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.

Use of Statins and Hip Fracture Risk: a Case-Control Study.

PURPOSE OF THE STUDY To evaluate a possible association between hip fracture and statin use. MATERIAL AND METHODS In this case-control study we compared the use of statins between two groups of 210 patients: the first group (case group) included patients hospitalized for hip fractures while the second group (control group) included patients who did not suffer femur bone injuries. The two groups were matched for age, sex, year of hospitalization and possible confounding factors. Inside the group of cases, we also evaluated the differences in terms of fracture type, presence of previous fragility fracture and mortality between statin users and non-users. RESULTS The use of statins was most common among patients without previous fractures (OR=0.54; 95% CI=0.33-0.89; p=0.0138), especially in older patients (OR=0.40; 95% CI=0.22-0.76). We did not find any significant difference in statin intake between men and women in the control group. In the case group, those who did not use statins were more likely to undergo a medial hip fracture (28.5% vs 16.1%). Patients from case group also presented a greater mortality (27.9% vs 19.35%) and an higher percentage of previous hip fractures (20.11% vs 9.7%). However, they didn't presented a significant higher rate of fragility fractures in other sites. DISCUSSION AND CONCLUSIONS Our study suggests a reduced hip fracture risk, especially in cases aged 80 or more, a different fracture pattern (lower percentage of medial fractures) and a reduced mortality at 9 months in patients treated with HMG-CoA reductase inhibitors, confirming the previous evidences reported in literature. Key words: statin, hip fractures, fracture risk, osteoporosis.

Identification of recurrent genetic patterns from targeted sequencing panels with advanced data science: a case-study on sporadic and genetic neurodegenerative diseases.

BACKGROUND: Targeted Next Generation Sequencing is a common and powerful approach used in both clinical and research settings. However, at present, a large fraction of the acquired genetic information is not used since pathogenicity cannot be assessed for most variants. Further complicating this scenario is the increasingly frequent description of a poli/oligogenic pattern of inheritance showing the contribution of multiple variants in increasing disease risk. We present an approach in which the entire genetic information provided by target sequencing is transformed into binary data on which we performed statistical, machine learning, and network analyses to extract all valuable information from the entire genetic profile. To test this approach and unbiasedly explore the presence of recurrent genetic patterns, we studied a cohort of 112 patients affected either by genetic Creutzfeldt-Jakob (CJD) disease caused by two mutations in the PRNP gene (p.E200K and p.V210I) with different penetrance or by sporadic Alzheimer disease (sAD). RESULTS: Unsupervised methods can identify functionally relevant sources of variation in the data, like haplogroups and polymorphisms that do not follow Hardy-Weinberg equilibrium, such as the NOTCH3 rs11670823 (c.3837 + 21 T > A). Supervised classifiers can recognize clinical phenotypes with high accuracy based on the mutational profile of patients. In addition, we found a similar alteration of allele frequencies compared the European population in sporadic patients and in V210I-CJD, a poorly penetrant PRNP mutation, and sAD, suggesting shared oligogenic patterns in different types of dementia. Pathway enrichment and protein-protein interaction network revealed different altered pathways between the two PRNP mutations. CONCLUSIONS: We propose this workflow as a possible approach to gain deeper insights into the genetic information derived from target sequencing, to identify recurrent genetic patterns and improve the understanding of complex diseases. This work could also represent a possible starting point of a predictive tool for personalized medicine and advanced diagnostic applications.

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.

Giant cell tumor of extremities, surgical treatment and local adjuvants: which is the most effective?

Giant cell tumour (GCT) represents 5% of all primitive bone tumours. Standard surgical treatment of GCT includes intralesional excision or segmental resection. Curettage has a higher recurrence rate (10-25% in stage 2 or 3 but does preserve adjacent joint function. The use of local adjuvants such as phenol, alcohol, H2O2, Argon or cement may decrease recurrence rate, yet which local adjuvant works best is still, to this day, controversial. A series of 109 patients with GCT of the extremity, surgical treated in a single Institution from 2016 to 2018, were analysed in a retrospective study. The purpose of our study was to report the incidence of recurrence rate in patients with GCT of limbs treated in a single institution with different local adjuvants. The results of the present study suggests that curettage in association to cryoablation seems to reduce the recurrence rate compared to "classic" local adjuvants.

