristics at CT, CT perfusion, MRI, MRI with Gadolinium, MRI diffusion (DWI) and, in the end, the main features for each group. RESULTS: A total of 602 studies were identified through the database search and a screening by titles and abstracts was performed. After applying inclusion and exclusion criteria, 34 articles were excluded and a total of 22 full-text articles were assessed for eligibility. For each article, the role of CT-scan, CT-perfusion, MRI, MRI with Gadolinium and MRI diffusion (DWI) in distinguishing the most reliable features to suggest the diagnosis of spine infection versus bone tumor/metastasis was collected. CONCLUSION: Definitive differential diagnosis between infection and tumor requires biopsy and culture. The sensitivity and specificity of percutaneous biopsy are 72% and 94%, respectively. Imaging studies can be added to address the diagnosis, but a multidisciplinary discussion with radiologists and nuclear medicine specialists is mandatory.

Oblique, Unilateral, or Bilateral Rods Configurations for Single-Level Interbody Fusion and Posterior Spinal Fixation: A Finite Element Study.

AIM: To compare three different posterior mono-segmental instrumented models with a Lateral Lumbar Interbody Fusion (LLIF) cage in L4-L5 based on finite element (FE) analysis. MATERIAL AND METHODS: Three different configurations of posterior instrumentation were created: 1. Bilateral posterior screws with 2 rods: Bilateral (B); 2. Left posterior rod and left pedicle screws in L4-L5: Unilateral (U); 3. Oblique posterior rod, left pedicle screw in L4, and right pedicle screw in L5: Oblique (O). The models were compared regarding the range of motion (ROM), stresses in the L4 and L5 pedicle screws, and posterior rods. RESULTS: The Oblique and Unilateral models showed a lower decrease in ROM than the Bilateral model (O vs U vs B; 92% vs 95% vs 96%). In the L4 screw, a higher stress level was identified in the O than in the B model. Still, lower if compared to U. In the L5 screw, the highest stress values were observed with the O model in extension and flexion and the U model in lateral bending and axial rotation. The highest stress values for the rods were observed for the O model in extension, flexion, and axial rotation and the U model in lateral bending. CONCLUSION: The FE analysis showed that the three configurations significantly reduced the ROM. The stress analysis identified a substantially higher value for the rod and pedicle screws in oblique or unilateral configuration systems compared to the standard bilateral one. In particular, the oblique configuration has stress properties similar to the unilateral in lateral bending and axial rotation but is significantly higher in flexion-extension.

The burden of preoperative fear-avoidance beliefs in workers after thoracic and lumbar spine surgery: a 2-year follow-up study.

ABSTRACT: Spinal disorders are the main reasons for sick leave and early retirement among the working population in industrialized countries. When "red flags" are present, spine surgery is the treatment of choice. However, the role of psychosocial factors such as fear-avoidance beliefs in spine surgery outcomes is still debated. The study aims to investigate whether patients presenting high or low levels of fear-avoidance thoughts before the spine surgery reported different surgical results and return-to-work rates over 2 years. From an institutional spine surgery registry, workers surgically treated with a preoperative score in the Oswestry Disability Index (ODI) higher than 20/100 and provided ODI questionnaires, return-to-work status at 3-, 6-, 12-, and 24-month follow-ups were analyzed. A total of 1769 patients were stratified according to the work subscale of the Fear-Avoidance Beliefs Questionnaire (FABQ-W) in high fear (FABQ-W ≥ 34/42) or low fear (FABQ-W < 34/42). Multivariate regression was used to search for preoperative factors, which might interact with FABQ-W. The higher-fear group showed a different recovery pattern, with higher levels of disability according to the ODI (total score, absolute change, frequency of clinically relevant change, and disability categories) and lower return-to-work ratios over the 24-month follow-up. High fear, high disability, greater age, female gender, smoking, and worse physical status at baseline were associated with worse ODI outcomes 2 years after the surgery. In summary, fear-avoidance beliefs significantly influence the speed and the entity of surgical outcomes in the working population. However, the contribution of FABQ-W in predicting long-term disability levels was limited.

