Rare lumbar disc injuries can follow low-energy trauma, study finds

A clinical and crash-database study reports that traumatic lumbar disc injuries are rare but can occur after relatively minor events, including falls from standing height and low-speed motor-vehicle collisions. Researchers at Jena University Hospital reviewed 33 patients treated between 2007 and 2024 and compared them with 10 occupants identified in the National Highway Traffic Safety Administration crash database. Every patient in the hospital series had at least one accompanying spinal injury, while two occupants in the crash database were recorded with no injury apart from a lumbar disc lesion. Because the database cases lacked detailed imaging and medical records, the authors cautioned that their apparent isolation could reflect imperfect injury documentation rather than a genuinely isolated disc injury.

The hospital series included five patients injured in minor falls from standing height, 14 who fell from greater heights, five who were struck by heavy objects, and six involved in road traffic accidents. Patients in the accident cases had a mean age of 53 years, with a standard deviation of 18.7 years. The upper lumbar levels were most commonly affected: 23% of injuries involved L1 and another 23% involved L2. Most of the patients, 66%, had no documented spinal degeneration. Several of the patients injured in low-energy falls, however, were older or had relevant pre-existing conditions, including osteoporosis and Bechterew’s disease, potentially making their spines more susceptible to injury. The mean Injury Severity Score in the hospital group was 16, with a standard deviation of 10.3, and individual scores ranged from 4 to 43.

Re-examination of radiographs, MRI scans and CT scans by a neuroradiologist identified acute trauma-related findings in every hospital case. Thirty-one of the 33 patients, or 94%, had a vertebral fracture adjacent to the injured disc. Most of these fractures were type A injuries under the AO classification, indicating compression injury; one patient had a type B fracture and two had type C fractures, while six had fractures assigned to more than one type. In the two patients without adjacent fractures, the fractures were located at L1 even though the injured discs were lower in the lumbar spine. Rupture of the anterior or posterior longitudinal ligament, or spinal haematoma, was found in 15 cases. These accompanying abnormalities strengthened the evidence that the disc lesions arose from trauma, although the records did not permit reconstruction of the precise loading forces in each case.

Neurological symptoms were documented in 15 patients, including radiating pain consistent with radiculopathy in six, even though the exact frequency of disc-related neurological impairment could not be established. Seventeen injured discs were considered neurologically asymptomatic, and one patient had no documented pain or neurological deficit. The investigators noted that asymptomatic herniated discs are known to occur and that clinical data linking specific symptoms to traumatic disc lesions were limited. The overall pattern nevertheless associated most hospital cases with substantial injury: 57.6% had Injury Severity Scores in the moderate-to-severe range, and all five patients with scores of 30 or higher had sustained high-energy accidents. These observations describe the severity and accompanying findings in this selected hospital population rather than the probability of disc injury for the general population.

The NHTSA analysis produced a contrasting picture. Among 42,706 occupants represented in the selected 2017–2023 crash data, only 10 were recorded with a traumatic lumbar disc injury, and change in vehicle velocity was available for six. The documented velocity changes ranged from 9 to 71 km/h, with a mean of 29 km/h. Four crashes were frontal, three were rear-end, and three involved side, mixed or unknown collision directions. Two occupants had no reported injuries other than the disc injury. One was a 26-year-old driver with an L3 disc herniation and nerve-root damage following a rear-end and then frontal collision, for which no velocity change was recorded. The other was a 27-year-old driver who sustained a disc herniation without nerve-root damage in a side impact at 9 km/h; the database attributed the injury to lap-shoulder belt contact, although the airbag did not deploy and the seat showed no accident-related damage.

Three database cases with known velocity changes involved values below 20 km/h. One 58-year-old driver sustained a disc injury during a rear-end collision at 18 km/h, with the database describing a forceful recoil against the seatback; her Injury Severity Score was 5. In another case, an unbelted 38-year-old driver with obesity sustained an L4 disc herniation in a frontal collision at 16 km/h, during which the steering wheel was plastically deformed. A 14 km/h frontal impact injured a belted front passenger who had both lumbar disc herniation and L2 and L3 vertebral fractures. These records suggest possible low-speed mechanisms, but the study stressed that crash documentation can misidentify the event responsible for an injury. Detailed radiology was unavailable for the NHTSA cases, preventing independent verification that the recorded disc lesions were traumatic and that the assigned collision or restraint mechanism was correct.

An exploratory comparison using an illustrative 30 km/h cut-off estimated the probability of a documented disc injury at 0.000709 for occupants with velocity changes at or below 30 km/h and 0.005948 for those above that value. The corresponding relative risk for the higher-velocity group was 8.35, with a 95% confidence interval of 3.54 to 19.90. These estimates came from very few disc-injury cases and were expressly described as exploratory rather than a basis for an injury threshold. The analysis also used a broader set that included cervical and thoracic disc injuries, leaving 21 cases with known velocity changes and 18,444 without a recorded disc injury. Change in vehicle velocity was also only one component of crash severity and did not directly measure the load transmitted to the spine.

Biomechanically, the hospital data support compression as an important component of many injuries because most adjacent fractures were classified as type A compression fractures. Earlier experimental work cited by the study had linked combined lumbar flexion and rapid axial compression with disc herniation, while animal experiments likewise associated flexion-compression loading with disc damage. The magnitude and rate of the load may influence the outcome. The hospital evidence cannot, however, establish the exact mechanism in individual patients, and the review notes disagreement over whether one traumatic event can produce a clinically relevant isolated disc injury without other damage. Reports and laboratory studies describe such isolated lesions, while some experiments found vertebral fracture before herniation, indicating that the sequence can depend on loading conditions and tissue properties.

The study’s principal limitation is the small and heterogeneous evidence base. The hospital series comprised 33 patients and the crash series only 10, making reliable inferential analysis inappropriate. Clinical records provided detailed information about injuries but little direct information about biomechanical loading, and patient accounts of events can be biased. NHTSA records offered crash variables such as velocity change and collision type but lacked the imaging and medical documentation needed to validate the diagnoses or reconstruct spinal loading. The authors therefore concluded that traumatic lumbar disc injury can follow low-energy events, especially in people with susceptibility from age or pre-existing spinal disease, but that every hospital case also had another spinal injury. The apparent isolated database cases require caution because the limitations of rare-injury coding and incomplete verification leave their traumatic origin uncertain.

Subject of Research: Radiologic and biomechanical evidence on traumatic lumbar disc injury following low- and high-energy trauma

Article Title: Traumatic lumbar disc injury – radiology and biomechanics

Article References: Rautenberg, A., Eckardt, N., Streng, J., Schwarz, F., Wilharm, A., Hubig, M., & Muggenthaler, H. (2026). Traumatic lumbar disc injury – radiology and biomechanics. International Journal of Legal Medicine. https://doi.org/10.1007/s00414-026-04051-1

Image Credits: AI Generated

DOI: 10.1007/s00414-026-04051-1

Keywords: lumbar disc injury, spinal trauma, low-energy trauma, motor vehicle crashes, MRI, vertebral fractures, flexion-compression, injury severity, NHTSA database, Traumatic, lumbar, disc