Search

Scaffolds are an essential component of bone tissue engineering. They provide support and create a physiological environment for cells to proliferate and differentiate. Bone allografts extracted from human donors are promising scaffolds due to their mechanical and structural characteristics. Bone microarchitecture is well known to be an important determinant of macroscopic mechanical properties, but its role at the microscopic, i.e., the trabeculae level is still poorly understood. The present study investigated linear correlations between microarchitectural parameters obtained from X-ray computed tomography (micro-CT) images of bone allografts, such as bone volume fraction (BV/TV), degree of anisotropy (DA), or ellipsoid factor (EF), and micromechanical parameters derived from micro-finite element calculations, such as mean axial strain (εz) and strain energy density (We). DAEF, a new parameter based on a linear combination of the two microarchitectural parameters DA and EF, showed a strong linear correlation with the bone mechanical characteristics at the microscopic scale. Our results concluded that the spatial distribution and the plate-and-rod structure of trabecular bone are the main determinants of the mechanical properties of bone at the microscopic level. The DAEF parameter could, therefore, be used as a tool to predict the level of mechanical stimulation at the local scale, a key parameter to better understand and optimize the mechanism of osteogenesis in bone tissue engineering.

BACKGROUND: Clinical examination is the gold standard for surgical indication. Electromyogram and conventional MRI are insufficient to understand the highly variable clinical presentation of neonatal brachial plexus (BP) lesions. Diffusion Tensor Imaging is based on motion of water molecules and can explore nerve function. PURPOSE: This pilot study of healthy subjects aimed to develop a new method for BP exploration using MRI. The main objective was to obtain complete and accurate BP mapping using DTI and MRI tractography. METHODS: Six healthy volunteers had MRI (3T PRISMA) with anatomical 3D STIR, SPACE and RESOLVE diffusion sequences. Image analysis and processing was performed with MATLAB software. Diffusion parametric maps of fractional anisotropy (FA) were extracted from RESOLVE acquisitions. A reproducible method for root volume and angle measurements was created using 3DSlicer. Regions Of Interest were segmented on Mean B0 sequences. FA measurements were obtained with ROI on Mean B0 sequences. RESULTS: RESOLVE sequence was adapted to the BP. Mean FA was 0.30. Angle measurements on 3D STIR SPACE sequences showed increasing values from proximal to distal roots with an ICC of 0.6. Volume measurements on anatomical sequences varied widely from one root to another but no significant difference was shown on laterality. CONCLUSION: A new and reproducible method for BP exploration was developed using MRI RESOLVE diffusion sequences. Complete mapping was obtained despite low track density imaging resolution. The whole BP was visualized. Extraction of diffusion, volume and angle parameters of the plexus roots, and script creation for image processing was adapted to the healthy BP.

Objective: The main objective of this study was the development of a non-invasive mathematical marker of the skin surface, the characteristic length, to predict the microstructure of the dermis. This marker, at the individual level, is intended to provide the biological age of the patient in the context of personalised medicine for the elderly. Study design: To validate this hypothesis, a clinical study was conducted on 22 women over 60 years old from a population of osteoporotic subjects who sustained a femoral neck fracture: a morphological analysis of the skin surface was performed on the patient’s forearm and quantitatively compared with microarchitectural parameters of the dermis. Major results: The Elastin-to-Collagen ratio measured on dermis samples ranged between 0.007 and 0.084, with a mean of 0.035 ± 0.02. The surface characteristic length ranged between 0.90 and 2.621, with a mean of 0.64 ± 0.51. A very strong correlation was found between this characteristic length and the Elastin-to-Collagen ratio (r = 0.92). Conclusions: This study proposes an original diagnostic tool based on morphometric indices of the skin surface and shows a direct quantitative relationship with the dermis microarchitecture and its collagen and elastin content. The proposed method allows reliable and easy access to the intrinsic ageing of the dermis, which would be a strong biomarker in a personalised collagen treatment approach.

