John A. Bendo

Results of the prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of the ProDisc-L total disc replacement versus circumferential fusion for the treatment of 1-level degenerative disc disease.

Study Design. A prospective, randomized, multicenter, Food and Drug Administration-regulated Investigational Device Exemption clinical trial. Objective. To evaluate the safety and effectiveness of the ProDisc®-L (Synthes Spine, West Chester, PA) lumbar total disc replacement compared to circumferential spinal fusion for the treatment of discogenic pain at 1 vertebral level between L3 and S1. Summary of Background Data. As part of the Investigational Device Exemption clinical trial, favorable single center results of lumbar total disc replacement with the ProDisc®-L have been reported previously. Methods. Two hundred eighty-six (286) patients were treated on protocol. Patients were evaluated before and after surgery, at 6 weeks, 3, 6, 12, 18, and 24 months. Evaluation at each visit included patient self-assessments, physical and neurologic examinations, and radiographic evaluation. Results. Safety of ProDisc®-L implantation was demonstrated with 0% major complications. At 24 months, 91.8% of investigational and 84.5% of control patients reported improvement in the Oswestry Low Back Pain Disability Questionnaire (Oswestry Disability Index [ODI]) from preoperative levels, and 77.2% of investigational and 64.8% of control patients met the ≥15% Oswestry Disability Index improvement criteria. Overall neurologic success in the investigational group was superior to the control group (91.2% investigational and 81.4% control; P = 0.0341). At 6 weeks and 3 months follow-up time points, the ProDisc®-L patients recorded SF-36 Health Survey scores significantly higher than the control group (P = 0.018, P = 0.0036, respectively). The visual analog scale pain assessment showed statistically significant improvement from preoperative levels regardless of treatment (P < 0.0001). Visual analog scale patient satisfaction at 24 months showed a statistically significant difference favoring investigational patients over the control group (P = 0.015). Radiographic range of motion was maintained within a normal functional range in 93.7% of investigational patients and averaged 7.7°. Conclusions. ProDisc®-L has been found to be safe and efficacious. In properly chosen patients, ProDisc®-L has been shown to be superior to circumferential fusion by multiple clinical criteria.

Vertebral artery injury in cervical spine surgery: anatomical considerations, management, and preventive measures

BACKGROUND CONTEXT Vertebral artery (VA) injury can be a catastrophic iatrogenic complication of cervical spine surgery. Although the incidence is rare, it has serious consequences including fistulas, pseudoaneurysm, cerebral ischemia, and death. It is therefore imperative to be familiar with the anatomy and the instrumentation techniques when performing anterior or posterior cervical spine surgeries. PURPOSE To provide a review of VA injury during common anterior and posterior cervical spine procedures with an evaluation of the surgical anatomy, management, and prevention of this injury. STUDY DESIGN Comprehensive literature review. METHODS A systematic review of Medline for articles related to VA injury in cervical spine surgery was conducted up to and including journal articles published in 2007. The literature was then reviewed and summarized. RESULTS Overall, the risk of VA injury during cervical spine surgery is low. In anterior cervical procedures, lateral dissection puts the VA at the most risk, so sound anatomical knowledge and constant reference to the midline are mandatory during dissection. With the development and rise in popularity of posterior cervical stabilization and instrumentation, recognition of the dangers of posterior drilling and insertion of transarticular screws and pedicle screws is important. Anomalous vertebral anatomy increases the risk of injury and preoperative magnetic resonance imaging and/or computed tomography (CT) scans should be carefully reviewed. When the VA is injured, steps should be taken to control local bleeding. Permanent occlusion or ligation should only be attempted if it is known that the contralateral VA is capable of providing adequate collateral circulation. With the advent of endovascular repair, this treatment option can be considered when a VA injury is encountered. CONCLUSIONS VA injury during cervical spine surgery is a rare but serious complication. It can be prevented by careful review of preoperative imaging studies, having a sound anatomical knowledge and paying attention to surgical landmarks intraoperatively. When a VA injury occurs, prompt recognition and management are important.

