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This study examines the potential cost savings for the health system and the community in a broadly accessible model through the increased utilization of unicompartmental knee arthroplasty (UKA) using robotic arm-assisted UKA (raUKA) versus conventional total knee arthroplasty (cTKA). We retrospectively reviewed 240 patients where the first 120 consecutive raUKA performed during this period were matched to 120 cTKAs. Clinical data from the medical records and costs for procedure for each component were collected. Bivariate analyses were performed on the data to determine if there were statistically significant differences by surgery type in clinical outcomes and financial costs. There was a significantly lower cost incurred for raUKA versus cTKA with an average saving of AU$7,179 per case. The operating time (86.0 vs. 75.9 minutes; p  = 0.004) was significantly higher for raUKA, but the length of stay was significantly lower (1.8 vs. 4.8 days; p  < 0.001). There was a significant difference in the use of opioids between raUKA and cTKA (125.0 morphine equivalent [ME] vs. 522.1 ME, p  < 0.001). This study demonstrated that the use of raUKA rather than cTKA in suitably indicated patients may realize significant cost savings., Competing Interests: None declared., (Thieme. All rights reserved.)

Background: Displaced femoral neck fractures (DFNF) are common and can be treated with osteosynthesis, hemiarthroplasty (HA), or total hip arthroplasty (THA). There is no consensus as to which intervention is superior in managing DFNF., Methods: Studies were identified through a systematic search of the MEDLINE database, EMBASE database, and Cochrane Controlled Trials. Included studies were randomized or controlled trials (1966 to August 2018) comparing THA with HA for the management of DFNF. (https://www.crd.york.ac.uk/PROSPERO Identifier: CRD42018110057)., Results: Seventeen studies were included totaling 1364 patients (660 THA and 704 HA). THA was found to be superior to HA in terms of risk of reoperation, Harris Hip Score and Quality of Life (Short Form 36). Overall, the risk of dislocation was greater in THA group than HA in the first 4 years, after which there was no difference. There was no difference between THA and HA in terms of mortality or infection., Conclusion: Overall, THA appears to be superior to HA. THA should be the recommended intervention for DFNF in patients with a life expectancy >4 years and in patients younger than 80 years. However, both HA and THA are reasonable interventions in patients older than 80 years and with shorter life expectancy., (Copyright © 2019. Published by Elsevier Inc.)

