Fracture Fixation Devices Research Articles

Commentary on: Histologic, Molecular, and Clinical Evaluation of Explanted Breast Prostheses, Capsules, and Acellular Dermal Matrices for Bacteria.

“Extraordinary claims require extraordinary evidence”Carl Sagan1 The authors of this study have examined capsule, tissue expander (TE), and artificial dermal matrix (ADM) specimens obtained from 26 patients randomly selected from a group 147 women undergoing exchange procedures for definitive breast implants using a variety of histological, imaging, and molecular techniques to detect bacteria.2 Of these 26 patients, two patients demonstrated bacteria on a culture and scanning electron microscopy, respectively. The authors conclude based on these findings that “biofilms likely contribute to a proportion but not all diagnosed capsular contractures” (CC). In 1978, Costerton described his biofilm theory, postulating that bacteria adhere to available surfaces in glycocalyx-enclosed sessile masses and that this structure is the predominant state in natural, industrial, and, particularly, medical ecosystems.3 By doing so, he alerted the world to a new menace and forced a paradigm shift in the way we view infection. Prior to this, many chronic implant-associated inflammation was deemed “sterile” based on the inability to culture microorganisms using traditional microbiological techniques. The advent of sensitive detection and imaging techniques, however, has now established biofilm as the central cause of an increasing number of device-associated infections (DAI).4 Biofilm-related DAI has been reported in joint prostheses, penile prostheses, fracture fixation devices, intravenous and urinary catheters, peritoneal dialysis catheters, contact lenses, endoscopes, cardiovascular and biliary stents, neurosurgical prostheses, cochlear implants, and, pertinent to this study, breast implants.4 The difficulty with detecting biofilm in the clinical and research setting, however, cannot be underestimated. As the number of bacteria within a biofilm community only account for 15% of the total mass, the low numbers can be difficult to isolate.5 Additionally, the firm adherence of the protective glycoprotein matrix needs to be disrupted prior to release of these bacteria into culture medium for subsequent …

Percutaneous external fixator pins with bactericidal micron-thin sol–gel films for the prevention of pin tract infection

Risk of infection is considerable in open fractures, especially when fracture fixation devices are used to stabilize the fractured bones. Overall deep infection rates of 16.2% have been reported. The infection rate is even greater, up to 32.2%, with external fixation of femoral fractures. The use of percutaneous implants for certain clinical applications, such as percutaneous implants for external fracture fixation, still represents a challenge today.Currently, bone infections are very difficult to treat. Very potent antibiotics are needed, which creates the risk of irreversible damage to other organs, when the antibiotics are administered systemically. As such, controlled, local release is being pursued, but no such treatments are in clinical use. Herein, the use of bactericidal micron-thin sol–gel films on metallic fracture fixation pins is reported. The data demonstrates that triclosan (2,4,4′-trichloro-2′-hydroxydiphenylether), an antimicrobial agent, can be successfully incorporated into micron-thin sol–gel films deposited on percutaneous pins. The sol–gel films continuously release triclosan in vitro for durations exceeding 8 weeks (longest measured time point). The bactericidal effect of the micron-thin sol–gel films follows from both in vitro and in vivo studies. Inserting percutaneous pins in distal rabbit tibiae, there were no signs of infection around implants coated with a micron-thin sol–gel/triclosan film. Healing had progressed normally, bone tissue growth was normal and there was no epithelial downgrowth. This result was in contrast with the results in rabbits that received control, uncoated percutaneous pins, in which abundant signs of infection and epithelial downgrowth were observed. Thus, well-adherent, micron-thin sol–gel films laden with a bactericidal molecule successfully prevented pin tract infection.

