Menapace Bryan, Mackenzie William, Ditro Colleen, Rogers Kenneth, Campbell Jeffery, Mackenzie William G Stuart
Shriners Children's Portland, Portland, OR.
Nemours Children's Health, Delaware, Wilmington, DE.
J Pediatr Orthop. 2025 Aug 1;45(7):431-437. doi: 10.1097/BPO.0000000000002955. Epub 2025 Mar 31.
Cervical spine atlantoaxial instability (AAI) is frequently encountered in skeletal dysplasias (SD), particularly in patients with collagen type 2 (COL2) mutations. The values of clinical examination, radiographic measurements, and magnetic resonance imaging (MRI) findings in determining when to intervene on COL2 AAI are unknown. The goal of this study is to compare these tools and report the utility and significance of each in surgical decision-making.
A retrospective case-control series from a single center's skeletal dysplasia database, 2007 to 2023, included COL2 patients that had documented history, examination, and flexion-extension (F-E) cervical spine radiographs and MRI. Radiographic measurements included dens morphology, anterior atlanto-dens interval (AADI), and posterior atlanto-dens interval (PADI). MRI measurements included cervical stenosis, C1 space available for the cord (SAC), and presence of myelomalacia. Criteria cutoffs were defined by receiver operating characteristic analysis and a scoring rubric was generated by internal validation.
Of all SD patients, 78 of 547 (14%) had COL2 syndromes, and 53 (68%) met all inclusion criteria. The most common diagnosis was spondyloepiphyseal dysplasia (65%). Patients were majority 54% female and 80% white. Ten (19%) underwent surgery at an average age of 4.3 years. There were no differences in AAI clinical histories ( P = 0.18). Physical examination revealed higher rates of hyperreflexia in the surgical group ( P = 0.0002). On radiographs, surgical patients had more os odontoidea ( P = 0.0001) and greater change in AADI and PADI ( P = 0.01 and P < 0.0001). On MRI, surgical patients had myelomalacia more frequently ( P < 0.0001), more severe stenosis ( P = 0.02), and greater change in SAC ( P = 0.01). receiver operating characteristic analysis defined 7 surgical cutoffs as follows: (1) presence of hyperreflexia, (2) radiographic os odontoid, (3 and 4) F-E radiographs with ≥5 mm change in AADI and/or PADI, (5) myelomalacia on MRI, (6) C1-C2 stenosis ≥80%, and (7) ≥1.5 mm of C1-C2 SAC change on F-E MRI. Applying those cutoffs, it was determined that 100% of patients with 0 to 1 criteria were able to be managed nonoperative. Conversely patients with 4 or more criteria present were indicated for surgery in 80% of cases.
This is the largest case series on AAI in SD patients with COL2-associated conditions. This study identified 7 criteria that could be used to indicate surgical intervention. Patients who had ≤1 of these factors did not undergo surgery, while those with ≥4 had a high propensity to be recommended for surgical stabilization.
Level III.
颈椎寰枢椎不稳（AAI）在骨骼发育不良（SD）中较为常见，尤其是在患有2型胶原（COL2）突变的患者中。临床检查、影像学测量和磁共振成像（MRI）结果在确定何时对COL2 AAI进行干预方面的价值尚不清楚。本研究的目的是比较这些工具，并报告每种工具在手术决策中的效用和意义。
一项来自单一中心2007年至2023年骨骼发育不良数据库的回顾性病例对照系列研究，纳入了有病史记录、体格检查以及颈椎屈伸（F-E）位X线片和MRI检查的COL2患者。影像学测量包括齿状突形态、寰齿前间隙（AADI）和寰齿后间隙（PADI）。MRI测量包括颈椎管狭窄、脊髓可用C1间隙（SAC）以及是否存在脊髓软化。通过受试者操作特征分析确定标准临界值，并通过内部验证生成评分标准。
在所有SD患者中，547例中有78例（14%）患有COL2综合征，53例（68%）符合所有纳入标准。最常见的诊断是脊椎骨骺发育不良（65%）。患者中女性占54%，白人占80%。10例（19%）患者平均在4.3岁时接受了手术。AAI的临床病史无差异（P = 0.18）。体格检查显示手术组的反射亢进发生率更高（P = 0.000²）。在X线片上，手术患者的齿状突骨化更多（P = 0.000¹），AADI和PADI的变化更大（P = 0.0¹和P < 0.000¹）。在MRI上，手术患者脊髓软化更常见（P < 0.000¹），狭窄更严重（P = 0.0²），SAC的变化更大（P = 0.0¹）。受试者操作特征分析确定了7个手术临界值如下：（1）存在反射亢进，（2）影像学上的齿状突骨化，（3和4）F-E位X线片上AADI和/或PADI变化≥5 mm，（5）MRI上的脊髓软化，（6）C1-C2狭窄≥80%，（7）F-E位MRI上C1-C2 SAC变化≥1.5 mm。应用这些临界值，确定0至1条标准的患者100%可进行非手术治疗。相反，存在4条或更多标准的患者在80%的病例中被建议手术。
这是关于COL2相关疾病的SD患者中AAI的最大病例系列研究。本研究确定了7条可用于指示手术干预的标准。这些因素中≤1条的患者未接受手术，而≥4条的患者极有可能被建议进行手术固定。
三级。
