Advances in surgical strategies for ossification of posterior longitudinal ligament involving the C 2 segment / 中国修复重建外科杂志

OBJECTIVE@#To evaluate the application of surgical strategies for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) involving the C 2 segment.@*METHODS@#The literature about the surgery for cervical OPLL involving C 2 segment was reviewed, and the indications, advantages, and disadvantages of surgery were summarized.@*RESULTS@#For cervical OPLL involving the C 2 segments, laminectomy is suitable for patients with OPLL involving multiple segments, often combined with screw fixation, and has the advantages of adequate decompression and restoration of cervical curvature, with the disadvantages of loss of cervical fixed segmental mobility. Canal-expansive laminoplasty is suitable for patients with positive K-line and has the advantages of simple operation and preservation of cervical segmental mobility, and the disadvantages include progression of ossification, axial symptoms, and fracture of the portal axis. Dome-like laminoplasty is suitable for patients without kyphosis/cervical instability and with negative R-line, and can reduce the occurrence of axial symptoms, with the disadvantage of limited decompression. The Shelter technique is suitable for patients with single/double segments and canal encroachment >50% and allows for direct decompression, but is technically demanding and involves risk of dural tear and nerve injury. Double-dome laminoplasty is suitable for patients without kyphosis/cervical instability. Its advantages are the reduction of damage to the cervical semispinal muscles and attachment points and maintenance of cervical curvature, but there is progress in postoperative ossification.@*CONCLUSION@#OPLL involving the C 2 segment is a complex subtype of cervical OPLL, which is mainly treated through posterior surgery. However, the degree of spinal cord floatation is limited, and with the progress of ossification, the long-term effectiveness is poor. More research is needed to address the etiology of OPLL and to establish a systematic treatment strategy for cervical OPLL involving the C 2 segment.

Stability and interbody fusion of augmented pedicle screws with bone cement for lumbar spondylolisthesis accompanied with osteoporosis / 中国组织工程研究

BACKGROUND: In lumbar spondylolisthesis patients with severe osteoporosis, screw is easily loose and pul s out during reposition, or loss of reduction and internal fixation failure easily occur after repair. Therefore, it is very important to elevate the intensity of pedicle screw fixation during repair. At present, few studies concern application of bone cement screw enhancement technology in lumbar spondylolisthesis patients with osteoporosis. OBJECTIVE: To investigate the clinical value of augmented pedicle screw with polymethylmethacrylate for lumbar spondylolisthesis accompanied with osteoporosis. METHODS: From June 2009 to June 2011, 27 patients suffering from lumbar spondylolisthesis accompanied with osteoporosis were included in this retrospective study. These patients received augmented pedicle screw with polymethylmethacrylate. The levels of disability and pain were evaluated by Oswestry Disability Index and visual analog scale. The internal fixation and fusion were evaluated by radiological findings. Al complications were recorded. RESULTS AND CONCLUSION: Al cases were fol owed up for 15-37 months. Oswestry Disability Index and visual analog scale scores were significantly better in final fol ow-up than that pre-treatment (P < 0.05). Imaging results revealed that bone cement tightly connected to bone interface. The position of screw and bone cement was good. Symptomatic bone cement leakage was not found. No fixation failure was detected during final fol ow-up. Al patients achieved interbody fusion. These results suggested that polymethylmethacrylate bone cement could increase the gripping force of the pedicle screw in osteoporotic vertebral body. It is safe and effective to treat spondylolisthesis accompanied with osteoporosis with augmented pedicle screws. Satisfactory fixation stability and interbody fusion can be obtained.