Background: Computer navigation and image-derived instrumentation (IDI) are technology-based methods developed to improve outcomes and potentially reduce revision total knee arthroplasty (TKA). IDI refers to the use of manufactured, patient-specific surgical jigs. Conflicting reports exist on IDI-associated improvements in outcomes. The primary aim of the current study was to compare the rates of revision among TKA cases in which components were initially implanted with use of IDI, computer navigation, or neither of these methods ("other" TKA). The secondary aim was to determine whether the outcomes of IDI differed for specific subgroups., Methods: Data were obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) for the 3 TKA groups: IDI, computer-navigated, and other TKA. The study period was from the first IDI procedure recorded by the AOANJRR (April 2010) to December 31, 2016. The analysis was restricted to primary TKA cases undertaken for osteoarthritis and involving patellar resurfacing and the use of a cross-linked polyethylene insert. Subanalyses were performed to evaluate the effects of age, sex, implantation method, IDI manufacturer, prosthetic design, and prosthesis type on the rates of revision. Kaplan-Meier estimates of survivorship described the time to first revision. Hazard ratios (HRs, Cox proportional hazards models) with adjustment for age and sex were used to compare revision rates., Results: IDI was used in 5,486 primary TKA procedures. There was no significant difference among the groups in the cumulative percent revision (CPR) at 5 years: 3.3% (95% confidence interval [CI], 2.4% to 4.6%) for IDI, 2.4% (95% CI, 2.2% to 2.7%) for the computer-navigated group, and 2.5% (95% CI, 2.3% to 2.7%) for other TKA. Posterior-stabilized TKA with use of the IDI method had a significantly higher rate of revision at >3 months (HR, 1.45 [95% CI, 1.02 to 2.04]; p = 0.036), as did IDI TKA in the ≤65-year-old patient cohort (HR, 1.52 [95% CI, 1.10 to 2.09]; p = 0.010), compared with computer-navigated TKA. Patellar revision was significantly more likely in the IDI group., Conclusions: IDI TKA demonstrated no overall difference in early to mid-term revision rates compared with standard implantation methods. However, elevated rates of revision were seen with posterior-stabilized TKA, in patients ≤65 years of age, and for patellar revision, meaning that this method should be used with some caution and requires further study., Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background: Achieving soft tissue balance is an operative goal in total knee arthroplasty. This randomised, prospective study compared computer navigation to conventional techniques in achieving soft tissue balance., Methods: Forty one consecutive knee arthroplasties were randomised to either a non-navigated or navigated group. In the non-navigated group, balancing was carried out using surgeon judgement. In the navigated group, balancing was carried out using navigation software. In both groups, the navigation software was used as a measuring tool., Results: Balancing of the mediolateral extension gap was superior in the navigation group (p=0.001). No significant difference was found between the two groups in balancing the mediolateral flexion gap or in achieving equal flexion and extension gaps., Conclusions: Computer navigation offered little advantage over experienced surgeon judgement in achieving soft tissue balance in knee replacement. However, the method employed in the navigated group did provide a reproducible and objective assessment of flexion and extension gaps and may therefore benefit surgeons in training., Level of Evidence: Level I, RCT., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Bleeding-related wound complications cause significant morbidity in lower limb arthroplasty surgery. Patients who require therapeutic anticoagulation in the perioperative period are potentially at higher risk for these complications. This is a retrospective case-control study reviewing all primary total hip arthroplasties performed in a single center during a 5-year period and comparing outcomes of the patients on warfarin with a double-matched control group of patients not on warfarin. The warfarin group had a significantly higher risk of deep joint infection (9% vs 2.2%), hematoma/wound ooze (28% vs 4%), and superficial infection (13.5% vs 2.2%). Managing patients undergoing total hip arthroplasty with therapeutic anticoagulation is a balance between the risk of thromboembolic disease and bleeding-related complications. Improved understanding of this risk will better allow patients to make an informed decision regarding their elective arthroplasty surgery., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: The objective of routine outpatient assessment of well-functioning patients after primary total hip arthroplasty (THA) is to detect asymptomatic failure of prostheses to guide recommendations for early intervention. We have observed that the revision of THAs in asymptomatic patients is highly uncommon. We therefore question the need for routine follow-up of patients after THA., Methods: A prospective analysis of an orthopaedic database identified 158 patients who received 177 revision THAs over a four-year period. A retrospective chart review was conducted. Patient demographics, primary and revision surgery parameters and follow-up information were recorded and cross-referenced with Australian Orthopaedic Association National Joint Replacement Registry data., Results: One hundred ten THAs in 104 patients (average age 70.4 (SD 9.8 years)). There were 70 (63.6%) in total, 13 (11.8%) femoral and 27 (24.5%) acetabular revisions. The indications for revision were aseptic loosening (70%), dislocation (8.2%), peri-prosthetic fracture (7.3%), osteolysis (6.4%) and infection (4.5%). Only four (3.6%) were asymptomatic revisions. A mean of 5.3 (SD 5.2 and 1.9 (SD 5.3)) follow-up appointments were required before revision in patients with and without symptoms, respectively. The average time from the primary to revision surgery was 11.8 (SD 7.23) years., Conclusions: We conclude that patients with prostheses with excellent long-term clinical results as validated by joint registries, routine follow-up of asymptomatic THA should be questioned and requires further investigation. Based on the work of this study, the current practice of routine follow-up of asymptomatic THA may be excessively costly and unnecessary, and a less resource-intensive review method may be more appropriate., (© 2010 The Authors. ANZ Journal of Surgery © 2010 Royal Australasian College of Surgeons.)

An SRI dual Purkinje image (dPi) eye tracker was used to measure lens wobble following saccades with increasing accommodative effort as an indirect measure of ciliary muscle function in presbyopes. Ten presbyopic subjects executed 32 four-degree saccades at 1-s intervals between targets arranged in a cross on illuminated cards at each of 9 viewing distances ranging from 0.5- to 8-D accommodative demands. Post-saccadic lens wobble artifacts were extracted by subtraction of P1 (H(1)/V(1)) position signals from P4 signals (Theta(H)/Theta(V)), both of which were sampled by the eye tracker at 100 Hz. A ray tracing eye model was also employed to model the fourth Purkinje image shifts for a range of lens translations and tilts. Combining all saccades from all subjects showed a significant positive relationship between lens wobble artifact amplitude and accommodative demand. Eye model simulations indicated that artifacts of the amplitude measured could arise from either lens tilts (in the range of 2-4 degrees) or lens translations (in the range of 0.1 to 0.2 mm). Saccadic lens wobble artifacts increase with accommodative effort in presbyopes, indicating preserved ciliary muscle function and greater relaxation of zonular tension with accommodative effort. Variation across subjects may reflect differences in accommodative effort, ciliary muscle function for a given effort, and/or in intraocular anatomy.

