BACKGROUND:During autologous tendon grafting, the ultimate tensile strength used for suturing the end of the ligament is important for successful surgery. Improving suturing strength and increasing the number of stitches is a good choice for increasing the fixed intensity. But excess amount of stitches can produce too many thread residues, thereby affecting tendon healing.
OBJECTIVE:To investigate the essential number of suturing pins for the anterior cruciate ligament revascularization in ligament end suture fixation to reduce suturing thread exposure.
METHODS:(1) In vitro biomechanics test:12 patel ar ligament specimens were divided into two groups:the specimens were sutured with 5 or 3 stitches using Krackow suture method. The suturing thread was J&J tendon suture thread. The strength of tensile was compared between the two groups by Tensile mechanical test was conducted to compare the strength of tensile between the two groups and to explore the optimal number of stitches and suturing method. (2) Clinical application:According to the results of in vitro experiments, modified Krackow suture method was used clinical y for arthroscopic anterior cruciate ligament reconstruction in 125 cases, including 62 cases receiving 3-stitch suture, and 63 cases undergoing 5-stitch suture.
RESULTS AND CONCLUSION:The fixed strength of tensile at suture sites was over 100 N for 3-stitch double-lock suture and 110 N for 5-stitch double-lock suture. There was no significant difference in the fixed strength between the two groups, but their strength values were both over the breaking strength of suturing materials. Moreover, the fixed strength could not be reduced by suturing throughout the ligament at the first stitch. Al the 125 cases were fol owed for 6.4 months averagely, and both 3-stitch and 5-stitch suture methods achieved good outcomes. The satisfaction rate was up to 99%, and no suture breakage or loosing occurred at early and late stages. These findings suggest that, using 3-stitch double-lock suture method, a satisfactory fixed strength can be achieved with reduced thread exposure. The suturing thread can run through the ligament at the first stitch, which can reduce thread exposure but not reduce the fixed strength.

BACKGROUND: Anterior cruciate ligament injury accompanied by unstable rotation is a hotspot in sports medicine. Further understanding of the anatomy and biomechanics of the anterolateral ligament can play a guiding significance for the recovery of knee joint rotational stability.
OBJECTIVE:To systematicaly review current literature on the anterolateral ligament of the knee and to understand the incidence, anatomy, morphology and histology of the anterolateral ligament as wel as mechanism of anterolateral ligament injury.
METHODS: The first author searched the PubMed, Medline, CNKI, Wanfang, VIP databases for articles specificaly addressing the anterolateral ligament. Data extraction related to the incidence, anatomy, morphometry, biomechanics, and histology of the anterolateral ligament and its relation to the “Segond” fracture was performed. The retrieve time ranged from 1878 to 2015. Totaly 362 literatures were retrieved, including 342 articles in English and 20 in Chinese. According to inclusive and exclusive criteria, 42 articles were included in result analysis.
RESULTS AND CONCLUSION:The occurrence rate of the anterolateral ligament ranges from 83% to 100%, and this range occurs because of smal discrepancies in the definition of the bony insertions of the anterolateral ligament. The anterolateral ligament originates anterior and distal to the femoral attachment of the lateral colateral ligament. It spans the joint in an oblique fashion and inserts between the fibular head and Gerdy tubercle of the tibia. Exact anatomic and morphometric descriptions vary in the literature, and there are discrepancies regarding the anterolateral ligament attachment to the capsule and lateral meniscus. The anterolaterial ligament is a contributor to the stability of tibial internal rotation, and histologicaly, it exhibits paralel, crimped fibers consistent with a ligamentous microstructure. The footprint of the anterolateral ligament has been shown to be at the exact location of the Segond fracture. The anterolateral ligament is a distinct ligamentous structure at the anterolateral plane of the knee, and it is likely involved in the control of excessive tibial internal rotation that can cause the Segond fracture.

