Introduction: Osteochondral lesions of the talus (OCL III–IV°) need both extensive debridement for revitalisation and osteochondral reconstruction of the joint surface. This can be achieved by autologous cancellous bone-grafting and combination with a cell-free bioresorbable collagen-I/III scaffold. Our first results with this technique are presented. Methods: 25 patients (13 female, 12 male, mean age 30.9 years) with 26 osteochondral lesions of the talus (OCL III–IV°, 15 right, 11 left, 24 medial, 2 lateral, 1 bilateral case) were treated by minimal-invasive debridement, autologous cancellous bone-grafting and application of a porcine collagen-I/III scaffold (ChondroGide. ®. ) and evaluated prospectively by clinical scoring and MRI. The average follow-up was 23.2 (6–36) months. The mean defect size was 2.0 cm. 2. , the mean depth 0.7 cm. 14 defects have had at least one (1–3) operation on the defect before. By the use of a distractor a malleolar osteotomy could be avoided in all cases. Results: The AOFAS-score increased from 67.4 ± 12.2 to 89.5 ± 7.4 points (p< 0.01, t-test). On a visual 10-point scale pain decreased significantly from 6.2 to 1.7 while subjective ankle function improved from a mean of 4.4 ± 1.9 to 7.2 ±1.5. The results were rated excellent in 10/26 cases (38.4%), good in 14/26 (53.8) and fair in 2/26 (7.8%) cases. MRI follow-ups showed a complete or nearly complete defect filling. In two ankles a second-look arthroscopy unveiled the defects filled completely by a regenerative tissue with a smooth surface and good bonding. Full-core biopsies showed a mixed, mostly fibrocartilagenous tissue. Conclusion: By combination of cancellous bone-grafting with a cell-free collagen-I/III scaffold typical osteochondral lesions of the talus can be adressed effectively in a minimal-invasive one-step procedure. By utilizing mesenchymal stem cells (MSC) for an autogenous reparation process the use of expensive cultured chondrocytes is not necessary. The results concerning clinical functional improvement, pain reduction and patients’ satisfaction as well as defect filling in MRI are promising

In revision total hip arthroplasty (THA), it is essential to cope with the bone stock loss. The acetabular bone loss is reconstructed by bulk bone grafts, bone chips, bone cement or jumbo cup. The impaction bone-grafting (IBG) technique is a technique that can restore acetabular bone loss, while enough bone allografts are not easy to obtain and the quality is not always sufficient. Thus we mixed hydroxyapatite (HA) granules into bone chips to supplement the volume and the mechanical strength of allografts. To investigate the dynamic migration of cemented cup fixed with IBG, we made acetabular bone defect models and the migration of the cup was traced by a high-speed photography camera. Composite test blocks were used as synthetic acetabulum models. A hemisphere defect of 60mm in diameter was made. We tested 4 different bone/HA ratio; 100%/0%, 75%/25%, 50%/50% and 0%/100%. Each group consisted of 6 specimens. The grafted materials were impacted using impactors. Then, a 46 mm polyethylene cup was fixed with bone cement. The specimens were clamped to the MTS mechanical tester at an angle of 20 degrees. A dynamic load of 150 N to 1500 N with a frequency of 1 Hz was applied for 15 minutes, followed by a dynamic load of 300 N to 3000 N for the same time period. Then the load was released for 15 minutes. The cup migration was traced by the camera during loading and releasing. This camera captures 15 images per second thus it enables us to trace the migration of the cup during cyclic loading. The cup migration at the end of 3000N loading was measured. Elastic recoil was defined as the difference between the migration at the end of 3000N loading and that when the load reached to 0N. Visco-elastic recoil was defined as the difference between the migration at the release of loading and that after 15 minutes. Data were investigated by Pearson’s correlation coefficient test. A strong negative correlation (r = −0.71) was observed significantly between the amount of the migration and bone/HA ratio. In elastic recoil, statistically significant correlation was (r = −0.55) observed. In visco-elastic recoil, there is no correlation between the amounts of the visco-elastic recoil and bone/HA ratio. In the reconstruction of bone defects, initial stability of the cup is a first step to expect the long term survival. The initial stability depends on the mechanical properties of the grafted materials. To supplement the volume and mechanical strength of bone allografts, we added HA granules to the bone chips. In the current study, the cup migration was smaller by adding HA granules. Elastic recoil was affected, while visco-elastic recoil was not affected. These results indicated that the mixture of HA granules to bone chips stabilized the cup during loading period and load releasing period

