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The enormous interest in CT scanning appears fully justified as this remarkable technique continues its development. In orthopedics, it has a variety of roles to play: in trauma, tumor management, and developmental disorders. As experience with the CT scan in musculoskeletal disease is accumulated, new applications will undoubtedly become apparent, adding to the already impressive list.
Mesenchymal neoplasia includes an extensive variety of tumors. It is important that the primary care physician understand the different qualities of benign and malignant processes in incidence, pathogenesis, history, physical findings, and diagnostic work-up and, as a result, be able to make the appropriate orthopedic consultation when necessary. It also is important that they understand basic concepts of definitive treatment so that they may educate their patients. Table 2 lists some of the more common benign and malignant soft-tissue tumors. It is by no means an attempt to be inclusive, but rather to serve as an introduction to a vast group of neoplasms.
The purpose of this study was to investigate in vitro the apoptosis- and/or necrosis-inducing potential of polymethylmethacrylate (PMMA)-based bone cements for prosthetic surgery. Four bone cements widely used in orthopedics were tested as extracts onto osteoblast-like MG-63 cells and for comparison, HL-60 cells, which are remarkably sensitive to apoptotic stimuli. Neutral red uptake (NRU) was used to measure cell viability while Hoechst 33258 staining was used to detect DNA content. Apoptosis was characterized using a BrdU-based ELISA assay for DNA fragmentation and examined by fluorescence microscopy using acridine orange and propidium iodide staining of nuclei. The generation of reactive oxygen species (ROS), which could mediate apoptosis, was verified using dichlorofluorescein-diacetate (DCFH-DA) oxidation to DCF. After 24 h of challenge of the cells with the four cement extracts, the viability of either MG-63 or HL-60 cells was found to be unaltered, as recorded by NRU. Apoptotic cell death was induced by three cements in HL-60, whereas MG-63 cells were significantly affected by the four cements tested: the finding of DNA fragments both in the cytoplasm and supernatants of MG-63 after 24 h demonstrated that these cells underwent late-apoptosis secondary necrosis. Fluorescent staining of the nuclei confirmed the results obtained with the ELISA test. Oxygen free radicals were elicited by two cements in HL-60 cells, while MG-63 did not generate ROS in response to cements. This study helps to gain more insight into the mechanism of cell death induced by PMMA-based cements and suggests apoptosis of osteoblasts as a part of the tissue reaction around cemented prostheses.
This paper provides a general regulatory background of acrylic bone cements, chemical composition information on several commercially available bone cements, physical and chemical methods of analyses, mechanical test methods, and risks and failure mechanisms of acrylic bone cements. Suggestions and recommendations presented in Tables 2 and 3 are not mandatory requirements but reflect data and methodologies which the FDA's Orthopedic Devices Branch (ORDB) believes to be acceptable to evaluate most pre-clinical data. FDA may require information in addition to that contained in this paper. In some instances, a sponsor may be able to sufficiently justify the omission of some tests. Although this paper describes certain administrative requirements, it does not take the place of the requirements contained in Title 21 of the Code of Federal Regulations (21 CFR) Parts 801, 807, 812, and 814 or those found in the statute.
A technique is presented for rapid evaluation of the extent of orthopedic or neurologic injury. Consistent use of the method, a combination of active motion against resistance and standard neurologic tests, has helped avoid unnecessary radiation and costs while correlating well with physical and radiographic findings in the awake, cooperative, injured individual.
Orthopedic injuries in children are unique in terms of the mechanisms of injury, pathophysiology, and healing. This article reviews the pediatric fracture patterns and common pediatric injuries or complaints seen in the emergency department, with an emphasis on management in the emergency department. Additionally, the approach to pediatric cervical spine injuries and child abuse will be described as it pertains to the emergency physician.
