Minimally invasive surgery versus standard posterior approach in the treatment of adolescent idiopathic scoliosis: a 2-year follow-up retrospective study.

PURPOSE: This is a monocentric retrospective controlled study that compares the safety and efficacy of posterior minimally invasive surgery (MISS) to standard posterior spinal fusion (PSF) surgery in adolescent idiopathic scoliosis (AIS). METHODS: We retrospectively collected 111 patients with Lenke type 1-6 AIS who were treated with MIS (n = 47) or PSF (n = 64) between February 2019 and January 2021 with a 2-year clinical and radiological follow-up. MIS technique was applied via two midline noncontiguous skin incisions ranging from 3 to 7 cm in length, so we obtained the arthrodesis only in the exposed tract, passing the rods below the fascia, avoiding the complete muscular sparing. Values of Cobb angles degrees were collected to study the correction rate of the structural major curve. Postoperative AP direct radiography and preoperative AP direct radiography were compared with the last follow-up examination. Operative time, preoperative hemoglobin (Hb) and second postoperative day Hb, full length of hospitalization, time to achieve verticalization and time to remove the drainage were recorded. NRS medium score was assessed immediately after surgery and during the whole postoperative rehabilitation treatment to estimate pain reduction. Complications were collected postoperatively and throughout the whole follow-up period. RESULTS: There was no significant difference between the two groups in terms of radiographic and clinical features. The correction rates of the structural curve resulted to be not significantly different between MISS and PSF (64.6 ± 11.7 vs 60.9 ± 13.2, p = 0.1292) as well as for the correction rate of the secondary curve between the two compared techniques (59.1 ± 13.2 vs 59.2 ± 12.4, p = 0.9865). The two groups had comparable operative time (210 min vs 215 min). The MIS group had a significantly lower reduction of postoperative Hb in comparison with PSF group (2.8 ± 1.3 mg/dl vs 4.3 ± 1.5 mg/dl, p < 0.0001). The postoperative NRS score was lower in MIS group (1.9 ± 0.8 vs 3.3 ± 1.3). PSF group was observed to have a significantly longer period of hospitalization than MIS (5.2 ± 1.4 days vs 6.3 ± 2.9 days, p = 0.206). Complications were more frequent in PSF group rather than in MFS group. CONCLUSIONS: MISS is a safe and capable alternative to PSF for AIS patients with curves < 70°, with analogue capacity of scoliosis correction and same operative time and with advantages in blood loss, length of stay and postoperative pain.

Factors associated with increased length of stay and risk of complications in 336 patients submitted to spine surgery. The role of a validated capture system (SAVES v2) as a first-line tool to properly face the problem.

PURPOSE: In this study, we analyzed the use of a validated capture system (Spinal Adverse Events Severity system, SAVES V2) as a first non-technical skill to properly face the relevant problem of surgical complications (SCs) and adverse events (AEs) in spinal surgery. METHODS: We retrospectively collected AEs occurring in a tertiary referral center for spine surgery from January 2017 to January 2018 and classified them according to SAVES V2 system. We compared this collection of AEs with a prospective collection performed without any classification system. Univariate and multivariate logistic regression models were used to determined odds ratio (ORs) for selected potential risk factors of AEs and prolonged length of stay. RESULTS: Overall a higher number of AEs was retrospectively recorded using SAVES system compared to the prospective recording without the use of any capture system (97/336 vs 210/336, p < 0.001). The length of stay (LOS) increased in the group of complicated patients for all the procedures examined. In the non-oncological group, LOS was significantly higher for complicated patients compared to uncomplicated patients (F = 44.11, p = 0.0000). Similar results have been obtained in the oncological group of patients. In the multivariate regression model surgical time and postoperative AEs emerged as risk factors for prolonged LOS, while only the presence of previous surgeries was confirmed as risk factor for AEs. CONCLUSION: Considering that the rate of AEs and SCs in spinal surgery is still high despite the improvement of technical skills, we suggest the use of SAVES V2 capture system as a first-line tool to face the problem.