Hip navigation was used as an assessment tool to compare ability to reproduce trial and definitive acetabular placement in total hip arthroplasty, using cemented and uncemented components. We demonstrated a significant difference in reproducibility between components. Of 20 uncemented cups, 4 (20%) deviated from the target inclination by 5 degrees or more compared to none of 21 in the cemented group (P = .048). Of the 20 uncemented cups, 7 (35%) deviated from the target version by 5 degrees or more compared to none of 21 in the cemented group (P = .003). This may explain higher rates of revision for dislocation with uncemented components. There was also a significant difference between the groups with regard to deviation from planned leg length (P < .001).

Purpose: To examine the relationship between uncorrected residual wavefront error and visual performance (VP) in rigid gas permeable (RGP) contact lens-wearing keratoconic eyes., Methods: Seven eyes from six subjects (six moderate, one severe) were studied (mean +/- SD age: 42.71 +/- 11.38 years). Significant corneal scarring was an exclusion criterion. Measurements were taken with RGP lenses in place. After pupil dilation, the VP measures of high contrast logMAR visual acuity (VA) and Pelli-Robson contrast sensitivity (PRCS) were measured through a 5-mm artificial pupil. Wavefront error was measured using a Shack-Hartmann wavefront sensor and calculated over 5 mm. For both VP and wavefront error, comparisons were made to previously collected normal values by calculating the interval encompassing 95% of normals, then reporting how many of the seven keratoconic eyes fell outside the normal interval. Additionally, second to sixth order aberrations were processed into four previously reported image quality metrics: root mean square of the wavefront (RMSw), root mean square of the slope (RMSs), average blur strength (Bave) and diameter containing 50% light energy (D50) and regressed against VP measures., Results: Five of seven keratoconic eyes fell outside the normal interval (-0.23 to 0.09) for VA and two of seven fell outside the normal interval (1.59 to 2.03) for PRCS. Five of seven keratoconic eyes fell outside the normal interval (0.07 to 0.35 microm) for total higher order RMS. Linear regressions demonstrated relationships between both VA and PRCS and the image quality metrics RMSw, D50, RMSs, and Bave with R values for VA = 0.30, 0.30, 0.47, 0.62, and PRCS = 0.21, 0.15, 0.45, 0.75 respectively., Conclusions: VP in RGP-wearing keratoconic eyes is reduced and higher order wavefront aberrations are elevated compared to normals. Metrics of retinal image quality demonstrate a relationship between keratoconic VP and residual wavefront aberrations. This relationship suggests developing corrections that more completely correct aberrations may improve visual performance in keratoconus.

We report root-mean-square (RMS) wavefront error (WFE) for individual aberrations and cumulative high-order (HO) RMS WFE for the normal human eye as a function of age by decade and pupil diameter in 1 mm steps from 3 to 7 mm and determine the relationship among HO RMS WFE, mean age for each decade of life, and luminance for physiologic pupil diameters. Subjects included 146 healthy individuals from 20 to 80 years of age. Ocular aberration was measured on the preferred eye of each subject (for a total of 146 eyes through dilated pupils; computed for 3, 4, 5, 6, and 7 mm pupils; and described with a tenth-radial-order normalized Zernike expansion. We found that HO RMS WFE increases faster with increasing pupil diameter for any given age and pupil diameter than it does with increasing age alone. A planar function accounts for 99% of the variance in the 3-D space defined by mean log HO RMS WFE, mean age for each decade of life, and pupil diameter. When physiologic pupil diameters are used to estimate HO RMS WFE as a function of luminance and age, at low luminance (9 cd/m2) HO RMS WFE decreases with increasing age. This normative data set details (1) the 3-D relationship between HO RMS WFE and age for fixed pupil diameters and (2) the 3-D relationship among HO RMS WFE, age, and luminance for physiologic pupil diameters.

Purpose: To determine the influence of exposure time and pupil size on a Shack-Hartmann (S/H) derived metric of forward scatter (MAX&#95;SD) using a physical model of nuclear cataract., Methods: A physical model eye was developed and mounted to a S/H wavefront sensor. The eye model consisted of a lens, variable pupil, simulated cataract, and retina. Located behind the pupil, a cuvette contained one of five polystyrene microsphere solutions simulating five levels of nuclear cataract severity. Cataract severity was described using a S/H derived metric of forward scatter (MAX SD), which measures aspects of forward scatter contained in the S/H lenslet point spread functions (PSF). To determine the impact of exposure time and pupil size, measurements of MAX&#95;SD were regressed against cataract severity for three different exposure times and three different pupil sizes., Results: MAX&#95;SD was well correlated to cataract severity. Exposure time had the largest influence, and pupil size had the smallest influence on the forward scatter metric. When pupil size and exposure time were allowed to vary and image saturation was allowed to occur, MAX SD explained 83% of the variance in cataract severity. Excluding images where saturation occurred, holding optimal exposure time constant, and varying pupil size, MAX&#95;SD explained 97% of the variance in cataract severity., Conclusions: The ability of the forward scatter metric derived from S/H measurements to predict cataract severity for a longitudinal study is optimized by selecting a patient-specific exposure at the initial cataract assessment to avoid saturation and maximize the dynamic range of the system. This patient-specific exposure should be used in all future visits.