There is increasing demand on equine practitioners to provide confirmation of their diagnoses. For obscure lameness and for many of the more difficult locomotory problems presented in referral hospitals, the question to be answered is not only how to make the most accurate diagnosis but also how to document the findings so that there is less doubt in the mind of the client. This article describes a quasi algorithmic approach to choosing the best combinations of the increasingly sophisticated imaging methods available for evaluation of orthopedic disease.
This article attempts to address what the authors consider to be the major orthopedic problems in the racehorse, with particular attention to their treatment and prognosis. These problems include fractures, osteochondral fragments, synovitis, degenerative joint disease, tendinitis, desmitis, osteochondritis dissecans, and subchondral cystic lesions of the joints.
Orthopedic biomaterials are foreign bodies and the molecular architecture of their surfaces provides a point of attachment for bacteria. This adherence is made possible through the interaction of the protein interface and the bacterial adhesins. Bacterial colonies use slime and biofilm as means of protection. The development of bacteria towards a reversible state of stationary growth or microcolony variants permits their survival. Microparticles released by biomaterials cause the chronic inflammation associated with the aseptic loosening of prostheses. Some bacterial sub-populations develop transitory resistance to bactericidal antibiotics in the presence of these materials.
Stress distribution in the temporomandibular joint (TMJ) during chincup therapy was investigated by means of a three-dimensional finite element model of the mandible, including the TMJ. An orthopedic chincup force of 400 gf (3.92 N) was applied at the pogonion of the mandible in the directions ranging from -50 degrees to 40 degrees, relative to the line connecting the pogonion and condyle. Compressive stresses, widely distributed on the condyle and glenoid fossa and in the articular disk, were larger in the posterior area than in the anterior and middle regions, when the force direction was from -50 degrees to 0 degree, whereas the forces applied in the remaining directions produced relatively uniform stress distributions. An interesting finding was that tensile stresses were induced in the anterior region of the articular disk, irrespective of force direction, although the remaining areas experienced compressive stresses. It is shown that changes in stresses in the TMJ are highly pertinent to the direction of chincup forces. When the directional angle was around -50 degrees, the variation in stresses in the TMJ was greatest. As the angle was changed to 30 degrees or 40 degrees, the stresses approached a certain level of compressive stress, which indicated the force direction as an optimal application of orothopedic chincup force in terms of biomechanically balanced stress distribution for the TMJ components.
The orthodontic and orthopedic effects of the Activator, Activator-Headgear Combination (ACHG) and the Bass appliance systems were compared by analyzing the cephalometric records of 64 subjects, who were treated for skeletal Class II malocclusion, with both conventional and Pancherz's methods. Differences between observations on the different occasions (starting and ending values) were tested with Wilcoxon's matched pairs rank test. Kruskal-Wallis nonparametric analysis of variance was carried out in different situations among all three groups. If a level of significance less than 0.05 was observed, Scheffè's method of multiple comparisons was used to determine differences among groups. The results of this study showed that greater improvement in sagittal skeletal relationship (ANB angle) was obtained in both Bass and ACHG groups than in the Activator group. The differences between the groups were most pronounced for dental variables. The Bass appliance was found to be more effective in the control of the unwanted side effects (proclination of lower incisors, retroclination of upper incisors). Unfavorable labial tipping of the lower incisors was also prevented with the ACHG appliance.
The goals in the management of septic arthritis are joint decompression, joint sterilization, and preservation of joint function. Opinions on how these goals are best accomplished vary among medical disciplines. Although the literature supports both serial aspirations and arthrotomy as viable ways to treat pyarthrosis, most orthopedic surgeons prefer arthrotomy. There are advantages to surgical management, including more complete decompression, especially in infections characterized by thick, purulent fluid or loculations; a lower intra-articular bacterial count after lavage; the opportunity to perform a synovectomy; and no delay in cases that may be unresponsive to simple aspiration and antibiotics. Rehabilitation of the septic joint is paramount in preserving range-of-motion and cartilage protection. Although splinting and immobilization are necessary in treating acute infections, early range of motion is paramount in preserving long-term joint function.
