The MRI Findings And Clinical Significance Of The Lumbar Endpalte Osteochondritis

Objective: Lumbar endplate osteochondritis is a new kind of degenerative discaldisease found on MRI in recent years. There are some relative references abroad already,while little reports about this entity were found in our country, especially cohort study. Our study is to explore initially the incidence of lumbar endplate osteochondritis in our country through cohort study of MRI findings ,clinical and pathological comparing analysis;to analyse the pathological foundation of MRI findings by comparing with pathological outcomes;and to evaluate the MRI findings ,classification and its clinical significance.Materials and Methods: A consecutive 1 926 lumbar MRI cases were analysed.Among these cases 1 681 lumbar degenerative diseases accompanied with degenerative discal disease were screened in our study, from which we choose 432 cases presenting with endplate osteochondritis at first presentation to evaluate . Eight cases were verified after surgery, the others have typical findings, and were verified through follow-up in most cases. All cases were accomplished with lumbar surface coils. The sequences include Sigittal SE T1WI, Sagittal and axial FSE T₂WI. Calculate the cases and the numbers of invovled discs that has endplate osteochondritis, analyse the type, period , relative MR findings and pathological results. The clinical relation between MRI findings of endplate osteochondritis and low back pain was statistically analysed.Results : Of the 432 cases presenting with endplate osteochondritis at firstpresentation , 341 cases with 430 involved discs had endplate osteochondritis accompanied with disc hemiation or ligment hypertrophy;91 cases with 109 involved discs had only endplate osteochondritis, which were subdivided on MRI into 4 types:bone marrow type, disc type, central nucleus pulposus hemiation type (i.e. Schmorl's node) , and mixing type. The bone marrow type was divided into active period or Modic 1 type, which is hypointensive on TiWI and hyperintensive on T2WI;stabilization period or Modic 2 type, which is both hyperintensive on T1WI/T2WI;healing period or Modic 3 type, which is both hypointensive on T1WI/T2WI. Disc type represents with transverse linear or bandlike enhancement along the edge of the disc on CE TiWI or linear or bandlike hyperintensive zone within the severe degenerative disc on T2WI. Central nucleus pulposus hemiation type represents with the nodular signal resulted from hemiation of nucleus pulposus into the bone through the ruptured or weak endplate. During acute period, there are the same changes as the Modicl in bone marrow type around the Schmorl's node,eg,hypointensive on TiWI and hyperintensive on T2WI. Of the 91 cases with only endplate osteochondritis at first presentation , 60 have only bone marrow type ,13 have only Schmori's node type, 3 have only disc type ,15 have mixing type . The group with only endplate osteochondritis were all treated by conservative management. 37 cases with 40 involved discs among the 43 Modicl type accepted a second scan as follow-up after 1-3 years of interval. 25 discs transformed into Modic2 type completely, 10 discs transformed into Modic 2 type partially,5 discs were still maintained Modics 1 type. 25 cases presented varied degree of discal hemiation along the transformation from Modic 1 to Modic 2. Of the 11 who accepted follow-up scan among the 17 cases with Modic 2,all were maintained stable ,and 9 cases developed disc hemiation. Of the 341 cases accompanied with disc hemiation ,8 cases were verified after surgery,of which 5 cases were Modic 1,3 cases were Modic2. Among the 432 cases with endplate osteochondritis, 325 havelow back pain .accoutring for 75.2%, of which all disc type and the majority of Modic 1 type have symptom.Conclusion : Endplate osteochondritis is a kind of MRI findings of discdegeneration which results in low back pain. MRI is the best and first choice of modality for detecting it, which can definitely reflect different type and period of this entity .aiding in obtaining detail information. Paying attention to the MRI findings and clinical significance of this disease in practice will be beneficial to the timely diagnosis and treatment.