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.

The aging spine: the effect of vertebral fragility fracture on sagittal alignment.

Our study investigates the relationship, in the aging population, between vertebral fractures, spinal alignment, and quality of life. Kyphotic fractures were related to more significant disability and impaired spinopelvic alignment. The spinal malalignment was strongly associated with fractures in the thoracolumbar junction vertebrae and the absence of powerful compensatory mechanisms as thoracic hypokyphosis and lower lumbar hyperlordosis. INTRODUCTION: In adult spine deformity (ASD), the sagittal imbalance is defined by the deformity in the sagittal plane that causes the need for greater use of muscle strength to maintain an upright static posture or walking. Fragility vertebral fractures (VF) and ASD are frequent causes of spinal morbidity in the elderly. The prevalence of both ASD and VF increases with aging. Although these two clinical conditions insist on the same population, little is known about the interactions between sagittal imbalance and vertebral fracture (VF) deformity. The aim of our work is to examine the associations between vertebral fractures, sagittal alignment, and their impact on the quality of life scores in elderly patients. METHODS: A retrospective cohort study of 110 patients of both sexes, from a spine surgery waiting list, with at least one VF with ≥ 5° of kyphosis and a full-standing X-ray. INDEPENDENT VARIABLES: the presence of VF with kyphotic deformity ≥ 10°, fracture level, degree of kyphosis (deformity) of the fracture, number of fractures, spinopelvic angular parameters, demographic parameters, and scales of evaluation of the health-related quality of life. RESULTS: A total of 110 patients with mean age 73.8 ± 5.2, of which 70 women (63%) were included in the study. Subjects with at least one VF ≥ 10° presented greater disability and an overall worse sagittal spinal alignment (no VF10° vs VF10°: TPA 21.30 ± 11.5 vs 26.51 ± 12.6, p = 0.041) and more disability (no VF10° vs VF10°: ODI 41.91 ± 16.9 vs 54.67 ± 15.8, p < 0.001) than patients with less degree of vertebral deformity. Significant compensatory mechanisms involved the thoracic area and the lower lumbar region. CONCLUSION: Kyphotic VFs were associated with severe alterations of sagittal spine alignment and perceived disability. Subjects with sagittal imbalance have a greater degree of deformity in the thoracolumbar junction area. Thoracic hypokyphosis and lower lumbar hyperlordosis are effective compensatory mechanisms in case of lumbar or thoracic fracture, respectively.

Major complications in extreme lateral interbody fusion access: multicentric study by Italian S.O.L.A.S. group.

PURPOSE: The eXtreme Lateral Interbody Fusion (XLIF) approach has gained increasing importance in the last decade. This multicentric retrospective cohort study aims to assess the incidence of major complications in XLIF procedures performed by experienced surgeons and any relationship between the years of experience in XLIF procedures and the surgeon's rate of severe complications. METHODS: Nine Italian members of the Society of Lateral Access Surgery (SOLAS) have taken part in this study. Each surgeon has declared how many major complications have been observed during his surgical experience and how they were managed. A major complication was defined as an injury that required reoperation, or as a complication, whose sequelae caused functional limitations to the patient after one year postoperatively. Each surgeon was finally asked about his years of experience in spine surgery and XLIF approach. Pearson correlation test was used to evaluate the association between the surgeon's years of experience in XLIF and the rate of major complications; a p-value of last than 0.05 was considered significant. RESULTS: We observed 14 major complications in 1813 XLIF procedures, performed in 1526 patients. The major complications rate was 0.7722%. Ten complications out of fourteen needed a second surgery. Neither cardiac nor respiratory nor renal complications were observed. No significant correlation was found between the surgeon's years of experience in the XLIF procedure and the number of major complications observed. CONCLUSION: XLIF revealed a safe and reliable surgical procedure, with a very low rate of major complications, when performed by an expert spine surgeon.

Perioperative Predictive Factors for Positive Outcomes in Spine Fusion for Adult Deformity Correction.

