Anatomy Study Of Interior Extensor Retinacular And Lateral Ankle Ligament

Objective:The morphologies and relationships with the surrounding osseous marks of the interior extensor retinacular band and the lateral ankle ligament were observed,so as to provide the anatomical basis for the strengthened suture and anatomical reconstruction of the ligament.Methods:1.Twenty-three ankle cadavers provided by the Anatomy Department of Qingdao University were selected,the morphologies of the lateral band(or Stem ligaments)of the interior extensor retinacular(IER)were observed and weather have Oblique Superolateral Band(OSLB).And related histological test was done.The nearest distance between Stem ligament of IER and anterior fibular periosteum(AFP)was measured and recorded,then Stem was tried to suture to AFP.2.The anterior talofibular ligament(ATFL)and calcanofibular ligament(CFL)were observed and measured in 22 ankle cadavers used in part one.(excluding 1 case because of poor quality of ligament).(1)The morphology of ATFL and CFL,including bundle,ligament length,body width,if the ligament is multiple bundles,then measure the length and width of each bundle respectively;(2)The Angle between CFL and the long axis of the fibula;(3)The distance between the center of the fibular insertion of ATFL as well as CFL and the tip of the lateral malleolus,the anterior fibular tubercle and the obscure tubercle were measured;(4)Distance between ATFL center of talus insertion and lateral talus cervical point;(5)The vertical distance between CFL center of calcaneal insertion and calcaneal tubercle at horizontal plane and sagittal plane,each group of data was measured twice to take the average value,and statistical analysis was conducted.Results:1.Twelve cadaveric ankles can be identified oblique superolateral band(OSLB)that has tough texture upward the lateral IER connecting with SL confirmed to oblique superolateral band(OSLB)reported in previous studies.The inner and outer membrane of OSLB respectively connecting with inner and outer membrane of Stem,and could be easily fixed on AFP.The average value of distance between Stem and AFP was 11.60 mm,and the maximum and the minimum were respectively 19.04 mm and 6.53 mm,The P>0.05(P=0.2)in single sample K-S test,the distribution of distance confirmed to normality.None of SL in the study had ability to suture to AFP.In histology,the dense and thick hyaline collagen fibers are arranged in parallel in Stem,fibrocytes are slender and nuclei are hyperchromatic,there is a small amount of loose connective tissue in the inner layer,containing small blood vessels;In OSLB,it is mainly composed of loose hyaluronic collagen fibers,with a small amount of adipose connective tissue scattered between them.2.Among twenty-two ankle cadavers,eighteen were double ATFL and four were single ATFL.Among double-bundle ATFL,the superior bundle were 16.40±2.60 mm in length and5.50±1.13 mm in width,the interior were about 12.50±2.52 mm in length and 4.20±1.44 mm in width.The single bundle ATFL were 14.10±4.03 mm long and 8.09±1.86 mm wide.All CFL were single bundle,three cases along with lateral talocalcaneal ligament(LTCL),CFL were 23.31±2.23 mm in length,8.09±1.86 mm in width,and 137.13±7.76° in Angle to the long axis of the fibula.There is no significant correlation between the length multiply by width of feet and length as well as width of the superior and single bundle of ATFL or CFL.Among eighteen double-bundle ankles,fibular footprints of superior ATFL located on obscure tubercle in eleven cases,only one case located on obscure tubercle,rest 6 cases located on middle between two bundles.All 4 cases single-bundle located on obscure tubercle.The distance from upper and single band footprint to tip of the fibula obscure tubercle,and anterior tubercle of the fibula were 16.65±2.65 mm,4.03±1.38mm(7cases,except single bundle)and 17.25±1.78 mm.The distance from the fibula insertion of the lower band ATFL to the tip of the fibula,obscure tubercle and anterior tubercle of the fibula was 12.71±2.57 mm,4.77±1.69mm(16 cases),and 22.39±1.70 mm,respectively.The distance from the fibula insertion of the lower band ATFL to former bony markers was 8.86±1.45 mm,9.81±2.61 mm,25.67±2.62 mm.The distance between talus footprint and the lateral talus cervical point was 10.86±1.67 mm,interior bundle was18.08±1.10 mm.The vertical distance between CFL calcaneal insertion and the coronal plane at calcaneal tubercle level was 22.98±3.30 mm,The vertical distance between CFL calcaneal insertion and the horizontal plane at calcaneal tubercle level was 6.88±1.62 mm.Conclusion:1.The IER lateral bundle has anatomic variability,OSLB of IER and Stem has distinct different histological structure as well as could be used in Brostrom-Gould.Stem of IER has poor elasticity,and it should be used cautiously in the Gould operation.2.ATFL has anatomic variability and we can target to superior ATFL in reconstruction surgery.CFL are all single bundle,and different morphology of LTCL make CFL show different morphology.The length and width of ATFL or CFL are influenced by multifarious,There was no significant correlation with foot size.Calcaneal tubercle,lateral talus cervical point,obscure tubercle,tip of the fibula and anterior tubercle all play important roles in positioning lateral ankle ligament insertion.