Your Artificial Disc Replacement & "General" Spine Questions Answered Here!

[Justin]

Dear Spine Patients:

The Spine Patient Society™ will be more than willing to answer your questions regarding
Artificial Disc Replacement (ADR) surgery and will provide you with any resources you may need including, but not limited to:

• Publications & Educational Materials

• Spine Patient references that are willing to share their personal experience with ADR.

• Manufacturer & Device Company Contacts

• "General" Information Regarding Artificial Disc Replacement

• Physician Locators & Insurance Guidance

• Plus, any ADR-related questions that are relevant to the Spine Patient community.

Questions can be posted directly in this thread by clicking "Add New Post" or feel free to email your questions to the Spine Patient Society™:

justin @ spinepatientsociety.org

Hopefully, this project will help many patients just like you!

*The Spine Patient Society does not provide medical advice and is not intended to substitute as medical advice. Please seek the help of a trained medical professional. For more information, see the Spine Patient Society's Terms of Service.

[Justin]

Katie, ADR is the only surgery I have ever had. I don't have a clue what they do with the organs during ADR, Justin?

Kathy, I'd be glad to fill you in about the surgical approach to the anterior lumbar region. This approach is used for both discectomy, or removal of a disc, and implantation of any instrumentation.

The access surgeon will either choose between two approaches: a midline rectus approach or a paramedian lateral rectus approach. The "rectus" is from the muscle rectus abdominis, commonly known as your abdominals. The approach sometimes depends on access surgeon preference and the vertebral level operated on.

Your abdominal organs are contained in a sac-like structure called the peritoneum. This "sac" contains your stomach, most of the small intestine, the transverse section of your colon, liver and gallbladder. Mesentery, which is a small fold of tissue, helps anchor these organs to the abdominal wall so that all these organs don't just "sink" to the bottom of the sac, or peritoneum.

The structures not contained in the peritoneal cavity are called "retroperitoneal"--these include the aorta, inferior vena cava, kidneys and your suprarenal glands.

I hope that makes sense so far.

OK, so what do they do with this peritoneal "sac" full of organs you ask? Well...once they have the rectus muscle freely mobile, the muscle is moved and held out of the way by a retractor (the muscle is now said to be "retracted"). The inner abdominal muscles are "blunt finger dissected" to keep the abdominal approach "muscle sparing"--without division of the abdominal muscles. The peritoneum, containing the organs listed above, is moved out of the way the by access surgeon. Essentially, the peritoneum is carefully pushed / manipulated out of the way by the access surgeon (bowel cleanse, anyone? ) and more retractors are placed "to keep things out of the way."

Next, the surgeon makes every effort to identify the genito-femoral nerve (which lies over the psoas muscle) & the ureter (which carries urine made in the kidneys to the bladder), to protect them from injury. At this point, the surgeon should easily be able to feel the vertebral column and the great vessels that lie in front of it (the aorta [carries oxygenated blood away from the left heart and to the rest of the body] and the inferior vena cava [returns deoxygenated blood from the body to the right side of the heart]). These vessels are subsequently moved--retracted out of the way--so the surgeon can see the disc space.

OK, I am greatly simplfiying a lot of this, as other smaller structures have to be addressed as well (different nerve plexus, smaller vessels, etc.).

Kathy, does this make sense that the abdominal organs just don't "pop out" when they open you up?

I hope this helps.

[Katie]

Justin, thanks SO much for explaining that! I have been floundering for the correct words and descriptions of the anatomy so many times. I took health sciences at University but it was decades ago, and most days I can't remember what I had for breakfast

I can just picture the process in my mind as you were describing it. Great job!

[Justin]

Justin, thanks SO much for explaining that! I have been floundering for the correct words and descriptions of the anatomy so many times. I took health sciences at University but it was decades ago, and most days I can't remember what I had for breakfast

I can just picture the process in my mind as you were describing it. Great job!

No problem, Katie. Thanks for your kind words.

[Justin]

Bob measured me last night, and I am now 5'4". All my adult life I have been 5'3.5", but at my last physical just a couple months before surgery I was measured to be 5'3". So, a half inch taller than my normal height and a full inch taller than pre-op.

That's great! I remember growing an inch after my 2-level Artificial Disc Replacement--I felt like a baby learning to walk for the first time during my first stroll through the hospital. It was surreal.

Justin, I guess I am doing all right with distraction pain. In fact the only "pain" I feel has been this aching in my legs. I don't know if that is distraction pain or??? The brace pokes into my butt when I am sitting down, and if I am sitting too long with the brace on I have to loosen it up a little as I start to feel like it is restricting my breathing (particularly when in a car).

The distraction pain for me was more of an "ache," but it was constant. I felt as if I could not get comfortable no matter what I did for a good amount of time. I agree about the brace--make sure to adjust it often, as it can get too tight.

How is distraction pain described? This is the pain that is caused by the change in disc height and spine alignment, is that right? I think I had some of that the first week after surgery, but I haven't really been feeling that lately.

Alastair sent me this excerpt on distraction pain some time ago and I believe it is a very good one:

In the context of ADR surgery the word distraction refers to the action of mechanically increasing the distance between adjacent vertebral endplates in order to accomplish the removal of disc material and insertion of an artificial disc. The result of distraction is a stretching of tissues (muscle, ligament, nerve, blood vessel) in the vicinity. This stretching, which is beyond what is normally experienced by the body, causes what has been referred to as 'distraction pain'.

