Longer follow-up continues to reveal no increased risk of cancer with the use of recombinant human bone morphogenetic protein in spine fusion.

BACKGROUND CONTEXT: Large observational studies on potential oncogenic effects of recombinant human bone morphogenetic protein (rhBMP) in spine fusion surgery are limited by relatively short follow-up times. PURPOSE: To study the possible association between rhBMP and cancer risk in a long-term follow-up study. STUDY DESIGN: A retrospective cohort study using a combination of the Washington State Comprehensive Hospital Abstract Reporting System, the Washington State Cancer Registry, State of Washington death certificates, and the Washington State Department of Licensing. PATIENT SAMPLE: Participants were adults age ≥21 years who underwent spine fusion surgery enhanced by rhBMP for degenerative spine disease between January 1, 2002 and December 31, 2010. A comparison group matching each patient receiving rhBMP with three patients not receiving rhBMP was created using the indicators of age, sex, and year of treatment. We excluded patients receiving spine fusion for vertebral fractures or infection, and those with a diagnosis of cancer before or at the index procedure. OUTCOME MEASURES: The primary outcome was the first diagnosis of any cancer as identified in the records of the state cancer registry or death certificate through the end of 2015. METHODS: We compared cancer risk between those receiving spine fusion with and without rhBMP using survival analysis. We calculated incidence rates (hazards) by computing the ratio of the number of events and total time at risk. Unadjusted hazard ratios (HR) and adjusted HR (aHR) and their respective 95% confidence intervals (CI) were calculated assuming a Cox proportional hazard regression model. We adjusted the model to include the site of surgery (lumbar vs. cervical) as a covariate as this differed in frequency between the two treatment groups. To assess whether rhBMP adversely affects the progression of cancer, we compared mortality between rhBMP users and nonusers in those who developed cancer. Research support toward this study was received from Medtronic Sofamor Danek USA. The investigators alone, and not Medtronic, were solely responsible for the design, conduct, analysis, and reporting of this study. RESULTS: We included 16,914 patients who had spine fusion, of whom 4,246 received rhBMP. During the study period, 1,342 patients were diagnosed with some form of cancer. The incidence rate was similar between the two groups: 11.2 per 1,000 person years in the rhBMP group and 10.4 per 1,000 person years in the non-rhBMP group, with an aHR of 0.96; 95% CI, 0.85 to 1.10. Similarly, rhBMP use was not associated with an increased risk of commonly occurring individual cancer types, nor with cancer specific mortality after a cancer diagnosis, aHR, 0.92; 95% CI, 0.69 to 1.22. CONCLUSIONS: Long-term follow-up confirms previous findings that rhBMP application treated with elective spinal fusion did not result in an increased cancer risk in a large population of US adults.

Catastrophic Cervical Spine Injuries in Contact Sports.

Study Design Systematic review. Objectives To determine the incidence of catastrophic cervical spine injuries (CCSIs) among elite athletes participating in contact team sports and whether the incidence varies depending on the use of protective gear or by player position. Methods Electronic databases and reference lists of key articles published from January 1, 2000, to January 29, 2016, were searched. Results Fourteen studies were included that reported CCSI in rugby (n = 10), American football (n = 3), and Irish hurling (n = 1). Among Rugby Union players, incidence of CCSI was 4.1 per 100,000 player-hours. Among National Football League players, the CCSI rate was 0.6 per 100,000 player-exposures. At the collegiate level, the CCSI rate ranged from 1.1 to 4.7 per 100,000 player-years. Mixed populations of elite and recreational rugby players in four studies report a CCSI rate of 1.4 to 7.2 per 100,000 player-years. In this same population, the scrum accounted for 30 to 51% of total reported CCSIs in Rugby Union versus 0 to 4% in Rugby League. The tackle accounted for 29 to 39% of injuries in Rugby Union and 78 to 100% of injuries in Rugby League. Making a tackle was responsible for 29 to 80% of injuries in American football. Conclusion CCSIs are infrequent among elite athletes. There is insufficient evidence to determine the effect of protective gear (e.g., helmets, padding) on CCSI incidence. Scrum and tackle in rugby and tackling in American football account for the majority of CCSIs in each respective sport.

