4D printing of biodegradable elastomers with tailorable thermal response at physiological temperature.

4D printing has a great potential for the manufacturing of soft robotics and medical devices. The alliance of digital light processing (DLP) 3D printing and novel shape-memory photopolymers allows for the fabrication of smart 4D-printed medical devices in high resolution and with tailorable functionalities. However, most of the reported 4D-printed materials are nondegradable, which limits their clinical applications. On the other hand, 4D printing of biodegradable shape-memory elastomers is highly challenging, especially when transition points close to physiological temperature and shape fixation under ambient conditions are required. Here, we report the 4D printing of biodegradable shape-memory elastomers with tailorable transition points covering physiological temperature, by using poly(D,L-lactide-co-trimethylene carbonate) methacrylates at various monomer feed ratios. After the programming step, the high-resolution DLP printed stents preserved their folded shape at room temperature, and showed efficient shape recovery at 37 °C. The materials were cytocompatible and readily degradable under physiological conditions. Furthermore, drug-loaded devices with tuneable release kinetics were realized by DLP-printing with resins containing polymers and levofloxacin or nintedanib. This study offers a new perspective for the development of next-generation 4D-printed medical devices.

Legg-Calvé-Perthes disease.

Current knowledge of the causes and risk factors of Legg-Calvé-Perthesdisease (LCPD) does not allow effective preventive strategies. The outcome in adulthood is usually good. Hip osteoarthritis rarely develops before 50 years of age. The risk of osteoarthrosis depends chiefly on the final degree of joint incongruence. Age at onset and the lateral pillar classification are the two main outcome predictors and serve to guide the surgical indications based on the studies by Herring's group. Non-operative treatment is not effective. In contrast, femoral varus osteotomy and Salter's innominate osteotomy provide good outcomes. In severe forms, however, combining these two techniques or performing a triple pelvic osteotomy seem preferable. Surgery is now performed considerably less often than in the past, as it is effective only in patients with lateral pillar group B or B/C disease with onset after eight years of age. In other situations, therapeutic abstention is recommended.

Five-year outcomes of the First Distal Uninstrumented Vertebra after posterior fusion for Adolescent Idiopathic Scoliosis Lenke 1 or 2.

BACKGROUND: Tilt of the First Distal Uninstrumented Vertebra (FDUV) reflects changes in the main curve and compensatory lumbar curve after posterior fusion to treat thoracic Adolescent Idiopathic Scoliosis (AIS). HYPOTHESIS: FDUV tilt 5 years or more post-fusion depends chiefly on reduction of the main curve and on other factors such as selection of the last instrumented vertebra. MATERIAL AND METHOD: A multicenter retrospective cohort of 182 patients with Lenke 1 or 2 AIS treated with posterior instrumentation and followed up for a mean of 8 years and a minimum of 5 years was studied. The patients were divided into two groups based on whether tilt of the upper endplate of the FDUV was ≤5° or >5°at last follow-up. Variables associated with tilt were identified by multiple logistic regression. RESULTS: Six variables were significantly associated with FDUVtilt: percentage of correction at last follow-up, correction loss, lumbar modifier B, number of instrumented vertebrae, inclusion within the instrumentation of the distal neutral vertebra, and inclusion within the instrumentation of the lowest vertebra intersected by the central sacral vertical line. DISCUSSION AND CONCLUSION: The main variables associated with FDUVtilt ≤5° were a final correction percentage ≥60% and absence of correction loss between the postoperative period and last follow-up. Given the stable reduction provided by contemporary instrumentations, we recommend selective thoracic fusion of Lenke 1 or 2 AIS with lumbar modifiers A, B, and C. The lowest instrumented vertebra should be either the neutral vertebra or the vertebra intersected by the central sacral vertical line if it is distal to the neutral vertebra. LEVEL OF EVIDENCE IV: Retrospective multicenter study.

[Slipped capital femoral epiphysis]. / Épiphysiolyse fémorale supérieure.

Slipped capital femoral epiphysis (SFCE) is a disorder of the hip, characterized by a displacement of the capital femoral epiphysis from the metaphysic through the femoral growth plate. The epiphysis slips posteriorly and inferiorly. SCFE occurs during puberty and metabolic and epidemiologic risk factors, such as obesity are frequently found. Most chronic slips are diagnosed late. Sagittal hip X-rays show epiphysis slip. In case of untreated SCFE, a slip progression arises with an acute slip risk. Treatment is indicated to prevent slip worsening. The clinical and radiological classification is useful to guide treatment and it is predictive of the prognosis. In situ fixation of stable and moderately displaced SCFE with cannulated screws gives excellent results. Major complications are chondrolysis and osteonecrosis and the major sequelae are femoroacetabular impingement and early arthritis.

