Augmented Reality as a Tool to Guide Patient-Specific Templates Placement in Pelvic Resections.

Patient-specific templates (PST) have become a useful tool for guiding osteotomy in complex surgical scenarios such as pelvic resections. The design of the surgical template results in sharper, less jagged resection margins than freehand cuts. However, their correct placement can become difficult in some anatomical regions and cannot be verified during surgery. Conventionally, pelvic resections are performed using Computer Assisted Surgery (CAS), and in recent years Augmented Reality (AR) has been proposed in the literature as an additional tool to support PST placement. This work presents an AR task to simplify and improve the accuracy of the positioning of the template by displaying virtual content. The focus of the work is the creation of the virtual guides displayed during the AR task. The system was validated on a patient-specific phantom designed to provide a realistic setup. Encouraging results have been achieved. The use of the AR simplifies the surgical task and optimizes the correct positioning of the cutting template: an average error of 2.19 mm has been obtained, lower than obtained with state-of-the-art solutions. In addition, supporting PST placement through AR guidance is less time-consuming than the standard procedure that solely relies on anatomical landmarks as reference.

Total hip replacement: a retrospective multicentric analysis on re-intervention rate after single component revision.

Total hip arthroplasty (THA) revision is a procedure consisting in the replacement of a single or multiple implant components and could take place once or more times (re-revision). The aim of this multicentre study is to evaluate the benefits of single component revision in respect of the principles that define implant stability. Two hundred and forty-two patients underwent THA revision at Orthopaedic Clinic of Pisa and Versilia (ITA) from January 2007 to December 2016. We have systematically excluded revisions due to septic or traumatic prosthesis loosening, revisions of both implant components (cotyle and stem) and replacement alone. To evaluate implant stability, we used preoperative X ray and intra-operative mechanical stress tests, applying accredited criteria. Two hundred and twenty-six patients (93%) underwent a single procedure of THA revision: 193 had cotyle replacement and 33 had femoral stem replacement. The remaining 16 (7 %) underwent at least two procedures: 10 of them had consecutive failure of the same component, while the other 6 had revision of the other component after the first procedure. Considering our cases series, we can assert that single component revision is the best choice when no signs of loosening are present on the remaining component. Nevertheless, an accurate evaluation with unanimous radiological criteria and intraoperative testing is essential for the surgeon to choose the most suitable treatment.

Is minimally-invasive spinal surgery a reliable treatment option in symptomatic spinal metastasis?

OBJECTIVE: Up to 70% of patients with cancer are likely to develop spine metastasis. Radiation therapy is the standard of care for painful spinal metastases in absence of unstable or impending fractures. More frequently these patients require open palliative surgery for pain, vertebral collapse and neurological deficits. Minimally Invasive Spine Surgery (MISS) techniques using percutaneous pedicle screw fixation may be considered as an alternative to open surgery in selected cases. MISS techniques are thought to be associated with fewer tissues damages resulting in early pain relief,  they also allow for early mobilization and optimization of function. PATIENTS AND METHODS: From 2011 to 2018, 52 patients affected by spinal metastasis were treated with MISS techniques in Rizzoli Orthopaedic Institute of Bologna and in Cisanello Hospital of Pisa, Italy. All patients underwent percutaneous pedicle screw fixations (PPSF) coupled with mini-decompressions in case it was required by spinal cord compressions. All patients were evaluated pre and post-operatively by Frenkel classification and VAS scores. RESULTS: Mean follow-up time was 19,4 months. Preoperatively, Frankel scores were E in 37 patients, D3 in 6 patients, D2 in 3 cases, D1 in 3 patients, B in one patient and C in two. The Frankel score improved in 10 patients, remained stable in 40 patients and worsened in two patients. Preoperatively, the mean VAS score in 29 patients treated with PPSF procedure with spinal decompression was 7, while postoperatively, it became 5. In 23 patients who underwent only PPSF procedure without spinal decompression mean VAS score was 5, postoperatively it became 3. CONCLUSIONS: In selected cases, MISS surgeries may be considered as a valid alternative to open surgery. Although the efficacy of PPSF has been well documented in trauma or degenerative spine surgery, there is not sufficient literature about MISS techniques in spinal metastasis and further studies are needed to elucidate the most appropriate patient in which this approach could represent the gold standard of treatment.

The sacral chordoma margin.

OBJECTIVE: Aim of the manuscript is to discuss how to improve margins in sacral chordoma. BACKGROUND: Chordoma is a rare neoplasm, arising in half cases from the sacrum, with reported local failure in >50% after surgery. METHODS: A multidisciplinary meeting of the "Chordoma Global Consensus Group" was held in Milan in 2017, focusing on challenges in defining and achieving optimal margins in chordoma with respect to surgery, definitive particle radiation therapy (RT) and medical therapies. This review aims to report on the outcome of the consensus meeting and to provide a summary of the most recent evidence in this field. Possible new ways forward, including on-going international clinical studies, are discussed. RESULTS: En-bloc tumor-sacrum resection is the cornerstone of treatment of primary sacral chordoma, aiming to achieve negative microscopic margins. Radical definitive particle therapy seems to offer a similar outcome compared to surgery, although confirmation in comparative trials is lacking; besides there is still a certain degree of technical variability across institutions, corresponding to different fields of treatment and different tumor coverage. To address some of these questions, a prospective, randomized international study comparing surgery versus definitive high-dose RT is ongoing. Available data do not support the routine use of any medical therapy as (neo)adjuvant/cytoreductive treatment. CONCLUSION: Given the significant influence of margins status on local control in patients with primary localized sacral chordoma, the clear definition of adequate margins and a standard local approach across institutions for both surgery and particle RT is vital for improving the management of these patients.