The changes that occur in the body as part of the normal aging process and the degenerative changes that often accompany them predispose the elderly to various orthopedic problems. Age, general health, and functional level are all important factors in determining the optimum management of these patients. Treatments are aimed at restoring patient independence and activity to preinjury levels, while at the same time minimizing the risks of treatment complications.
STUDY OBJECTIVE: To compare the onset time and duration of epidural anesthesia, and the quality of postoperative analgesia produced by levobupivacaine, racemic bupivacaine, and ropivacaine. DESIGN: Prospective, randomized, double-blinded study. SETTING: Inpatient anesthesia at a University Hospital. PATIENTS: 45 ASA physical status I, II, and III patients, undergoing elective total hip replacement. INTERVENTIONS: After standard intravenous midazolam premedication and infusion of 500 mL of Ringer's acetate solution, patients were randomly allocated to receive epidural block with 0.5% levobupivacaine (n = 15), 0.5% bupivacaine (n = 15), or 0.5% ropivacaine (n = 15). Postoperatively, after pinprick sensation recovered at T(t), a patient-controlled epidural infusion was provided with 0.125% levobupivacaine, 0.125% bupivacaine, or 0.2% ropivacaine, respectively (baseline infusion rate 5 mL/hr; incremental bolus 2 mL, lockout time: 20 min). Intravenous ketoprofen was also available for rescue analgesia if required. MEASUREMENTS AND MAIN RESULTS: The onset time of sensory block was 31 +/- 16 minutes with levobupivacaine, 25 +/- 19 minutes with bupivacaine, and 30 +/- 24 minutes with ropivacaine (p = 0.98), after a median (range) volume of 15 (10-18) mL in Group Levobupivacaine, 14 (10-18) mL in Group Bupivacaine, and 15 (10-18) mL in Group Ropivacaine (p = 0.85). Six patients in the ropivacaine group (40%) showed an intraoperative Bromage score <2 as compared with only three patients of Group Levobupivacaine (20%) and no patient of Group Bupivacaine (p = 0.02). Recovery of pinprick sensation at T(t) occurred after 214 +/- 61 minutes with levobupivacaine, 213 +/- 53 minutes with bupivacaine, and 233 +/- 34 minutes with ropivacaine (p = 0.26). A similar degree of pain relief was observed in the three groups without differences in local anesthetic consumption and need for rescue analgesia. Motor blockade progressively resolved without differences among the three groups. CONCLUSIONS: Levobupivacaine 0.5% produces an epidural block of similar onset, quality, and duration as the one produced by the same volume of 0.5% bupivacaine, with a motor block deeper than that produced by 0.5% ropivacaine. When prolonging the block for the first 12 hours after surgery with a patient-controlled epidural infusion, 0.125% levobupivacaine provides adequate pain relief after major orthopedic surgery, with similar recovery of motor function as compared with 0.125% bupivacaine and 0.2% ropivacaine.