The Problem of Fracture Fixation Augmentation and Description of a Novel Technique and Implant for Femoral Neck Stabilization

Fracture augmentation for osteopenic bone is a widely accepted concept but not commonly used due to the difficulty with application of the materials in conjunction with surgical implants in fracture repair. Until recently there was little choice of materials for augmentation, but new formulations of structural orthobiological matrix (SOM) have been developed, which have better flow and setting properties than the original polymethylmethacrylate and calcium phosphate ceramics materials. In addition, a new class of injectable implants with the ability to deliver some of these newer SOMs has been designed and received regulatory clearance as fracture fixation devices. This cadaveric study was undertaken to assess the feasibility of using the N-Force Fixation System in a femoral neck fracture model with 6 different SOMs. A new property of SOM was discovered regarding the flow characteristics of the tested materials within the proximal femur. Intrusion and extrusion characteristics were observed and were SOM specific. C-arm fluoroscopy and CT studies revealed the ability of intrusion-type SOM to intrude into cancellous bone trabeculae and minimize the chance of joint extrusion through fracture lines, whereas extrusion-type SOM would not intrude into trabecular spaces and demonstrated a tendency for fracture site extrusion and fracture contact interposition, risking compromise of fracture healing and angiogenesis. The instrumentation and implants gave reproducible implant placement and SOM delivery with low-pressure application and circumferential augmentation from the near cortex extending into the femoral neck and head in a tapering cone-type pattern.

Applications of Titania Nanotubes in Bone Biology.

Orthopedic implants, including artificial joints and fracture fixation devices, have helped to restore the physical independence of many patients, thereby improving the quality of their lives. Titania (Ti) and its alloys are better implant materials than stainless steel and Co-Cr alloys owing to their superior mechanical properties and biocompatibility; however, Ti-based implants may sometimes fail, leading to repeated surgeries. With the recent advancements in nanotechnology, the nanosurface modifications of Ti, especially in the form of Ti nanotubes (TNTs), have drastically improved the properties of orthopedic implants. In this review, we have summarized the fabrication of Ti nanotubes by electrochemical anodization and their influence on osteoblast cells and staphylococcus aureus. In addition, we have discussed the corrosion resistance of Ti nanotubes.

Plate or nail for distal tibia fractures: Is there a clear answer?

Controversy still exists about the relative merits of the fixation devices for distal tibia fractures, and decision making remains difficult. This study aims to answer the question and find out when each implant is preferred. Of the patients treated at our hospitals for distal tibia fractures, 30 patients treated by minimally invasive plate osteosynthesis (MIPO) (group A) were matched to 30 patients treated by static reamed intramedullary nail (SR-IMN) (group B), with regard to age decade, gender, fracture type (open or closed), the AO/OTA classification of the fracture, and occupation category. No significant difference was found between the two groups regarding bone union and complications including angulation of >5°, shortening of >1 cm, implant failure, fixation loss, or deep infection. Group A had a shorter mean operative time and mean radiation exposure time. Group B had a shorter mean time from trauma to surgery and faster full weight-bearing, radiographic union, and return to work. Only three patients lost their previous job, two in group A and one in group B. Both implants are useful and effective. The clear answer is that no best implant and preoperative planning is the cornerstone to determine the patient, fracture, and surgeon factors that give priority for one implant over the other.

Novel intramedullary-fixation technique for long bone fragility fractures using bioresorbable materials.

Almost all of the currently available fracture fixation devices for metaphyseal fragility fractures are made of hard metals, which carry a high risk of implant-related complications such as implant cutout in severely osteoporotic patients. We developed a novel fracture fixation technique (intramedullary-fixation with biodegradable materials; IM-BM) for severely weakened long bones using three different non-metallic biomaterials, a poly(l-lactide) (PLLA) woven tube, a nonwoven polyhydroxyalkanoates (PHA) fiber mat, and an injectable calcium phosphate cement (CPC). The purpose of this work was to evaluate the feasibility of IM-BM with mechanical testing as well as with an animal experiment. To perform mechanical testing, we fixed two longitudinal acrylic pipes with four different methods, and used them for a three-point bending test (N = 5). The three-point bending test revealed that the average fracture energy for the IM-BM group (PLLA + CPC + PHA) was 3 times greater than that of PLLA + CPC group, and 60 to 200 times greater than that of CPC + PHA group and CPC group. Using an osteoporotic rabbit distal femur incomplete fracture model, sixteen rabbits were randomly allocated into four experimental groups (IM-BM group, PLLA + CPC group, CPC group, Kirschner wire (K-wire) group). No rabbit in the IM-BM group suffered fracture displacement even under full weight bearing. In contrast, two rabbits in the PLLA + CPC group, three rabbits in the CPC group, and three rabbits in the K-wire group suffered fracture displacement within the first postoperative week. The present work demonstrated that IM-BM was strong enough to reinforce and stabilize incomplete fractures with both mechanical testing and an animal experiment even in the distal thigh, where bone is exposed to the highest bending and torsional stresses in the body. IM-BM can be one treatment option for those with severe osteoporosis.

