来源：304关节学术

译者：张振东

整理：骨科在线

目前骶髂关节退行性改变的病因尚未完全阐明，有研究曾分析其与双下肢不等长之间存在相关性，即双下肢长度差异每增加1cm，骶髂关节传递负荷可增加5倍。而既往无研究对骶髂关节改变与髋关节畸形间的相关性进行报道。单侧髋关节发育不良多继发关节炎，且伴有不同程度的双下肢不等长问题，因此，本文作者通过研究分析了导致单髋发育不良继发重度骨关节炎患者发生骶髂关节退变的因素。

研究纳入了2008年1月至2015年11月行关节置换的单侧髋关节发育不良继发重度骨关节炎的患者，共152例。骶髂关节退变依据术前CT轴位结果分类，分别为型：无关节退变；1型：轻度关节退变；2型：重度关节退变及3型：骶髂关节融合（图1）。研究对比了双侧骶髂关节退变程度的差异，并分析不同退变分类患者的一般资料、髋关节及脊柱影像学数据（图2）等各指标的差异。

结果显示，单侧髋关节发育不良患者，下肢长的一侧更易发生骶髂关节退变。严重关节退变或关节融合的患者（2、3型）下肢长侧所占的比例高达62.5%，而下肢短侧该比例为33.6%。髋关节脱位程度、下肢不等长程度与下肢长侧骶髂关节退变严重程度呈正相关，而体重、BMI是下肢短侧骶髂关节发生退变的危险因素。患者体重越大、矢状面轴向垂线(sagittal vertical axis，SVA)越长，下肢短侧骶髂关节发生退变的程度越重，而患者双下肢长度差异越大，下肢长侧骶髂关节发生退变的程度越重。

图1 骶髂关节退变程度分类

a：型，无关节退变；b：1型，轻度关节退变；c：2型，重度关节退变；d：3型，骶髂关节融合

图2 脊柱测量指标  A 脊柱全长正位；B脊柱全长侧位。

Cobb angle：Cobb角；CVA：冠状面轴向垂线；PO骨盆倾斜角；Lumbar lordosis：腰椎前凸；Sacral slope：骶骨倾斜角；SVA：矢状面轴向垂线

因此，单侧髋关节发育不良继发重度骨关节炎的患者中，骶髂关节退行性改变为常见现象。下肢长侧骶髂关节退变程度与髋关节脱位程度密切相关。下肢短侧骶髂关节退变严重的患者，多伴有脊柱矢状面不平衡或具有体重大、BMI高的特点。

原文摘要

Sacroiliac joint degeneration is common in patients with end-stage hip osteoarthritis secondary to unilateral developmental dysplasia of the hip:Factors associated with its severity and laterality

Background:The etiology of sacroiliac joint (SIJ) degeneration has not been fully elucidated,and there has been almost no report on the relevance between SIJ degeneration and hip osteoarthritis secondary to developmental dysplasia of the hip (DDH).We investigated factors associated with SIJ degeneration,specifically its laterality in patients with end-stage hip osteoarthritis secondary to unilateral DDH.

Methods:We included 152 patients with end-stage unilateral hip osteoarthritis secondary to DDH who underwent primary THA between January 2008 and November 2015.SIJ degeneration was classified (type 0,no degenerative change,to type 3,ankyloses) using preoperative axial computed tomography.SIJ degeneration of the DDH (shorter leg) and contralateral (longer leg) sides was compared;differences in patient demographics and radiological parameters between SIJ degeneration of type 0 or 1 versus type 2 or 3 for the shorter and longer leg sides were analyzed.

Results:SIJ on the longer leg side showed more degenerative changes (p < 0.001).Substantial SIJ degeneration or ankylosis (type 2 or 3) was observed on 62.5% of longer leg sides and 33.6% of shorter leg sides.Factors significantly associated with SIJ degeneration severity were percent hip subluxation and leg length discrepancy for the longer leg side and body weight and body mass index (BMI) for the shorter leg side. Patients with worse degeneration on the shorter leg side (9.9%) had significantly larger BMI and longer sagittal vertical axis,whereas patients with worse degeneration on the longer leg side (46.7%) had significantly longer leg length discrepancy.

Conclusion:Severe SIJ degeneration was common in patients with end-stage hip osteoarthritis secondary to unilateral DDH.Patients with worse SIJ degeneration on the longer leg side had more hip subluxation,whereas patients with worse SIJ degeneration on the shorter leg (DDH) side tended to have sagittal spinal imbalance and greater body weight with larger BMI.

文献出处：Okuzu Y,Goto K,Shimizu Y,Kawai T,Kuroda Y,Matsuda S.J Orthop Sci. 2021 Jan;26(1):135-140.doi:10.1016/j.jos.2020.02.005.Epub 2020 Mar 3.