Osteoarthritis is a whole-joint disease and its pathogenesis remains poorly understood. Recentevidence proposed the importance of the innate immune system as trigger of synovium inflammationfollowing the degeneration of cartilage. Moreover, synovial mast cells (MCs) might be correlated withpain and disability reported by patients. Anti IgE therapy represents a new class of MCs stabilizingagent, licensed for people with asthma and chronic urticaria. Therefore, we studied if the stabilizingeffect of anti IgE would improve the pain and disability in patients affected by knee osteoarthritis andatopic disease. This pilot study provides the first evidence that anti IgE treatment induces a short-termclinical improvement supporting the role of MCs in osteoarthritis.
A successful Total Knee Arthroplasty (TKA) requires stability, but rarely in primary TKA, a prosthesiswith more constraint than a posterior-stabilizer (PS) is necessary. In patients with severe varus/valgusdeformities with incompetent collateral ligaments or in knees that cannot be adequately balanced afterligaments release, a total-stabilizer (TS) prosthesis may be required. The purpose of our retrospectivestudy is to evaluate clinical and radiographic outcomes at short mid-term follow-up in patients treatedwith a TS TKA. Between January 2013 and August 2016, 36 patients (38 knees) were treated with StrykerTriathlon TS cemented implants. Clinical and radiographic evaluation were performed preoperativelyand postoperatively at 1 month, 3 months, 6 months, 1 year and at 1-year intervals thereafter. At finalfollow-up, 33 patients (35 knees) remained and were included in this study and followed with a meanfollow-up of 26.6 months. Clinical evaluation was performed using the Western Ontario and McMasterUniversities Arthritis Index (WOMAC score) and the Knee Society rating system that is subdivided intoa knee score (KS) that rates only the knee joint itself and a functional score (FS). Knee Score (KS) andFunctional Score (FS) increased significantly from a mean pre-operative value of 48 and 45, respectively,to a post-operative value at last follow-up of 86 and 82, respectively. Also WOMAC score improvedsignificantly: the mean pre-operative WOMAC score was 45, while the mean post-operative WOMACscore, at last follow-up, was 19. The difference between pre- and post- operative results was significantat statistical analysis. In our opinion, when the adequately prosthesis balancing isn’t possible, because ofprimary or secondary severe varus/valgus deformity or severe soft tissues retraction, an available optionis to perform a total knee arthroplasty with a total stabilizer polyethylene insert. TS prosthesis gives morestability during the most of ROM and, in addition, Triathlon system provides surgeons the possibility tochoose a more constrained implant, than a standard PS one, during surgical procedure saving the bonestock. Our experience with this kind of prosthesis has provided good clinical and radiographic outcomesat a short mid-term follow-up with a low-rate of complications.
Haemophilia is an inherited haemorrhagic disease characterized by the lack of coagulative factors associated nowadays mostly to musculoskeletal complications, particularly severe secondary arthritis in specific joints. Recurrent traumatic or spontaneous joint bleeding, induce severe arthropathy at a young age that can be treated only by joint replacement. Total knee or hip arthroplasty in young subjects may fail earlier due to wear or infections and in the haemophilic population, this means bone loss, pseudo tumours and the need of revision or even limb salvage surgery. Modern modular implants and the use of bone graft enriched by tissue engineering techniques such as a concentration of autologous mesenchymal cells or PRP may be helpful to compensate all bone loss and anatomic alterations due to failures of orthopaedic implants. The authors present their experience with this type of surgery and their biological approach to these challenging cases.
