Background. Plate fixation is one of several options available to surgeons for the management of pediatric femur fractures. Recent literature reports distal femoral valgus can be a complication following lateral plate fixation of femur fractures. We report on a case of extreme distal femoral valgus deformity and a lateral dislocation of the patella four years after having plate fixation of a left distal femoral fracture. Method. A single case was anonymised and retrospectively reviewed through examination of clinical and radiographic data. Results. A 15 year old male presented with 35 degree femoral valgus deformity, one inch leg length discrepancy, painful retained hardware and a lateral dislocation of the patella four years after undergoing lateral plate fixation of a left distal femur fracture. The fracture site healed after plate insertion, but later the patient reported worsening in alignment of lower extremity and complained of pain in the limb. Antero-posterior and lateral radiographs of the femur revealed 35 degrees of left distal femoral valgus. The previous femoral plate migrated proximally and was encased in bone. Due to plate migration, screws that were originally in the distal femoral metaphysis were protruding through the femoral shaft into soft tissues of the medial thigh. Successful treatment involved removal of prominent distal screws and use of a Taylor Spatial external fixator frame to correct the deformity. Lateral soft tissue release was performed to allow patellar relocation. At 12 weeks follow up leg alignment was restored, pain resolved and the patient was mobilising. Conclusion. Femoral valgus is a possible complication of lateral plate fixation in up to 30% of pediatric distal femur fractures. With this patient's combination of deformities as an example, we suggest early hardware removal after fracture union, preventing deformities developing. If plate removal is not chosen, then continued close monitoring of the patient is necessary until skeletal maturity. Level of Evidence. Type 4 (case report)

Fractures repair by two mechanisms; direct fracture healing and indirect fracture healing via callus formation. Research concerning the effects of bisphosphonate on fracture repair has solely assessed indirect fracture healing. Patients with osteoporosis on bisphosphonates continue to sustain fragility fractures. A proportion of osteoporotic fractures require plate fixation. Bisphosphonates impair osteoclast activity and therefore, may adversely affect direct fracture healing that predominates with plate fixation. Five skeletally mature Sprague-Dawley rats received daily subcutaneous injections of 1mg/kg Ibandronate (IBAN). Similarly, five control rats received saline (CONTROL). Three weeks following commencement of injections a tibial osteotomy was rigidly fixed with compression plating similar to that seen in routine clinical practice. Fracture healing was monitored with radiographs. Six weeks post plate fixation, animals were sacrificed. Radiographs were performed of the extricated tibiae following plate removal. The visibility of the osteotomy site was scored as totally visible, partially visible or absent as previously described. Mechanical testing was conducted on the healing osteotomies via 4-point bending. Fractures healed without visible external callus. In the IBAN group three animals had totally visible osteotomy lines and two had partially visible osteotomy lines. The CONTROL group had three animals with absent osteotomy lines and two with partially visible osteotomy lines. The mean (±SD) stress at failure for the healing tibial osteotomies at 6 weeks was 28.8 (±23.97)MPa in the IBAN group and 37.4(±29.20) MPa in the CONTROL group (p=0.62). Our results indicate that Ibandronate adversely affected direct fracture repair as demonstrated by the radiographic density of the fracture line. The strength of the repair was reduced but this did not reach statistical significance. Our results suggest that a sample size of 220 animals is required to detect a 15% difference (alpha 0.05, beta 0.2) which suggests the effect of bisphosphonates on direct fracture repair may be small