The Risk of Cancer With the Use of Recombinant Human Bone Morphogenetic Protein in Spine Fusion.

STUDY DESIGN: Retrospective cohort study using the Washington State Comprehensive Hospital Abstract Reporting System, the Washington State Cancer Registry, and Washington State death certificates. OBJECTIVE: To study the possible association between recombinant human bone morphogenetic protein (rhBMP) and cancer risk. SUMMARY OF BACKGROUND DATA: The use of rhBMP in spine fusion surgery remains controversial with respect to its possible role in tumorigenesis. METHODS: We compared adults who underwent spine fusion for degenerative disease with and without rhBMP between 2002 and 2010. Patients were matched on the basis of age, sex, and year of treatment. We excluded patients with a diagnosis of cancer before or at the index procedure. The primary outcome was the first diagnosis of cancer as identified in the records of the cancer registry. RESULTS: We included 16,914 patients who had spine fusion, of whom 4246 received rhBMP. During the study period, 449 patients received a diagnosis of cancer: 117 (2.76% of 4246) in the rhBMP group and 332 (2.62% of 12 668) in the no rhBMP group. The incidence rate was similar between the rhBMP and no rhBMP 9.5 and 9.0 per 1000 person years, respectively (hazard ratio, 1.06; 95% confidence interval, 0.86-1.30). There were no differences in the rate of cancer between the two groups in subgroups defined on the basis of site of fusion or surgical method. CONCLUSION: There was no increase in overall cancer incidence among those receiving rhBMP. An important limitation of this and other studies of rhBMP and cancer that have been conducted to date is their relatively limited duration of follow-up. The examination of cancer incidence following rhBMP administration must continue beyond just the first several years to adequately assess the potential of rhBMP to influence the occurrence of one or more types of malignancy. LEVEL OF EVIDENCE: 3.

Treating the Aging Spine.

Demographic trends make it incumbent on orthopaedic spine surgeons to recognize the special challenges involved in caring for older patients with spine pathology. Unique pathologies, such as osteoporosis and degenerative deformities, must be recognized and treated. Recent treatment options and recommendations for the medical optimization of bone health include vitamin D and calcium supplementation, diphosphonates, and teriparatide. Optimizing spinal fixation in elderly patients who have osteoporosis is critical; cement augmentation of pedicle screws is promising. In the management of geriatric odontoid fractures, nonsurgical support with a collar may be considered for low-demand patients, whereas surgical fixation is favored for high-demand patients. Management of degenerative deformity must address sagittal plane balance, which includes consideration of pelvic incidence. Various osteotomies may prove helpful in this setting.

Comparison of the safety outcomes between two surgical approaches for anterior lumbar fusion surgery: anterior lumbar interbody fusion (ALIF) and extreme lateral interbody fusion (ELIF).

PURPOSE: To review the evidence on safety of anterior lumbar interbody fusion (ALIF) and extreme lateral transpsoas interbody fusion (ELIF) in the treatment of degenerative spinal disorders with an emphasis on the association between neuromonitoring and complications. METHODS: We performed a systematic literature search in the Cochrane (CENTRAL), MEDLINE, EMBASE and the FDA Medical Devices databases. We abstracted information on study design, sample size, population, procedure, number and location of involved levels, follow-up time and complications, as well as information on conflict of interest and source of funding. In addition, for ELIF we collected information on the use of neuromonitoring during the procedure. RESULTS: 34 publications were included in the review: 24 ELIF (all case series), 9 ALIF (8 randomized controlled trials and 1 case series) and one retrospective cohort that directly compared ELIF with ALIF. 18 out of 24 ELIF studies reported using neuromonitoring. The overall complication rate for ELIF was lower compared to ALIF without FDA reports (16.61 vs. 26.47 %, respectively). However, the rate of neurologic complications in ELIF was almost twice as high compared to ALIF without FDA reports (8.92 and 4.96 %, respectively). The rate of overall complications in ELIF studies that were reported using neuromonitoring was lower compared to the studies that did not report using neuromonitoring (16.34 vs. 21.74 %, respectively). CONCLUSION: Although the overall complications rate for ELIF was lower compared to ALIF, ELIF is associated with a greater risk of neurological complications compared to ALIF even when used with neuromonitoring.