STUDY OBJECTIVES: To investigate the changes in plasma atrial natriuretic peptide, renin activity, and aldosterone during isoflurane anesthesia in patients over 80 years. DESIGN: Prospective, randomized, controlled study. SETTING: Operating rooms and postanesthesia recovery room of Hirosaki University Hospital and Hakodate Watanabe Hospital. PATIENTS: 36 patients undergoing reduction of femur neck fracture (18 patients ranging in age from 80 to 99 years and 18 patients ranging in age from 40 to 59 years as control). INTERVENTION: In all patients, anesthesia was induced with intravenous (i.v.) thiopental sodium 3 to 5 mg/kg succinylcholine 0.5 to 1.0 mg/kg for facilitating tracheal intubation and was maintained with 1.2% to 2.0% isoflurane in 50% oxygen. MEASUREMENTS AND MAIN RESULTS: Plasma atrial natriuretic peptide (ANP), plasma renin activity (PRA), and plasma aldosterone (PA) levels were assayed. Blood samples were obtained on the following occasions: before the induction of anesthesia, 15 minutes after skin incision, 90 minutes after anesthesia induction, and the 60 minutes after the end of surgery. Plasma renin activity and PA levels in patients from 40 to 59 years increased significantly 90 minutes after induction, whereas PRA and PA levels in patients over 80 years were unchanged. There were significant differences in PRA and PA levels between both groups at any time of measurements. Plasma ANP levels of patients over 80 years were significantly elevated at 90 minutes induction. Plasma ANP levels in patients over 80 years at 90 minutes after the induction and 60 minutes after the end of surgery were significantly higher than those of patients from 40 to 59 years. Plasma renin activity in hypertensive patients over 80 years at 90 minutes after the induction was significantly lower than that observed in normotensive patients. The renal loss of sodium was increased in the hypertensive patients. CONCLUSIONS: Orthopedic patients over 80 years of age have decreased PRA and PA, increased ANP, and renal loss of sodium as compared with patients 40 to 59 years, during isoflurane anesthesia. Plasma renin activity at 90 minutes after induction was decreased in hypertensive patients over 80 years, but PA and ANP were not affected by hypertension during anesthesia.
The differences in the response of patients to the same orthodontic treatment are, to a great extent, the result of variability in the direction and rate of craniofacial growth. Furthermore, there is currently little scientific evidence that the temporary improvement of skeletal relationships from orthopedic appliances will alter the craniofacial skeleton on a permanent basis. However, contemporary literature is beginning to show that certain appliances may be more effective than others at a specific point in the growth process. Timing of treatment in a patient is becoming of increased clinical importance. A review of the anatomy of palatal expansion indicates that expansion is much greater in the anterior portion of the palate, in both horizontal and vertical planes. Assessment of skeletal maturity for treatment timing and growth prediction is most commonly performed with the hand/wrist radiograph. A new method is presented which uses epiphyseal and diaphyseal widths and fusion of selected phalanges to determine the relative position of the individual on the pubertal growth curve. Skeletal maturity assessment is a traditional attempt to judge physiological development. The future of craniofacial growth assessment lies in the development of physiological measurements which are both replicable and valid and clinically feasible. The data from these studies provides information to allow better quantitative diagnosis and treatment as well as objective assessment of the treatment outcome.
Distraction osteogenesis is a surgical-orthopedic method for lengthening bone by separating or distracting a fracture callus. This technique has a long history in limb lengthening and has recently been used to lengthen mandibles and maxillae in human patients. Distraction osteogenesis represents a powerful method of producing unlimited quantities of living bone which can be formed along any plane of space. Because this method uses local host tissue, it offers many advantages over bone grafting. In the author's experience, large (10-22 mm) antero-posterior and vertical corrections of mandibles can be achieved using this technique. The purpose of this article is to review its biological basis and discuss recent clinical applications. This article reviews the history, theory, current management, and limitations of distraction osteogenesis in treating craniofacial anomalies.
Radiographic examination of exotic animal species provides significant diagnostic information to the practitioner so long as attention is paid to positioning and radiographic detail and if variations in normal radiographic anatomy are contemplated. Fracture of pneumatic bones (humerus or femur) in avian patients often results in subcutaneous emphysema, much like an open fracture. If fracture alignment is anatomical, there is generally little callous formation visible in avian and reptile patients; however, if malunion occurs, then certainly callous can be visualized. Aggressive or excessive periosteal proliferation in exotic species often predicts osteomyelitis. Practitioners can increase their diagnostic capabilities and thereby decrease any preconceived anxiety by applying the same general interpretive concepts used in the radiography of more routine small animal patients and by evaluating the resultant radiographs in a systematic manner. With the exception of certain anatomical differences and alterations in response to injury, exotic animal species suffer the same types of orthopedic disease do dogs and cats.