Dr. Rossi, a specialist in Neurosurgery, explains the most frequent pathologies in the lumbar spine and what the treatment for each one of them consists of.
Spinal instability
This is known as the “loss of capacity of the spinal column, under physiological loads, to maintain the relationships between the vertebrae, in such a way as to cause damage or irritation of the spinal cord or roots, and therefore develop a disabling deformity or pain due to structural changes”.
There are two kinds of instability: acute, following trauma or surgery, and chronic, following disease or partial trauma. Clinically, the most important difference between the two types is the ability of the spinal cord to accommodate gradual changes and its inability to cope with abrupt changes.
Anatomy and pathology of the lumbar disc
– Bulging disc: seen in osteoporosis in response to softening of the vertebral body allowing a non-degenerated disc to expand at the superior and inferior platelets.
– Schmorl’s herniation: this is a focal herniation due to a cartilaginous plateau defect. It is usually associated with osteophytes forming what is known as spondylosis.
– Decreased height or thinning (impingement): results from loss of the nucleus pulposus in the absence of herniation. Sometimes the resorption is very marked leaving only a gas called vacuum phenomenon.
– Disc protrusion: this is the process of most neurosurgical interest, resulting from chronic structural changes and mechanical stress.
Lateral recess syndrome
The lateral recess is bordered laterally by the pedicle, dorsally by the superior articular facet and ventrally by the posterior surface of the vertebral body. Medially it is open towards the spinal canal.
There may be lumbar pain but it is not usually severe. The classic symptom is radicular pain that appears while standing or walking and that improves with postures that accentuate lumbar kyphosis such as resting leaning forward, sitting (in contrast to HDL), resting on the side or squatting. The difference with HDL is that in HDL the neural compression is ventral, while in lateral recess stenosis the compression is dorsal.
– Rheumatic pathologies
One of the characteristics of rheumatic conditions is that they cause significant morning stiffness. Typically there is a discrete improvement with mild activity, worsening again later with more prolonged or heavy activity. When rheumatic pathology is suspected, attention should be paid to the eyes, skin, and gastrointestinal tract. Low back pain is referred to the buttocks and thighs.
o Psoriatic arthritis
o Reiter’s syndrome
o Rheumatoid arthritis
o Polymyalgia rheumatica
– Neoplastic disease
Neoplasms of the spine may be primary or secondary. Among them are:
o Multiple myeloma
o Spinal metastases
– Infections
Infections of the spine may be acute (usually pyogenic organisms) or chronic (fungal or TB). Vertebral osteomyelitis can occur in any patient who has undergone surgery and does not improve local pain.
In a series of 41 patients with infectious spondylitis: 90% focal lumbar pain that worsens with percussion, 60% radicular pain, 29% spinal signs, 61% fever and in equal percentage leukocytosis and 76% elevation of the velocity. The 60% had no risk factors (recent infection, previous surgery or immunosuppression).
– Vascular or hematologic
Most vascular problems that cause low back pain are due to abdominal aortic aneurysms. Half of the patients begin with low back pain that radiates to the hips and thighs. Typically the patient is elderly and a smoker.
Rarely, low back pain may be due to epidural hematoma. They usually occur in patients who have had surgery or trauma, or in patients with higher bleeding risks such as those who are anti-coagulants. Although on other occasions it occurs without associated risk factors.
Retroperitoneal hematomas at the level of the psoas, for example, occur spontaneously in anti-coagulated patients or secondary to trauma.
– Metabolic or endocrine factors
The most common metabolic condition is osteoporosis. It occurs in older post-menopausal women, although there are other causes such as endocrine conditions, nutritional deficiencies, effect of drugs and medications and certain genetic disorders.
Compression fracture pain is very severe for many weeks and decreases over months. It is spontaneous in 46%, due to trivial trauma in 36%. Paradoxically, 50% of osteoporotic fractures are asymptomatic. Although the pain worsens with prolonged sitting or standing.
– Referred pain
Many clinical signs may suggest that low back pain has its origin outside the spine or paravertebral tissues. They may originate from the abdomen or pelvis and the pain may be associated with eating or the menstrual cycle, or show no relationship to movement or activity.
The pain may be of renal origin, endometriosis, fallopian tube, ovarian cyst rupture, pancreatic origin or ulcer origin (especially ulcers affecting the posterior wall of the duodenum).
– Pain of mechanical cause
98% of low back pain is caused by a mechanical cause. There is a close relationship between pain and position and postures that load the spine such as sitting or static postures worsen pain.
70% of chronic low back pain is due to: HDL, facet joints and sacroiliac joints.