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Background Temporary hemiepiphysiodesis (TH) using an eight-Plate implant is one of the most common surgeries used for the correction of coronal angular deformities around the knee in adolescents. However, few studies have focused on children aged less than 10 years treated with TH using an eight-Plate implant. The purpose of this study was to investigate the efficacy, correction velocity, and complications of TH with an eight-Plate implant as well as the occurrence of rebound and risk factors in this population. Methods This retrospective study included a total of 135 physes (101 knees) from 66 children (mean age of 4.69 years old, range from 1 to 10 years old) who underwent TH with an eight-Plate implant to correct coronal genu angular deformities in our hospital. Related clinical factors were recorded and analysed by multivariable linear and logistic regression models. Results The mean deformity correction period was 13.26 months, and the mean follow-up after eight-Plate removal was 12.71 months. In all, 94.06% (95/101 knees) of the genu angular deformities were completely corrected. Non-idiopathic genu angular deformity was found to be an independent risk factor for deformity correction failure (odds ratio (OR) = 2.47). The femoral correction velocity was significantly higher than the tibial correction velocity (1.28° vs. 0.83° per month, p Conclusions TH using an eight-Plate implant is an effective procedure for coronal genu angular deformities with a low incidence of complications and rebound in patients younger than 10 years old. For this population, TH using an eight-Plate should be considered as soon as the deformity stops responding to conservative treatments. The parents of children younger than 10 years of age with non-idiopathic deformities should be informed preoperatively that the deformity may be prone to correction failure or screw loosening after eight-Plate implantation.

The present study was to investigate the clinical features of foreign body (FB) residues in children's knee joints, surgical retrieval, and postoperative function of knee joints.This retrospective study included a total of 13 children (8 boys and 5 girls; the mean age is 6.69 years old, range from 2 to 16 years old) who underwent retrieval surgery of knee FBs in our hospital. Related clinical factors were recorded and analyzed to find the influence factors of surgical methods and FBs' location change.The FBs in 11 cases were removed completely by arthroscopy, two cases by open surgery changed from arthroscopy. Besides glass pieces (n = 4, 31%) and wooden splinter (n = 1, 7%), sewing needle fragments were the most common type of knee foreign body (n = 8, 62%). There were two patients with FBs whom open surgery changed from arthroscopy was performed. The FBs of patients with open surgery changed from arthroscopy were more likely to locate in the posterior compartment (p = 0.04), and had a higher interval between injury and surgery than that in patients with arthroscopy (p = 0.01). The location of FBs (all were needle fragments) had changed intra-operatively in three patients, whose mean weight was lower than patients with fixed FBs (p = 0.04). The FB (small glass piece) of one patient was flushed out of the joint during arthroscopy.Arthroscopic retrieval surgery was an effective procedure to remove the FBs of the children's knee joint. The earlier it is detected, the easier it is to be treated. The location change of FBs should be cautioned in arthroscopic surgery and they are more likely to migrate into the posterior compartment of the knee joint.

Background: The tibial tubercle–trochlear groove (TT-TG) distance was originally described for computed tomography (CT), but it has been measured on magnetic resonance imaging (MRI) in patients with patellar instability (PI). Whether the TT-TG measured on CT versus MRI can be considered equivalent in skeletally immature children remains unclear. Purpose: To investigate in skeletally immature patients (1) the effects of CT versus MRI imaging modality and cartilage versus bony landmarks on consistency of TT-TG measurement, (2) the difference between CT and MRI measurements of the TT-TG, and (3) the difference in TT-TG between patients with and without PI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We retrospectively identified 24 skeletally immature patients with PI and 24 patients with other knee disorders or injury but without PI. The bony and cartilaginous TT-TG distances on CT and MRI were measured by 2 researchers, and related clinical data were collected. The interrater, interperiod (bony vs cartilaginous), and intermethod (CT vs MRI) reliabilities of TT-TG measurement were assessed with intraclass correlation coefficients. Results: The 48 study patients (19 boys, 29 girls) had a mean age of 11.3 years (range, 7-14 years). TT-TG measurements had excellent interrater reliability and good or excellent interperiod reliability but fair or poor intermethod reliability. TT-TG distance was greater on CT versus MRI (mean difference, 4.07 mm; 95% CI, 2.6-5.5 mm), and cartilaginous distance was greater than bony distance (mean difference, 2.3 mm; 95% CI, 0.79-3.8 mm). The TT-TG measured on CT was found to increase with the femoral width. Patients in the PI group had increased TT-TG distance compared with those in the control group, regardless of landmarks or modality used ( P > .05 for all). Conclusion: For skeletally immature patients, the TT-TG distance could be evaluated on MRI, regardless of whether cartilage or bony landmarks were used. Its value could not be interchanged with CT according to our results; however, further research on this topic is needed.

