So,if lumbar spine gets affected it results in severe complications of the spine.
1.Spinal Stenosis:
This condition causes pain through narrowing of the spinal canal where the nerve roots are located.The narrowing can be central,forminal, or both,and can be at a single level or multiple levels in the lower back.

Original Credit:Google.com

2.Spondylolisthesis:
This condition occurs when one vertebra slips over the adjacent one.
Most common type of spondylolisthesis is:
*Secondary to a defect or fracture of the pars (between the facet joints) or mechanical instability of the facet joints (degenerative),pain can be caused by instability (back) or compression of the nerves(leg).

Original Credit:Google.com
3.Deformity:
Curvature of the spine can include scoliosis or kyphosis.So,deformity may be associated with lower back pain if it leads to the breakdown of the discs,facet joints, sacroiliac joints or stenosis.

Original Credit:Google.com
4.Osteoarthritis:
This condition results from wear and tear of the disc and facet joints.It causes pain,inflammation,instability and stenosis to a variable degree, and can occur at a single level or multiple levels of the lower spine.Spinal osteoarthritis is associated with aging and is slowly progressive referred as spondylosis or degenerative joint disease.

Original Credit:Google.com