We treated 19 patients with established nonunion of the radius and/or ulna by the excision of avascular bone and the grafting of blocks of corticocancellous bone from the iliac crest, augmented by rigid plate fixation under compression. This allowed early mobilisation, and bony union was achieved between three and 24 months after operation in all but one of the patients. The single failure was attributed to the excessive length of the defect (100 mm) and inadequate fixation.

Introduction: Revitalizing of the necrotic subchondral bone is the therapeutic paradigm in OCL/OD of the talus. Bone-marrow stimulation includes K-wire drilling or open debridement and cancellous bone grafting. Our results presented here are based on retrograde core-drilling and autologous cancellous bone-grafting of the talar dome guided by fluoroscopy and arthroscopy. Performed as a minimal-invasive technique, no additional harvesting site for bone-grafting is necessary. Methods: 38 patients (16 female, 25 male) with 41 symptomatic focal osteochondral lesions (ICRS I–III°) of the talus (3 bilateral) were treated by fluoroscopicguided retrograde coredrilling and autologous cancellous bone-grafting from the drilling cylinder. The results were evaluated retrospectively by use of the Ogilvie-Harris-Score (OHS), subjective clinical ratings on a visual analogue scale (VAS (0–10 max.)) and MRI. The patient’s mean age was 33.2 (±15.4) years. 27 patients (66%) reported a trauma history (sprain, compression). Most defects were located in the medial talus (36/41), 4 were lateral and 1 central. 34 cases were primary interventions. In 14 cases the growth plate of the distal tibial epiphysis was detectable. Results: The follow-up was 7–54 months with a mean of 29 (±13) months. The arthroscopic findings according to ICRS classified 12/41 as I°, 22/41 as II° and 7/41 as III° lesions. Preoperatively there were 11 poor, 25 fair, 4 good and 1 excellent ratings in the OHS-score turning into 1/9/13/18 postoperatively. There were 75.6% (31/41) overall good/excellent results. Good or excellent results were predominantly seen in grade I with 91.6% (11/12) and in grade II with 77.3% (17/22), whereas grade III showed success only in 42.8% (3/7). Open growth plates resulted good or excellent results in 85.7% (12/14 cases). First-line treatments showed a markedly better outcome of 82.3% (28/34) of good/ excellent results compared to 42.8% (3/7) of second-line treatments. Gender or trauma history did not influence the score results. Pain intensity on a VAS significantly reduced from 7.5 (±1.5) to 3.7 (±2.6). The subjective functional status on the VAS revealed a remarkable increase from 4.6 (±2.3) to 8.2 (±2.0), (p< 0.01). In MRI controls two patients showed a progression into demarcation (IV°) associated with a fair or poor score result. Conclusion: Our results indicate that fluoroscopic-guided retrograde core-drilling and autologous cancellous bone grafting is an appropriate operative option for talar OCL in minor grades I + II. Performed as a minimal-invasive technique, the subchondral necrosectomy and combined bone-grafting provide extended revitalization properties for OCL healing. Tending to success rates of only 42% in lesions III°, this technique can not generally be recommended here