Background. Surgical management of calcaneus fractures is demanding and has a high risk of wound complications. Traditionally these fractures are managed with splinting until swelling has subsided. We describe a novel protocol for the management of displaced intra-articular calcaneus fractures utilising a temporizing external fixator and staged conversion to plate fixation through a sinus tarsi approach. The goal of this technique is to allow for earlier treatment with open reduction and internal fixation, minimise the amount of manipulation required at the time of definitive fixation and reduce the wound complication rate seen with the extensile approach. Methods. The records of patients with displaced calcaneus fractures from 2010–2014 were retrospectively reviewed. A total of 10 patients with 12 calcaneus fractures were treated with this protocol. All patients underwent ankle-spanning medial external fixation within 48 hours of injury. Patients underwent conversion to open plate fixation through a sinus tarsi approach when skin turgor had returned to normal. Time to surgery, infection rate, wound complications, radiographic alignment, and time to radiographic union were recorded. Results. The average Bohler's angle improved from 13.2 (range −2 to 34) degrees preoperatively to 34.3 (range 26 to 42) degrees postoperatively. The average time from external fixation to conversion to internal fixation was 4.8 (range 3 to 7) days. There were no immediate post-surgical complications. The average time to weight bearing was 8.5 weeks. The average time to radiographic union was 9.5 (range 8 to 12) weeks. There were no infections or wound complications at the time of last follow-up. Conclusions. Early temporizing external fixation for the acute management of displaced calcaneus fractures is a safe and effective method to reduce and stabilise the foot and may decrease the time to definitive fixation. In our series there were no complications related to the use of the external fixator. Level of Evidence. IV Retrospective case series

Clavicular hook plates have been used over the last decade in the treatment of lateral clavicular fractures with good rates of union reported throughout the literature. Fewer studies have reported the functional outcome of these patients and some have reported potential soft tissue damage post plate removal. We aimed to review the functional outcomes alongside union rates in patients treated with hook plates for lateral clavicular fractures.

In this retrospective case series, 21 patients with traumatic lateral third clavicular fractures were included. 15 had Neer type II fractures, 4 Neer type III fractures, 1 patient had a Neer type I fracture and 1 radiograph was not able to be classified. All patients were treated with clavicular hook plates at the same district general hospital by five experienced surgeons between March 2010 and February 2015 adhering to the same surgical protocol. All patients had standard physiotherapy and post operative follow up. Plates were removed when radiological union was achieved in all but one patient who had the plate removed before union was achieved due to prolonged non-union. Patients were followed up post plate removal and evaluated clinically using the Oxford Shoulder Score. Their post plate radiographs were assessed by an independent radiologist and bony union documented.

21 patients were included. Mean age was 40 (range 14–63) with a male:female ratio of 17:4. Mean follow up was 5 months post injury (1–26 months). The hook plate remained in situ for a mean time of 4.3 months (2–16 months). One patient developed a post-operative wound infection treated with antibiotics, 2 patients developed adhesive capsulitis, one patient had not achieved bony union prior to hook plate removal at 16 months, however did achieve union 2 months post plate removal, two patients required revision plating. All patients achieved bony union eventually with good alignment and no displacement of the acromioclavicular joint seen on the most recent post operative radiographs. Post plate removal Oxford Shoulder Scores indicated good shoulder function with a mean score of 41.5 (maximum score possible 48 and the range of scores for our cohort was 30–47).

Our data would support the use of hook plates in the treatment of lateral clavicular fractures. All patients achieved union eventually with good alignment and this was reflected in the good functional outcome scores. This study is limited in its small cohort and short-term follow up. More research is required to examine the long term consequences of hook plate surgery in a larger patient population.

Abstract. Objectives. There is debate regarding the optimal surgical technique for fixing femoral diaphyseal fractures in children aged 4 to 12 years. The aim of this study was to conduct a systematic review and meta-analysis to compare the complication rate following flexible intramedullary nailing (FIN), plate fixation and external fixation (EF) for traumatic femoral diaphyseal fractures in children aged 4 to 12. Methods. We searched MEDLINE, EMBASE and CENTRAL databases for interventional and observational studies. Two independent reviewers screened, assessed quality and extracted data from the identified studies. The primary outcome was the risk of any complication. Results. Nine randomised controlled trials (RCTs) and 19 observational studies fulfilled the eligibility criteria. Within the RCTs, five analysed FIN (n=161), two analysed plates (n=51) and five analysed EF (n=168). Within the observational studies, 13 analysed FIN (n=610), seven analysed plates (n=214) and six analysed EF (n=153). The overall risk of complications was lower following plate fixation when compared to FIN (RR 0.45, 95% CI 0.28 to 0.73, p=0.001) in the observational studies. The overall risk of complications was higher following EF when compared to FIN in both RCTs (RR 1.94, 95% CI 1.25 to 3.01, p=0.003) and observational studies (RR 1.97, 95% CI 1.50 to 2.58, p<0.001). The overall risk of complications was higher following EF when compared to plate fixation in both RCTs (RR 7.42, 95% CI 1.84 to 29.98, p=0.005) and observational studies (RR 4.39, 95% CI 2.64 to 7.30, p<0.001). Conclusions. This study reports a significantly decreased relative risk of complications when femoral diaphyseal fractures in children aged 4 to 12 are managed with plates. The overall quality of evidence is low, highlighting the need for a prospective multicentre randomised trial at low risk of bias due to randomisation and outcome measurement to identify if any fixation technique is superior

