The broad based disc herniation at L4-L5 level represents a backward movement of your disc (commonly referred to as slip disc). This disc may compress the nerves within your spinal canal
and cause pain (usually shooting pain radiating along your thigh and leg). However, in your case the herniation is mild and does not appear to be a cause of much worry. However, if you do have shooting pain / tingling
of your feet or toes then you may need to consult an Orthopaedic Surgeon
to treat the disc herniation.
Sacralization of the L5 vertebra is a common variant in the anatomy of the vertebral
column. It usually does not cause any problems except that it makes the L4-L5 disc more prone to stress and this has probably contributed to the mild disc herniation that you have at this level. However, the sacralization need not be a cause of worry for you.
The rest of the findings on your scan are near normal for your age and body habitus.