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Fracture of the tibial plafond, such as in a trimalleolar fracture, with a large posterior tibial (posterior malleolus) fragment may require open reduction and internal fixation. Anatomic reduction of the articular surface can be ensured by visualizing the articular surface using an arthroscope during reduction. Four cases wherein this technique has proven effective are described.
Compression, distraction, and torsion stiffness of the Ilizarov external fixator was measured in two fracture models in autopsy specimens of tibia and fibula. A transverse model was tested in six frame constructions with the osteotomy site preloaded in four different positions. An oblique model was tested in four frame constructions also with four preloaded positions. Stiffness was more dependent on bone preload than wire number, wire type, or frame design. High stiffness was achieved by bone preloading, by compressing the rings together, by increasing the number of wires, and by using olive wires. The stiffness can be decreased (dynamization) by separating the rings and by removing wires. This data is helpful for frame design of the Ilizarov fixator.
Ankle fractures are common injuries and commonly require operative stabilisation. The aim of ankle fracture fixation should be reduction and stabilisation, as for any periarticular fracture. Anatomical reduction will lead to good long-term results, but non-anatomically reduced fractures will lead to a poor functional outcome and development of osteoarthritis. We reviewed eight cases of non-anatomical ankle fixations that were revised by M.D. over a 4-year period. All were revised within 1 year of initial fixation. Clinical scoring for functional outcome was performed using the American Orthopaedic Foot and Ankle Society rating system for the ankle and hindfoot. All patients reported improved function after the revision procedure. We conclude that revision surgery is justified if suboptimal fixation is encountered within 12 months of the original surgery.
UNLABELLED: Fat-embolism syndrome and pulmonary dysfunction may develop in multiply injured patients who have a fracture of a long bone. Although early fixation of a fracture is beneficial, intramedullary nailing may exacerbate pulmonary dysfunction by causing additional embolization of marrow fat. We examined the pulmonary effects of the timing and method of fixation of a fracture in a canine fat-embolism model. Fat embolism was induced in forty-one adult dogs by reaming the ipsilateral femur and tibia followed by pressurization of the intramedullary canal. The animals were divided into a control group of eight dogs that had induction of fat embolism alone and an experimental group of thirty-three dogs that had induction of fat embolism and internal fixation of a transverse fracture of the middle of the contralateral femoral shaft. In the control group, four dogs each were killed four hours and twenty-four hours after induction of fat embolism. In the experimental group, a femoral fracture was created and fixation was performed four hours after embolic showering in fifteen animals and twenty-four hours after embolization in eighteen animals. The two experimental groups were subdivided according to the method of fixation of the fracture: eleven dogs each had application of a plate, nailing without reaming, and nailing with reaming. The pulmonary arterial pressure and the alveolar-arterial gradient were measured preoperatively, during induction of fat embolism, and as long as one hour after fixation of the fracture but before the animal was killed. The lungs, brain, and kidneys were examined for pathological and physiological evidence of intravascular fat. The intravascular fat persisted for twenty-four hours after induction of pulmonary fat embolism. Pulmonary arterial pressure remained elevated at four hours after the embolic showering, before creation and fixation of the fracture. By twenty-four hours after the induction of fat embolism, pulmonary arterial pressure had returned to the baseline level. Neither the creation nor the fixation of the fracture affected pulmonary arterial pressure. In the animals that had fixation of a fracture four hours after embolization, both nailing with reaming and nailing without reaming produced alveolar-arterial gradients that were higher than the baseline values, whereas fixation with a plate did not change the alveolar-arterial gradient significantly from the baseline value. In addition, the alveolar-arterial gradients in the animals that had nailing with reaming and nailing without reaming four hours after embolization were, respectively, four and 3.5 times higher than that in the animals that had fixation of the femur with a plate. In the animals that had fixation twenty-four hours after embolization, none of the methods for fixation affected the alveolar-arterial gradient. The amount of embolic fat in the lungs, brain, and kidneys was not affected by fixation of the fracture when it was performed at either the four-hour or the twenty-four-hour time-interval. Scores for pulmonary edema were increased by fixation of the fracture, but there was no difference among the scores associated with the three methods of fixation. CLINICAL RELEVANCE: The findings of the present study indicated that the amount of intravascular fat persisting in the lungs, kidneys, and brain twenty-four hours after pressurization of the intramedullary canal is not affected by the method of fixation of the fracture. Fixation of a fracture is associated with minimum evidence of acute inflammation and has no effect on pulmonary artery pressure. The development of pulmonary dysfunction from fat emboli depends on other factors, not just on the presence of fat in pulmonary vessels. It appears that the method of fracture fixation has little influence on the outcome of treatment.
