الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
In Egypt, millions of people are affected by osteoporosis. Osteoporosis is the leading cause of fractures in the elderly. Women aged 50 years have a 40% lifetime fracture rate due to osteoporosis. Osteoporosis is associated with 80% of all the fractures in people aged above 50 years 63, 64.
Achieving stable fixation in the presence of diminished bone quality represents a substantial challenge. In fact, some surgeons consider it risky to choose operative treatment in older patients with fractures. On the other hand, an unstable, non-united fracture can be extremely disabling and painful. Because of the decreased holding power of plate-and-screw fixation in osteoporotic bone fractures, internal fixation can have a high failure rate, ranging from 10% to 25% 2.
Other important issue is the osteoporotic fractures in elder peoples - due to osteoporosis of bones - form one of the major problems among any population especially with increasing their percentage in any population. Fixation of fractures of osteoporotic bones by conventional plates DCP starts to be inconvincible to many orthopedic surgeons due to weakness of fixation by conventional screws in the weak osteoporotic cortices of bone making it important to increase the number of fixating screws leading to making long surgical wound with increasing blood loss increasing the risk of operation in an old age patient 14.
In osteoporotic bone, locking head screws have better resistance against bending and torsion forces with less pull out of the screw. The locked screws do not compress the plate to the bone, so the plate / bone interface is not loaded along the screw axis, which reduces the tendency to strip the thread in the bone. Fixed angle devices are not subject to the toggling (windshield wiper effect) seen with unlocked screws, which improves fixation in osteoporotic bone 15.
A major change in the rationale of fracture fixation occurred with development of locked bridging internal fixation like the PC-Fix. When using this implant and the theory of “bridging plate osteosynthesis,” fracture union occurred by secondary, not primary, bone healing as with rigid internal fixation. This initial locked plate design created the first screw-plate single composite beam construct, much like a conventional external fixator. Further refinements to the PC-Fix concept led to the design and manufacture of the LCP 142.
Locked plates may prove to be ideal for: 1) indirect fracture reduction, as they can tolerate imperfect reduction and need not be placed on the tension side of the bone; 2) diaphyseal/metaphyseal fractures in osteoporotic bone; 3) the bridging of severely comminuted fractures to minimize soft tissue damage; and 4) the plating of fractures where, due to anatomic constraints, a conventional plate may not be placed on the tension side of the fracture 13.
In our search we found many studies provided satisfactory results regarding the use of LCP. The first clinical results of the LCP were studied by Sommer and collaegues 17. They concluded that the new system of LCP can be regarded as technically mature. It offers numerous fixation possibilities and has proven its worth in complex fractures situations and in revision operations after the failure of other implants.
An Egyptian study was performed by Abdel-Alla and his colleagues 146, on the use of a locked plate in the treatment of non-united femoral shaft fractures. They concluded that locked plate fixation is rigid enough for bone healing and to allow early postoperative mobilization, with good functional outcome.
Korner and coworkers 147 assessed the biological, biomechanical and surgical aspects of the LCP-concept in the operative treatment of distal humerus fractures. On the basis of clinical and biomechanical experiences, the authors consider LCP a helpful tool for increasing primary stability in osteosynthesis of distal humerus fractures. LCP might be of substantial advantage in patients with diminished bone mineral quality or in the presence of metaphyseal comminution.
Stability of locking compression plates in osteoporotic bone was assessed by Gardner and his colleagues 148. They found that the use of LCP produce more stable construct when compared with the standard LC-DCP in the torsional loading direction, when tested in an osteoporotic diaphyseal radius unstable fracture model. Locked plates eliminate both screw toggle and plate-bone friction. This could be particularly useful in osteoporotic bone, where screw purchase may be suboptimal, and in comminuted fractures that are inherently unstable.
In a study performed by Infanger and his colleagues 151 they examined the use of LCP in fixation of displaced intraarticular fractures of the distal radius. They concluded that LCP technique offers several advantages, even in elderly patients with osteopenic bone, including rigid plate fixation, allowing for early functional treatment without a cast. Bone grafting, with its significant morbidity, is not necessary, even in distal radius fractures with dorsal comminution.
Fulkerson and his colleagues 152 performed a comparison between locked and conventional plating techniques. They compared the stability of various plating with locked screw constructs to conventional non-locked screws for fixation of a comminuted diaphyseal fracture model using a uniform, synthetic ulna. Their results supported the use of plating with bicortical locked screws as an alternative to conventional plating for comminuted diaphyseal fractures in osteoporotic bone. Bicortical locked screws with minimal displacement from the bone surface provide the most stable construct in the tested synthetic comminuted diaphyseal fracture model.
Gardner and his colleagues 157 examined the hybrid locked construct against the conventional unlocked construct in unstable osteoporotic fracture model of the humerus. They found that the unlocked constructs were significantly less stiff than the locked hybrid constructs (p<0.001). They concluded that locked hybrid plating is significantly more stable than unlocked constructs under torsional cyclic loading.
After this systematic review, it was concluded that locked plates may increasingly be indicated for indirect fracture reduction, diaphyseal/metaphyseal fractures in osteoporotic bone, bridging severely comminuted fractures, and the plating of fractures where anatomical constraints prevent plating on the tension side of the bone.