The Study Of Ultrastructural Of Gastrocnemius In Children With Idiopathic Clubfoot

BackgroundClubfoot is one of the most common foot deformities in children.The deformities usually affect the front foot,middle foot,back foot,ankle joint and calf.The deformities are adduction,varus,plantar flexion and high arch deformities.The incidence of the disease is 0.1-0.6%,mostly seen in males,with a ratio of about 3:1 between males and females,mostly seen on both sides,accounting for about 50%.According to the etiology,it is clinically divided into postural clubfoot,idiopathic clubfoot(ICF)and secondary clubfoot,including Tethered Cord Syndrome(TCS)secondary,Cerebral palsy,traumatic,etc.The majority of children treated in our department are secondary to Tethered Cord Syndrome(TCS).Whether it is idiopathic or secondary to TCS,the range of motion of the feet is poor and the deformity is severe.After the occurrence of clubfoot shape changes in the feet of the children,the deformity of the feet secondary to TCS will be progressively aggravated,seriously affecting the standing and walking of the children,and the recurrence rate is high.At present,many scholars have studied the etiology of this disease through different methods,but the cause of the clubfoot is still inconclusive.The differences are mainly at the genetic level and the bone and muscle changes in the feet and calves.Many scholars at home and abroad have found that the calf muscle group of children with clubfoot has different degrees of atrophy,among which the gastrocnemius atrophy is the most serious,but whether it participates in the occurrence and development of clubfoot remains to be further studied.ObjectiveWe can make it clear that the ultrastructure of gastrocnemius changes in Idiopathic Clubfoot by light microscopy,SEM and TEM in this study.The pathogenesis provides pathological data for the pathological diagnosis of idiopathic clubfoot,increases the understanding of the disease by clinicians and pathologists,provides theoretical support for the choice of surgical methods and reduces the recurrence rate.Method1.Material20 cases of idiopathic clubfoot and 20 cases of clubfoot secondary to TCS in our department of orthopedics from September 2016 to February 2018(ICF is 30 feet,TCS is 28 feet).The children were aged from 1 month to 5 years,with an average age of 1.3 years,including 13 males,7 females,10 unilateral and 10 bilateral.The children with TCS secondary horseshoe varus were 2.4 to 7 years old,with an average age of 5.2 years old.There were 11 males,9 females,12 unilateral and 8 bilateral cases.They were divided into two groups:the idiopathic clubfoot group(ICF group)and the clubfoot secondary to spinal cord syndrome(TCS group).Achilles tendon severance was performed in both groups.The distal muscle tissue of the gastrocnemius was taken during operation,and analyzed by optical microscopy,SEM and TEM.All muscle biopsy specimens were taken from the proximal 2 cm of the abdominal abdomen junction,and the strips were taken along the direction of the muscle fibers,and the extruded and pulled tissues were removed,and the size was about 3 mm × 3 mm × 6 mm.2.MethodsSpecimen fixation:The light microscope specimen was placed in a 10%neutral formaldehyde fixative immediately after removal,and then stored in a refrigerator at 4? for 24 h,embedded in paraffin,and made into a wax block,which was stored at room temperature for use;After the specimens were removed,they were immediately placed in a 2.5%,4%glutaraldehyde fixative solution,and then stored in a refrigerator at 40?.According to the needs of the experiment,light microscope,SEM and TEM specimens were prepared according to the requirements.The specimens were analyzed by microscope,SEM and TEM.In addition,retrospective analysis of the effect of Ponseti plaster cast and Achilles tendonectomy for children with idiopathic clubfoot is allowed.Results1.Results under light microscope:ICF:The myofibers were long columnar and loosely arranged,and the nuclei were oval and located below the myometrium.Many myofibrils can be seen in the sarcoplasm.The myofibrils were thin and relatively orderly,and there were light and dark horizontal stripes,and I band and A band can be seen.A large number of muscle satellite cells can be