Study On Relationship Between Accessory Navicular And Flatfoot Deformity

The main feature of flatfoot deformity is reduction or disappearing of the longitudinalarch of the foot, performance as the ankle pain,medial swelling,forefoot abduction, hindfootvalgus,seriously affect the patient’s life.The progression of this disease to a certain stagewill lead to the lower extremity pain,weakness,walking inconvenience and other clinicalsymptoms.Congenital malformations, inflammatory,degenerative joint disease, trauma,neuromuscular disease and posterior tibial tendon dysfunction can cause flatfoot deformity.The most common accessory navicular bone derive from the second scaphoid ossificationcenter，locate at the medial of scaphoid；According to the accessory navicular bone shapeand its relationship with the scaphoid,it is divided into3types.At present,the relationship ofaccessory navicular bone and flatfoot deformity is no clear conclusion。The author find that part of accessory navicular bone patients have flatfoot deformityin clinical work,therefore,design the subject to discuss the relationship of accessorynavicular and flatfoot deformity. Firstly, the author analyse the prevalence of accessorynavicular and flatfoot deformity in physical examination population，to understand therelationship of accessory navicular and flatfoot deformity. Secondly，by MRI and operation,the author may understand the relationship between accessory navicular bone and posteriortibial tendon；Finally，further through the analysis of the operation effect, the author willclarify that resection of the accessory navicular bone and posterior tibial tendonreconstruction can improve patients arch.The part1：Analysis of flatfoot deformity and accessory navicular in physicalexamination populationIn the city of Chongqing and the surrounding area, over20years of age in thispopulation, the author screen flatfoot deformity and accessory navicular bone to understandthe incidence and the relationship between them.1.1Material and method 1.1.1Case informationsFrom Mar.2012to Jun.2012,a total of2046people,924men,1122women,20~83years old, average age is48.5years old。1.1.2Inspection methodPreliminary investigation include age, height, weight, name, foot appearance etc.Review investigation include the ankle and foot examination and X examination.2.2Experimental resultThe prevalence rate of flatfoot deformity is about5.4%, a total of111people,38men,73women;Prevalence rate of flatfoot deformity in female is higher than in male; Theprevalence rate of accessory navicular bone is about5.4%, a total of220people,95men,125women; In40-50age group,the number of flatfoot deformity and accessory navicularbone is most. The prevalence rate of flatfoot deformity in physical examination populationincreases with age; Accessory navicular prevalence rate have no difference.34patients haveflatfoot deformity associated with accessory navicular bone, accounted for30.6%patientswith flatfoot deformity, accounted for15.5%patients with accessory navicular bone.2.3ConclusionWe find that prevalence rate of flatfoot deformity is about5.4%, prevalence rateincrease with age, prevalence rate of female is higher than male. The prevalence rate ofaccessory navicular bone is about10.75%, prevalence rate has no difference in genderand age. Flatfoot deformity associated with accessory navicular bone have34patients,accounted for1.7%of the patients in all physical examination population, accounted for30.6%patients with flatfoot deformity, accounted for15.5%patients with accessorynavicular bone. Statistical analysis showed that the accessory navicular bone is associatedwith foot deformity.The part2MRI maging Findings and Surgical findings of Painful AccessoryNavicular BoneRetrospective analysis, MRI and Surgical findings of painful II accessory navicularbone, we evaluate the relationship between them, and explore the change of posterior tibialtendon function.2.1Materials and methods2.1.1Case informations From Jan.2010to Jan.2012, type II accessory navicular bone,36patients,16men,20wem. Medial foot chronic pain and tenderness, The mean preoperative duration of about18months(5-28months).2.1.2Preoperative MRI, Intraoperative accessory navicular bone resection andreconstruction of posterior tibial tendon.2.1.3Content of MRI and operation recordsFrom analysis of MRI image,we evaluate changes of signal intensity in the accessorynavicular bones, synchondrosis and adjacent soft tissue on the T1-weighted images andfat-suppressed T2-weighted image (WI), The changes in the signal intensity were comparedto those of the adjacent fatty marrow; also evaluate the presence of synchondrosis wideningand PTT pathology, such as tenosyn-ovitis, tendinosis and tear.From analysis of operation records,we understand the relationship between