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.

Monthly Intramuscular Neridronate for the Treatment of Postmenopausal Osteoporosis: Results of a 6-Year Prospective Italian Study.

PURPOSE: Oral bisphosphonates (BPs) are the most commonly used medications for osteoporosis (OP), but their poor gastrointestinal (GI) absorption and tolerance hamper compliance. Intramuscular (IM) neridronate (NE), an amino-BP, is an easy-to-administer, effective, and safe alternative to oral BPs. We assessed the 6-year effects of monthly IM NE on bone mineral density (BMD) and bone turnover biomarkers (BMs) in postmenopausal OP. METHODS: This single-center, prospective study enrolled postmenopausal osteoporotic outpatients with gastric intolerance to BPs (based on Tuscany Region's law GRT n. 836 20/10/2008). They received 25 mg IM NE once a month (with vitamin D and calcium if necessary) for 6 years. BMD was evaluated at lumbar spine (L1-L4), femoral neck (FN), and total femur (TF) at baseline (BL) and every 12 months afterwards. At BL, month 3, and every 12 months after BL, total and ionized calcium, vitamin D, parathyroid hormone 1-84, bone alkaline phosphatase (BALP), osteocalcin, and N- and C-terminal telopeptides were assayed. RESULTS: Overall, 60 women (mean age: 62.3 ± 7.5 years) received monthly IM NE for 6 years, with vitamin D and calcium supplementation in 81.3% of cases. Compared to BL, BMD increased significantly already after 1 year at all sites (4.5 ± 0.9% for L1-L4, 4.5 ± 0.8% for TF, and 2.1 ± 0.6% for FN, P ≤ 0.05), and the changes were maintained over time, whereas FN further improved up to year 3 and remained stable afterwards (P ≤ 0.05). All BMs, except for total calcium and BALP, progressively decreased over time (P ≤ 0.05). No fractures and significant adverse events were reported. CONCLUSION: The monthly administration of IM NE represents a manageable and effective option, in terms of BMD and bone BM improvement, for the long-term treatment of postmenopausal OP women with gastric intolerance to BPs. This trial is registered with ClinicalTrials.gov Identifier: NCT03699150.

Cerebral Mitochondrial Microangiopathy Leads to Leukoencephalopathy in Mitochondrial Neurogastrointestinal Encephalopathy.

BACKGROUND AND PURPOSE: Mitochondrial neurogastrointestinal encephalopathy is a rare disorder due to recessive mutations in the thymidine phosphorylase gene, encoding thymidine phosphorylase protein required for mitochondrial DNA replication. Clinical manifestations include gastrointestinal dysmotility and diffuse asymptomatic leukoencephalopathy. This study aimed to elucidate the mechanisms underlying brain leukoencephalopathy in patients with mitochondrial neurogastrointestinal encephalopathy by correlating multimodal neuroradiologic features to postmortem pathology. MATERIALS AND METHODS: Seven patients underwent brain MR imaging, including single-voxel proton MR spectroscopy and diffusion imaging. Absolute concentrations of metabolites calculated by acquiring unsuppressed water spectra at multiple TEs, along with diffusion metrics based on the tensor model, were compared with those of healthy controls using unpaired t tests in multiple white matters regions. Brain postmortem histologic, immunohistochemical, and molecular analyses were performed in 1 patient. RESULTS: All patients showed bilateral and nearly symmetric cerebral white matter hyperintensities on T2-weighted images, extending to the cerebellar white matter and brain stem in 4. White matter, N-acetylaspartate, creatine, and choline concentrations were significantly reduced compared with those in controls, with a prominent increase in the radial water diffusivity component. At postmortem examination, severe fibrosis of brain vessel smooth muscle was evident, along with mitochondrial DNA replication depletion in brain and vascular smooth-muscle and endothelial cells, without neuronal loss, myelin damage, or gliosis. Prominent periependymal cytochrome C oxidase deficiency was also observed. CONCLUSIONS: Vascular functional and histologic alterations account for leukoencephalopathy in mitochondrial neurogastrointestinal encephalopathy. Thymidine toxicity and mitochondrial DNA replication depletion may induce microangiopathy and blood-brain-barrier dysfunction, leading to increased water content in the white matter. Periependymal cytochrome C oxidase deficiency could explain prominent periventricular impairment.

