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BACKGROUND: There are ongoing concerns regarding the use of bone graft following prosthetic joint infection and subsequent implant subsidence. The aim of this study was to determine whether the use of a cemented stem combined with femoral impaction bone grafting (FIBG) at second stage revision for infection results in stable femoral stem fixation, determined by accurate methods, and good clinical results. METHODS: A prospective cohort of 29 patients underwent staged revision total hip arthroplasty for infection using an interval prosthesis followed by FIBG at the final reconstruction. The mean follow-up was 89 months (range, 8 to 167 months). Femoral implant subsidence was measured with radiostereometric analysis. Clinical outcomes included the Harris Hip Score, Harris Pain score and Société Internationale de Chirurgie Orthopédique et de Traumatologie activity scores. RESULTS: At 2-years follow-up the median stem subsidence relative to femur was -1.36 mm (range, -0.31 to -4.98), while the cement subsidence relative to femur was -0.05 mm (range, 0.36 to -0.73). At 5-years follow-up, the median stem subsidence relative to femur was -1.89 mm (range, -0.27 to -6.35), while the cement subsidence relative to femur was -0.06 mm (range, 0.44 to -0.55). There were 25 patients who were confirmed infection-free after the second stage revision with FIBG. The median Harris Hip Score improved from 51 pre-operatively to 79 at 5 years (P = .0130), and Harris Pain score from 20 to 40 (P = .0038). CONCLUSIONS: Stable femoral component fixation can be achieved with FIBG when reconstructing the femur after revision for infection without compromising infection cure rates and patient-reported outcomes.
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Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Humanos , Artroplastia de Reemplazo de Cadera/efectos adversos , Artroplastia de Reemplazo de Cadera/métodos , Análisis Radioestereométrico , Prótesis de Cadera/efectos adversos , Estudios de Seguimiento , Trasplante Óseo/métodos , Estudios Prospectivos , Diseño de Prótesis , Fémur/cirugía , Reoperación/métodos , Cementos para Huesos , Dolor/cirugía , Falla de PrótesisRESUMEN
INTRODUCTION: This study aimed to investigate potential factors, including delay to surgical stabilisation, affecting mortality in older patients sustaining pelvic or acetabular (PA) fractures. MATERIALS AND METHODS: A retrospective review of the Trauma Audit and Research Network (TARN) database was performed to identify older patients (aged 65 and over) sustaining PA fractures treated surgically in a UK Major Trauma Centre (MTC) between 2015 and 2019. Chi-squared and Fisher tests were used to compare 1-year mortality rates following operative intervention between patients treated within 72 h and after 72 h. Kaplan-Meier curves were used to visualise survival probability; significant predictors of survival were found using Cox proportional hazard models. RESULTS: Of 564 older patients with PA fractures, 70 met the inclusion criteria. The mean age was 76.1 years. The overall 1-year mortality rate was 20%. When patients were grouped by time to surgery (fracture fixation within or greater than 72 h), there was no statistically significant difference in 1-year mortality. Patients whose surgery was delayed more than 72 h were more likely to have longer hospital stays (p = 0.002) or to have suffered from polytrauma (p = 0.025). Age, Charlson Co-morbidities Index (CCI) and pre-op mobility status were associated with statistically significant differences in overall mortality. The same factors were associated with a significantly increased hazard of death in the multivariate Cox proportional hazards model. Patient gender, mechanism of injury, Injury Severity Score (ISS) > 15 and head injury were not significant predictors of mortality. CONCLUSION: Surgical intervention within 72 h of injury did not result in decreased mortality in older patients with PA fractures. The 1-year mortality rate between older PA fractures and hip fractures was comparable. Consideration should be given to a combined multidisciplinary approach between orthogeriatric and expert PA surgeons for these patients.