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In the internal fixation of fractured bone by means of bone-plates fastened to the bone on its tensile surface, an on-going concern has been the excessive stress shielding of the bone by the excessively-stiff stainless-steel plate. The compressive stress shielding at the fracture-interface immediately after fracture-fixation delays callus formation and bone healing. Likewise, the tensile stress shielding in the layer of bone underneath the plate can cause osteoporosis and decrease in tensile strength of this layer. In this study a novel forearm internal fracture fixation plate made from short carbon fibre reinforced plastic (CFRP) was used in an attempt to address the problem. Accordingly, it has been possible to analyse the stress distribution in the composite plates using finite-element modelling. A three-dimensional, quarter-symmetric finite element model was generated for the plate system. The stress state in the underlying bone was examined for several loading conditions. Based on the analytical results the composite plate system is likely to reduce stress-shielding effects at the fracture site when subjected to bending and torsional loads. The design of the plate was further optimised by reducing the width around the innermost holes.
A mode of treatment for femoral neck fracture with the use of Zespol plate and two AO screws is presented. Seventeen patients from 32 to 89 years of age have been operated. The method employed allowed for early mobilization and further rehabilitation of the patients.
Intramedullary (IM) fracture fixation serves to stabilize fracture fragments and maintains alignment, while permitting motion at the fracture site during functional activities. Acting as an internal splint, the implant serves as a load-sharing device and fracture healing progresses with the formation of peripheral callus. By allowing motion of adjacent joints, rehabilitation is concurrent with treatment, and stress-shielding is thought to be minimal using these techniques. Recently, IM nails have been introduced to widen indications for their use based on variations in the cross-sectional geometry, length and shape of nails, interlocking designs, and surgical techniques. Although the most important mechanical factors in the design of IM nails are strength, stiffness, and rigidity, anatomic constraints and surgical technique limit nail variations. Closed nailing is preferred to open procedures to preserve periosteal blood supply and minimize surgical trauma adjacent to the fracture. Blood flow to the fractured bone is elevated in nailing experiments, although callus maturation is somewhat delayed. However, the end result in terms of healing was similar to that of plate fixation.
BACKGROUND: In the internal fixation of fractured bone by means of bone-plates fastened to the bone on its tensile surface, an on-going concern has been the excessive stress-shielding of the bone by the excessively-stiff stainless-steel plate. The compressive stress-shielding at the fracture-interface immediately after fracture-fixation delays callus formation and bone healing. Likewise, the tensile stress-shielding of the layer of the bone underneath the plate can cause osteoporosis and decrease in tensile strength of this layer. METHOD: In order to address this problem, we propose to use stiffness-graded plates. Accordingly, we have computed (by finite-element analysis) the stress distribution in the fractured bone fixed by composite plates, whose stiffness is graded both longitudinally and transversely. RESULTS: It can be seen that the stiffness-graded composite-plates cause less stress-shielding (as an example: at 50% of the healing stage, stress at the fracture interface is compressive in nature i.e. 0.002 GPa for stainless steel plate whereas stiffness graded plates provides tensile stress of 0.002 GPa. This means that stiffness graded plate is allowing the 50% healed bone to participate in loadings). Stiffness-graded plates are more flexible, and hence permit more bending of the fractured bone. This results in higher compressive stresses induced at the fractured faces accelerate bone-healing. On the other hand, away from the fracture interface the reduced stiffness and elastic modulus of the plate causes the neutral axis of the composite structure to be lowered into the bone resulting in the higher tensile stress in the bone-layer underneath the plate, wherein is conducive to the bone preserving its tensile strength. CONCLUSION: Stiffness graded plates (with in-built variable stiffness) are deemed to offer less stress-shielding to the bone, providing higher compressive stress at the fractured interface (to induce accelerated healing) as well as higher tensile stress in the intact portion of the bone (to prevent bone remodeling and osteoporosis).