Regional pattern of microgliosis in sporadic Creutzfeldt-Jakob disease in relation to phenotypic variants and disease progression.

AIMS: The aim of this study was to describe the regional profiles of microglial activation in sporadic Creutzfeldt-Jakob disease (sCJD) subtypes and analyse the influence of prion strain, disease duration and codon 129 genotype. METHODS: We studied the amount/severity and distribution of activated microglia, protease-resistant prion protein (PrPSc ) spongiform change, and astrogliosis in eight regions of 57 brains, representative of the entire spectrum of sCJD subtypes. RESULTS: In each individual subtype, the regional extent and distribution of microgliosis significantly correlated with PrPSc deposition and spongiform change, leading to subtype-specific 'lesion profiles'. However, large differences in the ratio between PrPSc load or the score of spongiform change and microglial activation were seen among disease subtypes. Most significantly, atypical sCJD subtypes such as VV1 and MM2T showed a degree of microglial activation comparable to other disease variants despite the relatively low PrPSc deposition and the less severe spongiform change. Moreover, the mean microglial total load was significantly higher in subtype MM1 than in MM2C, whereas the opposite was true for the PrPSc and spongiform change total loads. Finally, some sCJD subtypes showed distinctive regional cerebellar profiles of microgliosis characterized by a high granular/molecular layer ratio (MV2K) and/or a predominant involvement of white matter (MVK and MM2T). CONCLUSIONS: Microglial activation is an early event in sCJD pathogenesis and is strongly influenced by prion strain, PRNP codon 129 genotype and disease duration. Microglial lesion profiling, by highlighting strain-specific properties of prions, contributes to prion strain characterization and classification of human prion diseases, and represents a valid support to molecular and histopathologic typing.

A local anesthesia without tourniquet for distal fibula hardware removal after open reduction and internal fixation: the safe use of epinephrine in the foot. A randomized clinical study.

Hardware removal after surgical treatment fracture is one of the most common procedures in orthopaedic daily activity. A percentage from 14.5 to 21 of total removal involves the ankle joint. Trying to reduce the important socio-economic impact of this surgical procedure, we thought to perform it using the Wide Awake Local Anaesthesia Without Tourniquet (WALANT), a particular technique presented by D. Lalonde that associated a local anaesthetic drug with epinephrine in order to obtain an effective haemostatic effect despite the lack of a tourniquet. Nowadays, the WALANT efficiency and safety in hand surgery is widely demonstrated in literature but there are no data about its use in lower limb extremity surgeries. Authors performed a randomized study with 60 patients whom underwent distal fibula hardware removal between 2014 and 2016; they were divided into two groups: Group A under loco-regional anaesthesia with tourniquet and Group B under WALANT. We did not find significant differences in term of maximum pain level felt during the anaesthesiologic and surgical procedure. However, the use of WALANT significantly reduced post-operative pain levels. The WALANT procedures also reduced the number of hospitalization days. No differences in term of post-operative complication rates were found. In conclusion, the WALANT can be considered as a suitable option for distal fibula hardware removal in selected patients; it shows important clinical and economic advantages compared to the traditional loco-regional anaesthesia with tourniquet. This study also lays the foundation for the use of the WALANT beyond the field of hand surgery only.

Cryotherapy efficacy and safety as local therapy in surgical treatment of musculoskeletal tumours. A retrospective case series of 143 patients.