Irisin, a novel myokine produced in response to physical exercise by skeletal muscle, displays anaboliceffect on bone and can improve the bone-loss-induced osteoporosis in hind limb suspended mice. It is wellknown that muscles positively impact the skeleton and in different sports, including soccer, total bodybone mineral density (TB-BMD) is elevated. Therefore, we have investigated the correlation betweenirisin serum levels and total and bone sub-regional BMD in soccer players never studied before. In thisstudy, Caucasian football players of Bari team have been enrolled. Their sera were collected to measureby ELISA kit irisin levels and by dual-energy X-ray absorptiometry (DEXA) analysis measurementsof BMD (g • cm−2) in the whole body and different bone sub-regions (head, arms, legs, ribs, dorsalvertebrae, lumbar vertebrae, pelvis) were performed. The BMC (g) was measured in the whole body.By means of Pearson’s (R) and Cohen’s (d) coefficient we investigated the linear association betweenthe irisin serum levels and BMD. In soccer players, we have found a positive correlation between irisinand TB-BMD as demonstrated by the values of Pearson and Cohen’s (d) coefficient. Furthermore,linear association was detected between irisin and BMD of different bone-site such as right arm, lumbarvertebrae and head. A positive trend was also observed analyzing circulating levels of irisin and bonemineral content as well as total Z-score. In conclusion, we have demonstrated the correlation betweenirisin and total or bone sub-regional BMD in soccer players for the first time, an additional systemiceffect of the “sport-hormone” defined myokine.
An attractive method for osteoarthritis (OA) staging is the measurement of biochemical markersin biological fluids, which could reflect dynamic and quantitative changes in joint remodeling andtherefore disease progression. Proteome analysis has been recognized as one of the most effective toolsto explore biomarkers as it can furnish a wealth of information in both diagnosis and prognosis ofdiseases. We have recently described an innovative tool for peptidome and lipidome profiling of fluidsbased on mesoporous aluminosilicate (MPAS) and Matrix-Assisted Laser Desorption/Ionization timeof-flight Mass Spectrometry (MALDI-TOF MS). The aim of this study was to analyze peptide profilesof human synovial fluid in patients with different grade of OA using MALDI-TOF-MS technique inorder to identify potential markers of disease progression. Twenty-five patients older than 50 years andaffected by primary knee OA diagnosed according to clinical and radiological criteria were enrolled.For each patient a synovial fluid sample was aspirated from the affected knee and analyzed usingMALDI-TOF-MS technique. A statistically significant difference in the normalized area of two peaks(m/z=1865 and m/z=2021) was detected among different stages of OA. The 2 peaks were identified asComplement C3 peptide fragments: C3f and C3f Des-Arg. The expression levels of these two peptides(m/z=1865 and 2021) decreased with the progression of OA degrees severity (ρs=-0.434, p=0.03, andρs=-0.532, p=0.006, respectively). This marker may be a useful tool for assessing the severity of knee OAand it may be a novel target for drug discovery, specifically for the development of disease modifyingOA drugs. However further studies are required to clarify the role of C3f in OA pathogenesis.
A reliable and effective technique in case of limb salvage surgery after resection of extensive bone tumors isrepresented by the implant of modular or custom-made megaprosthesis. Fixation of the residual surroundingsoft tissue on the implant represent a challenge for the surgeon and the use of a polyethylene terephthalate (PET)tube over it, also known as Trevira, is currently a common choice for reattachment with good clinical outcomes.We compared fibroblastic cell culture potential over simple titanium coating vs titanium surrounded by Treviraand evaluated cell viability and replication at 24, 48 and 72 h using MTT cell growth assay and scanning electronmicroscopy to determine if there was any difference in the potential of cell growth associated to the materialused. No significant difference was found at different timings in terms of total cell count for cultures over the twomaterials, but the absolute cell count was slightly higher in the Trevira group in the early time points, reversing thetrend at 72 h of incubation. Ninety-four % of the cells analyzed were vital, regardless of the materials involved inthe experiment, confirming the biocompatibility of titanium and PET. According to the results shown, we are ableto confirm the in vitro safety and efficacy, in terms of newly formed cells extension and adhesion pattern, of usingan attachment tube made from Trevira fibers surrounding an oncological megaprosthesis in order to achieve themost anatomical reinsertion of remaining soft tissue following resection.