Bactericidal micron-thin sol-gel films prevent pin tract and periprosthetic infection.

Orthopedic injuries constitute the majority of wounds sustained by U.S. soldiers in recent conflicts. The risk of infection is considerable with fracture fixation devices. In this pilot study, we examined the use of unique bactericidal micron-thin sol-gel films on fracture fixation devices and their ability to prevent and eradicate infections. External fixation was studied with micron-thin sol-gel coated percutaneous pins releasing triclosan and inserted medially into rabbit tibiae. A total of 11 rabbits received percutaneous pins that were either uncoated or sol-gel/triclosan coated. Internal fracture fixation was also studied using sol-gel coated intramedullary (IM) nails releasing vancomycin in the intramedullary tibiae. Six sheep received IM nails that were coated with a sol-gel film that either contained vancomycin or did not contain vancomycin. All animals were challenged with Staphylococcus aureus around the implant. Animals were euthanized at 1 month postoperative. Rabbits receiving triclosan/sol-gel coated percutaneous pins did not show signs of infection. Uncoated percutaneous pins had a significantly higher infection rate. In the sheep study, there were no radiographic signs of osteomyelitis with vancomycin/sol-gel coated IM nails, in contrast to the observations in the control cohort. Hence, the nanostructured sol-gel controlled release technology offers the promise of a reliable and continuous delivery system of bactericidals from orthopedic devices to prevent and treat infection.

The use of silk-based devices for fracture fixation

Metallic fixation systems are currently the gold standard for fracture fixation but have problems including stress shielding, palpability and temperature sensitivity. Recently, resorbable systems have gained interest because they avoid removal and may improve bone remodelling due to the lack of stress shielding. However, their use is limited to paediatric craniofacial procedures mainly due to the laborious implantation requirements. Here we prepare and characterize a new family of resorbable screws prepared from silk fibroin for craniofacial fracture repair. In vivo assessment in rat femurs shows the screws to be self-tapping, remain fixed in the bone for 4 and 8 weeks, exhibit biocompatibility and promote bone remodelling. The silk-based devices compare favourably with current poly-lactic-co-glycolic acid fixation systems, however, silk-based devices offer numerous advantages including ease of implantation, conformal fit to the repair site, sterilization by autoclaving and minimal inflammatory response.

Clavicular hook plate may induce subacromial shoulder impingement and rotator cuff lesion - dynamic sonographic evaluation

BackgroundClavicular hook plates are effective fixation devices for distal clavicle fractures and severe acromioclavicular joint dislocations. However, increasing number of studies has revealed that subacromial portion of the hook may induce acromial bony erosion, shoulder impingement, or even rotator cuff damage. By sonographic evaluation, we thus intended to determine whether the presence of hook plate may induce subacromial shoulder impingement and its relationship relative to surrounding subacromial structures.MethodsWe prospectively followed 40 patients with either distal clavicle fracture or acromioclavicular joint dislocation that had surgery using the Arbeitsgemeinschaft für Osteosynthesefragen (AO) clavicular hook plate. All patients were evaluated by monthly clinical and radiographic examinations. Static and dynamic musculoskeletal sonography examinations were performed at final follow-up before implant removal. Clinical results for pain, shoulder function, and range of motion were evaluated using Constant-Murley and Disability of Arm, Shoulder, and Hand (DASH) scores.ResultsClinically, 15 out of 40 patients (37.5%) presented with subacromial impingement syndrome and their functional scores were poorer than the non-impinged patients. Among them, six patients were noted to have rotator cuff lesion. Acromial erosion caused by hook pressure developed in 20 patients (50%).ConclusionsWe demonstrated by musculoskeletal sonography that clavicular hook plate caused subacromial shoulder impingement and rotator cuff lesion. The data also suggest an association between hardware-induced impingement and poorer functional scores. To our knowledge, the only solution is removal of the implant after bony consolidation/ligamentous healing has taken place. Thus, we advocate the removal of the implant as soon as bony union and/or ligamentous healing is achieved.

