To determine the incidence of resorption after anterior lumbar interbody fusion (ALIF) and its effect on outcome.
Recombinant human bone morphogenetic protein-2 (rhBMP-2) used in ALIF has been associated with a 0.5% to 82% incidence of resorption. This has been described as either a complication or part of the natural history. We postulate that early resorption (≤4 mo) in ALIF using femoral ring allograft augmented with rhBMP-2 supplemented with posterior instrumentation has no effect on outcome.
Institutional review board–approved retrospective 60 chart cohort study of ALIF using femoral ring allograft–augmented rhBMP-2 supplemented with posterior instrumentation from May 5, 2005, to April 6, 2010. Two groups were based upon the presence or absence of early graft resorption (≤4 mo). Patients were seen prior to surgery and postoperatively until 29 ± 20 months (last visit). Follow-up visual analogue scale pain scores and radiographical evidence of fusion were measured and compared between the 2 groups.
Sixty patients, 27 females and 33 males had follow-up for 29 ± 20 months. Group 1 (33 patients, 45 levels) and group 2 (27 patients, 36 levels) were identical in age (P = 0.62), sex distribution (P = 0.43), preoperative pain score (P = 0.63), and in the rhBMP-2 dose per level (P = 0.77). There were no significant group differences in postoperative visual analogue scale scores but a trend to higher fusion rate in group 1 was seen (P = 0.07) at 6 months. There was a 40% incidence of early resorption with no significant differences in visual analogue scale scores or fusion rate between both groups.
There is a 40% incidence of early resorption (≤4 mo) that had no significant effect on pain score or fusion rate. Resorption should be considered part of the fusion process and not necessarily a complication.
Level of Evidence: 3
Retrospective 60 chart cohort with early (n = 33) versus no resorption (n = 27) groups identical in age (P = 0.62), sex distribution (P = 0.43), preoperative pain (P = 0.63), and recombinant human bone morphogenetic protein-2 dose (P = 0.77). There was 40% early resorption that had no significant effect on visual analogue scale score or fusion rate.
*Department of Orthopaedics, Cleveland Clinic, Cleveland, OH; and
†Center for Spine Health, Lutheran Hospital, Cleveland, OH.
Address correspondence and reprint requests to Mark Kayanja, MD, PhD, CORE Institute, 18444 N 25th Avenue, Phoenix, AZ 85023; E-mail: email@example.com
Acknowledgment date: March 4, 2013. Revision date: September 26, 2013. Acceptance date: November 18, 2013.
The device(s)/drug(s) that is/are the subject of this manuscript is/are not FDA-approved for this indication and is/are not commercially available in the United States.
No funds were received in support of this work.
Relevant financial activities outside the submitted work: consultancy, employment, patents, travel/accommodations/meeting expenses.