Single-blinded prospective randomized study comparing open versus needle technique for obtaining autologous cancellous bone from the iliac crest

One of the most frequent complications of cervical anterior discectomy with fusion is pain at the donor site, usually the iliac crest. Despite the advent of new materials, autologous bone is still the "gold standard" for fusion procedures. A prospective, single blinded, randomized study was performed to evaluate the effect of a minimal invasive technique to obtain autologous bone from the iliac crest on pain. The minimal invasive technique uses a large needle to obtain cancellous bone. Consecutive patients scheduled for cervical anterior discectomy with a fusion using a cage were randomly assigned either to the classical open group or the needle group. Patients were unaware of the two possible options for obtaining autologous bone. They were asked to fill in visual analogue scores (VASs) at fixed moments during the first 6 weeks postoperatively. Three VASs were recorded: the score at the moment, the minimal score and the maximal score during the last 24 h. The wound at the iliac crest was measured 6 weeks postoperatively. Complications were registered. Fifty patients were enrolled. Twenty-five patients were assigned to each group. The pain scores from the needle group were significantly less than from the open group. At 2 weeks postoperatively, nearly all patients (88%) of the needle group were free of pain at the iliac crest, whereas ten patients (40%) of the open group still had some pain. Complications only occurred in the open group. Six patients complained of diminished sensibility. In two cases, it had resolved at 6 weeks postoperatively. In one case, a hemorrhage occurred. Surgical evacuation was not necessary. Obtaining autologous cancellous bone through a large needle for filling a cervical cage (even multiple cages) is safe and evidently less painful than through a classical open procedure. If pain exists it does not last very long. Generally, the pain is resolved within 2 weeks.