Clinical, Imaging And Prevalence Study Of Degenerative Spinal Diseases In Southern Chinese

PartⅠ: Prevalence and types of abnormalities of the spine in urban southern Chinese: A study of 1,736 population MRI scans of the whole spine【Objective】To estimate the extent, prevalence, and distribution of degenerative changes of lumbar disc and some spinal structural abnormalities in an urban population of southern China. This study also determined the variation of these abnormalities in different age and gender groups.【Methods】A total of 1,736 urban southern Chinese volunteers (1068 women; 668 men) between 8 and 88 years of age (mean, 38.04 years) were recruited by open invitation. Radiologic examinations, clinical interviews, and physical examinations were administered to all the participants. T2-weighted, 5-mm spin-echo MRI sequences of the whole spine were obtained. On MRIs, disc degeneration and disc bulging were scored using our new methods. Schmorl nodes, high intensity zones, and marrow changes were assessed for each lumbar segment. The 2 observers reviewed together and settled by consensus differences.【Results】There was also a significant trend ( P<0.0005) for an overall association between Schmorl nodes and gender (higher in men). In chi-square test, increasing in the strengths, Schmorl nodes, marrow changes, and HIZ, were showed a significant positive association with LDD (OR:227.9, 20.2, 2.4, respectively; P<0.0005). There was also a statistically significant association between Schmorl nodes and marrow changes (OR 1.7; P<0.05). HIZ and marrow changes showed significant association with age(P<0.0005). The distributive sequence of the Schmorl nodes in lumbar in decreasing order is from upper to lower, but HIZ is in a reverse order in disc levels. Both DDD and bulge scores showed a significant positive association with BMI(P<0.0005).We found no significant difference in both scores between genders. Among the different areas of degeneration, there was a consistent increase in prevalence of LDD from the upper to lower disc levels. There was some variation in LDD across sex groups(P<0.05). The prevalence of LDD in younger were also high (35.3% in men and 33.9% in women).【Conclusions】Schmorl nodes differ greatly between genders and are not age-related changes. A high prevalence of LDD existed in this urban southern Chinese sample. BMI was found to be correlated with LDD. In young adults, degenerative disc findings are relatively common. Men aged 25 to 35 years are more likely to have LDD than women. We presumed that is attributed to environmental factors.PartⅡ: Correlation of MRI abnormalities and low back pain in a population study of 854 subjects【Objective】The authors perform a prospective, large scale study of quality of life and MRI findings in subjects from a general urban population of southern China with or without LBP in order to estimate the associations among LBP, DDD and some outcome measurements.【Methods】Intervertebral disc degeneration is part of ageing, and abnormalities on MRI scans can be found in asymptomatic individuals. To date, there is no large scale population study examining the relationship between MRI findings and symptoms of low back pain (LBP). A total of 854 volunteers (560 women; 294 men) between 16 and 63 years of age were recruited. All underwent a MRI examination of the lumbar spine and answered questions in relation to the presence and severity of LBP and sciatica. On MRIs, the severity of disc degeneration and herniation were scored by 2 experienced clinicians and differences were settled by consensus. Duration, frequency and severity of LBP were recorded if present. These subjects were also objectively assessed by the visual analogue scale (VAS), Oswestry Disability Index (ODI), Roland Morris Questionnaire (RMQ) and SF-36. 【Results】There was significant association between MRI findings of degeneration, herniation and LBP. RMQ, VAS, and physical function (PF) of the SF-36 were better than others as rating scales of LBP. Statistically significant correlations were found between three measurements (ODI, VAS, PF) and disc degenerative changes on MRI. ROC curve was used as a quantitative method for assessing a scale's ability to distinguish subjects who have DDD from those who have not. PF, VAS, and ODI showed significant but weak correlations with DDD. Their areas under ROC curve were 0.607, 0.596, and 0.583 respectively. The mental component summary of SF-36 in the subjects who only had sciatica was higher than those who had LBP.【Conclusions】Although conceding that certain structural degenerative abnormalities of the spine are common in general population, the present study has been able to show a significant association between DDD and the presence or severity of LBP. PF was relatively a better way to predict the presence of DDD and rate LBP.PartⅢ: Clinical imaging study and meta-analysis of ossification of the ligamentum flavum and posterior longitudinal ligament【Objective】To evaluate the prevalence, morphology and distribution of ossification of the ligamentum flavum (OLF) in a population, and provide appropriate guidelines for treatment of tandem ossification of the posterior longitudinal ligament (OPLL) and ligamentum flavum (OLF) using the method of systematic review.【Methods】A total of 1,736 southern Chinese volunteers were recruited between February 2001 and September 2006. Sagittal MRI was administered to all the participants. Presence of OLF was identified and subsequently confirmed by CT scans. The distribution of OLF was classified into three types. While the morphology of the lesion was classified into triangular, round and beak shapes. An English and Chinese literature search from January 1980 to December 2006 was conducted. The key words for search were OLF or OLF and OPLL.【Results】OLF was identified in a total of 66 subjects or 3.8% of the population. The isolated type was found in 45(68.2%) cases, continuous type in 11(16.7%), and non-continuous type in 10(15.2%). The majority of the segments had a round morphology (81.5%), while 17(18.5%) segments were triangular in shape. 4 articles that reported on the prevalence of OLF and 13 reports of tandem OPLL and OLF (TOO) were identified by the detailed review. All studies advocated that the primary therapy for TOO should be operative. The clinical outcomes of surgery were evaluated in most reports, predominantly using the JOA scores. A higher rate of women was found in the failure group of TOO. A new, two-stage, classification to aid selection of surgical technique in individual patients is presented.【Conclusion】This study demonstrated that OLF is not uncommon, and that some 15% of the lesions are non-continuous, and therefore could be missed. The authors recommend that for patients with suspected ossification of the spine should undergo routine MRI screening of the whole spine. The correlation of the classifications of TOO with surgical treatments is likely but needs to be examined in further studies.