Objective To observe prenatal ultrasonic manifestations of fetal rhomboencephalosynapsis(RES).Methods Data of 15 singletons with RES were retrospectively analyzed,and the prenatal intracranial and extracranial ultrasonic manifestations were observed.Results All 15 fetuses were found with transverse cerebellar diameter lower than the 3rd percentile of normal value in the same gestational week and bilateral cerebellar hemisphere fusion(15/15,100％).Cerebellar vermis completely loss was observed in 14 fetuses(14/15,93.33％),while partially loss was noticed in 1 fetus(1/15,6.67％).Invisible of the fourth cerebral ventricle was detected in 4 fetuses(4/15,26.67％),while the fourth cerebral ventricular index(4Vi)＜1 was found in 11 fetuses(11/15,73.33％).No"split line"sign between vermis and cerebellar hemisphere was detected.A total of 14(14/15,93.33％)were found with combining intracranial or extracranial malformations,including 13(13/14,92.86％)with other intracranial malformations,10(10/14,71.43％)with extracranial malformations,whereas 1(1/15,6.67％)fetus had no other malformation.Conclusion Prenatal ultrasonic manifestations of fetal RES mainly included small cerebellum transverse diameter,complete or partial loss of vermis,invisible or dysplasia of the fourth cerebral ventricle,fusion of bilateral cerebellar hemispheres,as well as combining with other intracranial and extracranial malformations.

Objective To study the effect of Ilizarov technique on thumb shortening and bone defect after trauma.Methods The clinical data of 20 patients with thumb shortening or bone defect treated by Ilizarov technique from April 2010 to January 2018 were retrospectively analyzed.There were 19 males and 1 female including 15 left fingers and 5 right fingers.The age ranged from 20 to 56 years,with an average of 33.1 years.The osteotomy plane included 9 cases at distal part of the metacarpal,6 cases proximal phalanx base,1 case interphalangeal joint and 1 case distal part of proximal phalanx.Two cases were osteomyelitis after proximal and distal phalanges trauma,which resulted in interphalangeal joint defects after lesion clearance,and the length of the joint defect was 0.5 cm and 0.7 cm respectively.One case was emergency finger shortening fusion,which resulted in metacarpophalangeal joint defect due to nonunion of fusion site,and the length of the joint defect was 0.5 cm.Causes of injury included mechanical strangulation (12 cases),crush injury (6 cases) and traffic injury (2 cases).Semi-ring external fixator was used to extend the extension.There were 15 cases of metacarpal bone osteotomy and 5 cases of proximal phalanx osteotomy,prolonged from the 5th day after surgery.The osteotomy was prolonged by 0.5 mm every day,once every 6 hours.Results The follow-up time ranged from 184 to 446 days with an average of 244.6 days.The average extension period was 62.2 days (26-118 days),and the average extension length was 3.1 cm (1.3-5.9 cm).The healing index was 43.7-84.1 d/cm and the average healing index was 64.8 d/cm.The external fixed extender was used for 114-376 days with an average of 206.3 days.The distraction index was 20.1 c/cm (range,19.5-21.4 d/cm) and the maturity index was 46.5 d/cm (range,39.4-110.1 d/cm) and the external fixation index was 66.5 d/cm (range,60-130.8 d/cm).The finger pointing function and sensory function of thumb were restored after operation.According to the trial criteria of thumb and finger reconstruction function evaluation in the upper limb part evaluation criteria of Hand Surgery Society of Chinese Medical Association,11 cases were excellent,9 cases good,and the excellent and good rate was 100％(20/20).The two-point discrimination was 4-9 mm.The patients were satisfied with the function and appearance.Conclusion Ilizarov technique is a good method to treat thumb shortening and bone defect after trauma.