Cryotherapy, also called Cryoablation (CA), is a technique that provides a local treatment to various pathological conditions. In Musculoskeletal tumours management, Cryoablation is well accepted and validated as a treatment in palliative cures for metastatic patients. Recently, CA has been proposed also as an alternative to radiofrequency ablation in osteoid osteoma and other benign tumour treatment with promising results. Cryotherapy with argon ice-balls as local adjuvant in open surgery is a tool that can provide enlargement of surgical margins if used properly. There is still not enough evidence supporting use of cryotherapy as local adjuvant in Musculoskeletal open surgery as the series cited above are very small and there is no comparative RCT between local adjuvant therapies including CA. One-hundred-and-eighty-three patients were treated with Cryoablation from 2000 and 2018 in the Musculoskeletal Tumours Surgery Unit of Careggi (Florence) and the University 2nd Clinic of Pisa. In our study group, 38 patients (26.6%) were affected by bone metastasis, 16 patients (11.1%) by aneurismal bone cysts or angiomas, 22 patients (15.4%) by low-grade malignant musculoskeletal tumours, 2 patients (1,4%) by fibromatosis, 63 patients (44.1%) by benign musculoskeletal tumours (principally Giant Cell Tumours-GCT) and 2 patients (1.4%) by Osteosarcomas. In 125 cases (87.4%), CA has been used as an adjuvant therapy, in 12 cases (8.4%) as a percutaneous ablation therapy and in 6 cases (4.2%) as adjuvant to remove tumoral lesions 'en bloc' or as a 'poor technique' for its sterilizing effect on previously resected bones. Mean follow-up was 10 years. Twenty-three patients (16%) were classified as Alive with Disease (AWD) due to local recurrence or tumour progression (14 metastases, 5 low-grade malignant bone tumours, 4 Giant Cell Tumours). Eight patients died due to the disease (6 metastases, 2 osteosarcomas), while 1 died from leukaemia. One-hundred-and-eleven patients (78%) were classified as Continues Disease Free (CDF). All patients reported decrease in pain-related symptoms after surgery and all surgeons reported better control of blood loss. Three cases (2%) of local skin necrosis or wound dehiscence were reported. No local recurrences were reported after fibromatosis ablation. Our results confirm that CA could be considered as a safe and effective technique to treat various conditions as adjuvant and palliative therapy. In particular, in open surgery, cryotherapy as an adjuvant treatment could lead to very low rates of recurrence in locally aggressive tumours like Giant Cell Tumours. These results could be generalized but a better understanding about indications and outcomes can be reached studying CA in specific populations with comparation to other adjuvant techniques.

Polymethylmethacrylate-augmented fenestreted pedicle-screw fixation in low bone quality patients: a case series and literature review.

The use of pedicle screws in low bone quality patients implicates risks of secondary implant loosening for grip lack. In fact, the result is a reduced mechanical stability at bone-screw interface and consequently an increased chance of pullout and hardware failure. Augmentation techniques have been described for many years and fenestrated screws that allow cement injection is one of them. This is a retrospective observational study of patients treated at our department with polymethylmethacrylate- (PMMA) augmented fenestrated screws. Indications for posterior instrumentation were traumatic fracture in osteoporotic spine, oncological disease, post-traumatic deformity, degenerative disease, revision surgery and sickle cell disease fractures. Implant stability was evaluated with X-Rays and CT scan performed 3 days after surgery and every 3 months during the follow-up. Accuracy of screw placement was evaluated with Heary classification. Fifty-three surgical treatments in 52 patients were performed and 247 PMMA augmented fenestrated screws were placed. According to the Heary classification, 96.21% resulted Grade I, 1.8% Grade II, 2% Grade IV. A total of 17 complications occurred. Fenestrated screw augmentation should be performed in selected patients in whom the bone quality is insufficient to guarantee implant stability. These screws may result useful in complex cases as revision surgeries, osteoporosis and tumour affections where bone quality is highly compromised.

Bone cement implantation syndrome: a thromboelastographic study of the effect of bone cement on coagulation.

