Diseases

Introduction

Back pain is an extremely common condition that can occur to anybody of any age. However, certain groups of individuals, such as those who exert a lot of force on the low back and those who sit all day long at work as well as athletes, are prone to lower back injuries.

Anatomy

The low back consists of the lumbar vertebral bodies, as well as the ligaments and muscles surrounding it. As it carries all the weight of the torso, it is the most frequently injured area of the spine.
The motion in the low back is divided between five motion segments, although a disproportionate amount of the motion is in the lower segments (L3-L4 and L4-L5). Consequently, these two segments are the most likely to breakdown from wear and tear (e.g. osteoarthritis). The two lowest discs (L4-L5 and L5-S1) take the most strain and are the most likely to herniate. This can cause pain and possibly numbness that radiates through the leg and down to the foot (sciatica).

Cause

The vast majority of episodes of low back pain are caused by muscle strain. Trauma to the muscles and other soft tissues such as ligaments in the low back can cause severe and debilitating pain. This could be caused by sprains, falls or direct impact. But the most common cause of muscle strain is improper posture while seated, working or resting. As the bones, joints and related muscles become over-fatigued due to a lack of proper stretching and a shortage of nutrient supplies in the blood stream, they will experience pain.
Some conditions that may have caused low back pain are as follows:
1. When nerve roots in the lumbar spine are pinched by swollen bone spurs or by a herniated disk, they will experience pain, numbness and loss of function.
2. Dislocation or tear of intervertebral discs.
3. Infection of the vertebral bodies or the intervertebral discs.
4. Acute or chronic foramen inflammation, spinal inflammation or ankylosing spondylitis, etc.
5. Bone fractures or dislocation of joints along the vertebral column.
6. Tumor in the spine or spinal cord.
7. Narrowing of the spinal canal and the subsequent pinching of the nerve roots.

Symptoms

Back pain may be acute or chronic. Acute pain lasts four to six weeks, but chronic pain is persistent, long-term and sometimes last throughout one’s life. The pain may come suddenly and produce a sharp sensation, or it may be dull. Movements, such as coughing and sneezing, may aggravate the pain. You may also have numbness in your legs, which is often referred to as sciatica. This is caused by a pinched nerve in the low back that travels along the leg.
In some rare cases, there is marked numbness and a lack of strength in the muscles of the lower limbs; their tactile senses become less sharp and the joints and muscles are constantly stiff. If these symptoms persist or if you detect other symptoms as follows, please consult a physician immediately:

1. Constant pain in the low back, especially during the night, with conditions not improving after more than two to three weeks.
2. The pain has not reduced despite staying in bed, resting or taking anti-inflammatory medication.
3. Lower limb weakness
4. Bowel or bladder incontinence.
5. Excessive forward curvature of the spine (kyphosis, or hump back) or lateral curvature (scoliosis).
6. Fever or sudden weight loss.

Diagnosis

An orthopaedic specialist would first obtain the medical history of the patient and perform physical and neurological exams. In the physical exam, your doctor will observe your posture, range of motion and physical conditions, noting any movement that causes you pain. Your doctor will feel your spine, note its curvature and alignment, and feel for any muscle spasm. You may be asked to lie on an examination table and raise your legs. During the neurological exam, your orthopaedic specialist will test your reflexes, muscle strength, any nerve changes and if the pain is spread to other parts of the body. This is to identify the cause of your back pain and develop a treatment plan – a way to manage your pain and other symptoms and to help you recover.

By using X-ray or CT scan, the orthopaedic specialist will be able to determine if the patient has certain common spinal diseases that cause low back pain, numbness in the hips and loss of strength in the lower limbs, affecting daily life and work. These diseases include:
1. Injury or tear of soft tissues along the spine.
2. Damage of the spinal structure due to external injuries, long-term compression or excess loading, which affects the stability and range of motions.
3. Degeneration, inflammation, swelling and spur at the facet joints, which leads to pain or damage of the adjacent nerve roots, affecting the neuromuscular function of the lower limbs.
4. Degeneration, dislocation, hernia, calcification and ossification of intervertebral discs, which causes the narrowing of the spinal canal and intervertebral foramen, which in turn compresses the spinal cord and nerve roots in the foramen, damaging the functions of the nervous system.

Besides X-ray and CT scans, the orthopaedic specialist may also take blood samples, conduct MRI scans, Positron Emission Tomography (PET) or even Tc-HIDA Scan to find out the causes, gauge the conditions and help decide if a surgery is needed.

Non-surgical treatment

If your back pain is caused by a muscle sprain or strain, that usually heals on its own over time. Conservative treatment includes analgesics, physiotherapy and other alternative therapies such as acupuncture. Prolonged bed rest is not advised since clinical studies have revealed that too much rest makes the back pain worse. Oral medications and injections may help to relieve the back pain. Physiotherapy such as deep tissue massage, hot and cold therapies, TENS (transcutaneous electrical nerve stimulation), ultrasound and active exercise may help to relieve the back pain, strengthen your body and prevent recurrence of back pain.

Surgical treatment

Most sprains and strains in the back do not require surgery, as surgery is reserved for the most severe cases of back pain such as structural deformity and severe cases of spinal stenosis. Statistically, only about 5% of the patients suffering from back pain would require surgery. You may consider surgery only if you have the above pathology and if several months of non-surgical treatment fails to yield any satisfactory results.

Depending on the particular pathology causing pain in the back and the leg, different kinds of surgery, such as decompression (laminotomy, laminectomy and discectomy) and fusion technology, may be performed to reduce pain, deformity and any nerve impingement.

Rehabilitation

After surgery patients are given physiotherapy to strengthen their back muscles as well as the core muscles in order to prevent recurrent back pain and injury. Depending on the kind of surgery performed, different rehabilitation programmes will be administered to improve the function of the patients and to ensure an early return to work and daily activities. For single-level discectomy, the patient usually can move about the day after the surgery. However, if major decompression surgery with spinal fusion is performed, the patient will require gradual mobilisation exercise and sometimes a lumbar corset will be prescribed for a few months to improve the success rate of fusion.

Prevention

1. Proper posture
Maintaining a proper posture, i.e., the natural curve of the spine, is important as it will minimise the amount of harmful stress to the spine. Proper posture should be maintained not only when standing or sitting, but in all daily activities. 

2. Safe way to carry objects
Before carrying any object, make sure you have a proper assessment of the weight and shape of the object and the amount of time you will be spending to move the object.
Try to hold the object at the side and bottom while keeping it close to the body. Remember to keep the back straight.
The shoulders should be held slightly back and level.
The ear should line up with the shoulder on the side view.
The chin is slightly tucked and the pelvis is shifted forward so the hips are aligned with the ankles.

3. Safe way to lift objects
First, take a look at the object to be moved. Ask somebody to help if the object is too heavy.
Remove any obstacles in the way before lifting the object.
Never bend down to lift the object. Maintain good posture and keep the head properly aligned. Try to get as close to the object as possible and bend at the knees.
Keep breathing and tighten the stomach muscles. Smoothly lift the object using the arms and legs instead of the back.

Dr. MAK, Kan-hing