Introduction. The purpose of this study was to analyse the efficacy and complications associated with the use of Calcium Sulphate synthetic bone graft in a paediatric population. There are no published articles on the use in children. Materials & Methods. A retrospective review was undertaken of the notes, microbiology, and X-Rays of 17 cases (in 15 patients) of calcium sulphate use in paediatric patients. As well as patient demographic data, data collected included indication, use of additional agents (antibiotics), return to theatre, and wound complications. Major complications were also assessed for. Results. There were 17 cases, in 15 patients, in our case series where calcium sulphate synthetic bone graft was used. The average patient age was 12.0 years (range 5 years – 17 years). Indications for use included likely infection (12), possible infection (3), and 2 elective finger cases (enchondroma and osteotomy). The humerus was the most common target site (5), followed by the femur (4), tibia (3), calcaneum (2), finger (2) and metatarsal (1) also included. There were positive intra-operative microbiology samples for eleven cases (Staphylococcus aureus and Staphylococcus epidermidis). Antibiotics were used in all cases except the elective finger surgery, and choice ranged between vancomycin, gentamicin, or a combination of both. Two patients required return to theatre for management of ongoing deep infection, although one case was later deemed to be non-infective osteomyelitis. Seven patients had undergone debridements prior to the definitive one with calcium sulphate (5 without Calcium Sulphate, 2 with Calcium Sulphate). Three patients experienced wound issues in the form of discharge/leakage, all were managed with dressings and did not require return to theatre. Conclusions. Calcium Sulphate synthetic bone graft, with addition of antibiotics, is an efficacious treatment in the paediatric population and is not associated with any major complications. Wound discharge should be observed for, and patients/parents warned about this, but only as per the adult population

Objective. To determine differences in fracture stability and functional outcome between synthetic bone graft and allograft/autograft with internal fixation of tibia plateau metaphyseal defects. Patient & Methods. Between 2007- 2008, 84 consecutive cases of internal fixation of tibia plateaux were identified from our theater logbook. 29 patients required additional autologous, allogenic bone graft, or synthetic bone graft substitute to ensure fracture stability. 5 patients were excluded due to lost to follow up leaving a cohort of 24 patients. Hydroxyapatite calcium carbonate synthetic bone graft was utilised in 14 patients (6 male and 8 female). Allograft/autograft were utilised in the remaining 10 patients (6 male and 4 female). All 24 patients had closed fractures, classified using the AO and Schatzker classification. Roentograms at presentation, post-operatively and regular follow-up till 12 months were analysed for maintenance of reduction, early and late subsidence of the articular surface. Functional outcomes such as knee range of movement and WOMAC Knee scores were compared between groups. Results. There was no significant statistical difference between groups for post-operative joint reduction, long term subsidence, and WOMAC scores. The degree of subsidence was not related to age or fracture severity. Maintenance of knee flexion was found to be better in the allograft/autograft group (p=0.015) when compared between groups. Multivariate analysis compared graft type, fracture severity, postoperative reduction, subsidence rate, range of movement and WOMAC score. The only finding was a statistical significant (p=0.025) association with the graft type and range of movement. Conclusion. Allograft/autograft may allow better recovery of long-term flexion, possibly due to reduced inflammatory response compared with synthetic bone graft. However, all other parameters such as maintenance of joint reduction and subjective outcome measures were comparable with the use of hydroxyapatite calcium carbonate bone graft. This study shows that synthetic bone graft is a suitable option in fixation of unstable tibia plateau fractures, avoiding risk of viral disease transmission with allograft and donor site morbidity associated with autograft