Unraveling the enigma of Adamkiewicz: exploring the prevalence, anatomical variability, and clinical impact in spinal embolization procedures for bone metastases.

BACKGROUND: The artery of Adamkiewicz (AKA) is vital for spinal cord blood supply. Its role in embolization procedures for bone metastases can cause serious complications. We explored its prevalence, anatomical variation, and effect on spinal embolization using N-butyl cyanoacrylate (NBCA) in patients with bone metastases. PURPOSE: To understand the impact and variability of AKA in spinal embolizations in cases of bone metastases to reduce complications and improve patient outcomes. MATERIAL AND METHODS: We examined data from 454 patients who underwent spinal embolization with NBCA between 2009 and 2018. The presence, anastomoses, and tumor features of AKA were assessed via pre-procedure imaging and angiography. Complications were classified per the CIRSE Classification System. RESULTS: AKA was found in 22.8% of patients, predominantly left-sided and originating from T8 to L1. Direct and indirect anastomoses were present in 66.6% and 33.4% of patients, respectively. Extra-compartmental invasion was linked with direct anastomosis (P = 0.004). High-grade complications were rare but included one instance of bilateral lower limb paralysis. Partial embolization was necessary in 22.8% of cases due to AKA. CONCLUSION: The study underscores the need for rigorous preoperative evaluation of AKA origin and anastomoses in patients undergoing spinal embolization for bone metastases. Given the significant presence of AKA and related anastomoses, especially with renal extra-compartmental tumors, caution is advised to reduce complications and optimize patient outcomes. Further research is required for best practice guidelines involving bone metastases and AKA.

Fast-track protocols for patients undergoing spine surgery: a systematic review.

BACKGROUND CONTEXT: Fast-track is an evidence-based multidisciplinary strategy for pre-, intra-, and postoperative management of patients during major surgery. To date, fast-track has not been recognized or accepted in all surgical areas, particularly in orthopedic spine surgery where it still represents a relatively new paradigm. PURPOSE: The aim of this review was provided an evidenced-based assessment of specific interventions, measurement, and associated outcomes linked to enhanced recovery pathways in spine surgery field. METHODS: We conducted a systematic review in three databases from February 2012 to August 2022 to assess the pre-, intra-, and postoperative key elements and the clinical evidence of fast-track protocols as well as specific interventions and associated outcomes, in patients undergoing to spine surgery. RESULTS: We included 57 full-text articles of which most were retrospective. Most common fast-track elements included patient's education, multimodal analgesia, thrombo- and antibiotic prophylaxis, tranexamic acid use, urinary catheter and drainage removal within 24 hours after surgery, and early mobilization and nutrition. All studies demonstrated that these interventions were able to reduce patients' length of stay (LOS) and opioid use. Comparative studies between fast-track and non-fast-track protocols also showed improved pain scores without increasing complication or readmission rates, thus improving patient's satisfaction and functional recovery. CONCLUSIONS: According to the review results, fast-track seems to be a successful tool to reduce LOS, accelerate return of function, minimize postoperative pain, and save costs in spine surgery. However, current studies are mainly on degenerative spine diseases and largely restricted to retrospective studies with non-randomized data, thus multicenter randomized trials comparing fast-track outcomes and implementation are mandatory to confirm its benefit in spine surgery.

Vertebral Bone Marrow Clot towards the Routine Clinical Scenario in Spine Surgeries: What about the Antimicrobial Properties?