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Fracturas Óseas , Fracturas de Cadera , Traumatismo Múltiple , Traumatismos del Cuello , Fracturas de la Columna Vertebral , Anciano , Fijación de Fractura , Fracturas Óseas/cirugía , Humanos , Puntaje de Gravedad del Traumatismo , Estudios RetrospectivosRESUMEN
The clinical presentation of abductor digiti quinti (ADQ) denervation is often non-specific. The diagnosis is generally clinical and may be easily missed. This case report of two patients describes the magnetic resonance imaging (MRI) finding of unilateral oedema and fatty infiltration isolated to the ADQ. A 36-year old woman who presented with laterally located left foot pain was initially diagnosed as having plantar fasciitis. An MRI scan arranged due to the unusual site of the pain showed increased signal intensity within the ADQ muscle on T1 and T2 images indicating fatty infiltration. Short tau inversion recovery (STIR) images showed hyperintensity of the ADQ indicating oedema. The MRI scan of a 45-year old man who presented with a three month history of left heel pain revealed similar findings. These MRI appearances indicate subacute denervation, which, when involving solely the ADQ muscle suggests entrapment of the first branch of the lateral plantar nerve. Consideration of this imaging finding when examining MRI scans of patients with non-specific heel pain has the potential to facilitate diagnosis.
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Enfermedades del Pie/diagnóstico , Pie/inervación , Músculo Esquelético/inervación , Adulto , Femenino , Talón , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Músculo Esquelético/patología , Dolor/etiologíaRESUMEN
Sacral insufficiency fractures can be managed conservatively, by surgical fixation or by sacroplasty. This systematic review compared the outcomes of different treatment modalities to ascertain the best. Studies included in this systematic review were those with sacral insufficiency fracture in elderly patients with some measure of outcomes reported. Fractures due to high-energy trauma or malignancy or in non-elderly patients were excluded. The review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE and Embase databases were searched from inception to January 6, 2022, yielding a total of 4299 papers of which 35 were eligible for inclusion. Pain reduction following sacroplasty (Visual Analogue Scale (VAS) difference 5.83, SD 1.14, n = 901) was superior compared with conservative management (VAS difference 3.7, SD 2.71, n = 65) (p <0.0001) and surgical fixation (with screws/rods +/- cement augmentation; VAS difference 4.1, SD 1.106, n = 154) (p< 0.001). There was no significant difference between pain relief following screw fixation and after conservative management (p = 0.1216). Hospital stay duration was shorter following sacroplasty (4.1 days )SD 3.9)) versus fixation (10.3 days (SD 5.59)) (p= 0.0001). Available evidence points to sacroplasty resulting in better pain relief and shorter hospital stay than other treatment options.
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BACKGROUND: Surgical management of periacetabular bone metastases is challenging. The Harrington Plus reconstruction is a modification of the original Harrington rod technique. An intrapelvic suprapectineal plate is used, with the aim of reconstructing a disrupted anterior column and reducing the risk of failure in cases where there is extensive medial bone loss. METHODS: A retrospective review of the 13 patients who have undergone the Harrington Plus procedure to date was performed. Mobility status, EQ5D and Oxford Hip scores were assessed. RESULTS: There was a significant improvement in mobility status, EQ5D and Oxford Hip Scores at 6 months postoperatively (p < 0.05). Two patients returned to theatre for debridement of infection. There were no postoperative dislocations, cup medialisation or cases of loosening of the prosthesis. No patient required revision arthroplasty surgery. CONCLUSION: The Harrington Plus procedure produces a reliable construct that allows patients with extensive periacetabular metastatic defects to fully weight-bear. Careful patient selection and multidisciplinary management is essential.
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Pelvic fractures are complex injuries with a range of different presentations depending on the mechanism of trauma. Due to the morbidity and mortality of pelvic fractures, patients require thorough investigation and timely management with multidisciplinary input. Various surgical and non-surgical techniques can be used to treat pelvic fractures, as well as any associated visceral injuries. Following repair, it is important to remain vigilant for postoperative complications such as infection, sexual and urinary dysfunction, chronic pain and adverse psychological health. This article summarises the relevant UK guidance and literature and presents them in a format that follows the patient's journey. In doing so, it highlights the key perioperative factors that need to be considered in cases of pelvic fracture.
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Fracturas Óseas , Huesos Pélvicos , Fracturas Óseas/cirugía , Humanos , Huesos Pélvicos/cirugía , Complicaciones Posoperatorias , Estudios RetrospectivosRESUMEN
Long-stemmed uncemented implants are commonly used during revision hip arthroplasty but may be difficult to re-revise. Impaction bone grafting allows for the use of a shorter cemented stem during revision hip arthroplasty and may restore bone stock in patients with substantial femoral defects. Femoral impaction bone grafting is particularly beneficial in younger patients, who are more likely to require additional revision procedures in the future. The surgical technique used at our institution includes improvements to previous methods including the use of modular tamps and nonirradiated, size-profiled bone graft.
