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The total posterior spine or TOPS system is an FDA-approved mechanical implant that serves as an alternative to lumbar interbody fusion surgery after decompression. It was developed by Impliant and commercially launched by Premia Spine. [1] [2]
The TOPS System offers new methods for the non-fusion treatment of degenerative spondylolisthesis and spinal stenosis. [3]
It treats patients diagnosed with common degenerative spinal diseases such as lumbar spinal stenosis, which occurs when the small joints between the vertebrae compress the spinal nerve roots in the lower back and Grade 1 spondylolisthesis occurs when one vertebra "slips" over the one below it. One of the differences between the TOPS System and traditional fusion surgery is that the TOPS device allows the patient physical stability and a greater range of movement in all directions. [4] [5]
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The TOPS System is a unitary implant composed of two titanium plates connected by an interlocking flexible articulating core. It has metal arms connecting horizontally to pedicles with four polyaxial screws. The device can be implanted after a standard decompression by removing the lamina and medial facets in a "posterior arthroplasty" procedure. [6] The TOPS System replaces the bony and soft tissue removed during spinal decompression surgery and implants them at the affected spine segment to aid the patient's flexibility. [7]
Premia Spine developed the TOPS System and initiated a US trial to compare it with the traditional transforaminal lumbar interbody fusion (TLIF) procedure. Results showed that the TOPS System offers significant clinical, health, and societal benefits over TLIF. Under the Investigational Device Exemption (IDE) study by the FDA, the system was available to a limited number of U.S. patients at select hospitals and institutions. [8]
In March 2021, the U.S. Food and Drug Administration (FDA) granted a “breakthrough device designation” (FDA’s initiative for medical devices that significantly improve treatment of severe or debilitating conditions) to the TOPS System. [9] [10]
In 2023, the U.S. Food and Drug Administration approved the TOPS System as an implant designed to stabilize the lower spine and maintain the range of motion after surgery to relieve compressed nerves (lumbar decompression surgery). [11]
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Studies highlighted its ability to preserve spine biomechanics, measuring effects on disc strain and bulge. Pain and quality of life improvements were quantitatively assessed using the Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and Short Form 36 (SF-36). X-rays, CT scans, and MRIs were used to monitor the implant for adverse events or changes. [12] [6]
A 2012 study presented in Barcelona found that one in four elderly patients who had lumbar spinal fusion for lumbar spinal stenosis (LSS) or spondylolisthesis needed a second spinal surgery within two years. Additionally, nearly half of these patients were readmitted to the hospital due to complications. Comparatively, Premia Spine's follow-ups over five years in Belgium and Israel suggest that the TOPS System yields significantly better outcomes, with a preoperative complication rate under five percent. [13] [14] [15] [16]
In March 2021, Premia Spine received FDA breakthrough device designation for its Tops facet arthroplasty system. [17]
In July 2021, Jared Ament presented the clinical and economic evidence supporting the TOPS facet arthroplasty system at the Spine Summit, San Diego, demonstrating its cost-effectiveness compared to TLIF for treating spondylolisthesis and spinal stenosis. [18] [19] [20]
In November 2021, its intermediate clinical study results, presented at the Society for Minimally Invasive Spine Surgery (SMISS) supported the use of the TOPS System for lumbar spinal stenosis and degenerative spondylolisthesis. [21] [22]
In June 2022, a study published in the Journal of Health Economics and Outcomes Research demonstrated that the TOPS System offers significant health and societal benefits compared to TLIF in treating degenerative spondylolisthesis and stenosis. [8] [23] [24] [25]
In September 2022, the journal Operative Neurosurgery published a single-center study evaluating its TOPS System for lumbar spinal stenosis and degenerative spondylolisthesis. [26] The paper "Mobility-Maintaining Arthroplasty of the Lumbar Spine with the Second-Generation TOPS System" by Werner Lack, Hans Paul Kutschera, and Josef Krugluge found that the TOPS facet replacement can relieve leg and back pain while maintaining nearly normal range-of-motion for four years without causing adjacent segment disease. The study also noted that the TOPS System uniquely helps patients maintain natural sagittal balance, offering new options for non-fusion treatment of degenerative spondylolisthesis and spinal stenosis. [27]
Premia Spine received FDA approval to start an IDE trial of the TOPS System with 300 to 500 patients across up to 40 U.S. centers, randomizing participants into TOPS (67%) or fusion (33%) arms. The trial aims to compare the efficacy of TOPS versus TLIF in stabilizing one lumbar level (L2-L5) after decompression in patients with moderate lumbar spinal stenosis and Grade 1 spondylolisthesis, including conditions like thickened ligamentum flavum or scarred facet joints. [28]
In September 2022, Dr. Dom Coric and colleagues published a study in the Journal of Neurosurgery Spine, which demonstrated that the TOPS System, a motion-preserving treatment for lumbar stenosis with degenerative spondylolisthesis, outperformed TLIF in clinical success rates. [29] [30]
The FDA concluded, as part of its PMA approval process and commercial release of the TOPS System, that the TOPS group demonstrated a clinically meaningful and substantial advantage over the Fusion control group, with 77% of subjects randomized to the TOPs group achieving composite clinical success, compared to 24% of subjects randomized to the fusion control. Based on these results, the TOPS System was deemed to be superior to the Fusion control with respect to composite clinical success while maintaining equivalent safety. [31]
Lumbar spinal stenosis (LSS) is a medical condition in which the spinal canal narrows and compresses the nerves and blood vessels at the level of the lumbar vertebrae. Spinal stenosis may also affect the cervical or thoracic region, in which case it is known as cervical spinal stenosis or thoracic spinal stenosis. Lumbar spinal stenosis can cause pain in the low back or buttocks, abnormal sensations, and the absence of sensation (numbness) in the legs, thighs, feet, or buttocks, or loss of bladder and bowel control.