Treating the Aging Spine.

Demographic trends make it incumbent on orthopaedic spine surgeons to recognize the special challenges involved in caring for older patients with spine pathology. Unique pathologies, such as osteoporosis and degenerative deformities, must be recognized and dealt with. Recent treatment options and recommendations for the medical optimization of bone health include vitamin D and calcium supplementation, diphosphonates, and teriparatide. Optimizing spinal fixation in elderly patients with osteoporosis is critical; cement augmentation of pedicle screws is promising. In the management of geriatric odontoid fractures, nonsurgical support with a collar may be considered for the low-demand patient, whereas surgical fixation is favored for high-demand patients. Management of degenerative deformity must address sagittal plane balance, including consideration of pelvic incidence. Various osteotomies may prove helpful in this setting.

Extending public health: the Rockefeller Sanitary Commission and hookworm in the American South.

The Rockefeller Sanitary Commission for the Eradication of Hookworm Disease (1909-1914) fielded a philanthropic public health project that had three goals: to estimate hookworm prevalence in the American South, provide treatment, and eradicate the disease. Activities covered 11 Southern states, and Rockefeller teams found that about 40% of the population surveyed was infected. However, the commission met strong resistance and lacked the time and resources to achieve universal county coverage and meet project goals. We explore how these constraints triggered project changes that systematically reshaped project operations and the characteristics of the counties surveyed and treated. We show that county selectivity reduced the project's initial potential to affect hookworm prevalence estimates, treatment, and eradication in the American South.

Vascularized fibular grafts in patients with avascular necrosis of femoral head: a systematic review and meta-analysis.

BACKGROUND: Vascularized fibular grafting (VFG) has been initiated to treat avascular necrosis of the femoral head (ANFH) since the late 1970s. There are a number of review articles updating the use of VFG to treat the ANFH. None of them applied statistical analysis for combining results from different studies to obtain a quantitative estimate of the overall effect and potential harm of VFG in comparison to other treatment. METHODS: Several electronic databases were searched to find studies using VFG to treat ANFH. The outcomes sought included Harris Score, failure rate (conversion to total hip arthroplasty (THA) and/or femoral head collapse), and complications rate. Included studies were assessed for methodological bias and estimates of effect were calculated. Potential reasons for heterogeneity were explored. RESULTS: The clinical results of 69.0 % of VFG-treated patients and 25.0 % of non-VFG-treated patients were good to excellent (OR 0.13; p < 0.01). The conversion rate to THA of VFG-treated and that of other methods treated hips was 16.5 % and 42.6 % (OR 0.19; p < 0.001). Collapse rate of VFG-treated and that of non-VFG-treated hips was 16.7 % and 63.6 % (OR 0.09; p < 0.05). The complication rate of VFG-treated and that of other methods treated patients was 23.8 % and 8.9 % (OR 3.44; p = 0.09). For Steinberg stage I, II ANFH, failure rate of VFG-treated and that of non-VFG-treated hips was 9.8 % and 40.2 % (OR 0.17; p < 0.001). For Steinberg stage II, III ANFH, failure rate of VFG-treated and that of non-VFG-treated hips was 16.5 % and 42.8 %, respectively (OR 0.17; p < 0.001). CONCLUSIONS: VFG is a justified method that can prevent the ANFH from progressing to collapse, and that can retard or avoid hip replacement, especially in the hips of Steinberg stage I, II, and III.

The use of rhBMP in spine surgery: is there a cancer risk?

