Physical Factors Associated With Stage Progression of Lumbar Spondylolysis: A Prospective Cohort Study in Male...

Lumbar spondylolysis (LS) has distinct pathologic stages, and worsening LS can cause poor bone union and low back pain. However, the risk factors involved in LS pathogenesis remain unclear.

To identify risk factors associated with the pathologic progression of LS at the L5 in adolescent male soccer players.

Case-control study; Level of evidence, 3.

A total of 189 male adolescent soccer players aged 12 to 14 years were recruited. We used lumbar magnetic resonance imaging (MRI) to examine adolescent soccer players' lumbar lordosis (LL), sacral slope (SS), sacral rotation angle, maturity stage of the lumbar vertebral bodies, and bone marrow edema (BMO) at L5. In addition, whole-body dual-energy x-ray scans measured bone mineral density and content as well as trunk lean body mass. Moreover, we tested the flexibility of the iliopsoas, hamstrings, and quadriceps, as well as evaluated the range of motion (ROM) of the hip in both external and internal rotation. LS stages were determined using computed tomography (CT)-like and short-tau inversion recovery (STIR) modes. The change over the 6-month period was the main outcome; participants were classified as "worsened,""improved," or "no change." The worsened group was defined by a pathological progression on CT-like mode or new BMO appearance on STIR mode without CT-like change. Multiple logistic regression analysis was then performed to identify risk factors for the pathologic progression of LS.

Of the 163 players analyzed, 47 (28.5%) showed LS progression. BMO (odds ratio [OR], 5.54; 95% CI, 2.23-13.76), SS relative to LL (OR, 5.58; 95% CI, 2.32-13.51), sacral rotation angle ≤-1.5 or ≥1.5 (OR, 5.74; 95% CI, 2.36-13.96), and hip external rotation ROM (OR, 4.30; 95% CI, 1.67-11.06) were significantly associated with the pathologic progression of LS.

Our study demonstrated that the risk factors for LS progression in male adolescent soccer players include BMO, sacral anteversion relative to LL, sacral rotation, and restricted hip external rotation ROM. Early BMO detection and sacral malalignment improvement may prevent pathologic LS progression in male adolescent soccer players.