青少年特发性脊柱侧凸术后远端附加现象的研究进展

Prevention,treatment and risk factors of postoperative distal adding-on phenomenon in adolescent idiopathic scoliosis

青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)是一种最常见的脊柱畸形,矫形术后可并发远端附加现象。远端附加现象常伴有不理想的临床和影像学结果,多见于选择性胸椎融合术后的患者,表现为主弯跨度向远端未融合椎体延伸。目前临床上常用的远端附加现象的定义为主弯下端椎向远端移动,主弯远端椎体数目增加且伴有远端融合椎下端第一椎体偏离骶骨中线增加5 mm以上或远端融合椎下第一椎间隙成角增加5°以上。远端附加现象发生的危险因素逐渐成为研究热点,远端融合椎的选择为最重要的危险因素。由于外科医生的标准不同,远端融合椎的选择也不尽相同,对此存在较大争议。远端附加现象的发生不是单个危险因素直接导致的结果,其他危险因素,包括骨骼成熟度、远端融合椎与骶骨中线的距离、L4倾斜分型、肩平衡、冠状面平衡、腰弯柔软度、主胸弯矫正率、远端融合椎旋转等。远端附加现象的进展对患者产生不良影响,导致不得不进行支具治疗甚至手术翻修。目前关于术后远端附加现象进展以及手术翻修指征的文献报道甚少。本文针对AIS患者术后发生远端附加现象的危险因素、预防以及治疗的研究现状进行综述。

Adolescent idiopathic scoliosis(AIS)is one of the most common deformities.Distal adding-on phenomenon,as one of the postoperative complications of AIS,results in unsatisfactory radiological and clinical outcomes.Moreover,it is more common in patients with selective thoracic fusion.It appears as an extension of the primary curve to the unfused distal vertebra.The most common used clinical definition of distal adding-on phenomenon is the distal migration of the lower end vertebra and progressive increase in the number of included distal vertebrae within the primary curve combined with either an increase of more than 5 mm in deviation of the first vertebra below the lowest instrumented vertebra from the center sacral vertical line or an increase of more than 5°in the angulation of the first disc below the lowest instrumented vertebra.The risk factors for distal adding-on phenomenon have become to a hotspot of research.Scholars have conducted lots of studies on the choice of the lowest instrumented vertebra,which is regarded as the most important risk factor.The choice of the lowest instrumented vertebra varies based on surgeons'decision due to the different criteria and still in controversy.However,the occurrence of distal adding-on phenomenon is not directly caused by a single risk factor.Some studies identified other risk factors,including skeletal maturity,distance between the lowest instrumented vertebra and the center sacral vertical line,L4 tilt score,shoulder balance,coronal balance,lumbar flexibility,main thoracic curve correction rate,the lowest instrumented vertebra rotation and so on.The development of distal adding-on phenomenon has negative effects on patients,such as brace treatment and even surgical revision.However,there is a limited number of literatures about the development of distal adding-on phenomenon and the indications of surgical revision.The present study reviews the current research status of the risk factors,prevention and treatment of postoperative distal adding-on phenomenon in AIS.