Harms mesh cages are commonly used in the treatment of metastatic spinal tumors by spondylectomy with cage insertion and posterior screw fixation. These cages are even useful for the surgical reconstruction of spinal deformities with mesh-cage replacement after vertebral column resection (VCR). Mesh cages can be customized by 3-dimensional (3D) printing based on the angle between the endplates for the requisite weight-bearing capacity and fit. This study reports two cases wherein a 75-year-old man and a 63-year-old woman were treated with reconstructive spondylectomy and mesh-cage replacement, followed by posterior screw fixation. The 75-year-old man was initially diagnosed with an L4 metastatic non–small cell lung carcinoma accompanied by a pathologic fracture and severe paralysis. The 63-year-old woman had slipped 13 years before and sustained a T11-L1 compression fracture that was aggravated 6 months before this admission, with back pain and numbness in both soles. Herein, we describe the treatment approach with instrumentation using a customized 3D-printed mesh cage after total spondylectomy for the metastatic spinal tumor and after VCR for deformity repair surgery in the respective cases. Our application of a 3D-printed mesh cage in surgery for a metastatic tumor is the first report of such treatment in Korea. Although the use of customized 3D-printed cages for a metastatic spinal tumor and a severe compression fracture was effective, challenges remain regarding fitting, manufacturing time, and costs.
Metastatic spinal tumors can cause back pain and paralysis by invading the spinal canal, which can result in pathologic fractures. Such fractures require spondylectomy with reconstruction using mesh cages
Traumatic compression fractures can cause back pain and limb numbness, specifically when the spinal canal is involved. When a compression fracture progresses, spinal stenosis and kyphosis can occur, and surgery for deformity correction is often required. In such cases, a mesh cage can support the reconstruction of the compressed vertebra after vertebral column resection (VCR) has been completed.
This study reports two cases wherein 3-dimensional (3D) mesh cages were constructed and used to treat a 75-year-old man with a metastatic pathologic fracture and severe paralysis and a 63-year-old woman with severe kyphosis and T11-L1 compression fracture. Herein, we document the approach to the treatment of these two cases using 3D-printed mesh cage. This is the first case of a patient with a metastatic spinal tumor receiving such treatment in Korea. The accumulation of similar case reports is required to increase the uptake of 3D-printed mesh cages in this context.
The patient was a 75-year-old man without any relevant medical history. He presented with low back pain and bilateral buttock pain (numeric rating scale [NRS] score of 4 points; wherein 0 to 10 points denoted no pain to extreme pain, respectively), which had persisted since July 2021. Magnetic resonance imaging (MRI) at another hospital revealed an L4-compression fracture (
Six days later, which was 2 days after the embolization of L3-L4 spinal arteries, L4-spondylectomy and L3-S1 posterior screw fixation were performed using a customized 3D-printed mesh cage (
The patient was a 63-year-old woman without any documented medical history. Approximately 13 years ago, she slipped and experienced aggravating back pain 3 months later. Subsequently, T11-L1 compression fracture was diagnosed and managed with conservative care, and her pain subsided. Her back pain resurfaced 6 months before presentation, when she lifted a heavy object and had numbness in both soles of the feet and a cold sensation in the legs, resulting in gait disturbance. She visited the emergency room and received conservative care through the outpatient clinic. No motor deficit was observed, but hypoesthesia was present in both feet. No abnormal deep tendon reflex was observed. Plain radiography (
Metastatic spinal tumors can cause pain and lower-limb weakness. Surgery, radiotherapy, or chemotherapy is required independently or in combination to treat such tumors. Spondylectomy with cage insertion and posterior screw fixation using a Harms cage is common
A previous report presented successful outcomes of the application of 3D-printed custom implants for severe bone loss, limb and joint arthrodesis, and spine surgery
The angle of the cage surface could be customized in the intervertebral space, given the angle between endplates required for efficient weight-bearing, a strength of a 3D-printed cage. The use of 3D-printed implants can be expanded for indications in spinal oncology, helping achieve tailored/precise treatment.
Furthermore, we concluded that a 3D-printed mesh cage is useful as a vertebral body replacement in severe compression fractures that can cause kyphosis. In our patient, the vertebral body had nearly collapsed due to severe compression fracture, losing its original structure. After the VCR of T11, the mesh cage was needed to compensate for the residual gap and correct the kyphosis. The 3D-printed mesh cage was constructed after considering the height between adjacent vertebral bodies and the angle between two adjacent endplates, and to ensure a tight fit for kyphosis correction. Given the good fit and no observed displacement, the 3D-printed mesh cage may be a good option for deformity surgeries.
The 3D-printed mesh cage device had certain limitations. Although the cage was customized, there were residual fitting issues, and the cage was slightly dislocated in the forward direction over time (
Reconstruction of metastatic spinal tumors and severe compression fracture using a customized 3D-printed cage showed acceptable results, although fitting problems, manufacturing time, and high costs remain to be managed.
We would like to thank Editage (
No potential conflict of interest relevant to this article was reported.
Preoperative imaging studies in case 1. (A) Initial magnetic resonance image (MRI) showing an L4-compression fracture (T2, T1 signal). (B) Contrast-enhanced computed tomography (CT) scan and plain radiograph of the chest, showing a mass in the left upper lobe (LUL). (C) Contrast-enhanced MRI, obtained on the day after admission, showing strong enhancement in L4 with spinal canal stenosis and a pathologic compression fracture, and (D) a positron emission tomography-CT scan showing uptake in the LUL, L4 body, and T1 body.
Postoperative imaging studies and a three-dimensional (3D)-printed cage model in case 1. (A) Contrast-enhanced magnetic resonance imaging (MRI) taken after decompression surgery and one radiotherapy session showing aggravation of L4 metastasis. (B) Customized mesh for the 3D-printed cage and 3D modeling of the product. (C) Postoperative plain radiography taken after instrumentation showing stable cage insertion. (D) One-month postoperative plain radiography showing slight forward displacement of the 3D-printed cage.
Preoperative imaging studies in case 2. (A) Initial radiography showing a severe compression fracture at the T11-L1 level with severe kyphosis. (B) Initial magnetic resonance T2-signal sagittal imaging showing a severe compression fracture at the T11-L1 level with severe kyphosis. (C) T1-signal sagittal image. (D) T2-signal axial image.
Imaging studies and three-dimensional (3D)-printed cage model in case 2. (A) Computed tomography (CT) scan of the T11-L1 vertebral compression fracture with severe kyphosis. (B) 3D reconstruction image on CT. (C) Customized mesh-type 3D-printed cage and 3D modeling of the product. (D, E) Postoperative plain radiographs of the 3D-printed mesh-cage and posterior screws inserted in the vertebral column after T11 total vertebral column resection.