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Intraoperative proximal femur fractures are a significant concern during noncemented total hip arthroplasty. The current study was performed to investigate the hypothesis that broaching the femur and inserting the stem without using mallet applied impact loads will reduce the risk of intraoperative fracture. Rosette strain gauges were applied to the medial and anteromedial cortex of six human anatomic specimen femurs to compare the strain distribution for broaching and stem insertion. Eight additional femurs were used to compare the strain distribution for stem insertion using impact loading and constant rate stem insertion. For the impact loading stem insertions, the soft tissues surrounding the femur were modeled. Constant rate stem insertions were performed using a mechanical testing machine. The largest strains measured at the medial and anteromedial sites primarily were aligned with the femur hoop axis. The largest strain magnitude, orientation, and sign (tensile or compressive) varied widely among femurs. The stem insertion strains were significantly larger than the broaching strains (two-way analysis of variance with replication). The impact stem insertion strains were not significantly different from the constant rate stem insertion strains. The results indicate that the femur geometry and material properties have a greater influence on the strain distribution than does the implantation technique.

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We studied the Medicare data from 1984 through 1987 for 687,850 fractures of the hip that had occurred in the United States. Our purpose was to determine the geographic, sex-specific, and age-interval variations in the relative risk of fracture of the hip in elderly white individuals. The rates of cervical, trochanteric, and subtrochanteric fracture, and the over-all rate of fracture at any of the three levels, increased with age, were greater for women than for men, and were higher in the Southern part of the country. However, there were regional, sex, and age variations. The ratio of cervical to trochanteric fractures was significantly higher in the East South Central region and lower in the Middle Atlantic and New England regions (p < 0.05). These were the same areas with the highest and lowest over-all rates, respectively, of fracture of the hip. The ratio of cervical to trochanteric fractures decreased from 1.52 in women who were sixty-five to sixty-nine years old to 0.81 in women who were at least eighty-five years old, but it stayed at approximately 1.00 for the corresponding age-groups of men. The ratio of fracture of the hip in women to fracture of the hip in men varied depending on the level of the fracture.

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Although significant gains in acquisition of a variety of skills following traumatic brain injury have been demonstrated, generalization of acquired skills presents a formidable challenge. Incidental teaching procedures refer to a sequence of interactions between a trainer and a learner which take advantage of teaching opportunities that arise naturally in unstructured situations and appear to be particularly applicable to communication deficits common to persons with traumatic brain injury. This paper presents an overview of incidental teaching procedures and a case study in which incidental teaching procedures were utilized in a multiple-baseline fashion across three sequential environments to increase complete requesting skills. Results show that complete requesting increased to nearly 100% of the trials in each new environment upon procedural implementation, compared to extremely low baseline levels. In addition, significant increases in independently initiated, rather than cued, requests occurred within the first few treatment sessions. Implications of incidental teaching procedures and case study results are discussed with suggestions for future research.

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Thirty shoulders, in 20 patients, which had undergone core decompression for symptomatic avascular necrosis of the humeral head were reviewed 2 to 14 years later (average 5.6). Twenty-two showed good or excellent clinical results; the other eight shoulders had required arthroplasty. All 14 shoulders with stage I or II radiological changes (Ficat and Arlet 1980) at operation had good or excellent results. We advocate early core decompression for symptomatic avascular necrosis of the humeral head.