Systematic Review of Cohort Studies Comparing Surgical Treatments for Cervical Spondylotic Myelopathy

Study Design. Systematic review of cohort studies comparing surgical treatment options for cervical spondylotic myelopathy. Objective. Compare results of major surgical treatments. Summary of Background Data. Controversy exists between various surgical options for the treatment of multilevel cervical spondylotic myelopathy, including multilevel corpectomy (CORP) and fusion, anterior cervical discectomy and fusion, laminoplasty (LAMP), and laminectomy and fusion (LAMI). A systematic review was done in order to compare results and complications among these procedures. Methods. Systematic review of retrospective cohort studies comparing anterior cervical discectomy and fusion (ACDF), CORP, LAMP, and LAMI from 1980 to January 2008. Separately, a review was performed of case series with greater than 10-year follow-up. Results. About 1735 articles found initially, 591 abstracts screened, 36 articles retrieved in full, 11 studies included in review. All comparison studies are retrospective cohort studies. Four studies compared multilevel CORP versus LAMP, 1 study compared LAMI with LAMP, and 2 studies compared ACDF with LAMP. There were 3 case studies with greater than 10-year follow-up. Conclusion. All approaches yield similar neuro recovery rates. Laminoplasty has a significant incidence of neck pain compared with multilevel CORP. ACDFs increase the rate of adjacent secondary spondylosis compared with LAMP. Multilevel CORP and laminectomy with fusion have a significantly higher rate of graft, instrumentation, and approach related complications. Multilevel CORP and laminectomy with fusion have a significant decrease in range of motion of neck compared with LAMP.

Comparative charge analysis of one- and two-level lumbar total disc arthroplasty versus circumferential lumbar fusion.

Study Design. This is a retrospective, independent study comparing 2 groups of patients treated surgically for discogenic low back pain associated with degenerative disc disease (DDD) in the lumbosacral spine. Objective. To compare the surgical and hospitalization charges associated with 1- and 2-level lumbar total disc replacement and circumferential lumbar fusion. Summary of Background Data. Reported series of lumbar total disc replacement have been favorable. However, economic aspects of lumbar total disc replacement (TDR) have not been published or studied. This information is important considering the recent widespread utilization of new technologies. Recent studies have demonstrated comparable short-term clinical results between TDR and lumbar fusion recipients. Relative charges may be another important indicator of the most appropriate procedure. We report a hospital charge-analysis comparing ProDisc lumbar disc replacement with circumferential fusion for discogenic low back pain. Methods. In a cohort of 53 prospectively selected patients with severe, disabling back pain and lumbar disc degeneration, 36 received Synthes ProDisc TDR and 17 underwent circumferential fusion for 1- and 2-level degenerative disc disease between L3 and S1. Randomization was performed using a 2-to-1 ratio of ProDisc recipients to control spinal fusion recipients. Charge comparisons, including operating room charges, inpatient hospital charges, and implant charges, were made from hospital records using inflation-corrected 2006 U.S. dollars. Operating room times, estimated blood loss, and length of stay were obtained from hospital records as well. Surgeon and anesthesiologist fees were, for the purposes of comparison, based on Medicare reimbursement rates. Statistical analysis was performed using a 2-tailed Student t test. Results. For patients with 1-level disease, significant differences were noted between the TDR and fusion control group. The mean total charge for the TDR group was

The lumbar facet joint: a review of current knowledge: part 1: anatomy, biomechanics, and grading

35,592 versus

Lumbar intervertebral disc cyst as a cause of radiculopathy.

46,280 for the fusion group (P = 0.0018). Operating room charges were

Perioperative outcomes of anterior lumbar surgery in obese versus non-obese patients

12,000 and

Somatosensory evoked potential monitoring of lumbar pedicle screw placement for in situ posterior spinal fusion

18,950, respectively, for the TDR and fusion groups (P < 0.05). Implant charges averaged

Iatrogenic spondylolysis leading to contralateral pedicular stress fracture and unstable spondylolisthesis : A case report

13,990 for the fusion group, which is slightly higher than the

The lumbar facet joint: a review of current knowledge: Part II: diagnosis and management

13,800 for the ProDisc (P = 0.9). Estimated blood loss averaged 794 mL in the fusion group versus 412 mL in the TDR group (P = 0.0058). Mean OR minutes averaged 344 minutes for the fusion group and 185 minutes for the TDR (P < 0.05) Mean length of stay was 4.78 days for fusion versus 4.32 days for TDR (P = 0.394). For patients with 2-level disease, charges were similar between the TDR and fusion groups. The mean total charge for the 2-level TDR group was