Andrea Poggetti

Magnetic Nanoparticles for Efficient Delivery of Growth Factors: Stimulation of Peripheral Nerve Regeneration

The only clinically approved alternative to autografts for treating large peripheral nerve injuries is the use of synthetic nerve guidance conduits (NGCs), which provide physical guidance to the regenerating stump and limit scar tissue infiltration at the injury site. Several lines of evidence suggest that a potential future strategy is to combine NGCs with cellular or molecular therapies to deliver growth factors that sustain the regeneration process. However, growth factors are expensive and have a very short half-life; thus, the combination approach has not been successful. In the present paper, we proposed the immobilization of growth factors (GFs) on magnetic nanoparticles (MNPs) for the time- and space-controlled release of GFs inside the NGC. We tested the particles in a rat model of a peripheral nerve lesion. Our results revealed that the injection of a cocktail of MNPs functionalized with nerve growth factor (NGF) and with vascular endothelial growth factor (VEGF) strongly accelerate the regeneration process and the recovery of motor function compared to that obtained using the free factors. Additionally, we found that injecting MNPs in the NGC is safe and does not impair the regeneration process, and the MNPs remain in the conduit for weeks.

Nanoparticles for Tendon Healing and Regeneration: Literature Review

Tendon injuries are commonly met in the emergency department. Unfortunately, tendon tissue has limited regeneration potential and usually the consequent formation of scar tissue causes inferior mechanical properties. Nanoparticles could be used in different way to improve tendon healing and regeneration, ranging from scaffolds manufacturing (increasing the strength and endurance or anti-adhesions, anti-microbial, and anti-inflammatory properties) to gene therapy. This paper aims to summarize the most relevant studies showing the potential application of nanoparticles for tendon tissue regeneration.

Human mesenchymal stromal cell-enhanced osteogenic differentiation by contact interaction with polyethylene terephthalate nanogratings

Among the very large number of polymeric materials that have been proposed in the field of orthopedics, polyethylene terephthalate (PET) is one of the most attractive thanks to its flexibility, thermal resistance, mechanical strength and durability. Several studies have been proposed that interface nano- or micro-structured surfaces with mesenchymal stromal cells (MSCs), demonstrating the potential of this technology for promoting osteogenesis. All these studies were carried out on biomaterials other than PET, which remains almost uninvestigated in terms of cell shaping, alignment and differentiation. Here, we study the effect of PET 350-depth nanogratings (NGs) with a ridge and lateral groove size of 500 nm (T1) or 1 μm (T2), on bone marrow-derived human MSC (hMSC) differentiation in relation to the osteogenic fate. We demonstrate that these substrates, especially T2, can promote the osteogenic phenotype more efficiently than standard flat surfaces and that this effect is more marked if cells are cultured in osteogenic medium than in basal medium. Finally, we show that the shape and disposition of calcium hydroxyapatite granules on the different substrates was influenced by the substrate symmetry, being more elongated and spatially organized on NGs than on flat surfaces.

Treatment of Scaphoid Waist Nonunion Using Olecranon Bone Graft and Stryker Asnis Micro Cannulated Screw: A Retrospective Study-80 Case Studies and 6 Years of Follow-Up.

Background Screw fixation and bone grafting are the gold standard for scaphoid waist nonunion without avascular necrosis. Question/Purpose Assesses the scaphoid waist nonunion healing rate with use of an uncommon cancellous bone graft (olecranon) and an unusual fixation system (Asnis Micro Cannulated Screw System; Stryker Inc., Kalamazoo, MI, USA). Material and Methods A series of 102 consecutive patients were treated for scaphoid waist nonunion (without deformity). Of these, 80 patients subjected to clinical (Modified Mayo Wrist Score (MMWS), Jamar hydraulic dynamometer) and radiographic examination before and after surgery were evaluated. Ipsilateral olecranon cancellous bone graft and the ASNIS Micro 3.0-mm diameter screw, were used. The average follow up was 6 years (min 3; max 10). Results Radiographic consolidation was achieved in 90% of patients; dorsal intercalated segment instability (DISI) deformities were corrected in 71.4% of cases. Ninety percent improved the range of motion of the wrist and grip strength. All patients showed a significant reduction of peak force in the operated hand. In 6.25% we observed clinical and radiographic screw head-trapezium impingement. Twenty-six patients developed a degenerative wrist sign. The MMWS yielded 68 optimal, 8 good, and 4 bad results. Conclusions To treat scaphoid waist nonunions without misalignment, low-profile headed screw and olecranon bone graft allowed a high consolidation rate with positive results to long-term follow-up. The Asnis Micro 3.0 mm diameter screw may be a suitable option for treating scaphoid waist nonunion. Level of Evidence IV.

Progressive Brachial Plexus Palsy after Osteosynthesis of an Inveterate Clavicular Fracture

Introduction: The thoracic outlet syndrome (TOS) is a rare complication of clavicular fracture, occurring in 0.5-9% of cases. In the literature from 1965 – 2010, 425 cases of TOS complicating a claviclular fracture were described. However, only 5 were observed after a surgical procedure of reduction and fixation. The causes of this complication were due to the presence of an exuberant callus, to technical surgery errors or to vascular lesions. In this paper we describe a case of brachial plexus plasy after osteosynthesis of clavicle fracture Case Report: A 48 year old female, presented to us with inveterate middle third clavicle fracture of 2 months duration. She was an alcoholic, smoker with an history of opiate abuse and was HCV positive. At two month the fracture was displaced with no signs of union and open rigid fixation with plate was done. The immediate postoperative patient had signs of neurologic injury. Five days after surgery showed paralysis of the ulnar nerve, at 10 days paralysis of the median nerve, radial and ulnar paresthesias in the territory of the C5-C6-C7-C8 roots. She was treated with rest, steroids and neurotrophic drugs. One month after surgery the patient had signs of complete denervation around the brachial plexus. Implant removal was done and in a month ulnar and median nerve functions recovered. At three months post implant removal the neurological picture returned to normal. Conclusion: We can say that TOS can be seen as arising secondary to an “iatrogenic compartment syndrome” justified by the particular anatomy of the space cost joint. The appropriateness of the intervention for removal of fixation devices is demonstrated by the fact that the patient has returned to her daily activities in the absence of symptoms and good functional recovery in about three months, despite fracture nonunion.

