From the Guidelines
Artificial disc replacement is associated with significant caveats regarding its long-term benefits and harms, including limited data on its effectiveness for multi-level disk disease and potential surgical complications, as reported in a 2021 umbrella review of level 1 evidence published in the BMJ 1. The effectiveness of artificial disc replacement is influenced by several factors, including the type of disc disease, the level of disk involvement, and the surgical approach used.
- The 2021 review found that total disc replacement significantly improved pain and patient satisfaction, reduced reoperation rate and operation time, shortened duration of hospital admission, and decreased post-surgical complications compared with lumbar spine fusion in both the short term and the long term 1.
- However, the review also noted that the results were variable in earlier reviews, and that newer randomised controlled trials were necessary to fully assess the long-term benefits and harms of artificial disc replacement 1.
- Additionally, the review highlighted the importance of considering the minimally invasive approach, which was associated with less blood loss, shorter hospital stay, and slightly less disability compared with open transforaminal lumbar interbody fusion for single level degenerative disease 1.
- The lack of randomised controlled trials comparing lumbar spine fusion with no treatment, placebo, or sham surgery is a significant limitation, and clinicians should exercise caution when evaluating the risk-benefit profile of artificial disc replacement compared to alternatives like spinal fusion or conservative management 1.
- Patients considering artificial disc replacement should be informed of these limitations and caveats during the consent process, and clinicians should carefully weigh the potential benefits and harms of this intervention based on the best available evidence 1.
From the Research
Long-term Benefits and Harms of Artificial Disc Replacement
The effectiveness of artificial disc replacement (ADR) in terms of long-term benefits and harms is a topic of ongoing research and debate. Several studies have investigated the outcomes of ADR compared to fusion surgery for degenerative disc disease.
- Preservation of Motion: A study published in 2014 2 found that ADR can preserve the motion of the spinal unit in young patients, with 73% of segments maintaining motion at an average follow-up of 30 years.
- Adjacent Segment Degeneration: However, the same study noted that whether ADR can prevent adjacent segment degeneration requires further investigation. Another study published in 2021 3 highlighted the limitations of ADR in treating multilevel disc disease, citing the need for further research on its clinical safety and efficacy.
- Comparison to Fusion: A meta-analysis published in 2010 4 found that ADR does not show significant superiority over fusion for the treatment of lumbar degenerative disc disease, with similar outcomes and complication rates at 2 and 5 years. Similarly, a study published in 2019 5 found no significant difference in outcomes between ADR and fusion for cervical degenerative disc disease with radiculopathy at 5 years.
- Safety and Efficacy: A meta-analysis published in 2014 6 found that ADR is more effective than fusion in terms of improved physical function, reduced pain, and shorter duration of hospitalization, with comparable safety and efficacy at 2-year follow-up. However, the benefits of motion preservation and long-term complications are still unclear.
Caveats and Limitations
The current evidence on ADR highlights several caveats and limitations, including:
- Limited Long-term Follow-up: Many studies have limited long-term follow-up, making it difficult to draw conclusions about the durability and safety of ADR.
- Variability in Study Designs: The variability in study designs, patient populations, and outcome measures makes it challenging to compare and pool results across studies.
- Need for Further Research: Further research is needed to fully understand the benefits and risks of ADR, particularly in terms of motion preservation, adjacent segment degeneration, and long-term complications.