A laminectomy is a surgical procedure that removes a portion of a vertebra called the lamina, which is the roof of the spinal canal. It is a major spine operation with residual scar tissue and may result in postlaminectomy syndrome. Depending on the problem, more conservative treatments may be viable.
Spondylosis is the degeneration of the vertebral column from any cause. In the more narrow sense it refers to spinal osteoarthritis, the age-related degeneration of the spinal column, which is the most common cause of spondylosis. The degenerative process in osteoarthritis chiefly affects the vertebral bodies, the neural foramina and the facet joints. If severe, it may cause pressure on the spinal cord or nerve roots with subsequent sensory or motor disturbances, such as pain, paresthesia, imbalance, and muscle weakness in the limbs.
Degenerative disc disease (DDD) is a medical condition typically brought on by the normal aging process in which there are anatomic changes and possibly a loss of function of one or more intervertebral discs of the spine. DDD can take place with or without symptoms, but is typically identified once symptoms arise. The root cause is thought to be loss of soluble proteins within the fluid contained in the disc with resultant reduction of the oncotic pressure, which in turn causes loss of fluid volume. Normal downward forces cause the affected disc to lose height, and the distance between vertebrae is reduced. The anulus fibrosus, the tough outer layers of a disc, also weakens. This loss of height causes laxity of the longitudinal ligaments, which may allow anterior, posterior, or lateral shifting of the vertebral bodies, causing facet joint malalignment and arthritis; scoliosis; cervical hyperlordosis; thoracic hyperkyphosis; lumbar hyperlordosis; narrowing of the space available for the spinal tract within the vertebra ; or narrowing of the space through which a spinal nerve exits with resultant inflammation and impingement of a spinal nerve, causing a radiculopathy.
Spondylolisthesis is the displacement of one spinal vertebra compared to another. While some medical dictionaries define spondylolisthesis specifically as the forward or anterior displacement of a vertebra over the vertebra inferior to it, it is often defined in medical textbooks as displacement in any direction. Spondylolisthesis is graded based upon the degree of slippage of one vertebral body relative to the subsequent adjacent vertebral body. Spondylolisthesis is classified as one of the six major etiologies: degenerative, traumatic, dysplastic, isthmic, pathologic, or post-surgical. Spondylolisthesis most commonly occurs in the lumbar spine, primarily at the L5-S1 level, with the L5 vertebral body anteriorly translating over the S1 vertebral body.
Cauda equina syndrome (CES) is a condition that occurs when the bundle of nerves below the end of the spinal cord known as the cauda equina is damaged. Signs and symptoms include low back pain, pain that radiates down the leg, numbness around the anus, and loss of bowel or bladder control. Onset may be rapid or gradual.
Spinal fusion, also called spondylodesis or spondylosyndesis, is a surgery performed by orthopaedic surgeons or neurosurgeons that joins two or more vertebrae. This procedure can be performed at any level in the spine and prevents any movement between the fused vertebrae. There are many types of spinal fusion and each technique involves using bone grafting—either from the patient (autograft), donor (allograft), or artificial bone substitutes—to help the bones heal together. Additional hardware is often used to hold the bones in place while the graft fuses the two vertebrae together. The placement of hardware can be guided by fluoroscopy, navigation systems, or robotics.
Failed back syndrome or post-laminectomy syndrome is a condition characterized by chronic pain following back surgeries. Many factors can contribute to the onset or development of FBS, including residual or recurrent spinal disc herniation, persistent post-operative pressure on a spinal nerve, altered joint mobility, joint hypermobility with instability, scar tissue (fibrosis), depression, anxiety, sleeplessness, spinal muscular deconditioning and even Cutibacterium acnes infection. An individual may be predisposed to the development of FBS due to systemic disorders such as diabetes, autoimmune disease and peripheral blood vessels (vascular) disease.