Resume Introduction Le transfert d’epiphyse proximale vascularisee de fibula associe a un segment de diaphyse permet de traiter les pertes de substances epiphysaires de l’enfant. L’objectif de cette etude est d’analyser la technique chirurgicale, puis les resultats cliniques et radiologiques a long terme. Materiel et methode Entre 1997 et 2008, 7 patients, âges en moyenne de 5,7 ans (2–8), ont ete operes d’une tumeur osseuse maligne avec reconstruction par transfert d’epiphyse vascularisee de fibula : 5 sarcomes d’Ewing et 2 osteosarcomes, localises au femur proximal (3), a l’humerus proximal (3) et au radius distal (1). Le transplant mesurait en moyenne 13,8 cm. La vascularisation etait assuree par un pedicule unique dans 5 cas (fibulaire : 3 ; tibial anterieur : 2) et par deux pedicules dans 2 cas. L’osteosynthese etait realisee par une broche centromedullaire dans 6 cas et une plaque vissee dans 1 cas. Tous les patients ont eu une chimiotherapie pre- et postoperatoire selon les protocoles de la societe francaise d’oncologie pediatrique. Resultats Le recul moyen etait de 11 ans (de 3 ans et 11 mois a plus de 17 ans). Tous les patients etaient vivants et en remission de leur tumeur. La fonction de l’articulation reconstruite etait jugee satisfaisante dans 85 % des cas. L’epaississement du greffon traduisait son integration dans tous les cas. La physe transferee avait repris sa croissance dans 4 cas. Parmi les complications, on notait une infection postoperatoire, deux defauts de consolidation, 8 fractures, une desaxation necessitant une reprise chirurgicale et deux paralysies spontanement regressives du nerf fibulaire commun. Discussion Chez les petits enfants, le transfert de fibula vascularisee avec son epiphyse est une technique qui permet a la fois de combler une perte de substance osseuse, de reconstruire une articulation mobile et de permettre la poursuite de la croissance du segment reseque. Les protheses de croissance, selon l’experience des auteurs, ont regulierement donne de mauvais resultats dans cette tranche d’âge et les arthrodeses ne reglent pas le probleme de la croissance. Il semble important de prevenir les patients du risque de fracture pouvant survenir, meme a long terme. Conclusion Le transfert d’epiphyse vascularisee est une technique difficile, grevee de complications, mais qui permet de reconstruire un segment osseux emportant une epiphyse chez le petit enfant, conservant ainsi une fonction et une croissance. Niveau d’evidence III, etude clinique retrospective.

Introduction Vascularized fibular proximal epiphyseal transfer associated to a diaphyseal segment is used to treat childhood epiphyseal defect. The aim of the present study was to analyze surgical technique and long-term clinical and radiological results. Material and method Between 1997 and 2008, 7 patients with a mean age of 5.7 years (range, 2-8 years) were operated on for bone malignancy with vascularized fibular epiphyseal transfer: 5 Ewing sarcomas and 2 osteosarcomas, located in the proximal femur (n = 3), proximal humerus (n = 3) or distal radius (n = 1). Mean transplant size was 13.8 cm. Vascularization involved a single artery in 5 cases (3 peroneal, 2 anterior tibial) and both in 2 cases. Internal fixation used intramedullary nailing in 6 cases and screwed plate in 1. All patients underwent pre- and post-operative chemotherapy following French Pediatric Oncology Society (SFOP) protocols. Results Mean follow-up was 11 years (range, 3 years 11 months to > 17 years). All patients were alive and in tumor remission. Reconstructed joint function was satisfactory in 85% of cases. Graft thickening indicated integration in all cases. The transferred cartilage had recovered growth in 4 cases. Complications comprised postoperative infection (n =1), consolidation defects (n = 2), fractures (n = 8), malalignment requiring surgical revision (n = 1), and spontaneously resolving common peroneal nerve palsies (n = 2). Discussion In young children, vascularized fibular epiphyseal transfer fills bone defect, reconstructs a functional joint and allows continued growth in the resected segment. Growth prostheses, in the authors’ experience, always give poor results in this age-group, and fusion fails to address the growth problem. Patients should be informed about the risk of fracture, persisting over the long term. Conclusion Vascularized fibular epiphyseal transfer is a difficult technique, subject to complications, but enables reconstruction of a bone segment involving the epiphysis in young children, conserving function and growth. Level of evidence III, retrospective clinical study.