ObjectiveTo investigate the correlation of MRI features and phenotypes and genetic mutations in Pelizaeus-Merzbacher disease.Methods Sixteen boys with clinical diagnosis of PelizaeusMerzbacher disease (PMD) were included in this study.Their ages ranged from 22 months to 9 years.They were examined by pediatric neurologists,and clinical classification was made according to the symptoms and physical signs.An experienced radiologist reviewed the cranial MRI images and analyzed the brain involvement,including pallidus globus,pyramidal tract,corpus callosum,cerebellar white matter,semiovale centrum,brain atrophy and ‘ tigroid sign’.ResultsThere were 8 patients with classic form,7 patients with transitional form and one patient with connatal form.They all showed diffuse delayed myelination in the white matter,with involvement of pallidus globus in 13 cases,pyramidal tract in 7 cases,corpus callosum in 11 cases,cerebellar white matter in 7 cases,semiovale centrum in 12 cases.Cerebral atrophy was found in 5 patients and eerebellar atrophy was found in one patient.Five cases depicted ' tigroid sign'.In patients with PLP1 gene point mutation,pyramidal tract and cerebellar white matter involvement showed a high incidence.Cerebellar white matter lesions were relatively frequent in children with transitional form and connatal form.In contrast,‘ tigroid sign' was often related to classic form,which indicated a better myelination and outcome.ConclusionPMD patients show distinct imaging features in their brains,which may be correlated with the phenotype and genetic mutation.

Objective To describe the MRI features of vanishing white matter disease (VWM).Methods Ten patients diagnosed as VWM between 2008-2013 were enrolled,with the mean age of(40 ±23)months.The clinical materials and MR images of them were reviewed retrospectively.The findings of MRI were analyzed by two experienced neuroradiologists in this study,including the location (cerebrum,cerebellum,brainstem,corpus callosum and internal/external capsule),size and signal intensity of the lesions,as well as the presence of cystic degeneration,cerebrum atrophy and the abnormal signal of the basal nuclei.Results MRI of brain typically showed extensive abnormal signal in the cerebral central white matter (10/10) and the focal lesion in subcortical white matter (9/10).The involvement of U-fibers was present in 7 cases.Cystic degeneration of the affected white matter was found in 7 cases.Abnormal signal also appeared in the white matter of posterior limb of the internal capsule (8/10),the external capsule (7/10),the inner rim (the callosal-septal interface) of the corpus callosum (8/10).The lesions of the thalamus and globus pallidus were detected in 2 cases.The white matter of the brainstem and cerebellum were involved in 6 and 7 cases respectively.Conclusion VWM typically shows a diffuse and symmetrical abnormal signal in the cerebral white matter with cystic degeneration on MRI,which is usually diagnostic.

Objective To observe the clinic efficacy of open transforaminal lumbar interbody fusion (TLIF) compared with minimally invasive operation in treating lumbar spinal stenosis and instability among obese and non‐obese patients .Methods A ret‐rospective analysis was performed in these cases of mono‐segmental lumbar spinal stenosis and instability between January 2011 and January 2013 .Perioperative index ,clinical efficacy ,and imaging results were observed and compared between different groups .Re‐sults Thirty‐four obese cases and 105 non‐obese cases were divided into two groups ,including conventional posterior open TLIF and minimally invasive TLIF operation ,to compare the results .Perioperative indexes of obese patients were more than non‐obese patients undergone open TLIF operation way and there was significant difference(P<0 .01);while by minimally invasiveTLIF oper‐ation way ,comparing the results of the surgical blood loss and incision size between obese and non‐obese group ,there was signifi‐cant difference(P<0 .05) .However ,there was not significant difference in the operative time between two groups(P>0 .05) .No cases of slippage or breakage of implants were found among all these patients after 6 months of follow up .Postoperative VAS and ODI among these four groups were better than before(P<0 .01) .Undergoing open postoperative VAS in obese group and in non‐obese group ,there was significant difference(P< 0 .05);undergoing minimally invasive postoperative ODI in obese group and in non‐obese group ,there was significant difference(P< 0 .05) .But ,undergoing open postoperative ODI in obese group and in non‐obese group ,there was not significant difference(P>0 .05);undergoing minimally invasive postoperative VAS in obese group and in non‐obese group ,there was not significant difference(P>0 .05) .Conclusion Therefore ,obese may be risk factor in treating lumbar spinal stenosis and instability .

