FDA Approves Medtronic’s BRYAN® Artificial Cervical Disc for Treatment of Single-level Cervical Disc Diseases
June 30, 2009
A novel artificial cervical disc, BRYAN® developed by Medtronic, Inc. gained approval from the U.S. Food and Drug Administration (FDA) for the treatment of single-level cervical disc diseases like radiculopathy and/or myelopathy. A titanium-polyurethane device, the Bryan Cervical Disc is implanted in milled pockets of adjacent vertebral bodies from C3-C7 to substitute a diseased or bulging natural cervical disc. The disc permits flexion/extension, translation, axial rotation, and lateral bending of the cervical spine and circumvents the limitations associated with the potential alternative, anterior cervical discectomy and fusion (ACDF).
Previously, Heidecke and colleagues (Acta Neurochirurgica, 2008) reported the clinical outcome of degenerative cervical disease patients after two years of ventral discectomy and Bryan cervical disc implantation. The prospective study comprised of 54 cervical disc herniation and/or spondylosis patients with preserved mobility in the spinal segments, and clinical presentation of cervical myelopathy and/or radiculopathy with or without neck pain. Single level disc implantation was conducted in 49 patients and five patients received the implant at two adjacent levels.
After two years of implantation, dislocation or migration of the implants was not observed in any patient, and neurological outcomes based on Odom criteria were found to be good or excellent in all patients. Seven out of 59 implanted Bryan discs (12%) had loss of function with motion range of less than 3 degrees, and 17 out of 59 (29%) segments showed McAffee grades 1-4 heterotopic ossification. The researchers noted that follow-up for a longer period and comparison with a control group could aid in better understanding of the long-term benefits and potential of artificial cervical discs.
Kim et al (European Spine Journal, 2009) compared the Bryan cervical disc replacement with ACDF for radiographic outcomes such as anterior intervertebral height (AIH), functional spinal unit (FSU), overall sagittal alignment (C2-C7), posterior intervertebral height (PIH), range of motion (ROM), and radiographic changes at the implanted and adjacent levels. ACDF was conducted in 54 patients, with 26 single-level and 28 double-level procedures. Of the 105 patients included in the study, 51 were implanted with 63 Bryan discs, 39 with single-level and 12 with double-level implantation. The Bryan group was followed-up for a mean 19 months and ACDF group for mean 20 months.
Clinical improvements in terms of visual analogue scale (VAS) and neck disability index (NDI) scores at the final follow-up, compared to pre-operative scores, was observed in both the groups. Clinical outcomes at the final follow-up were not substantially different between the two groups. However, radiographic factors such as overall sagittal alignment of cervical spine, and ROM and intervertebral heights at the site of operation, certain adjacent levels and FSU were observed to be well preserved in the Bryan group in contrast to the ACDF group. ACDF surgeries demonstrated 3.5-fold higher radiological changes, emphasizing the need for longer follow-up for the assessment, in order to determine if the radiographic changes could indicate symptomatic adjacent level disease.
Cervical myelopathy, a compression of spinal cord, is usually caused due to degenerative changes in the region. Some of the major manifestations include vague sensory and motor symptoms associated with neck stiffness and pain, atrophy of upper extremity muscles, spastic gait and sphincter control problems. Another cervical disc disease, cervical radiculopathy is characterized by the experience of numbness, pain, or weakness in arm, wrist, hand, or shoulder due to injury in the cervical vertebrae or discs. Causes could be attributed to cervical disc herniation, spinal stenosis and degenerative disc disease. If the pain persists over a period of 6 to 12 weeks of conservative treatments of rest, medication and physiotherapy, surgery is an option for treatment. The recent FDA approval of the artificial cervical disc provides surgeons with a viable alternative to the ACDF, with an improved range of motion in the operated region of the neck.
About Medtronic, Inc: The Minneapolis-based medical technology company focuses on major therapies for cardiac rhythm disease management, cardiovascular disease, diabetes, neuromodulation. Following this approval, the company now offers a wide range of artificial cervical discs, which cater to requirements such as favorable implant materials, surgical procedures, fixation methods, etc.
References
1. Medtronic Receives FDA Approval for BRYAN® Cervical Disc System. Press Releases. Medtronic, Inc. Last accessed June 17, 2009.
2. Heidecke V, Burkert W, Brucke M, Rainov NG. Intervertebral disc replacement for cervical degenerative disease–clinical results and functional outcome at two years in patients implanted with the Bryan cervical disc prosthesis. Acta Neurochir (Wien). 2008 May;150(5):453-9; discussion 459.
3. Kim SW, Limson MA, Kim SB, et al. Comparison of radiographic changes after ACDF versus Bryan disc arthroplasty in single and bi-level cases. Eur Spine J. 2009 Feb;18(2):218-31.
Stay ahead of competition with MediNEWS.Direct!
To receive the latest clinical updates and health news alerts, please subscribe to our quarterly magazine in a single step by clicking here
Comments
Got something to say?
You must be logged in to post a comment.
Stay Updated Via Our Twitter Alerts