Introduction and Objective. The most common paediatric orthopaedic injury requiring hospital admission is a femoral fracture. There is debate regarding the optimal surgical technique for fixing femoral diaphyseal fractures in children aged 4 to 12 years. The National Institute for Health and Care Excellence (NICE) and the American Academy of Orthopaedic Surgeons (AAOS) have issued relevant guidelines, however, there is limited evidence to support these. The aim of this study was to conduct a systematic review and meta-analysis to compare the complication rate following flexible intramedullary nailing (FIN), plate fixation and external fixation (EF) for traumatic femoral diaphyseal fractures in children aged 4 to 12. Materials and Methods. We searched MEDLINE, EMBASE and CENTRAL databases for interventional and observational studies. Two independent reviewers screened, assessed quality and extracted data from the identified studies. The primary outcome was the risk of any complication. Secondary outcomes assessed the risk of pre-specified individual complications. Results. Nine randomised controlled trials (RCTs) and 19 observational studies (six prospective and 13 retrospective) fulfilled the eligibility criteria. Within the RCTs, five analysed FIN (n=161), two analysed plates (n=51) and five analysed EF (n=168). Within the observational studies, 13 analysed FIN (n=610), seven analysed plates (n=214) and six analysed EF (n=153). The overall risk of complications was lower following plate fixation when compared to FIN fixation (RR 0.45, 95% CI 0.28 to 0.73, p=0.001) in the observational studies. The overall risk of complications was higher following EF when compared to FIN fixation in both RCTs (RR 1.94, 95% CI 1.25 to 3.01, p=0.003) and observational studies (RR 1.97, 95% CI 1.50 to 2.58, p<0.001). The overall risk of complications was higher following EF when compared to plate fixation in both RCTs (RR 7.42, 95% CI 1.84 to 29.98, p=0.005) and observational studies (RR 4.39, 95% CI 2.64 to 7.30, p<0.001). Conclusions. Although NICE and the AAOS recommend FIN for femoral diaphyseal fractures in children aged 4 to 12, this study reports a significantly decreased relative risk of complications when these injuries are managed with plates. Our findings provide valuable information to healthcare professionals who are involved in discussing the risk and benefits of different management options with patients and their families. The overall quality of evidence is low, highlighting the need for a rigorous prospective multicentre randomised trial at low risk of bias due to randomisation and outcome measurement to identify if any fixation technique is superior