Background Amputation of the abnormal segment seems to be the reference standard treatment for the surgical management of macrodactyly of the foot in children. Our objectives here were to detail the surgical strategies according to the cause, anatomical characteristics, and static or progressive nature of the macrodactyly and to evaluate the long-term clinical outcomes. Hypothesis Conservative treatment can be an option in the management of static macrodactyly of the foot in children. Material and methods We retrospectively included 24 feet in 19 patients seen consecutively. There were 12 primary and 12 secondary types. The macrodactyly was static in 9 cases and progressive in 15 cases. The treatment consisted in either conservative procedures or amputation of the segment. All patients completed the Oxford Ankle Foot Questionnaire for Children (OxAFQ-C) to evaluate their quality of life, shoe wear issues, and satisfaction with their treatment. Results Mean age at first surgery was 5.8 years (range, 0.5–11.5) and the mean interval between two procedures was 2.3 years (range, 0.3–5.5). Mean number of procedures per foot was 2.2 par pied (range, 0–7). All 9 static forms were managed conservatively. Amputation was performed in 11 of the 15 progressive forms. The mean number of procedures was significantly higher in the progressive forms (4.1 vs. 1.5/pied; p = 0.006). Two patients died during follow-up. The remaining 17 patients, with 22 affected feet (primary and secondary in 11 cases; progressive in 14 cases and static in 8 cases) were re-evaluated. Mean follow-up was 9.4 years (range, 2.7–20.6). The final OxAFQ-C score was 46/60 (range, 18–58). Of the 17 patients, 86% would be willing to repeat the same surgical procedures and 77% were satisfied with their treatment at last follow-up. We found no differences between the groups managed with amputation and with conservative treatment regarding quality of life, satisfaction, or shoe size difference. Conclusions Conservative treatment deserves a place in the treatment of static macrodactyly of the foot in children. Regarding amputation of the segment in progressive forms, it is important to reassure the patients and parents about the expected results but also to inform them about the risk of requiring repeat surgical procedures. Level of evidence IV, retrospective study.

Introduction Three-dimensional (3D) planning and patient-specific surgical guides are increasingly used in the treatment of skeletal deformities. The present study hypothesis was that they are reliable in forearm osteotomy in children, with low morbidity. Material and methods Twenty-there children with one or several osteotomies to correct forearm deformities were retrospectively included: 9 (20 osteotomies) with surgical guide (G+), and 14 (28 osteotomies) without (G-). Etiologies comprised 8 cases of Madelung disease (3G+, 5G−) and 15 of post-traumatic malunion (6G+, 9G−). Mean age at surgery was 14.8 ± 1.9 years. The patient-specific 3D-printed polyamide guides were produced from 3D virtual models based on 3D CT reconstruction. Mean follow-up was 22.1 ± 13.6 months. Results Mean correction error was 5.3° ± 4.1 and 4.2° ± 4.1 in the frontal and sagittal planes respectively in G+ (p = 0.6). Surgery time was significantly shorter in G+, by a mean 42 min (p = 0.02). Mean total radiation dose (preoperative CT + intraoperative fluoroscopy) was significantly higher in G+ (p Conclusion The present preliminary results were encouraging. 3D planning and patient-specific surgical guides can be used in the treatment of forearm deformity in children. Level of evidence III; retrospective cohort study.

Background: In more than 50% of cases, anterior cruciate ligament (ACL) lesions lead to post-traumatic osteoarthritis. Ligament reconstruction stabilizes the joint, but the tear seems to impair the poroelasticity of the cartilage: synovial membrane fluid inflammation is observed 3 weeks after tearing. There have been some descriptions of visible cartilage changes, but poroelasticity has never been analyzed at this early stage. The present animal study aimed to determine 1) whether cartilage showed early poroelastic deterioration after ACL tear; 2) whether impairment correlated with macroscopic changes; and 3) whether cartilage poroelasticity deteriorated over time. Hypothesis: In the days following trauma, cartilage poroelasticity is greatly impaired, without macroscopically visible change. Material and methods: ACL tear was surgically induced in 18 New-Zealand rabbits. Cartilage poroelasticity was assessed on indentation-relaxation test in 3 groups: “early”, at 2 weeks postoperatively (n=6), “mid-early” at 6 weeks (n=6) and in a non-operated control group (“non-op”). Macroscopic changes were scored in the same groups. Results: Poroelastic impairment was greatest at the early time-point (2 weeks). Permeability ranged from a mean 0.08±0.05x10-15 m4/Ns (range, 0.028-0.17) in the “non-op” group to 1.03±0.60x10-15 m4/Ns (range, 0.24-2.15) in the “early” group (p=0.007). Shear modulus ranged from 0.53±0.11 MPa (range, 0.36-0.66) to 0.23±0.10 MPa (range, 0.12-0.43), respectively (p=0.013). Macroscopic deterioration, on the other hand, differed significantly only between the “mid-early” and the “non-op” groups: p=0.011 for cartilage deterioration and p=0.008 for osteophyte formation. At the “mid-early” time point, poroelastic deterioration was less marked, with 0.33±0.33x10-15 m4/Ns permeability (range, 0.06-1.06) and shear modulus 0.30±0.10 MPa (range, 0.13-0.41: respectively p=0.039 and p=0.023 compared to the “non-op” group. Discussion: The severe rapid deterioration in poroelasticity following ACL tear in an animal model, as notably seen in increased permeability, corresponds to changes in cartilage microstructure, with easier outflow of interstitial fluid. This mechanical degradation may underlie onset of microcracks within the cartilage, leading to physiological loading that the cartilage by its nature is unable to repair. Further investigations are needed to correlate these experimental data with clinical findings. Level of evidence: III; comparative study with control group.

