Background:Recent studies utilizing magnetic resonance imaging (MRI) for the evaluation of symptomatic lumbar spondylolysis in pediatric and adolescent athletes have indicated that upper level lumbar involvement has a higher incidence than previously reported. There has been a paucity of literature evaluating sport-specific patterns of lumbar spondylolysis, specifically upper versus lower level involvement.Purpose:To assess the potential risk factors for upper level stress injuries of the lumbar spine in pediatric and adolescent athletes.Study Design:Cross-sectional study; Level of evidence, 3.Methods:The medical records of 902 pediatric and adolescent athletes (364 female, 538 male; mean age, 14.5 ± 2.1 years) diagnosed with symptomatic pedicle and pars interarticularis stress injuries at 2 academic medical centers (July 2016 to June 2021) were reviewed. All patients had undergone MRI at the time of diagnosis. Only patients with pars/pedicle edema on MRI were included. Data regarding single-sport specialization, sport participation, sport category by biomechanics (axial rotation vs extension/axial loading), and vertebral level of injury over the 5-year period were analyzed. Stress reaction or active spondylolysis (SRAS) was the terminology used to designate grade 1, 2a, or 3 stress injuries according to the adapted Hollenberg classification system on MRI. Upper level vertebrae were defined as L3 or superior, whereas lower level vertebrae included L4 or inferior.Results:Of the 902 patients with SRAS injuries, most (n = 753 [83.5%]) had exclusively single-level lower stress injuries, while 67 (7.4%) had multilevel stress injuries. There were 82 athletes (9.1%) who had single-level upper stress injuries. Athletes with upper level pars/pedicle stress injuries were older at the time of diagnosis (15.8 ± 1.9 vs 14.3 ± 2.1 years, respectively; P < .001), had a shorter duration of low back pain before presentation (2.50 ± 2.70 vs 4.14 ± 6.73 months, respectively; P < .001), were more likely to specialize in a single sport (43.9% vs 32.3%, respectively; P = .046), and had a lower incidence of active spondylolysis on MRI at the time of diagnosis (42.7% vs 59.8%, respectively; P = .004) compared with athletes with lower level stress injuries. Athletes with lumbar stress injuries who specialized in a single sport had nearly twice the odds of having upper level involvement compared with multiple-sport athletes (adjusted odds ratio, 1.80 [95% CI, 1.06-3.04]; P = .03). Athletes with active spondylolysis on MRI at the time of diagnosis had nearly half the odds of having upper level involvement (adjusted odds ratio, 0.55 [95% CI, 0.33-0.91]; P = .02).Conclusion:Age at the time of diagnosis, duration of low back pain, single-sport specialization, and presence/absence of active spondylolysis on MRI at the time of diagnosis were primary predictors of whether an athlete’s lumbar stress injury was classified as either upper or lower level involvement. Overall, the variables included in multivariate analysis were modest predictors, explaining only 15.1% of the variance in the rates of lumbosacral stress injuries classified by spinal level. These specific biomechanical factors and other potential contributors to these findings warrant further investigation.

中文翻译：

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902 名儿童和青少年运动员运动中腰椎关节间部和椎弓根应力损伤的特征：一项回顾性研究


背景： 最近利用磁共振成像 （MRI） 评估儿童和青少年运动员症状性腰椎分离症的研究表明，上部腰椎受累的发生率高于既往报道。缺乏评估腰椎分离运动特异性模式的文献，特别是上部与下部受累。目的： 评估儿童和青少年运动员腰椎上部应力性损伤的潜在危险因素。研究设计： 横断面研究;证据水平， 3.方法： 回顾了 2 个学术医疗中心 （2016年7月至 2021年6月） 902 例诊断为症状性椎弓根和关节间部应激损伤的儿科和青少年运动员 （364 例女性，538 例男性;平均年龄 14.5 ± 2.1 岁） 的病历。所有患者在诊断时都接受了 MRI。仅纳入 MRI 上 pars/ridicle 水肿的患者。分析了 5 年期间有关单一运动专业化、运动参与、生物力学运动类别（轴向旋转与伸展/轴向负荷）和椎体损伤水平的数据。应激反应或活动性脊柱分离症 （SRAS） 是根据 MRI 上改编的 Hollenberg 分类系统用于指定 1 级、2a 级或 3 级应力损伤的术语。上层椎骨定义为 L3 或上椎骨，而下层椎骨包括 L4 或下椎骨。结果： 在 902 例 SRAS 损伤患者中，大多数 （n = 753 [83.5%]） 完全是单级低应力损伤，而 67 例 （7.4%） 是多级应力损伤。有 82 名运动员 （9.1%） 患有单水平上应力损伤。 患有上水平 pars/椎弓根应力损伤的运动员在诊断时年龄较大 （分别为 15.8 ± 1.9 对 14.3 ± 2.1 岁;P < .001），就诊前腰痛持续时间较短 （分别为 2.50 ± 2.70 vs 4.14 ± 6.73 个月;P < .001），更有可能专注于一项运动（分别为 43.9% 和 32.3%;P = .046），诊断时 MRI 上活动性脊椎分离症的发生率较低 （分别为 42.7% 和 59.8%;P = .004） 与压力损伤水平较低的运动员相比。与多项运动运动员相比，专门从事一项运动的腰椎应力损伤运动员上层参与的几率几乎是其两倍（调整比值比，1.80 [95% CI，1.06-3.04];P = .03）。诊断时 MRI 上存在活动性脊柱溶解症的运动员上层受累的几率几乎是上层受累的一半（校正比值比，0.55 [95% CI，0.33-0.91];P = .02）。结论： 诊断时年龄、腰痛持续时间、单一运动专业化以及诊断时 MRI 上是否存在活动性脊柱溶解是运动员腰椎应激损伤被归类为上层或下部受累的主要预测因子。总体而言，多变量分析中包含的变量是适度的预测因子，仅解释了按脊柱水平分类的腰骶部应力损伤发生率方差的 15.1%。这些特定的生物力学因素和导致这些发现的其他潜在因素值得进一步研究。