Metal Hypersensitivity in Patients with Conventional Orthopaedic Implants.

Metal implants are widely used in orthopaedic surgery for elective joint arthroplasty or fracture fixation. Metal alloys also are widely used in other medical specialties for devices such as dental implants, cardiovascular stents, and gastrointestinal wire mesh stents. Metal hypersensitivity, as detected with skin patch testing, is common, with a prevalence of between 10% to 17% in the general population1-5. This raises the concern that hypersensitivity reactions may occur in patients with metallic orthopaedic implants and the possibility that metal hypersensitivity reactions may account for ongoing pain or aseptic loosening following joint arthroplasty6,7. The purpose of the present review is to examine the current understanding of metal hypersensitivity and its potential clinical importance in orthopaedic surgery. The methods of testing for metal hypersensitivity and the limitations of such tests are also discussed. In this article, we consider conventional arthroplasty implants (metal-polyethylene and metal-ceramic articulations) and fracture-fixation devices. Coverage of the localized reactions reported in association with metal-on-metal arthroplasty is beyond …

Анализ напряженно-деформированного состояния дистального отдела голени и стопы при повреждениях pilon в условиях наружной фиксации при помощи стержневых аппаратов

Цель исследования — выявить возможности применения стержневых устройств для внеочагового остеосинтеза при повреждениях pilon и установить наиболее подходящие конструкции для данной локализации повреждений. Для этого в условиях лаборатории биомеханики ГУ «Институт патологии позвоночника и суставов им. проф. М.И. Ситенко АМН Украины» использован анализ напряженно-деформированного состояния дистального отдела голени и голеностопного сустава в норме и в условиях внеочаговой фиксации разными типами стержневых аппаратов при переломах pilon. Анализ проведен методом конечных элементов, который дает возможность в полной мере учитывать геометрические и физические особенности конструкций, а также предоставить полную картину нагрузки, провести объективное сравнение методов и устройств для фиксации переломов, оценить их преимущества и недостатки.Исследование проведено на объемной трехмерной модели дистального отдела голени и голеностопного сустава с применением трехмерной конечно-элементной модели. Расчеты проведены с применением расчетной программы BioCаd и программы визуализации расчетов Looker.В результате определены наиболее нагруженные участки исследуемой анатомической зоны в норме и распределение нагрузок в условиях внеочаговой фиксации при переломах pilon. Дказано, что применение стержневых односторонних устройств при переломах pilon в принципе возможно, так как обеспечивает разгрузку поврежденной анатомической зоны в условиях осевых нагрузок в границах половины массы тела человека, выделены конструкции фиксаторов, которым следует отдавать предпочтение.

UJI BIOKOMPATIBILITAS KOMPOSIT POLIVINIL ALKOHOLHIDROKSIAPATIT DENGAN PENGUAT CATGUT SEBAGAI BAHAN PENYAMBUNG PATAH TULANG