Abstract. Background. Scaphoid non-union can result in pain, altered wrist kinematics leading to a Scaphoid Non-union Advance Collapse, ultimately to symptomatic radio-carpal arthritis. Open techniques have their limitations. We describe the rationale, surgical technique and outcomes of our series of arthroscopic bone-grafting (ABG) and fixation of scaphoid non-union. Methods. We performed a prospective single-surgeon series of 22 consecutive patients with clinico-radiologically established scaphoid non-union between March 2015 and April 2019. Data was collected from Electronic Patient Records, Patient Archived Computer system (PACS) and hand therapy assessments. We collected demographic data including age, hand-dominance, occupation and mechanism of injury. The Disabilities of the Arm, Shoulder and Hand Score (Quick DASH), Mayo wrist score, Patient Rated Wrist Evaluation (PRWE) and grip-strength measurements were collected preoperatively and at follow-up appointments. Results. There was an improvement in all outcome measures when comparing preoperative and postoperative results. The Quick DASH score improved by a mean of 24 points, Mayo wrist and PRWE scores improved by 15.1 and 29.7 points, respectively. Grip-strength analysis also improved by 6.1 kgf (Right) and 3.3kgf (Left). Follow-up computerised tomography scans revealed union in 18/22 patients with 2 patients lost to follow-up. One patient required revision ABG procedure to achieve union. Conclusion. Arthroscopic bone grafting and fixation of scaphoid non-union allows a minimally invasive method of managing these injuries. It has advantages of minimal morbidity and accurate articular reduction resulting in less postoperative stiffness and increased functional outcomes. It is an effective alternative to conventional open treatment of established scaphoid non-union

Severe glenoid bone loss in patients with osteoarthritis with intact rotator cuff is associated with posterior glenoid bone loss and posterior humeral subluxation. Management of severe glenoid bone loss during shoulder arthroplasty is controversial and technically challenging and options range from humeral hemiarthroplasty, anatomic shoulder replacement with glenoid bone grafting or augmented glenoid component implantation, to reverse replacement with reaming to correct version or structural bone grafting or metallic augmentation of the bone deficiency. Shoulder replacement with severe glenoid bone loss is technically challenging and characterised by higher rates of complications and revisions. Hemiarthroplasty has limited benefit for pain relief and function especially if eccentric glenoid wear exists. Bone loss with >15 degrees of retroversion likely requires version correction include bone-grafting, augmented glenoid components, or reverse total shoulder replacement. Asymmetric reaming may improve version but is limited to 15 degrees of version correction in order to preserve subchondral bone and glenoid bone vault depth. Bone-grafting of glenoid wear and defects has had mixed results with graft-related complications, periprosthetic radiolucent lines, and glenoid component failure of fixation. Implantation of an augmented wedge or step polyethylene glenoid component improves joint version while preserving subchondral bone, but is technically demanding and with minimal short term clinical follow-up. A Mayo study demonstrated roughly 50% of patients with posteriorly augmented polyethylene had radiolucent lines and 1/3 had posterior subluxation. Another wedge polyethylene design had 66% with bone ingrowth around polyethylene fins at 3 years. Long term outcomes are unknown for these new wedge augmented glenoid components. Reverse shoulder arthroplasty avoids many risks of anatomic replacement glenoid component fixation and stability but is associated with a high complication rate (15%) including neurologic and baseplate loosening and often requires structural bone grafting behind the baseplate with suboptimal outcomes or metallic augmented baseplates with limited evidence and short term outcomes. Reverse replacement with baseplate bone grafting or metal augmentation is technically challenging due to limited native glenoid bone stock available for baseplate component ingrowth and long term fixation. Failure to correct glenoid superior inclination and restore neutral version within 10 degrees increases the risks of reverse baseplate failure of fixation, pull out, and failure of reverse replacement. Reverse baseplate failure rates in patients with severe glenoid bone loss and concomitant glenoid bone grafting range from 5–11%. The minimum native glenoid bony contact with the baseplate is unknown but likely is approximately 1cm of native bone contacting a central ingrowth post and a minority (∼15–25%) of native glenoid contacting the backside of the baseplate. Failure to correct posterior bone loss can lead to retroversion of the baseplate, reduced external rotation, posterior scapular notching, and posteromedial polyethylene wear. In summary, shoulder replacement with severe glenoid bone loss is technically challenging and characterised by higher rates of complication and revision

