Ligament balancing in computer-assisted total knee arthroplasty: improved clinical results with a spring-loaded tensioning device.

Total knee arthroplasty (TKA) remains one of the most successful procedures in orthopaedic surgery. Complications certainly exist and are often related to failure of knee ligament balance. This asymmetry subsequently leads to component mal-alignment and loosening often secondary to deviation of the lower extremity mechanical axis. Understanding knee mechanics is essential, and recent technological advances have begun to minimize postoperative problems. A tensioning device that respects the native patellofemoral anatomy as well as the natural ligamentous strains has been developed. The surgical integration of computer-assisted navigation has allowed for enhanced accuracy and subsequently better results. The purpose of the current paper is to discuss the evolution of an improved ligament tensioning device, in the setting of classic mechanical guidance versus computer assistance and its postoperative impact on total knee outcomes in terms of manipulation rates and two-year radiographic alignment data. Based on a single surgeon series, mechanically guided arthroplasties resulted in a 16 per cent manipulation rate. Computer assistance with spacer blocks decreased the manipulation rate to 14 per cent, while using a novel tensioner device further decreased the manipulation rate to 7 per cent, a significant difference of p < 0.01. Radiographic data illustrate all TKAs with the tensioner to be within 4 degrees of the desired position.

A self-management program for adult asthma. Part I: Development and evaluation.

BACKGROUND: We developed and evaluated a self-management program for adult asthma. In developing the program, we considered questions of format and behavior control. The format we selected included components known to be effective in educational settings. We regulated asthma management behavior through the introduction of environmental cues. METHODS: Seventy-six subjects, whose asthma was generally under medical control, were assigned randomly to either a treatment group or a waiting-list control group. Those in the treatment group were exposed to a 7-week program that incorporated proven features of providing effective training and establishing behavioral control. Subsequently, subjects in the control group received the treatment. Short-term evaluation of the treatment was made after the subjects in the experimental group were trained but before the control subjects were trained. Long-term evaluation was conducted after both groups of subjects were trained. RESULTS: Over the short term, self-management training led to fewer asthma symptoms and physician visits and improvement in asthma management skills and cognitive abilities. Over the long term, self-management training was related to lower asthma attack frequency, reduced medication use, improvement in cognitive measures, and increased use of self-management skills. CONCLUSIONS: The program improved asthma management in patients whose conditions were already under good medical control. The effects of the program were apparent a year after the conclusion of self-management training.

Evaluation and treatment of localized vaginal immunoglobulin E-mediated hypersensitivity to human seminal plasma.

BACKGROUND: Localized vaginal inflammation after contact with seminal plasma has been previously described but without a clear understanding of the underlying immunopathogenesis. The purpose of this report is to describe three women who presented with localized postcoital vaginal reactions that were successfully treated with rapid immunotherapy using human seminal plasma proteins. CASES: One atopic and two nonatopic women with histories of immediate onset of localized postcoital vaginal symptoms and immediate skin test reactions to human seminal plasma were treated with rapid immunotherapy using their spouse's purified seminal plasma protein fractions. One of the women had decreased cutaneous reactivity post-therapy and detectable circulating specific immunoglobulin (Ig) G and IgE antibodies to her spouse's fractionated seminal plasma proteins. Increased IgG, IgE, and IgA antibodies were found in these patients' sera to whole seminal plasma of a normal male control and to fractionated proteins of different men, indicating that one or more homologous seminal plasma proteins may be responsible for these reactions. Their localized vaginal symptoms resolved completely after rapid immunotherapy treatment. Two of the women have remained symptom-free, whereas the third woman had recurrent localized vaginal symptoms after failing to maintain frequent sexual intercourse after treatment. CONCLUSIONS: Rapid immunotherapy immediately alleviated vaginal reactions to seminal plasma in all patients. These cases indicate that the pathogenesis of some localized vaginal inflammatory reactions may involve IgE-mediated or other immune responses to human seminal plasma proteins.

The low prevalence of occupational asthma and antibody-dependent sensitization to diphenylmethane diisocyanate in a plant engineered for minimal exposure to diisocyanates.