Tissue-engineered grafts may be useful in Anterior Cruciate Ligament (ACL) repair and provide a novel, alternative treatment to clinical complications of rupture, harvest site morbidity and biocompatibility associated with autografts, allografts and synthetic grafts. We successfully used supercritical carbon dioxide (Sc-CO2) technology for manufacturing a “smart” biomaterial scaffold, which retains the native protein conformation and tensile strength of the natural ACL but is decellularized for a decreased immunogenic response. We designed and fabricated a new scaffold exhibiting (1) high tensile strength and biomechanical properties comparable to those of the native tissue, (2) thermodynamically-stable extra-cellular matrix (ECM), (3) preserved collagen composition and crosslinking, (4) a decellularized material milieu with potential for future engineering applications and (5) proven feasibility and biocompatibility in an animal model of ligament reconstruction. Because of the “smart” material ECM, this scaffold may have the potential for providing a niche and for directing stem cell growth, differentiations and function pertinent to new tissue formation. Sc-CO2-related technology is advanced and has the capability to provide scaffolds of high strength and durability, which sustain a lifetime of wear and tear under mechanical loading in vivo.

Purpose: The aim of this study was to compare the radiation dose, image quality and 3D spine parameter measurements of EOS low-dose and micro-dose protocols for in-brace adolescent idiopathic scoliosis (AIS) patients. Methods: We prospectively included 25 consecutive patients (20 females, 5 males) followed for AIS and undergoing brace treatment. The mean age was 12 years (SD 2 years, range 8-15 years). For each patient, in-brace biplanar EOS radiographs were acquired in a standing position using both the conventional low-dose and micro-dose protocols. Dose area product (DAP) was systematically recorded. Diagnostic image quality was qualitatively assessed by two radiologists for visibility of anatomical structures. The reliability of 3D spine modeling between two operators was quantitatively evaluated for the most clinically relevant 3D radiological parameters using intraclass correlation coefficient (ICC). Results: The mean DAP for the posteroanterior and lateral acquisitions was 300 ± 134 and 433 ± 181 mGy cm2 for the low-dose radiographs, and 41 ± 19 and 81 ± 39 mGy cm2 for micro-dose radiographs. Image quality was lower with the micro-dose protocol. The agreement was "good" to "very good" for all measured clinical parameters when comparing the low-dose and micro-dose protocols (ICC > 0.73). Conclusion: The micro-dose protocol substantially reduced the delivered dose (by a factor of 5-7 compared to the low-dose protocol) in braced children with AIS. Although image quality was reduced, the micro-dose protocol proved to be adapted to radiological follow-up, with adequate image quality and reliable clinical measurements. These slides can be retrieved under Electronic Supplementary Material. No funding was secured for this study.

Tendon lengthening and transfer are usually indicated for certain neuromuscular disorders, peripheral or central nerve injury, congenital disorder or direct traumatic or degenerative musculotendinous lesion. In musculotendinous lengthening, technique depends on muscle anatomy, degree of correction required, and the need to avoid excessive loss of force. Lengthening within the muscle or aponeurosis is stable. In the tendon, however, it may provide greater gain but is not stable and requires postoperative immobilization to avoid excessive lengthening. Tendon transfer consists in displacing a muscle's tendon insertion in order to restore function. The muscle to be transferred is chosen according to strength, architecture and course, contraction timing, intended direction, synergy and the joint moment arm to be restored. Functions to be restored have to be prioritized, and alternatives to transfer should be identified. The principles of tendon transfer require preoperative assessment of the quality of the tissue through which the transfer is to pass and of the suppleness of the joints concerned. During the procedure, transfer tension should be optimized and the neurovascular bundle should be protected. The method of fixation, whether tendon-to-bone or tendon-to-tendon suture, should be planned according to local conditions and the surgeon's experience.