If patient-centered medicine is to become a widespread reality in academic medical centers, educational initiatives must include reform of the medical record. The medical record is part of the hidden, or informal, curriculum of medical school and residency that defines for students and residents the essential ingredients of competent medical care. Whatever its merits, the conventional, problem-oriented medical record (POMR) is a pathology-oriented record that helps perpetuate a disease-focused, biomedical model of practice Patient-centered medicine requires a patient-centered medical record (PCMR), one that addresses the person and perspective of the patient as competently as it addresses the patient's disease. The author proposes a PCMR that includes a concise, upfront Patient Profile; speaks of "chief concerns," not "chief complaints"; makes Patient Perspective a captioned component of the History of Present Illness; replaces the POMR's formula SOAP (Subjective, Objective, Assessment, Plan) with HOAP (History, Observations, Assessment, Plan); includes important patient perspectives on the Problem List; and calls for additional, written attention to the person and perspective of the patient throughout the course of medical care Patient-centered records can guide and teach clinicians at every level of training and experience to practice patient-centered medicine. Moreover, such records can also provide measurable evidence that this teaching has been successful.

Purpose: To develop single-valued wavefront aberration metrics that correlate strongly with visual performance. The purpose of this study is to explore whether photopic high contrast visual acuity (VA) is an appropriate visual performance reference and whether mesopic and/or low contrast testing provides any advantage., Methods: Subjects from the Texas Investigation of Cataract Optics study (N = 148) ranged in age from 21.6 to 83.8 years and from clear lens to dense nuclear cataract. Visual acuity was measured under four conditions: photopic high (VA(PHC)) and low (VA(PLC)) contrast, mesopic high (VA(MHC)) and low (VA(MLC)) contrast (photopic = 280 cd/m(2), mesopic = 0.75 cd/m(2)). Variables were tested for compliance with normality (-2.00 < skew and kurtosis < 2.00) and transformed if required. Linear regression and Bland-Altman 95% limits of agreement (+/-1.96 SD) were used to examine relationships between VA variables and between VA and wavefront aberration metrics., Results: The two photopic measures VA(PHC) (skew = 2.57, kurtosis = 12.2) and VA(PLC) (1.67, 5.41) were poorly distributed, but the two mesopic measures VA(MHC) (0.88, 1.67) and VA(MLC) (0.29, -0.18) were normally distributed. Strong correlations existed between the (transformed) VA variables (R: 0.53 to 0.84). However, limits of agreement ranged over 0.30 to 0.42 logMAR, whereas retest data suggested a range of 0.15. All four were offered in stepwise multiple linear regression for 30 wavefront metrics: 20 included VA(MLC) alone, two included VA(PLC), two included VA(MHC) and six included both VA(MLC) and VA(MHC); R(2) averaged 25%., Conclusion: Although strongly correlated, low contrast and/or mesopic VA testing provides different information. Wave aberration metrics correlates better with VA(MLC) making this the visual performance test of choice.

Purpose: Quantify and localize lenticular forward scatter using Shack-Hartmann wavefront sensing (SHWS) as single-valued metrics and a scatter map, and to examine the relationships between forward scatter and backscatter metrics and visual acuity., Methods: We obtained SHWS images from 148 patients in the Texas Investigation of Cataract Optics study. Patient age was 22 to 84 years, with Lens Opacities Classification System III (LOCS III) nuclear opalescence (NO) scores ranging from 0.8 to 5.6. Visual acuities were measured at photopic (280 cd/m2) high (VA(PHC)) and low contrast (VA(PLC)) and mesopic (0.75 cd/m2) high (VA(MHC)) and low contrast (VA(MLC)). Scattering was described in a scatter map and by five single-valued metrics characterizing SHWS lenslet point spread functions. The relationships between scatter and visual acuity were tested using linear regression., Results: Visual acuities decreased proportional to both LOCS III NO (R2=up to 39%) and scatter metrics (R2=up to 21%). Stepwise multiple linear regression improved visual acuity prediction by including a backscatter and a forward scatter metric (R2 up to 51.2%). For the subjects over age 60 years (N=46, 68.8+/-6.12 years), the forward scatter metrics explain as much variance in visual acuities (R2=up to 29%) as LOCS III NO (R2=up to 26%). Combined they accounted for up to 48.8% of visual acuity variance., Conclusion: Forward light scatter can be quantified using SHWS and the resulting metrics explain significant variance in visual acuity, especially in the aging eye. Together with a backscatter metric they explain approximately 50% of the variance in VA.