Bone fracture fixation devices have been using rigid metallic materials such as titanium, titanium-alloy or cobalt chrome. Besides having some advantages, the titanium fixation devices also have disadvantages, such as too high strength and stiffness. This continuously stimulates the bone, causing bone atrophy under the plate, further disrupting the growth of bones, especially in children. Other deficiencies of this metal material is its sensitivity to temperature changes and the spread of metal ions in several organs. Some of these shortcomings led to the need for a secondary operation. Bone fracture fixation devices, such as the poly-l-lactic acid (PLLA), can be absorbed by the body and show some other advantages. However, it also has some drawbacks due to the high crystalline products during the degradation process. Lactic acid monomer released after degradation causes cellular response at the implant site, which facilitates the release of chemical mediators, such as prostaglandine by fibroblasts and macrophages as a cause of bone resorption. Therefore, this study aimed to develop the use of other polymeric materials that have good biocompatibility,appropriate mechanical strength, and can be absorbed by the body, such as Polyvinyl Alcohol (PVA). Previous research suggests that the PVA-HA composite with catgut reinforcement has sufficient and stable mechanical strength to be used as bone fracture fixation material. The purpose of this study is to know whether the PVA-HA composite with catgut reinforcement has good biocompatibility without toxicity and hypersensitivity effects in experimental animals. Biocompatibility testing includes local cytotoxicity and type IV contact hypersensitivity test. This type of research is experimental in vivo laboratory using wistar rats (Rattus norvegicus). Testing is done through two phases, in which induction or sensitization phase is done by rubbing PVA-HA composite with catgut reinforced ointment powder on the ears that lasts up to 10 days. After being rested for 3 days, this is followed by a second phase contact (elicitation) on day 14 and observed in the period of 24, 48, and 72 hours. Observations were made macroscopically and ear thickness was measured with a micrometer. Local toxicity testing is done by implantation of PVA-HA composite with catgut reinforcement on the back catgut of wistar rats. After a certain time period, the implant material is opened,examined, and observed histologically under a light microscope. The results showed no discoloration or induration on the animal ears in all treatment and control groups, both for the sensitization and the elicitation phase. One way ANOVA statistical test showed that there were no significant differences in the results of measurements of the thickness of the wistar rats ears from all treatment groups before and after treatment on measures 24, 48 and 72 hours (ρ >0.05). Microscopic examination showed no infiltration of acute inflammatory cells such as neutrophils, basophils or eusinofil, and chronic inflammatory cell infiltration such as macrophages, lymphocytes and plasma cells. It can be concluded that the PVA-HA composite with catgut reinforcement is a material that does not cause toxicity and hypersensitivity in experimental animals, thus potentially can be used as bone fractures fixation material.

EFFECT OF IMMERSION TIME TO MECHANICAL STRENGTH OF POLYVINYL ALCOHOL– HYDROXY APATITE COMPOSITE AS BIODEGRADABLE BONE PLATE

Polymer based material such as Poly-L-Lactic-Acid (PLLA) have been used for titanium substitution. However, the last research indicates that it was not an ideal material as bone fracture fixation device. It is a challenge to develop other materials as biodegradable bone plate for titanium substitution, such as polyvinyl alcohol (PVA). In this study, polyvinyl alcohol has composited with Hydroxy apatite (HA) and reinforced with catgut fiber. The aim of this study was to know the effect of immersion time to mechanical strength of PVA– HA composite with catgut reinforced as biodegradable bone plate after biodegradation test for 30 and 60 days. Specimens were prepared for tensile and bending strength tests, immersed in phosphate buffered saline (PBS) solution with pH 7.4 at 370C. Specimens were weighed before and after biodegradation test, tensile and bending test were done after removed for 30 and 60 days. The result showed that PVAHA composite reinforced with catgut fiber has stable mechanical strength after 30 and 60 days biodegradation process. The mechanical strength decreased in 30 and 60 days in all intervention groups, but it still has adequate mechanical strength as biodegradable bone plate. In conclusion, PVA-HA composite reinforced with catgut fiber can be developed as biodegradable bone plate replace titanium and other commercial bone plate.

Clinical and functional outcomes of internal fixation with intertrochanteric antegrade nail in older patients with proximal extracapsular femoral fractures.

