From the Research
Pilots with 2-level cervical disc arthroplasty should be restricted to non-ejection seat aircraft or face medical disqualification due to the significant forces experienced during ejection, which could potentially cause catastrophic failure of the implants, leading to spinal cord injury or device displacement. The concern stems from the significant forces experienced during ejection (up to 20G), which could potentially cause catastrophic failure of the implants, leading to spinal cord injury or device displacement, as highlighted in a study on polytrauma in a jet pilot after low-altitude ejection without parachute deployment 1. The titanium and polyethylene components of artificial discs have not been thoroughly tested under such extreme acceleration forces. Additionally, the altered biomechanics of the spine after arthroplasty may increase vulnerability to injury during high-G maneuvers.
Some studies have compared the outcomes of cervical disc arthroplasty and anterior cervical fusion, showing similar clinical outcomes and adverse events between the two groups 2, 3. However, these studies do not specifically address the safety of 2-level cervical disc arthroplasty in pilots who operate ejection seats. A more recent study on two-level anterior cervical discectomy and fusion versus cervical disc arthroplasty provides long-term evidence update, but still does not address the specific concern of ejection seat pilots 3.
Given the lack of specific data on the safety of 2-level cervical disc arthroplasty for pilots who operate ejection seats, and considering the potential risks associated with ejection, it is recommended that pilots with this condition consult with both their neurosurgeon and aviation medical examiner to determine the best course of action. Policies vary between military branches and civil aviation authorities, and individual waivers are sometimes considered based on specific circumstances.
Key points to consider:
- The significant forces experienced during ejection (up to 20G) could potentially cause catastrophic failure of the implants, leading to spinal cord injury or device displacement.
- The altered biomechanics of the spine after arthroplasty may increase vulnerability to injury during high-G maneuvers.
- Pilots with cervical disc arthroplasty would likely be restricted to non-ejection seat aircraft or face medical disqualification.
- Individual waivers are sometimes considered based on specific circumstances, and pilots should consult with both their neurosurgeon and aviation medical examiner to determine the best course of action.