A computer model that incorporates the monochromatic aberrations of the eye is used to determine the optimal pupil size for axial and lateral resolution as it applies to retinal imaging instruments such as the confocal scanning laser ophthalmoscope. The optimal pupil size for axial resolution, based on the aberrations of 15 subjects, is 4.30 mm +/- 1.19 mm standard deviation (sd), which is larger than that for lateral resolution [2.46 mm +/- 0.66 mm (sd)]. When small confocal pinholes are used, the maximum detected light is obtained with a pupil size of 4.90 mm +/- 1.04 mm sd. It is recommended to use larger pupil sizes in imaging applications where axial resolution is desired.

A new technique for the measurement of subsidence of the femoral components is proposed. The method relies on the implantation of two ball markers around the femoral stem. A single radiographic image of the hip is analysed using image-processing techniques to minimize subjectivity related to manual identification of landmarks. Dimensions of the stem are used to correct for magnification and out-of-plane rotations resulting from radiographic positioning. This technique has been applied to a specific design of implant (Exeter). A study of the effect of radiographic positioning has been conducted using a cadaveric bone phantom. Results for the variation in the measurement of axial migration compared to the neutral position (in millimetres) were: 0.942 (10 degrees extension); 0.347 (20 degrees flexion); -0.435 (40 degrees internal rotation); 0.187 (30 degrees external rotation) for distances measured between the bone marker and the implant. Results for distances measured between the implant and the cement centralizer were: 0.107 (10 degrees extension); -0.277 (20 degrees flexion); 0.085 (40 degrees internal rotation); 0.280 (30 degrees external rotation). The variations from within a more realistic range of positions demonstrate that axial migration measurements of ca. 0.5 mm between the bone and implant, and less than 0.3 mm between the implant and the bone cement, may be expected.

We have reviewed 202 consecutive primary hip replacements using a Freeman cemented femoral component after a mean period of follow-up of 64 months (23 to 113). There was only one revision for aseptic loosening. Retention of the femoral neck may act to reduce the torsional and shear forces at the implant-cement interface and may provide a seal against the migration of polyethylene-laden joint fluid in the potential joint space. The cemented Freeman femoral component with retention of the femoral neck was successful for up to nine years.

We reviewed 120 consecutive primary total hip replacements in 109 patients in whom a Freeman uncemented metal-backed component had been used. Acetabular components were used with a Freeman neck-retaining stem in one of three configurations: cemented smooth stem, uncemented smooth stem or uncemented ridged stem. After a mean follow up of 72 months (62 to 113) there were nine cases of aseptic loosening; a survivorship at eight years of 83%. In addition, more than one-third of the remaining surviving cups showed loosening radiologically. The Freeman acetabular component demonstrated a characteristic pattern of loosening on radiographs. The high incidence of aseptic loosening can be explained by poor design and material failure.

Avulsion of the tibial tuberosity was diagnosed in six of seven greyhound littermates aged five and a half months. The puppies showed hindlimb lameness of varying severity. Radiological assessment of affected stifle joints revealed partial or complete avulsion of the tibial tuberosities. In four puppies the lesions were bilateral. Euthanasia of the two most severely affected puppies was performed; the changes observed on histopathological examination of their cranioproximal tibiae suggested that the underlying lesion was that of osteochondrosis. A hereditary predisposition in greyhounds to osteochondrosis of the physis between the apophysis and the cranioproximal tibial diaphysis is postulated.