Osteosynthesis of high-energy metaphyseal proximal tibia fractures is still challenging, especially in patients with severe soft tissue injuries and/or short stature. Although the use of external fixators is the traditional treatment of choice for open comminuted fractures, patients' acceptance is low due to the high profile and therefore the physical burden of the devices. Recently, clinical case reports have shown that supercutaneous locked plating used as definite external fixation could be an efficient alternative. Therefore, the aim of this study was to evaluate the effect of implant configuration on stability and interfragmentary motions of unstable proximal tibia fractures fixed by means of externalized locked plating. Based on a right tibia CT scan of a 48 years-old male donor, a finite element model of an unstable proximal tibia fracture was developed to compare the stability of one internal and two different externalized plate fixations. A 2-cm osteotomy gap, located 5 cm distally to the articular surface and replicating an AO/OTA 41-C2.2 fracture, was virtually fixed with a medial stainless steel LISS-DF plate. Three implant configurations (IC) with different plate elevations were modelled and virtually tested biomechanically: IC-1 with 2-mm elevation (internal locked plate fixation), IC-2 with 22-mm elevation (externalized locked plate fixation with thin soft tissue simulation) and IC-3 with 32-mm elevation (externalized locked plate fixation with thick soft tissue simulation). Axial loads of 25 kg (partial weightbearing) and 80 kg (full weightbearing) were applied to the proximal tibia end and distributed at a ratio of 80%/20% on the medial/lateral condyles. A hinge joint was simulated at the distal end of the tibia. Parameters of interest were construct stiffness, as well as interfragmentary motion and longitudinal strain at the most lateral aspect of the fracture. Construct stiffness was 655 N/mm (IC-1), 197 N/mm (IC-2) and 128 N/mm (IC-3). Interfragmentary motions under partial weightbearing were 0.31 mm (IC-1), 1.09 mm (IC-2) and 1.74 mm (IC-3), whereas under full weightbearing they were 0.97 mm (IC-1), 3.50 mm (IC-2) and 5.56 mm (IC-3). The corresponding longitudinal strains at the fracture site under partial weightbearing were 1.55% (IC-1), 5.45% (IC-2) and 8.70% (IC-3). From virtual biomechanics point of view, externalized locked plating of unstable proximal tibia fractures with simulated thin and thick soft tissue environment seems to ensure favorable conditions for callus formation with longitudinal strains at the fracture site not exceeding 10%, thus providing appropriate relative stability for secondary bone healing under partial weightbearing during the early postoperative phase

Background. Currently about 4–6% of all femur fractures consist of distal femoral fractures. Different methods and implants have been used for the surgical treatment of distal femoral fractures, including intramedullary nails. Retrograde nail. By contrast with antegrade nails, surgical approach or retrograde nailing exposes the knee joint which may lead to tendency of infection and increased knee pain. Present study aims to compare the biomechanical behaviour of distal angular condyler femoral intramedullary nail (DACFIN), retrograde nail and plate fixation. Methods. Fifteen 4th generation Saw bones were used to evaluate the biomechanical differences between the groups (Group 1: Plate fixation, Group 2: Retrograde nailing, Group 3: DACFIN; (n=5)). Biomechanical test was performed by using an electromechanical test device Shimadzu (AG-IS 5kN, Japan). Displacement values were recorded by using a Non-contact Video Extensometer (DVE-101/201, Shimadzu, Japan) during the loading each femur with 5 cycles of 500 N at a rate of 10 N/s to determine axial stiffness. The faliure stiffness was measured by axial load to each constructat a displacement rate of 5 mm/min. Torsional loading applied to all groups in amount of 6 Nm of torque with a velocity of 18 degrees/min. Results. The mean torsion stiffness value of Group 3 (6.33 Nm/degree) was signifacantly higher than Group 1 (1.18 Nm/degree) and Group 2 (2.11Nm/degree), p<0.05). The failure stiffness, Group 3 (1725 N/mm) was significantly higher than Group 1 (1275 N/ mm) and Group 2 (1290 N/mm). However, In axial stiffness, the mean value of Group 2 (2554 N/mm) was higher than Group 3 (1822 N/mm), and signifantly higher than Group 1(468 N/mm), p<0.05). Conclusions. DACFIN is more stiffer than retrograde nail and plate fixation during torsional and failure load conditions. But in axial stiffness retrograde nail was stiffer. DACFIN provide intramedullary femur condyle fracture fixations without open knee joint. Level of evidence. Level 5. Disclosure. Authors declare that there is no conflict of interest related to the present study

