What causes Intervertebral disc degeneration and herniation?

• The symptoms result from natural deterioration. Normally, the intervertebral disc begins to
   degenerate from the age of 25 onwards. Common among those between 30-40 years old
   and Senior patients aged over 65 years

• risk factors,
- obesity (with weight pressing on the disc all the time).
- Frequent smoking
- Prolonged period of sitting, and the frequent lowering and raising body to lift heavy items

Symptoms

•  nerve compression, causing weakness or numbness of legs. 
•  leg pain, without backache

Treatments

•  Disc degeneration or herniation does not always require surgery and not all patients have
   symptoms.

•  Balance their activities and symptoms can lead their lives with less trouble. For example, obese
   patients can stand longer if they lose weight whereas those who often lower and raise their
   body need to do so with less frequency. Patients between 60-70 years of age with such
   personal diseases as heart disease or diabetes will be less active, leading to less frequency
   of symptoms.

•  Surgery

Other causes of spinal diseases

•  Tumor - the most common type is the one that proliferates from other organs.

•  Bone erosion or fracture caused by the spreading cancer without patient’s awareness.

Whenever the cause seems unreasonable but the symptoms are serious, it means the bone in the area may have some problems, such as fracture due to a minor accident.

Criteria for making a surgery decision

Whatever types of spinal disease, there are four criteria for a doctor to consider before performing a surgery:

1)  pain;

•  the pain the patient feels depends on how much he or she can tolerate. Suppose that the pain becomes so unbearable that the patient cannot sleep or sit on a chair to work and the disease can be treated with a surgery, the patient will be so treated.

•  There are a few patients that fall into this category as in most patients the pain can be relieved without any need for an operation, but with medication, inocuation or a rest.

•  The patients in need of a surgery are those whose pain is an obstacle to their work

When the pain becomes intolerable and hinders the patient’s work, they will have a surgery. So, it is up to the patients to choose. Doctors will not anymore make a decision for them. Instead, the doctors will tell their patients that the disease can be cured with a surgery and whether to undergo the treatment depends on the patients themselves.

2)  Symptoms of damaged nerves such as muscle contractures, numbness or weakness of the patient’s leg, or more obvious symptoms;

3)  Loss of Bowel and Bladder Control in patients with damaged nerves at anal sphincter;

4)  No improvement after several methods of treatment.

When it comes to the second and third criteria, the doctors need to make a decision for the patients. For instance, some patients may insist the pain is bearable but their Muscle Contractures are obvious or they have walking difficulty. If we decide to wait any longer, their nerves will keep deteriorating. At the time when a surgery is decided, it will be too late.

What does a successful surgery depend on?

Whether a surgery is successful depends on several factors.

1.  The disease must be cured with a surgery. The area of herniation and compression must be
     clearly seen, be it by means of an x-ray, CT scan or MRI.

2.  A surgery must be appropriately performed.

3.  Third, it must be done at the right time to ensure high chance of recovery. If the treatment is
     performed too late, the patient cannot recover, but it will be unnecessary if done too early.

4.  Experienced doctors must perform the surgery. All four factors will contribute to a successful
     treatment.

•  MIS can be performed by making a small opening in order to reshape the affected bone.

•  This method is suitable for patients with less advanced symptoms who undertake a surgery
   early.

•  Spinal surgery depends on the patient’s symptom. If the symptom is not serious, a minor surgery
   will be performed.

•  Major surgery will be done in case of advanced symptom.

•  Unlike knee joint or hip surgery, there is no need to wait until the last stage of disease before
   undertaking a spinal surgery.

Trend in patients with spinal diseases

•  Recent years have seen more awareness in spinal diseases probably, more patients come
   into spotlight with less fear of surgery, visit doctors and ask for their second or third opinion.  

•  It is recommended that these patients seek the second opinion to widen their viewpoints and
   enhance their understanding that a surgery is not 100% effective and presents some risks.

 •  At present, the patients undergoing a surgery fall into two age groups: 
     1. those between 40-50 years 
     2. over 70 years.
     The latter experiences bone degeneration. In studying the possibility of surgery, we consider
     not only the patient’s age, but also their readiness and risk factors such a personal diseases.
     For instance, the 60-year-old patient with Coronary Artery Disease has higher risk than does
     the 90-year-old one with no heart disease. The method of surgery will be carefully chosen to
     suit any individual case.

 •  Apart from a surgery, we still have many other treatment options such as medication, physical
     therapy, pelvic traction and acupuncture.

 •  It may be true that a surgery is the last option, but for some diseases if we do not wait until the
     last stage, we will have more treatment options. However, if we wait until the advanced stage,
     the surgery will become more invasive and requires a lot more to work on due to more
     symptoms. Consequently, if there is such prior intervention, the patient’s symptoms can be
     relieved without any need to depend on surgery as a last resort.