STUDY DESIGN: Systematic review. STUDY RATIONALE: Some have noted several safety issues associated with the use of bone morphogenetic proteins (BMPs), including cancer risk, stating both BMP and their receptors had been isolated from human tumors. In addition, data presented to the US Food and Drug Administration (FDA) on the product AMPLIFY™ (rhBMP-2, 40 mg) revealed a higher number of cancers in the investigational group compared with the control. OBJECTIVE: To independently review the cancer risk of rhBMP-2 use in spine fusion as published in the peer-reviewed literature and in the publicly available FDA data summaries. METHODS: A systematic review of the literature was undertaken for articles published through January 2012. Pubmed, Cochrane, National Guideline Clearinghouse Databases as well as bibliographies of key articles were searched. Two independent reviewers revised articles. Inclusion and exclusion criteria were set and each article was subjected to a predefined quality-rating scheme. RESULTS: Five published peer-reviewed studies and two FDA safety summaries reported the occurrence of cancer in patients treated with spinal fusion using rhBMP-2 or rhBMP-7. Cancer data for on-label use of rhBMP-2 (InFUSE™) were reported in the FDA data summary but not in one published pivotal study. The risk of cancer was same in both the rhBMP-2 and control groups, 0.7% after 24 months. Off-label use of rhBMP for posterolateral fusion (PLF) was associated with a slightly higher risk of cancer compared with controls in three randomized controlled trials and one poorly conducted retrospective cohort study at various follow-ups. In PLF the risk of cancer was 3.8% using 40 mg of BMP-2 compared with 0.9% in the control group. Two RCTs evaluating rhBMP-7 reported a cancer risk of 12.5% and 5.6% in the rhBMP-7 group compared with 8.3% and 0% in the control groups, respectively. The differences in these studies were not statistically significant; however, the sample sizes for these studies were small. CONCLUSIONS: Cancer risk with BMP-2 may be dose dependent, illustrating the need to continue to study this technology and obtain longer follow-up on patients currently enrolled in the FDA trials. Additionally, refined guidelines regarding the routine use of BMPs should be developed, taking into account the FDA summary data that is not routinely scrutinized by the practicing surgeon.

The lateral transpsoas approach to the lumbar and thoracic spine: A review.

BACKGROUND: In the last several years, the lateral transpsoas approach to the thoracic and lumbar spine, also known as extreme lateral interbody fusion (XLIF) or direct lateral interbody fusion (DLIF), has become an increasingly common method to achieve fusion. Several recent large series describe several advantages to this approach, including less tissue dissection, smaller incisions, decreased operative time, blood loss, shorter hospital stay, reduced postoperative pain, enhanced fusion rates, and the ability to place instrumentation through the same incision. Indications for this approach have expanded and now include degenerative disease, tumor, deformity, and infection. METHODS: A lateral X-ray confirms that the patient is in a truly lateral position. Next, a series of tubes and dilators are used, along with fluoroscopy, to identify the mid-position of the disk to be incised. After continued dilation, the optimal site to enter the disk space is the midpoint of the disk, or a position slightly anterior to the midpoint of the disk. XLIF typically allows for a larger implant to be inserted compared to TLIF or PLIF, and, if necessary, instrumentation can be inserted percutaneously, which would allow for an overall minimally invasive procedure. RESULTS: Fixation techniques appear to be equal between XLIF and more traditional approaches. Some caution should be exercised because common fusion levels of the lumbar spine, including L4-5 and L4-S1, are often inaccessible. In addition, XLIF has a unique set of complications, including neural injuries, psoas weakness, and thigh numbness. CONCLUSION: Additional studies are required to further evaluate and monitor the short and long-term safety, efficacy, outcomes, and complications of XLIF procedures.

Comparison of mini-open anterior corpectomy and posterior total en bloc spondylectomy for solitary metastases of the thoracolumbar spine.