Abstract. Objectives. Operative management of distal humerus fractures is challenging. In the past, plates were manually contoured intraoperatively, however this was associated with high rates of fixation failure, nonunion and metalwork removal. Anatomically pre-contoured distal humerus locking plates have since been developed. Owing to the rarity of distal humeral fractures, literature regarding outcomes of anatomically pre-contoured locking plates is lacking and patient numbers are often small. The purpose of this study is to investigate the outcomes of these patients. Methods. We retrospectively identified patients with distal humeral fractures treated at our institution from 2009–2018. Inclusion criteria were patients with a distal humeral fracture, who underwent two-column plate fixation with anatomically pre-contoured locking plates. Clinical records and radiographs were reviewed to elicit outcome measures, including range of motion, complications and reoperation rate. Results. We identified 50 patients with mean age of 55 years (range 17–96 years). Mean length of follow up was 5.2 years. AO fracture classification Type A occurred most frequently (46%), followed by Type B (22%) and Type C (32%). Low energy mechanisms of injury predominated in 72% of patients. Mean time from injury to fixation was seven days. Mean range of motion at the elbow was 13–123o postoperatively. The overall reoperation rate was 22%, the majority of which required subsequent removal of prominent metalwork (18%). The incidence of nonunion, heterotopic ossification, deep infection and neuropathy requiring decompression was 2% each. Fixation failure occurred in only one patient however the fracture went on to heal. Conclusions. Previously reported reoperation rates with manually contoured plates were as high as 44%, which is twice our reported rate. Modern locking plates are no longer subject to implant failure (previously 27% reported metalwork failure rate). Likewise, heterotopic ossification and non-union have also reduced, highlighting that modern plates have significantly improved overall patient outcomes. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction:. Mayo 2A Olecranon fractures are traditionally managed with a tension band wire device (TBW) but locking plates may also be used to treat these injuries. Objectives:. To compare clinical outcomes and treatment cost between TBW and locking plate fixation in Mayo 2A fractures. Methods:. All olecranon fractures admitted 2008–2013 were identified (n=129). Patient notes and radiographs were studied. Outcomes were recorded with the QuickDASH (Disabilies of Arm, Shoulder and Hand) score. Incidence of infection, hardware irritation, non-union, fixation failure and re-operation rate were recorded. Results:. 89 patients had Mayo 2A fractures (69%). Of these patients 64 underwent TBW (n=48) or locking plate fixation (n=16). The mean age for both groups were 57 (15–93) and 60 (22–80) respectively. In the TBW group, the final follow-up QuickDASH was 12.9, compared with 15.0 for the Locking plate group. There was no statistically significant difference between either group (p = 0.312). 19 of the 48 TBW patients had complications (48%). There was 1 infection (2%). 15 cases of metalwork irritation (31%). 1 non-union (2%). 2 fixation failures (4%). 14 of the 48 TBW patients had re-operations (29%). There were 13 removal of metalwork procedures (27%), 1 washout (2%) and 2 revision fixations (4%). There were 0 complications and 0 re-operations in the 16 patients who underwent locking plate fixation. This was statistically significant, (p = 0.003) and (p= 0.015) respectively. TBW costs £7.00 verses £244.10 for a locking plate. Theatre costs were equivalent. A 30 minute day surgery removal of metalwork or similar case costs £1420. In this cohort, when costs of re-operation were included, locking plates were on average £177 less per patient. Conclusions:. Locking plates are superior to TBW in terms of incidence of post-operative morbidity and re-operation rate. Financial savings may be made by choosing a more expensive initial implant

Locking plates have led to important changes in bone fracture management, allowing flexible biological fracture fixation based on the principle of an internal fixator. The technique of locking plate fixation differs fundamentally from conventional plating and has its indications and limitations. Most of the typical locking plate failure patterns are related to basic technical errors, such as under-sizing of the implant, too short working length, and imperfect application of locking screws. After analysis of the fracture morphology and intrinsic stability following fracture reduction, a meticulous preoperative planning is mandatory under consideration of the principles of the internal fixator technique to avoid technical errors and inaccuracies leading to early implant failure

Locking plate fixation in proximal humeral fractures has demonstrated good results tempered by a significant rate of loss of fixation. Reported rates of failure are typically around 10% of cases but can be 20% or higher. In addition large series are often made up of a diverse patient population, so we have chosen to focus solely on patients confirmed to have significantly reduced BMD who can be considered a subset at high risk of fixation failure. Twenty-three patients (5 male, 18 female) with a proximal humeral fracture treated by locking plate fixation were confirmed on DEXA scanning to be osteopaenic (17), osteoporotic (4) or severely osteoporotic (2). Patients early in the series were reviewed retrospectively and recalled for an updated assessment where appropriate, and the remainder were followed prospectively. The average age was 66 years (range 49 to 82). Follow up was for an average of nine months following surgery (range 2 and a half to 28 months). 17 patients underwent surgery for acute injuries and 6 for established surgical neck non-unions. Seven injuries were 2-part fractures, 12 3-part, 3 were 4-part and one a 2-part surgical neck non-union.1 plate failed due to complete loss of fixation within 2 months in a patient with severe osteoporosis and was treated with removal of metalwork. This was the only injury that failed to unite. Avascular necrosis occurred in three patients with two revised to a hemiarthroplasty. 1 patient had ongoing pain and underwent removal of the plate. Our series demonstrated that locking plate fixation of proximal humeral fractures is associated with a low rate of fixation failure and satisfactory outcomes in patients with significantly reduced bone mineral density

