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In this work numerical calculations are performed to study thermal radiation effects on heat transfer for combustion products (H2O-CO2-N2) flowing inside circular ducts. Combined heat transfer, by thermal radiation and forced convection is presented in some cases of practical situations such as combustion of natural gas, propane and heavy fuel. Special attention was paid to the treatment of real gaseous mixture thermal radiation, with its spectral nature, and their effects on evolution of radiative, convective and conductive fluxes for a steady laminar flow. The infrared radiative properties of the flowing H2O-CO2-N2 gas mixtures are taken into account in this analysis by using the global Absorption Distribution Function model. Some differences between non gray radiative behaviors of these combustion products, due to different structures of their spectra, are put in evidence through the evolution of the volumetric radiative power. The flow and energy balance equations are solved simultaneously with temperature dependent fluid properties. The approximations of a boundary layer flow are made, except for radiative transfer. The results are presented for typical conditions of combustion products flows. It is shown that radiative transfer affects significantly the different heat fluxes exchanged, and thus the Nusselt number and bulk temperatures. [ABSTRACT FROM AUTHOR]

Introduction: Pediatric idiopathic pes planovalgus can correct itself with growth. Otherwise, in the event of functional impairment and after failed conservative treatment, surgery can be considered. Based on a multicenter retrospective study, we report the functional and radiographic results obtained after subtalar arthroereisis., Hypothesis: We hypothesized that this surgery improves functional and radiological parameters in childhood., Material and Method: Forty-eight medical records of children (78 feet) operated on between 2010 and 2019 were studied. Functional (FAOS score) and radiographic (Djian angle, calcaneal slope, lateral talocalcaneal divergence and calcaneus/M5 alignment, talonavicular coverage measurement, AP talocalcaneal divergence) results were studied. The analysis of these different criteria was carried out between the preoperative period and the last follow-up., Results: The functional outcome was satisfactory with an average FAOS questionnaire score of 95.5 out of 100 total points. All the radiographic parameters studied were significantly improved (p<0.001). The average age at the time of surgery was 11.3 years (range: 7 to 16) with a mean follow-up of 35 months (range: 18 months to 84). Spontaneous screw expulsion and subtalar pain were the main complications found., Discussion: The results obtained are consistent with those in the literature. The age at the time of the surgery is an essential factor to consider with the goal of optimal correction., Conclusion: This technique is reliable and effective in the short term. It can be offered as first-line therapy in the management of symptomatic pes planovalgus in children. The follow-up is short, which necessitates longer term studies of this population. The ideal age for surgery remains to be determined., Level of Evidence: IV., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

Purpose: This study aims to examine whether Pridie drilling, a form of bone marrow stimulation, can expedite the healing process and enable a faster return to sports activity in patients with knee Osteochondritis dissecans (OCD). The primary objective is to assess the effectiveness of Pridie drilling in stable OCD lesions that do not respond to non-operative treatment, by evaluating the absence of painful symptoms 6 months after the procedure. Secondary objectives include evaluating radiographic reconstruction 6 months post-surgery and determining the time it takes to resume sports participation., Materials and Methods: This single-center retrospective study included all cases of stable OCD in the knee that underwent anterograde chondral drilling between 2008 and 2020. Diagnosis of OCD was established using knee radiographs, and the surgical technique involved multiple multidirectional subchondral drilling. Treatment efficacy was defined by the absence of painful symptoms for 6 months postoperatively., Results: A total of 41 knees were included in the study, and no complications were observed before or after surgery. At 6 months postoperatively, 32 knees (78%) showed complete resolution of symptoms. Complete radiographic reconstruction was observed in 66% of cases. Asymptomatic patients at 6 months returned to sports activity of similar intensity to that practiced previously in an average time of 7.9 months; while, patients who were symptomatic at 6 months returned in an average time of 16.5 months., Conclusion: This study provides evidence supporting the short-term efficacy of anterograde chondral drilling in stable lesion of OCD in children and adolescents after failed functional treatment., Level of Evidence: Level III (retrospective cohort study)., (© 2023. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Purpose: To implement a clinically applicable, predictive model for the lumbar Cobb angle below a selective thoracic fusion in adolescent idiopathic scoliosis., Methods: A series of 146 adolescents with Lenke 1 or 2 idiopathic scoliosis, surgically treated with posterior selective fusion, and minimum follow-up of 5 years (average 7) was analyzed. The cohort was divided in 2 groups: if lumbar Cobb angle at last follow-up was, respectively, ≥ or < 10°. A logistic regression-based prediction model (PredictMed) was implemented to identify variables associated with the group ≥ 10°. The guidelines of the TRIPOD statement were followed., Results: Mean Cobb angle of thoracic main curve was 56° preoperatively and 25° at last follow-up. Mean lumbar Cobb angle was 33° (20; 59) preoperatively and 11° (0; 35) at last follow-up. 53 patients were in group ≥ 10°. The 2 groups had similar demographics, flexibility of both main and lumbar curves, and magnitude of the preoperative main curve, p > 0.1. From univariate analysis, mean magnitude of preoperative lumbar curves (35° vs. 30°), mean correction of main curve (65% vs. 58%), mean ratio of main curve/distal curve (1.9 vs. 1.6) and distribution of lumbar modifiers were statistically different between groups (p < 0.05). PredictMed identified the following variables significantly associated with the group ≥ 10°: main curve % correction at last follow-up (p = 0.01) and distal curve angle (p = 0.04) with a prediction accuracy of 71%., Conclusion: The main modifiable factor influencing uninstrumented lumbar curve was the correction of main curve. The clinical model PredictMed showed an accuracy of 71% in prediction of lumbar Cobb angle ≥ 10° at last follow-up., Level of Evidence Iv: Longitudinal comparative study., (© 2021. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: The Petit-Morel method allows the treatment of developmental hip dysplasia in toddlers by combining gradual traction to achieve reduction followed by immobilisation during which pelvic osteotomy is performed. The objective of this study was to assess the radiographic and clinical outcomes in a retrospective cohort of patients., Hypothesis: The Petit-Morel method is associated with low rates of avascular necrosis and residual acetabular dysplasia at skeletal maturity, as well as with satisfactory medium-term clinical outcomes., Material and Methods: We conducted a single-centre retrospective study of 34 patients (35 hips) treated between 1997 and 2014. The radiological assessment criteria included an evaluation for avascular necrosis classified according to Kalamchi and MacEwan, the vertical centre edge (VCE) angle, femoral head sphericity according to Mose, and acetabular dysplasia at skeletal maturity according to Severin. Hip function was assessed by determining the Postel-Merle d'Aubigné (PMA) score., Results: Mean age at treatment was 19±4 months (range, 14-29). Mean follow-up was 11 years (range, 5-20). There were two failures including one case of recurrent dislocation requiring surgical reduction. Group II avascular necrosis occurred in 1 (3%) patient. Tönnis Grade IV dysplasia was significantly associated with resolving irregularity of the ossification centre, seen in 19 (54%) cases (p=0.002). In the 18 patients followed-up to skeletal maturity, with a mean follow-up of 15 years (range, 12-20 years), 17 hips were Severin Class I. The mean VCE angle was 29° (range, 15°-38°), and the head was spherical for 34 (98%) hips. The PMA score at last follow-up was excellent (17-18). The mean VCE angle was greater in all 5 patients who experienced pain during long walks (35° [range, 32°-37°]) than in the asymptomatic patients (28° [range, 15°-38°]) (p=0.009)., Discussion: The Petit-Morel method is a reliable treatment that provides good clinical and radiological outcomes. Overcorrection of the VCE angle was noted in the patients who experienced walking-related pain in adulthood., Level of Evidence: IV, retrospective observational cohort study., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Introduction: Treatment of ulnar impaction syndrome (UIS) is based on ulnocarpal decompression, which may be achieved by ulna shortening osteotomy. The aim is to restore zero or negative ulnar variance. Tolat et al. described 3 distal radioulnar joint (DRUJ) morphologic types: vertical, oblique and reverse. Joint type has been thought to influence the clinical result of shortening, especially in the reverse type., Hypothesis: DRUJ type does not influence clinical results in ulna shortening osteotomy., Material and Methods: Twenty-nine wrists were operated on in 27 patients: 13 female, 14 male; mean age at surgery, 43 years (range, 18-72 years). In 20 cases, UIS was idiopathic and in 7 post-traumatic. Mean preoperative ulnar variance was 3.6mm (range, 2-18mm). The osteotomy was fixed by screwed plate., Results: Twenty-five patients (27 wrists) were assessed at a mean 64 months (range, 18 months to 13 years). There were no cases of infection or hematoma. DRUJ was type 1 (vertical) in 6 cases (22%), type 2 (oblique) in 14 (52%) and type 3 (reverse) in 7 (26%). Mean postoperative pain score on VAS was 0.7/10 (range, 0-4); 9 wrists remained painful. Mean Quick-DASH was 16.9 (range, 0-48) and mean PRWE 21.9 (range, 16.9-59). Thirteen patients were very satisfied, 11 satisfied, 1 moderately satisfied, and 2 dissatisfied. Mean postoperative ulnar variance was -0.1mm (range, -4 to +8mm). Three wrists developed osteoarthritis, all following traumatic UIS. There were no significant correlations between DRUJ type and other clinical or radiological parameters., Discussion: Ulna shortening osteotomy has proven efficacy in UIS. The literature reports