Exploring innovative techniques and treatments to improve spinal fusion procedures is a global challenge. Here, we provide a scientific opinion on the ability of a vertebral bone marrow (vBM) clot to provide a local combined delivery system not only of stem cells, signaling biomolecules and anti-inflammatory factors but also of molecules and proteins endowed with antimicrobial properties. This opinion is based on the evaluation of the intrinsic basic properties of the vBM, that contains mesenchymal stem cells (MSCs), and on the coagulation process that led to the conversion of fibrinogen into fibrin fibers that enmesh cells, plasma but above all platelets, to form the clot. We emphasize that vBM clot, being a powerful source of MSCs and platelets, would allow the release of antimicrobial proteins and molecules, mainly cathelicidin LL- 37, hepcidin, kinocidins and cationic host defense peptides, that are per se gifted with direct and/or indirect antimicrobial effects. We additionally highlight that further studies are needed to deepen this knowledge and to propose vBM clot as multifunctional bioscaffold able to target all the main key challenges for spinal fusion surgery.

Gender-Specific Differences in Human Vertebral Bone Marrow Clot.

Recently, our group described the application of vertebral bone marrow (vBMA) clot as a cell therapy strategy for spinal fusion. Its beneficial effects were confirmed in aging-associated processes, but the influence of gender is unknown. In this study, we compared the biological properties of vBMA clots and derived vertebral mesenchymal stem cells (MSCs) from female and male patients undergoing spinal fusion procedures and treated with vBMA clot. We analyzed the expression of growth factors (GFs) in vBMA clots and MSCs as well as morphology, viability, doubling time, markers expression, clonogenicity, differentiation ability, senescence factors, Klotho expression, and HOX and TALE gene profiles from female and male donors. Our findings indicate that vBMA clots and derived MSCs from males had higher expression of GFs and greater osteogenic and chondrogenic potential compared to female patients. Additionally, vBMA-clot-derived MSCs from female and male donors exhibited distinct levels of HOX and TALE gene expression. Specifically, HOXA1, HOXB8, HOXD9, HOXA11, and PBX1 genes were upregulated in MSCs derived from clotted vBMA from male donors. These results demonstrate that vBMA clots can be effectively used for spinal fusion procedures; however, gender-related differences should be taken into consideration when utilizing vBMA-clot-based studies to optimize the design and implementation of this cell therapy strategy in clinical trials.

Primary sclerosing epithelioid fibrosarcoma of the spine: a single-institution experience.

AIMS: To present our experience on spinal sclerosing epithelioid fibrosarcoma (SEF) and review the existing literature pertaining to SEF of the spine. METHODS AND RESULTS: Six cases of spinal SEF were reviewed, and a literature search of all primary SEFs of the spine was performed. All tumours occurred in adults (median age, 41 years) and were located all along the spine, the lumbar vertebrae being the most commonly involved. All patients presented with pain that they had experienced for months. The mean tumour size at diagnosis was 52 mm. Five tumours showed a spectrum of microscopic features consistent with pure SEF, and one showed a hybrid morphology with areas of low-grade fibromyxoid sarcoma. All were diffusely and strongly positive for mucin 4. Two cases were initially misdiagnosed as epithelioid haemangioendothelioma and aggressive chondroblastoma. Fluorescence in-situ hybridisation showed rearrangements of either FUS or EWSR1 in four cases. Reverse transcription polymerase chain reaction showed the presence of FUS-CREB3L1 and EWSR1-CREB3L1 fusion transcripts in two cases and one case, respectively. Of five patients with follow-up data available, two developed one or more local recurrences and three patients had metastatic disease. Distant metastases were mainly to other osseous locations, followed by lungs and lymph nodes. At last follow-up, three patients had died of disease and one was alive with multiple metastases. CONCLUSIONS: SEF is an aggressive sarcoma that can involve the spine. It is important to recognise the spine as the primary location of SEF, in order to avoid misdiagnosis as more common primary spinal neoplasms, which can impact on therapeutic approaches.

Atlantoaxial rotatory subluxation/fixation and Grisel's syndrome in children: clinical and radiological prognostic factors.