Percutaneous Intramedullary Headless Screw Fixation and Wide-Awake Anesthesia to Treat Metacarpal Fractures: Early Results in 25 Patients

Metacarpal fractures constitute 7.8% of the upper extremity fractures. The common treatments remain nonsurgical procedure, but high-demanding patients or unstable fractures require fixation with Kirschner wire (K-wires), plate, and screws. However, these approaches may cause scarring and adhesion with poor functional results. From 2014 to 2015, the authors used an intramedullary headless screw to treat 25 patients (24 men, 1 woman) with metacarpal bones fractures (20 V, 3 IV, 1 III, and 1 II). The fractures patterns were 23 fractures of distal third of metacarpal bone (16 oblique, 5 comminute configurations, and 2 transverse), 1 fracture of the base of the II metacarpal bone. One case presented a multiple metacarpal and phalangeal facture associated. The authors used wide-awake anesthesia (bupivacaine-epinephrine 1:100,000) and intramedullary titanium headless screw fixation percutaneously inserted (CCS Medartis and HCS Synthes 3 mm of diameter). No open reduction was needed. Early active mobilization started with a buddy strapping soon after surgery (0-3 days). The authors followed all patients until satisfactory function was achieved (4-6 weeks) and recorded the time till return to work. All fracture healed with less than 5 degrees of rotational or axial deformities. All patients return to work within 2.38 weeks after surgery (0.5-6 weeks). No cases of complex regional pain syndrome (CRPS), tendon lesions, nerve injuries, infection, hardware protruding, or mobilization were reported. Intramedullary screw fixation with wide-awake anesthesia for transverse, oblique, and select comminuted fractures treatment metacarpal fractures represent a reliable option to early active mobilization recovery and a quick return to the work and ordinary activities.

Traumatic anterior dislocation of a prosthetic knee, from trauma to delayed onset of vascular injury

Anterior dislocation of a prosthetic knee is a rare event. Only few episodes have been described in the past and have never been linked with neurovascular injury. This could lead orthopaedic surgeons to focus on the implant instability factors and underrate other complications. The authors report a case of a patient who experienced popliteal artery dissection 80 hours after traumatic anterior knee dislocation of a previously well-functioning total knee arthroplasty. Given that there is a lack of clinical cases that have established guidelines for management of this problem, the authors have focused on the importance of performing computed tomography angiography in the management of an anterior traumatic knee dislocation of a prosthetic knee.

Surgical Treatment for a Relapsing Malleolar Bursitis in a Professional Figure Skating: Case Report

The increase of popularity in sports as Roller Skating, Figure Skating and Ice Hockey has simultaneously increased the number of skating-related injuries. Lesions of chronic dermatological nature and muscle and tendon lesions have high number of case reports. Ankle and foot are peculiarly involved and this condition suggests the correlation with the use of the skating boot, which with its high-cut and hard-fit changes the joint biomechanics and function and, as a result, the intergumentary system is continuously damaged by the compression and rubbing on the foot. The frequent onset of non-septic chronic relapsing bursitis at the level of the malleolar region is common in all sports requiring the use of skating boots. The conservative treatment is usually compromised by the repetition of the traumatic event due to the use of the skating boot. The case report of a 19 year old professional figure skater affected by non-septic relapsing malleolar bursitis at the level of the malleolar region is presented.

Atraumatic Bilateral Neglected Anterior Shoulder Dislocation: Case Report of a Jehovah's Witness 28-Year-Old Male Affected by Iron-Deficiency Anemia and Treated with Bilateral Latarjet Procedure.

Introduction: Neglected bilateral anterior shoulder dislocation is a very rare condition, often related to seizures or major trauma. Open reduction is recommended whenever Hill-Sachs lesion is >25% of the joint and the dislocation is elder than 3 weeks. Case Report: We describe a case report of a 28-year-old man left handed Jehovah’s Witness laborer assessed 12 weeks after bilateral anterior shoulder dislocation. The patient was evaluated with clinical examination, and it was observed an asymptomatic intrarotation of both shoulders with a mild left circumflex nerve deficit. He was able to perform flexion and abduction of both arms up to 60° and 10° of extrarotation. Pre-operative constant scores were 49 in left and 55 in right shoulder, pre-operative disabilities of the arm, shoulder, and hand (DASH) scores were 57 in left and 53 in right shoulder, and visual analogue scales (VAS) was 2. Radiological examination were bilateral anteroposterior shoulder X-rays and computer tomography scan. The surgeon treated both shoulder (not simultaneously) by open reduction and Bristow-Latarjet coracoids transfer procedure. A 1 year after operations, left flexion was 180° while right was 160, bilateral abduction was 180. He was able to return to his pre-injury activities, the constant score was 89 left and 83 right, DASH score was 17 left and 13 right and VAS was 0. Conclusion: Atraumatic bilateral neglected anterior shoulder dislocation can be treated with open Bristow-Latarjet procedure to provide a stable glenohumeral joint in laborer patient and permit a return to the pre-injury activities, to create a greater extension of the glenoid arc and to avoid future dislocation.