OBJECTIVE: To determine whether the seasonal distribution of Kingella kingae osteoarticular infections is similar to that of common respiratory viruses. STUDY DESIGN: Between October 2009 and September 2016, we extracted the results of K kingae-specific real-time polymerase chain reaction analyses performed for bone or joint specimens in patients from 2 pediatric tertiary care centers in Paris. We used data of respiratory virus detection from the Réseau National des Laboratoires network with coordination with the National Influenza Center of France. The Spearman rank correlation was used to assess a correlation between weekly distributions, with P

Scoliosis surgery may be associated with a high morbidity and even mortality in children with non-idiopathic scoliosis. The aim of the study was to report our experience with a pre-operative training to non-invasive positive pressure ventilation (NPPV) and a mechanical insufflator-exsufflator (MI-E) device to improve the post-operative respiratory outcome of children scheduled for scoliosis surgery.Consecutive patients with non-idiopathic scoliosis undergoing posterior arthrodesis were trained to NPPV and MI-E before intervention. NPPV and MI-E were performed immediately after extubation. Length of intubation and intensive care unit (ICU) stay, duration of NPPV, and respiratory complications were assessed.Thirteen patients participated in the training (mean age 13.9 ± 2.6, mean vital capacity 52.3 ± 15.4% predicted). The patients had severe respiratory muscle weakness with a mean sniff oesophageal pressure of 35.8 ± 14.2 cmH2O (50% predicted) and a mean gastric pressure during a cough of 31.9 ± 7.8 cmH2O (30% predicted). The mean length of intubation was 19.9 ± 12.3 h with a mean length of ICU stay of 2.5 ± 2.5 days. NPPV was used during a mean of 2.7 ± 1.9 days after surgery. No respiratory complication was observed. One patient died 3 months after surgery from multi-organ failure of non-respiratory origin.No respiratory complications were observed after scoliosis correction surgery in children with non-idiopathic scoliosis after pre-operative training and post-operative use of NPPV and MI-E, underlying the interest of this management in these high-risk patients.

International audience; Purpose: Scoliosis with pelvic obliquity (PO) could be investigated with the EOS-CHAIR protocol as the most common deformity especially in patients with trunk hypotonia and quadriplegia. However, the intra-observer and inter-observer reliability of various angles assessing PO was not investigated with this new imaging protocol.Methods: A retrospective cohort of 36 EOS frontal full-spine acquisitions made in sitting position was used. The sacroiliac pelvic obliquity angle, iliac crest pelvic obliquity angle, and ischiatic pelvic obliquity angle were assessed in an intra-observer and inter-observer study.Results: The use of the EOS-CHAIR protocol was implemented satisfactory with a high acceptance rate by all caregivers and patients and their families. Intra-observer and inter-observer reliability was excellent for the three tested angular measurements.Discussion: As for idiopathic scoliosis, we postulate the EOS system as being superior to standard radiographs to assess 3D spinal deformities in neuromuscular conditions. The EOS-CHAIR protocol improves preoperative comprehension of the lumbosacral junction anatomy in patients with poor standing or sitting postures. Our results show a very high reliability of three different angular measurements of the frontal pelvic obliquity in sitting position. Then it is possible to use one of these three angles as well as the others to assess frontal pelvic obliquity in neuromuscular patients. This frontal pelvic obliquity protocol in sitting position with the EOS-CHAIR is a validated measurement technique that needs to be used now to measure PO as a critical parameter of the global trunk balance in neuromuscular patients.

International audience; Recently, it has been shown that constructs of poly(vinyl alcohol) (PVA) hydrogel fibers reproduce closely the tensile behavior of ligaments. However, the biological response to these systems has not been explored yet. Here, we report the first in vivo evaluation of these implants and focus on the integration in bone, using a rabbit model of bone tunnel healing. Implants consisted in bundles of PVA hydrogel fibers embedded in a PVA hydrogel matrix. Half of the samples were coated with a composite coating of hydroxyapatite (HA) particles embedded in PVA hydrogel. The biological integration was evaluated at 6 weeks using histology and micro-CT imaging. For all implants, a good biological tolerance and growth of new bone tissue are reported. All the implants were surrounded by a fibrous layer comparable to what was previously observed for poly(ethylene terephthalate) (PET) fibers currently used in humans for ligament reconstruction. An image analysis method is proposed to quantify the thickness of this fibrous capsule. Implants coated with HA were not significantly osteoconductive, which can be attributed to the slow dissolution of the selected hydroxyapatite. Overall, these results confirm the relevance of PVA hydrogel fibers for ligament reconstruction and adjustments are proposed to enhance its osseointegration.