Background. Patients suffering a distal femoral fracture are at a high risk of morbidity and mortality. Currently this cohort is not afforded the same resources as those with hip fractures. This study aims to compare their mortality rates and assess whether surgical intervention improves either outcome or mortality following distal femoral fractures. Methods. Patients over sixty-five admitted with a distal femoral fracture between June 2007 and 2012 were retrospectively identified. Patients mobility was categorised as unaided, walking aid, zimmer frame, or immobile. The 30-day, six-month, and one-year mortality rates were recorded for this group as well as for hip fractures during the same period. Results. 68 patients were included in the study. 85% of the patients were female and the mean age was 84 years. 8 patients (12%) had an underlying total knee arthroplasty. 43 patients (63%) were managed non-operatively and of those treated surgically 7 had plate fixation (28%) and 18 had intramedullary nailing (72%). The mortality rate for all patients with distal femoral fractures was 7% at 30 days, 26% at six months, and 38% at one year, higher than hip fractures during the same period by 8%, 13%, and 18%, respectively. Patients managed surgically had lower mortality rates and higher mobility levels. Conclusion. Patients suffering a distal femoral fracture have a high mortality rate and surgical intervention seems to improve both mobility and mortality. Currently this group of patients obtains less attention and resources than hip fracture patients. Further research assessing the impact of increasing resources on this group of patient is required. Level of evidence. IV. Conflict of Interests. The authors confirm that they have no relevant financial disclosures or conflicts of interest. Ethical approval was not sought as this was a systematic review

Bone tissue engineering constructs (BTEC) combining natural resorbable osteoconductive scaffolds and mesenchymal stem cells (MSCs) have given promising results to repair critical size bone defect. Yet, results remain inconsistent. Adjonction of an osteoinductive factor to these BTEC, such as rh-BMP-2, to improve bone healing, seems to be a relevant strategy. However, currently supraphysiological dose of this protein are used and can lead to adverse effects such as inflammation, ectopic bone and/or bone cyst formation. Interestingly, in a preliminary study conducted in ectopic site in a murine model, a synergistic effect on bone formation was observed only when a low dose of rh-BMP-2 was associated with MSCs-seeded coral scaffolds but not with a high dose. The objective of the study was then to evaluate a BTEC combining coral scaffold, MSCs and a low dose of rh-BMP-2 in a large animal model of clinical relevance. Sixteen sheep were used for this study. MSCs were isolated from an aspirate of bone marrow harvested from the iliac crest of each sheep receiving BTEC with MSCs, cultivated and seeded on Acroporacoral scaffolds one week before implantation. Rh-BMP-2, used at two different doses (low dose: 68μg/defect and high dose: 680μg/defect), was diluted and absorbed on Acroporacoral scaffold one day before implantation. Metatarsal segmental bone defects (25 mm) were made in the left metatarsal bone of the sheep, stabilized by plate fixation, and filled with Acroporacoral scaffolds loaded with either (i) MSCs and a low dose of rh-BMP-2 (Group 1;n=6), (ii) a low dose of rh-BMP-2 (Group 2;n=5), (iii) a high dose of rh-BMP-2 (Group 3;n=5). Standard radiographs were taken after each surgery and each month until sheep sacrifice, 4 months postoperatively. Bone healing and scaffold resorption were assessed by micro-computed-tomography (μCT) and histomorphometry. Results were compared to a historical control group in which coral scaffolds were loaded with MSCs. Bone volumes (BV) evaluated by μCT and bone surfaces (BS) evaluated by histomorphometry did not differ between groups (BV: 1914±870, 1737±841, 1894±1028 and 1835±1342 mm. 3. ; BS: 25,41±14,25, 19,85±8,31, 25,54±16,98 and 26,08±22,52 %; groups 1, 2, 3 and control respectively); however, an higher bone union was observed in group 1 compared to the others (3, 1, 2 and 2 sheep with bone union in groups 1, 2, 3 and control respectively). No histological abnormalities were observed in any group. Coral resorption was almost complete in all specimens. No significant difference in coral volumes and coral surfaces was observed between groups. A trend towards a higher variability in coral resorption was noted in group 1 compared to the others. There seems to be a benefit to associate low dose of rh-BMP-2 with MSCs-seeded coral scaffolds as this strategy allowed an increase of bone unions in our model. Yet, results remain inconsistent. Although, defective coupling between scaffold resorption and bone formation impaired bone healing in some animals, adjunction of rh-BMP-2 (even at low dose) to CSMs loaded construct is a promising strategy for bone tissue engineering