Atlantoaxial rotatory subluxation/fixation (AARS/F) is a rare cause of torticollis in children. The aim of our study is to investigate all possible clinical and radiological prognostic factors in children with AARS/F. We retrospectively reviewed all cervical spine CT scans of children with AARS/F treated in our Hospital over the last 15 years. AARS/F was classified according to Fielding and Hawkins classification and C1-C2 rotation-degree was calculated. Moreover, two orthopedic surgeons reviewed all clinical reports of these children. All patients were conservatively treated (cervical traction/neck collar). An early recovery was considered in patients with complete clinical/radiological healing at 3 months follow-up, while a late recovery was considered in patients with disease persistence or relapse at 3 months follow-up or earlier. Fifty-five patients with diagnosis of AARS/F were included in the study (mean age = 8.5 years old - 25F, 30M). In 9/55 subjects (16.4%), a late recovery was observed. The presence of a concomitant infection or inflammation in the head and neck region (Grisel's syndrome) was significantly associated with a late recovery (p < .001). Also, the type of AARS/F (p = .019), according to the Fielding and Hawkins classification, and C1-C2 rotation-degree (p = .027) were significantly correlated with the recovery time.Conclusion: In patients with AARS/F, the presence of a concomitant infection/inflammation in the head and neck region is the most important prognostic factor and it is associated with a late recovery. The Fielding and Hawkins classification and C1-C2 rotation-degree well correlate with patients' recovery time. What is Known: • Atlantoaxial rotatory subluxation/fixation (AARS/F) is a rare cause of torticollis in children and CT is the most useful imaging tool for diagnosis and classification of AARS/F. • Conservative treatments are effective in the majority of pediatric patients with AARS/F. What is New: • The presence of a concomitant infection/inflammation in the head and neck region associated with AARS/F (Grisel's syndrome) is the most important prognostic factor and it is associated with a late recovery. • C1-C2 rotation-degrees, as well as Fielding and Hawkins classification system, well correlate with patients' recovery time.

The role of percutaneous transarterial embolization in the management of spinal bone tumors: a literature review.

PURPOSE: Spinal bone tumors include a heterogeneous broad of primary or metastatic lesions that may present as incidental findings or manifest with painful symptoms and pathological fractures. Optimal management of spine bone lesions is often difficult and treatment algorithms are usually solidly based on surgery. We aimed to evaluate the contribution of trans-arterial embolization in this field, with particular attention to the procedure efficacy, technical difficulties and complications. METHODS: We present a literature review on the role of trans-arterial embolization in the management of spinal bone tumors, both primary and metastatic, evaluating its contribution as preoperative treatment, palliative procedure and standalone curative strategy. RESULTS: Trans-arterial embolization provides an important contribution to reducing surgery hemorrhagic risks, offering a better visualization of the operating field, and possibly increasing tumor susceptibility to chemotherapy or radiation therapy. Nonetheless, it plays an important part in pain palliation, with the unquestionable advantage of being easily repeatable in case of necessity. Its curative role as a standalone therapy is still subject of debate, and at the present time, satisfactory results have been recorded only in the treatment of aneurysmal bone cysts. CONCLUSION: Percutaneous trans-arterial embolization has established as a highly useful minimally invasive procedure in the management of spinal bone lesions, particularly as adjuvant preoperative therapy and palliative treatment.

Histological examination of a retrieved custom-made 3D-printed titanium vertebra : Do the fine details obtained by additive manufacturing really promote osteointegration?

PURPOSE: In the present report it is described the design, the manufacturing and the successful surgical implant of one of the first 3D custom titanium vertebra realized with Additive Manufacturing technique and its use for the spinal reconstruction after en-bloc resection for primary osteogenic sarcoma. METHODS: Clinical case presentation and the design of the 3D custom titanium vertebra was reported. It was also described the complex procedures adopted to evaluate the retrieved device from the histological point of view, as a tumor relapse hit the patient, one year after the reconstruction procedure. RESULTS: The histological evaluation confirmed that the resection technique exerts an important role in promoting bone formation: vertebral body osteotomies favored the reconstruction procedure and maximized the contact area between host bone/vertebral prosthesis thus favoring the bone tissue penetration and device colonization. CONCLUSION: The sharing of these results is very important as they represent the starting point for improving the knowledge starting from the evidence obtained in a challenging clinical condition and with post-operative treatments that could be never reproduced in preclinical model.