Acetabular revision in patients with bone deficiency is often difficult because of the poor quality and quantity of the acetabular bone stock. The purpose of this study was to evaluate the midterm clinical and radiographic outcomes of acetabular revision with use of an impaction bone-grafting technique and a cemented polyethylene cup. Results: thirty consecutive acetabular revisions were performed with impaction bone-grafting and use of a cemented cup in twenty-eight patients with bone deficiency. The average age at the revision was sixty-eight years. The minimum duration of follow-up of all reconstructions that were still functioning or that were followed until the time of death was three years (mean, 8.1 years; range, three to fifteen years). The acetabular bone defects were classified as cavitary in fifteen hips and as combined segmental-cavitary in fifteen hips according to AAOS classification. One hip had a repeat revision. Radiographic analysis that had not been revised showed loosening in four hips. All these four hips were treated by bulk bone graft covering more than 50% of cups. Kaplan-Meier analysis demonstrated a prosthetic survival rate, with aseptic loosening as the end point, of 72% at fourteen years and, with revision as the endpoint, of 100% at ten years and 83% at fourteen years. Impaction bone-grafting was an excellent option to manage acetabular revision surgery. However, excessive bulk bonegraft should not be used

It is still unclear whether it is best, when revision surgery is required for replacement of an acetabular component, to treat femoral focal osteolysis with bone-grafting or instead to leave it untreated because the defect is too small and uncontained; the concern is to prevent bone graft from escaping into the hip joint. We hypothesized that progression of osteolysis can halted if the cause of particulate generation is removed and the femoral component is well osseointegrated. We prospectively followed 21 patients (24 hips) who underwent acetabular revision and curetting of proximal femoral osteolysis. These patients were followed for the minimum 3 years (mean, 4.3 years; range, 3–7.4 years). At the time of the latest follow-up examination, all hips were judged to be stable and to have well-fixed acetabular cups and femoral stems. No hips had significant progression of the osteolytic defect through the follow-up period and none demonstrated any new osteolytic lesion. Provided that a femoral component is bone ingrown with osseointegration sufficient to provide long-term stability, that the osteolytic defect is in the proximal aspect of the femur, and that the defect is uncontained, simple curettage is an effective alternative to additional bone-grafting

Aim. Post traumatic distal tibia osteomyelitis (DTOM) with an upper ankle joint involvement is a serious complication after primary osteosynthesis and can be a nightmare for the patient and the surgeon as well. Our aim was to identify mayor complications during treatment and to find the way to prevent or treat them. Method. It is a retrospective analysis of eight patients with DTOM and an upper ankle joint involvement treated in our institution from 2012 to 2018. The average size of a bone defect after a debridement was 9 centimeters (4–15). Patients were treated in two stages. First stage was segmental bone resection, external fixation and soft tissue envelope reconstruction if necessary. At second stage a distraction frame was applied and proximal corticotomy performed. In all but one case a circular frame was used. Results. We have had one major intra-operative complication, an injury of arteria tibialis posterior during the corticotomy procedure. Except in one patient we did not observe major problems with pin-track infections. Despite bone-grafting in all patients, we observed three nonunions of docking site. We treated them by external fixator in two and retrograde intramedullar nail in one case. In two patient the distraction callus was weak. We had to bone graft and secure the callus with a plate in one and use a retrograde reamed intramedullar nail in second patient. We have observed two callus fracture after removal of the frame. A surgery was needed for both because of the deformation. The first patient was treated by new external frame, the second by retrograde reamed intramedullar nail. Conclusions. Callus distraction is a valuable option to treat a bone defect. The procedure has many possible problems and complications, especially during treatment of defects larger than six centimeters. It is very difficult for patients to tolerate a frame more than one year. We have found the use of an intramedullar tibial nail inserted in a retrograde way as a helpful option not just to shorten the time of external frame, but in combination with reaming also to accelerate the healing of the distraction callus and the upper ankle joint arthrodesis as well