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One hundred twenty-one consecutive nonrandomized primary total knee arthroplasties in 94 patients were performed between 1980 and 1984 using the Porous-Coated Anatomic prosthesis in patients with a diagnosis of severe rheumatoid arthritis. Of the 94 patients, 81 patients were able to be followed for more than 4 years, with the remaining 13 dying from unrelated causes prior to the 48-month follow-up. Of those arthroplasties with 48-month follow-up, 55 were uncemented and 26 were cemented. An 81% good to excellent result was seen for the cemented group and a 91% good to excellent result for the uncemented group. The postoperative arc of motion for the cemented group was 94 degrees, with the postoperative arc of motion in the uncemented group being 102 degrees. In evaluation of component interfaces, there were almost no lucencies seen among the femoral group, with no component failures in either group. Thirty-six percent of the uncemented group developed nonprogressive radiolucent lines along the tibial tray; 97% of these radiolucencies were less than 1 mm. Complications in the cemented group included a revision of one patellar and one tibial component for component loosening. In the uncemented group, complications included one case of deep sepsis following an intra-articular injection, loosening of two patellar components requiring revision, and loosening of two tibial components requiring revision.

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Individuals with mild to moderate mental retardation living in community residential settings (Experiment 1) or an institutional setting (Experiment 2) rated the acceptability of differential reinforcement and time-out applied to a mild and a severe behavior problem. Using analogue methodology similar to previous treatment acceptability studies (e.g., Miltenberger, Lennox, & Erfanian, 1989; Tarnowski, Rasnake, Mulicke, & Kelly, 1989), and a simplified rating scale developed for persons with mental retardation, community-based subjects rated differential reinforcement as more acceptable than time-out for the mild problem, whereas institutionalized subjects rated time-out as more acceptable than differential reinforcement when applied to the severe problem. These results were discussed and future research suggested.

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Since 1983, 19 patients have had bone grafting of acetabular defects in association with a porous-coated acetabular prosthesis. The defects were defined by anatomic location to assess the rates of incorporation at different sites. The average time to incorporation was 12 months, judged by trabecular continuity. Superolateral grafts showed a greater degree of rarefaction than medial grafts. Nonprogressive migration of the graft was seen in only two cases before full incorporation of the graft. Developing lucency was seen up to 2 mm at the prosthesis-graft interface but not at the graft-ilium level. Roentgenograms suggested that integration of porous acetabular prostheses into bone may improve results of reconstructive surgery of the acetabulum.

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Experience with total knee arthroplasty in the extremely elderly population, which has not been previously reported, is reviewed. Sixty-two total knee prostheses were implanted in 43 patients aged 80 to 95 years (average, 82 years). Ninety percent of the patients had a preoperative diagnosis of osteoarthritis. The results were compared with those obtained in a younger reference group (average age, 62 years) receiving 60 total knee prostheses.

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Once roentgenographic changes are apparent, osteonecrosis of the femoral head in the adult generally progresses to osteoarthritis within two to three years. A variety of conservative surgical procedures have been devised to conserve the femoral head with varying success. This study examines the effectiveness of pulsing electromagnetic fields and core decompression in the treatment of osteonecrosis of the femoral head. Both techniques reduce the incidence of clinical and roentgenographic progression. Exposure to pulsing electromagnetic fields appears to be more effective in hips with Ficat II lesions than in hips with more advanced lesions.

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The acceptability of four behavior modification procedures to direct-care and supervisory staff members of community-based (Experiment 1) and institutional (Experiment 2) facilities for persons with mental retardation was evaluated. Using the Treatment Evaluation Inventory (Kazdin, 1980a), staff members rated differential reinforcement of other behavior (DRO), time-out, overcorrection, and contingent shock, each applied to a mild and a severe behavior problem. Results from both experiments showed that treatments were rated according to their restrictiveness; DRO was most acceptable, followed by time-out, overcorrection, and shock. There was also a problem by treatment interaction in each experiment. No differences were found between the ratings of direct-care and supervisory staff members in either study. Results were discussed in relation to previous treatment acceptability research.

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The authors reviewed seven cases of proximal femur fractures with ipsilateral total hip arthroplasty between April 1985 and July 1987. All patients had ORIF with Odgen plates and Parham bands. Early mobilization of the patients avoided prolonged bedrest with its inherent morbidity. The morbidity of a revision of the total hip arthroplasty was also avoided. There were no problems with healing of the fractures sites and no evidence of devascularization related to Parham band utilization. All seven type A fractures went to clinical and radiographic union by 4 months and all seven were asymptomatic. The authors recommend the use of Ogden plates and Parham bands for type A fractures. Their clinical data suggest that this method is an effective treatment modality that produces a decrease in morbidity with satisfactory results.