One hundred ninety eight adult patients who had sustained long bone fractures were treated by external fixation from admission to bone healing and consolidation. Of these, 135 had sustained high-energy injuries, 39 of them had suffered multi-system injuries. Superficial pin track infection was the most common complication, occurring predominantly in pins located in the femur, upper tibia and upper humerus. There were no cases of deep infection or osteomyelitis. One patient with a femoral shaft fracture developed a DVT although he was on preventive low molecular weight heparin, i.e. sc Clexane 40 mg daily. There were no cases of PE or ARDS. External fixation systems are a minimal invasive surgical modality, which allow three-dimensional fracture fixation after closed or minimal open reduction. They require a good command of surgical anatomy, but provide an optimal preservation of the fracture's soft tissue envelope, the critical biological factor for new bone formation and fracture healing. Recent publications have suggested that in the critically ill patient, minimally invasive fracture fixation surgery may prevent the perpetuation of a reactive, life threatening inflammatory reaction (the "second hit") which may induce the development of multiple organ dysfunction (MODS).
Intramedullary nailing is fracture fixation for long bone fractures. The fixation system is stabilization at fracture site, using a metal rod, from the inside of medullary cavity of long tubular bone. This principle of fracture fixation is intramedullary splinting. The procedures of fixation are reduction at fracture site, decision of entry point, reaming, insertion of nail and interlocking screw fixation, additionally controlling of dynamization for acceleration of fracture healing. The development of intremadullary nailing has sequentially addressed the design of nail, fixation system and technical exploitation, and expanding of indication. This paper introduces the concept and recent development of intramedullary nailing.
Temporal distribution of intramembranous and endochondral bone formation was studied in experimental fracture defects in rats under different stability of fracture fixation and fracture environments. Animals were surgically treated with a specially developed external fixation construct: Group 1 had 42 rats with a 0-mm fracture gap with bone ends touching corresponding to an axial stiffness of 265.00 +/- 34.00 N/mm and Group 2 had 42 rats with a 2-mm fracture gap corresponding to an axial stiffness of 30.38+/- 2.07 N/mm. From each group, six animals were sacrificed at 4 days and 1, 2, 3, 4, 6, and 12 weeks. Qualitative histologic and morphometric analyses revealed that less fixation rigidity and increased fracture gap induces a later response of bone formation and greater endochondral bone formation leading to prolonged time for full ossification. Furthermore, in the early phase of fracture healing temporal distribution and histologic characteristics of periosteal and intramedullary bone formation are similar and not influenced by rigidity and fracture environment. Results also showed that if tissues associated with the intramedullary region are preserved, intramedullary bone formation is substantial. Finally, histologic data indicate that woven bone might be a prerequisite for the differentiation process of endochondral bone formation.
OBJECTIVES: The purpose of this study was to investigate the mechanical strength and durability of intramedullary nailing (IM) and percutaneous pinning (PP) for fixation of three-part proximal humeral fractures using a cadaveric model. DESIGN: Three-part surgical neck fractures were created in paired embalmed cadaveric humeri. Fractures were fixed with IM and PP fixation. The fixation stiffness and durability was assessed under cyclic rotational loading (infraspinatus) ramping from 0.1 to 1.25 Newton-meters for 10,000 cycles. The specimen were then torsionally loaded to failure. SETTING: Mechanical testing was performed using a servohydraulic test system (MTS, Minneapolis, MN, U.S.A.). INTERVENTION: PP fixations were accomplished using standard multiplane techniques. IM fixation was attained using an 11.0-millimeter-diameter curved rod interlocked proximally with three splayed 5.0-millimeter cancellous screws and distally with three 3.5-millimeter cortical screws. MAIN OUTCOME MEASUREMENTS: During cyclic loading the reconstruction stiffness, angular migration, and angular displacement per cycle were measured and compared between fixation methods. The ultimate torque at failure, absolute angular migration, and reconstruction stiffness during failure were recorded and compared between fixation methods during destructive testing. RESULTS: The intramedullary device had greater stiffness and less angular displacement of fragments during cyclic loading. When loading the reconstructions to failure, the intramedullary device proved to have greater failure torques, stiffness, energy absorbed, and angular displacement before failure. CONCLUSIONS: This biomechanical study showed that the IM device provided a stronger, more stable, and durable fixation option than did PP fixation for large-fragment multipart proximal humeral fractures with minimal comminution.
