Asymptomatic Osseous Loose Body in the Cervical Spine
病例报道：无症状的颈椎内骨性游离体[来源于JBJS的文章，本人翻译]
Loose bodies or osteochondral fragments are commonly found in human joints. They are presumed to arise from trauma joint disintegration (for example degenerative changes) or synovial proliferation. The natural history of loose bodies in synovial joints is slow enlargement with deposition of additional surface layers. However if the loose body becomes trapped and reattaches to the synovium it is then generally reabsorbed. Neuropathic or degenerative joints with hyperemic or inflamed synovium are particularly prone to the development of loose bodies but they also tend to rapidly reabsorb them. Histological studies have generally demonstrated varying amounts of osseous cartilaginous and fibrous tissue with living and dead osteocytes chondrocytes osteoclasts and osteoblasts found in the tissue layers. No blood supply nourishes these loose bodies therefore they derive sustenance from the synovial fluid alone.
     在人类的关节中可以经常发现有游离体或骨块的存在，有研究表明创伤、关节退化，或者滑膜增生都可能导致增大。游离体的形成是一个慢慢的，逐层沉积的过程。然而，如果游离体被卡或附着在滑膜上，一般都会被吸收。研究表明伴有充血、炎症滑膜的关节神经痛或者退行性关节炎很可能会产生游离体，但是也容易被吸收。组织学上的研究普遍认为能在活的和死的骨细胞、软骨细胞、破骨细胞、骨细胞中能发现不同程度的骨软骨纤维组织。没有血供营养这些游离体；因此，它们只能从滑膜液中得到营养。

We report the case of a patient with an asymptomatic osseous loose body lying in the spine canal. To our knowledge this is the first time this condition has been reported in the literature.
以下是首例无症状椎管内骨性游离体的报道。

Case Report
病例报道[color]
an eighty-seven-year-old female restrained driver was involved in a low-speed motor-vehicle accident and sustained an open left tibiotalar fracture-dislocation. She had no loss of consciousness and had no pain numbness or weakness in the neck and/or the upper extremities. She reported no previous history of neck pain or upper-extremity radicular symptoms. Examination revealed no tenderness of the paraspinal tissues or the spinous processes neurological examination of all four limbs was normal. There was full painless range of motion of the cervical spine with no Hoffmann sign. The left ankle wound was irrigated the fracture-dislocation was reduced and the ankle was placed in a splint in the emergency department.
    一位87岁老年女性，在一次低速的摩托车与机车相撞中被困在车内，伴有左踝开放性脱位骨折。当时无昏迷，颈部和上肢都无麻木疼痛、乏力。患者自诉既往无颈痛或上肢的神经根症状。查体示脊柱旁组织、棘突压痛（-），四肢神经系统检查正常，颈椎各方位活动未引出疼痛，Hoffmann征（-）。急诊室予冲洗左踝伤口，复位后以甲板固定处理。

Routine trauma radiographs including radiographs of the cervical spine were made. The lateral radiograph of the cervical spine demonstrated severe cervical spondylosis . Computed tomography scans revealed marked spondylosis throughout the cervical spine calcification of the ligamentum flavum and one large oval osteochondral fragment lying within the cervical spinal canal at the level of C6 to C7. The fragment had the same average density (mean 350-400 HU [Hounsfield units]) as the vertebrae. The diameters of the loose body were 1.58 × 1.34 × 0.57 cm and the loose body occupied a considerable portion of the spinal canal on the axial cross section. This fragment had no apparent donor site and had smooth surfaces. A number of osteophytes at multiple other levels were identified as the cause of mild stenosis. The patient was placed in a cervical collar and underwent emergent surgery for the purpose of irrigation débridement and provisional fixation of the ankle fracture-dislocation.