This 2016 study evaluated the usefulness of patient history and physical examination for identifying spondylolysis and/or spondylolisthesis in athletes and they found that…
- Age less than 20 years had 81% sensitivity and 44% specificity
- Being male had 73% sensitivity and 57% specificity
- Pain worse with sitting, walking and waking up, and difficulty falling asleep because of pain, all have >75% sensitivity
However, the palpation of a step-deformity had 88% sensitivity and almost 100% specificity for spondylolisthesis.
This means that if you can palpate the L4 or L5 spinous process protruding out, recommending an oblique x-ray is justifiable.
I consider the diagnosis on my young (age <20) patients involved in athletic activities that require extreme rotation and extension; such as baseball, diving, dancing, figure skating, etc.
Reference: Grødahl LH et al Diagnostic utility of patient history and physical examination data to detect spondylolysis and spondylolisthesis in athletes with low back pain: A systematic review. Man Ther. 2016 Aug;24:7-17.