Treatment of bone metastases is often palliative, aiming at pain control and stabilization or prevention ofpathological fractures. However, a complete resection with healing purposes can be performed in selectedcases. The aim of our work was to evaluate the survival of megaprostheses used for reconstruction afterbone metastases. Between January 2001 and March 2015, we implanted 169 Megasystem-C® (WaldemarLINK® GmbH & Co. KG, Hamburg, Germany) after bone metastasis resection. Patients, 95 females and74 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 femurin 1 (0.6%). Mostly, breast cancer metastases (30.8%), kidney (17.8%) and lung (14.2%) were treated. Atan average follow-up of 21 (1-150) months, we found a 99.4% overall limb salvage and a 96.1% overallsurvival rate at 1 year, 92.8% at 2 years, and 86.8% at 5 and 10 years. We found 9 (5.3%) mobilizationcases of the proximal femoral implant, 3 needed surgical reduction; 2 (1.2%) cases of aseptic loosening ofthe prosthetic stem; 2 (1.2%) periprotetic infection cases, one requiring a 2-stage revision. Few literaturestudies have evaluated the survival of megaprosthetic implant in the treatment of bone metastases. Ourdata show how in this specific context the rate of complications is significantly lower than expected ingeneral orthopedic orthopedic surgery. The use of modular prostheses is a valid reconstructive strategyafter bone metastasis resection in selected patients. The rate of short-term complications is exceptionallylow; further studies will have to confirm this in the longer term.
In the last years new surgical techniques are developing to improve prosthesis positioning,increasing clinical and functional results and reducing invasiveness. In this scenario patient-specificinstrumentations have been introduced in order to enhance surgical accuracy and ease of implantation.The purpose of this study was to assess the compliance of the pre-operative planning data with boneresections measured intraoperatively and to evaluate prosthesis positioning in patients undergoingtotal knee arthroplasty (TKA) using an MRI-based pin-guides instrumentation. Thirty consecutivepatients (20 women and 10 men) undergoing 30 total knee replacements (20 right- and 10 left-sidedknees) were included in this study. The same cemented cruciate ligament sacrificing prosthesis (NexGenLPS, Zimmer, Warsaw, Indiana, USA) was implanted in all patients by a single surgeon using Patient-Specific Instruments (PSI, Zimmer, Warsaw, Indiana, USA). Femoral and tibial bone resections weremeasured using a manual caliper intra-operatively and compared with the corresponding pre-operativevalues. Each patient underwent A CT examination following surgery in order to investigate individualcomponent positioning. None of the cases was converted from PSI technique to conventional TKA andadequate femoral and tibial bone cuts were performed without the need for intraoperative adjustments.Two outliers were detected among the intra-operative bone cuts measurements. In all patients the size offemoral and tibial prosthetic components, hypothesized at preoperative planning, was confirmed intraoperatively.Two outliers were detected among post-operative CT measurements as for componentspositioning. PSI system can assist in obtaining good component positioning with reduction of outliers.Despite the small number of patients, our data demonstrate the validity of this patient-specific pin-guidessystem in TKA and may support repeatable improvements in surgical accuracy. Level of evidence: IV.
The aim of this study was to evaluate the effect of an in vitro mechanical stimulation by the use of a bioreactor on an engineered tendon for 7 and 14 days and to analyze the effect of the use of different cell sources: tenocytes, dermal fibroblasts or Adipose-Derived Stem Cells (ASCs), isolated from pig tissues. Histology showed a re-organization of the neo-tissue derived from the three cell populations along the direction of the stimulus. At T7, cells morphology was preserved while an increased cellular suffering at T14 was observed for all cell populations. Tenocytes exhibited higher survival than other cells. A stable immunopositivity for collagen type 1 or 3 at both time points was also observed. In conclusion, dermal fibroblasts and ASCs represent an interesting alternative and in vitro culture with mechanical stimuli may enhance the maturation of a tendon-like tissue.
