Injury, Int. J. Care Injured 45S5 (2014) S7–S13 Introduction The treatment of non-union is a challenge to orthopaedic surgeons even with the on-going increase in knowledge of the mechanisms of fracture healing [1-7]. In the United States, an estimated 5 to 10% of the 6.2 million fractures that occur annually are associated with an impaired fracture healing response and develop delayed union or non-union [8,9]. All stages of the bone repair process require the interaction of cells and biologically active molecules [10-12]. Mechanical stability and vascular integrity at the fracture site are also important parameters that contribute to the healing response [13]. Excessive motion that causes mechanical instability at the fracture site, and impaired blood supply due to damage to nutrient vessels, have a direct influence on the development of non-union [13,14]. Giannoudis et al. [15] have also demonstrated a striking correlation between the use of pharmacological agents such as NSAIDs for longer than four weeks, and the incidence of non-union of the femoral diaphysis. Femoral shaft fractures are common in young adults and result from high-energy trauma caused by motor vehicle accidents, falls from a height and gunshot injuries. The method of choice for fixation of this type of fracture is locked intramedullary nailing with the aim to recover length, alignment, and rotation to the femur [16]. Non-union after femoral nailing was not a common finding in early reports [17]; however, the increased use of intramedullary nailing for the treatment of femoral shaft fractures has been associated with rates of non-union as high as 13.6%, and improved survival of severely injured patients [18]. In a series of 278 patients (280 fresh femoral shaft fractures) treated with intramedullary nailing, more than one-tenth of the patients required additional surgery for failed consolidation [19]. Failed union of the femoral shaft after nailing is a serious complication and is difficult to treat [20,21]. KEYWORDS Bone marrow grafting Femoral shaft fracture Intramedullary nailing Fracture healing Non-union ABSTRACT The aim of this study was to assess the union rates in a series of patients with failed femoral shaft aseptic non-union who were treated with percutaneous concentrated autologous bone marrow grafting. Bone marrow harvesting and cell injection were performed under general anaesthesia in a single surgical procedure. Radiographic union was diagnosed in fractures with a score ≥10 according to the radiographic union scale in tibial fractures (RUST) and confirmed by clinical examination. Eight out of 16 patients progressed to consolidation (RUST score ≥10). Radiographic evidence of fracture union was observed at an average of 4.75±1.75 months (range 3 to 8 months). All eight patients who did not progress to union within 12 months following the cell grafting procedure had a RUST score ≤10 (range 4 to 9). There were no differences in age, number of previous surgeries, duration of non- union and preoperative RUST score between the patients that developed solid union and those with failed consolidation. However, a relationship between the number of osteoprogenitors injected and the rate of union was noted, 20.2±8.6 × 10 8 versus 9.8±4.3 × 10 8 , p<0.005, between the patients with and without union, respectively. The efficacy of percutaneous autologous concentrated bone marrow grafting seems to be related to the number of osteoprogenitors available in the aspirates. Optimisation of the aspiration technique and concentration process is of paramount importance to increase the incidence of a successful outcome. © 2014 Elsevier Ltd. All rights reserved. The effect of autologous concentrated bone-marrow grafting on the healing of femoral shaft non-unions after locked intramedullary nailing João Antonio Matheus Guimarães a, *, Maria Eugenia L Duarte a , Marco B Cury Fernandes a , Verônica F Vianna a , Tito H N Rocha a , Danielle C Bonfim a , Priscila L Casado a , Isabel C C do Val Guimarães b , Luis G Coca Velarde c , Hélio S Dutra d , Peter V. Giannoudis e a National Institute of Traumatology and Orthopaedics, Rio de Janeiro, Brazil b School of Medicine, Fluminense Federal University, Rio de Janeiro, Brazil c Epidemiology and Biostatistics, Fluminense Federal University, Rio de Janeiro, Brazil d Institute of Health Sciences, Federal University of Rio de Janeiro, Brazil e School of Medicine, University of Leeds, Leeds, UK; Leeds Biomedical Research Unit, Chapel Allerton Hospital, Leeds, UK * Corresponding author at: Instituto Nacional de Traumatologia e Ortopedia (INTO), Avenida Brasil 500, São Cristóvão, 20940-070, Rio de Janeiro, RJ, Brazil. Tel.: 55-21-2134-5102; fax: 55-21-2135-5089. E-mail addresses: jomatheus@uol.com.br, jguimaraes@into.saude.gov.br (J.A. Matheus Guimarães). 0020-1383/$ – see front matter © 2014 Elsevier Ltd. All rights reserved. Contents lists available at SciVerse ScienceDirect Injury journal homepage: www.elsevier.com/locate/injury