Osteonecrosis of the femoral head (ONFH) is a debilitating, painful, progressive, and refractory disease that has multiple etiologic risk factors. It is caused by bone cell death, which itself has various causes, leading to femoral head collapse and subsequent osteoarthritis. ONFH primarily influences patients aged from 20 to 50 years; in addition, bilateral hip joints are involved in 75% of patients. Causes include use of corticosteroids, alcohol abuse, previous trauma, hemoglobinopathy, Gaucher disease, coagulopathies, and other diseases. No pharmacologic treatment has been shown to be effective for early ONFH. Outcomes of total hip arthroplasty (THA) for these young and active patients have some drawbacks, primarily due to the young age of these patients, limited lifetime and durability of the implants and their fixation, and the skeletal manifestations of osteonecrosis. As a result of these concerns, there has been an increased focus on early interventions for ONFH aimed at preservation of the native articulation. Core decompression is currently the most widely accepted surgical treatment at the early stage of avascular osteonecrosis (AVN); however, due to limited efficacy, its use has been debated. There is currently no standardised protocol for evaluating and treating osteonecrosis of the femoral head in adults in the United States. Although total hip replacement is the most frequent intervention for treatment of post-collapse (Steinberg stage-IIIB, IVB, V, and VI) osteonecrosis; core decompression is the most commonly offered intervention for symptomatic, pre-collapse (Steinberg stage-IB and IIB) osteonecrosis. Less frequently offered treatments include non-operative, pharmacologic or modality management, osteotomy, vascularised and non-vascularised bone-grafting, hemiarthroplasty, resurfacing and arthrodesis. A promising, minimally invasive, core decompression procedure combined with a mesenchymal stem cell grafting technique which restores vascularity and heals osteonecrotic lesions has become popularised. This procedure is called a bone marrow aspirate concentrate (BMAC) procedure. During a BMAC, mesenchymal stem cells (in the form of concentrated iliac crest bone marrow) are injected through a core decompression tract into the area of necrosis in the femoral head. Most patients with early (pre-collapse) disease have excellent results at 2 to 5 years of clinical follow-up. Patients are weight bearing as tolerated on crutches after the procedure for 6 weeks, and are able to go home on the same day or next day after surgery with minimal pain. We can report on the early, promising results of 300 patients with ONFH treated with BMAC in the United States by two expert hip surgeons with at least 75%-80% survivorship. The care of adults with osteonecrosis of the femoral head is highly variable. This paper will discuss the various non-operative and operative treatment algorithms for ONFH available today. We will also report on a promising, new technique (BMAC), which improves the efficacy of traditional core decompression for early ONFH. The goal of treatment of early ONFH is to avoid THA in young, active patients and this talk will discuss those interventions and treatments which help accomplish that goal

Massive bone loss on both the femur and tibia during revision total knee arthroplasty (TKA) remains a challenging problem. Multiple solutions have been proposed for small osseous defects, including morselised cancellous bone grafting, small-fragment structural allograft, thicker polyethylene inserts, and the use of modular augments attached to revision prosthetic designs. Large osseous defects can be treated with structural allografts, impaction bone-grafting with or without mesh augmentation, custom prosthetic components, and specialised hinged knee components. The metaphyseal area of the distal femur and proximal tibia is a particularly attractive option during revision TKA given that it is usually undamaged and well-vascularised. While multiple reconstructive options have been recommended, porous tantalum metaphyseal cones have the advantage of improved biologic fixation because of their high porosity (75–80%), interconnected pore space, and low modulus of elasticity (3 MPa) similar to that of cancellous bone. Such features allow tantalum cones to fill bone defects while tolerating physiological loads. Indications for porous tantalum metaphyseal cones include patients with Anderson Orthopaedic Research Institute Type 2B or greater defects. The surgical technique is simpler than structural allograft reconstructions with decreased preparation time, resulting in a possible decrease in infection rates. The modularity of porous tantalum metaphyseal cones also allows the surgeon to choose a size and position that best fits the individual defect encountered. Moreover, tantalum cones can be used with several revision systems. Short-term clinical follow up indicates that porous tantalum metaphyseal cones effectively provide structural support with the potential for long-term biologic fixation and durable reconstructions