This study evaluated a tendon substitute model. Tenocytes were isolated from pig Achilles tendon, seeded onto scaffolds (Opocrin 2%, Typeone 3% and Symatese 2%) and studied by histology, immunofluorescence for collagen type 1 and 3 and biochemical analysis to assess cellularity. The permeability of these compounds was evaluated in the presence or absence of fibrin glue. Opocrin 2% was the best choice for cellular distribution within the scaffolds, which were then cultured for T0, T4, T7 and T10 days. Fibrin glue has been strongly supportive for the survival of cells with a significant increase in DNA content at T10 (P>0.05). Moreover, the synthetic activity of fibrin-free scaffolds was always negative. Lastly, a progressive increase in collagen 1 and 3 with fibrin-glue was observed. However, static culture is not sufficient to support long-term cellular activities and at T10 there is still a lack of organized matrix similar to the native tissue.
Main surgical approaches to the hip have been modified during last decades, in an effort to reduceinvasiveness of the surgical procedure and allow a faster rehabilitation. Direct anterior approach is theonly approach, which does not require muscle detachment, thus theoretically leading to reduced postoperativepain and allows earlier recovery. The aim of this study was to report a comparison betweenpatients operated with direct anterior approach and postero-lateral approach in terms of immediatepost-operative and in-hospital records. Pain, operative time, intra- and post-operative complications,blood loss, hospitalization, motor component of the Functional Independence Measure (M-FIM),timed up and go (TUG) test were measured between the two groups and compared. Direct anteriorapproach showed better results in M-FIM, TUG, hospitalization and blood loss, without any significantdifference for intra- and post-operative complications between the 2 groups. This study shows thatearly post-operative recovery is influenced by the chosen approach. Direct anterior approach showedbetter outcomes when compared to postero-lateral approach, limited to hospitalization, blood loss, andfunctional scores. Further comparisons are needed to evaluate direct anterior approach to maintainadvantages over postero-lateral approach on longer follow-up period.
Direct anterior approach for THA has gained popularity over the last years. However, concerns havebeen raised regarding the cosmetic, related to the incision that does not respect the Langer’s skin tensionline and may produce hypertrophic scars. The aim of this study was to analyze the preliminary results in22 young female patients undergoing THA through a minimally invasive direct anterior approach usinga modified oblique bikini incision. Clinical evaluations showed an improvement of WOMAC, UCLA andHarris Hip Score at 5-month follow-up. The technique ensured proper implant positioning and showedadvantages in terms of complications, transfusion rates, hospital length of stay and functional recovery.From the aesthetic point of view, the expected cosmetic results were obtained. Minimally invasive directanterior approach using a modified oblique bikini incision represent a viable option for THA, combiningboth the advantages of a minimal invasive procedure with a better aesthetic appearance.
Direct vertebral rotation (DVR) is widely used to correct the axial deformity in adolescent idiopathic scoliosis (AIS). Indirect rotation techniques may help DVR in order to improve outcome. Vertebral translation technique combined with the use of two differently shaped rods resulted effective in reducing the rib hump deformity. The aim of this study is to describe the technique and evaluate the efficacy of combined DVR and vertebral translation technique on axial deformity correction. Mean follow-up was 2.7 years. Cobb angle, kyphosis angle, apical vertebrae axial rotation angle, SRS-22 questionnaire of 30 AIS patients treated with combined DVR and differently shaped dual rods translation technique were collected and compared preoperatively and postoperatively. At the last follow-up no screw pull-out, nonunion or loss of correction were recorded. The combination of DVR and differently shaped dual rods translation technique in AIS can provide good three-dimensional correction and improvement of patient’s quality of life.