Objective To explore the medial open wedge high tibial osteotomy (OWHTO) combined with arthroscopic condyle plasty with clinical flexion deformity in patients with osteoarthritis of knee varus.Methods From January 2014 to July 2015,11 cases (11 knees) of varus knee joint flexion deformity were applied the procedure of OWHTO combined with arthroscopic condyle plasty,including 4 male and 7 female;the average age was 52.1 years old (ranged from 48 to 58 years).OWHTO could adjust the line of force of the lower limbs in coronal plane (the connection line between femoral head center point and the center point of ankle joint) through lateral tibial plateau 62.5％ position,and implant allogeneic bone to support posterior inclination angle,underwent arthroscopic condyle plasty to improve flexion deformity at the same time.Results 11 patients in this group were all followed up,and the follow-up time was 1-2.5 years,average 1.5 years.No case of fracture nonunion or delayed healing was found.Imaging data was measured to evaluate the mechanical axis of lower extremity by the relative position of tibial plateau,femoral tibial angle,femoral notch width index,tibial plateau posterior angle before operation and one year after the operation.The relative position of the mechanical axis of the lower limb through the tibial plateau was 17.4％ ± 4.9％ preoperatively,and 58.9％ ± 3.1％ after operation,femoral tibial angle changed from 181.6°± 1.2° to 170.3°± 1.3°,tibial plateau posterior inclination angle:preoperative 7.7°±2.2°,postoperative 7.9°±1.9°,femoral notch width index was increased from 0.221±0.007 to 0.272±0.009 after operation,flexion deformity angle of preoperative was 11.1 °± 3.1 °,and 1.4°± 1.5° one years after operation,VAS score was (6.5 ± 1.1)points before surgery,and (2.5±0.8) points of postoperative,Lysh(o)lm score was (50.72±6.57) points before operation,and (75.72±7.41) points one year after operation,and the differences were all statistically significant.Conclusion 0WHT0 combined with arthroscopic condyle plasty can significantly improve the lower limb line and flexion deformity,and also maintain the posterior inclination angle of tibial plateau,and can get a good short-term efficacy.

Objective To estimate prenatal diagnoses strategy with abnormal results of non-invasive prenatal testing (NIPT) based on a case of mosaic for trisomy 22.Methods The pregnanct woman was recruited from Department of Prenatal Diagnosis Center of Xinhua Hospital.Ultrasound scans suggested fetal nuchal translucency was 3.5 mm.Peripheral venous blood was drawn from the pregnant woman for NIPT at 12+2 weeks gestation.For further prenatal diagnosis, amniocentesis was conducted at 16+2 weeks gestation, and karyotype analysis combination with chromosome microarray analysis (CMA) was executed to analysis amniocytes.Results NIPT results suggested that chromosome 21, 18 and 13 were normal and supplementary reports suggested that chromosome 22 were slightly above the normal range.Karyotype analyzed 35 cultured cells.Each of them revealed a normal female karyotype.However, CMA results suggested that chromosome 22 gain mosaic and its copy number was 2.26.The fetus was diagnosed as high possibility of mosaic for trisomy 22.Conclusions Combined with the NIPT results, which was slightly gain mosaic of chromosome 22, a prenatal diagnosis strategy were proposed.When NIPT results suggest chromosomal abnormities, karyotype analysis combination with CMA to diagnose were recommended.

Objective To investigate the clinical efficacy of arthroscopy with anchor treatment on acute patellar dislo?cation. Methods Retrospective analysis of patient with acute patellar dislocation cases who visited our hospital from March 2010 to June 2013 and were followed up for 10 months or more after being discharged. Patients all underwent physical exami?nation and imaging examination before operations. All operations were performed under arthroscopy. Joint hematoma were first drained, then articular cartilage injury were explored and repaired. Corresponding relationship between patella and femo?ral condyle were observed. After that, lateral retinaculum was released and medial patellofemoral ligament was repaired by suture anchors. Finally patellar reduction and its corresponding relationship with femur were observed after operation. Re?sults Medial patella cartilage injury and bone contusion of femoral condyle were all observed under arthroscopy. Medial patellofemoral ligament damage and tensed lateral patellar retinaculum were combined. By the time of follow-up at 10~18 months later, no dislocation was found and fear test are all positive. No recurrence of patellar dislocation was observed. Compared the conditions before operation and the last follow-up, Lysholm score(91.38±1.65 vs 60.04±3.93), Kujala score (90.62±2.08 vs 55.27±3.00),patellar camber angle(11.96°±1.43° vs 25.15°±2.13°)were all imporved(P<0.01). Conclu?sion Arthroscopy with suture anchors present good clinical effect in the treatment of acute patellar dislocation, which in?cludes alleviating keen pain, stabilizing joint instability and restoring knee stretching. It also present with less recurrence of patellar dislocation.