We reviewed a consecutive series of 527 uninfected hip replacements in patients resident in the UK which had been implanted from 1981 to 1993. All had the same basic design of femoral prosthesis, but four fixation techniques had been used: two press-fit, one HA-coated and one cemented. Review and radiography were planned prospectively. For assessment the components were retrospectively placed into two groups: those which had failed from two years onwards by aseptic femoral loosening and those in which the femoral component had survived without revision or recommendation for revision. All available radiographs in both groups were measured to determine vertical migration and examined by two observers to agree the presence of radiolucent lines (RLLs), lytic lesions, resorption of the neck, proximal osteopenia and distal intramedullary and distal subperiosteal formation of new bone. We then related the presence or absence of these features and the rate of migration at two years to the outcome with regard to aseptic loosening and determined the predictive value of each of these variables. Migration of > or = 2 mm at two years, the presence of an RLL of 2 mm occupying one-third of any one zone, and subperiosteal formation of new bone at the tip of the stem were predictors of aseptic loosening after two years. There were too few lytic lesions to assess at two years, but at five years a lytic lesion > or = 2 mm also predicted failure. We discuss the use of these variables as predictors of femoral aseptic loosening for groups of hips and for individual hips. We conclude that if a group of about 50 total hip replacements, perhaps with a new design of femoral stem, were studied in this way at two years, a mean migration of < 0.4 mm and an incidence of < 10% of RLLs of 2 mm in any one zone would predict 95% survival at ten years. For an individual prosthesis, migration of < 2 mm and the absence of an RLL of < or = 2 mm at two years predict a 6% chance of revision over approximately ten years. If either 2 mm of migration or an RLL of 2 mm is present, the chances of revision rise to 27%, and if both radiological signs are present they are 50%. If at five years a lytic lesion has developed, whatever the situation at two years, there is approximately a 50% chance of failure in the following five years. Our findings suggest that replacements using a limited number of any new design of femoral prosthesis should be screened radiologically at two years before they are generally introduced. We also suggest that radiographs of individual patients at two years and perhaps at five years should be studied to help to decide whether or not the patient should remain under close review or be discharged from specialist follow-up.

The onset of growth retardation was investigated in fetal lambs following experimental infection of pregnant ewes with Border Disease virus (BDV) on day 53 of pregnancy. Fetuses from control and infected ewes were harvested at weekly intervals between day 60 and day 95 of gestation and morphometric studies were completed on tibial radiographs and tibial growth cartilage metaphyseal junctions. Mean tibial areas were significantly reduced (P < 0.01) in fetuses from infected ewes at 35 and 42 days after infection and growth cartilage metaphyseal junctions were less mature in fetuses from infected ewes at 42 days after infection. Positive immunostaining for BDV antigen was demonstrated in the brains of all fetuses from infected ewes between 14 and 42 days after infection. Attempts to demonstrate BDV antigen in bone proved unsuccessful. It is concluded that intrauterine growth retardation is an early manifestation of BDV infection in lambs and that the process is initiated shortly following infection of the fetus.

We compared the radiological appearances and survival of four methods of fixation of a femoral stem in 538 hips after follow-up for five or ten years. The fixation groups were: 1) press-fit shot-blasted smooth Ti-A1-V stem; 2) press-fit shot-blasted proximally ridged stem; 3) proximal hydroxyapatite (HA) coating; and 4) cementing. Survival analysis at five to ten years showed better results in the HA-coated (100% at five to six years) and cemented stems (100% at 5 to 6 years) than in the two press-fit groups. There was a higher mean rate of migration in the smooth and ridged Ti-A1-V shot-blasted press-fit groups (0.8 mm/year and 0.6 mm/year, respectively) when compared with the HA-coated and cemented prostheses (both 0.3 mm/year). More radiolucent lines and osteolytic lesions were seen in the press-fit groups than in either the HA-coated or cemented implants, with a trend for a lower incidence of both in the HA compared with the cemented group. Proximal osteopenia increased in the press-fit and cemented prostheses with time, but did not do so in the HA group. There was a higher incidence of resorption of the femoral neck with time in the cemented group than in the other three. We conclude that the HA and the cemented interfaces both provide secure fixation with a trend in favour of HA. The cemented prosthesis meets the suggested National Institutes of Health definition of 'efficacious' at ten years.

A two-year-old West Highland white terrier, which had failed to thrive from six months of age, presented with acute onset dyspnoea. Radiography showed a diffuse pulmonary infiltrate throughout both lungs. Haematological abnormalities were an absolute neutrophilia and eosinophilia. Postmortem examination revealed uniform consolidation of both lungs which was defined histologically as a verminous granulomatous pneumonia. Metastrongyle larvae, isolated from the pulmonary tissue, had the morphological characteristics of Filaroides species. On the basis of the pathological changes and the larval morphology, a presumptive diagnosis of F hirthi pneumonia was made. This is believed to be the first report of disease due to this parasite in Ireland.

Many alternatives or supplements to "principalism" seek to reconnect medical ethics with the thoughts, feelings, and motivations of the persons directly involved in ethically troublesome situations. This shift of attention, from deeds to doers, from principles to principals, acknowledges the importance of the moral agents involved in the situation-particular practitioners, patients, and families. Taking into account the subjective, lived experience of moral decision-making parallels recent efforts in the teaching of medicine to give the patient's subjectivity-his or her personal experience of being sick or disabled epistemological parity with scientific medicine's "objective," biomedically-oriented view of the person's sickness or disability. Moreover, the shift from principalism to principals signals a growing realization that ethical problems in the profession of medicine are inseparable from its practice. Philosophers and other humanists working in medicine should resist the temptation to institutionalize a professional role as solver of ethical problems, clarifier of values, or mediator of disputes and work instead to help practitioners practice medicine reflectively.