What is Total Artificial Disc Replacement

Total Artificial Disc Replacement is the latest world innovation and technology which is an alternative surgical treatment in patients with chronic back pain caused by Degenerative Disc Disease (DDD) to have a chance to return to symptom-free permanently.  Degenerative Disc Disease results in flattening disc space, losing its normal height. This height is important as it separates the disc above from the one below. When disc height is lost, the nerve root pathways may become narrow and result in nerve impingement, inflammation, and pain. It can occur at any spinal levels although it is very common in the lumbar region. Severity of back pain does not depend only on the pathology caused by the disc shape, but the patient’s age or traumatic disc condition and other various factors are also concerned.

How does Total Artificial Disc prosthesis help?

Total artificial disc prosthesis is intended to maintain the normal movement between two vertebral bodies and prevents them from collapsing (and thereby irritating or damaging the nerve roots) by maintaining the disc space height between both bony surfaces. It leads to restoration of spinal stability similar to the beneficial effect of total knee or hip replacement. Patients who suffer with chronic low back pain caused by DDD, could have their chance to return to symptom-free-normal life again. In addition, total disc replacement theoretically protects the discs at the adjacent levels by sharing or distributing the stress through the lower back during normal activities such as lifting and bending (flexion and extension).

The advantages of the Total Artificial Disc Replacement

1. Restoration of spinal stability
2. Restoration of nearly-normal physiologic mobility of spine
3. Restoration of normal disc space height

The successful outcome of Total Artificial Disc Replacement is based on two factors

1. Appropriate patient selection with a clear diagnosis and indication for surgery
2. Spine surgeons who are specially-trained or highly-experience  in  anterior spinal approach
    to the spine

Spinal Fusion (usual standard method in spinal surgery)

Conservative treatment of Degenerative Disc Disease (DDD) is usually effective in patients with early stage of back pain and resulted in a short-term remittance. But in some of individuals who still suffer from chronic low back pain ,as the degenerated disc, the etiology, is still remaining and interfering with their working abilities and  activities of daily living, the surgical treatment may finally become necessary. Lumbar spinal fusion or arthrodesis, a usual standard surgical treatment in DDD, is consisted of removing the disc tissue and fusing both two vertebrae together with bone graft and sometimes supplemented with pedicle screw fixation. Patients usually return to symptom-free of back pain after fusion but lose their abilities to move in the “fused”segment and the recovery period after fusion varies individually, usually about 3-4 months post operation. Failure of the fusion may be associated with continuation of symptoms. Spinal fusion in one or more levels will create some stiffness and decrease motion of the spine, cause more stress at its adjacent levels. This problem with the transferred stress in the adjacent levels may increase the risk of further degeneration of the adjacent discs which may also lead to additional back surgery.

Post-operative care for Total Artificial Disc Replacement (TADR)

Comparison of Total Artificial Disc Replacement and Standard Spinal Fusion

	Fusion	TADR
1. Size of incision	10-15 cm.	5-8 cm.
2. Position of incision	Back	Front (nearby navel)
3. Operative duration	2-4 hrs.	1.0-1.5 hrs.
4. Blood loss	300-400 ml/level	50-100 ml/level
5. Post-op motion	5-7 days	12-24 hrs.
6. Duration of hospital stay	7-10 days	3-4 days
7. Back to work duration	8-10 weeks	2-3 weeks
8. Spinal motion	decrease	Nearly-normal

Indication and contraindication of TADR

Indications
Best candidates are:
1.   Age 18-60 years old
2.   Patients with discogenic back pain who have been suffering from 1 to 3 levels of DDD
     with or without previous back surgery
3.   Long-term chronic back pain over 6 months.
4.   Disc herniation with back pain predominated
5.   Recurrent Disc Herniation

Contra-indications
Any patients who have following conditions
1.   Osteoporosis
2.   Spondylolisthesis
3.   Back pain from pathology  which is not originated from DDD
4.   Infection or Tumor  of spine
5.   Morbid obesity or BMI (Body Mass Index) > 40%
6.   Psychosocial disorders
7.   Spine deformities from trauma
8.   Facet  arthrosis
9.   Obvious scoliosis or kyphosis
10.  Blue-collar worker
11.  Surgeon in-experience with anterior approach to the spine

Duration of Artificial disc prosthesis

It has been experimental in vitro estimated that the artificial disc prosthesis is durable over 80 years of life expectancy, comparing to only 10-15 years post-op durability of total hip and total knee arthroplasty. The first group of patients who Cause of different durability is due to nature of the artificial disc prostheses movement on the spine, which is non-synovial tissue. Device loosening therefore frequently found in total joint arthroplasty.