Introduction. The optimal management of severe tibial and/or femoral bone loss in a revision total knee arthroplasty (TKA) has not been established. Reconstructive methods include structural or bulk allografts, impaction bone-grafting with or without mesh augmentation, custum prosthetic components, modular metal augmentations of prosthesis and tumor prosthesis. Recently metaphyseal fixation using porous tantalum cones (Zimmer, Warsaw, IN) has been proposed as alternative strategy for severe bone loss. Objectives. The purposes of this study were to determine the clinical and radiographic outcomes in patients who underwent revision knee arthroplasty with tantalum cones with a minimum of 5-year follow-up. Methods. From November 2005 to August 2008 a total of 26 porous tantalum metaphyseal cones were used to reconstruct severe tibial and/or femoral bone loss in 18 patients during revision TKA at a single institution. There were 12 females and 6 males with an average age of 73 years (range 55–84) at the time of revision. The mean clinical and radiographic follow-up was 6.3 years (range, 5–8). The reasons for revision were aseptic loosening (5 cases) and deep infection (13 cases). A Two stage procedure was used in all septic cases. According to the Anderson Orthopaedic Reseach Institute (AORI) bone defects classification all femoral and tibial defects were rated 2B and 3 (3 T2b, 9 T3, 3 F2b and 10 F3). A femoral cone was inserted in 6 patients, a tibial cone was inserted in 5, a double cone in 6 (femoral and tibial), and a triple cone in 1 (1 femoral and 2 tibial). A constrained condylar implant (LCCK, Zimmer, Warsaw) was inserted in 6 patients and a rotating hinge knee implants (RHK, Zimmer, Warsaw, IN) in 12 pateints. All patients were prospectively followed for clinical and radiographic evaluation preoperatively and postoperatively at 1, 3, 6 months, one year and yearly thereafter. Results. Knee Society knee scores improved from a mean of 31.3 points before surgery to 76.7 points at latest followup (p < 0.001). Knee Society function scores improved from a mean of 21.7 points before surgery to 65.4 points at latest followup (p < 0.001). The average flexion contracture was 6° and the average flection was 88°. At the time of the latest follow-up the average flexion contraction was 3° and the average flexion was 105°. No radiolucent lines were seen between the cones and the adjacent tibial and femoral bone at the latest follow-up. There was no evidence of loosening or migration of any implant at the time of the final follow-up. There have been two reoperations for recurrent infection (11%). Conclusions. Our experience demonstrates excellent clinical and radiographic mid-term outcomes and confirms that metaphyseal fixation with porous tantalum cones can be achieved. Long-term follow up and comparative studies are necessary

We reviewed the results of the treatment of 30 tibial fractures with minor to severe bone loss in 29 patients by early soft-tissue and bony debridement followed by primary locked intramedullary nailing. Subsequent definitive closure was obtained within the first 48 hours usually with a soft-tissue flap, and followed by bone-grafting procedures which were delayed for six to eight weeks after the primary surgery. The time to fracture union and the eventual functional outcome were related to the severity and extent of bone loss. Twenty-nine fractures were soundly united at a mean of 53.4 weeks, with delayed amputation in only one patient. Poor functional outcome and the occurrence of complications were usually due to a departure from the standard protocol for primary management. We conclude that the protocol produces satisfactory results in the management of these difficult fractures, and that intramedullary nailing offers considerable practical advantages over other methods of primary bone stabilisation

Aims

The purpose of this study was to assess the success rate and functional outcomes of bone grafting for periprosthetic bone cysts following total ankle arthroplasty (TAA). Additionally, we evaluated the rate of graft incorporation and identified associated predisposing factors using CT scan.

Aims

The aim of this study was to assess the clinical and radiological results of patients who were revised using a custom-made triflange acetabular component (CTAC) for component loosening and pelvic discontinuity (PD) after previous total hip arthroplasty (THA).