The intertrochanteric Trigen Intertan(®) nail (Smith & Nephew, Memphis, TN) is a popular fixation device for proximal extracapsular femoral fractures (PEFFs). We evaluated clinical and functional outcomes in patients with PEFFs treated with Trigen Intertan(®) nail. In a single-site, prospective observational study, clinical and functional parameters were recorded for all patients admitted to the Emergency Department with PEFFs from June 2008 through June 2011. Patients with severe cognitive impairment, severe disability, neoplastic pathological fractures, or suffering from terminal illnesses were not eligible for the study. Fractures were classified according to the AO/OTA classification system. Preoperative physical fitness was assessed via the American Association of Anaesthetists (ASA) score. The Barthel index was used to quantify the level of physical function before fracture and at follow-up. One-hundred thirty-five patients with PEFFs were eligible for inclusion during the 3-year survey (mean age 83.2±9.5years; 82% females). Fracture type distribution was as follows: A1.1=18%, A1.2=7%, A1.3=5%, A2.1=44%, A2.2=21%, A2.3=5%. All patients were treated with Trigen Intertan(®) nail. Two patients experienced a fracture of the femoral shaft during the insertion of a long nail for an A2.3 fracture. Weight-bearing was allowed between the third and tenth postoperative day depending on pain tolerance and general conditions. No loss of reduction, collapse of the femoral neck, nonunion or fixation failure were observed. Two patients died within 10days postoperatively, and nine within 6months after surgery. Functional status 1month after surgery was lower than pre-fractural levels, and improved over follow-up. At 6months, functional status was comparable to the pre-fractural level. Trigen Intertan(®) produces highly satisfactory clinical and functional results in older patients with PEFFs. Complete functional recovery is obtained on average 6months after surgery.

PLLA/HA Composite Laminates

A composite material may be done in such a way that the final product may acquire some excellent properties that cannot be found individually in either material. Novel PLLA/HA multilayer composites are fabricated with different HA contents and sequence of stacking with the goal to produce devices for bone fracture fixation. Hydroxyapatite powder particles act as flaws in the continuous polymer matrix due to limited interfacial bonding with the polymer matrix and a limited effect on toughening mechanisms.

Cytocompatibility assessment of chemical surface treatments for phosphate glass to improve adhesion between glass and polyester

Fully resorbable phosphate glass fiber reinforced polymer composites have shown real potential for replacing some of the existing metallic bone fracture fixation devices. However, some of these composites have not provided suitable mechanical strength profiles over the required healing period for bone. Typically, it has been seen that these composites can lose up to 50% or more of their strength within the first week of degradation. Functionalizing the glass surface to promote polymer adhesion or to introduce hydrophobicity at the glass surface could potentially introduce control over the mechanical properties of the composite and their retention. In this study eight chemical agents namely, Glycerol 2-phosphate disodium salt; 3-phosphonopropionic acid; 3-aminopropyltriethoxy silane; etidronic acid; hexamethylene diisocyanate; sorbitol/sodium ended PLA oligomers and amino phosphonic acid, were selected to functionalise the bulk phosphate glass surface. Selected chemical agents had one functional group (-OH or O C N) to react with the glass and another functionality (either -OH, NH2, or Na) to react with the polymer matrix and/or produce hydrophobicity at the fiber surface. Bulk phosphate glass surface-treated with the above agents were assessed for the cytotoxicity of degradation products cell-material interaction in short- and long-term direct cytocompatibility studies. Results obtained from these cytocompatibility studies (using human osteosarcoma (MG63) and primary human osteoblast cell lines) revealed no cytotoxicity from the degradation products and a response comparable to controls in terms of cell functions (attachment, viability, metabolic activity, proliferation, and differentiation) and morphology.

Treatment of distal tibia metaphyseal fractures; plating versus intramedullary nailing: A systematic review of recent evidence

Treatment of distal tibia metaphyseal fractures is challenging. The purpose of this study was to systematically review the recent literature regarding management of extra-articular distal tibia fractures with a view to compare the outcome of intramedullary nailing with plate fixation. Advanced literature search was performed using Medline (Ovid), Embase (Ovid) and Cochrane databases. Data were extracted regarding number of participants, fracture fixation devices, percentage of open fractures, malunions, nonunions, wound infections and metal removal etc. After inclusion, exclusion criteria, two RCTs and four retrospective comparative studies were deemed suitable for this review. The overall results showed relatively higher rate of infection in plating group as compared to intramedullary nailing. However malalignment was more common with intramedullary nailing. Both techniques can provide adequate treatments in appropriately selected patients. None of the studies had sufficient power to show clinically significant difference. Further studies are required to compare new locking plates with intramedullary nails.

