Introduction:
Lumbar spondylolysis, a stress fracture in the lumbar spine, presents a significant health concern in athletic populations, affecting both performance and well-being. This study aimed to elucidate the prevalence and characteristics of the terminal stage of lumbar spondylolysis in professional Japanese baseball players.
Methods:
This observational study analyzed 169 professional baseball players in Japan who underwent medical check-ups between December 2012 and December 2023. Data were collected through lumbar CT, MRI, and their experiences with lower back pain, previous diagnoses, duration and content of treatment (such as bracing, activity restriction, physical therapy, and pain control), and treatment outcomes from the detailed players and their family interviews and/or medical information forms that had been collected from the respective treatment hospital. Descriptive analyses were performed to assess the prevalence and treatment patterns.
Results:
Of the 169 professional baseball players examined, 49 (29.0%) had terminal-stage lumbar spondylolysis. Of the 49 players with terminal-stage lumbar spondylolysis: Ten players (20.4%) reported no previous history of low back pain and were first diagnosed with lumbar spondylolysis during the medical checkup upon joining the team. Thirty-nine players (77.3%) were aware of low back pain before joining the team during adolescence. Among the 39 players who experienced pain at the onset, 30 players (76.9% of those aware of pain) sought medical attention and were diagnosed with a lumbar stress fracture or suspected lumbar spondylolysis. Of these 30 players, only four (13.3% of those diagnosed) accepted conservative treatment to achieve bone healing at the medical institution. The average duration to return to play for the four players was 3.9 months (1.5 – 6 months). The remaining players, who were aware of their low back pain (26 out of 30), continued playing baseball with minimum rest and managed their condition using pain control strategies. The average duration of return to play for the 26 players was 0.8 months (0 – 6 months). In contrast, among the 120 players who did not have terminal stage lumbar spondylolysis, eight players (6.7%) were diagnosed with lumbar stress fracture and five players (4.2%) received treatment to achieve bony fusion before joining the professional team. All five players had unilateral lesions, and the average duration to return to play was 3.5 months (range, 1–6 months). To summarize the adolescent treatment history in the timeline, of the 169 professional baseball players, 79 players developed low back pain during adolescence, 38 of whom were diagnosed with lumbar spondylolysis; of these 38, only nine players underwent conservative treatment to achieve bony healing, and the five players who had bony union were all unilateral lesions.
Discussion:
The high prevalence of terminal-stage lumbar spondylolysis and the low success rate of conservative treatments in achieving bone union before professional play highlight significant challenges in managing this condition in Japanese professional baseball. These findings emphasize the need for early detection and effective management strategies in adolescent athletes with lumbar spondylolysis.