Aims: In the present study we evaluated short-term outcome of complex proximal tibial fractures treated with hybrid external þxation. Methods: A retrospective evaluation of 33 tibiae in 31 patients treated with hybrid external þxation; 9 (27.2%) AO type A metaphyseal and 24 (72.8%) type C bicondylar intraarticular proximal tibial fractures. Majority of the fractures (58.1%) were due to high-energy trauma and open fractures constituted 18.2% of all fractures. Percutaneous pinning combined with indirect reduction techniques was used in 14 (42.4%) cases. Mini-open clamp reduction and screw þxation was applied in 12 (36.4%) operations. Open reduction, reconstruction of articular surface, bone-grafting and screw þxation combined with the hybrid frame was used in 7 (21.2%) patients. Results: Uneventful consolidation without complications occurred in 13 (39.4%) patients. The mean time to bony fusion was 18 ± 6.6 weeks. However, in 21.2% of the patients the fracture had not consolidated by 24 weeks. There were 5 (20.8%) primary re-operations due to malreduction of a type C fracture. In addition 3 (33.3%) type A metaphyseal fractures were re-operated upon due to non-union by 24 weeks. Two (6.1%) fractures united in axial malalignment and required an osteotomy. Conclusions: Our þndings suggest that due to high rate of unsatisfactory reductions, hybrid external þxation may not be the method-of-choice in þxation of displaced intra-articular proximal tibial fractures. It may be indicated in þxation of high energy metaphyseal fractures, but includes a signiþcant risk of delayed consolidation

Introduction There are 1 million cases of major skeletal defects :that occur worldwide each year that lead to significant morbidity and disability and currently require bone grafting as the main mode of treatment. Limitations of bone-grafting include donor site morbidity, reduced osseoinductivity and risk of pathogen transmission to the host. There is considerable interest in finding ways of differentiating mesenchymal stem cells down the osteoblastic lineage to form bone tissue. We hypothesized that there is an optimum strain that promotes differentiation of mesenchymal stem cells into osteoblasts. Methods: A bioreactor was developed that was capable of applying tensional forces across a culture strip in a graduated manner within a range of 1-4373me. Mesenchymal stem cells were grown on these strips and subjected to cyclical tensile strain at 1Hz. Cell morphology using Scanning Electron Microscopy, mineralization using specialized stains and expression of core binding factor1 (Cbfa1) was studied at various strain levels. Results: Scanning Electron Microscopy revealed classic osteoblastic cells in the regions subjected to tensile force, especially in the region where average strain was 1312me. X-ray microanalysis revealed calcium deposits on the strip, indicating osteoblastic differentiation. Cbfa1 expression was greatest in the region with an average strain 1312 me followed by a region on the strip subjected to just fluid shear without any tension. Cbfa1 expression was significantly greater in cells subjected to tensile forces than unstrained controls at all levels of strain tested (p< 0.05). Cbfa1 expression was further enhanced significantly by the addition of osteogenic factors (p< 0.05). Significantly greater mineralization (p< 0.05) occurred in the regions subject to tension with the greatest being in the region with an average strain of 1312 me. Conclusions: Mechanical tensile forces especially in the range of up to 2173me promote differentiation of Mesenchymal Stem Cells into osteoblasts and encourage expression of the Cbfa1 gene. Tensile strain also promotes mineralization. Chemical factors in form of osteogenic media accelerate the differentiation of MSCs and encourages earlier production of osteoblast specific markers. Fluid shear appears to have a beneficial effect in stimulating differentiation into the osteoblast phenotype and, combined with tensile strain, may offer an even greater osteogenic stimulus

The intra-articular supracondylar fractures of the femur are difficult fractures that occur with increasing frequency in the last years. Their complex management is a source of controversy, since surgical outcome is not acceptable in all instances. In the last 6 years we treated 30 comminuted intra-articular supracondylar fractures of the femur (type-C). The mean age was 28 years (17– 65 years). We made any effort to apply a method which could guarantee reduction and articular reconstruction, rigid fixation and bridging of metaphysic-epiphysis, in order to achieve early mobilization and to avoid post-traumatic osteoarthritic lesions. The extra-articular portion of the fractures was fixed using DCS, condylar plates, Ô plates and in some cases the whole construct was protected by an external fixation device. In some other cases, stability was enhanced using a second bridging plate in the medial side or applying a massive cortical graft properly adapted and fixed to the plate. The articular surface was reconstructed using cancellous lag-screws. Intra-articular epiphyseal portions were regularly bone grafted when there was comminution and bone loss, Bone grafting was also carried out in cases of meta-diaphyseal severe comminution and major bone defects. Clinical and radiological outcome was evaluated. Radiological parameters (axial valgus deformity, shortening, development of post-traumatic osteoarthritis etc.) were correlated to the method of surgical treatment. There were major complications (such as infection, especially in open fractures, delayed healing, hardware failure, refracture etc.). In some instances re-operation was necessary. In problematic C3 supracondylar fractures of the knee, poor surgical results are associated to early complications and development of degenerative lesions. This handicap is particularly is particularly important since it occurs in a major weight bearing joint of young patients. Using meticulous surgical technique (including bone-grafting, minimal devitalization of the fragments etc.), and choosing the most appropriate implant in every case, reconstruction can be performed reliably with good results and a low rate of complications