Gamma-glutamyltransferase (GGT) has been recently identified as a bone-resorbing factor. The aimof 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 establishedquantitatively by two micro-CT derived microarchitectural parameters: the BV/TV (mineralised bonevolume/total volume), and the SMI (structure model index) that describes the rod-like (low resistant) orplate-like (high-resistant) shape of bone trabeculae. We enrolled 93 patients hospitalised for elective totalhip replacement (group Arthrosis, n=46) or for proximal femoral fracture (group Fracture, n=47). Patientswithin the first quartile of BV/TV (Q1, osteoporotic patients, n=6) showed higher levels of b-GGT fraction[median (min-max): 3.37 (1.42–6.81)] compared to patients with normal bone density (fourth quartileQ4, n=10; 1.40 (0.83–4.36); p=0.0393]. Also, according to SMI, b-GGT value was higher in the subgroupwith bone fragility [Q1, n=8: 1.36 (0.43–4.36); Q4, n=8: 5.10 (1.4 –7.60); p=0.0117]. In conclusion, patientscharacterised by fragile bone structure showed specifically higher levels of plasma b-GGT activity thussuggesting fractional GGT analysis as a possible biomarker in the diagnosis of osteoporosis.
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.
Minced cartilage fragments are a viable cell source for one stage cartilage repair. However, the joint surfaceis a low oxygen tension microenvironment and little evidence is present in literature regarding the behaviourof cartilage fragments in this peculiar condition. The aim of the study is i) to verify if low oxygen tension couldnegatively influence chondrocyte outgrowth from cartilage fragments into a Hyaluronic-Acid(HA)/fibrin scaffoldand ii) to evaluate its effects on the behaviour of migrating chondrocyte, compared to normoxic condition. A slightdecrease in chondrocyte migration and proliferation was observed in low oxygen tension cultures. Conversely, anincrease in the expression of SOX9, β-catenin, HIFs, collagen-I and II (p<0.05) in migrating chondrocytes fromlow oxygen tension cultures was present. Thus, a long term- exposure at low oxygen tension seems to improve thechondrocytic phenotype expression of cell outgrowing from cartilage fragments onto a HA/fibrin scaffold.
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 modeland the mechanic model. Our goal is to evaluate thromboelastographic changes in patients undergoingsurgery for femoral neck fractures. We recruited 32 patients with a femoral neck fracture. The averageage was 81.91 years (range 62-95). The patients were divided in two different groups: cemented hiparthroplasty (CC, 13 patients) and other surgical non-cemented techniques (SC, non-cemented hiparthroplasty, osteosynthesis). The coagulation was evaluated by TEG in the early pre-operatory (timeA) and post-operatory (time B), both on native blood and on blood added with Heparinase. We usedthe t-test to compare the differences between the two groups. The coagulation index CI was modified onhypercoagulability 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 TEGtoward hypercoagulability, this is similar both in cemented and non-cemented surgical interventions forfemoral neck fractures in elderly patients. An altered coagulation does not appear to be the cause or afactor in determining the BCIS.
In the last few years, different tissue engineering strategies have been developed for the repair ofosteochondral lesions. When the osteochondral scaffold is implanted on the femoral condyle, themeniscus might be affected by the implant and might undergo a progressive degeneration. The aim ofour study is to analyze the morphological changes of the meniscus following an osteochondral lesion andthe implant of a biphasic scaffold. A critical osteochondral defect was generated in the medial femoralcondyle of mature sheep. Three defects were left untreated, the remaining lesions were divided intothree groups and treated with a biphasic substituted formed by collagen type I and Wollastonite orWollastonite/Hydroxyapatite. Animals were sacrificed after 6 months and menisci were isolated andanalyzed by arthro-CT, macroscopic evaluation and histology. The results demonstrated that theosteochondral lesion negatively affects meniscus morphology and that the osteochondral substitute onlypartially mitigates the meniscus degeneration.