International audience; Pedicle screw fixation allows purchase of all three spinal columns without encroaching into the spinal canal improving fracture fixation, as well as deformity correction. Fortunately, neurologic injury associated with pedicle screw malposition is rare.Case presentationA 19-year-old boy was surgically treated for severe right thoracic scoliosis associated with a Chiari Type 1 malformation and a C6 to T7 syringomyelia. Six months after the initial surgery, the patient was referred to our institution after three weeks of gait disturbances and repeated falls. Imaging showed the gross misplacement of the left T5 pedicle screw, which crossed the center of the vertebral canal. The initial surgery used a freehand technique of pedicle screw insertion, with anteroposterior and lateral postoperative X-ray control. During the surgery, no SEP modifications were noted during pedicle screw placement. However, after insertion of the second rod and scoliosis correction by posterior translation technique, SEP responses decreased considerably. Revision surgery was performed to remove the misplaced screw. During the first three months after screw removal, repeated clinical examinations showed progressive recovery of the neurological deficits. Gait and bladder functions were normal six months after screw removal, and clinical signs of spasticity disappeared. SEP explorations performed at final follow-up showed similar responses to those performed before the initial surgery for scoliosis correctionDiscussion and evaluationNeurologic injury associated with pedicle screw malposition is rare. In early or delayed neurological status worsening, intraoperative or postoperative imaging must be done to detect pedicle screw misplacement. In the current case, thanks to cobalt-chromium and titanium use, MRI and CT scan allowed good visualization of the spinal canal and spinal cord. Experimental studies have shown that neurophysiological monitoring of the spinal cord does not detect moderate compression. In that way, neurophysiological monitoring is an all-or-nothing technique which can misdiagnose early stage of spinal cord injuries. Major penetration of the spinal canal by pedicle screw may conduct to hardware removal.ConclusionsIn early or delayed neurological status worsening, intraoperative or postoperative imaging must be done to detect pedicle screw misplacement. In the current case, thanks to cobalt-chromium and titanium use, MRI and CT scan allowed good visualization of the spinal canal and spinal cord. Major penetration of the spinal canal by pedicle screw may conduct to hardware removal.

Purpose Magnetic resonance imaging (MRI) has been successfully used in the determination of the adequacy of the surgical reduction of congenitally dislocated hips in children. We present the results of a prospective series of patients treated conservatively. MRI was performed in all hips after positioning was deemed adequate on radiographs after spica cast application. The goal of this study was to evaluate the usefulness of MRI in this indication. Methods After the study was approved by our local ethics committee, 31 patients for a total of 36 dislocated hips were included. After the traction period, hip testing was performed and a hip spica cast was applied under general anaesthesia. All children had MRI within 1 week of reduction, without the need for contention or general anaesthesia. Hip reduction was assessed on axial and coronal MRI images. Results The concentric reduction of the hip was confirmed in 30 cases out of 36. In three cases, the dislocation was retrospectively suspected on radiographs and then confirmed. In the three remaining cases, hip dislocation was only diagnosed on MRI. Conclusions MRI screening of congenitally dislocated hips after reduction procedures is a safe and reliable procedure to assess the concentric reduction of the hip. Even in doubtful cases, MRI detected persistent hip dislocations and was conducive to iterative reduction and satisfactory outcome and result.

Background Tissue engineering strategies include both cell-based and cell homing therapies. Ligamentous tissues are highly specialized and constitute vital components of the musculoskeletal system. Their damage causes significant morbidity and loss in function. Hypothesis The aim of this study is to analyze tendinous graft integration, cell repopulation and ligamentization by using GFP+/– allografts in GFP+/– transgenic New Zealand white (NZW) rabbits. Material and methods Graft implantation was designed to closely mimic anterior cruciate ligament (ACL) repair surgery. Allografts were implanted in 8 NZW rabbits and assessed at 5 days, 3 weeks and 6 weeks through: (1) arthroCT imaging, (2) morphological analysis of the transplanted allograft, (3) histological analysis, (4) collagen type I immunochemistry, and (5) GFP cell tracking. Collagen remodeling was appreciated at 3 and 6 weeks. Results Graft repopulation with host cells, chondrocyte-like cells at the tendon-bone interface and graft corticalization in the bone tunnels were noticed at 3 weeks. By contrast we noticed a central necrosis aspect in the allografts intra-articularly at 6 weeks with a cell migration towards the graft edge near the synovium. Discussion Our study has served to gain a better understanding of tendinous allograft bone integration, ligamentization and allograft repopulation. We believe that both cell-based therapies and cell homing therapies are beneficial in ligament tissue engineering. Future studies may elucidate whether cell repopulation occurs with pre-differentiated or progenitor cells. We believe that both cell-based therapies and cell homing therapies are beneficial in ligament tissue engineering. Level of evidence Level V (animal study).

