Rigid Collar or no Collar for Non-surgical Treatment of Stable Cervical Spine Fractures: a Protocol for a Randomized Register Trial

The annual incidence rate of spinal fracture is 64 per 100,000 with a peak in young men and elderly women (1). Ten percent of all traumatic spinal fractures are located in the upper cervical spine and 20% in the subaxial cervical spine (2). Stable cervical spine fractures are treated non-surgically, with a rigid collar that is worn 24 hours a day for 12 weeks to limit neck movements and promote bone healing. However, rigid collars only restrict 40-50% of cervical spine motions (3, 4). The drawbacks with collar treatment are that the collar may be very uncomfortable, may cause pressure ulcer, or affect swallowing or breathing (5). Wearing a collar is associated with difficulties to perform activities of daily living due to the limited neck movement. Treatment without a collar would avoid the annoyance and potential harm, whilst the stable fracture may still heal.

Investigators aim to compare the benefit versus the harm and discomfort of rigid collar treatment with treatment without a rigid collar, in a registry based randomized controlled trial.

Treatment decisions may be made using a fracture classification such as the Subaxial injury classification and severity scale (SLICS) (6) or others. C1 and C2 fractures have separate classifications. In C1 fractures a lateral dislocation of > 7 mm is classified as unstable and requires surgical fixation. In the elderly, C2 fractures are common, secondary to low energy trauma and are mostly regarded as stable (7).

Cervical spine fractures are common enough to be a significant public health problem but too uncommon to perform a prospective study comparing the results of current treatments in a single institution. Quality registers are excellent alternatives to close these knowledge gaps. The Swedish fracture register (SFR) is a national register founded in 2011. Spinal fractures have been included since 2015, and the intra- and interrater reliability is acceptable (8). The diagnosing physician classifies the fracture with the help of drawings.

Treatment, non-surgical, or surgical treatment is registered as well as treatment failure, non-surgical treatment converted to surgical stabilization and secondary surgery after failure of the primary surgery. Patient reported outcome measures (PROMs) are sent to the participants shortly after the fracture occurrence (concerning status before the injury), and at one-year of follow-up. The PROMs include the European quality of life 5 dimensions 5 level (EQ-5D-5L) (9) and the Short Musculoskeletal Function Assessment (SMFA) (10). In SFR the treatment failure on cervical spine fractures treated non-surgically is 4% and the most common cause of failure is patients with facet joint dislocation or anterior distraction with posterior compression (manuscript in preparation). However, facet joint dislocation and anterior distraction do not often fall within the recommendations of non-surgical treatment. Investigators consider it to be safe conducting this trial. Investigators expect essentially none of the participants assigned to non-surgical treatment with or without a rigid collar to face the risk of undergoing surgical treatment.