Aim. This study describes and correlates the radiographic and histologic changes which develop in a Gentamicin-eluting synthetic bone graft substitute. *. in the management of bone defects after resection of chronic osteomyelitis (COM). Method. 100 patients with COM were treated with a single stage procedure, including management of the dead space with insertion of a Gentamicin-eluting synthetic bone graft substitute. *. Radiographs of 73 patients with a follow-up of at least 12 months (range 12–33 months) were available for review. Bone defects were diaphyseal in 32, metaphyseal in 34 and combined in 7 patients. In 3 patients, radiographs were not of sufficient quality to allow analysis. Five patients had subsequent surgery, not related to recurrence of infection, which allowed biopsy of the implanted material. These biopsies were harvested between 12 days and 9 months after implantation. Tissue was fixed in formalin and stained with haematoxylin-eosin and immunohistochemically for bone matrix markers. Results. Radiographic: 31 of 34 diaphyseal implantations (91%) demonstrated remodelling of the biocomposite, gradually over many months, producing new bone and resulting in a “normal post-osteomyelitic” appearance. In metaphyseal implantations, new bone filled two-thirds or more of the defect in 55% of cases, one to two-thirds was filled in 31% and one third or less was filled in 14%. 22% of patients exhibited radiographic signs of dissolution and remodelling which are specific to this material. The ‘Halo’ sign of peripheral zone remodelling, the ‘Marble’ sign of dissolution and the ‘Puddle’ sign of distal migration can be described. Histologic: Histological assessment revealed early active remodelling of the biocomposite. The material was osteoconductive with accumulation of osteoblasts and osteoid and woven bone formation on the surface of the Gentamicin-eluting synthetic bone graft substitute. *. separated by fibrous tissue at the edge of the defect beneath reactive viable host bone. Fibrous tissue contained a heavy macrophage infiltrate and the newly formed matrix contained the specific bone proteins, dentine matrix protein-1 and podoplanin. There was limited evidence of remodelling into lamellar bone at 20 weeks after implantation. Conclusions. The Gentamicin-eluting synthetic bone graft substitute. *. exhibits a specific pattern of radiographic change over many months after implantation. The resolution of the bone defect would appear to be due to bone formation, as seen in the histologic and immunohistochemical analysis

Aim. Aim of this monocentric, prospective study was to evaluate the safety, efficacy, clinical and radiographical results at 24-month follow-up (N = 6 patients) undergoing hip revision surgery with severe acetabular bone defects (Paprosky 2C-3A-3B) using a combination of a novel phase-pure betatricalciumphosphate - collagen 3D matrix with allograft bone chips. Method. Prospective follow-up of 6 consecutive patients, who underwent revision surgery of the acetabular component in presence of massive bone defects between April 2018 and July 2019. Indications for revision included mechanical loosening in 4 cases and history of hip infection in 2 cases. Acetabular deficiencies were evaluated radiographically and CT and classified according to the Paprosky classification. Initial diagnosis of the patients included osteoarthritis (N = 4), a traumatic fracture and a congenital hip dislocation. 5 patients underwent first revision surgery, 1 patient underwent a second revision surgery. Results. All patients were followed-up radiographically with a mean of 25,8 months. No complications were observed direct postoperatively. HHS improved significantly from 23.9 preoperatively to 81.5 at the last follow-up. 5 patients achieved a defined good result, and one patient achieved a fair result. No periprosthetic joint infection, no dislocations, no deep vein thrombosis, no vessel damage, and no complaint about limbs length discrepancy could be observed. Postoperative dysmetria was found to be + 0.2cm (0cm/+1.0cm) compared to the preoperative dysmetria of − 2.4 cm (+0.3cm/−5.7cm). Conclusions. Although used in severe acetabular bone defects, the novel phase-pure betatricalciumphosphate - collagen 3D matrixshowed complete resorption and replacement by newly formed bone, leading to a full implant integration at 24 months follow-up and thus represents a promising method with excellent bone regeneration capacities for complex cases, where synthetic bone grafting material is used in addition to autografts