Partially purified Staphylococcus aureus Beta-haemolysin and a S. aureus strain (FGH28), isolated from a clinical case of bovine mastitis, known to produce in vitro Beta-, but neither Alpha- nor Delta-haemolysins were each injected separately into the mammary gland of mice. Relative purity and in vitro biological activities of this preparation were assessed. The effects of both the partially purified preparation and the S. aureus strain injected were assessed in terms of mortality, clinical appearance, macroscopic and microscopic changes, recovery of organisms from the inoculated glands and biological activity in supernatants from ground mammary glands. When injected alone, partially purified Beta-Haemolysin was not found to be an important virulence factor, being a diffuse infiltration of neutrophils into the alveoli the pathological effect observed following its inoculation. Vascular lesions were observed, in the most severe cases, following injection of S. aureus FGH28.

A non-suppurative encephalitis accompanied by intraneuronal intranuclear inclusions were observed in the brain from a cow that died within 10 hours of developing nervous signs. Immunogold-silver staining located Aujeszky's disease virus antigen in neuronal cytoplasm and the virus was isolated from large volumes of suspensions of nervous tissues and tonsils. Fattening pigs in adjacent buildings had high antibody titres to Aujeszky's disease virus. The methods by which the cow could have acquired infection are considered, and the significance of transient low titres of antibodies to Aujeszky's disease virus in in-contact cows is discussed.

A method was investigated for the sensitive radiochemical assay of milk protein transformations. beta-Casein was reductively methylated with NaBH4 and H14CHO giving a product of spec. act. 4.42 microCi/mg in which a maximum of 12% of the lysine residues were labelled. Methylation did not alter the electrophoretic or chromatographic properties of the protein, or its pattern of proteolysis by plasmin. The substrate susceptibility of 14C-methylated beta-casein towards plasmin was determined by measuring radioactivity transfer to the proteolytic fragments gamma 2- and gamma 3-casein. Compared with the native protein, no decrease in substrate susceptibility was detected. The presence in milk of the plasmin-like enzyme, milk proteinase, was demonstrated and its activity at 4 degrees C was quantified by examination of the fragmentation pattern of added 14C-methylated beta-casein. It was concluded that 14C-methylated protein substrates, prepared by reductive methylation, are well suited to the study of hydrolytic enzymes and that they can provide valuable information on milk protein transformations. In particular, no interference was encountered with the rate of cleavage by plasmin when the level of methylation was kept to a minimum.

During the past few years, synthetic DNA, used as a primer in DNA polymerization, in site-directed mutagenesis or as a probe in gene selection, has assumed a central role in recombinant DNA technology (1). This was made possible by the development of methods for efficient solid phase chemical synthesis. Deoxyribonucleotides are ideally suited to solid-phase synthesis since their relative chemical uniformity allows for application of oligodeoxyribonucleotide (oligonucleotide) purification techniques, which are largely dependent on chain length. Hence, the potential disadvantage of omitting purification after each coupling step is minimized. This contrasts with peptide synthesis in which purification of the final product is more difficult, thereby placing greater demands on coupling efficiency. In practice, coupling efficiencies of at least 95% are now attainable in oligonucleotide synthesis because of the availability of highly reactive mononucleotides and specially developed coupling catalysts. In optimized systems, this allows for synthesis of oligomers greater than 50 bases in length.

When anti-sera to bovine pepsinogen and chymosin (rennin) was used, immunoreactive tumor cells were found in 12 of 23 gastric adenocarcinomas irrespective of the tumor subtype, degree of differentiation, or the presence or absence of intestinal metaplasia in the adjacent gastric mucosa. Nine of ten lymph node metastases contained immunoreactive tumor cells. Except for focal positively staining acini in Brunner's glands the antibodies did not stain normal small intestine or areas of intestinal metaplasia. Although intestinal metaplasia is a predisposing factor in gastric carcinoma it may be irrelevant to its histogenesis and differentiation. Instead, the mucus neck cells, being the stem cells of the normal gastric mucosa, may be the target of malignant transformation in gastric carcinoma.

