Instrumented Lumbar Corpectomy and Spinal Reconstruction Comparing rhBMP-2/Compression-Resistant Matrix, rhBMP-2/Absorbable Collagen Sponge/Ceramic Granules Mixture, and Autograft in Two Different Devices: A Study in Sheep

Study Design. Fusion success with rhBMP-2 and autograft in titanium or PEEK corpectomy devices was evaluated in a sheep lumbar corpectomy model. The 6 treatment groups included titanium mesh or PEEK corpectomy devices filled with rhBMP-2 on a compression-resistant matrix (CRM) carrier; rhBMP-2 in a morselized absorbable collagen sponge (ACS) carrier combined with resorbable ceramic granules; and autograft. Objective. The aim of this study was to determine fusion rates associated with 2 different preparations of rhBMP-2 as well as autograft in an instrumented ovine lumbar corpectomy model 6 months postoperatively. Summary of Background Data. Vertebral reconstruction with corpectomy devices requires bone graft. Bone graft substitutes have the potential to avoid a second operation, donor site pain, and attendant morbidity associated with autograft. Methods. Twenty-four sheep in 6 treatment groups underwent lumbar corpectomy via a retroperitoneal trans-psoas approach. Spines were reconstructed with autograft, rhBMP-2 on a CRM, or rhBMP-2 on an ACS mixed with ceramic granules. Grafting materials were placed in either a titanium mesh or PEEK conduit in spines with internal fixation. Computed tomographic (CT) scans were evaluated for fusion. Undecalcified histology was used to evaluate for fusion as well as the amount and extent of graft incorporation and graft resorption. Results. Regardless of corpectomy device used, rhBMP-2/CRM or rhBMP-2/ACS with MASTERGRAFT resulted in a 100% fusion rate. The autograft group had a lower (75%) radiographic fusion rate. Using either preparation of rhBMP-2 resulted in the length of the defect filling with solid bone. Autograft fragments and ceramic granules were incorporated into the fusion masses with much of the ceramic granules being resorbed by 6 months. Conclusion. Both of the rhBMP-2 formulations have the potential to effect bony fusion and vertebral reconstruction within the corpectomy devices

Iatrogenic Spinal Cord Injury Resulting From Cervical Spine Surgery.

STUDY DESIGN: Retrospective cohort study of prospectively collected data. OBJECTIVE: To examine the incidence of iatrogenic spinal cord injury following elective cervical spine surgery. METHODS: A retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network was conducted. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, were reviewed to identify occurrence of iatrogenic spinal cord injury. RESULTS: In total, 3 cases of iatrogenic spinal cord injury following cervical spine surgery were identified. Institutional incidence rates ranged from 0.0% to 0.24%. Of the 3 patients with quadriplegia, one underwent anterior-only surgery with 2-level cervical corpectomy, one underwent anterior surgery with corpectomy in addition to posterior surgery, and one underwent posterior decompression and fusion surgery alone. One patient had complete neurologic recovery, one partially recovered, and one did not recover motor function. CONCLUSION: Iatrogenic spinal cord injury following cervical spine surgery is a rare and devastating adverse event. No standard protocol exists that can guarantee prevention of this complication, and there is a lack of consensus regarding evaluation and treatment when it does occur. Emergent imaging with magnetic resonance imaging or computed tomography myelography to evaluate for compressive etiology or malpositioned instrumentation and avoidance of hypotension should be performed in cases of intraoperative and postoperative spinal cord injury

Incidence and Outcomes of Acute Implant Extrusion Following Anterior Cervical Spine Surgery.

STUDY DESIGN: Multi-institutional retrospective case series of 8887 patients who underwent anterior cervical spine surgery. OBJECTIVE: Anterior decompression from discectomy or corpectomy is not without risk. Surgical morbidity ranges from 9% to 20% and is likely underreported. Little is known of the incidence and effects of rare complications on functional outcomes following anterior spinal surgery. In this retrospective review, we examined implant extrusions (IEs) following anterior cervical fusion. METHODS: A retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, were reviewed to identify occurrence of 21 predefined treatment complications. RESULTS: Following anterior cervical fusion, the incidence of IE ranged from 0.0% to 0.8% across 21 institutions with 11 cases reported. All surgeries involved multiple levels, and 7/11 (64%) involved either multilevel corpectomies or hybrid constructs with at least one adjacent discectomy to a corpectomy. In 7/11 (64%) patients, constructs ended with reconstruction or stabilization at C7. Nine patients required surgery for repair and stabilization following IE. Average length of hospital stay after IE was 5.2 days. Only 2 (18%) had residual deficits after reoperation. CONCLUSIONS: IE is a very rare complication after anterior cervical spine surgery often requiring revision. Constructs requiring multilevel reconstruction, especially at the cervicothoracic junction, have a higher risk for failure, and surgeons should proceed with caution in using an anterior-only approach in these demanding cases. Surgeons can expect most patients to regain function after reoperation

