Department of Spine Surgery, Ganga Hospital, Coimbatore, India.
J Bone Joint Surg Am. 2018 Jul 5;100(13):1147-1156. doi: 10.2106/JBJS.17.01127.
There is a lack of a classification system providing uniformity in description and guiding management decisions for kyphotic spinal deformities. We developed such a classification based on column deficiency, flexibility of disc spaces, curve magnitude, and correlation with the corrective osteotomy required.
A classification was developed based on analysis of 180 patients with thoracolumbar kyphosis requiring osteotomy. The deformity was classified as Type I if the anterior and posterior columns were intact (IA indicated mobile disc spaces and IB, ankylosed segments). Type II indicated deficiency of only 1 column (IIA = anterior column and IIB = posterior column). Type III indicated deficiency of both columns (IIIA = kyphosis of ≤60°, IIIB = kyphosis of >60°, and IIIC = buckling collapse). A prospective analysis of 76 patients was performed to determine interobserver variability and the ability of the classification to guide selection of osteotomies of increasing complexity, including the Ponte osteotomy, pedicle subtraction osteotomy, disc bone osteotomy, single vertebrectomy, multiple vertebrectomies, and anterior in situ strut fusion procedure.
The mean age of the 76 patients was 21.2 years, the mean kyphosis was 69.9° (range, 26° to 120°), and the mean follow-up duration was 30 months. Six deformities were classified as IA, 5 as IB, 5 as IIA, 2 as IIB, 13 as IIIA, 35 as IIIB, and 10 as IIIC. Four surgeons classifying the deformities had a high agreement rate (kappa = 0.83), with the highest agreement for Types IA, IB, and IIIB. A correlation between the type of deformity and the osteotomy performed demonstrated that the classification could indicate the type of osteotomy required. All 18 patients with Type-I or II kyphosis were treated with Ponte, pedicle subtraction, or disc bone osteotomy. Forty-three (90%) of the 48 patients with Type IIIA or IIIB underwent vertebrectomy (single in 27 [56%] and multiple in 16 [33%]), and only 5 (10%) underwent disc bone osteotomy. Seven of the 10 patients with Type-IIIC kyphosis were treated with multiple vertebrectomies, with 5 of them needing preoperative halo gravity traction; the other 3 patients underwent an anterior in situ strut fusion procedure.
The proposed classification based on the morphology of column deficiency, flexibility, and curve magnitude demonstrated a high interobserver agreement and ability to guide selection of the appropriate osteotomy.
A novel classification system for kyphosis based on spinal column deficiency, flexibility of disc spaces, and curve magnitude would bring uniformity in management and help guide surgeons in the choice of the appropriate corrective osteotomy.
目前缺乏一种能在描述上提供统一性并指导脊柱后凸畸形管理决策的分类系统。我们基于脊柱柱缺失、椎间盘活动度、曲度大小以及与所需矫正截骨术的相关性，开发了这样一种分类系统。
我们基于需要截骨术的 180 例胸腰椎后凸患者的分析，开发了一种分类方法。如果前柱和后柱完整，则将畸形分为 I 型（IA 表示活动的椎间盘间隙，IB 表示僵硬的节段）。如果仅存在 1 个柱缺失，则为 II 型（IIA=前柱，IIB=后柱）。如果 2 个柱均缺失，则为 III 型（IIIA=曲度≤60°，IIIB=曲度＞60°，IIIC=后凸畸形伴塌陷）。我们对 76 例患者进行了前瞻性分析，以确定观察者间的变异性以及该分类系统指导选择越来越复杂的截骨术的能力，包括 Ponte 截骨术、经椎弓根截骨术、椎间盘骨截骨术、单椎体切除术、多椎体切除术和前路原位支撑融合术。
76 例患者的平均年龄为 21.2 岁，平均后凸角为 69.9°（范围 26°至 120°），平均随访时间为 30 个月。6 例畸形为 IA 型，5 例为 IB 型，5 例为 IIA 型，2 例为 IIB 型，13 例为 IIIA 型，35 例为 IIIB 型，10 例为 IIIC 型。4 位对畸形进行分类的外科医生具有较高的一致性评分（kappa=0.83），IA、IB 和 IIIB 型的一致性最高。畸形类型与所施行的截骨术之间的相关性表明，该分类系统可以提示所需的截骨术类型。所有 I 型或 II 型后凸的 18 例患者均接受了 Ponte、经椎弓根截骨术或椎间盘骨截骨术治疗。48 例 IIIA 或 IIIB 型患者中，43 例（90%）接受了椎体切除术（27 例为单椎体切除术[56%]，16 例为多椎体切除术[33%]），仅 5 例（10%）接受了椎间盘骨截骨术。10 例 IIIC 型患者中，7 例接受了多椎体切除术，其中 5 例术前接受了 halo 重力牵引；其余 3 例接受了前路原位支撑融合术。
基于脊柱柱缺失、椎间盘活动度和曲度大小的形态提出的分类方法具有较高的观察者间一致性，并能指导选择合适的截骨术。
一种基于脊柱柱缺失、椎间盘活动度和曲度大小的新型脊柱后凸分类系统将提供管理上的统一性，并有助于指导外科医生选择合适的矫正截骨术。