Mesangiogenic Progenitor Cells and musculoskeletal tissue regeneration: differences between adipose-derived and bone marrow-derived cells?

Mesangiogenic Progenitor cells (MPCs) have been isolated from human bone marrow mononuclear cells (hBM-MNCs) and attracted particular attention for their ability to efficiently differentiate into exponentially growing mesenchymal stromal cells (MSCs) and toward endothelial lineage, suggesting the term "mesangiogenic". Coupling mesengenesis and angiogenis, MPCs has been hypothesized retaining a great tissue regenerative potential in musculoskeletal tissues regeneration. Bone marrow and adipose tissue (AT) represent most promising adult multipotent cell sources attempting to repair bone and cartilage, with controversial results regarding advantages applying BM- or AT-derived cells. As different culture determinants as well as tissue of origins, could strongly affect regenerative potential of cell preparations, we hypothesize that MPCs counterpart could have a role in defining efficacy of applying a cell-based medicinal product in musculoskeletal tissue repair. Here we present convincing data demonstrating that the ex vivo progenitors of MPCs are tissue specific and can be detected exclusively in hBM-MNCs.

Claims in total hip arthroplasty: analysis of the instigating factors, costs and possible solution.

PURPOSE: Over the years, the number of total hip replacements has been steadily increasing. Despite the improvement in surgical results, the number of claims for malpractice is higher. The primary endpoint of this work is to provide an analysis of litigation after hip replacement, to outline what are the instigating causes and costs. The secondary endpoint is to propose a possible preventive strategy for an improved care and a reduction in legal proceedings. MATERIALS AND METHODS: The data of this study were collected from medical and legal files and from professional liability insurance of our institution from January 2005 to December 2016. RESULTS: Out of a total of 4770 THA, 40 claims were received. Peripheral nerve injuries represent the first cause of litigation (37%), followed by infectious complications, leg length discrepancy, metallosis, dislocations of the implant and a case of deep vein thrombosis. From the analysis of the past trial judgment, complications such as nerve lesions and infections are almost always recognized, as a medical error, with a high percentage of claims settled. CONCLUSION: This study shows the necessity of preventive strategies to reduce the higher number of claims for malpractice in total hip arthroplasty. Some complications such as nerve injuries and infection are frequently considered directly dependent on physician's errors. Litigations can be reduced providing evidence of a diligent execution of the surgical procedure and of a proper postoperative management: the correct compilation of a specific informed consent and adequate doctor-patient communication.

Use of autologous bone marrow cells concentrate enriched with platelet-fibrin on extensor mechanism allograft reconstruction for extensor mechanism failure following total knee arthroplasty.

Allografts techniques remain the best reconstructive strategy for chronic extensor mechanism lesions after total knee arthroplasty (3) but outcomes depend strictly on the host tissue-allograft junctions healing. The purpose of this study is to evaluate if modern techniques of adding autologous bone marrow cells concentrate enriched with platelet-rich fibrin, provide better healing of the allograft. We present the case of an 86 years old patient affected by patellar tendon rupture after TKA. A whole extensor mechanism allograft was performed adding a bone marrow cells concentrate enriched with platelet-rich fibrin on the host tissue-allograft junctions. Preoperatively and at each follow-up the value of Knee Society Score and radiographic consolidation signs were recorded. Radiographic controls showed clear signs of consolidation already at 1 months follow-up and a solid fusion at 3 months. This case report describes a valid method to improve healing using a tissue-construct engineered with stem cells and growth factors.

The fifty most cited Italian articles in the orthopaedic literature.

PURPOSES: It is widely known that in Orthopaedics, as in each specialty, the academic influence of an article is also determined by the number of times the article is cited. The aim of this study was to identify the 50 most frequently cited Italian orthopaedics journal articles and to analyse the characteristics that might have made them more citable. METHODS: Science Citation Index Expanded was searched for the 50 most frequently cited Italian orthopaedics journal articles between 1988 and 2013 in the subject category "Orthopaedics". RESULTS: The 50 most frequently cited articles were all published in English and were published in 12 of the 67 journals in the subject category "Orthopaedics" in the Institute for Scientific Information Web Science (Thomson Reuters, New York, New York, USA). One half of the articles were published before 2000 and the other half later. The number of citations ranged from 423 of the first article (mean citation/years 21.15) to 83 of the fiftieth (mean citation/years 16.60). The articles were all categorized under orthopaedic field, but each of them spanned from orthopaedics to a specific sub-specialty. The majority was clinical articles (n = 39), and the most common fields were sport orthopaedic surgery (including arthroscopy and cartilage) (n = 19) and biomechanics (n = 12). CONCLUSIONS: This list of 50 most frequently cited Italian articles is, to our knowledge, significantly important for the general orthopaedic scientific community, particularly for the Italian orthopaedic community. Researchers and doctors may use this work to make their future publications more influential and citable.