Bone cement implantation syndrome (BCIS) is a rare form of intraoperative pulmonary embolism (EP) that occurs during cementation. It can be explained by two main theories: the monomer mediated model and the mechanic model. Our goal is to evaluate thromboelastographic changes in patients undergoing surgery for femoral neck fractures. We recruited 32 patients with a femoral neck fracture. The average age was 81.91 years (range 62-95). The patients were divided in two different groups: cemented hip arthroplasty (CC, 13 patients) and other surgical non-cemented techniques (SC, non-cemented hip arthroplasty, osteosynthesis). The coagulation was evaluated by TEG in the early pre-operatory (time A) and post-operatory (time B), both on native blood and on blood added with Heparinase. We used the t-test to compare the differences between the two groups. The coagulation index CI was modified on hypercoagulability by surgery in both groups, but without statistical significance between the two groups (p>0.05). R parameter decreases between time A and time B in the same way in both groups (p>0.05). Parameter MA had no major variations between time A and B, without statistical significance (p>0.05). From our study it is evident that although the surgery would result in a change in the layout of the TEG toward hypercoagulability, this is similar both in cemented and non-cemented surgical interventions for femoral neck fractures in elderly patients. An altered coagulation does not appear to be the cause or a factor in determining the BCIS.

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.

Correlation between gamma glutamyltransferase fractions and bone quality.

Gamma-glutamyltransferase (GGT) has been recently identified as a bone-resorbing factor. The aim of this study was to investigate the association between plasma GGT fractions levels and bone quality. Plasma GGT fractions were analysed by gel-filtration chromatography. Bone quality was established quantitatively by two micro-CT derived microarchitectural parameters: the BV/TV (mineralised bone volume/total volume), and the SMI (structure model index) that describes the rod-like (low resistant) or plate-like (high-resistant) shape of bone trabeculae. We enrolled 93 patients hospitalised for elective total hip replacement (group Arthrosis, n=46) or for proximal femoral fracture (group Fracture, n=47). Patients within the first quartile of BV/TV (Q1, osteoporotic patients, n=6) showed higher levels of b-GGT fraction [median (min-max): 3.37 (1.42­6.81)] compared to patients with normal bone density (fourth quartile Q4, n=10; 1.40 (0.83­4.36); p=0.0393]. Also, according to SMI, b-GGT value was higher in the subgroup with bone fragility [Q1, n=8: 1.36 (0.43­4.36); Q4, n=8: 5.10 (1.4 ­7.60); p=0.0117]. In conclusion, patients characterised by fragile bone structure showed specifically higher levels of plasma b-GGT activity thus suggesting fractional GGT analysis as a possible biomarker in the diagnosis of osteoporosis.

Complications and survival of megaprostheses after resection of bone metastases.

Treatment of bone metastases is often palliative, aiming at pain control and stabilization or prevention of pathological fractures. However, a complete resection with healing purposes can be performed in selected cases. The aim of our work was to evaluate the survival of megaprostheses used for reconstruction after bone metastases. Between January 2001 and March 2015, we implanted 169 Megasystem-C® (Waldemar LINK® GmbH & Co. KG, Hamburg, Germany) after bone metastasis resection. Patients, 95 females and 74 males, were operated at an average age of 61 (12-87) years for proximal femoral resection in 135 (79.9%) cases, distal femur in 24 (14.2%), proximal tibia in 6 (3.6%), total femur in 3 (1.8%) and intercalary femur in 1 (0.6%). Mostly, breast cancer metastases (30.8%), kidney (17.8%) and lung (14.2%) were treated. At an average follow-up of 21 (1-150) months, we found a 99.4% overall limb salvage and a 96.1% overall survival rate at 1 year, 92.8% at 2 years, and 86.8% at 5 and 10 years. We found 9 (5.3%) mobilization cases of the proximal femoral implant, 3 needed surgical reduction; 2 (1.2%) cases of aseptic loosening of the prosthetic stem; 2 (1.2%) periprotetic infection cases, one requiring a 2-stage revision. Few literature studies have evaluated the survival of megaprosthetic implant in the treatment of bone metastases. Our data show how in this specific context the rate of complications is significantly lower than expected in general orthopedic orthopedic surgery. The use of modular prostheses is a valid reconstructive strategy after bone metastasis resection in selected patients. The rate of short-term complications is exceptionally low; further studies will have to confirm this in the longer term.