Objective To summarize the phenotypic features of an unrecognized leukoencephalopathy in infants sharing same clinical features,and to better understand the disease and provide new evidence for identification of new leukoencephalopathy. Methods Clinical and follow-up data of 13 patients with unrecognized infantile leukoen-cephalopathy were collected from Peking University First Hospital from January, 2006 to December, 2014. Results (1) There were 7 male and 6 female. The average age of onset was 11 months (4-25 months). Thirty-eight percent (5/13 cases) of patients had incentives before the onset;all of the cases had acute onset and rapid motor function regression. Fifteen percent (2/13 cases) of the patients suffered from seizures in the course of the disease. Patients′condition became stable,and cognition and motor function improved gradually 1 month after onset. No patient died till the last follow-up. (2) Imaging features:magnetic resonance imaging (MRI) of the patients was characterized by im-plicating deep white matter,presenting T1 hypointense,T2 and fluid attenuated inversion recovery ( FLAIR) hyperin-tense in the periventricular area. All of MRI showed massive and symmetric lesions with heterogeneous signal and cystic degeneration. DWI showed patch or massive hyperintense in some of the lesions. The follow-up MRI showed the original lesions decreased in 88% ( 8/9 cases ) of patients, and white matters atrophied in 55% ( 5/9 cases ) of patients;the cystic degeneration still existed and even expanded;DWI showed regional linear or spot hyperintense in 88% (8/9 cases) of patients,which was smaller than before,and distributed around the original lesions. Conclusions The patients with leukoencephalopathy caused by unknown pathogenic gene were much likely to be mitochondrial leukoencephalopathy. This study provided evidence for further exploration of new pathogenic genes causing leu-koence-phalopathy.

Objective: To study the specific correlation between physical activity intensities and body compositions of adolescents and to provide guidance for the improvement of various body compositions of Chinese adolescents. Methods: From September to December 2019, body composition measurement based on bioelectrical impedance analyzer and the physical activity measurement based on accelerometers were performed among 971 adolescents from 8 high schools, such as Tsinghua Middle School in Beijing, by random number coding sampling. Statistical analysis was conducted by using independent sample t test, Pearson correlation coefficient method and multiple linear regression method. Results: Sedentary behavior(SB) of the junior and senior high school boys was significantly lower than that of girls, while the VPA(vigorous physical activity) and moderate vigorous physical activity(MVPA) were significantly higher than those of boys ( t =-1.98, -8.09; 5.20, 4.52; 3.53, 4.03, P <0.05). light physical activity(LPA) and moderate physical activity(MPA) of boys were significantly higher than those of girls in the senior high schools ( t =3.67, 5.63, P <0.01). Lean mass(LM) of the junior school boys was correlated to their MVPA( β =0.302), bone mineral content(BMC) was quantitively related to SB( β =-0.001), MVPA( β =0.002), and fat mass(FM) was related to SB( β =0.050), and MVPA( β =-0.323) ( P <0.05). LM of junior school girls was quantitively correlated to LPA ( β =0.080) and MVPA( β =0.613). And there was also correlation among BMC ,SB( β =-0.004) and MVPA( β =0.008) between FM and MVPA( β =-0.237) ( P <0.05) . There was a correlation between total body LM and MVPA ( β =0.393), total body BMC and SB ( β =-0.001), MVPA ( β =0.002), and total body FM and MVPA ( β =-0.393) in senior high school boys( P <0.05). There was a correlation between senior high school girls’ total body LM and LPA ( β =0.063), MVPA ( β =0.601), total body FM and SB ( β =0.029), and MVPA ( B =-0.529)( P <0.05). Conclusion There are gender differences and correlations between adolescent physical activity intensity and body composition. It is recommended that relevant departments provide personalized physical activity dose guidance for adolescents to improve their physical fitness.