The two bones in spinal column are separated by a cushion like structure called intervertebral disc. The disc consists of inner soft jelly like structure called nucleus and is surrounded by tough fibres called annulus. When the inner soft portion (nucleus) of the disc comes out of its normal position between the two spinal bone, the condition is known as slip disc. So disc herniation is the popping out of the nucleus through the annular layers.
A herniated disc can irritate the surrounding nerves causing numbness, weakness or pain in arms or legs and back pain. Most of the disc herniation can be managed with conservative care while only a few will require surgery.
Most common cause is disc degeneration i.e. age related wear and tear of the disc. Some may develop wear and tear early in life while in some it may occur at a later age. The disc becomes less flexible along with age and hence loses elasticity. Such discs are more vulnerable to injuries and through one of the cracks in the annulus the disc herniates.
Most people cannot pinpoint a single incident that led to disc herniation. While a few of them have the herniation after lifting heavy weight, bending forward or after fall/injury.
The risk factors for developing disc herniation are: excess weight, smoking, occupation with repeatitive twisting, bending of back and lifting activities, sedentary life-style (prolonged sitting) and a genetic predisposition (family history).
Pain radiating dowh
Based on detailed history taking and thorough clinical assessment, doctor will ask for appropriate investigations. The gold standard investigation to diagnose or rule out disc herniation is MRI (Magnetic Resonance Imaging). It gives information regarding the type of disc herniation, compression on the nerves, spinal joint conditions, muscles and bony alignments.
Plain x-rays or CT-Scans don’t actually detect disc herniation but based on the distance between the two vertebral bodies an assumption can be made as to which level is affected. In patients when MRI is contraindicated (due to pace-makers or ferromagnetic implants) a special type of CT-Scan known as CT-Myelography can be helpful for diagnosis of symptomatic disc herniations. In some patients Nerve conduction studies (EMG, NCV) may be necessary to differentiate the radiculopathy due to a disc herniation or other neurological problems. It also helps in prognosticating outcomes in such cases.
It is very important to note that all disc herniation dues not lead to a surgery. On the contrary, majority of disc herniations (90%) can be managed with just conservative care. Disc is an avascular structure and does not have its own blood supply. So when there is herniation, the body recognises the disc as foreign material and with the help of inflammatory cells tries to hydrolyse it and reduce it. In majority of patients our body is successful and the patient gets better. This process may take up to 4-6 weeks.
To facilitate our body’s own natural mechanism, we advise our patients a small duration of bed rest (5 days), spinal bracing, anti-inflammatory and/or neuromodulator medicines and physiotherapy.
Bed Rest: Complete bed rest is usually to tide over the acute episode only. In very severe cases, patients are advised bed rest in hospitals with intravenous injections of various medicines. Patients may be totally bed bound if pain is very severe or else the patient may get up (only) for toiletry activities. Resting on your back with pillow below the knee or resting on side with pillow between legs are preferred positions. Prolonged bed rest is usually discouraged as it may weaken spinal muscles and do more harm than good. Once the pain reduces, light activities are encouraged. But heavy activities or working in sitting position is to be avoided for weeks or months. Totally avoid bending forward, sitting on floor, lifting weight and using Indian style toilets.
Medications: Two kind of pain killers are used. 1) Opioids that very effectively reduces pain and 2) NSAIDS/paracetamol/oral steroids that reduce pain and inflammation both. Apart from these medications neuromodulators such as pregabalin or gabapentin help to reduce pain from nerve root irritation or compression. Very rarely muscle relaxants or anti-depressant drugs are prescribed.
Braces: Spinal braces provided comfort and they act like pain killers. Also it reminds you not to twist, bend or stretch your back. So the braces are to be used as mentioned by your doctor. But neither it realigns the troubled spine nor it pushes the disc back inside.
Physiotherapy: During acute painful condition modalities like SWD, TENS, Ultrasound, Lasers etc might help. Once the pain subsides usually extension dominant back strengthening exercises starts to strengthen back muscles without increasing the pressure on the discs. There are phases of exercises during the recovery phase and hence it is important to visit therapist regularly/periodically.
Alternative medicine: Acupuncture, Chiropractor, Massage, Ceragem and Ozone injections are commonly available alternative medicines. Patients can try these at their own risk and we don’t recommend these medicines as of now due to conflicting evidences. However for a healthy person not who doesn’t have a spinal problem regular Yoga, swimming and walking/jogging can be preventive to a certain extent.
Spinal Injection: There are different types of spinal injection such as interlaminar epidural injection, transforaminal nerve root injection or a caudal epidural injection. During the injection we inject local anaesthetic agent and steroid at the site of disc herniation. This procedure is a day care procedure, performed in the theatre and under image guidance. But the patient is not sedated and remains awake during the procedure. Patient can go home after few hours if he/she feels better. This procedure is very safe in expert hands and the complication rate is negligible (< 1%). However, it is important to note that the medicines may provide relief for few days to months. And if the primary pathology persists the pain may come back again. But it is very important tool to reduce pain during acute episode. Some times there are many disc herniations, so in that case injection given at a single level also helps patient and doctors to know how much is the contribution of pain from that level.
Surgery: If there is no relief with conservative care after 4-6 weeks, or if there is significant weakness in legs, or urinary/bowel disturbances patients are advised for surgery. The surgery is basically aimed to remove the disc from its abnormal location and thereby free the nerves (microdiscectomy, Laminectomy, Foraminotomy, Flavectomy).
Sometimes the whole disc (including the non-herniated portion) needs to be removed and the spine has to be fused with bone grafts. Since the fusion may take months it has to be protected with implants (Lumar spinal fusion such as TLIF, PLF, PLIF, ALIF, XLIF). This is done in cases where there is a risk of developing instability after disc removal surgery. The good news is that all the procedures can be performed with a stitch-less minimally invasive spine surgery (MISS). In MISS surgery is done via key-hole technique (microendoscopic discectomy) or a coin-hole technique (MIS-TLIF) and patient can walk on the same day of the surgery. In a few cases, the surgery is done with patient awake (full-endoscopic spine surgeries) and the patient can walk immediately after the surgery. The technology is so advanced nowadays that majority of patients (>99%) don’t suffer from post-operative paralysis (contrary to common fear of the patients). However it is pertinent to discuss the risk-benefit ratio with the doctor before going for any intervention.
There is a risk of 4-11% chance of disc herniation to recur with or without spine surgery. Sometimes it is the adjacent level disc that is causing a new problem. Important thing to note is that the recurrence rate is highest in the first year following the surgery. Hence if a patient takes proper precautions to avoid sudden bending, lifting weight its incidence can be reduced. Also the recurrence rate is common in smokers, obese patients, heavy weight lifters. So better to control these risk factors