This Swedish multicenter RCT randomized 222 patients with therapy-resistant chronic low back pain (at least 2 years, L4–S1 degeneration) to three lumbar fusion constructs. The three groups were: posterolateral fusion alone, posterolateral with pedicle screws, and circumferential (360°) fusion. The primary question was whether more complex constructs produce better clinical outcomes.
The intuitive assumption going into the 1990s was that more rigid, more comprehensive constructs should produce better outcomes — circumferential fusion maximizes stability and graft surface area, so it should work better. This study showed that assumption was wrong for clinical outcomes, even as it confirmed the biomechanical expectation that instrumentation improves fusion rates.
When choosing a fusion technique for a patient with chronic low back pain, the operative decision should favor the least complex construct that achieves your goals. Posterolateral fusion without instrumentation matched instrumented and circumferential approaches on every clinical measure while carrying a fraction of the complication burden.
Counsel patients that 60–68% can expect meaningful improvement, but fusion is not a cure. Return-to-work is around 35% regardless of technique. This paper is why adding instrumentation to a straightforward fusion requires a specific justification beyond simply wanting a higher fusion rate.
This Swedish multicenter RCT randomized 222 patients with therapy-resistant chronic low back pain (at least 2 years, L4–S1 degeneration) to three lumbar fusion constructs. The three groups were: posterolateral fusion alone, posterolateral with pedicle screws, and circumferential (360°) fusion. The primary question was whether more complex constructs produce better clinical outcomes.
The intuitive assumption going into the 1990s was that more rigid, more comprehensive constructs should produce better outcomes — circumferential fusion maximizes stability and graft surface area, so it should work better. This study showed that assumption was wrong for clinical outcomes, even as it confirmed the biomechanical expectation that instrumentation improves fusion rates.
When choosing a fusion technique for a patient with chronic low back pain, the operative decision should favor the least complex construct that achieves your goals. Posterolateral fusion without instrumentation matched instrumented and circumferential approaches on every clinical measure while carrying a fraction of the complication burden.
Counsel patients that 60–68% can expect meaningful improvement, but fusion is not a cure. Return-to-work is around 35% regardless of technique. This paper is why adding instrumentation to a straightforward fusion requires a specific justification beyond simply wanting a higher fusion rate.