Five-year follow-up of total disc replacement compared to fusion: a randomized controlled trial.

PURPOSE

To evaluate long-term clinical results of lumbar total disc replacement (TDR) compared with posterior lumbar fusion.

METHODS

This prospective randomized controlled trial comprised 152 patients; 80 were randomized to TDR and 72 to fusion. All patients had chronic low back pain (CLBP) and had not responded to nonsurgical treatment. Primary outcome measure was global assessment of back pain (GA), secondary outcome measures were back and leg pain, Oswestry Disability Index (ODI), EQ5D, and SF-36. All measures were collected from SweSpine (Swedish national register for spinal surgery) at 1, 2, and 5 years. Follow-up rate at 5 years was 99.3 %.

RESULTS

Both groups showed clinical improvement at 5-year follow-up. For GA, 38 % (30/80) in the TDR group were totally pain free vs. 15 % (11/71) in the fusion group (p < 0.003). Back pain and improvement of back pain were better in the TDR group: VAS back pain at 5 years 23 ± 29 vs. 31 ± 27, p = 0.009, and VAS improvement of back pain at 5 years 40 ± 32 vs. 28 ± 32, p = 0.022. ODI and improvement in ODI were also better in the TDR group: ODI at 5 years 17 ± 19 vs. 23 + 17, p = 0.02 and ODI improvement at 5 years 25 ± 18 vs. 18 ± 19 (p = 0.02). There was no difference in complications and reoperations between the two groups.

CONCLUSIONS

Global assessment of low back pain differed between the two surgical groups at all follow-up occasions. Significant differences between groups concerning back pain, pain improvement, and ODI were present at 1 year and disappeared at 2 years, but reappeared at the 5-year follow-up.