Introduction. Various biomaterials and bone graft substitute technologies for use in osteomyelitis treatment are currently used in clinal practice. They vary in mode of action (with or without antibiotics) and clinical application (one-stage or two-stage surgery). This systematic review aims to compare the clinical evidence of different synthetic antimicrobial bone graft substitutes and antibiotic-loaded carriers in eradicating infection and clinical outcome in patients with chronic osteomyelitis. Methods. Systematic review according to PRISMA statement on publications 2002-2023. MESH terms: osteomyelitis and bone substitutes. FREE terms: chronic osteomyelitis, bone infection. A standardized data extraction form was be used to extract data from the included papers. Results. Publications with increased methodological quality and clinical evidence for biomaterials in osteomyelitis treatment were published in the last decades. High 85-95% eradication rates of osteomyelitis were observed for various resorbable Ca-P and/or Ca-S biomaterials combined with antibiotics and S53P4 bioactive glass. Level of evidence varies significantly between products. Antibiotic pharmacokinetic release profiles vary between resorbable Ca-P and/or Ca-S biomaterials. Conclusion. Given the high 85-95% eradication rates of osteomyelitis by various resorbable Ca-P and/or Ca-S biomaterials combined with antibiotics and S53P4 bioactive glass, one-stage treatment is preferred. Surgeons should be aware of variations in mechanical properties and antibiotic pharmacokinetic release profiles between Ca-P and CA-s products. Mechanical, biological and antimicrobial properties of bioactive glass are formulation dependent. Currently, only S53P4 bioactive glass has proven antimicrobial properties. Based on this systematic review antibiotic loaded fleeces should be used with caution and restraint

Introduction. Core decompression is used in precollapse lesions to forestall disease progression in avascular necrosis (AVN) of femoral head (FH). The author reports a new technique using reverse bone graft technique to effectuate core decompression. Aim. To prevent precollapse in Ficat Type 1&2 and revascularization using synthetic bone graft material. Methods. A 18 year female police trainee with Magnetic Resonance Imaging (MRI) confirming AVN Stage 2 Ficat, clinically painful hip not evident in x-rays consented to undergo this new technique. Reverse bone graft technique with a Coring reamer – Patent 5423823. A minimally invasive technique with lateral 2 cm incision introducing 8.5 mm core reamer to remove a core of bone up to the subchondral bone. The subchondral cyst decompressed and curetted under video recorded Image Intensifier (II). Demarcated avascular bone segment excised and bone graft reversed and inserted with cortical bone acting as a support to prevent collapse and the distal segment augmented using 5 grams of osteoconductive granular synthetic bone graft material based on calcium phosphate hydroxyapatite (HA 2500–5000 μm). Avascular segment histopathologically confirmed AVN. The metaphyseal entry was extrapoliated at the lateral cortex using the combined necrotic angle described by Kerboul in the anteroposterior and lateral views under II. Protected weight bearing for 2 months to prevent stress riser. Biomaterials. HA granules named as GranuMas™ developed under Intensified Research in Priority Areas (IRPA) Research Project (No. 03-01-03-0000-PR0026/05) and invented by the Advance Materials Research Centre (AMREC) and manufactured by GranuLab –Patent P1 20040748 fulfilling the criteria for American Society for Testing and Materials (ASTM) F1185-88(1993) Standards which is ‘Standard Specification for Composition of Ceramic Hydroxyapatite for Surgical Implants’. Derived from Malaysian limestone, ranging from 200–5000 μm gamma sterilized. Results. After 6 months, there was no collapse of subchondral bone and the FH showed revascularization along bone grafted site with viable graft and increased radiotracer activity using 99-Tc MDP Bone Planar Scintigraphy. Clinical analysis follow up at 2 years was descriptive rather than statistical with a x-ray evident incorporated graft and with pain free full range of movement. Discussion. Reduction in intraosseous pressure is achieved by using large bore 8.5 mm coupled with HA granules promoting revascularization. The core tract entering through the metaphyseal region reduces risk of subtrochanteric fracture a potential complication of vascularized fibular grafts and with less morbidity with other treatment methods for osteonecrosis of the femoral head. The concept can be extended in introducing stem cell and biologic material to treat AVN. Conclusion. This technique is minimally invasive and effective in young patients with early stage of FH AVN and has shown revascularization along the bone grafted site