Chromatography of glutaraldehyde-fixed skim-milk on controlled-pore glass (CPG-10, 300 nm) gave three micellar fractions whose averaged diameters, measured by electron microscopy, decreased progressively with increasing elution volume. Casein micelles with diameters up to 680 nm were detected. The casein composition of the same fractions from unfixed skim-milk was determined. As the fraction elution volume increased, kappa-casein varied from 7.7 to 11.4% of total casein, giving alpha s/kappa ratios of 6.1, 4.7 and 3.3. A plot of kappa-casein content versus micelle surface-to-volume ratio for skim-milk and the column fractions approximated to a straight line. Re-calculation of the published results from two other studies also gave linear relationships between kappa-casein content and surface area for artificial micelles. The three regression lines thus obtained had small intercepts. It was concluded that the data indicated the same fundamental structure for casein micelles, with a predominant surface location for kappa-casein, whether the micelles are natural or artificial and whether they are aggregated by Ca2+ alone or by Ca2+ together with calcium phosphate-citrate complex.

Multivariate cluster analysis of data on 128 asthmatic children resulted in the identification of 8 major discriminating variables. Stepwise divisions by this computer programme resulted in the formation of 6 grades of severity. There was significant correlation between higher grades of severity and early onset of the disease (P less than 0.02). There was also significant correlation between higher grades of severity and greater use of interval medications (P less than 0.002). However, 27.3% were receiving inadequate interval medications in respect of their grade of severity. Assignation of a 5-point scale to each of the 8 major discriminating variables resulted in the generation of computer-designated scores commensurate with each grade of severity. This was coupled to current recommendations for stepwise maintenance medications appropriate for each grade. This Score Card system for maintenance management of childhood asthma may prove useful in busy clinical settings.

We interviewed the parents of 128 asthmatic children about their knowledge and misconceptions of asthma. Two-third or more gave correct responses to questions on aetiology and pathogenesis, pathophysiology, symptomatology, precipitants and outcome of asthma. A control group of parents of 110 children admitted to the hospital with minor surgical complaints performed equally well on the knowledge questions, except for four sub-questions: (1) allergy as an aetiologic factor in asthma (64.5% vs 83.6%, P = 0.002), (2) constriction of airways as a bodily change during an asthmatic attack (75.4% vs 91.3%, P = 0.004), (3) cough as a symptom of asthma (82.7% vs 99.2%, P less than 0.001) and (4) change in weather (81.0% vs 95.5%, P = 0.002) or cold weather (60.9% vs 74.2%, P = 0.015) as triggers of asthma. However, a significant minority of both groups of parents were found to harbour misconceptions about asthma. Between 10-20% believed that poor care, inappropriate diet during pregnancy or premature birth can predispose a child to asthma. About one-third believed that bodily changes during an asthmatic attack include loss of control or paralysis of chest muscles, infection of lungs and compression of the lungs by the stomach. Also about one-third believed that swallowing a hard object or touching a poisonous plant can set off an asthmatic attack. Some 10% believed that diarrhoea is a symptom of asthma, while 50% regarded sore throat as a symptom. Up to 40% believed in restriction of outdoor play by asthmatic children.(ABSTRACT TRUNCATED AT 250 WORDS)

The parents of 128 children with asthma were interviewed about their knowledge of asthma medications. Simple understanding of the modes of action of these drugs was present in only 42.2% (for beta 2-agonists), 12.1% (methylxanthines), 11.7% (cromoglycate), 0% (inhaled corticosteroids), and 3.6% (oral corticosteroids) of parents. Simple understanding of when to use these drugs was present in 13.4% (beta 2-agonists), 4% (methylxanthines), 50% (cromoglycate), 47.1% (inhaled corticosteroids), and 0% (oral corticosteroids). Some understanding of the side effects was observed in 51.6% (beta 2-agonists), 40.4% (methylxanthines), 10% (cromoglycate), 5.9% (inhaled corticosteroids), and 25% (oral corticosteroids). Poor parental knowledge about the pharmacology of asthma was underlined by the inclusion of antibiotics, antihistamines, and decongestants as medications used in asthma. This study also uncovered the continuing misuse of compound methylxanthine preparations and non-selective sympathomimetics in a small percentage of patients.

Skim-milk was fractionated by permeation chromatography on CPG-10 (300 nm) at 20 degrees C with synthetic milk serum. The elution profile, which was highly reproducible, showed 3 partly resolved peaks. On treatment with 0.1% glutaraldehyde before chromatography, a similar profile was obtained indicating no appreciable micellar dissociation during chromatography of the milk. The casein composition of the eluent fractions, determined by quantitative chromatography on hydroxyapatite, showed that 12.1% of total casein was associated with the low molecular weight peak. The micelle content of beta- and kappa-casein increased with increasing elution volume, and the alphas/kappa ratio showed a progressive diminution from 4.3 to 2.3. Large differences were found in the colloidal phosphate contents and the weight average diameters of the micelle fractions which clearly show that CPG-10 fractionates on the basis of molecular size.