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Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Cementos para Huesos , Trasplante Óseo , Humanos , Falla de Prótesis , ReoperaciónRESUMEN
BACKGROUND: Autologous chondrocyte implantation (ACI) is a NICE-approved technique to regenerate hyaline cartilage in chondral and osteochondral defects (OCDs). The drawbacks of ACI include that it requires a two-stage approach, involves a lengthy rehabilitation process and is expensive. Bone marrow harvest with mesenchymal stem cell transplantation using a single-stage procedure and an accelerated rehabilitation programme has been developed to overcome this. The aim of this paper is to describe the surgical technique for stem cell transplantation of the knee for OCDs with reference to case examples. METHODS: The surgical technique for stem cell transplantation of the knee for OCDs is described, with reference to three cases. Magnetic resonance imaging was performed at six months postoperatively. RESULTS: The surgical technique is described in this paper. The three patient cases described all improved clinically with reduced pain and improved function at a minimum of six months follow-up. CONCLUSIONS: Stem cell transplantation has the potential to produce favourable outcomes for patients with osteochondral defects of the knee. This single-stage approach and accelerated rehabilitation is associated with reduced financial costs. A long-term prospective study of this technique is currently underway at our institution and randomised controlled trials are planned to demonstrate the effectiveness over other techniques.
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Cartílago Articular/cirugía , Condrocitos/citología , Artropatías/cirugía , Articulación de la Rodilla/cirugía , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/citología , Procedimientos Ortopédicos/métodos , Adolescente , Adulto , Femenino , Humanos , Artropatías/diagnóstico , Articulación de la Rodilla/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Recolección de Tejidos y Órganos/métodos , Trasplante Autólogo , Adulto JovenRESUMEN
AIMS: The aims of this study were to compare clinically relevant measurements of hip dysplasia on radiographs taken in the supine and standing position, and to compare Hip2Norm software and Picture Archiving and Communication System (PACS)-derived digital radiological measurements. METHODS: Preoperative supine and standing radiographs of 36 consecutive patients (43 hips) who underwent periacetabular osteotomy surgery were retrospectively analyzed from a single-centre, two-surgeon cohort. Anterior coverage (AC), posterior coverage (PC), lateral centre-edge angle (LCEA), acetabular inclination (AI), sharp angle (SA), pelvic tilt (PT), retroversion index (RI), femoroepiphyseal acetabular roof (FEAR) index, femoroepiphyseal horizontal angle (FEHA), leg length discrepancy (LLD), and pelvic obliquity (PO) were analyzed using both Hip2Norm software and PACS-derived measurements where applicable. RESULTS: Analysis of supine and standing radiographs resulted in significant variation for measurements of PT (p < 0.001) and AC (p = 0.005). The variation in PT correlated with the variation in AC in a limited number of patients (R2 = 0.378; p = 0.012). CONCLUSION: The significant variation in PT and AC between supine and standing radiographs suggests that it may benefit surgeons to have both radiographs when planning surgical correction of hip dysplasia. We also recommend using PACS-derived measurements of AI and SA due to the poor interobserver error on Hip2Norm. Cite this article: Bone Joint J 2021;103-B(11):1662-1668.
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Luxación de la Cadera/diagnóstico por imagen , Posición de Pie , Posición Supina , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Estudios Retrospectivos , Adulto JovenRESUMEN
BACKGROUND: Magnetic Resonance Imaging (MRI) is generally only indicated in patients with plantar heel pain who have atypical symptoms or who do not improve with appropriate management. MATERIALS AND METHODS: This study retrospectively reviewed the MRI findings of 112 patients with heel pain divided into two groups consisting of 50 patients with persistent pain despite appropriate treatment and 62 patients with atypical heel pain. RESULTS: Of the 50 patients with persistent heel pain, 38 (76%) of MRIs confirmed the diagnosis of plantar fasciitis. Of the 62 patients who had presented with atypical symptoms or signs, 21 patients had presented with night pain and the remaining 41 had presented with acute pain, tenderness of the lateral or medial aspect of the heel, significant swelling, neurological features or pain posterior to the insertion of the plantar fascia. Patients with night pain were shown to have plantar fasciitis associated with calcaneal marrow edema in 15 (71.4%) cases (p < 0.05). One patient presenting with night pain was found to have a plantar arterio-venous malformation. Acute pain was associated with plantar fascia tears in 4 out of 9 (p < 0.05). CONCLUSION: MRI may provide reassurance in cases of persistent heel pain but rarely changes the management. In cases of atypical heel pain, MRI may demonstrate other pathology such as plantar fascia tearing, calcaneal edema or arteriovenous malformation.