Releasable and traceless PEGylation of arginine-rich antimicrobial peptides.

Arginine-rich antimicrobial peptides (AMPs) are emerging therapeutics of interest. However, their applicability is limited by their short circulation half-life, caused in part by their small size and digestion by blood proteases. This study reports a strategy to temporarily mask arginine residues within AMPs with methoxy poly(ethylene glycol). Based on the reagent used, release of AMPs occurred in hours to days in a completely traceless fashion. In vitro, conjugates were insensitive to serum proteases, and released native AMP with full in vitro bioactivity. This strategy is thus highly relevant and should be adaptable to the entire family of arginine-rich AMPs. It may potentially be used to improve AMP-therapies by providing a more steady concentration of AMP in the blood after a single injection, avoiding toxic effects at high AMP doses, and reducing the number of doses required over the treatment duration.

Surgical treatment using The Unit Rod in children with neuromuscular scoliosis.

The article represents a retrospective clinical and radiological study. Objective. To assess the safety and the stability in time of the Unit Rod instrumentation in the treatment of severe neuromuscular scoliosis in children and adolescents. Summary. The treatment of patients with neuromuscular scoliosis always represents a challenge. The patients are debilitated and usual interventions are very long with great loss of blood. Serious complications can compromise the result of the surgery. The technique we used (the Unit Rod) is worldwide recognized, is simple, and gives excellent stability with a low rate of complications. Methods. We conducted a clinical and radiological retrospective study with a follow-up of at least 4 years in 58 patients with serious neuromuscular conditions, most of them being non-walkers. They were surgically treated by using mostly the Unit Rod technique, in the department of Paediatric Orthopaedics of the Rouen University Hospital, France, between 2000 and 2008. The back fusion was generally from T2 to pelvis. We used the Galveston technique for the patients who needed a pelvic fixation. Results. The mean Cobb angle correction was of 67% immediately after surgery; the correction of the curve decreased in time only in 4% of the cases. Pelvic obliquity was also very well corrected: 73% immediately and 70% at the last radiological follow-up. The mean operative time was of 175 minutes compared to 269 minutes for screws and hooks instrumentation. The most common complication for our technique was the radiolucent halo that appeared around the pelvic inserts. There was no significant degradation in time of the correction obtained. Conclusions. The use of this technique is safe, gives excellent results, achieving significant improvements in the postoperative functional status of the patients. The intra- and postoperative complications were minor. The advantage of using this method is the low cost of the material and technical simplicity, the corrective results being the same as the ones obtained with other techniques.

Cervical myelopathy involving os odontoideum and retro-odontoid cyst treated with Harms C1-C2 arthrodesis.

An episode of acute decompensation of cervical myelopathy occurred after an injury without fracture of an os odontoideum associated with a compressive retro-odontoid cyst. The 51-year-old female patient presented Fränkel C, Nurick grade 4 neurological status and pyramid syndrome. The initial MRI demonstrated an intramedullary T2 hyperintense signal in the context of spinal cord narrowing. The retro-odontoid cyst demonstrates atlantoaxial instability related to the os odontoideum. Harms C1-C2 arthrodesis without laminectomy was performed and the cyst disappeared completely. Spinal cord decompression was thus obtained on the MRI taken 3 months later. Neurological recovery was complete and continued at 1 year.

[Are C2 pedicles always screwable? Calibration and planning with a pedicle-lamina angle]. / Les pédicules de C2 sont-ils toujours vissables ? Calibration et planification selon l'angle pédiculo-lamaire.

INTRODUCTION: Posterior cervical arthrodesis is associated with osteosynthesis. C2 pedicular screwing affords a good bone anchoring but involves neurological and vascular risks. PURPOSE: To determine C2 pedicular screwing feasibility from a large cohort of cervical CT scans. To describe the visible anatomical parameters during a surgical procedure in order to plan and secure it. MATERIALS AND METHODS: Retrospective consecutive series of 100 cervical CT scans was analyzed. Cases with upper cervical fracture were excluded. C2 surgical anatomy was assessed according to maximum length, minimum width and minimum height. Angular parameters were pedicle-transverse angle and sagittal angle. Original pedicle-lamina angle was used as a visible mark during the procedure independent of the patient's position. Pedicular screwing feasibility was evaluated. It was arbitrarily defined by a lower minimum height less than 4mm. RESULTS: Two hundred C2 pedicles were analyzed with 7.5% that were not screwable. Their mean length was 26.2mm, with a mean width of 5.2mm and a mean height of 9.2mm. Mean pedicle-transverse angle was 36.2°, mean sagittal angle was 25.8° and mean pedicle-lamina angle was 81.3°. CONCLUSION: C2 pedicle screwing feasibility is inconstant due to anatomical variability. In fact, 13% of patients have at least one non-screwable pedicle. Preoperative planning is essential to achieve this procedure. A pedicle-lamina angle can be used which remains independent from the patient's position.

