Rodgers W B, Coran D L, Kharrazi F D, Hall J E, Emans J B
Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
J Pediatr Orthop. 1997 Nov-Dec;17(6):762-5.
Five children were treated before age 6 years with occipitocervical fusion for occipitocervical instability. Long-term (average, 11.8 years; range, 8.4-14.5 years) follow-up revealed increasing lordosis across the fused segment in four of the patients, a finding we here refer to as the occipitocervical crankshaft phenomenon. On average, occipitocervical lordosis increased 1.06 degrees per level fused per year until skeletal maturity. Although such a progression might be expected, to our knowledge this is the first report of its occurrence. Compensatory subaxial motion was able to overcome this increase in all of the patients. We recommend occipitocervical fusion in a neutral or slightly flexed position in the very young child to account for this predictable increase in lordosis.
5名6岁前的儿童因枕颈不稳接受了枕颈融合术。长期（平均11.8年；范围8.4 - 14.5年）随访发现，4例患者融合节段的前凸增加，我们将这一发现称为枕颈曲轴现象。平均而言，直到骨骼成熟，每融合一个节段枕颈前凸每年增加1.06度。尽管可能会出现这种进展，但据我们所知，这是关于其发生的首次报告。所有患者的下位颈椎代偿性活动都能够克服这种前凸增加。我们建议在非常年幼的儿童中于中立位或轻度屈曲位进行枕颈融合，以应对这种可预测的前凸增加。
