Spondylolisthesis is a condition of the spine, most commonly seen in the lumbar or lower back region. It occurs when one vertebra (spinal bone) slips, most usually out of place in a forward direction. There are four grades of spondylolisthesis:
- Grade 1: 1-25% slip
- Grade 2: 26-50% slip
- Grade 3: 51-75% slip
- Grade 4: 76-100% slip
There are various types of spondylolisthesis including:
- Congenital spondylolisthesis (abnormality present at birth),
- Isthmic spondylolisthesis (small stress fractures in the vertebra causing weakness and allowing for slippage),
- Degenerative spondylolisthesis (altered spinal structures due to age),
- Traumatic spondylolisthesis (slippage due to a major trauma),
- Pathological spondylolisthesis (due to an underlying bone weakening disorder such as osteoporosis), and
- Post-surgical spondylolisthesis (slippage that either occurs or worsens due to surgery).
The symptoms of spondylolisthesis vary from asymptomatic (no pain) to mild lower back pain or severe lower back pain. The pain may be accompanied by muscle spasms, pain and tightness down into the hamstrings and/or leg and foot numbness, pins and needles or a burning sensation.