Clinical orthopaedics and related research
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Clin. Orthop. Relat. Res. · Oct 2004
Dose-responsiveness of electrophysiologic change in a new model of acute carpal tunnel syndrome.
This study was done to determine the dose-responsiveness during the development of acute pressure-induced median neuropathy in rabbits and to develop a new animal model of acute carpal tunnel syndrome. Twenty-three rabbits were used. Carpal tunnel syndrome was induced by infusing a controlled saline solution into the carpal tunnel of rabbits using a 21-gauge needle under general anesthesia to elevate the carpal tunnel pressure. ⋯ Complete conduction block occurred between 40 and 50 minutes at a pressure of 100 mm Hg. The degree of recovery after a conduction block was related inversely to the pressure-time integrals. Our animal model reflects the pathophysiology of acute carpal tunnel syndrome and shows a regular dose-responsiveness during the development of acute pressure-induced neuropathy.
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Clin. Orthop. Relat. Res. · Sep 2004
Case ReportsDorsal transscaphoid-transtriquetral perilunate dislocation in pseudarthrosis of the scaphoid.
A patient reported that he sustained a minor fall on the outstretched hand in hyperextension, pronation, and in ulnar deviation. Initial radiographs suggested dorsal transscaphoid-transtriquetral perilunate dislocation. Traditionally, however, this injury is the result of a high-energy impact. ⋯ Arthrography revealed intact lunotriquetral and scapholunate ligaments, precluding the possibility of preexisting ligamentous instability. Pseudarthrosis of the scaphoid with a loss of scaphoid function as a mechanical tie-rod of the carpus is most likely responsible for this complex injury. This is the first clinical study that shows that single scaphoid discontinuity without preexisting ligamentous carpal instability may lead to complex perilunar dislocation in minor trauma.
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Clin. Orthop. Relat. Res. · Sep 2004
Inferior vena cava filters prevent pulmonary emboli in patients with metastatic pathologic fractures of the lower extremity.
The records of 47 consecutive patients with metastatic pathologic fractures of the lower extremity were analyzed with respect to thromboembolic complications. All patients were unable to receive pharmacologic deep venous thrombosis prophylaxis, and were stratified into two groups, based on use of an inferior vena cava filter. Group I (n = 24) consisted of patients who had an inferior vena cava filter plus mechanical deep venous thrombosis prophylaxis (compression stockings and sequential compression boots); Group II (n = 23) consisted of a group of patients receiving only mechanical deep venous thrombosis prophylaxis. ⋯ The majority of venous thromboses (62.5%) were not detectable on duplex scanning, therefore were thought to arise from the pelvic venous system. Complications related to inferior vena cava filter insertion were minimal. For patients with metastatic pathologic fractures of the lower extremities who are unable to receive pharmacologic deep venous thrombosis prophylaxis, the use of inferior vena cava filters, in conjunction with standard mechanical deep venous thrombosis prophylaxis, is a procedure that has a low risk and is useful adjunct to prevent fatal pulmonary embolisms.
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Clin. Orthop. Relat. Res. · Aug 2004
ReviewSystemic pharmacologic postoperative pain management in the geriatric orthopaedic patient.
Although older adults have surgical procedures more frequently than any other group, they also experience the worst postoperative pain management. Among patients with orthopaedic disorders, this undertreatment of pain impacts postsurgical functional recovery and clinical outcomes. Recently adopted evidence-based pain management guidelines have improved care, but there still is significant room for improvement. We review standards for pain assessment in cognitively intact and impaired older adults, provide detailed guidelines for the pharmacologic treatment of postoperative pain in the orthopaedic geriatric patient, and review the stepwise approach to effective side-effect management in this population.
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Clin. Orthop. Relat. Res. · Aug 2004
ReviewBiomechanical considerations of fracture treatment and bone quality maintenance in elderly patients and patients with osteoporosis.
Osteoporosis is a major public health problem that is characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures of the hip, spine, and wrist. Poor bone quality in patients with osteoporosis presents the surgeon with difficult treatment decisions. Bone fracture repair has more pathways with combinations of bone formation mechanisms, which depend on the type of fracture fixation to be applied to achieve the desirable immobilization. ⋯ We describe the biomechanical considerations of osteoporosis and fracture treatment from various aspects. First, bone structure and strength characterization are discussed using a hierarchical approach, followed by an innovative knowledge-based approach for fracture reduction planning and execution, which particularly is beneficial to osteoporotic fracture. Finally, a brief review of the results of several experimental animal models under different fracture types, gap morphologic features, rigidity of fixation devices, subsequent loading conditions, and biophysical stimulation is given to elucidate adverse mechanical conditions associated with different bone immobilization techniques that can compromise normal bone fracture healing significantly.