Petre Benjamin M, Karp Jacqueline E, Riley Lee H
Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, Maryland, USA.
Orthopedics. 2012 Sep;35(9):e1449-52. doi: 10.3928/01477447-20120822-39.
This article describes a rare congenital abnormality of anterior and posterior C1 fusion failure presenting after an acute athletic injury to the fibrous nonunion. C1 congenital malformations are rare, occurring in approximately 2% of patients; even rarer are combined anterior and posterior arch malformations in the same patient. Posterior ring abnormalities are more common than anterior ring injuries (4.5:1, respectively). To the authors' knowledge, combined anterior and posterior ring congenital malformations with subsequent injury have not been previously described. In the current patient, a congenital failure of fusion of the anterior and posterior arches of C1 was identified. The anterior fibrous nonunion was injured while the patient played football, leading to transient neurologic injury and dysphagia from soft tissue swelling. The patient was initially diagnosed with an acute fracture at another facility; however, given advanced imaging, flexion and extension views, and a normal neurologic examination, the authors diagnosed a traumatized congenital defect. The injury healed with a short period of cervical collar immobilization and supportive measures. Such malformations are usually found incidentally, but they can be symptomatic after trauma. Images to distinguish these deficits can be difficult because the differences between chronic nonunions and congenital malformations are subtle. Surgery is rarely indicated for congenital malformations because they are often stable even after injury; however, they may predispose patients to neurologic injury in the future with high-risk activities. Because the current patient had an increased chance of future injury secondary to the lack of bone formation in the C1 vertebrae, he was restricted from participating in contact sports.
本文描述了一种罕见的先天性异常，即第一颈椎（C1）前后融合失败，在急性运动损伤后出现纤维性骨不连。C1先天性畸形很少见，约2%的患者会出现；同一患者同时存在前后弓畸形则更为罕见。后环异常比前环损伤更常见（分别为4.5:1）。据作者所知，此前尚未有关于合并前后环先天性畸形并继发损伤的描述。在当前患者中，发现了C1前后弓先天性融合失败。患者踢足球时，前部纤维性骨不连受伤，导致短暂性神经损伤和软组织肿胀引起的吞咽困难。该患者最初在另一家医疗机构被诊断为急性骨折；然而，鉴于先进的影像学检查、屈伸位片以及正常的神经学检查，作者诊断为创伤性先天性缺陷。通过短期佩戴颈托固定和支持性措施，损伤得以愈合。此类畸形通常是偶然发现的，但在创伤后可能出现症状。区分这些缺陷的影像学检查可能很困难，因为慢性骨不连和先天性畸形之间的差异很细微。先天性畸形很少需要手术治疗，因为即使受伤后它们通常也很稳定；然而，它们可能使患者在未来进行高风险活动时易发生神经损伤。由于当前患者因C1椎体缺乏骨形成，未来受伤的几率增加，因此他被限制参加接触性运动。