BACKGROUND: Diisocyanate chemicals are leading causes of occupational asthma (OA). METHODS: We conducted a cross-sectional study of 243 workers exposed to diphenylmethane diisocyanate (MDI) in a urethane mold plant that had been designed to minimize MDI exposure (levels were maintained below 0.005 ppm and were continuously monitored). All participants were screened by questionnaire and tests for serum antibodies to MDI-human serum albumin (HSA). On the basis of questionnaire responses, diagnoses were derived that included OA; non-OA; work-related and non-work-related rhinitis; and lower respiratory irritant responses. Serial peak expiratory flow rate studies were performed for 2 weeks in 43 workers with and in 23 workers without lower respiratory symptoms. RESULTS: Results of serial peak expiratory flow rate studies were abnormal in 3 (33%) of 9 workers with OA, in 2 (50%) of 4 with non-OA, and in 2 (9%) of 23 case control subjects. A significant association was found between peak flow rate variability and a questionnaire asthma diagnosis (chi 2 p < 0.002). Physicians confirmed three cases of OA, one of which occurred in a control worker who was free of symptoms. In all three cases asthma symptoms remitted after the worker left the workplace. Serum specific IgE and IgG levels were elevated in 2 of 243 workers, one of whom was prick test positive to MDI-HSA and had had cutaneous anaphylaxis after MDI exposure. CONCLUSIONS: On the basis of these cases, specific work activities associated with exposure to MDI were identified and corrective measures were instituted. Strict control and monitoring of ambient MDI exposure was associated with a low prevalence of specific sensitization to MDI and a lower than expected prevalence of OA.

Selective desensitization to seminal plasma protein fractions after immunotherapy for postcoital anaphylaxis.

A 24-year-old white woman reported sexual intercourse-related pruritus, hives, wheezing, and dyspnea within 5 minutes after ejaculation. Systemic reactions (SRs) were prevented by use of condoms. Prick testing confirmed sensitization to five Sephadex G-100-separated fractions of her husband's seminal plasma. The intradermal end point threshold concentrations (ETC) were 10(-4) and 10(-1) micrograms of protein per milliliter to fractions 2 and 3, respectively. Leukocyte histamine release studies exhibited 100% release to fraction 2 and 37% release to fraction 3. A 2-day protocol of rapid immunotherapy (IT) was performed with subcutaneous incremental doses of human seminal plasma (HuSePl) fractions 2 and 3. The patient experienced an SR after receiving a cumulative dose of 38.55 micrograms of fraction 2 on day 1. On day 2, rapid IT with fraction 2 was administered until the patient experienced a mild SR after having received a cumulative dose of 102.8 micrograms. There was a one-log10 increase in the intradermal ETC to both fractions 2 and 3 at the end of day 2. IT was continued three times weekly for 4 months until the patient tolerated 100 micrograms doses of both fractions 2 and 3. At 4 months, coitus was resumed without SRs, and HuSePl IT was stopped. The intradermal ETC to fractions 1, 3, 4, and 5 was increased 6 months after cessation of HuSePl injections, but there was a one-log decrease in the ETC to fraction 2. Our experience demonstrated that systemic tolerance can be achieved by parenteral administration of selected HuSePl fractions. Partial immunologic desensitization of patients with anaphylactic sensitivity can be achieved.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical and immunologic studies of rapid venom immunotherapy in Hymenoptera-sensitive patients.

A 2- to 5-hour regimen of rapid venom immunotherapy (RVIT) was administered to 33 patients with anaphylactic sensitivity to Hymenoptera venom in a hospital setting in which full emergency resuscitation equipment was available. The RVIT was administered as 10 increasing doses of each treatment venom every 10 to 15 minutes to achieve a final dose on day 1 of 58.55 micrograms per venom. Patients returned for booster venom injections of 60 micrograms on day 3, 70 micrograms on day 7, 80 micrograms on day 21, and 100 micrograms on day 35 after RVIT. Serial antigen-induced leukocyte histamine release studies were performed on day 1 in 10 patients before and after RVIT, as well as 3 1/2 months after initiation of RVIT. Of 33 patients, 32 achieved a cumulative venom dose on day 1 of at least 50 micrograms, and the entire group received a mean dose of 95.46 micrograms. Local reactions during RVIT occurred in 18 (55%) patients. Four patients (12%) experienced mild systemic reactions during or after completion of RVIT. Subsequent booster venom doses administered to 29 patients were well tolerated. A decrease in venom-induced leukocyte-histamine release from baseline was detected in three (30%) patients immediately after RVIT and in seven (70%) patients months after achieving maintenance doses. Cutaneous sensitivity decreased by at least one log10 concentration in eight (32%) of 25 patients. Twenty-two natural re-sting events occurred in 12 (50%) of 24 patients surveyed after successful completion of RVIT, of whom seven identified the insect as one for which they had been treated. No systemic reactions were reported. Results of this study indicate that RVIT is a safe, alternative method of venom administration for patients who are at immediate risk for re-sting anaphylactic episodes.