Lumbar spine mobility in Marfan syndrome. A clinical and radiological study.

Low back pain symptoms and lumbar spine mobility were assessed by questionnaires and by clinical and radiological measurements in 32 patients with Marfan syndrome. Frequently occurring low back pain was reported by 19% of the patients, but the disability was slight in all of them. Flexion and extension mobility of the lumbar spine (L1-S1) assessed from radiographs was 59.9 degrees and 13.2 degrees, respectively. Mean lumbar angular mobility between flexion and extension radiographs was 7.4 degrees at L1-2, 13.2 degrees at L2-3, 16.0 degrees at L3-4, 19.3 degrees at L4-5 and 18.3 degrees at L5-S1. No correlation was found between the manual assessment of lumbar segmental instability and radiological translatory motion, except at L2-3, where the correlation was negative (r = -0.41, P < 0.05). In conclusion, the prevalence of low back pain does not seem to differ substantially between Marfan syndrome patients and the normal population, and it seems that there is at most a slight hypermobility of the lumbar spine in Marfan syndrome. Several validity problems are encountered in the manual assessment of lumbar instability.