The basic goal of fracture fixation is to stabilize the fractured bone, to enable fast healing of the injured bone, and to return early mobility and full function of the injured extremity. Fractures can be treated conservatively or with external and internal fixation. Conservative fracture treatment consists of closed reduction to restore the bone alignment. Subsequent stabilization is then achieved with traction or external splinting by slings, splints, or casts. Braces are used to limit range of motion of a joint. External fixators provide fracture fixation based on the principle of splinting. There are three basic types of external fixators: standard uniplanar fixator, ring fixator, and hybrid fixator. The numerous devices used for internal fixation are roughly divided into a few major categories: wires, pins and screws, plates, and intramedullary nails or rods. Staples and clamps are also used occasionally for osteotomy or fracture fixation. Autogenous bone grafts, allografts, and bone graft substitutes are frequently used for the treatment of bone defects of various causes. For infected fractures as well as for treatment of bone infections, antibiotic beads are frequently used.
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BACKGROUND: Although clear differences in fracture site displacement have previously been demonstrated between transverse and oblique fracture models stabilised by an asymmetrical method, the direction of the obliquity has not been examined biomechanically. METHODS: Eight Sawbones tibiae were cut to represent oblique fractures: four ran from antero-inferior to postero-superior and four from antero-superior to postero-inferior. These were fixed with a Sheffield Ring Fixator and cyclically loaded in axial and off-axis compression. Direct measurements were taken of inter-fragmentary displacement. RESULTS: Significant differences were detected between the fracture directions (P < 0.01) and inter-fragmentary displacements were generally reduced in antero-superior to postero-inferior fractures compared with antero-inferio to postero-superior fractures. INTERPRETATION: Fixation asymmetries need to be tailored to specific fracture orientation to improve fracture site mechanics.
OBJECTIVE: Biodegradable materials are particularly useful for the fixation of zygomatic fractures. Different systems are commercially available. The aim of this study was to compare the clinical outcome of zygomatic fracture fixation using 3 biodegradable systems and a titanium osteosynthesis system. STUDY DESIGN: Patients with displaced fractures of the zygomatic bone presenting at our department from October 2001 to May 2003 were randomly allocated to 1 of 3 treatment groups for fracture fixation (study group A: LactoSorb: n = 18; study group B: BioSorb: n = 18; study group C: Delta: n = 18). Treatment outcome and complication rates were compared with a historic patient group with zygomatic fractures fixed with titanium osteosynthesis (control group D: n = 15). RESULTS: A total of 64 patients (study groups A + B + C: n = 49; control group D: n = 15) were followed for at least 24 months (range: 24 to 44 months). Forty-nine patients in the biodegradable study groups (group A: n = 15; group B: n = 17; group C: n = 17) who had their fractures fixed with biodegradable plates and screws alone or in combination with titanium plates and screws were reviewed postoperatively. Uneventful healing occurred during the entire follow-up period in 39 (80%) out of 49 patients in the biodegradable groups (A + B + C) and in 12 (80%) out of 15 patients in group D. Ten patients in groups A + B + C developed postoperative complications (infection: n = 3; soft tissue dehiscence: n = 2; implant-related tissue reactions: n = 5), compared with 3 patients in group D (soft tissue dehiscence: n = 1; unspecific pain: n = 2) (P = .97). Complications occurred in 4 patients in group A and 3 patients each in groups B and C. Smokers developed significantly more postoperative complications than nonsmokers in groups A + B + C (P = .01). CONCLUSION: There was no significant difference between biodegradable osteosynthesis materials or between biodegradable materials and titanium fixation with respect to fracture healing and postoperative complications. Postoperative complications were of a minor nature and resolved spontaneously or after local therapy. Smoking habits may play a significant role in the incidence of complications with biodegradable materials.