Bone Cement-augmented Screw Fixation Research Articles

Clinical efficacy of bone cement augmented screw fixation for the severe osteoporotic spine.

ObjectiveTranspedicular instrumentation of the osteoporotic spine is a challenge for the spine surgeon due to the probability of screw loosening and the potential possibility of nonunion. The purpose of this study was to evaluate the clinical efficacy of bone cement augmented screw fixation in patients with severe osteoporosis.MethodsBetween February 2004 and August 2007, 250 patients with severe osteoporosis (T-score on BMD < -3.0) that had screw fixation were included in this study. The patients were divided into two groups (Group I: 157 patients that underwent bone cement augmented screw fixation that had a variety of spine spinal diseases including fractures, and Group II: 93 patients with severe osteoporosis that had screw fixation without bone cement augmentation). The imaging and clinical features were analyzed, including bone cement augmented levels, fusion rate and related complications. The visual analog scale (VAS), Oswestry disability questionnaire (ODI) and modified MacNab's criteria were used for the assessment of pain and functional capacity.ResultsIn both groups, a significant improvement in the VAS and ODI was achieved. 146 out of 157 patients (93%) in Group I and 83 out of 93 patients (90%) in Group II were graded as an excellent or good result according to the modified MacNab's criteria. None of the patients experienced serious complications. However, there were two cases with neurological deterioration as a result of bone cement extravasation in Group I. For Group II, there were five cases of screw loosening that required re-operation for bone cement augmentation.ConclusionWhether bone cement augmentation was performed or not, it was possible to achieve satisfactory results in patients with severe osteoporosis. However, if used carefully, bone cement augmented transpedicular screwing can reduce screw loosening and pullout in patients with severe osteoporosis.

Spondylolisthesis Accompanying Bilateral Pedicle Stress Fracture at Two Vertebrae

There has been no report of bilateral pedicle stress fractures involving two vertebrae. The authors describe a unique case of spondylolisthesis accompanying a bilateral pedicle stress fracture involving two vertebrae. De novo development of spondylolisthesis at the L5-S1 vertebrae accompanying a bilateral pedicle stress fracture at L4 and L5 was observed in a 70-year-old woman. The patient's medical history was unremarkable and she did not have any predisposing factors except severe osteoporosis. Interbody fusion with bone cement augmented screw fixation was performed. Surgical treatment resulted in good pain management and improved functional recovery.

A case of posterior element fracture in Kummell's disease

Kummell's disease is a rare, delayed posttraumatic collapse of a vertebral body that can occur several months or even years after an osteoporotic compression fracture. However, there are few reports of posterior element fractures associated with Kummell's disease. A 72-year-old man who had sustained an L1 osteoporotic compression fracture 14 months prior was admitted to our institution with incapacitating back pain. Plain radiographs showed progressive collapse of the L1 vertebral body and severe kyphosis at the thoracolumbar junction. Magnetic resonance imaging revealed a posterior element fracture as well as osteonecrosis of the L1 vertebral body. An L1 percutaneous vertebroplasty was performed, followed by bone cement-augmented screw fixation to maintain stability and correct the kyphotic deformity. After surgery, pain relief was immediate, and the patient was able to walk unassisted. This case illustrates that continuous axial distraction stress caused by aggravated kyphosis secondary to Kummell's disease may result in posterior element fractures. Our discussion concludes with a literature review.

Bone Cement Augmented Screw Fixation for Severe Osteoporotic Spine: Large Series of Clinical Application

Objective: The purpose of this study was to evaluate the clinical efficacy of bone cement augmented screw fixation for the patients accompanying severe osteoporosis. Methods: Between February 2004 and August 2007, 157 patients with various spinal diseases including fractures accompanying severe osteoporosis underwent a bone cement augmented screw fixation (947 levels). About 4.8cc of polymethylmethacrylate was injected into the each vertebral body through transpedicular route. We divided the patients into two groups (Group I: Posterior fusion for compression/burst fractures or idiopathic scoliosis, Group Ⅱ: Interbody fusion for various spinal diseases). Imaging and clinical features were analyzed, including bone cement augmented levels, fusion rate, clinical outcome and complications. The visual analog scale (VAS), Oswestry disability questionnaire and modified MacNab’s criteria were used for the assessment of pain and functional capacity. Results: In both groups, a significant improvement in VAS and Oswestry disability questionnaire was achieved. 146 out of 157 patients (93%) were graded as excellent or good result according to the modified MacNab’s criteria. None of the patients experienced operative death, screw pullout or cut-up. However, there were two cases of neurologic deterioration as a result of bone cement extravasation. Conclusion: Bone cement augmented transpedicular screwing can reduce the possibility of screw loosening and pullout in patients with severe osteoporosis.