Aim. This study describes the histologic changes seen with a gentamicin-eluting synthetic bone graft substitute (BGS)(1) in managing bone defects after resection of chronic osteomyelitis (cOM). Method. 154 patients with mean follow-up of 21.8 months (12–56) underwent treatment of cOM with an antibiotic-loaded BGS for defect filling. Nine patients had subsequent surgery, not related to infection recurrence, allowing biopsy of the implanted material. These biopsies were harvested between 19 days and two years after implantation, allowing a description of the material's remodelling over time. Samples were fixed in formalin and stained with haematoxylin-eosin. Immunohistochemistry, using an indirect immunoperoxidase technique, identified the osteocyte markers Dentine Matrix Protein-1 (DMP-1) and Podoplanin, the macrophage/osteoclast marker CD68, and the macrophage marker CD14. Results. The material was actively remodelled and was osteoconductive. There was evidence of osteoblast recruitment, leading to osteoid and intramembranous formation of woven and lamellar bone on the material's surface, seen most prominently in areas of well-vascularised fibrous tissue. Osteocytes in woven bone expressed the markers DMP-1 and Podoplanin. No cartilage or endochondral ossification was seen. There was a prominent (CD14+/ CD68+) macrophage response to the BSG and macrophages within reparative cellular and collagenous fibrous tissue. In biopsies taken between 4 and 5 months, there were bone trabeculae containing BGS of mainly woven but partly lamellar type. Giant cells on the surface of newly formed mineralised osteoid and woven bone expressed an osteoclast phenotype (CD68+/CD14-). In later biopsies (up to 2 years), larger bone trabeculae were seen more frequently within well-vascularised reparative fibrous tissue. The BGS was replaced with predominantly lamellar bone. One biopsy was taken from an extraosseous leak of BGS into the soft tissues, behind the distal tibia. The histology showed a heavy macrophage infiltrate, but notably no evidence of osteoid or bone formation in the material or surrounding soft tissues. Conclusion. There was clear evidence that this BGS is osteoconductive with first osteoid then woven and lamellar bone being formed. DMP-1 and podoplanin-expressing osteocytes present in woven and lamellar bone demonstrate osteoclastic bone remodelling. Increased lamellar bone was noted in later samples and bone formation was most prominent in well-vascularised areas. There was on-going remodelling of the material beyond one year. The BGS did not ossify in soft tissue. The hydroxyapatite scaffold in this material is probably responsible for its high osteoconductivity and potential to be transformed into bone

To report our experience with the use of local antibiotic co-delivery with a synthetic bone graft substitute during a second stage re-implantation of an infected proximal humeral replacement. A 72 year old man was admitted to our department with a pathological fracture through an osteolytic lesion in the left proximal humerus, due to IgG Myelomatosis. He was initially treated with a cemented proximal humerus replacement hemiarthroplasty. Peri-prosthetic joint infection (PJI) with significant joint distention was evident three weeks post operatively. Revision surgery confirmed presence of a large collection of pus and revealed disruption of the soft tissue reattachment tube, as well as complete retraction of rotator cuff and residual capsule. All modular components were removed and an antibiotic-laden cement spacer (1.8g of Clindamycin and Gentamycin, respectively) was implanted onto the well-fixed cemented humeral stem. Initial treatment with i.v. Amoxicillin/Clavulanic acid was changed to Rifampicin and Fusidic Acid during a further 8 weeks after cultures revealed growth of S. epidermidis. During second stage revision, a hybrid inverse prosthesis with silver coating was implanted, with a total of 20 ml Cerament ™G (injected into the glenoid cavity prior to insertion of the base plate and around the humeral implant-bone interface) and again stabilized with a Trevira tube. Unfortunately, this prosthesis remained unstable, ultimately requiring re-revision to a completely new constrained reverse prosthesis with a custom glenoid shell and silver-coated proximal humeral component. 18 months postoperatively, the patient's shoulder remains pain free and stable, without signs of persistent or reinfection since the initial second stage revision. The function however, unfortunately remains poor. This case report illustrates the application of an antibiotic-eluting bone graft substitute in a specific clinical situation, where co-delivery of an antibiotic together with a bone remodeling agent may be beneficial to simultaneously address PJI as well as poor residual bone quality