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Calcáneo/fisiopatología , Fascitis Plantar/diagnóstico , Talón/fisiopatología , Imagen por Resonancia Magnética/métodos , Dolor/diagnóstico , Distribución de Chi-Cuadrado , Diagnóstico Diferencial , Edema/diagnóstico , Edema/fisiopatología , Fascitis Plantar/fisiopatología , Femenino , Humanos , Masculino , Dolor/fisiopatología , Dimensión del Dolor , Estudios RetrospectivosRESUMEN
Chondral and osteochondral defects in the knee are common and may lead to degenerative joint disease if treated inappropriately.Conventional treatments such as microfracture often result in fibrocartilage formation and are associated with inferior results. Additionally, microfracture is generally unsuitable for the treatment of defects larger than 2-4 cm2.The osteochondral autograft transfer system (OATS) has been shown to produce superior clinical outcomes to microfracture but is technically difficult and may be associated with donor-site morbidity. Osteochondral allograft use is limited by graft availability and failure of cartilage incorporation is an issue.Autologous chondrocyte implantation (ACI) has been shown to result in repair with hyaline-like cartilage but involves a two-stage procedure and is relatively expensive.Rehabilitation after ACI takes 12 months, which is inconvenient and not feasible for athletic patients.Newer methods to regenerate cartilage include autologous stem cell transplantation, which may be performed as a single-stage procedure, can have a shorter rehabilitation period and is less expensive than ACI. Longer-term studies of these methods are needed. Cite this article: EFORT Open Rev 2020;5:156-163. DOI: 10.1302/2058-5241.5.190031.
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The success of osseointegrated transcutaneous prostheses depends on a soft-tissue seal forming at the skin-implant interface in order to prevent infection. Current designs include a flange with drilled holes or a subdermal barrier with a porous coating in an attempt to promote soft-tissue attachment. However, the soft-tissue seal is not reliably achieved despite these designs and infection remains a significant problem. This study investigated soft-tissue integration into fully porous titanium alloy structures with interconnected pores. The study aimed to determine the effect of altering pore and strut size combinations on soft-tissue ingrowth into porous titanium alloy structures in vivo. It was hypothesized that implants with a more open porous structure with larger pore sizes would increase soft-tissue ingrowth more than less open porous structures. Porous titanium alloy cylinders were inserted into sheep paparaspinal muscles (n = 6) and left in situ for four weeks. A histological assessment of soft-tissue ingrowth was performed. Percentage soft-tissue pore fill, cell nuclei density and blood vessel density were quantified. The results showed that larger pore sizes were supportive of soft-tissue ingrowth. A structure with a pore size of 700µm and a strut size of 300µm supported revascularisation to the greatest degree. A flange with this structure may be used in future studies of osseointegrated transcutaneous prostheses in order to enhance the soft-tissue seal.
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Oseointegración/efectos de los fármacos , Diseño de Prótesis/métodos , Titanio/farmacología , Aleaciones/química , Animales , Miembros Artificiales , Femenino , Implantes Experimentales , Ensayo de Materiales/métodos , Porosidad , Ovinos , Propiedades de Superficie , Titanio/químicaRESUMEN
A variety of options exist to reconstruct limbs following traumatic bone loss. The management of these injuries is challenging and often requires prolonged and potentially painful treatment. The Ilizarov technique of bone transport using circular external fixators is widely used for limb reconstruction of large bone defects. Other techniques include vascularised fibular grafting, the use of induced pseudosynovial membranes combined with cancellous autologous bone grafts and the use of autologous, allogeneic or synthetic bone grafts on their own for smaller defects. Future directions include further research on bone tissue engineering using stem cell therapy and growth factors such as bone morphogenetic proteins. The purpose of this Continuing Medical Education article is to describe the key limb reconstructive techniques that may be employed to treat traumatic bone loss. In particular, this article is intended to serve as a revision tool for those preparing for postgraduate examinations.
