ORIGINAL PAPER Fusion rate and clinical outcome in anterior lumbar interbody fusion with beta-tricalcium phosphate and bone marrow aspirate as a bone graft substitute. A prospective clinical study in fifty patients Ricarda Lechner 1 & David Putzer 2 & Michael Liebensteiner 1 & Christian Bach 3 & Martin Thaler 1 Received: 11 July 2016 /Accepted: 15 September 2016 # SICOT aisbl 2016 Abstract Purpose Bone graft substitutes have been successfully used in posterolateral lumbar fusion, anterior cervical fusion and ani- mal studies. This study has been conducted to assess the safety and efficacy of β-tricalcium phosphate (β-TCP) in instru- mented anterior lumbar interbody fusion (ALIF) procedure. Methods In a prospective clinical study, ALIF cages were pre- filled with β-TCP and additionally fixated with posterior ped- icle screw. Computed tomography (CT) and X-rays were per- formed one year after surgery. Fusion was assessed and func- tional status was evaluated before and one year after surgery. Results X-ray evaluation showed a definite fusion in 85.48 % of treated levels. CT assessment showed anterior and posterior intersegemental bone bridging in 77.78 % of treated levels. Conclusions The X-ray fusion rate presented is comparable with those published for ALIF procedures with bone graft. Fusion rates β-TCP are similar to autologous bone. ALIF with β-TCP and additional posterior fixation is a safe and effective procedure. Keywords Anterior lumbar interbody fusion . Bone graft substitute . Bone marrow aspirate . Calcium phosphate . Donor site complication Introduction For decades autologous iliac crest bone grafting has been the Bgold standard^ in anterior lumbar interbody fusion (ALIF) [1]. However, iliac bone harvesting is associated with donor site pain, haematoma, infection, fracture of the ilium, sensory disturbance and cosmetic impairment [2]. These complica- tions caused by bone graft harvesting can result in disability and thus increase the recovery time and patient care costs. In addition, studies have shown a 100 % loss of disc space height after ALIF procedures with femoral allograft, and 46 % of the treated levels end up with a lower disc height than pre- operatively [3]. Nowadays, anterior intervertebral body cages, whether stand-alone or combined with posterior fixation, have become one of the standard operative remedies for degenera- tive disorders of the lumbar spine [4]. Recently, published studies have shown sufficient restoration of lumbar lordosis, a significant improvement in intervertebral height and radio- logical evidence of fusion in 98.6 % of all patients treated with ALIF cages [4]. However, these cages have to be filled with a large amount of bone graft in order to achieve fusion. As an alternative to autologous bone graft, new technologies have been introduced, including allograft, ceramics, demineralised bone matrix, osteoinductive factors, autogenous platelet con- centrate, mesenchymal stem cells and gene therapy. Although these products show good results in experimental trials, their usage is limited by the high cost of the products, their avail- ability outside countries with high standards of medical care and an unsatisfactory number of published clinical trials. Of these graft substitutes, calcium phosphate ceramic is one of the most commonly used [5, 6]. Porous β-tricalcium phosphate (β-TCP) is biocompatible and osteoconductive, but not very osteoinductive. Therefore, biologically active tissues, like bone marrow aspirate, are recommended for use with β- * Martin Thaler martin.thaler@i-med.ac.at 1 Department of Orthopaedic Surgery, Medical University Innsbruck, Anichstr. 35, 6020 Innsbruck, Austria 2 Department of Orthopaedic Surgery-Experimental Orthopaedics, Medical University Innsbruck, Innrain 36, 6020 Innsbruck, Austria 3 Department of Orthopaedic Surgery, Landeskrankenhaus Feldkirch, Carinagasse 47, 6807 Feldkirch, Austria International Orthopaedics (SICOT) DOI 10.1007/s00264-016-3297-x