Sports-Related Cervical Spine Fracture and Spinal Cord Injury

A Review of Nationwide Pediatric Trends

Haddy Alas, BS; Katherine E. Pierce, BS; Avery Brown, BS; Cole Bortz, BA; Sara Naessig, BS; Waleed Ahmad, MS; Michael J. Moses, MD; Brooke O'Connell, MS; Constance Maglaras, PhD; Bassel G. Diebo, MD; Carl B. Paulino, MD; Aaron J. Buckland, MBBS, FRACS; Peter G. Passias, MD

Disclosures

Spine. 2021;46(1):22-28. 

In This Article

Discussion

Our study utilized the largest publically available inpatient pediatric database (KID) to describe trends in CSI resulting from youth sports and recreational activities. As >25% of presenting CSIs have been shown to occur secondary to sports, understanding these patterns of injury is an important step in establishing preventative measures. We found that, for children between the ages of 4 and 7, cervical injuries rose from 11.7% in 2003 to 26.9% in 2012, but decreased in pre-adolescents and adolescents. Adolescents had the highest injury rate across all sports, and adolescent age was found to be a significant predictor for upper (C1–4) and subaxial (C5–7) cervical fractures with and without spinal cord injury, cervical dislocation, and cervical SCIWORA. Adolescents also had the highest rate of TBI, and cervical SCIWORA from any sport activity was found to be a significant predictor of concurrent TBI. Water and winter sports were found to be associated with a disproportionately higher rate of upper/lower cervical fracture, while American tackle football injuries were significant predictors of cervical SCIWORA compared to non-football injuries. Targeted prevention strategies at the municipal level may help reduce the potentially devastating burden of these injuries.

Previous studies have detailed the differences in cervical injury patterns between age groups. Poorman et al retrospectively analyzed the KID database for traumatic cervical fracture cases and found that infants and children more frequently fractured C2, whereas adolescents and young adults frequently fractured C7. Interestingly, the study found sports-related cervical fracture to be a significant predictor of SCI and surgical intervention.[18] Other studies have commented on the increased propensity for upper cervical injury in younger children.[5,7,19–21] During physiologic development, the head increases in mass at a rate higher than the rest of the body—resulting in relatively underprepared and underdeveloped neck musculature which may not be able to fully compensate. This introduces a high fulcrum of motion at the cranium and increased risk for cervical injury at the atlanto-occipital and atlanto-axial joints. Hypermobility and incomplete skeletal maturity of the cervical spine have also been shown to increase odds for SCIWORA.[22] Pang et al, in addition to others, initially reported that children under 8 years of age have the highest risk for SCIWORA.[22–25] Although this makes sense from a biomechanical standpoint, other factors must be taken into consideration.

We found that the adolescent age group had the highest rate of cervical spine injury compared to the children and pre-adolescent groups, regardless of type, location, or involvement of spinal cord or brain tissue. Older children and adolescents are more active, mobile, and likely to engage in high-velocity sports than infants and children. The relative benefit of an adolescent's increased musculature and lower head-to-body ratio may be offset by higher energy collisions with more rapid acceleration/deceleration injury to neurologic tissue. Indeed, more recent evidence suggests that the risk for injuries such as SCIWORA increases, not decreases, with age in youth.[26,27]

SCIWORA has been previously associated with sports-related injuries. Although its definition has evolved over time with technological advances in imaging, SCIWORA remains a clinical challenge for patients and practitioners alike. In the present study, cervical SCIWORA (as coded through ICD-9-CM), was defined as spinal cord injury without neuroimaging abnormality on plain films, computed tomography (CT), or magnetic resonance imaging (MRI). A single, level 1 trauma-center study by Brown et al reported an impressively high rate of 75% in kids presenting via sports mechanisms.[7] Although we found a more modest overall rate of 1.59%, we also found adolescent age to be a significant predictor of cervical SCIWORA—increasing odds by 2.75 times compared to children or pre-adolescent age groups. Importantly, cervical SCIWORA was found to co-present with TBI at a disproportionately higher rate (14%) than other cervical injury types, including fracture or dislocation. Patients with cervical SCIWORA had increased odds (2.35×) of presenting with TBI as well, regardless of sport type or age. Compared to all other sports injuries we coded for, American football injuries were specifically found to be predictors of cervical SCIWORA, supporting recent evidence suggesting football-related injuries to be associated with the largest number of severe and catastrophic injuries of any sport.[7,14,28,29]

American football is one of the most popular youth sports played across the United States; however, its style of play allows it to be one of the most dangerous as well. Head-to-head contact is common in football, as is tackling opponents with potential for high velocity head-to-floor or head-to-body contact. Previous studies have shown axial loading of the neck to be one of the most frequently debilitating mechanisms of injury.[5,13] Our data support these findings, with water sports (such as diving and platform diving), winter sports (such as skiing and snowboarding), and football having higher rates of cervical injury compared to other sport modalities. The uniquely destructive injury pattern of these sports may be explained by a dual mechanism involving axial loading (i.e., diving head first or head-to-head contact) and a high velocity of impact (i.e., downhill slopes, platform dive). Rihn et al report a mean incidence of catastrophic neurological injury over the past 30 years to be 0.5 per 10,000 high school football participants. The most common cause reported was forced hyperflexion injury occurring secondary to "spear tackling" another opponent head-on.[30] We reported a rise in cervical spine injuries associated with American football between 2009 and 2012, contrasted with a decrease in cervical spine injuries associated with other sports overall. Strict regulations at the local and state level are necessary to control dangerous maneuvers on the football field, such as spear-tackling, and reduce or eliminate life-threatening spinal cord injury.

Limitations of the present study are shared by any study utilizing the KID database. Codes are typically recorded by trained billing specialists; however, the information may still be limited by human error. The use of ICD-9-CM codes predisposes our data to limited granularity in terms of longitudinal follow-up, long-term outcomes, or inpatient complications. The database lacks information regarding individual procedures and/or surgeries each patient may have undergone which may have changed their course of care. In addition, the KID only gathers information from hospital admissions, excluding patients who may have expired before hospital admission. Future prospective studies delineating risk factors for cervical spine injuries across age groups and sport type would be beneficial in establishing causal relationships.

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