excellent or good results in 75% of cases. In the present study, 96% of patients considered themselves cured or improved by surgery, and none reported worsening. Ulna shortening osteotomy can be used in all 3 DRUJ types; DRUJ coronal morphology does not impact clinical result., Level of Evidence: IV-retrospective study., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Background: The primary objective of this study was to determine the time to and level of return to sports after anterior cruciate ligament (ACL) reconstruction in children and adolescents. The secondary objectives were to evaluate the risk of early ACL re-tear after return to sports and the risk of ACL tear in the contralateral knee., Hypothesis: The time to return to sports in young patients is considerably longer than in adults., Methods: A prospective multicentre study was conducted at 12 centres specialised in knee ligament surgery, in children and adolescents younger than 18 years, between 1 January 2015 and 31 October 2015. The patients were divided into a paediatric group with open physes and a skeletally mature group with closed physes. We recorded the time to return to sport, the type of sport resumed, and the occurrence of early re-tears on the same side. A poor outcome was defined as a re-tear or an objective IKDC score of C or D. A contralateral ACL tear was not considered a poor outcome., Results: Of 278 included patients, 100 had open physes and 178 closed physes. In the open physes group, return to running occurred after 10.4±4.7 months, return to pivoting/contact sport training after 13.1±3.9 months, and return to pivoting/contact sport competitions after 13.8±3.8 months. Of the 100 patients, 80% returned to the same sport and 63.5% to pivoting/contact sport competitions. Re-tears occurred in 9% of patients, after 11.8±4.1 months, and contralateral tears in 6% of patients, after 17.2±4.4 months. In all, 19.4% of patients had a poor outcome, including 10.4% with an IKDC score of C or D and 9% with re-tears. In the group with closed physes, return to running occurred after 8.8±5.1 months, return to pivoting/contact sport training after 11.7±4.7 months, and return to pivoting/contact sport competitions after 12.3±4.2 months. Of the 178 patients, 76.9% returned to the same sport and 55.6% to pivoting/contact sport competitions. The re-tear rate was only 2.8% and the contralateral tear rate 5%. In all, 14.7% of patients had poor outcome, including 11.9% with an IKDC score of C or D and 2.8% with re-tears. No risk factors for re-tears were identified; the quadruple-bundle semitendinosus technique showed a non-significant association with re-tears., Conclusion: In young children, the return to sport time after ACL reconstruction is considerably longer than 1 year and the return to competitions occurs later and is more difficult. The results of this study indicate that reservations are in order when informing the family about return to sports prospects after ACL reconstruction. The return to pivoting/contact sport competitions should not be allowed until 14 months after surgery in young skeletally immature patients, and the risk of re-injury is high within the first 2 years., Level of Evidence: IV, retrospective study., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Background: Outpatient surgery is now widely performed in adults but remains rarely used for paediatric orthopaedic procedures. As with adult surgery, both the arthroscopic equipment and anaesthesia techniques have improved over the last few years. Arthroscopy is particularly well advanced at the knee but can also be used at other joints (hip, ankle, elbow, shoulder). The primary objective of this study was to evaluate the feasibility of outpatient paediatric arthroscopy., Hypothesis: Arthroscopic surgery can be performed in children on an outpatient basis provided an appropriate care programme is applied., Materials and Methods: This single-centre retrospective study included 216 patients aged 3.8 to 18 years who underwent outpatient arthroscopy (knee, n=170; ankle, n=22; elbow, n=12; shoulder, n=6; and hip, n=6). The decision to perform the procedure on an outpatient basis was made with the patient during the surgeon visit then confirmed during the anaesthesiologist visit. The main outcome measure was failure of outpatient arthroscopy defined as a need for standard inpatient admission. The secondary outcome measures were pain or sleep disturbances on the day after the procedure (as assessed during a telephone call), a need to see a physician during the first week after the procedure, and patient satisfaction., Results: Of the 216 patients, 9 required overnight admission (4 because of vomiting, 4 because of pain, and 1 because of a malaise) and 2 patients were admitted elsewhere for postoperative pain then discharged within 24hours. Of the 160 patients who could be contacted on the day after the procedure, 141 (88%) said they had had a good night and 141 (88%) that they had little or no pain. Over 95% of patients were satisfied with their outpatient management., Discussion: As with adults, arthroscopic surgery is an ideal indication for outpatient care in paediatric patients. Outpatient arthroscopic surgery is already widely used at the knee and is also suitable for other joints in the paediatric population., Level of Evidence: IV, retrospective study., (Copyright © 2018. Published by Elsevier Masson SAS.)