Evolution of adolescent idiopathic scoliosis: results of a multicenter study at 20 years' follow-up.

INTRODUCTION: To date there is no consensus on therapeutic indications in adolescent idiopathic scoliosis (AIS) with curvature between 30° and 60° at the end of growth. OBJECTIVE: The objective of this study was to assess outcome in patients with moderate AIS. MATERIAL AND METHODS: A multicenter retrospective study was conducted. Inclusion criteria were: Cobb angle, 30-60° at end of growth; and follow-up > 20 years. The data collected were angular values in adolescence and at last follow-up, and quality of life scores at follow-up. RESULTS: A total of 258 patients were enrolled: 100 operated on in adolescence, 116 never operated on, and 42 operated on in adulthood. Mean follow-up was 27.8 years. Cobb angle progression significantly differed between the 3 groups: 3.2° versus 8.8° versus 23.6°, respectively; P < 0.001. In lumbar scoliosis, the risk of progression to ≥ 20° was significantly higher for initial Cobb angle > 35° (OR=4.278, P=0.002). There were no significant differences in quality of life scores. DISCUSSION: Patients operated on in adolescence showed little radiological progression, demonstrating the efficacy of surgical treatment for curvature greater than 50°. Curvature greater than 40° was progressive and may require surgery in adulthood. Lumbar scoliosis showed greater potential progression than thoracic scoliosis in adulthood, requiring fusion as of 35° angulation. LEVEL OF EVIDENCE: IV, retrospective study.

[Fishtail deformity after a non-displaced supracondylar humeral fracture in childhood: A case report]. / Hypoplasie de la joue latérale de la trochlée à distance d'une fracture supracondylienne de l'humérus non déplacée chez l'enfant : à propos d'un cas.

We report the case of a 13-year-old boy presenting with stiffness and pain in the elbow, which had appeared a few years before consultation. He reported a history of a closed, nondisplaced supracondylar fracture of the humerus 7 years before. Progression was good after orthopedic treatment. X-rays and CT showed a distinctive deformation, called a fishtail deformity, associated with severe arthritic injuries. We recall here that supracondylar fractures of the humerus are common in children and that early reduction decreases the complication rate. However, this case shows that fishtail deformity is a late and serious complication, which may occur after a nondisplaced supracondylar fracture of the humerus, with no severity factors and with good early progression.

[Improvement of pneumococcal immunization coverage in older patients]. / Amélioration de la couverture vaccinale anti-pneumococcique chez le sujet âgé.

PURPOSE: To study pneumococcal immunization coverage in older patients in hospital, and the impact of two actions aiming at improving this coverage. METHODS: We reported a prospective and descriptive study conducted from November 2009 to August 2010, including all new patients ≥75 years old received in a geriatric short-stay department and residing in Val-de-Marne, France. This study was performed in three successive three-month periods, to assess the vaccination coverage in the months following hospital release. Period I was the reference; Period II included an awareness campaign of general practitioners relying on the hospitalization discharge report, containing an indication for the vaccination; Period III consisted in a systematic proposal of vaccination by the geriatric hospital department. RESULTS: Indication for pneumococcal vaccination has been given to 139 patients (61.2%) in 227 processed questionnaires. The main indication was heart failure for 105 patients (75.5%). Twenty-four patients were already vaccinated (17.2%). No vaccination was reported in the three months following period I in 33 included patients. The awareness campaign targeting regular doctors resulted in only one vaccination out of 37 patients. Immunization coverage in the department had reached 84.5% of inoculation (38 of 45 patients). CONCLUSION: Pneumococcal vaccination is often prescribed in elderly patients but generally not executed. The awareness campaign did not result in a big enough immunization coverage improvement, compared to a codified proposal of vaccination during hospital stay.

Surgery for slipped capital femoral epiphysis in adolescents.