OBJECT: The object of this study was to compare the mini-open anterior corpectomy procedure with posterior total en bloc spondylectomy (TES) in treating patients with solitary metastases of the thoracolumbar spine. METHODS: From 2004 to 2010, 41 patients with solitary metastases of the thoracolumbar spine were treated in our hospital using either a mini-open anterior corpectomy or posterior TES. Intraoperative and diagnostic data, including perioperative complications, were collected using retrospective chart review. The surgical outcomes were assessed according to survival status, neurological function, local recurrence, and pain before and after surgery. RESULTS: Seventeen patients underwent posterior TES and 24 underwent mini-open anterior corpectomy. Mean blood loss (TES, 1721 ± 293 ml; mini-open corpectomy, 1058 ± 263 ml; p < 0.05), and mean operative time (TES, 403 ± 55 minutes; mini-open corpectomy, 175 ± 38 minutes; p < 0.05) were recorded and calculated. Neurological improvement by at least 1 American Spinal Injury Association Impairment Scale grade was noted in 35 (97.2%) of the 36 cases with preoperative deficits. After the operation, 68.4% of nonambulatory patients became ambulatory again, including 84.6% after mini-open corpectomy and 33.3% after posterior TES (p > 0.05). The visual analog scale scores of the patients were significantly reduced after both procedures, with no difference between the procedures (p > 0.05). The local tumor recurrence rate of the TES group was significantly lower than that of the mini-open corpectomy group (p < 0.05), while the postoperative survival rates within 2 years after surgery were similar. The complication rate in the mini-open corpectomy group (29.2%) was higher than that in the TES group (11.8%), but this difference was not statistically significant (p = 0.185). There was no hardware failure and no loss of the sagittal Cobb angle in either group. Slight subsidence (< 3 mm) of the mesh cage was observed with a successful fusion in 3 (17.6%) of 17 patients in the TES group. No subsidence of polymethylmethacrylate block/autograft was recorded in the mini-open group. CONCLUSIONS: Mini-open anterior corpectomy can be accomplished with less blood loss, fewer fixation instrumentations, and shorter surgical time than that required for TES, but patients who undergo a mini-open corpectomy might have a greater tendency to experience local recurrence. A mini-open anterior corpectomy has a relatively mild learning curve and involves fewer technical difficulties. With smaller incisions, mini-open anterior corpectomy is an option in treating solitary metastases of the thoracolumbar spine.

Dual fibular allograft dowel technique for sacroiliac joint arthrodesis.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To assess fusion rates in patients with sacroiliac joint (SIJ) pain following a minimally invasive technique using fibular dowel allograft. METHODS: Thirty-seven consecutive patients (mean age: 42.5 years [range, 23-63 years]) with SIJ pain treated with 38 minimally invasive elective SIJ arthrodeses were retrospectively reviewed using chart and x-ray data. The fusion procedure consisted of minimal muscle stripping over the posterior SIJ and insertion of a cranial and caudal fibular dowel graft across the joint following placement of Steinmann pins. Fusion was deemed to be present when bone bridging trabeculae could be seen crossing the SIJ on either oblique x-rays or by computed tomographic scan. Patients were followed-up for a mean of 52 months (range, 24-62 months). Visual Analog Scale (VAS) was used to monitor clinical pain improvement. RESULTS: Thirty-four patients with SIJ arthrodeses (89.5%) healed and led to substantial improvement in VAS pain scores (preoperative 9.1, postoperative 3.4) (P < .001). This improvement in VAS occurred over a 6-month period and was sustained through subsequent follow-up. Nonunion occurred in four patients with SIJ (10.5%). Each SIJ nonunion was successfully treated by secondary autogenous bone grafting and compression screw fixation. CONCLUSIONS: In patients with primary low back pain attributable to the SIJ, a minimally invasive, dual fibular dowel graft provided high rates of fusion and improved pain scores. [Table: see text].

Platelet-rich plasma effects on degenerative disc disease: analysis of histology and imaging in an animal model.

STUDY DESIGN: Randomized controlled animal trial. OBJECTIVES: To analyze the early and late phase effects of platelet-rich plasma (PRP) injection into and around the damaged intervertebral disc using an animal model, and to evaluate the needle puncture technique in creating a degenerative disc model. METHODS: The L4-L5 intervertebral disc of 18 adult Sprague-Dawley rats was injured with a 21-gauge needle. Animals received an immediate injection of PRP, or a delayed injection of PRP 2 weeks postinjury, or no further intervention (sham) (n = 6/group). Six uninjured controls were used. Magnetic resonance imaging (MRI) was performed for a control at time 0 and each group at 4 weeks postinjury, this allowed resolution of inflammation and an accurate assessment of healing. Specimens were collected from immediate PRP group at 2 and 4 weeks postinjury, and the delayed PRP group at 4 and 6 weeks postinjury. The sham and control specimens were collected at 2, 4, and 6 weeks postinjury. Each disc was sectioned and analyzed subjectively for overall structure, cellularity, and water content (utilizing MRI). Disc height was measured using descriptive statistics and one-way analysis of variance (ANOVA) with Tukey post hoc analysis. It was presumed both groups injected with PRP would have better outcomes than the sham group. RESULTS: The sham group had clear degenerative changes with loss of organizational structure, empty space, fibrous tissue, and inflammatory cells, indicating needle puncture leads to degeneration. The PRP treated groups had fibers that were damaged with empty spaces and inflammatory cells. However, there was maintenance of the ring structure and the nucleus appeared to have a healthy central portion. Overall, both PRP - treated groups retained more normal morphologic features, contained fewer inflammatory cells, and had higher fluid content on MRI; however the effect was more pronounced in the immediate injection group. The disc height was significantly different in the sham and immediate injection group at the 4-week interval. CONCLUSIONS: This percutaneous needle puncture technique is an effective method for creating a degenerative disc model without posterior destabilization of the spine. The administration of PRP has a protective effect on damaged discs in the acute and delayed injection settings representing clinical treatment with PRP in the early versus late stages of the degenerative process. It appears that earlier intervention in the disease process would be more beneficial than PRP treatment of already severely degenerated discs.