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Trasplante Óseo , Educación de Postgrado en Medicina , Peroné/trasplante , Técnica de Ilizarov , Recuperación del Miembro , Procedimientos de Cirugía Plástica , Trasplante de Células Madre/métodos , Prótesis Vascular , Proteínas Morfogenéticas Óseas/uso terapéutico , Trasplante Óseo/métodos , Fijadores Externos , Humanos , Técnica de Ilizarov/tendencias , Recuperación del Miembro/métodos , Procedimientos de Cirugía Plástica/métodosRESUMEN
The success of transcutaneous implants depends on the achievement of a soft tissue seal by enabling fibroblasts to win the race for the surface against bacteria. Fibronectin-functionalized hydroxyapatite coatings (HAFn) have been shown to improve dermal tissue ingrowth and attachment. However, during the early postoperative period before a soft tissue seal has formed, bacterial colonization may occur. This study explored the incorporation of silver, a broad spectrum antimicrobial agent, into HAFn coatings with the aim of reducing bacterial colonization. Silver is known to have dose-dependent cytotoxic effects. Therefore, the effects of silver incorporation into HAFn coatings on both in vitro human dermal fibroblast viability and Staphylococcus aureus colonization were assessed. An electrochemical deposition technique was used to codeposit hydroxyapatite and silver (HAAg) and fibronectin was adsorbed onto this to produce HAAgFn coatings. Surfaces were preconditioned with serum to mimic the in vivo environment. Nonpreconditioned HAAg and HAAgFn coatings suppressed bacterial colonization but were cytotoxic. After serum-preconditioning, more than 90% of fibroblasts that grew on all HAAg and HAAgFn coatings were viable. The highest silver content coatings tested (HAAg100 and HAAgFn100) resulted in a greater than 99% reduction in biofilm and planktonic bacterial numbers compared to HA and HAFn controls. Although HAAg100 had greater antibacterial activity than HAAgFn100, the findings of this study indicate that fibroblasts would win the race for the surface against S aureus on both HAAg100 and HAAgFn100 after serum-preconditioning.
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Antiinfecciosos/farmacología , Materiales Biocompatibles Revestidos , Fibroblastos/fisiología , Fibronectinas/farmacología , Infecciones Relacionadas con Prótesis/prevención & control , Plata/farmacología , Staphylococcus aureus/crecimiento & desarrollo , Animales , Carga Bacteriana , Supervivencia Celular , Durapatita/farmacología , Humanos , Prótesis e Implantes/efectos adversos , Staphylococcus aureus/efectos de los fármacosRESUMEN
Knee injuries involving ligament, articular cartilage and meniscus are common. The capacity for regeneration and repair of these tissues is limited due to their poor vascularity. Autologous or allogeneic stem cell transplantation has the potential to stimulate healing of these tissues. A number of preclinical studies of stem cell therapy for repair of these injuries have produced promising results. Further clinical trials are needed to test the efficacy of this technique. This paper reviews the development strategies, advances and clinical applications of stem cell therapies that are applicable to knee ligament, articular cartilage and meniscal injuries.
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Cartílago Articular/cirugía , Traumatismos de la Rodilla/terapia , Ligamentos/cirugía , Meniscos Tibiales/cirugía , Medicina Regenerativa/métodos , Trasplante de Células Madre , Células Madre/fisiología , Animales , Cartílago Articular/lesiones , Humanos , Ligamentos/lesiones , Medicina Regenerativa/tendencias , Lesiones de Menisco Tibial , Cicatrización de HeridasRESUMEN
Spinal pathologies are a major burden on society and individuals. Recent years have seen a large number of studies dedicated to the use of stem cells in spinal surgery. This review focuses on recent advances and controversies regarding the applications of stem cells in spinal fusion surgery, spinal cord injury and intervertebral disc degeneration. There are significant concerns regarding the ethics and risks of stem cell use. Animal models do not always accurately depict the human condition. While a great deal has been achieved, successful translation into clinical practice is needed. However there is no doubt that stem cells have a major role to play in the future management of spinal conditions.