The treatment of slipped capital femoral epiphysis (SCFE) in adolescents remains controversial. The goal of initial treatment is to prevent further slippage of the epiphysis. In mild forms, both stable and unstable, in situ fixation is widely accepted as the reference treatment. In contrast, several techniques are available for stable moderate-to-severe SCFE. In unstable moderate-to-severe SCFE, emergent reduction with decompression and internal fixation is currently the preferred method. Selection of the surgical technique rests on an appraisal of advantages versus drawbacks. The goal of this review is to discuss the various surgical methods available for SCFE in adolescents.

Sacro-iliac joint arthroscopy for arthrodesis after traumatic dislocation. Cadaver and clinical feasibility study.

BACKGROUND: Sacro-iliac arthrodesis usually requires an extended posterior approach, which is associated with a number of dreaded complications. Here, we assessed the feasibility of arthroscopic exploration of the dislocated sacro-iliac joint. MATERIALS AND METHODS: In the first step of our study, we used ligament section to induce loss of sacro-iliac joint coaptation in a cadaver. We then studied 5 patients with Tile C pelvic ring injuries. Arthroscopy was used to clear the joint of fibrous tissue and to roughen the bone to subchondral level in order to induce sacro-iliac arthrodesis. In addition, posterior fixation was performed using a hinge system or an ilio-sacral screw. RESULTS: The cadaver study confirmed the feasibility of sacro-iliac arthroscopy after disruption of the strong posterior inter-osseous ligament. In the clinical part of the study in 5 patients with Tile C pelvic ring injuries, arthroscopy allowed direct visualisation extending to the anterior part of the joint space. A power burr and synovial knife were introduced to remove the interposed fibrous tissue and to roughen the bone to subchondral level in order to induce joint fusion. In addition, percutaneous or open posterior fixation was performed in all 5 patients. No infectious complications were recorded. DISCUSSION: An arthroscope cannot be introduced into the normal sacro-iliac joint. In contrast, after traumatic sacro-iliac dislocation, arthroscopy can be used to evaluate the intra-articular injuries and to roughen the bone to subchondral level.

[Lyme arthritis in children: a diagnostic trap]. / Arthrite de Lyme chez l'enfant : un piège diagnostique.

Lyme disease incidence is diverse in France. It is rare in many regions but very frequent in Central and Eastern France. Arthritis is a late manifestation of Lyme disease. In children, the clinical and biological picture often resembles that of septic arthritis and juvenile rheumatoid arthritis, which are more frequent. This explains why diagnosis may be delayed, especially when patient lives in a region of low incidence. We report the case of an 8-year old girl with knee arthritis treated as septic arthritis in a region where Lyme disease is rare. Six days later, clinical and biological worsening suggested that the diagnosis had to be reconsidered. Lyme arthritis was confirmed by serology. Treatment was adapted and the progression was positive. This case reminds us that, in children, Lyme arthritis may look alike septic arthritis or juvenile rheumatoid arthritis and must be considered as a possible diagnosis, even in low-incidence areas.

Reorganization of the auditory, visual and multimodal areas in early deaf individuals.

Plasticity resulting from early sensory deprivation has been investigated in both animals and humans. After sensory deprivation, brain areas that are normally associated with the lost sense are recruited to carry out functions in the remaining intact modalities. Previous studies have reported that it is almost exclusively the visual dorsal pathway which is affected by auditory deprivation. The purpose of the current study was to further investigate the possible reorganization of visual ventral stream functions in deaf individuals in both the auditory and the visual cortices. Fifteen pre-lingual profoundly deaf subjects were compared with a group of 16 hearing subjects. We used fMRI (functional magnetic resonance imaging) to explore the areas underlying the processing of two similar visual motion stimuli that however were designed to evoke different types of processing: (1) a global motion stimulus (GMS) which preferentially activates regions of the dorsal visual stream, and (2) a form-from-motion (FFM) stimulus which is known to recruit regions from both visual streams. No significant differences between deaf and hearing individuals were found in target visual and auditory areas when the motion and form components of the stimuli were isolated (contrasted with a static visual image). However, increases in activation were found in the deaf group in the superior temporal gyrus (BA 22 and 42) and in an area located at the junction of the parieto-occipital sulcus and the calcarine fissure (encompassing parts of the cuneus, precuneus and the lingual gyrus) for the GMS and FFM conditions as well as for the static image, relative to a baseline condition absent of any visual stimulation. These results suggest that the observed cross-modal recruitment of auditory areas in deaf individuals does not appear to be specialized for motion processing, but rather is present for both motion and static visual stimuli.

