Spondylolysis is a stress fracture of the pars interarticularis, a thin bridge of bone at the back of a vertebra, most often at L5. It is a common cause of low back pain in teen athletes who repeatedly arch the back, such as gymnasts, divers and football linemen.
Key symptoms
- Low back pain worse with arching, twisting or sports
- Pain eased by rest
- Pain usually on one side of the low back
- Tight hamstrings
What you find on exam
- Pain with one-leg standing back extension (stork test)
- Tenderness over the lower lumbar spine
- Hamstring tightness and posture
- Neurologic exam, usually normal
Tests
- Lumbar X-rays; oblique views may show the Scottie dog collar sign
- MRI without radiation to find early stress reactions
- CT to define the fracture and check healing
Treatment basics
- Stop sports that load the back, often for 6 to 12 weeks
- Physical therapy for core strength and hamstring flexibility
- Brace in selected cases
- Gradual return to sport when pain-free; surgery only for persistent pain
Red flags
- Leg weakness, numbness or bladder changes
- Back pain with fever, weight loss or night pain
- Increasing forward slip (spondylolisthesis) on follow-up imaging
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.