OBJECT Spinopelvic alignment is crucial in assessing an energy-efficient posture in both normal and disease states, such as high-displacement developmental spondylolisthesis (HDDS). The overall effect in patients with HDDS who have undergone local surgical correction of lumbosacral imbalance for the global correction of spinal balance remains unclear. This paper reports the progressive spontaneous improvement of global sagittal balance following surgical correction of lumbosacral imbalance in patients with HDDS. METHODS The records of 15 patients with HDDS who underwent surgery between 2005 and 2010 were reviewed. The treatment consisted of L4–sacrum reduction and fusion via a posterior approach, resulting in complete correction of lumbosacral kyphosis. Preoperative, 6-month postoperative, and final follow-up postoperative angular measurements were taken from full-spine lateral radiographs obtained with the patient in a standard standing position. Radiographic measurements included pelvic incidence, sacral slope, lumbar lordosis, and thoracic kyphosis. The degree of lumbosacral kyphosis was evaluated by the lumbosacral angle. Because of the small number of patients, nonparametric tests were considered for data analysis. RESULTS Preoperative lumbosacral kyphosis and L-5 anterior slip were corrected by instrumentation. Transient neurological complications were noted in 5 patients. Statistical analysis showed a significant increase of thoracic kyphosis on 6-month postoperative and final follow-up radiographs (p < 0.001). A statistically significant decrease of lumbar lordosis was noted between preoperative and 6-month control radiographs (p < 0.001) and between preoperative and final follow-up radiographs (p < 0.001). CONCLUSIONS Based on the authors' observations, this technique resulted in an effective reduction of L-5 anterior slip and significant reduction of lumbosacral kyphosis (from 69.8° to 105.13°). Due to complete reduction of lumbosacral kyphosis and anterior trunk displacement associated with L-5 anterior slipping, lumbar lordosis progressively decreased and thoracic kyphosis progressively increased postoperatively. Adjusting the sagittal trunk balance produced not only pelvic anteversion, but also reciprocal adjustment of lumbar lordosis and thoracic kyphosis, creating a satisfactory level of compensated global sagittal balance.

BACKGROUND: Multiple distraction strategies have been proposed to reduce the incidence of anxiety and pain in children. Animal-assisted therapy is acknowledged and used in children as an adjunctive treatment with cognitive, physical, psychosocial and spiritual benefits.OBJECTIVE: To determine the effect of fish aquarium animal-assisted therapy (FA-AAT) on pain perception in a cohort of healthy volunteers.METHODS: Sixty-nine healthy subjects (mean age 27.3 years) were exposed to >20 different species of soft or hard corals and >25 fish in a 1000 L saltwater aquarium. Pain perception was assessed using an electrical stimulation device, the Pain Matcher (Cefar Medical AB, Sweden), after 5 min, 10 min, 20 min and 30 min of continuous aquarium viewing. The measurements were repeated 10 min after stopping aquarium viewing.RESULTS: A statistically significant pain perception threshold augmentation was observed after a 5 min aquarium viewing. This threshold augmentation was also increased after 10 min, 20 min and 30 min of FA-AAT. A remnant effect was noted up to 10 min after exposure. This short post-viewing time period could be useful in clinical practice to perform certain painful procedures in children, such as those involving needles, under improved conditions immediately after aquarium exposure.CONCLUSIONS: In the authors’ department, FA-AAT is now used as a nonpharmacological antinociceptive technique in association with a protocol of inhalated oxygen/nitrous oxide mixtures for needle-related procedures. Children and parents are invited to watch the aquarium during the 10 min to 20 min before venous punctures.

Objectives Both bone forearm fractures are efficiently treated by elastic stable intramedullary nail (ESIN). According to the original technique, the tip of the nail must be bent at 90° and buried under the skin. However, skin irritation is commonly reported and may lead to early surgery to shorten the tip or remove the hardware. The purpose of this study was to investigate the influence of the bending of the tip of the nail in this procedure. Methods We retrospectively reviewed 72 children operated on using this technique with the tip bent either at 90° or at 180°. In both groups we recorded complication rates after the procedure and at the removal. Results Time until removal and duration of the removal were similar in both groups. Three complications (6.7%) that required additional surgery were recorded when the tip was bent at 90° whereas no complications were found with the tip bent at 180°. Conclusion We advocate bending the tip of the nail at 180° before burying it in order to avoid skin irritation and additional procedures. Level of evidence Level III—retrospective comparative study.