Early diagnosis of thoracolumbar spine fractures in children. A prospective study.

INTRODUCTION: Early detection of spine fractures in children is difficult because the clinical examination does not always raise worrisome symptoms and the vertebrae are still cartilaginous, and consequently incompletely visualized on routine X-rays. Therefore, diagnosis is often delayed or missed. HYPOTHESIS: The search for a "breath arrest" sensation at the moment of the trauma improves early detection of thoracolumbar spine fractures in children. MATERIALS AND METHODS: This was a prospective monocentric study including all children consulting at the paediatric emergency unit of a single university hospital with a thoracolumbar spine trauma between January 2008 and March 2009. All children had the same care. Pain was quantified when they arrived using the visual analog scale. Clinical examination searched for a "breath arrest" sensation at the moment of the trauma and noted the circumstances of the accident. X-rays and MRI were done in all cases. RESULTS: Fifty children were included with a mean age of 11.4 years. Trauma occurred during games or sports in 94% of the cases. They fell on the back in 72% cases. Twenty-three children (46%) had fractures on the MRI, with a mean number of four fractured vertebrae (range, 1-10). Twenty-one of them (91%) had a "breath arrest" sensation. Fractures were not visualized on X-rays in five cases (22%). Twenty-seven children had no fracture; 19 of them (70%) did not feel a "breath arrest". Fractures were suspected on X-rays in 15 cases (56%). DISCUSSION: The search for a "breath arrest" sensation at the moment of injury improves early detection of thoracolumbar spine fractures in children (Se=87%, Sp=67%, PPV=69%, NPV=86%). When no fracture is apparent on X-rays and no "breath arrest" sensation is expressed by the child, the clinician can be sure there is no fracture (Se=26%, Sp=100%, PPV=100%, NPV=53%). LEVEL OF EVIDENCE: Level III.

[Open elbow dislocation with distal ischemia: a therapeutic emergency]. / Luxation ouverte du coude avec ischémie distale : une urgence thérapeutique.

We report the case of a 13-year-old boy with a traumatic elbow dislocation, open stage 2 (Cauchoix and Duparc), with distal ischemia. Exposure of the neurovascular humeral bundle through the wound accentutated the clinical emergency. This clinical observation consisted of elbow dislocation with all severity criteria: (i) opening of the skin, (ii) association with a fracture of the medial humeral epicondyle, and (iii) neurological deficit in the territory of the median nerve. The purpose of this report is to remind physicians that no investigation should delay surgery in elbow dislocation. Despite initial distal ischemia, no vascular exploration is required. Early reduction of the disloction is the key point of care.

Functional reorganization of the auditory pathways following late callosotomy.

Injuries at various levels of the auditory system have been shown to lead to functional reorganization of the auditory pathways. In particular, it has recently been shown that such reorganization can occur in callosal agenesis. The pattern of cortical activity following callosotomy is however still unknown, but behavioral results suggest that it could be significantly different from that observed in callosal agenesis. We aimed to confirm this hypothesis by investigating fMRI responses to complex sounds presented binaurally and monaurally in a callosotomized patient. In the binaural condition, the callosotomized subject showed patterns of auditory cortical activation that were similar to those of neurologically intact individuals. However, in both monaural conditions, the callosotomized individual showed a significant increase of the asymmetries favoring the contralateral pathways. Such patterns of cortical responses are only partially consistent with the results obtained from callosal agenesis subjects using the exact same procedure. Indeed, the latter show differences compared with normals in both binaural and monaural conditions. These findings provide neurological evidence that callosotomy could lead to distinctive functional reorganization of the human auditory pathways.

Functional reorganization of the human auditory pathways following hemispherectomy: an fMRI demonstration.

The present study investigated the functional reorganization of ipsilateral and contralateral auditory pathways in hemispherectomized subjects. Functional reorganization was assessed using functional Magnetic Resonance Imaging (fMRI) and stimulation with complex sounds presented binaurally and monaurally. For neurologically intact control subjects, results showed that binaural stimulations evoked balanced activity in both hemispheres while monaural stimulations induced strong contralateral activity and weak ipsilateral activity. The results obtained from hemispherectomized subjects were substantially different from those obtained from control subjects. Specifically, activity in the intact hemisphere showed a significant decrease in response to contralateral stimulation but, concomitantly, an increase in response to ipsilateral stimulation. The present findings suggest that a substantial functional reorganization takes place in the auditory pathways following an early hemispherectomy. The exact nature of this functional reorganization remains to be specified.