ABOUT
The spine is made up of several brick-like bones called vertebrae, stacked upon each other. These are roughly circular and between each vertebra is the intervertebral disc. The discs are made of strong rubber-like tissue, which allows the spine to be fairly flexible. A disc has a stronger fibrous outer part called the annulus fibrosus, and a softer jelly-like middle part called the nucleus pulposus.
The spinal cord, which contains the nerves that come from the brain, is protected by the spine and these nerves run just behind the discs. Nerves come out from between the vertebrae close to the discs and exit through the neural foramen. When you have a prolapsed disc, part of the inner softer part of the disc (the nucleus pulposus) bulges out and can press on nearby structures such as a nerve coming from the spinal cord. Some inflammation also develops around the prolapsed part of the disc.
Any disc in the spine can prolapse. However, most prolapsed discs occur in the lumbar part of the spine (lower back). The size of the prolapse can vary. As a rule, the larger the prolapse, the more severe the symptoms are likely to be. A prolapsed disc causes severe lower back pain and when the disc presses on a nerve root, severe pain and neurological symptoms occur in the leg. In most cases, the symptoms ease off gradually over several weeks. The usual advice is to do normal activities as much as possible. Painkillers may help. Surgery is an important option if the symptoms persist.
The most common age to develop a prolapsed disc is between 30 and 50 years. It is more common in the males than females. It is not clear why some people develop a prolapsed disc and not others. Activities that suddenly increase the intra-abdominal pressure such as sneezing, awkward bending, or heavy lifting in an awkward position may cause extra pressure on the disc, allowing out to prolapse outside. Other factors that may increase the risk of developing a prolapsed disc include job involving lifting, a job involving lots of sitting (especially driving), weight-bearing sports (weight lifting, etc), smoking, obesity, and increasing age (a disc is more likely to develop a weakness with increasing age).
SYMPTOMS & DIAGNOSIS
The following are the symptoms and diagnostic steps
Sciatica- Sciatica or the shooting leg pain is typical of a prolapsed disc. It is pain that occurs because a nerve coming from the spinal cord is compressed by a prolapsed disc, or is irritated by the inflammation caused by the prolapsed disc. Patients should understand that though the problem is in the back, they will feel the pain along the course of the nerve in addition to back pain. Therefore, patients feel the pain down a leg to the calf or foot. Nerve root pain can range from mild to severe, but it is often worse than the back pain. With a prolapsed disc, the sciatic nerve is the most commonly affected nerve. (The term sciatica means nerve root pain of the sciatic nerve.) The irritation or pressure on the nerve next to the spine may also cause pins and needles, numbness or weakness in the buttock, thigh, leg or foot. The exact location and type of symptoms depend on which nerve is affected.
Cauda equina syndrome is a particularly serious problem that can be caused by a prolapsed disc. This is a rare disorder where the nerves in the centre of the spine are compressed by massive disc prolapse. This syndrome can cause low back pain, problems with bowel and bladder function (usually unable to pass urine), numbness in the perineum (around the anus, scrotum, genitals), and weakness in one or both legs. This syndrome needs urgent treatment to preserve the nerves to the bladder and bowel from becoming permanently damaged.
Tests such as X-rays or scans may be advised. In particular, an MRI scan is essential and will show the site and size of a prolapsed disc.
TREATMENT
Physiotherapy, Medication and Surgical options are available.
Usually, 60-70% of prolapsed discs become better on their own by rest, analgesics and a gradual return to activities. Continue with normal activities as far as possible. Activities that cause a lot of pain are avoided. Also, sleep in the most naturally comfortable position on a comfortable surface. The use of hard beds, pillows have also been not advised now.
Pain killers are required to ease the pain. Paracetamol, Non-steroidal anti-inflammatory drugs like diclofenac or Ibuprofen are preferred. Paracetamol is often sufficient if taken regularly at full strength. For an adult, this is 1000 mg (usually two 500 mg tablets), four times a day. Some people with asthma, high blood pressure, kidney failure, or heart failure may not be able to take anti-inflammatories. The use of oral steroids in some patients can be considered.
Surgery in the form of microsurgery provides the best and immediate pain relief. As a rule, surgery may be considered if the symptoms have not settled after about four weeks. All patients must have an adequate period of conservative treatment of at least 3–6 weeks before surgery is advocated. Relief of radicular pain is the primary surgical indication in most patients. While urgent intervention is required for severe and progressive neurological deficits, there is considerable controversy regarding the relative urgency of surgery in the face of chronic and static neurological deficits. However, an absolute surgical indication is the development of cauda equina compression syndrome matched by relevant MRI findings. Patients with normal neurological findings but without pain relief even after an adequate trial of conservative therapy may also be considered for surgical intervention. Relative indications for surgery include patients who express a preference for early surgery for reasons of intolerance to pain or need for an early return to work.
Microsurgery for Disc Prolapse
The aim of surgery is to cut out the prolapsed part of the disc through a micro-incision.
The advantages of the microsurgery are:
- Small Incision: The operating microscope enables magnification and illumination of the surgical field. Hence with a small skin incision and minimal damage to the paravertebral muscles, the interlaminar space is clearly exposed.
- Safety of Nerves: The clear surgical field facilitates gentle handling of neural structures. The operating time can be reduced and the complications are fewer.
- Less Muscle Injury: The preservation of muscle insertions and the segmental innervation of the paravertebral muscles due to limited retraction also help in quicker rehabilitation.
- Less Bone Removal: The use of the microscope obviates the need for laminectomy and avoids damage to the facet joint, thereby retaining spinal stability.
- More Physiological: In selected cases at L5/S1 levels, the ligament flavum can be raised as a flap and preserved, thereby reducing the incidence of postoperative adhesions. The epidural fat and epidural venous plexus can be preserved.
- Less Scarring: Exploration of the target disc with limited manipulation of the nerve root helps to prevent perineural adhesion formation.
- Less Blood Loss: Due to the possibility of identification and coagulation of epidural veins, better hemostasis and reduced blood loss are achieved.