S1 osteotomy L5-S1 monosegmental instrumented reduction and 360 degrees circumferential fusion for severe adolescent isthmic dysplastic spondylolisthesis

English Keywords:L5-S1 monosegmental instrumented reduction  360 degrees circumferential fusion  Severe adolescent dysplastic isthmic spondylolisthesis

English Abstract:

  【Abstract】 Objectives: Discuss the advantages, disadvantages and security of S1 osteotomy L5-S1 monosegmental instrumented reduction and 360 degrees circumferential fusion for severe adolescent isthmic spondylolisthesis. Methods: Ten adolescent patients with severe isthmic spondylolisthesis treated between September 2007 and September 2014 in the second Xiangya hospital of Central South University. All patients were average 15.8±2.6 years(12.5-18.0 years) and were treated by S1 osteotomy L5-S1 monosegmental instrumented reduction and 360 degrees circumferential fusion. The preoperative and postoperative Oswestry disability index(ODI), visual analog scale(VAS) pain score and spino-pelvic parameters measured using full-spine radiographs were retrospectively analyzed. Including the mean degree of slip, pelvic incidence(PI), sacral slope(SS), pelvic tilt(PT), lumbar lordosis(LL), thoracic kyphosis(TK), sacro-femoral distance(SFD), the horizontal distance between C7 plumb line and the posterior corner of the sacrum(SC7D), T9 tile angle, dubousser lumbosacral angle(Dub-LSA), lumbosacral joint angle(LSJA). Results: The average follow-up time was 38±6 months. The mean degree of slip was reduced from (78±17.5)% preoperative to (4.5±4.2)% postoperative. PI didn′t had obvious change, remained 74.5°±9.6°. SS increased from 45.1°±8.5° to 49.2°±9.1° and PT decreased from 29.4°±8.4° to 25.3°±6.3°. LL decreased from 65.0°±10.3° to 50.2°±8.8°, TK increased from 24.8°±7.1° to 37.2°±7.6°, SFD decreased from 58.1±12.4mm to 54.2±11.9mm, SC7D decreased from 51.6±37.8mm to 18.7±30.2mm, T9 tilting angle decreased from 8.2°±4.8° to 1.5°±4.5°, Dub-LSA increased from 76.6°±11.3° to 110.3°±12.4°, LSJA decreased from 32.1°±19.4° to 1.7°±12.3°. At the half year follow-up, the ODI decreased from (60±7.4)% to (9.5±2.1)%, and the VAS pain score decreased from 7.2±1.1 to 1.8±0.5. There were no permanent neurological injury, pseudarthrosis, muscular atrophy and no implant failures. One case appeard postoperative cerebrospinal fluid leakage, prolong drainage tube standing time to a week, wounds were healing well, without secondary infection. Only two patient had radicular pain in hip to back of the thighs postoperative a half year, which recovered fully with physical therapy. Conclusions: S1 osteotomy L5-S1 monosegmental instrumented reduction and 360 degrees circumferential fusion is a safe and effective surgical technique. This surgical technique can decrease neurological complications during reduction and restore sagittal profile of the spine.