PURPOSE: Identifying perioperative factors that may influence the outcomes of long spine fusion for the treatment of adult deformity is key for tailored surgical planning and targeted informed consent. The aim of this study was to analyze the association between demographic or perioperative factors and clinical outcomes 2 years after long spine fusion for the treatment of adult deformity. METHODS: This study is a multivariate analysis of retrospectively collected data. All patients who underwent long fusion of the lumbar spine for adult spinal deformity (January 2016-June 2019) were included. The outcomes of interest were the Oswestry disability index (ODI), visual analogic scale (VAS) preoperatively and at 1 and 2 years' follow up, age, body mass index, American Society of Anaesthesiologists (ASA) score, upper and lowest instrumented vertebrae (UIV and LIV, respectively), length of surgery, estimated blood loss, and length of hospital stay. RESULTS: Data from 192 patients were available. The ODI at 2 years correlated weakly to moderately with age (r = 0.4), BMI (r = 0.2), ASA (r = 0.3), and LIV (r = 0.2), and strongly with preoperative ODI (r = 0.6). The leg VAS at 2 years moderately correlated with age (r = 0.3) and BMI (r = 0.3). CONCLUSION: ODI and VAS at 2 years' follow-up had no to little association to preoperative age, health status, LIV, or other peroperative data, but showed a strong correlation with preoperative ODI and pain level.

A Novel Technique for Spondylolysis Repair With Pedicle Screws, Rod and Polyester Band: Case Report With Technical Note and Systematic Literature Review.

STUDY DESIGN: Systematic review and case report. OBJECTIVE: Our study aims to present a new technique using three components to repair the pars defect: pedicle screws, rod and polyester band. Furthermore, we perform a systematic literature review of the previously described techniques. SUMMARY OF BACKGROUND: Spondylolysis is a common condition in children and adolescents. Depending on the severity it may be treated either nonoperatively or surgically. Surgery is required if nonoperative treatment failed to give sustained pain relief. Several surgical techniques have been described. METHODS: The literature review investigates the database (MEDLINE-EMBASE-Cochrane-ScienceDirect) up to May 2019 for studies presenting a surgical technique for spondylolysis.The Screw-Rod-Band (SRB) technique combines the use of pedicle screws, a rod and a polyester band to repair the spondylolysis. The horizontal rod connects the pedicle screws. The polyester band linked to the rod passes below the spinous process to apply compressive forces on the pars. RESULTS: Twenty-one out of 982 studies described a surgical procedure. Eight main different techniques were identified: Isthmic Screw, Wiring, Butterfly-Plate, Hook-Screw Construct, Shaped-Rod, Laminar-Screw, and two combination technique (Lag Screw and Tension Band Fixation and Cortical Screws and Spinous-Process ModularLink). Our technique showed immediate postoperative clinical improvement. No surgical or perisurgical complication occurred. CONCLUSION: The systematic literature review revealed a great number of surgical techniques for the spondylolysis, demonstrating the lack of consensus.SRB technique is an effective and simple treatment for pars fixation. The surgical procedure puts the pars under strong compression. The results are comparable with procedures present in the literature and seems capable to reduce the invasiveness and the risk of neurological injury. LEVEL OF EVIDENCE: 2.

Revision surgery in distal junctional kyphosis.

BACKGROUND: Opposed to proximal junctional kyphosis and proximal junctional failure, their distal equivalents, distal junctional kyphosis and failure (DJK/DJF) have received less attention in the literature. The aim of this article is to provide an overview of the problem of DJK-DJF in different clinical scenarios such as adolescent idiopathic scoliosis (AIS), Scheuermann's kyphosis (SK) and adult deformity surgery and to suggest a strategy for prevention and treatment. METHODS: A narrative review of the literature was conducted to identify the best evidence on the risk factors of the problem. RESULTS: DJK/DJF have been described as a complication of AIS, SK and adult spine deformity (ASD). For AIS and SK, the choice of a lower instrumented vertebra more cranial than the sagittal stable vertebra has shown to increase the incidence of DJK and DJF. For ASD, constructs ending with S1 pedicle screws had a higher incidence of DJK/DJF than those ending distally with S1 pedicle plus iliac screws. CONCLUSION: The proposed strategy of treatment includes restoration of normal sagittal alignment, choice of a distal fixation point stable in the sagittal, coronal and transverse planes, balancing the fusion mass over the distal fixation point and providing solid fixation at the distal end of the construct. 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.