Outcomes following laminoplasty or laminectomy and fusion in patients with myelopathy caused by ossification of the posterior longitudinal ligament: A systematic review

Study Design Systematic review. Objective To compare laminoplasty versus laminectomy and fusion in patients with cervical myelopathy caused by OPLL. Methods A systematic review was conducted using PubMed/Medline, Cochrane database, and Google scholar of articles. Only comparative studies in humans were included. Studies involving cervical trauma/fracture, infection, and tumor were excluded. Results Of 157 citations initially analyzed, 4 studies ultimately met our inclusion criteria: one class of evidence (CoE) II prospective cohort study and three CoE III retrospective cohort studies. The prospective cohort study found no significant difference between laminoplasty and laminectomy and fusion in the recovery rate from myelopathy. One CoE III retrospective cohort study reported a significantly higher recovery rate following laminoplasty. Another CoE III retrospective cohort study reported a significantly higher recovery rate in the laminectomy and fusion group. One CoE II prospective cohort study and one CoE III retrospective cohort study found no significant difference in pain improvement between patients treated with laminoplasty versus patients treated with laminectomy and fusion. All four studies reported a higher incidence of C5 palsy following laminectomy and fusion than laminoplasty. One CoE II prospective cohort and one CoE III retrospective cohort reported that there was no significant difference in axial neck pain between the two procedures. One CoE III retrospective cohort study suggested that there was no significant difference between groups in OPLL progression. Conclusion Data from four comparative studies was not sufficient to support the superiority of laminoplasty or laminectomy and fusion in treating cervical myelopathy caused by OPLL

Clinical Outcomes After Four-Level Anterior Cervical Discectomy and Fusion.

Study Design: Retrospective cohort study. Objectives: Anterior cervical discectomy and fusion (ACDF) demonstrates reliable improvement in neurologic symptoms associated with anterior compression of the cervical spine. There is a paucity of data on outcomes following 4-level ACDFs. The purpose of this study was to evaluate clinical outcomes for patients undergoing 4-level ACDF. Methods: All 4-level ACDFs with at least 1-year clinical follow-up were identified. Clinical outcomes, including fusion rates, neurologic outcomes, and reoperation rates were determined. Results: Retrospective review of our institutional database revealed 25 patients who underwent 4-level ACDF with at least 1-year clinical follow-up. Average age was 57.5 years (range 38.2-75.0 years); 14 (56%) were male, and average body mass index was 30.2 kg/m Conclusions: Review of our institution\u27s experience demonstrated a low rate of revision cervical surgery for any reason of 8% at mean 19 months follow-up, and neurological examinations consistently improved, despite a high rate of radiographic nonunion (31%)

Clinical and magnetic resonance imaging characteristics of thoracolumbar intervertenral disk extrusions and protrusions in large breed dogs

It has recently been shown that the fat-derived hormone adiponectin has the ability to decrease hyperglycemia and to reverse insulin resistance. However, bacterially produced full-length adiponectin is functionally inactive. Here, we show that endogenous adiponectin secreted by adipocytes is post-translationally modified into eight different isoforms, as shown by two-dimensional gel electrophoresis. Carbohydrate detection revealed that six of the adiponectin isoforms are glycosylated. The glycosylation sites were mapped to several lysines (residues 68, 71, 80, and 104) located in the collagenous domain of adiponectin, each having the surrounding motif of GXKGE(D). These four lysines were found to be hydroxylated and subsequently glycosylated. The glycosides attached to each of these four hydroxylated lysines are possibly glucosylgalactosyl groups. Functional analysis revealed that full-length adiponectin produced by mammalian cells is much more potent than bacterially generated adiponectin in enhancing the ability of subphysiological concentrations of insulin to inhibit gluconeogenesis in primary rat hepatocytes, whereas this insulin-sensitizing ability was significantly attenuated when the four glycosylated lysines were substituted with arginines. These results indicate that full-length adiponectin produced by mammalian cells is functionally active as an insulin sensitizer and that hydroxylation and glycosylation of the four lysines in the collagenous domain might contribute to this activity.link_to_subscribed_fulltex

Cervical Deformity Patients Have Baseline Swallowing Dysfunction but Surgery Does Not Increase Dysphagia at 3 Months: Results From a Prospective Cohort Study.

