Well, nice title eh? You might be wondering what it means. Well, a simple Google will help you alot, and it is the name of the condition I'm currently suffering from.

The most common X-ray identified cause of low back pain in adolescent athletes is a stress fracture in one of the bones (vertebrae) that make up the spinal column. Technically, this condition is called spondylolysis (spon-dee-low-lye-sis). It usually affects the fifth lumbar vertebra in the lower back, and much less commonly, the fourth lumbar vertebra. For me, its the fourth lumbar vertebra (L4).

If the stress fracture weakens the bone so much that it is unable to maintain its proper position, the vertebra can start to shift out of place. This condition is called spondylolisthesis (spon-dee-low-lis-thee-sis). If too much slippage occurs, the bones may begin to press on nerves and surgery may be necessary to correct the condition.

So, I just got a letter that exempts my from any physical activities till June next year, which means no NAPFA =) The doctor also said that I can be able to play football, but of course my condition might get worse. I'm due for another x-ray in February to see how the crack is doing, and further precautions will be taken from then.

More info here: http://orthoinfo.aaos.org/fact/thr_report.cfm?Thread_ID=155&topcategory=Spine