2026 年 13 巻 p. 389-392
Vertebral compression fractures (VCF) after radiation therapy (RT) are uncommon, particularly in the mid- and lower cervical spine. Surgical management of symptomatic cases can be challenging. Here, we report the case of a 63-year-old woman with radiculomyelopathy and C7 VCF. The patient presented with neck pain and bilateral hand numbness without osteoporosis. Four years previously, she had been cured of esophageal cancer through endoscopic surgery and RT without chemotherapy. Imaging revealed a pathological C7 vertebral body fracture with kyphotic deformity. Symptomatic VCF was diagnosed. Because of concerns regarding complications with an anterior approach, posterior-only decompression and fixation were performed. Intraoperative biopsy at C7 vertebra confirmed a diagnosis of avascular necrosis without metastasis. Fixation was performed by inserting lateral mass screw at C5−, 6 and pedicle screw at T1−, 2, connected by a rod. A multipoint screw was used to enhance rostral stability. The symptoms were alleviated postoperatively, and the patient remained well at 2-year follow-up.
Non-traumatic vertebral compression fractures, also known as Kummell's disease (KD), typically occur in the thoracolumbar spine of older women with osteoporosis or patients who undergo steroid treatment. KD represents avascular vertebral fracture, with RT identified as a risk factor.1) Vertebral fractures after RT in the mid- or lower cervical spine are extremely rare.2)
Here, we report a case of progressive cervical radiculomyelopathy due to a pathological C7 vertebral fracture after RT for esophageal cancer. Posterior decompression with biopsy and fixation surgery yielded favorable outcomes.
A 63-year-old woman with a history of neck pain presented to our clinic with worsening neck pain after a fall. Neurological examination revealed decreased sensation and numbness on the ulnar side of both upper limbs. No motor paralysis or lower limb symptoms were observed. Cervical spine magnetic resonance imaging showed vertebral body compression and spinal cord compression with low-to-intermediate signal intensity on T1WI and T2WI at C7 with a kyphotic deformity (Figure 1A and B) without enhancement. Three-dimensional computed tomography of the cervical spine revealed a C7 vertebra fracture with posterior displacement of bone fragments into the pharyngeal wall (Figure 1C) without osteoporosis. The patient's medical history included endoscopic submucosal dissection for esophageal cancer performed 4 years previously, followed by intensity-modulated RT (IMRT) without chemotherapy. This shows the radiation dose to each vertebral body from C5 to T2 during IMRT performed to prevent invasion (Figure 1D). On the basis of the clinical course and imaging findings, metastatic vertebral tumor or pathological fracture was created, leading to surgical intervention. Because of concerns about potential complications, such as esophageal damage due to adhesions or vertebral body fusion failure with an anterior cervical approach, intraoperative biopsy and posterior fixation procedure were planned. Fixation was performed using pedicle screws at T1, 2 caudally and lateral mass (LM) screws at C5−,6 cranially, with 2 LM screws above and two pedicle screws below T1−,2 (Figure 2A and B). To prevent cranial displacement, bilateral multi−point screws (MULTIPOINT SECURE™, DePuy Synthes) were connected to C5 using an offset connector (Figure 2C and D). Biopsy of the C7 pedicle revealed avascular necrosis without cancer cells (Figure 2E). Concerns were raised about bone fusion using the patient's own bone, so artificial bone was placed around the instrumentation in the hope of mechanical and fibrous union. Postoperatively, neurological symptoms were relieved, with no recurrence, including in the primary lesion, for 2 years postoperatively.
Initial cervical MRI reveals collapsed C7 vertebra and compression of the spinal cord from the front (A, B). Cervical 3D-CT reveals a C7 compression fracture, causing prolapse within the spinal canal and kyphotic deformity, and tear drop of bone fragments in the posterior pharyngeal wall (C). This shows a map of RT (intensity modulated radiotherapy [MRT] for residual esophageal cancer. The vertebral body radiation dose was 13.23-33.07 Gy at C6 and 42.99-52.91 Gy at C7-T1. A portion of the anterior part of the vertebral body at C7-T1 received 59.52 Gy (D).
3D: 3-dimensional; CT: computed tomography; MRI: magnetic resonance imaging; RT: radiation therapy
Postoperative MRI shows posterior decompression (A). Radiographs obtained after posterior fixation using rod-connected lateral mass screws at C5–, 6 and pedicle screws at T1–, 2 (B). In the 3D-CT scan, a MULTIPOINT SECURE is placed on C5, and strong fixation is performed with the transvers rod (C). In the C5 axial image, 2 screws are placed on each side of the lateral mass (D). Pathological specimens (H&E staining) from the C7 vertebral fracture intraoperatively reveals avascular necrosis (E).
3D: 3-dimensional; CT: computed tomography; H&E: hematoxylin and eosin; MRI: magnetic resonance imaging
Recently, stereotactic radiosurgery (SRS) as direct irradiation has attracted attention as a minimally invasive cancer treatment; however, reports of complications, such as vertebral compressive fractures (VCF), are occasionally observed.3-5) Al-Omair et al.3) reported 2 cases of vertebral fractures after SRS, and biopsies of these fractures revealed radiation-induced necrosis and fibrosis. A systematic review of VCF after SRS showed an incidence rate of 13.9%, with risk factors, including 1) osteolytic changes, 2) high-dose fractionated irradiation, 3) spinal deformity, 4) older age, and 5) tumor infiltration in > 40% to 50% of the vertebral body. Surgical treatment was performed in 37% of VCF cases.4) Khorsandi et al.5) reported mid- and lower cervical fractures due to necrosis after RT for head and neck cancer. In our case, the only applicable risk factor was high-dose radiation by IMRT exposure. A review by Sahgal et al.6) found that the risk of vertebral fracture after RT for spinal metastases was 11%-39%. Various measures have been implemented to minimize the VCF caused by SRS.5-7) In addition, Fujii et al.8) reported that the combined use of chemotherapy and RT increases the risk of vertebral fractures. Reports have highlighted the importance of early diagnosis and treatment of suppurative osteomyelitis of the cervical spine after RT for head and neck cancers.6-9) Therefore, the risk of complications from anterior cervical surgery after RT is something that needs to be avoided.
Cho et al.10) reported cases of anterior cervical corpectomy and fusion (ACCF) for cervical spine metastasis and investigated the effects of preoperative RT on intra-and postoperative outcomes. Consequently, there were no significant differences in wound adhesion, damage, or infection; however, a significant difference in vertebral body subsidence was observed in the RT group.10)
Osteoporotic VCF, including KD, are commonly observed at the thoracolumbar junction. This case occurred in the extremely rare C7 region, and we suspect it was caused by the load-bearing stress on the skull.
Recent developments and improvements in posterior cervical instrumentation have enabled posterior-only approaches, even in cases in which anterior cervical fusion is challenging, with favorable long-term results.11,12) Pedicle screws in the mid- and lower cervical spine provide strong fixation; however, they increase the risk of vertebral artery injury and nerve root damage. Conversely, LM screws have a lower risk of complications and are easier to insert; however, care must be taken to prevent screw loosening.12,13) We hypothesized that using a 2-screw multipoint system for LM screws at the most cranial end (C5) of the posterior system would help prevent screw pullout.
ConclusionsTissue adhesion after RT in the anterior cervical spine is a major concern. Although not an absolute contraindication for ACCF, it increases the risk of vertebral fusion failure owing to insufficient blood flow. Therefore, decompression and fixation surgery using posterior instrumentation with multipoint screw system could be considered for pathological fractures.
All authors have no conflict of interest.
Informed consent was obtained from the patient.