Study designProspective cohort study.ObjectivesMost studies of dysphagia in the cervical spine have focused on a degenerative patient population; the rate of dysphagia following surgery for cervical deformity (CD) is unknown. This study aims to investigate if surgery for cervical deformity results in postoperative dysphagia.MethodsPatients with CD undergoing surgery from 2013 to 2015 were prospectively enrolled to evaluate dysphagia. Demographic, operative, and radiographic variables were analyzed. The Quality of Life in Swallowing Disorders (SWAL-QoL) was used to measure dysphagia. Paired t test, independent t tests, and bivariate Pearson correlations were performed.ResultsA total of 88 CD patients, aged 61.52 ± 10.52 years, were enrolled. All patients (100%) had 3-month SWAL-QoL for analysis. The baseline preoperative SWAL-QoL was 78.35. This is roughly the same level of dysphagia as an anterior cervical discectomy patient that is 3 weeks removed from surgery. Increasing body mass index (BMI) was correlated with decreased SWAL-QoL score (r = -0.30, P = .001). Age, gender, smoking, and Charlson Comorbidity Index (CCI) showed no significant correlations with preoperative SWAL-QoL. Patients with prior cervical surgery had a lower preoperative SWAL-QoL (P = .04). While 11 patients had acute postoperative dysphagia, CD surgery did not result in lower SWAL-QoL at 3 months (77.26 vs 78.35, P = .53). Surgical variables, including estimated blood loss (EBL), anterior or posterior fusion levels, steroid use, preoperative traction, staged surgery, surgical approach, anterior corpectomy, posterior osteotomy, and UIV (upper instrumented vertebrae) location, showed no impact on postoperative SWAL-QoL. Correction of cervical kyphosis was not correlated to 3-month SWAL-QoL scores or the change in SWAL-QoL scores.ConclusionsWhile patients undergoing surgery for cervical deformity had swallowing dysfunction at baseline, we did not observe a significant decline in SWAL-QoL scores at 3 months. Patients with prior cervical surgery and higher BMI had a lower baseline SWAL-QoL. There were no surgical or radiographic variables correlated to a change in SWAL-QOL score

Corticosteroid Administration to Prevent Complications of Anterior Cervical Spine Fusion: A Systematic Review.

Study Design: Systematic review. Objectives: Anterior cervical approach is associated with complications such as dysphagia and airway compromise. In this study, we aimed to systematically review the literature on the efficacy and safety of corticosteroid administration as a preventive measure of such complications in anterior cervical spine surgery with fusion. Methods: Following a systematic literature search of MEDLINE, Embase, and Cochrane databases in July 2016, all comparative human studies that evaluated the effect of steroids for prevention of complications in anterior cervical spine surgery with fusion were included, irrespective of number of levels and language. Risk of bias was assessed using MINORS (Methodological Index for Non-Randomized Studies) checklist and Cochrane Back and Neck group recommendations, for nonrandomized and randomized studies, respectively. Results: Our search yielded 556 articles, of which 9 studies (7 randomized controlled trials and 2 non-randomized controlled trials) were included in the final review. Dysphagia was the most commonly evaluated complication, and in most studies, its severity or incidence was significantly lower in the steroid group. Although prevertebral soft tissue swelling was less commonly assessed, the results were generally in favor of steroid use. The evidence for airway compromise and length of hospitalization was inconclusive. Steroid-related complications were rare, and in both studies that evaluated the fusion rate, it was comparable between steroid and control groups in long-term follow-up. Conclusions: Current literature supports the use of steroids for prevention of complications in anterior cervical spine surgery with fusion. However, evidence is limited by substantial risk of bias and small number of studies reporting key outcomes