Background: Evaluation of intra-articular osteochondral fractures in children with acute traumatic lateral patellar dislocation (LPD) is important for determining treatment options. Purpose: To (1) compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) for evaluating intra-articular osteochondral fractures; (2) compare the interpretation of CT and MRI images between radiologists and pediatric orthopaedic surgeons (POS); and (3) investigate any clinical factors influencing the accuracy of CT and MRI evaluations. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: We reviewed 35 knees in 35 patients (mean age, 12.2 ± 1.2 years; 12 boys and 23 girls) who were treated arthroscopically for acute traumatic LPD; 71% of the patients had patellar fractures, 54% had femoral fractures, and 60% had free osteochondral fracture fragments. All presurgical MRI and CT images were reviewed by POS who were blinded to both the reports of the radiologists and surgical records. We compared the accuracy of CT and MRI in diagnosing intra-articular osteochondral fractures against the arthroscopic findings and compared the interpretation of the images by the POS (MRI-O, CT-O) with those of the radiologists (MRI-R, CT-R). Results: There was no significant difference in diagnostic accuracy between CT and MRI for overall intra-articular osteochondral fractures by the POS or the radiologists; however, the CT-O images had a higher diagnostic specificity (84.2% vs 69.6%; P < .001) and sensitivity (88.1% vs 70.1%; P < .001) versus the MRI-R images. Regarding free fracture fragments, the CT-R images had a higher diagnostic accuracy than the MRI-R images (73.5% vs 47.1%; P = .026). When backed by clinical data, the MRI-O images had greater diagnostic accuracy (78.7% vs 60.3%; P = .001) and sensitivity (88.1% vs 30.7%; P = .021) but lower specificity compared with the MRI-R images, and the CT-O images had similar diagnostic accuracy but greater sensitivity than the CT-R images (70.1% vs 52.2%; P < .001). The diagnostic accuracy of MRI-O images was lower for children under 12 years versus children 12 years and over (67.5% vs 83.3%; P = .040). Conclusion: Compared with MRI, CT scans had better diagnostic performance in the evaluation of intra-articular osteochondral fractures in pediatric patients with acute traumatic LPD. Clinical data enhanced the diagnostic sensitivity of MRI and CT but decreased the specificity of MRI. MRI evaluations remain challenging for both POS and radiologists.

The rate of angular correction (ROAC) is very unpredictable and may be affected by various factors in the treatment of genu valgum and varum by means of guided growth. The purpose of this study was to assess the ROAC in cases from our institution and to identify risk factors associated with the occurrence of lower ROAC. We retrospectively reviewed the chart records of 68 patients undergoing guided growth with figure-eight plate for the correction of genu valgum and varum. Based on the data from these patients, the annual increment of physeal growth was calculated and compared with data from the Anderson chart. The associations between patient characteristics and ROAC were evaluated with the use of univariate logistic regression. The mean rate of femoral angular correction was 10.29 degrees/year, while the mean rate of tibial angular correction was 7.92 degrees/year. In a univariate logistic regression analysis, the variables associated with a higher risk of lower ROAC included non-idiopathic coronal deformity of the knee (odds ratio = 13.58, p Obesity and non-idiopathic coronal deformity of the knee are risk factors for lower ROAC. It is still uncertain whether severity of deformity, race, and operative procedure have a substantial effect on the rate of correction. Level III evidence.

In this study, a new outer-cycle flat-panel photobioreactor was designed for an anaerobic, photo-fermentation process by Rhodobacter sphaeroides ZX-5. In order to obtain the high hydrogen yield, photo-hydrogen production by fed-batch culture with on-line oxidation–reduction potential (ORP) feedback control was investigated. Meanwhile, the effects of feeding malic acid concentration and pH adjustment on the growth and hydrogen production of R . sphaeroides ZX-5 were studied. In the entire fed-batch culture, biomass (i.e., OD 660 ) rapidly increased up to 1.79 within 18 h, and then OD 660 value stayed constant within a range of 1.85–2.18 until the end of the photo-fermentation. The cumulative hydrogen volumes in each phase of fed-batch process were 2339, 1439, 1328, and 510 ml H 2 /l-culture, respectively. Throughout the entire repeated fed-batch photo-fermentation, the maximum substrate conversion efficiency of 73.03% was observed in the first fed-batch process, obviously higher than that obtained from batch culture process (59.81%). In addition, compared to the batch culture, a much higher maximum hydrogen production rate (102.33 ml H 2 /l h) was achieved during fed-batch culture. The results demonstrated that photo-hydrogen production using fed-batch operation based on ORP feedback control is a favorable choice of sustainable and feasible strategy to improve phototrophic hydrogen production efficiency.