Screw-Related Complications After Instrumentation of the Osteoporotic Spine: A Systematic Literature Review With Meta-Analysis

Abstract

Study Design: Systematic literature review with meta-analysis. Objective: Osteoporosis is common in elderly patients, who frequently suffer from spinal fractures or degenerative diseases and often require surgical treatment with spinal instrumentation. Diminished bone quality impairs primary screw purchase, which may lead to loosening and its sequelae, in the worst case, revision surgery. Information about the incidence of spinal instrumentation-related complications in osteoporotic patients is currently limited to individual reports. We conducted a systematic literature review with the aim of quantifying the incidence of screw loosening in osteoporotic spines. Methods: Publications on spinal instrumentation of osteoporotic patients reporting screw-related complications were identified in 3 databases. Data on screw loosening and other local complications was collected. Pooled risks of experiencing such complications were estimated with random effects models. Risk of bias in the individual studies was assessed with an adapted McHarm Scale. Results: From 1831 initial matches, 32 were eligible and 19 reported screw loosening rates. Studies were heterogeneous concerning procedures performed and risk of bias. Screw loosening incidences were variable with a pooled risk of 22.5% (95% CI 10.8%-36.6%, 95% prediction interval [PI] 0%-81.2%) in reports on nonaugmented screws and 2.2% (95% CI 0.0%-7.2%, 95% PI 0%-25.1%) in reports on augmented screws. Conclusions: The findings of this meta-analysis suggest that screw loosening incidences may be considerably higher in osteoporotic spines than with normal bone mineral density. Screw augmentation may reduce loosening rates; however, this requires confirmation through clinical studies. Standardized reporting of prespecified complications should be enforced by publishers.

Junctional kyphosis and junctional failure after multi-segmental posterior cervicothoracic fusion – A retrospective analysis of 64 patients

“…Reduced bone density is known to be a major contributor to worse clinical outcomes after spinal fusion. [ 25 ] Interestingly, reduced bone mineral density did not seem to have an effect on the development for JK/JF in our study. Since DEXA scans were not available for all patients in our study, we chose to use the mean HU measured in the LIV on preoperative CT as a surrogate.…”

Posterior short segment fixation including the fractured vertebra combined with kyphoplasty for unstable thoracolumbar osteoporotic burst fracture

“…Posterior short segment fixation including the fractured vertebral has been widely applied for thoracolumbar fractures, this method can reduce the operation time and bloods loss, preserve motion segments compared to long-segment posterior fixation, and provide greater mechanical strength to prevent early implant failure compared with traditional 4-screws short-segment posterior fixation [ 17 ]. However, diminished bone quality in osteoporotic vertebral impairs primary screw purchase, and screw loosening incidences will be considerably higher than with normal bone mineral density, cement augmented screw fixation may reduce loosening risks [ 18 ]. Kim et al demonstrated cement augmented six screw fixation including the fractured vertebral is satisfactory in maintaining the deformity correction for the patients with severe osteoporotic burst fractures, the average amount of correction loss of the kyphotic was 2.0 degrees 15 months post-operation, and there were no signs of hardware pull-out, however, the reconstruction of the fractured vertebral was unacceptable, the height of the vertebral just increased from 35 and 40% to 70% in the anterior and middle portion [ 19 ].…”

Surgical treatment of a complex craniocervical malformation combined with posterior cranial fossa teratoma: a case report and literature review

“…The patient’s revision surgery also confirmed that this combined anterior-posterior approach was effective to achieve decompression. Screw loosening was considered to be related to severe osteoporosis in such patients [ 10 ] and stress concentration of internal fixation because of multi-segment cervical fusion. Therefore, preoperative radiography should be carefully evaluated, and postoperative external fixation measures should be taken forcefully without delay.…”