Efficacy of autologous growth factors in lumbar intertransverse fusions

A retrospective, consecutive series with "blinded" radiographic review was performed to evaluate two groups undergoing lumbar fusion: one with and one without autologous growth factors (AGF).

AGF has been shown to promote bone formation in vitro and in vivo in animal studies. Accordingly, it has been promoted to augment lumbar intertransverse fusions. To date, however, no controlled studies have been performed to assess its ability to do so in humans. This article presents the first such study.

Two groups were studied. The control group consisted of 27 consecutive patients who underwent a single-level intertransverse lumbar fusion using iliac crest bone graft for either degenerative disk disease (DDD) or degenerative spondylolisthesis from January 1999 to November 1999. The AGF group consisted of 32 consecutive patients undergoing an identical procedure for the same indications with iliac crest bone graft augmented with AGF from January 2000 to November 2000. Fusions were assessed radiographically at 1 and 2 years by two independent spine surgeons on AP and lateral flexion/extension radiographs.

The fusion rate for the control group was 24 of 27, or 91%. The fusion rate for the AGF group was 18 of 32 or 62%.

In this study, the use of AGF resulted in inferior rates of arthrodesis compared with autogenous bone graft alone. Although it is important to note there are several techniques available to produce AGF and that the concentration of AGF may differ between individuals, based on the authors' findings, they cannot recommend the use of AGF for this indication until further clinical studies, perhaps altering these variables, prove otherwise.