Non-union (or pseudoarthrosis) is defined as a fracture that fails to consolidate after 6 monthsfrom the trauma. Current conservative treatments consist of biological (i.e. with calcium, VitaminD) and mechanical stimulation. Moreover, surgical approaches include the use of endomidollar nailosteosynthesis, compression plates that are often associated with bone grafts. External fixation is a validsurgical alternative especially in case of septic non-unions. Indeed, compression-distraction osteosynthesisresults in a significant improvement in bone vascularisation and exerts a powerful osteoinductivestimulus on the non-union site. In this review, we will describe a cohort of patients affected by low-gradeseptic non-unions and treated with external fixation.
Chronic ulcers of the lower limbs represent a significant social and economic burden. Diabetes isa strong risk factor for development of chronic lesions. Adult stem cells and growth factors derivedfrom the adipose tissue are among the most promising therapeutic strategies for hard to heal wounds.Fat grafts have been used for several decades to treat soft tissue deformities, but despite its excellentcharacteristics, the outcome was unpredictable, due to partial necrosis and resorption of the graft. Stemcells’ enrichment of these grafts or their injection into the edges of the ulcers have shown encouragingresults in various experimental settings. In this pilot study, we compared the standard of care toautologous lipotransfer and stromal vascular fraction (SVF) enriched lipoinjection in 30 patients withdiabetic foot ulcers, showing clear superiority of SVF enriched lipoinjection in terms of percentage ofreduction of ulcers size and healing time.
Chronic osteoarticular infections such as osteomyelitis or periprosthetic joint infection (PJI) have become a growing problem over the years. The “gold standard” in local antibiotic administration is still the antibiotic-loaded acrylic bone cement (ALABC) which is used in both prophylaxis, because it has been shown it can reduce the risk of infection and used in therapy during a “two-stage surgery” in PJI or in chronic osteomyelitis. We performed morphological analysis of three different formulations of antibiotic-loaded cement (ALABC) using techniques of light microscopy, scanning electron microscopy (SEM) and 3D immunofluorescence, in order to explain how the morphological aspects of cement could influence and modulate antibiotic elution.
Only 5-10% of partial tears of the anterior cruciate ligament (ACL) are symptomatic, especially in high demand individuals or in patients practicing sports requiring rotational motions.. A certain preoperative diagnosis of this condition is challenging and often needs the combination of clinical examination, magnetic resonance imaging (MRI) and knee-laxity tool measurements. However, the arthroscopic examination of the torn ACL bundle is the most important factor in decision-making. Evidence in various studies have shown that the preservation of the ACL remnant and its surgical augmentation can bring important advantages in terms of vascularity and proprioception, resulting in better outcomes. The purpose of our paper was to describe the surgical technique of arthroscopic posterolateral (PL) bundle reconstruction with the preservation of the anteromedial (AM) bundle for ACL partial tears. Moreover, we reported the current knowledge about rationale, diagnosis and treatment of partial tears of ACL.
Minimally Invasive Spine Surgery (MISS) procedures for the treatment of spinal pathologies haveexperienced exponential growth due to improved techniques and decreased trauma to the patient. SeveralMISS procedures that require the use of a trans-pedicular cannula as a guiding tool for pedicle screwplacement, delivery of biomaterials to the vertebral body or injection of biologics to the disc space havebeen described. Although these are clear advantages of MISS, the limited dissection and exposure mayreduce the accuracy and stability of operation and make spine surgeons rely heavily on intraoperativefluoroscopy, raising concerns over the level of radiation exposure. Robot-assisted minimal invasive surgeryhas aroused more attention for its high precision and stability, minimizing risks of damage to neurovascularstructures and diminishing harmful exposure to ionizing radiation. The aim of this paper is to describe andcharacterize a new surgical positioning system for for robotic assisted MISS. The system is conceived to beintegrated in a surgical platform capable of supporting the surgeon in a new procedure to treat degenerativeintervertebral disc disease. For this purpose, it is necessary to orientate a cannula in order to guide thebone drill along a planned route, to access the intervertebral disc through the pedicle and endplate. Inparticular, we describe a mechanism that percutaneously guides a cannula towards the intervertebral discbased on the acquisition of few fluoroscopic images. The design of the positioning system, with its featuresand constrains imposed by the presence of instrumentation and medical staff in the operating room, as wellas the software for trajectory planning during surgery, are here described.