Summary Statement. Tibia plateau split fracture fixation with two cancellous screws is particularly suitable for non-osteoporotic bone, whereas four cortical lag screws provide a comparable compression in both non-osteoporotic and osteoporotic bone. Angle-stable locking plates maintain the preliminary compression applied by a reduction clamp. Introduction. Interfragmentary compression in tibia plateau split fracture fixation is necessary to maintain anatomical reduction and avoid post-traumatic widening of the plateau. However, its amount depends on the applied fixation technique. The aim of the current study was to quantify the interfragmentary compression generated by a reduction clamp with subsequent angle-stable locking plate fixation in an osteoporotic and non-osteoporotic synthetic human bone model in comparison to cancellous or cortical lag screw fixation. Methods. Adult synthetic human tibiae with hard or soft cancellous bone were osteotomised at the lateral tibia plateau creating a split fracture (AO type 41-B1) and fixed with either two 6.5 mm cancellous, four 3.5 mm cortical lag screws or 3.5 mm LCP proximal lateral tibia plate, preliminary compressed by a reduction clamp (n = 5 per group). Interfragmentary compression was measured by a pressure sensor film after instrumentation. One-way analysis of variance (ANOVA) with Bonferroni post hoc correction was performed for statistical analysis (p < 0.05). Results. Applying a reduction clamp, interfragmentary compression was 0.6 MPa ± 0.1 in non-osteoporotic and osteoporotic bone. The locking plate was able to maintain the compression (0.5 MPa ± 0.1) in non-osteoporotic and osteoporotic bone, but it was significantly lower compared to four cortical lag screws (non-osteoporotic p = 0.01; osteoporotic p = 0.03). Comparing four 3.5 mm cortical lag screws, compression was not significantly different between the non-osteoporotic (1.7 MPa ± 0.7) and osteoporotic bone (1.4 MPa ± 0.5). Two 6.5 mm cancellous lag screws achieved significantly higher compression in non-osteoporotic (2.1 MPa ± 0.6) compared to osteoporotic (0.8 MPa ± 0.2, p = 0.01) bone. Conclusion. Preliminary compression applied by a reduction clamp was maintained by angle-stable locking plates. The two 6.5 mm cancellous screw technique would especially be appropriate for young human non-osteoporotic bone, whereas the four 3.5 mm cortical screw configuration could also be applied in osteoporotic bone

The effect of bisphosphonates on the mechanical properties of the uninjured contra-lateral cortical bone during fracture healing is poorly reported. There remains conflicting evidence with regards the effect of bisphosphonate therapy on cortical bone strength. We assessed the effect of nine weeks of Ibandronate therapy, in a dose known to preserve cancellous bone BMD and strength, on the mechanical properties of the uninjured rat tibial diaphyses using a standardised model of tibial osteotomy and plate fixation. Skeletally mature ex-breeder rats were used. Stress at failure of the tibial diaphyses was measured by a four-point bending test using a custom made jig for rat tibiae. The mechanical strength was compared with radiographic measurements of bone density. Animals received daily subcutaneous injections. 11 rats received 1μg/kg Ibandronate (IBAN) daily and 17 rats received 1ml 0.9% Sodium Chloride (CONTROL) daily. The IBAN group had a statistically significant, p=0.024, higher stress at failure 212.7 (±42.04) MPa compared to the CONTROL group 171.7 (±46.13)MPa. There was a positive correlation between the mechanical strength of bone and the radiological measure of bone density. Osteopenia is known to occur following a fracture even in the contra-lateral limb. This study demonstrates that ibandronate therapy has no detrimental effect and may even increase the strength of uninjured cortical bone during the fracture healing process. The longer term effect of ibandronate on cortical bone especially in relation to the accumulation of mico-damage requires further study. Bisphosphonate effect on the uninjured limb needs to be considered when reporting proportional strength of fracture repair compared to the uninjured limb