Severe Spinal Surgery Infection and Local Ozone Therapy as Complementary Treatment: A Case Report.

BACKGROUND: Infection is a serious surgical complication that significantly increases morbidity and mortality rates as well as health care expenses. Increased bacterial resistance to antibiotics makes the treatment of such events even more troublesome. OBJECTIVE: To report on a surgical infection case treated with ozone as a complementary therapy. METHODS AND MATERIALS: A female, 65 years old, submitted to a complex surgical procedure for adult kyphotic deformity correction that presented with early postsurgical infection. The patient was treated with revision surgery and antibiotics that improved the condition but were unable to delete the infection. Ozone, in its gaseous form, was injected subcutaneously and paravertebrally twice weekly for 3 weeks. RESULTS: After 3 weeks of treatment, the wound healed completely. Follow-up visits and laboratory exams for up to 1 year after surgery showed no recurrence of infection. CONCLUSIONS: Although just a single case, topical ozone therapy for surgical infections showed promising potential in this specific case.

Supplementary delta-rod configurations provide superior stiffness and reduced rod stress compared to traditional multiple-rod configurations after pedicle subtraction osteotomy: a finite element study.

PURPOSE: The biomechanical performance of conventional multi-rod configurations (satellite rods and accessory rods) in pedicle subtraction osteotomies has been previously studied in vitro and using finite element models (FEM). Delta and delta-cross rods are innovative multi-rod configurations where the rod bends were placed only in its proximal and distal extremities in order to obtain a dorsal translation of the central part of the rod respect to the most angulated area of the main rods. However, the biomechanical properties of the delta and delta-cross rods have not been investigated. This study used FEM to analyze the effect of delta-rod configurations on the stiffness and primary rod stress reduction in multiple-rod constructs after pedicle subtraction osteotomy. METHODS: The global range of motion in the spine and the magnitude and distribution of the von Mises stress in the rods were studied using a spine finite element model described previously. A follower load of 400 N along with moments of 7.5 N in flexion/extension, lateral bending, and axial rotation were tested on the spine model. Initial breakage was created on the rod based on the maximum stress location. The post-breakage models were tested under flexion. RESULTS: Delta and delta-cross rods reduced more range of motion (up to 45% more reduction) and reduced more primary rod stress than other previously tested rod configurations (up to 48% more reduction). After initial rod fracture occurred, delta and delta-cross rods also had less range of motion (up to 23.6% less) and less rod von Mises stress (up to 81.2% less) than other rod configurations did. CONCLUSIONS: Delta and delta-cross rods have better biomechanical performance than satellite rods and accessory rods in pedicle subtraction osteotomies in terms of construct stiffness and rod stress reduction. After the initial rod breakage occurred, the delta and delta-cross rods could minimize the loss of fixation, which have less rod stress and greater residual stiffness than other rod configurations do. Based on this FEA study, delta-rod configurations show more favorable biomechanical behavior than previously described multi-rod configurations. These slides can be retrieved under Electronic Supplementary Material.

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.

Is Propionibacterium acnes related to disc degeneration in adults? A systematic review.

BACKGROUND: The aim of this paper was to systematically review the evidence linking Propionibacterium acnes (P. acnes) with the development of symptomatic degenerative disc disease. EVIDENCE ACQUISITION: Data were obtained from MEDLINE from their inception to October 2015. Two authors independently conducted the searches, extracted data and completed methodological quality assessments. Articles were included if they investigated the presence of P. acnes in symptomatic degenerative disc disease through intra-operative cultural examination. The methodological quality of the studies was evaluated using the Newcastle-Ottawa Scale. EVIDENCE SYNTHESIS: Overall 641 articles were retrieved with 9 cross-sectional studies being included in the review. All selected studies revealed an association between P. acnes and disc degeneration. CONCLUSIONS: This study shows that there is a relationship between P. acnes and development of symptomatic degenerative disc disease. Despite this, we cannot support that P. acnes and development of symptomatic degenerative disc disease due to the low quality of the results according Grading of Recommendations Assessment, Development and Evaluation (GRADE).