Lumbar posterolateral fusion with local bone graft plus bone extender compared with iliac crest bone graft: a systematic review.

STUDY DESIGN: Systematic review. Study rationale and context: Bone graft from the iliac crest has been the gold standard in posterolateral spinal fusion procedures, but is associated with chronic pain at the harvest site. Bone graft harvested locally from the spine and combined with extenders may decrease the morbidity associated with iliac graft harvest, but questions remain on the success of this technique to achieve bone union. OBJECTIVES: Compare the fusion rate, functional outcomes, and safety of local bone graft plus bone extender compared with iliac crest bone graft in posterolateral spinal fusion procedures. METHODS: A systematic review of the literature was undertaken for articles published through January 2011. Pubmed, Cochrane, National Guideline Clearinghouse Databases, and bibliographies of key articles were searched. Two independent reviewers studied the articles. Inclusion and exclusion criteria were set and each article was subject to a predefined quality-rating scheme. RESULTS: We identified three articles meeting our inclusion criteria. Fusion rates were high across studies, with no significant differences between treatment groups in fusion, functional outcomes, or quality of life. There were two deep infections (5.3%) in one study among patients receiving local bone graft plus extender. CONCLUSION: Local bone graft plus bone extender has similar fusion rates, functional outcomes, and patient quality-of-life scores as iliac crest bone graft in posterolateral spinal fusion procedures. Additional randomized trials with standardized methods of measuring fusion and functional outcomes are needed.

Blood loss in major spine surgery: are there effective measures to decrease massive hemorrhage in major spine fusion surgery?

STUDY DESIGN: Systematic review. OBJECTIVE: To determine the definition and incidence of significant hemorrhage in adult spine fusion surgery, and to assess whether measures to decrease hemorrhage are effective. SUMMARY OF BACKGROUND DATA: Significant hemorrhage and associated comorbidities in spine fusion surgery have not yet been clearly identified. Several preoperative and intraoperative techniques are currently available to reduce blood loss and transfusion requirements such as cell saver (CS), recombinant factor VIIa, and perioperative antifibrinolytic agents, such as aprotinin, tranexamic acid, and epsilon-aminocaproic acid. Their effectiveness and safety in spine surgery is uncertain. METHODS: A systematic review of the English-language literature was undertaken for articles published between January 1990 and April 2009. Electronic databases and reference lists of key articles were searched to identify published studies examining blood loss in major spine surgery. Two independent reviewers assessed the quality of the literature using the Grading of Recommendations Assessment, Development, and Evaluation criteria. Disagreements were resolved by consensus. RESULTS: A total of 90 articles were initially screened, and 17 ultimately met the predetermined inclusion criteria. No studies were found that attempted to define significant hemorrhage in adult spine surgery. We found that there is a high level of evidence that antifibrinolytic agents reduce blood loss and the need of transfusion in adult spine surgery; however, the safety profile of these agents is unclear. There is very low evidence to support the use of CS, recombinant factor VIIa, activated growth factor platelet gel, or normovolemic hemodilution as a method to prevent massive hemorrhage in spine fusion surgery. CONCLUSION: There is no consensus definition of significant hemorrhage in adult spine fusion surgery. However, definition in the anesthesiology literature of massive blood loss is somewhat arbitrary but is commonly accepted to entail loss of 1 volume of the patient's total blood (60 mL/kg in adults) in <24 hours. On the basis of the current literature, there is little support for routine use of CS during elective spinal surgery. Concerns related to the use of aprotinin were such that our panel of experts unanimously recommended against its use in spine surgery on the basis of the reports of increased complications. With respect to the antifibrinolytics of the lysine analog class (tranexamic acid and aminocaproic acid), on the basis of the available efficacy and safety data, we recommend that they be considered as possible agents to help reduce major hemorrhage in adult spine surgery.