Introduction: Proximal junctional kyphosis (PJK) is a frequent complication, up to 46%, in adolescent idiopathic scoliosis surgical treatment (AIS). Several risk factors have been evoked but remain controversial. The purpose of this study was to analyze the incidence of PJK in a multicenter cohort of AIS patient and to determine risk factor for PJK., Materials and Methods: Lenke I and II AIS patients operated between 2011 and 2015 (minimum of 2-years follow-up) were included. On fullspine X-rays, coronal and sagittal radiographic parameters were measured preoperatively, postoperatively and at final follow-up. Occurrence of radiological PJK corresponding to a 10° increase in the sagittal Cobb angle, measured between the upper instrumented vertebra (UIV) and UIV + 2, between postoperative and 2-years follow-up X-rays, was reported., Results: Among the 365 patients included, 15.6% (n = 57) developed a PJK and only 10 patients required a revision surgery. Preoperatively, PJK patients had significantly larger pelvic incidence (57° ± 13° vs. 51° ± 12°), larger lumbar lordosis (LL) (63° ± 12° vs. 57° ± 11°) and bigger C7 slope. Postoperatively (3 months), in the non-PJK group, thoracic kyphosis (TK) was increased and LL was not significantly different. However, postoperatively, in the PJK group, no significant change was observed in TK, whereas C7 slope decreased and LL significantly increased. There was also a postoperative change in inflection point which was located at a more proximal level in the PJK group. Between postoperative time and final follow-up, TK and LL significantly increased in the PJK group., Conclusion: PJK is a frequent complication in thoracic AIS, occurring 16%, but remains often asymptomatic (less than 3% of revisions in the entire cohort). An interesting finding is that patients with high pelvic incidence and consequently large LL and TK were more at risk of PJK. As demonstrated in ASD, one of the causes of PJK might be postoperative posterior imbalance that can be due to increased LL, insufficient TK or inflection point shift during surgery. These slides can be retrieved under Electronic Supplementary Material.

Study Design: Grand Round case report., Objective: We report a pancreatic fracture associated with Wirsung duct disruption, following a scoliosis surgery in a cerebral palsy adolescent. Spinal fusion surgery is the standard treatment for severe neuromuscular scoliosis. Many complications such as digestive ones account for its complexity. Postoperative acute pancreatitis is well described, although its pathophysiology remains unclear. To our knowledge, pancreatic fracture following scoliosis correction has never been described to date. Clinical presentation is not specific, and management is not consensual., Case Report: A 14-year-old adolescent had posterior spinal fusion for neuromuscular scoliosis due to cerebral palsy. During the postoperative course, she developed progressive nonspecific abdominal symptoms. The abdominal CT scan demonstrated a pancreatic fracture and a surgical exploration was decided as perforations of the bowel were highly suspected. Drains were placed around the pancreatic area as the retrogastric region was out of reach due to local inflammation. Conservative management led to the occurrence of a pseudocyst in the following weeks as the pancreatic leakage progressively dropped., Discussion: Two hypotheses have been proposed: direct iatrogenic trauma from lumbar pedicle screws and pancreatic rupture related to the correction of the spinal deformity. As the latter seems the most likely, spinal surgeons should be aware of this occurrence following severe scoliosis correction., Conclusion: Spinal fusion for severe neuromuscular scoliosis is a difficult procedure, with a high rate of complications. Among them, pancreatic fracture should be considered when abdominal pain persists in the postoperative period. Conservative management is advocated especially in case of a poor general condition.