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Degeneración del Disco Intervertebral/terapia , Traumatismos de la Médula Espinal/terapia , Trasplante de Células Madre , Células Madre/fisiología , Animales , Modelos Animales de Enfermedad , Humanos , Osteogénesis , Procedimientos de Cirugía Plástica , Medición de RiesgoRESUMEN
Physeal injuries may lead to the formation of a bone bridge resulting in limb length discrepancies and angular deformity in children. Current treatment of physeal injuries may be challenging. A number of strategies have been used to repair physeal defects with varying results. Biological regeneration using stem cells is therefore an attractive potential future option to repair physeal defects. Preclinical animal studies using stem cells have shown mixed results. Studies have investigated the use of various scaffolds including chitin, collagen and gelfoam. Significant progress has been made in discovering appropriate growth factors such as transforming growth factor (TGF-ß), insulin-like growth factor (IGF-1), bone morphogenetic proteins (BMPs) and fibroblast growth factor (FGF-2) that could induce physeal repair and be used in combination with stem cell therapy. Advances have been made in the use of gene therapy to maintain sustainable delivery of growth factors to injury sites. This review discusses the current stem cell therapy available to repair physeal injuries.
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Enfermedades del Desarrollo Óseo/terapia , Regeneración Ósea , Placa de Crecimiento/metabolismo , Trasplante de Células Madre , Heridas y Lesiones/terapia , Animales , Enfermedades del Desarrollo Óseo/etiología , Regeneración Ósea/genética , Niño , Terapia Genética , Placa de Crecimiento/patología , Humanos , Péptidos y Proteínas de Señalización Intercelular/genética , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Fracturas de Salter-Harris , Andamios del Tejido/estadística & datos numéricos , Cicatrización de Heridas/genética , Heridas y Lesiones/complicacionesRESUMEN
Joint diseases are a major cause of disability and are a significant financial burden on health care systems. Regenerative medicine offers exciting possibilities for treating osteoarthritis and rheumatoid arthritis. As well as possessing the ability to differentiate into other tissue lineages, some stem cells such as mesenchymal stem cells possess immmunomodulatory properties that make them useful in the search for alternative treatments for rheumatoid arthritis specifically. Various studies have been carried out using animal models to evaluate the role of stem cells in the treatment of arthritis, with some research being translated into clinical studies. However, the number of patients used in some studies has left questions on the ability of stem cell therapy to treat arthritic conditions unanswered. This article reviews the innovative studies that have been carried out to treat arthritis using stem cells and also highlights the key challenges associated with these techniques.
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Artritis Reumatoide/terapia , Regeneración Tisular Dirigida/métodos , Células Madre Mesenquimatosas/fisiología , Osteoartritis/terapia , Trasplante de Células Madre , Animales , Regeneración Tisular Dirigida/tendencias , Humanos , Modelos AnimalesRESUMEN
End-to-end suture of nerves and autologous nerve grafts are the 'gold standard' for repair and reconstruction of peripheral nerves. However, techniques such as sutureless nerve repair with tissue glues, end-to-side nerve repair and allografts exist as alternatives. Biological and synthetic nerve conduits have had some success in early clinical studies on reconstruction of nerve defects in the hand. The effectiveness of nerve regeneration could potentially be increased by using these nerve conduits as scaffolds for delivery of Schwann cells, stem cells, neurotrophic and neurotropic factors or extracellular matrix proteins. There has been extensive in vitro and in vivo research conducted on these techniques. The clinical applicability and efficacy of these techniques needs to be investigated fully.
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Tissue engineering of bone has the potential to overcome the limitations of using autologous, allogeneic or synthetic bone grafts to treat extensive bone defects. It involves culturing of osteogenic cells within appropriate scaffold materials under conditions that optimize bone development. Stem cells, progenitor cells, terminally differentiated cells or genetically modified cells may be used. Scaffold materials include polymers, ceramics or composites which are used to maintain the desirable characteristics of the individual materials. Preclinical and clinical studies on the use of growth factors such as bone morphogenetic proteins to increase bone formation have had promising results. This review discusses the approaches to and the challenges associated with producing tissue engineered bone.