The "pain" from distracting the disc space in an effort to ultimately restore the intervertebral disc height and permit the insertion of an Artificial Disc comes from the stretching of associated structures listed above. Nerves are very sensitive to any manipulation and the act of stretching them to a new length or altering their previous alignment can lead to significant pain / aching / burning sensations in one's legs and feet. This overall feeling of being uncomfortable is usually not relieved by massage, rest or stretching and takes time for the irritation of structures to subside before one feels relief. Distraction pain is very unique from person to person and depends on a lot of factors (duration of injury before surgery, the number of levels treated, weight, surgically-induced trauma, etc.) that are inherently unique to one's individual situation.

I hope this helps.

[Katie]

Justin, this is exactly what we are needing! Precise answers to our questions, put in one spot that we can use for reference at any time. It will save so much time and energy, instead of hunting and pecking through our memory or some long lost 'bookmarked' site.

Many thanks, kind sir

[Justin]

There is a great publication on instability and spinal fusion: Emedicine, Spinal Instability and Spinal Fusion Surgery, Author: Peyman Pakzaban, MD, Consulting Neurosurgeon, Houston MicroNeurosurgery; Chairman, Department of Surgery, Patients Medical Center (Link). Here are some excerpts quoted below:

In their widely-quoted work, White and Panjabi defined spinal stability as the ability of the spine under physiological loads to limit patterns of displacement so as to not damage or irritate the spinal cord and nerve roots and, in addition, to prevent incapacitating deformity or pain due to structural changes.2 Conversely, instability refers to excessive displacement of the spine that would result in neurological deficit, deformity, or pain. Instability can be acute (eg, spine fractures and dislocations) or chronic (eg, spondylolisthesis). Acute instability has been further subcategorized as overt versus limited, whereas chronic instability has been subdivided to include glacial instability (progressive deformity) and instability associated with dysfunctional motion segment.3

A simpler conceptual approach would be to think of instability as overt, anticipated, or covert.

Overt instability refers to excessive motion that is readily documented by radiographic studies and results in pain, deformity, or neurological deficit. Those spine fractures, dislocations, tumors, and infectious processes that significantly disrupt one or more spinal motion segments produce acute overt instability. Spondylolisthesis with abnormal dynamic displacement, documented on flexion/extension x-ray films, is an example of chronic overt instability. In addition, any spinal deformity (kyphosis, hyperlordosis, scoliosis, or spondylolisthesis) that progresses with time as documented by serial radiographs (ie, Benzel glacial instability) falls in the category of chronic overt instability. Overt instability generally requires stabilization, either by external means (bracing) or internal means (fusion).

Anticipated instability refers to instability that would be produced by a surgical procedure that is required for proper decompression of neural elements or resection of an offending lesion. For instance, corpectomy or total facetectomy would constitute indications for fusion at the time of the original operation. A comprehensive anterior cervical discectomy (with complete resection of the posterior longitudinal ligament and portions of both uncovertebral joints performed for adequate neural decompression) may also be considered in this category, as its disrupts 2 of Denis' 3 spinal columns.

Covert instability is a more elusive concept. It refers to circumstances in which excessive motion cannot be grossly demonstrated but is presumed to exist based on the combination of clinical and radiographic findings. Fixed spondylolisthesis (without movement on flexion and extension x-ray films) in the setting of progressively worsening back pain and/or radicular symptoms is a good example of covert instability. Pseudarthrosis with intact instrumentation also falls in this category. Controversy arises when the concept of covert instability is applied to degenerative diseases of the spine. In this context, the concept of micro-instability is sometimes evoked to justify fusion for a wider range of conditions, including recurrent disc herniation, disc degeneration with discogenic pain, painful facet arthropathy, spinal stenosis, and failed back syndrome without overt instability.

Kirkaldy-Willis provided a classification of degeneration of the spine based on 3 phases that inherently included spine instability:

The first phase, Phase I, is known as the Dysfunctional Phase. This phase is characterized by circumferential tears or fissures in the outer annulus. In addition, endplate separation or failure can disrupt the blood supply, resulting in the loss of nutrition to the disc. These changes are thought to result from repetitive microtrauma. One hypothesis is that the discs' nuclear proteoglycans lose the capacity to absorb water and maintain their protective function. Low back pain, low grade disc degeneration and laxity of the facet capsule is included in this phase.

Phase II, or the Unstable / Instability Phase, is characterized by multiple annular tears (both radial and circumferential), internal disc disruption, and resorption or loss of disc space height. This phase is thought to result from the progressive loss of the mechanical integrity of the 3-joint complex. Increased facet joint laxity and moderate disc degeneration is present.

Phase III is also known as the Stabilization / Restabilization Phase. Further disc resorption, disc space narrowing, endplate destruction, disc fibrosis, and osteophyte formation are present leading to decreased overall motion. Disc injuries are more likely to occur in phase I or II of the degenerative process. Disc degeneration has reached final stage (grades 3 to 4).

Source: Kirkaldy-Willis WH, ed. The pathology and pathogenesis of low back pain. Managing Low Back Pain. New York, NY: Churchill Livingstone; 1988:49.

I hope this helps.

[KBear]

Thanks, this is just in time. I had some weird burning sensations in my foot for the first time the other day. I thought maybe I did something wrong and screwed my spine up! (so like me to jump to the worst case scenario). I'm glad to know this is 'distraction pain' and normal.

[Justin]

Thanks, this is just in time. I had some weird burning sensations in my foot for the first time the other day. I thought maybe I did something wrong and screwed my spine up! (so like me to jump to the worst case scenario). I'm glad to know this is 'distraction pain' and normal.

No problem. There are many weird sensations and aches & pains that occur post-op. A lot of these symptoms don't present right after surgery, so many patients often think they've done something to jeopardize their recovery--like you mentioned. Unfortunately, recovery is a roller coaster; however, the majority of patients really start to turn the corner about 3 to 6 months post-op.

[KanRunMo]

Are there any cost comparisons of ADR or other spine treatments? Total cost and cost with insurance?