Injury, Int. J. Care Injured 40 (2009) S3, S62–S66 Contents lists available at ScienceDirect Injury journal homepage: www.elsevier.com/locate/injury Use of bone morphogenetic proteins in arthrodesis: Clinical results Nikolaos K. Kanakaris a , Ravi Mallina a , Giorgio M. Calori b , George Kontakis a , Peter V. Giannoudis a, * a Department of Trauma and Orthopaedics, Leeds Teaching Hospitals NHS Trust, Great George Street, Leeds LS1 3EX, UK b Department of Trauma and Orthopaedic Surgery, Instituto Ortopedico Gaetano Pini, Milan University, Italy article info Keywords: Arthrodesis Fusion Bone morphogenetic proteins BMP-7 Grafting abstract Bone grafting is not routinely required in primary arthrodesis in the absence of infection, avascular necrosis, bone defect or previous non-union; when any of the above factors is present, autograft is the gold-standard method. However, donor site morbidity and the quantitative and qualitative limitations of autograft have led to the development of alternatives. This study documents the use of the bone morphogenetic protein BMP-7 in a total of 19 joint fusions (ankle, subtalar, talonavicular, pubic and sacroiliac). Healing rates of 90% and satisfactory subjective functional outcome in 70% of cases were recorded over a minimum follow-up of 15 months. These data should provide a sound foundation for future clinical trials evaluating the application of BMP-7 in the fusion of joints. © 2009 Elsevier Ltd. All rights reserved. Introduction Arthrodesis was widely practised before the era of arthroplas- ties and the contemporary advances in the management of intraarticular fractures and osseo-cartilaginous pathology. Currently arthrodesis still represents the ultimate in spine and pelvic girdle surgery, is a reliable method of surgical management of the small joints of the extremities and, for the large joints of the upper and lower extremities, is a salvage or last-resort option. 1,14,27,33–35,44,53 The existing methods of achieving a successful arthrodesis vary according to the anatomical site, the underlying pathology, the presence or absence of previous implants, and the condition of the surrounding soft-tissue envelope. The basic principles are, however, the same and consist of debridement of the articular cartilage, preservation of adequate bone stock and stable compressive fixation in a position that permits optimal function of the fused extremity. 23,38–41,44 Bone grafting is used as an osteoinductive and osteogenic stimulus in cases of suboptimal local or systemic biology, in failed attempted fusions and revisions and in the presence of large defects after debridement requiring an active void filler. The different grafting options described in the literature include autologous bone graft from the pelvis or adjacent anatomical sites, allografts, bone substitutes or their combinations. 42,43,52 Bone morphogenic proteins (BMPs) emerged during the past 15 years and, since recombinant technology achieved their biosynthesis, have been applied and have proved their potency as osteoinductive agents in cases of acute fracture, 29,50 long- bone non-union 9,18,32 and spinal fusion. 26,36 Of these proteins, currently BMP-2 and BMP-7 are commercially available, and ample * Corresponding author. Tel.: +44 (0) 113 392 2750; fax: +44 (0) 113 392 3290. E-mail address: pgiannoudi@aol.com (P. Giannoudis). evidence has been collected during the past decade regarding their approved indications 3,4,9,15,21,28 and their off-licence use. 8,11,18–20,29,48 Different authors have described the application of these BMPs in achieving a successful arthrodesis in different anatomical sites, 19,20 extrapolating the experience gained from the spinal fusions. In this study we present our experience over a period of 4 years with the administration of BMPs to a series of people undergoing arthrodesis of the appendicular skeleton or fusion of the pelvic girdle joints. Materials and methods A prospectively created database of the BMP-7 applications at our institution was used to identify cases of arthrodesis. The existing database includes demographics, previous medical history, comorbidities, intraoperative and in-hospital details of each person and also data expanding to the whole follow-up period until successful bone healing and discharge of the person from the outpatient clinic. The indications for arthrodesis were posttraumatic arthritis and chronic pain, chronic postpartum pelvic girdle pain and septic destructive arthritis. The indications for the off-licence BMP-7 application at the surgeon’s discretion included previous failed attempts (nine cases) and the presence of risk factors for impaired bone healing such as tobacco use, diabetes mellitus, chronic corticosteroid therapy and poor local biology. All the cases included in the study were treated with local application of BMP-7 (OP-1 ® , Osigraft ® ; Stryker-Biotech, Hopkinton, MA), a combination of 3.5 mg rhBMP-7 with 1 g purified type I bovine collagen as a carrier. The product is reconstituted with saline to form a paste, which is then implanted at the fusion site. BMP-7 was used as a substitute for autologous bone graft in eight cases. In the other 11 cases, where the defect was greater than 2cm, BMP-7 was used in conjunction with autologous bone grafting or allograft. 0020-1383/ $ – see front matter © 2009 Elsevier Ltd. All rights reserved.