Stress reactions involving the pars interarticularis in young athletes

Abstract

A stress reaction involving the pars interarticularis of the lumbar spine was confirmed in seven young ath letes with a positive technetium pyrophosphate bone scan. No pars defects were detectable on their lum bosacral roentgenograms, which included oblique views. The return to normal levels of radioactive up take on repeat bone scans correlated closely with their clinical course. If the bony reaction is recognized early, it may heal at a subroentgenographic level and prevent the development of lumbar spondylolysis. These early lesions usually show unilateral in creased uptake at one lumbar level on the bone scan and, initially, the athlete localizes the pain to the corresponding unilateral lumbar paraspinous area. The "one-legged hyperextension test" is positive on the ipsilateral side and aggravates the pain. Treatment consists of avoiding the aggravating ac tivities and resting. The average time for return to pain-free competition was 7.3 months. These devel oping defects may be the source of considerable prolonged disability in the young athlete, particularly if undiagnosed and untreated.