A spinal disc herniation is an injury to the intervertebral disc between two spinal vertebrae, usually caused by excessive strain or trauma to the spine. It may result in back pain, pain or sensation in different parts of the body, and physical disability. The most conclusive diagnostic tool for disc herniation is MRI, and treatment may range from painkillers to surgery. Protection from disc herniation is best provided by core strength and an awareness of body mechanics including good posture.
Jack Elliot Zigler is a Board Certified orthopedic surgeon specializing in spine surgery at the Texas Back Institute in Plano, Texas. He is best known for being the first surgeon to perform a ProDisc artificial disc replacement surgery in the United States, on October 3, 2001.
An artificial facet replacement is a joint prosthesis intended to replace the natural facets and other posterior elements of the spine, restoring normal motion while providing stabilization of spinal segments. It is typically used as an adjunct to laminectomy, laminotomy, neural decompression, and facetectomy, in lieu of standard lumbar fusion. The prosthesis is indicated for back and leg pain caused by central or lateral spinal stenosis, degenerative disease of the facets with instability, and grade 1 degenerative spondylolisthesis with objective evidence of neurological impairment.
Neurogenic claudication (NC), also known as pseudoclaudication, is the most common symptom of lumbar spinal stenosis (LSS) and describes intermittent leg pain from impingement of the nerves emanating from the spinal cord. Neurogenic means that the problem originates within the nervous system. Claudication, from the Latin word for to limp, refers to painful cramping or weakness in the legs. NC should therefore be distinguished from vascular claudication, which stems from a circulatory problem rather than a neural one.
A laminotomy is an orthopaedic neurosurgical procedure that removes part of the lamina of a vertebral arch in order to relieve pressure in the vertebral canal. A laminotomy is less invasive than conventional vertebral column surgery techniques, such as laminectomy because it leaves more ligaments and muscles attached to the spinous process intact and it requires removing less bone from the vertebra. As a result, laminotomies typically have a faster recovery time and result in fewer postoperative complications. Nevertheless, possible risks can occur during or after the procedure like infection, hematomas, and dural tears. Laminotomies are commonly performed as treatment for lumbar spinal stenosis and herniated disks. MRI and CT scans are often used pre- and post surgery to determine if the procedure was successful.
Artificial disc replacement (ADR), or total disc replacement (TDR), is a type of arthroplasty. It is a surgical procedure in which degenerated intervertebral discs in the spinal column are replaced with artificial disc implants in the lumbar (lower) or cervical (upper) spine. The procedure is used to treat chronic, severe low back pain and cervical pain resulting from degenerative disc disease. Disc replacement is also an alternative intervention for symptomatic disc herniation with associated arm and hand, or leg symptoms.
Spinal disease refers to a condition impairing the backbone. These include various diseases of the back or spine ("dorso-"), such as kyphosis. Dorsalgia refers to back pain. Some other spinal diseases include spinal muscular atrophy, ankylosing spondylitis, scoliosis, lumbar spinal stenosis, spina bifida, spinal tumors, osteoporosis and cauda equina syndrome.
Robert S. Biscup is an American orthopaedic surgeon.
An interbody fusion cage is a prosthesis used in spinal fusion procedures to maintain foraminal height and decompression. They are cylindrical or square-shaped devices, and usually threaded. There are several varieties: the Harms cage, Ray cage, Pyramesh cage, InterFix cage, and lordotic LT cage, all of which are made from titanium; the Brantigan cage, made from carbon fibre; and the Cortical Bone Dowel, which is cut from allograft femur. The cages can be packed with autologous bone material in order to promote arthrodesis. Such implants are inserted when the space between the spinal discs is distracted, such that the implant, when threaded, is compressed like a screw. Unthreaded implants, such as the Harms and Pyramesh cages have teeth along both surfaces that bite into the end plates.
Spinal stenosis is an abnormal narrowing of the spinal canal or neural foramen that results in pressure on the spinal cord or nerve roots. Symptoms may include pain, numbness, or weakness in the arms or legs. Symptoms are typically gradual in onset and improve with leaning forward. Severe symptoms may include loss of bladder control, loss of bowel control, or sexual dysfunction.
NuVasive, Inc. is a medical devices company based in San Diego, California. Founded in 1997, it primarily develops medical devices and procedures for minimally invasive spine surgery.
Hamid Reza Abbasi is an Iranian-American board-certified neurosurgeon known for his work in advanced minimally invasive spine surgery, notably the Trans-Kambin OLLIF procedure. He also serves as the Chief Medical Officer and founder of Inspired Spine.