Pedicle screw fixation is considered biomechanically advantageous in adolescent idiopathic scoliosis (AIS) correction, because it uses as an anchor the pedicle, which is the hardest part of the vertebral body. The ability of the rod to correct and hold the correction is a key factor in the selection of rod material. The goal of this study was to compare the results obtained by stainless steel (SS) and cobalt–chromium (CoCr) rods materials for the treatment of AIS curves. Ninety patients were retrospectively included. Sixty-four patients (group 1) were operated on using CoCr rods. Twenty-six patients (group 2) were operated on using SS rods. All the patients were treated by the same surgeon using all-pedicle screw constructs. In group 1, the correction was respectively 41.03° and 35.78° for main and secondary curves. In group 2, the correction was respectively 30.98° and 24.42° for main and secondary curves. Statistical analysis showed improved correction rates in patients operated with CoCr rods for main (P

Infection after spinal fusion for scoliosis is a commonly reported complication. Although techniques in paediatric spinal fusion have improved with regard to infection prophylaxis, postoperative infection rates range from 0.4% to 8.7%.The rate of infection in surgery for adolescent idiopathic scoliosis (AIS) has ranged from 0.9% to 3%. The rate of infection in spinal surgery for deformity related to myelomeningocele has been reported to be from 8% to 24%. The rate of infection in spinal surgery for deformity related to cerebral palsy has been reported to be from 6.1% to 8.7%. Infection after spinal fusion for scoliosis related to a muscular dystrophy is generally less frequent. Despite a large number of cases and studies, the literature did not provide documentation of several factors that may be related to the occurrence of wound infection. The rate of wound infection after spine surgery is dependent on many factors, including the complexity of the procedure, health status of the patient, and potentially the experience and technique of the operating surgeon.The general algorithm for treatment depends on a variety of factors, including the delay from the index procedure, the infecting organism, the location and extent of the infection, the gross appearance of the fusion mass, and the surgical strategy used to correct the initial deformity. For infections that develop within the first 90 days after the index procedure all attempts to retain the instrumentation should be made. In late infections, the fusion mass must be carefully inspected before instrumentation removal is considered. Although fusion may appear to be solid both radiographically and intra-operatively, there still may be the possibility of loss of correction at last follow-up.Deep wound infection after instrumented fusion of the spine remains a difficult and challenging clinical problem and entails substantial morbidity, cost, and recovery time for the patient. An aggressive approach to deep wound infection emphasising early irrigation and debridement allowed preservation of instrumentation and successful fusion in most cases. At the conclusion of treatment, patients can expect a medium-term clinical outcome similar to patients in whom infectious complication did not occur.

Summary Purpose Assessing functional outcome from patient-based outcomes questionnaires are essential to the evaluation of adolescent idiopathic scoliosis surgical treatment Methods At the minimum follow-up of 2 years, 45 operated on adolescent idiopathic scoliosis patients were mailed the French version of the Scoliosis Research Society Outcome Instrument (SRS-22) questionnaires containing items on pain, activities of daily living, and satisfaction. Results Mean values of the SRS-22 domains were 3,66 for the Pain domain, 3,85 for the Self-perceived image domain, 4,32 for the Function domain, 3,52 for the Mental health domain and 4,12 for the Global satisfaction with management domain. Mean value of the global SRS-22 score was 3,88. We showed no differences in functional SRS-22 health status in patients according to the type of curve (Lenke classification). We showed statistically significant correlations between the gain of Cobb angle and Patients self-image and function domain scores. There was a statistically significant correlation between preoperative Cobb angle and patient satisfaction with management. Conclusions Even if Function and Self-image scores in our patients are close to control group values, indicating good short to mid-term outcome of surgical treatment, scores for pain and mental health status were significantly lower in patients than controls. Long-term follow-up studies conducted by multiple surgeons over successive generations are mandatory to assess clinical significance of these differences. Level of evidence Level IV. Retrospective study

Background Various methods regarding allograft knee replacements have been described. The animal models, which are generally used for this purpose include sheep, dogs, goats, and pigs, and accrue significant costs for study protocols. The authors herein describe an efficient and cost-effective model to study either native or tissue-engineered allografts for anterior cruciate ligament (ACL) replacement in a New Zealand rabbit model with the potential for transgenic and cell migration studies. Methods ACL reconstructions were performed in rabbits under general anesthesia. For fresh allograft implantations, two animals were operated in parallel. Each right extensor digitorum longus tendon was harvested and prepared for implantation. After excision of the ACL, tibial and femoral bone tunnels were created to implant each graft in the native ACL position. Results During a 2-year period, the authors have successfully undertaken this surgery in 61 rabbits and have not noticed any major complications attributed to this surgical technique. In addition, the authors have observed fast recovery in the animals postoperatively. Conclusion The authors recommend this surgical procedure as an excellent model for the study of knee surgery.