Dynamic anterior cervical plating for multi-level spondylosis: Does it help?

STUDY DESIGN: Randomized controlled trial. OBJECTIVE: To compare fusion rates, time to fusion, complication rates and subsidence between 1) a static, 2) a dynamic angulation, and 3) a dynamic translation plate in anterior cervical discectomy and fusion for symptomatic degenerative cervical disease. METHODS: Thirty-six patients with two level, symptomatic cervical degenerative changes requiring surgery were randomized in a blinded fashion to receive a statically locked plate, Cervical Spine Locking Plate (CSLP) (Synthes, Paoli, PN, USA), an Atlantis Vision(®) Anterior Cervical Plate System (Medtronic, Memphis, TN, USA) which allows angular dynamization, or a Premier(®) Anterior Cervical Plate System (Medtronic) which allows translational dynamization. Structured data collection and measurement protocols were used. Intervertebral composite allograft cages were used in all groups. Identical external immobilization and antiinflammatory medication protocols were followed. X-rays were obtained at preset time points postoperatively. Assessment of the primary outcomes was blinded. Rate of and time to fusion, graft/instrumentation complications, subsidence, and reoperation for adjacent level disease were measured. Paired t-test and three-way Analysis of Variance test (ANOVA) were used to assess statistical differences between groups. RESULTS: The three groups were similar demographically. Fusion rates in the CSLP, Atlantis and Premier plate groups were 100%, 91%, and 92% respectively. Mean time to fusion was 6.1, 8.3 and 6.3 months respectively but differences were not statistically significant. Mean subsidence in the groups was 1.9, 1.6, and 2.6 mm respectively. Subsidence was found even for the static (CSLP) plate, but no statistically significant differences were found. CONCLUSIONS: We found no clinical advantage of dynamic plates over static plates with regards to fusion rates, time to fusion, subsidence, complications, or adjacent-level surgery. Static plating allows for subsidence at similar levels to dynamic plating. [Table: see text] The definiton of the different classes of evidence is available on page 83.

Unstable thoracolumbar burst fractures: anterior-only versus short-segment posterior fixation.

Operative management of a thoracolumbar burst fracture varies according to many factors. Fracture morphology, neurologic status, and surgeon preference play major roles in deciding upon anterior, posterior, or combined approaches. Optimizing neural decompression while providing stable internal fixation over the least number of spinal segments is the goal. Short-segment constructs via a single-stage approach (anterior versus posterior) have become viable options with advances in instrumentation and techniques. This study compares anterior-only fixation utilizing a corpectomy strut graft and a modern thoracolumbar plating system with a posterior-only construct using pedicle screws and load sharing hooks for the treatment of unstable burst fractures. Functional outcome and sagittal plane restoration and maintenance of sagittal plane alignment were evaluated. Fifty-three patients with unstable burst fractures were assessed with 40 undergoing an anterior-only construct and 13 having a short-segment posterior-only construct. The posterior-only group had no hardware failures; however, the loss of sagittal plane correction averaged 8.1 degrees, whereas the anterior-only group averaged only a 1.8-degree increase in sagittal plane kyphosis. Both techniques resulted in statistically significant initial improvement in sagittal alignment; however, the posterior short-segment group lost this statistical significance at follow-up whereas the anterior-only group continued to demonstrate statistically significant improvement in sagittal alignment at follow-up compared to preoperative measurements.

Anterior-only stabilization of three-column thoracolumbar injuries.