Aim. The demand for a synthetic bone substitute that can build bone and at the same time kill bacteria is high. The aim of this study was to compare the elution of gentamicin from a new synthetic bone substitute in vitro with the performance in clinical applications. Method. Gentamicin release was measured from a synthetic bone graft substitute, comparing in vitro and clinical conditions:. 1). elution in Ringers solution. The bone graft substitute contained 175mg gentamicin per 10mL. The material was introduced either as paste or as pre-set beads with a high or low surface areas, >100cm. 2. and 24cm. 2. respectively. The gentamycin release was measured by daily collection of samples. 2). elution in patients treated for trochanteric hip fractures(n=6) or uncemented hip revisions(n=5) 7,3±1,1mL of substitute was implanted and drainage was collected at 6h,12h,24h,30h,36h post-op. Blood serum was collected every hour for the first 6h and thereafter every 6h until 4 days post-op, urine – daily for the first 7 days post-op. 3). elution in patients treated after bone tumor resection(n=8), 12,1±5,5mL of substitute was implanted and both drainage and blood serum were collected daily until 2 days post-op. Gentamicin concentrations were analyzed using antibody technique. Results. In the in vitro study, there was an initial peak in the gentamicin concentration (GC) for all the samples and at a level above 4mg/L, which is the MIC break point, during the whole test period of 28 days. All gentamicin was released during the test period and more than 95 % had been released after 2–4 days independently of the surface area of the material, or if it was pre-set or paste. In the clinical studies similar results were found. Gentamicin was detected in the drainage until 2 days post-op. and the hip patients 40% less GC – compared to the tumor patients. In the blood serum with higher GC in the tumor patients and non-detectable levels after 2 days post-op for the hip patients. The GC was significantly lower than maximum systemic level recommended of 12 mg/L. In the urine, GC was above the MIC of 4mg/L for the first seven days post-op. Conclusions. A reliable in vitro test method has been identified for the future development of additional new and effective antibiotic containing bone substitutes. The new bone regenerating carrier gives very high local antibiotic release for a controlled short time after surgery and high systemic serum concentrations are avoided

The ITS volar radial plate (Implant Technology Systems, Graz/Austria) is a fixation device that allows for the distal locking screws to be fixed at variable angles (70°-110°). This occurs by the different material properties, with the screws (titanium alloy) cutting a thread through the plate holes (titanium). We present our experience with the ITS plate. We retrospectively studied 26 patients who underwent ITS plate fixation for unstable multifragmentary distal radial fractures (AO types A3, B2, B3, C2, C3). The surgery was performed either by a consultant orthopaedic hand surgeon or senior registrar. A volar approach was used every time and 10 cases required synthetic bone grafting. Post-operatively they were immobilised for an average of 2.5 weeks. The 26 patients had a mean age of 58 and the dominant side was affected in 46% of cases. 5 cases were open fractures and 10 cases followed failed manipulation under general anaesthesia. The average interval between injury and surgery was 7 days. Union was achieved in all cases. No implant infections, failure or tendon rupture/irritation occurred. There were two fractures which loss reduction, of which one required revision surgery. There was one case of CRPS. The six month average DASH score was 27.5. We consider the ITS plate a technically easy plate to use and a reliable implant at early follow-up. We value the versatility of its variable angle screw fixation ability for complex intra-articular distal radial fractures