seen also.TCS:There were less muscle fibers,with irregular shape,and muscle fibers were relatively disorganized and more loose;There were few myofibrils,and the directions were not consistent.Some gastrocnemius muscles showed obvious fibrosis and fatty changes,muscle filaments were vacuolated,some nuclei were cord-like,and some muscle cells showed apoptosis and a large number of fibroblasts.The muscle satellite cells can be seen.The comparison between the two groups showed that the number of muscle satellite cells in the gastrecnemius muscle in the ICF group is more than that in the TCS group,and the number of muscle satellite cells in the gastrecnemius muscle was gradually decreasing with the aggravation of the foot symptoms.2.Results under scanning electron microscope:ICF:The muscle bundles were arranged and the shape was relatively good,part closely,and very few muscle bundles are loose and atrophic,some defected,distorted,partial fascicle edema,sarcomere mild disorder,muscle bundles gap increases slightly,collagen fiber section enlargement,as reticulation,the nuclear shape,oval nuclei.Some of the cells are seen as normal.TCS:Disordered arrangement of longitudinal section visible part muscle,muscle wire thickness is differ,part of the muscle defects,rupture,muscle bundle of edema,disordered arrangement of sarcomere,broadening,part of the defect,the gap between muscle increased significantly,collagen disorders,enlargement,the nuclear shape is irregular,some is oval shape,muscle wire tetanic contraction performance;In the transverse section,the nucleus was exposed,and the interfascicular collagen fibers were obviously disturbed and thickened,while some muscle fibers were absent.3.Results under transmission electron microscope:ICF:The arrangement of myofilaments and sarcomere was mildly disordered,the z-line was slightly widened,and the h-band was slightly shortened.The nuclear morphology was not regular,the fibers were fine and arranged loosely.Mitochondria and glycogen are slightly reduced,mitochondrial part of sputum is fused with a small number of membranes,ambiguous,disordered sacral arrangement,partial sputum rupture and loss;mitochondria enlargement,partial vacuolization,and some sarcoplasmic reticulum was slightly expanded,cell volume increased,and abundant cytoplasm.A large and obvious nucleolus can be seen.At the end of the nucleus,the basal submucosal matrix is reduced,and some deformed mitochondria are visible.TCS:The arrangement of muscle fibers was disordered,and fracture and large area deficiency were observed.The myofibrils were disorganized,and more myofibrils dissolved and disappeared.The myofibril structure was unclear,the myofibril space increased,and the number of myofibrils decreased.Myofilament swelling,loss of sarcoplasm,tonic contraction of myofilament,z-line widening,h-band shortening,z-line and h-band misalignment,incomplete and dissolution;Most of the cristae of mitochondria and part of the membrane fuse,blurred,there are many cristae fracture,missing phenomenon;More mitochondrial atrophy,rupture and reduction were observed,and mitochondrial vacuolation was.severe.There was a high degree of edema between the muscle fiber bundles,and the number of mitochondria and glycogen in the interstitium between the muscle fiber bundles decreased.In severe cases,the cytoplasm of muscle fibers was degenerated and necrotic,the cell membrane disappeared,and only the bare nucleus remained.ConclusionThis study found that children with ICF gastrocnemius muscle ultrastructure can be seen:1.The arrangement of muscle fibers and sarcomere is disordered,even broken,and the muscle fibers are progressively atrophied;The number of mitochondria is reduced and the structure is destroyed.The endoplasmic reticulum expands to different extents;The nuclear volume of the nucleus increases to a certain extent,and even nuclear pyknosis and necrosis occur.2.The number of satellites of the gastrocnemius muscle of the ICF is more than that of the secondary clubfoot.and the proliferation of muscle satellite cells is relatively high.The change is lighter and the deformity of the feet is milder.The conclusion is that the pathological changes of idiopathic clubfoot are lighter than the secondary clubfoot and the recurrence rate is low.