Periprosthetic femoral fractures can occur as a complication of total hip arthroplasty and are often challenging to treat as the mechanical scenario is influenced by the presence of the metal prosthesis within the bone. This research focuses on finding the optimum fixation for transverse, Vancouver type B1 periprosthetic fractures, stabilised using locking plates and secured using screws. The aim of this study was to experimentally validate a computer model of a human femur, develop that model to represent a periprosthetic femoral fracture fixation and show how the model could be used to indicate differences between plating techniques. In the first development stage, both a laboratory model and a finite element model were developed to evaluate the mechanical behaviour of an intact composite femur under axial loading. Axial strains were recorded along the medial length of the femur in both cases and compared to provide validation for the computational model predications. The computational intact femur model was then modified to include a cemented total hip replacement, and further adapted to include a periprosthetic fracture stabilised using a locking plate, with unicortical screws above, and bicortical screws below the transverse fracture. For the intact femur case, the experimental and computational strain patterns correlated well with an average difference of 16%. Following the inclusion of the stem, there was a reduction in the strain in the region of the prosthesis reducing by an average of 45%. There was also a large increase in bulk stiffness with the introduction of the prosthesis. When the fracture and plate fixation were included, there was little difference in the proximal strain where the stem dominated, and the strains in the distal region were found to be highly sensitive to the distribution of the screws. The results of this study indicate that screw configuration is an important factor in periprosthetic fracture fixation. A laboratory model of the periprosthetic facture case is now under development to further validate the computational models and the two approaches will then be used to determine optimum fixation methods for a range of clinical scenarios

Background. Volar locking plates have revolutionised the treatment for distal radius fractures. The DVR (Depuy) plate was one of the earliest locking plates which were used and they provided fixed angle fixation. Recently, newer volar locking plates, such as the Aptus (Medartis), have been introduced to the market that allow the placement of independent distal subchondral variable-angle locking screws to better achieve targeted fracture fixation. The aim of our study was to compare the outcomes of DVR and Aptus volar locking plates in the treatment of distal radial fractures. Methods. Details of patients who had undergone open reduction and internal fixation of distal radii from October 2007 to September 2010 were retrieved from theatre records. 60 patients who had undergone stabilisation of distal radius fractures with either DVR (n=30) or Aptus (n=30) plate were included in the study. Results. Mean age of patients undergoing fixation using DVR plate was 56.6 years (n=30) with 22 females and 8 males. Fractures in this group included 20 type 23-C, three type 23-B and seven type 23-A. The patients were followed up for an average of 5.5 months (2-16 months). 3 patients underwent revision of fixation due to malunion (n=1), non-union (n=1) and failure of fixation (n=1). Four patients had reduced movements even after intensive physiotherapy necessitating removal of plate. Mean age of patients undergoing Aptus volar locking plate fixation was 56.38 years (n=30) with 21 females and 9 males. There were 27 type 23-C, two type 23-B and one type 23-A fractures according to AO classification. The patients were followed up for an average of 4.1 months (2-11 months). 2 patients developed complex regional pain syndrome (CRPS) and 1 patient underwent removal of screws due to late penetration of screws into the joint. Conclusion. Complex and unstable fractures of the distal radius can be optimally managed with volar locking plates. Both systems are user friendly. Aptus plates provide an additional advantage of flexibility in implant positioning and enhanced intra-fragmentary fixation compared to the DVR plate. In our study Aptus plates had lower secondary surgical procedures compared to DVR plates