OBJECTIVE: The optimal treatment of "unstable" thoracolumbar injuries remains controversial. Studies have shown the advantages of direct anterior decompression of thoracolumbar injuries along with supplemental posterior instrumentation as a combined or staged procedure. Others have also shown success in decompression as a single-stage anterior procedure, largely limited to two-column (anterior and middle) injuries. A retrospective review of all available clinical and radiographic data was used to classify unstable three-column thoracolumbar fractures according to the Association for the Study of Internal Fixation (AO) classification system. This was conducted to evaluate the efficacy of stand-alone anterior decompression and reconstruction of unstable three-column thoracolumbar injuries, utilizing current-generation anterior spinal instrumentation. METHODS: Between 1992 and 1998, 40 patients underwent anterior decompression and two-segment anteriorly instrumented reconstruction for three-column thoracolumbar fractures. Retrospective review of all available clinical and radiographic data was used to classify these unstable injuries according to the AO classification system, evaluating for neurologic changes, spinal canal compromise, preoperative and postoperative segmental angulation, and arthrodesis rate. RESULTS: According to the AO classification system, there were 24 (60%) type B1.2, 10 (25%) type B2.3, 5 (12.5%) type C1.3, and 1 (2.5%) type C2.1 three-column injuries. Preoperative canal compromise averaged 68.5% and vertebral height loss averaged 44.5%. There were no cases of neurologic deterioration, and 30 (91%) patients with incomplete neurologic deficits improved by at least one modified Frankel grade. Mean preoperative segmental kyphosis of 22.7 degrees was improved to an early mean of 7.4 degrees (P < 0.0001). At latest follow-up, angulation had increased by an average 2.1 degrees but maintained significant improvement from preoperative measurements (P < 0.0001). There was one early construct failure due to technical error. Thirty-seven of the remaining patients (95%) went on to apparently stable arthrodesis. CONCLUSIONS: Current types of anterior spinal instrumentation and reconstruction techniques can allow some types of unstable three-column thoracolumbar injuries to be treated in an anterior stand-alone fashion. This allows direct anterior decompression of neural elements, improvement in segmental angulation, and acceptable rates of arthrodesis without the need for supplemental posterior instrumentation.

Cervical spine and spinal cord injuries: recognition and treatment.

Cervical spine injuries are frequently encountered in any practice treating patients in the emergency department or outpatient trauma victims. When upper or lower cervical spine injuries are suspected, immediate immobilization, physical and neurologic examination, and radiographic evaluation are imperative. For spinal cord injuries, knowledge of microscopic and cellular pathology helps to determine appropriate management.

Two-year fusion rate equivalency between Grafton DBM gel and autograft in posterolateral spine fusion: a prospective controlled trial employing a side-by-side comparison in the same patient.

STUDY DESIGN: Multicenter, prospective equivalency trial with each patient serving as his/her own control. OBJECTIVES: To compare the effectiveness of a Grafton DBM gel composite with iliac crest autograft in posterolateral spine fusion. SUMMARY OF BACKGROUND DATA: While autograft remains the preferred graft material to facilitate spine fusion, the supply is limited and harvesting produces undesirable clinical consequences. METHODS: A total of 120 patients underwent posterolateral spine fusion with pedicle screw fixation and bone grafting. Iliac crest autograft was implanted on one side of the spine and a Grafton DBM/autograft composite was implanted on the contralateral side in the same patient. An independent, blinded reviewer evaluated anteroposterior and lateral flexion-extension radiographs. The fusion mass lateral to the instrumentation on each side was judged fused or not, and the mineralization of the graft was rated absent, mild, moderate, or extensive. The degree of correspondence in outcomes between sides was estimated by computing the percentage agreement and kappa statistic. RESULTS: Nearly 70% of patients (81 of 120) provided complete 24-month radiographic studies. The bone graft mass was fused in 42 cases (52%) on the Grafton DBMside and in 44 cases (54%) on the autograft side. The overall percentage agreement for fusion status between sides was approximately 75% (61 of 81), indicating moderately strong statistical correspondence (kappa = 0.51, P < 0.0001). Bone mineralization ratings also were similar between treated sides. Perfect agreement was realized in almost 60% of patients (48 of 81) with moderate statistical correspondence (weighted kappa = 0.54, P < 0.0001). CONCLUSIONS: Grafton DBM can extend a smaller quantity of autograft than is normally required to achieve a solid spinal arthrodesis. Consequently, a reduced amount of harvested autograft may be required, potentially diminishing the risk and severity of donor site complications.