Intervertrebal disc herniation

The spinal column is the central, weight-bearing element of the human body and surrounds and protects the spinal cord. Its double S-shaped configuration is stabilized by the surrounding ligaments, tendons and muscles and allows a dynamic, upright gait while dampening the forces transmitted upwards to the skull and brain. The individual vertebrae are connected to each other by intervertebral discs which act as small shock-absorbers, reducing jolting forces.

The discs themselves are formed from a soft, central gelatinous core enveloped by an outer fibrous ring responsible for stability. A lifetime of physical stresses can cause swelling of the disc and can result in the gelatinous core pushing the fibrous ring component of the disc against the long posterior ligament positioned between the disc and the spinal canal.

When the disc bulges out in this way it can cause pressure on the spinal nerves, especially when it protrudes to the side of the canal where these nerves exit.

Disc herniation occurs when the fibrous ring tears and the gelatinous core bulges out from the disc. Such “slipped discs” are very painful and prolonged pressure on the nearby nerve structures can lead to sensation disturbance, leg weakness and walking problems. Depending on the position of such disc herniations, distinct patterns of symptoms are usually seen.

The diagnosis of a disc herniation or a protruding disc depends on three main factors: symptoms, neurological findings and medical imaging. High-resolution MRI (magnetic resonance imaging) can be performed with special sequences while lying down or while standing-up to show the detailed anatomy of the intervertebral disc region, the spinal canal and the nearby neural structures.

Treatment for a herniated or protruding disc is decided on a case by case basis. Even when a disc or its surrounding structures show pathological changes, an operation is not always necessary and in patients presenting with pain, first line therapeutic measures include

• rest
• medications to relax muscles and reduce inflammation
• physical therapy

In some cases, it is possible to infiltrate the nerve root with a CT scan or pulsed fluoroscopy to bring a drug close to an irritated nerve root, thereby relieving pain and relaxing the muscles.

Only when these conservative therapies do not achieve the desired results or neurological damage such as muscle weakness in the legs has occurred, an operation on the disc is indicated. In rare cases presenting with sudden and severe leg weakness or problems with bladder control, urgent surgical intervention may be required.

The microsurgical removal of a herniated disc is performed under an operating microscope using precise microsurgical instruments and techniques. The objective is the complete removal of the herniated disc elements and the relief of pressure on all neural structures.

An operation on a herniated disc in the lumbar region of the spine is usually performed through a skin incision a few centimeters in length and removed with the assistance of an operating microscope and sometimes with the help of an endoscope and electrophysiology monitoring.

A diamond drill is used to prepare the area around the involved nerve roots with gentle precision until it is possible to get a full overview of the prolapsed disc and all the important structures in its vicinity. In this way, the risk of a nerve injury can be reduced to a minimum and all structures irritating the nerve root can be successfully removed.

In the cervical (neck) region, disc herniations are usually treated via a small, horizontal incision at the front or to the side of the neck. Approaching from the front in this way has the advantage of avoiding the need to remove the disc past the fragile spinal cord, lying behind the disc in the spinal canal. It also permits excellent visualization of the disc.

Once removed, the disc is replaced with a “cage” prosthesis, the correct positioning of which is confirmed during the operation using X-ray imaging.

In the case of a small disc herniation which compresses the exiting nerve root from the side only, an operation can be performed through a small midline incision in the back of the neck – this allows for the targeted decompression of the nerve root by removing prolapsed disc components (Frykholm Operation).

In all cases of herniated discs requiring operation the success of the therapy is heavily reliant on the decisive input of the physiotherapy team working alongside the surgeons. Our experienced team of physiotherapists ensure that, from the first day at Klinik Hirslanden, movement exercises are gently and safely performed and that the spinal musculature is built back up, thereby alleviating pain and providing stabilization in the recovery period.