Cortical bone trajectory fixation in cemented vertebrae in lumbar degenerative disease: A case report

Abstract

BACKGROUND

Percutaneous vertebroplasty (PVP) has been widely used in osteoporotic vertebral compression fracture (OVCF). Following surgery, the bone cement would be positioned permanently. However, in some cases of lumbar degenerative disease, the cemented vertebrae needs to be fixed after decompression and fusion procedure. It is difficult to implant traditional pedicle screws into the cemented vertebrae because of the bone cement filling. At present, the main treatment strategy is to skip the cemented vertebra and conduct a long segment fixation. This article presents a cortical bone trajectory (CBT) fixation technique for cemented vertebrae.

CASE SUMMARY

PVP involving the L3 and L4 was performed in an 82-year-old man due to OVCF. During the surgery, bone cement leakage occurred, resulting in compression of the root of the right L3 nerve. We performed a partial facetectomy to retrieve the leaked bone cement and to relieve the patient’s neurological symptoms. After 3 mo, the patient developed lumbar disc herniation in L3/4, potentially due to instability caused by the previous surgery. Therefore, it was necessary to perform intervertebral fusion and fixation. It was difficult to implant traditional trajectory pedicle screws in L3 and L4 because of the bone cement filling. Hence, we implanted CBT screws in the L3 and L4 vertebrae. As a result, the patient’s symptoms resolved and he reported satisfaction with the surgery at follow-up after 8 mo.

CONCLUSION

It is feasible to utilize CBT in cemented vertebrae for the treatment of lumbar degenerative disease.

Keywords: Cortical bone trajectory; Cemented vertebrae; Lumbar degenerative disease; Spinal fixation; Bone cement leakage; Case report

Core Tip: It is difficult to implant traditional trajectory (TT) pedicle screws in the cemented vertebrae. Cortical bone trajectory (CBT) may be a feasible method because of short implantation depth and location at the rear of the vertebrae. We successfully implanted CBT screws in the cemented vertebrae. The application of CBT provides a new method for the fixation of the cemented vertebrae and expands the indication for CBT. Meanwhile, we used two tips to decrease the rod curvature and simplify assembly in the hybrid screw technique for which CBT and TT were used in the same set.