Vertebral fusion is performed in order to stabilize the spine in the presence of degenerative, traumatic or oncological pathologies that alter its stability. The autologous bone, harvested from the patient’s iliac crest or from the lamina during surgery, is still considered the “gold standard” for spine fusion due to its osteogenic, osteoinductive and osteoconductive properties. However, several biological and synthetic bone substitutes have been introduced as alternatives for regenerating bone tissue. We have studied in particular the use of ceramic biomaterials prepared from hydroxypatite (HA), starting from in vitro analysis, through an in vivo study on ovine animal model and a post-market surveillance analysis, to finally design and perform a clinical study, which is ongoing in our Department. In the first step, HA-derived biomaterials were tested in vitro in the presence of bone marrow-derived human mesenchymal stem cells (hMSCs) and evaluated for their ability to activate precursor cells. In the second step, the biomimetic bone graft substitute SintLife® putty (MgHA) was evaluated in vivo. A posterolateral fusion procedure was applied on 18 sheep, where a fusion level was treated with MgHA, while the other level was treated with autologous bone. Microtomography and histological/histomorphometric analysis were performed six months of after surgery. In the third step, we reported the results of a post-market surveillance study conducted on 4 independent cohorts of patients (total 115 patients), in which HA-derived biomaterials were used as bone graft substitutes or extenders. Finally, a clinical study has been designed and approved by the Ethics Committee of our Institute and is currently ongoing. This study aims to evaluate the efficacy of the ceramic biomaterial SintLife® putty for bone replacement in patients treated by posterolateral fusion for degenerative spine disorders. HA biomaterials were effective in promoting the in vitro growth of hMSCs and their osteogenic differentiation. In the animal model, SintLife® putty has been effective in generating neo-formed bone tissue with morphological and structural features similar to those of the pre-existing bone. The post-market surveillance analysis has not reported any intra-operative nor early or late post-operative adverse events. Seven patients are currently recruited for the clinical trial designed to evaluate Sintlife efficacy for spine fusion (FU range: 1-7 months). No adverse events have been recorded. The first CT analysis performed at 6 months FU showed a good spine fusion. The study is ongoing. Our results, obtained from in vitro, preclinical and clinical studies, suggest that biomaterials derived from hydroxyapatite could be a valid alternative to autologous bone graft for vertebral fusion. This would potentially avoid or reduce the need of autologous bone harvesting and therefore, the risk of drawback-related side effects.
Targeted muscle reinnervation (TMR) is a novel surgical technique developed to improve the controlof myoelectric upper limb prostheses. Nerves transected by the amputation, which retain their originalmotor pathways even after being severed, are redirected to residual denervated muscles that serve astarget for consequent reinnervation. Once the process is complete, reinnervated muscles will contractupon voluntary activation of transferred nerves while attempting to move missing regions of theamputated limb, generating EMG signals that can be recorded and used to control a prosthetic device.This allows creating new control sites that can overcome major drawbacks of conventional myoelectricprostheses by offering a more natural and intuitive control of prosthetic arms. TMR has been widelyperformed in individuals who underwent shoulder disarticulation amputation and transhumeralamputation since proximal amputations do not leave enough functional muscles exploitable to controlindependent degree of freedoms of multi-articulated prostheses. TMR application is currently underinvestigation in patients suffering further distal amputations, as well as for treating and preventingpainful post-amputation neuromas. The purpose of this paper is to describe the physiologic basis and thesurgical technique of TMR, reporting current knowledge on the clinical results.