Comparison of the Cable Pin System With Conventional Open Surgery for Transverse Patella Fractures

The cable pin system is an effective device for fixation of transverse patella fractures. However, whether this device provides superior results using a minimally invasive technique instead of conventional open surgery using the K wire tension band method is unclear. We asked whether a minimally invasive technique would be associated with (1) increased operative time; (2) reduced postoperative pain; (3) faster recovery of ROM; (4) higher knee scores; and (5) reduced complications. Forty patients with displaced transverse fractures of the patella participated in this prospective, randomized, controlled trial. Twenty of these patients underwent a minimally invasive technique and the others had conventional open surgery using K wires. Some data for six of the 20 patients who underwent the minimally invasive technique were published in an earlier prospective, observational trial. At postoperative intervals of 1, 3, 6, 12, and 24 months, pain was measured by VAS scores, active flexion and extension of the knee were measured in degrees by goniometry, and knee function was evaluated using the Böstman clinical grading scale. Operative time was longer in the minimally invasive surgery group (54.3 ± 9.8 minutes versus 48.5 ± 6.1 minutes). Pain scores were better (lower) in the minimally invasive surgery group at 1 and 3 months but not at 6 months. Early flexion, ultimate flexion, and knee scores from 3 to 24 months, likewise, were better in the minimally invasive surgery group. Complications mostly related to symptomatic hardware were less common in the minimally invasive surgery group. The minimally invasive technique is superior to conventional open surgery using K wires in terms of less early postoperative pain, better mobility angles of the injured knee, higher functional score of the injured knee, and decreased incidence of complications. Level I, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Locking-plate osteosynthesis versus intramedullary nailing for fixation of olecranon fractures: a biomechanical study

Intramedullary nailing and locked plating for fixation of olecranon fractures has recently gained popularity. However, these two new technologies have not been compared for their biomechanical efficacy. The aim of this study was to evaluate the biomechanical stability of two newly designed fracture fixation devices for treating olecranon fractures during dynamic continuous loading: the ION intramedullary locking nail and the LCP precontoured locking compression plate. Simulated oblique olecranon fractures were created in eight pairs of fresh-frozen cadaver ulnae and stabilised using either the LCP or ION. Specimens were then subjected to continuous dynamic loading (from 25 to 200N), with a continuous angle alteration between 0° and 90° of flexion, to perform a matched-pairs comparison. Significant differences in the distance between markers surrounding the fracture gap was determined using the Wilcoxon test after four and 300 loading cycles. The ION resulted in significantly less displacement in the fracture gap at 0° extension (P = 0.036), 45° flexion (P = 0.035) and 90° flexion (P = 0.017) after 300 cycles of continuous loading. The measured displacements were small and were probably not of clinical significance. No mechanical failure or hardware migration was seen with either fixation technique. This study shows significantly less micromotion for the ION than for the LCP in treating oblique olecranon fractures after 300 cycles of dynamic loading. Both implant types could be appropriate surgical techniques for fixation of selected olecranon fractures and osteotomies.

Salvage Hip Arthroplasty After Failed Fixation of Proximal Femur Fractures

We reviewed 46 patients who underwent salvage hip arthroplasty (SHA) for revision of failed cannulated screws (CS), sliding hip screws (SHS), or intramedullary nails (IMN). The primary objective was to determine differences in operative difficulty. SHA after failed femoral neck fixation was associated with lower intra-operative demands than after failed peri-trochanteric fractures. Similarly, analysis by the index implant found that conversion arthroplasty after failed CSs was associated with lower intra-operative morbidity than failed SHSs or IMNs; differences between SHS and IMN were not as clear. Importantly, intra-operative data in cases of failed SHSs were similar regardless of the original fracture type, showing the device played a larger role than the fracture pattern. Complications and revision surgery rates were similar regardless of fracture type or fixation device. Our results suggest that operative demands and subsequent patient morbidity are more dependent on the index device than the fracture pattern during SHA.