Complications in adult spine deformity surgery: a systematic review of the recent literature with reporting of aggregated incidences.

PURPOSE: To review the incidence of perioperative and late complications of surgery for spinal deformity (ASD). METHODS: Review of the literature. We reviewed recent literature in English to investigate the incidence of complications in ASD surgery in the perioperative (≤ 3 months post-operative) and late (> 3 months post-operative) periods. Randomized-controlled trials, non-randomized trials, cohort studies, case-control studies, and case series published in 2005 or later were included. We divided articles according to surgical technique: open procedures (OP), minimally invasive surgery (MIS), and hybrid procedures (HP). Complications were recorded, grouped by surgical technique, and then classified according to a proposed Grading of Incidence of Complications (IOC). RESULTS: Ninety-six publications reporting on 12,168 patients were included; 68 were level IV of evidence studies, 24 were level III, and 4 level II. Perioperative IOC was 26.5% in OP, 36.4% in HP, and 24.2% in MIS. Late IOC was 11.1% in OP, 15.4% in HP, and 14.0% in MIS. IOC was significantly higher for hybrid procedures compared to both open and MIS procedures. CONCLUSIONS: Reported complications of surgery for ASD in the recent literature are frequent (24-36% perioperative plus 11-15% late). Open procedures were the most extensively reported in the literature. Complication rates are similar for OP and MIS. HP presented higher IOC likely due to the combination of OP and MIS respective complications. Small number of studies and heterogeneity in reporting could result in risk of bias in these results. Large-scale registry-based studies can fill this gap in the future. These slides can be retrieved under Electronic Supplementary Material.

Hypercomplex pedicle subtraction osteotomies: definition, early clinical and radiological results and complications.

PURPOSE: To describe hypercomplex pedicle subtraction osteotomies (HyC-PSO) for adult spine deformity with sagittal imbalance in terms of preoperative, intraoperative and postoperative outcomes and complications. METHODS: From a prospective single centre database, patients undergoing PSO between January 2016 and May 2017 were reviewed. HyC-PSO were defined as those in patients with one of the following conditions: sagittal correction > 45° needed at a single level or at 1-3 consecutive vertebrae, more than 60° of total sagittal correction needed and PSO on segments of the spine with congenital deformities. RESULTS: 22 patients were included, 14 had standard PSO (group A) and 8 had HyC-PSO (group B). Significant correction of lumbar lordosis (LL) and pelvic (PT) was noted in both groups (p < 0.01). Operative time was longer in HyC-PSO, 604 min compared to standard PSO, 478 min. A trend versus greater intraoperative blood loss (3837 vs 2285 ml) and greater intraoperative blood infusion (from cell saver plus homologous, 2306 vs 1280 ml) was recorded in HyC-PSO (ns). Patients in group B received significantly more blood units intra and postoperatively (8.25 vs 4.71 units, p = 0.006). Sagittal correction at the PSO level (54.7°-30° to 85°-vs 26.8°-8° to 39°-, p = 0.000) and total sagittal correction (64.5°-50 to 95°-vs 39.8°-20° to 51°-, p = 0.000) were greater in HyC-PSO. PROMs at the last available follow-up did not show significant differences between groups for any of the outcomes analyzed. Complications were similar in both groups. CONCLUSION: This is the first report on hypercomplex pedicle subtraction osteotomies. Hypercomplex PSO describes a subset of clinical scenarios with increased surgical effort that can be measured as longer surgical time and greater blood transfusion requirements. Successful correction of misalignment can be achieved in this specific group of patients, and clinical results and complications profile could be similar to standard PSO procedures.