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Nine patients with septic total knee arthroplasties (TKA) were treated between 1980 and 1984; six were gram-positive infections and three were gram-negative. Initial treatment included the maintenance of all solidly fixed components. Patients with loose components were treated with removal of all prosthetic material and subsequent reimplantation after a six-week course of antibiotics. At follow-up examination six of nine patients had satisfactory results. One patient maintained his original femoral and tibial components and one patient required a knee fusion to treat his recurrent gram-negative infection. Overall, complications were associated with chronic infection, gram-negative infection, and abnormalities of the extensor mechanism.

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This report describes mortality patterns as observed by death certification for the city of Port-of-Spain for 1 year. Diabetes mellitus and malignant neoplasms were the leading certified causes of death. (AU)

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Human synovium obtained at arthroplasty from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) were characterized by assessing mast cell morphology, content and function. Histological studies confirmed significant numbers of mast cells in both RA and OA synovium. Electron microscopic data support the morphologic similarity between human synovial mast cells and human mast cells in lung and intestine. Likewise, synovial mast cells do not appear to be functionally different from pulmonary or intestinal mucosal mast cells. Mast cell suspensions with a cellular histamine content of 4.3 +/- 0.5 pg/cell (mean +/- SEM) released histamine following provocation with anti-IgE and calcium ionophore but not compound 48/80, f-met peptide or bradykinin. Prostaglandin D2 (PGD2) and leukotriene C4 (LTC4) were also released in response to anti-IgE. Auranofin inhibited anti-IgE provoked histamine, PGD2 and LTC4 release while gold sodium thiomalate, cromolyn and indomethacin had no effect on histamine release. Theophylline inhibited anti-IgE induced histamine release only at concentrations greater than or equal to 10(-3) M. Our study argues against functional or morphologic mast cell heterogeneity of human intestinal, lung and synovial origin and suggests that mast cells may have a pathogenic role in both RA and OA.

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The literature from 1981 through 1985 in seven major journals on the treatment of behavior problems in persons with mental retardation was reviewed. We included all studies designed to decrease a target behavior that included formal pre- and posttreatment data. Behavior problems were categorized into seven classes. Treatment procedures were grouped into three levels by degree of restrictiveness according to the model proposed by Brazier and MacDonald (1981). We reported the problems treated with various procedures and the frequencies and effectiveness values for all the problem--procedure combinations. Differential reinforcement and overcorrection were the two most widely used procedures. We drew conclusions about treatment of specific classes of problem behaviors based on the results of this review.

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Patterns of malposition of total knee femoral components are presented and are correlated to specific faulty bone cuts. Femoral component malposition pattern recognition will facilitate intraoperative correction of inaccurate bone cuts.

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The effects of polymethylmethacrylate (PMMA) exposure upon macrophage viability and function were studied in an attempt to determine what role these cells play in the loosening of cemented arthroplasties. P388D1 murine macrophage cell line was exposed to PMMA and polystyrene particles of similar size and concentration. DNA synthesis following exposure to PMMA or polystyrene was studied by [3H]thymidine incorporation. Macrophage function was studied by analyzing the ability of activated macrophages to kill mast cell targets following particle exposure. Our results demonstrate that exposure of macrophages to PMMA particles in vitro inhibits DNA synthesis and impairs their cytotoxic ability. Histologic examination revealed that macrophages phagocytose both PMMA and styrene particles, but the former eventually lyse these cells. Our studies suggest that the histologic appearance of macrophages and foreign body giant cells at the bone-cement interface may be secondary to a repetitive cycle of PMMA particle phagocytosis and cell death, similar to that found in a foreign body granulomatous response.

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