theposterior tibial tendon and accessory navicular bone, Understand cartilage joint andcartilage injury between accessory navicular bone and navicular bone.2.2Experimental resultsAll MRI images show bone marrow edema, high signal accessory navicular bone andcartilage; cartilage adjacent to the joint nontendon and soft tissue of34patients can beobserved at high signal strong.12cases of posterior tibial tendon sheath fluid, MRI foundthat:8cases of tendon lesions.Intraoperative findings:8cases are found augmentation in cartilage joint, existingmobile accessory navicular bone; Part posterior tibial tendon of25cases stop in theaccessory navicular bone,the rest of the tendon fibers downward or upward around theaccessory navicular bone; Posterior tibial tendon of11cases completely stop at theaccessory navicular bone; All36cases patients have cartilage surface damage betweenaccessory navicular bone and navicular bone.2.3ConclusionThe MRI images of patients with type II pain accessory navicular bone mainly aresustained bone edema and cartilage degeneration;Posterior tibial tendon and the other softtissues both are high signal;Intraoperative findings: cartilaginous surface is rough, notsmooth, this show necrosis of bone, tendon inflammation and destruction of the accessorynavicular bone. Expression of MRI is not entirely consistent with Intraoperative findings,operation choice mainly depends on clinical manifestations;Operation purpose is to resectaccessory navicular bone, to remove inflammatory tissue,to relieve pain,to correct abnormalmechanical structural.The part3Analysis on effect of operation of flatfoot deformity with the accessorynavicular boneThrough analysis of clinical effect, further verify the influence that accessorynavicular bone to posterior tibial tendon function, analysis of simple accessory navicularbone resection of posterior tibial tendon reconstruction and analysis of accessorynavicular bone resection of posterior tibial tendon reconstruction combination ofcalcaneus ingression osteotomy.3.1Materials and methods3.1.1Case informationFrom Mar.2010to Dec.2012，34patients (37feet) have chronic pain, shoes difficult.Preoperative X and MRI show II accessory navicular bone.All with flatfoot deformity,calcaneal valgus of10patients (12feet).3.1.2In24cases (25feet) with accessory navicular bone resection and reconstructionof posterior tibial tendon,10patients (12feet) with accessory navicular bone resection ofposterior tibial tendon reconstruction combination of calcaneus ingression osteotomy.3.1.3Clinical assessmentIncluding general evaluation, function evaluation and imaging evaluation; Generalassessment includes symptoms, satisfaction, wound healing and postoperativecomplications;Functional assessment include AOFAS ankle foot score, VAS score;imagingevaluation include the arch height, calcaneus inclination angle(CI), talocalcaneal angle(TC),talar first metatarsal angle(TMT) on the lateral weight-bearing radiograph of foot, and thetalocalcaneal angle(TC), talar first metatarsal angle(TMT) on the AP view of theweight-bearing radiograph of foot, and the heel valgus alignment on axial radiographs ofthe hindfoot.3.2Experimental results24patients undergo accessory navicular bone resection of posterior tibial tendonreconstruction.The average AOFAS ankle-midfoot score improved from52.1preoperatively to86.2at the last follow-up; The average VAS from preoperative4.83to last1.03; the archheight from3.7±0.2to12.4±1.1mm, CI from10.4°±1.0°°to21.5°±1.8°, TC from47.3°±2.5°to32.3°±2.5°and TMT from17.6°±1.6°to6.8°±1.0°on the lateralweight-bearing view; TC from39.5°±2.3°to26.2°±2.0°and TMT from15.2°±1.7°to6.3°±1.0°on the AP weight-bearing view. There is significant difference （P<0.005）.10patients undergo accessory navicular bone resection of posterior tibialtendonreconstruction of calcaneus ingression osteotomy; The average AOFAS ankle-hindfootscore improve from48.3preoperatively to80.1at the last follow-up; The average VASimprove from5.03to0.84; the arch height from3.3±0.5to10.4±0.5mm, CI from12.4°±1.4°to23.2°±1.6°, TC from46.1°±2.7°to33.3°±1.3°and TMT from15.3°±1.9°to6.5°±1.4°on the lateral weight-bearing view; TC from40.9°±2.7°to24.5°±2.6°and TMTfrom15.4°±1.7°to6.7°±1.4°on the AP weight-bearing view. The heel valgus of all patientswas corrected on the axial view. There is significant difference （P<0.005）. There was noany complication, including infection, nerve injury,un-union, and so on.3.3ConclusionThe accessory navicular bone resection combined with posterior tibial tendonreconstruction and the medial displacement calcaneal osteotomy with reconstruction ofposterior tibial tendon on navicular is a good choice for the treatment of flatfoot relatedwith accessory navicular with excellent clinical outcomes, correction of deformity.