Background: Impaction bone-grafting in revision hip surgery generates high forces that may be transmitted through the graft to the femoral cortex, generating high surface strains and a concomitant risk of femoral fracture. Concern of inducing fracture may lead to under-compaction of the graft, with subsequent risk of implant migration. Vibration is commonly used in civil engineering applications to increase aggregate compressive and shear strengths. We have therefore examined the hypotheses that vibration-assisted graft compaction would (a) increase graft compaction compared with the standard femoral impaction grafting technique and subsequently reduce prosthesis migration and (b) reduce femoral hoop strains in the production of graft of a given density and mechanical properties. Method: Physiological composite femurs were adapted to represent femurs encountered in revision hip surgery by widening of the internal diameter and thinning of the outer shell. In the control group, revision with the standard Exeter technique was simulated using highly washed morcellised bone graft from fresh-frozen human femoral heads. In the study group, vibration-assisted graft compaction was used. The femurs were mounted on a 5kN capacity load cell to measure the total force imparted during graft impaction. Strain gauges placed at the medial calcar and midshaft, measured hoop strains generated during the impaction process. On completion of graft impaction, an Exeter stem was cemented in place. Implant subsidence under physiological cyclic loading (5x 105 cycles) and graft density using micro CT were measured after compaction. Results: There were no significant differences between the two groups in the peak forces (3.8-4.1kN) imparted during the impaction process. Similar peak hoop strains were observed in the both groups (1.2-1.4%). However a greater graft density was seen in the vibration group with minimal implant subsidence under cyclic loading. Conclusion: The use of vibration during the impaction process allowed improved graft compaction to be achieved without increasing hoop strains in the femoral cortex. This has implications in preventing failure from under impaction without increasing the risk of fracture. Furthermore, this analysis is applicable to the study of novel synthetic grafts / mixtures in the impaction process for orthopaedic application

Hybrid fixation is now an established modality of treatment for articular fractures of the proximal and distal tibia. However, there is a lack of consensus over the management of non-articular metaphyseal fractures extending into the diaphysis. Despite sophisticated techniques, intramedullary nailing remains difficult and has relatively high rates of malunion and nonunion. Plate fixation may produce satisfactory results, but its use is limited where there is major extension into the diaphysis or where the soft tissues are compromised. Since 1995, we have used hybrid external fixation in the treatment of such fractures in 24 male and 16 female patients of mean age 54 years (15 to 92). Mostly sustained in road traffic accidents, there were 26 closed and 14 open fractures, seven of which were Gustillo type IIIB. There were 26 distal tibial, seven proximal and seven tibial shaft fractures. Metaphyseal fixation consisted of two rings with tension wires, diaphyseal fixation of screws. We used additional rings in segmental diaphyseal fractures or used olive compression wires across the fracture when additional stability was required. Hybrid fixation was the primary procedure in 25 patients and a secondary procedure, performed within eight weeks of injury, in 15. All patients went on to union in a mean of 45 weeks, but 10 required additional procedures such as bone-grafting, additional insertion of olive wire and soft-tissue procedures. Residual malunion in six patients required adjustment with frame fixation, with minimal clinical significance. We had three pin-tract infections and one deep infection, which resolved after sequestrectomy. When choosing a fixation system, it must be taken into account that high-energy tibial fractures may be slow to unite and that deep infection is related to the degree of soft-tissue injury. We believe hybrid fixation is a safe and minimally invasive treatment option. Careful attention to reduction and soft-tissue management, followed by early functional rehabilitation, can reduce healing times