✓ Generating replacement tissues requires an interdisciplinary approach that combines developmental, cell, and molecular biology with biochemistry, immunology, engineering, medicine, and the material sciences. Because basic cues for tissue engineering may be derived from endogenous models, investigators are learning how to imitate nature. Endogenous models may provide the biological blueprints for tissue restoration, but there is still much to learn. Interdisciplinary barriers must be overcome to create composite, vascularized, patient-specific tissue constructs for replacement and repair. Although multistep, multicomponent tissue fabrication requires an amalgamation of ideas, the following review is limited to the new directions in bioabsorbable technology. The review highlights novel bioabsorbable design and therapeutic (gene, protein, and cell-based) strategies currently being developed to solve common spine-related problems.
Stephen M. Warren, Marc H. Hedrick, Karl Sylvester, Michael T. Longaker and Constance M. Chen
Benson P. Yang, Stephen L. Ondra, Larry A. Chen, Hee Soo Jung, Tyler R. Koski and Sean A. Salehi
he authors conducted a study to evaluate the radiographically documented and functional outcomes obtained in patients who underwent pedicle subtraction osteotomy (PSO). They also compared outcomes after classification of cases into thoracic and lumbar PSO subgroups.
he authors analyzed data obtained in 35 consecutive PSO-treated patients with sagittal imbalance. One surgeon performed all surgeries. The minimal follow-up period was 2 years. Events during the perioperative course and complications were noted. Standing long-film radiographs of the spine were obtained and measurements were made preoperatively, immediately postoperatively, and at most recent follow-up examination. The modified Prolo Scale and the 22-item Scoliosis Research Society (SRS-22) Outcomes Questionnaire were administered.
Early complications after PSO included neurological injury, wound-related problems, and nosocomial infections. Late complications were limited to pseudarthrosis and attendant instrumentation failure. Early and late complication rates ranged from 10 to 30% for both thoracic and lumbar PSO cohorts.
Lumbar PSO was associated with improvements in local, segmental, and global measures of sagittal balance, whereas thoracic PSO was only associated with local improvement. Most patients rated their functional status as fair to good according to the modified Prolo Scale and reported, according to the SRS-22 Outcomes Questionnaire, that they were satisfied with the overall treatment of their back condition.
The ability to perform a PSO at both lumbar and thoracic levels is a powerful asset for the spine surgeon treating spinal deformity. In the present study radiographic and clinical outcomes were superior when PSO was used to treat lumbar deformity rather than thoracic deformity because of several anatomical and technical obstacles that hindered the thoracic procedure. Nevertheless, the thoracic PSO proved a useful addition with which to produce regional improvement in sagittal balance for patients with a fixed thoracic kyphosis.
Stephen B. Lewis, Gregory J. Velat, Lynn Miralia, Linda Papa, Jada M. Aikman, Regina A. Wolper, Chris S. Firment, Ming Chen Liu, Jose A. Pineda, Kevin K. W. Wang and Ronald L. Hayes
Aneurysmal subarachnoid hemorrhage (ASAH) is a serious event with grave consequences. Delayed ischemic neurological deficits caused by cerebral arterial vasospasm contribute significantly to death and disability. Biomarkers may reflect brain injury and provide an early warning of impending neurological decline and stroke from ASAH-induced vasospasm. Alpha-II spectrin is a cytoskeletal protein whose breakdown products are candidate surrogate markers of injury magnitude, treatment efficacy, and outcome. In addition, αII spectrin breakdown products (SBDPs) can provide information on the proteolytic mechanisms of injury.
Twenty patients who received a diagnosis of Fisher Grade 3 ASAH were enrolled in this study to examine the clinical utility of SBDPs in the detection of cerebral vasospasm in patients with ASAH. All patients underwent placement of a ventriculostomy for continual cerebrospinal fluid drainage within 72 hours of ASAH onset. Cerebrospinal fluid samples were collected every 6 hours and analyzed using Western Blotting for SBDPs. Onset of vasospasm was defined as an acute onset of a focal neurological deficit or a change in Glasgow Coma Scale score of two or more points. All suspected cases of vasospasm were confirmed on imaging studies.
Both calpain- and caspase-mediated SBDP levels are significantly increased in patients suffering ASAH. The concentration of SBDPs was found to increase significantly over baseline level up to 12 hours before the onset of cerebral arterial vasospasm.
Differential expression of SBDPs suggests oncotic necrotic proteolysis may be predominant in acute brain injury after ASAH and cerebral arterial vasospasm.
Yi-Ren Chen, Beatrice Ugiliweneza, Eric Burton, Shiao Y. Woo, Maxwell Boakye and Stephen Skirboll
Glioblastoma is a primary glial neoplasm with a median survival of approximately 1 year. There are anecdotal reports that postoperative infection may confer a survival advantage in patients with glioblastoma. However, only a few case reports in the literature, along with 2 retrospective cohort studies, show some potential link between infection and prolonged survival in patients with glioblastoma. The objective of this study was to evaluate the effect of postoperative infection in patients with glioblastoma using a large national database.
The linked Surveillance, Epidemiology, and End Results (SEER)–Medicare database was searched to identify patients 66 years of age and older with glioblastoma, with and without infection, from 1997 to 2010. The primary outcome was survival after diagnosis. The statistical analysis was performed with a graphical representation using Kaplan-Meier curves, univariate analysis with the log-rank test, and multivariate analysis with proportional hazards modeling.
A total of 3784 patients with glioblastoma were identified from the database, and from these, 369 (9.8%) had postoperative infection within 1 month of surgery. In patients with glioblastoma who had an infection within 1 month of surgery, there was no significant difference in survival (median 5 months) compared with patients with no infection (median 6 months; p = 0.17). The study also showed that older age, increased Gagne comorbidity score, and having diabetes may be negatively associated with survival.
Infection after craniotomy within 1 month was not associated with a survival benefit in patients with glioblastoma.