Feasibility of achieving planned surgical margins in primary spine tumor: a PTRON study.

OBJECTIVE: Oncological resection of primary spine tumors is associated with lower recurrence rates. However, even in the most experienced hands, the execution of a meticulously drafted plan sometimes fails. The objectives of this study were to determine how successful surgical teams are at achieving planned surgical margins and how successful surgeons are in intraoperatively assessing tumor margins. The secondary objective was to identify factors associated with successful execution of planned resection. METHODS: The Primary Tumor Research and Outcomes Network (PTRON) is a multicenter international prospective registry for the management of primary tumors of the spine. Using this registry, the authors compared 1) the planned surgical margin and 2) the intraoperative assessment of the margin by the surgeon with the postoperative assessment of the margin by the pathologist. Univariate analysis was used to assess whether factors such as histology, size, location, previous radiotherapy, and revision surgery were associated with successful execution of the planned margins. RESULTS: Three hundred patients were included. The surgical plan was successfully achieved in 224 (74.7%) patients. The surgeon correctly assessed the intraoperative margins, as reported in the final assessment by the pathologist, in 239 (79.7%) patients. On univariate analysis, no factor had a statistically significant influence on successful achievement of planned margins. CONCLUSIONS: In high-volume cancer centers around the world, planned surgical margins can be achieved in approximately 75% of cases. The morbidity of the proposed intervention must be balanced with the expected success rate in order to optimize patient management and surgical decision-making.

Diagnostic accuracy of positron emission tomography/computed tomography-driven biopsy for the diagnosis of lymphoma.

INTRODUCTION: Biopsy of affected tissue is required for lymphoma diagnosis and to plan treatment. Open incisional biopsy is traditionally the method of choice. Nevertheless, it requires hospitalization, availability of an operating room, and sometimes general anesthesia, and it is associated with several drawbacks. Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) can be potentially used to drive biopsy to the most metabolically active area within a lymph node or extranodal masses. METHODS: A study of diagnostic accuracy was conducted to assess the performance of a PET-driven needle biopsy in patients with suspect active lymphoma. RESULTS: Overall, 99 procedures have been performed: three (3.0%) were interrupted because of pain but were successfully repeated in two cases. Median SUVmax of target lesions was 10.7. In 84/96 cases, the tissue was considered adequate to formulate a diagnosis (diagnostic yield of 87.5%) and to guide the following clinical decision. The target specimen was a lymph node in 60 cases and an extranodal site in 36. No serious adverse events occurred. The sensitivity of this procedure was 96%, with a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 75%. CONCLUSION: Patients can benefit from a minimally invasive procedure which allows a timely and accurate diagnosis of lymphoma at onset or relapse.

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.

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.

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.

Spinal surgery complications: an unsolved problem-Is the World Health Organization Safety Surgical Checklist an useful tool to reduce them?

PURPOSE: To investigate whether the World Health Organization Safety Surgical Checklist (SSC) is an effective tool to reduce complications in spinal surgery. METHODS: We retrospectively evaluated the clinical and radiological charts prospectively collected from patients who underwent a spinal surgery procedure from January 2010 to December 2012. The aim of this study was to compare the incidence of complications between two periods, from January to December 2010 (without checklist) and from January 2011 and December 2012 (with checklist), in order to assess the checklist's effectiveness. RESULTS: The sample size was 917 patients with an average of 30-month follow-up. The mean age was 52.88 years. The majority of procedures were performed for oncological diseases (54.4%) and degenerative diseases (39.8%). In total, 159 complications were detected (17.3%). The overall incidence of complications for trauma, infectious pathology, oncology, and degenerative disease was 22.2%, 19.2%, 18.4%, and 15.3%, respectively. No correlation was observed between the type of pathology and the complication incidence. We observed a reduction in the overall incidence of complications following the introduction of the SSC: In 2010 without checklist, the incidence of complications was 24.2%, while in 2011 and 2012, following the checklist introduction, the incidence of complications was 16.7% and 11.7%, respectively (mean 14.2%). CONCLUSIONS: The SSC seems to be an effective tool to reduce complications in spinal surgery. We propose to extend the use of checklist system also to the preoperative and postoperative phases in order to further reduce the incidence of complications. These slides can be retrieved under Electronic Supplementary Material.