Background: Port-a-cath (PAC) is an essential device in the management of the patients of chronic illness, but despite theirs benefits there are many complications either at the time of insertion or at time of removal. Our aim of this study is to evaluate the fracture rate of the catheter at removal time in comparison with catheter type either polyurethane or silicone., Methods: A retrospective monocentric study of all PACs which were removed at our university pediatric hospital between 1 January 2006 and 31 December 2016. Two groups were compared: polyurethane group and silicone group., Results: Total of 216 central lines were removed, the mean age at the time of extraction was 9.7±4.9years and the mean time for both catheter was 2.7±1.6years, fracture occurred in 11 catheter of the polyurethane group (n=119), with no fracture of silicone group (n=86), in the polyurethane group, the risk of catheter fracture is significantly related to the duration of the PAC in place., Conclusion: We found that the polyurethane-based catheters are more vulnerable for rupture and retained fragment in the blood vessels, especially if left in place for long time, for this reason we have switched to silicone-based catheter and all catheters should be remove within duration maximal of 2years., Type of Study: Prognosis study., Level of Evidence: Level II., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Case: Osteochondritis dissecans (OCD) rarely affects the humeral head. We describe a 14-year-old adolescent who, despite conservative treatment, had persistent pain in the left shoulder as well as limited function. Radiographs and a computed tomography (CT) arthrogram revealed an osteochondral defect of the humeral head. He was managed with an arthroscopic osteochondral autograft transfer from the knee, which provided a satisfactory outcome., Conclusion: Arthroscopic osteochondral autograft transfer is an effective option for the treatment of OCD of the humeral head.

Purpose: Despite their functional importance, the infraspinatus (ISP) and teres minor (TM) muscles have been little investigated. This study aimed to describe the macroscopic morphology, innervation, and inter-relations of the ISP and TM muscles., Methods: Forty fresh cadaver dissections and histologic analysis were performed. Three groups of specimens were distinguished according to the rotator cuff tendon status: (1) intact rotator cuff; (2) supraspinatus tendon tears with intact ISP tendon; and (3) both supraspinatus and ISP tendons torn. Muscle fiber organization and muscle and tendon length were recorded. ISP and TM innervation and fiber structure were studied., Results: ISP muscles were composed of three groups of fiber organized in two planes: two superficial groups, with mean pennation angles of, respectively, 27° ± 4° and 23° ± 3° with respect to the axis of the central tendon of the underlying group. TMs were thick fusiform muscles showing a parallel organization; 26 specimens (67 %) had aponeuroses isolating the TM, with a mean length of 5.2 ± 2.7 cm. Rotator cuff lesions were associated with relatively greater ISP tendon than muscle length. Innervation of the ISP muscle comprised 2-4 main branches from the suprascapular nerve and that of the TM 1 branch from the axillary nerve., Conclusion: ISP muscle body morphology derives from three groups of fibers in two planes. The TM has a parallel organization. Several nerve branches innervate the ISP muscle, whereas only one supplies the TM. The limits between the two muscles bodies consist of an aponeurotic fascia in two-thirds of cases.

Inter-organ communication is essential for plants to coordinate development and acclimate to mechanical environmental fluctuations. The aim of this study was to investigate long-distance signaling in trees. We compared on young poplars the short-term effects of local flame wounding and of local stem bending for two distal responses: (1) stem primary growth and (2) the expression of mechanoresponsive genes in stem apices. We developed a non-contact measurement method based on the analysis of apex images in order to measure the primary growth of poplars. The results showed a phased stem elongation with alternating nocturnal circumnutation phases and diurnal growth arrest phases in Populus tremula × alba clone INRA 717-1B4. We applied real-time polymerase chain reaction (RT-PCR) amplifications in order to evaluate the PtaZFP2, PtaTCH2, PtaTCH4, PtaACS6 and PtaJAZ5 expressions. The flame wounding inhibited primary growth and triggered remote molecular responses. Flame wounding induced significant changes in stem elongation phases, coupled with inhibition of circumnutation. However, the circadian rhythm of phases remained unaltered and the treated plants were always phased with control plants during the days following the stress. For bent plants, the stimulated region of the stem showed an increased PtaJAZ5 expression, suggesting the jasmonates may be involved in local responses to bending. No significant remote responses to bending were observed., (© 2013 Scandinavian Plant Physiology Society.)