Effect of strontium substituted ß-TCP associated to mesenchymal stem cells from bone marrow and adipose tissue on spinal fusion in healthy and ovariectomized rat.

Despite alternatives to autogenous bone graft for spinal fusion have been investigated, it has been shown that osteoconductive materials alone do not give a rate of fusion comparable with autogenous bone. This study analyzed a strontium substituted ß-tricalcium phosphate (Sr-ßTCP) associated with syngeneic, unexpanded, and undifferentiated mesenchymal stem cells from bone marrow (BMSC) or adipose tissue (ADSC) as a new tissue engineering approach for spinal fusion procedures. A posterolateral fusion was performed in 15 ovariectomized (OVX) and 15 sham-operated (SHAM) Inbred rats. Both SHAM and OVX animals were divided into three groups: Sr-ßTCP, Sr-ßTCP + BMCSs, and Sr-ßTCP + ADSCs. Animals were euthanized 8 weeks after surgery and the spines evaluated by manual palpation, micro-CT, and histology. For both SHAM and OVX animals, the fusion tissue in the Sr-ßTCP + BMSCs group was more solid. This effect was significantly higher in OVX animals by comparing the Sr-ßTCP + BMCSs group with Sr-ßTCP + ADSCs. Radiographical score, based on micro-CT 2D image, highlighted that the Sr-ßTCP + BMCSs group presented a similar fusion to Sr-ßTCP and higher than Sr-ßTCP + ADSCs in both SHAM and OVX animals. Micro-CT 3D parameters did not show significant differences among groups. Histological score showed significantly higher fusion in Sr-ßTCP + BMSCs group than Sr-ßTCP and Sr-ßTCP + ADSCs, for both SHAM and OVX animals. In conclusion, our results suggest that addition of BMSCs to a Sr-ßTCP improve bone formation and fusion, both in osteoporotic and nonosteoporotic animal, whereas spinal fusion is not enhanced in rats treated with Sr-ßTCP + ADSCs. Thus, for conducting cells therapy in spinal surgery BMSCs still seems to be a better choice compared with ADSCs.

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.

Bone marrow aspirate clot: A technical complication or a smart approach for musculoskeletal tissue regeneration?

One of the methods employed to improve healing of damaged tissues is the use of cellular based therapies. A number of regenerative medicine based strategies, from in vitro expanded mesenchymal stem cells (MSCs) to "one-step" procedures using bone marrow (BM) in toto (BM aspirate; BMA) or BM concentrate (BMC), have been developed. Recently, orthopedic researchers focused their attention on the clinical therapeutic potential of BMC and BMA for musculoskeletal regeneration. BMA is reported as an excellent source of cells and growth factors. However, the quality of BM harvest and aspirate is extremely technique-dependent and, due to the presence of megakaryocytes and platelets, BMA is prone to clot. BMA clot formation is usually considered a complication hampering the procedures on both BMC preparation and MSC expansion. Therefore, different protocols have been developed to avoid and/or degrade clots. However, from a biological point of view there is a strong rationale for the use of BMA clot for tissue engineering strategies. This descriptive systematic literature review summarizes preclinical and clinical studies dealing the use of BMA clot for orthopedic procedures and provided some evidence supporting its use as a cell based therapy for cartilage and bone regeneration. Despite these results, there are still few preclinical and clinical studies that carefully evaluate the safety and efficacy of BMA clot in orthopedic procedures. Thus, implementing biological knowledge and both preclinical and clinical studies could help researchers and clinicians to understand if BMA clots can really be considered a possible therapeutic tool.