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Patients with central scotoma have poor fixation stability and poor visual acuity. Acoustic biofeedback training can be an effective way to train such patients to eccentrically fixate. This study analyses the mean retinal sensitivity, saccadic velocity, and fixation stability after acoustic biofeedback training and shows correlation with age and scotoma size.Patients with irreversible central scotoma in both the eyes secondary to macular diseases were selected. After undergoing comprehensive low vision assessment, 19 patients who were willing were recruited for the acoustic biofeedback training to the better eye in 10 sessions, using the MP-1 Microperimeter. Mean retinal sensitivity, saccadic velocity, fixation stability before and after the acoustic biofeedback were recorded.There were 17 men and two women. Ages ranged from 19-94 years (mean 54.63 ± 24.66). The scotoma size ranged from four to 20 degrees. Ten patients had age-related macular degeneration, four had Stargardt disease, three had traumatic macular scar, two had scarred myopic choroidal neovascular membrane, and one had myopic macular degeneration. The vision improved from 1.06 ± 0.36 to 0.86 ± 0.33 logMAR (p 0.0001). The mean retinal sensitivity improved from 2.1 ± 2.9 dB to 2.7 ± 3.1 dB (p = 0.01), with negative correlation with age (p = 0.01) and scotoma size (p = 0.02). Fixation stability improved with reduction in the bivariate contour ellipse area (p = 0.01). It showed negative correlation with age (p = 0.02) and scotoma size (p = 0.10). The saccadic velocity reduced from 0.34°/second to 0.26°/second but was not significant (p 0.99). The majority (58 per cent) had their preferred retinal locus superior to the fovea. There was good agreement between bivariate contour ellipse area and MP-1 Microperimeter inbuilt fixation parameters. The effect was maintained at six months with slight reduction in fixation stability.Acoustic biofeedback can improve fixation behaviour, visual acuity and retinal sensitivity in patients with central scotoma. The results are better with younger age and smaller scotoma size.

Rising rate of high energy trauma, mainly due to increasing life expectancy of the population on a global scale in recent decades and more intense daily activity, involves the need to address the increase of more complex fractures, thus putting to the test the experience of trauma surgeon and the quality of various osteosynthesis materials. Metallic materials designed for orthopedic implants must present a group of properties that strength, biocompatibility and resistance to degradation (corrosion or wear) are of primary importance. To reach these objectives, the materials used in the manufacture of orthopedic implants must meet standard requirements. These requirements include primarily standard chemical composition, microstructure and macroscopic appearance. In this paper we present a study to determine the cause of degradation of osteosynthesis material. The most frequent causes of degradation include poor or unstable fixation of osteosynthesis or material defects. A valuation technique, including optical and scanning electron microscopy (SEM) was used to assess aspects of macroscopic and microstructural degradation and chemical composition of implants. These assessments showed that both design errors and inappropriate surgical procedures were due to failures.

Children may present in early infancy for evaluation of decreased visual responsiveness. Most such infants have systemic or ocular abnormalities that explain their poor fixation and tracking. Some infants, however, have no other medical or ocular problems. This study evaluated prognostic factors in this latter group of otherwise normal infants with decreased visual responsiveness.This was a retrospective cohort study in which medical records of infants evaluated for decreased visual responsiveness were reviewed to identify children who had no history of premature birth or systemic problems associated with developmental delay. Examination findings that were predicted to indicate a good prognosis included: the presence of some reaction to light, normal pupil responses, no nystagmus, and no structural ocular abnormalities. Follow-up information was obtained from office visits and telephone interviews. Main outcome measures were visual acuity and developmental status.Thirty-two children met the criteria noted above. Six were excluded due to lack of follow-up. Four were normal by the time of their initial examination. Follow-up for the remaining patients ranged from 3 months to 11 years (mean 2.94 years). One patient developed strabismus and required surgery. The remaining patients all had normal vision and development.Otherwise normal infants who present for evaluation of decreased visual responsiveness have a good prognosis if they have some reaction to light, normal pupil responses, absence of nystagmus, and no structural ocular abnormalities. The developmental prognosis for these infants appears to be good. Additional testing at the time of initial evaluation is not indicated.

The aim of the study was to determine whether the order of cell collection (ie, obtaining either endocervical first or ectocervical cells first) has an effect on the quality of the Papanicolaou smear. 1129 smears were obtained using an Ayre spatula and an endocervical brush. In 564 cases, the endocervical brush was used first, and in 565 cases, the spatula was used first. The number of smears obscured by blood, the smears without endocervical component, and the smears with poor fixation were compared between the two groups. More smears were partially obscured by blood when brush was used first (78, 13.8% compared with 48, 8.5%, P = 0.004). No endocervical component was found in seven (1.2%) smears from the brush-first group compared with five (0.9%) of the spatula-first group, which is an insignificant difference. There were no significant differences in the number of poor-fixated smears, too-thick smears, and satisfactory smears but limited by inflammation between the two methods. The quality of the Papanicolaou smear can be improved by using the Ayre spatula first followed by the endocervical brush. Fewer smears will be contaminated by blood which may result in more squamous intraepithelial lesions being detected.

Objective To describe multifocal electroretinogram (mfERG) responses in 2 patients with nonorganic visual loss and in 11 eyes of 6 healthy persons who suppressed their mfERG responses. Design Observational case series. Methods The mfERG results were recorded in all individuals using the Veris Science 4.2 instrument. All subjects were instructed to adjust the hexagonal test pattern so that it was in best focus. A second mfERG was recorded subsequently in volunteers who attempted suppression with inattention and poor fixation and by adjusting the focus to greatest blur. Main outcome measures Amplitude and latency of mfERG responses. Results Suppressed mfERGs in patients with nonorganic visual loss and healthy volunteers demonstrated reduced amplitude, especially centrally. Amplitude reduction was statistically significant in the postsuppression as compared with the presuppression recordings in wave forms N1 and N2. Statistically significant shortening of postsuppression implicit times of P1 and N2 waveforms also was demonstrated. Conclusions The mfERG responses may be suppressed voluntarily. Amplitude may be reduced. In contrast to most reported pathologic conditions, the implicit time is shortened.

Cobalt alloys have been used successfully as bearings since the earliest days of arthroplasty, now seeing use in the overwhelming majority of knees and hips. Although reports of fracture, corrosion, and other unexpected events leading to revision are sporadically found throughout the literature over the last 3 decades, failure reports involving cobalt components have historically been dwarfed by failure reports of polyethylene oxidation, osteolysis, and poor fixation, among others. The current issue is a reminder that the human body and its permanently implanted devices constitute a fragile system, and even small perturbations of this system from cobalt alloys can result in untoward events with devastating outcomes. Through a thematic selection of case reports, the importance of good science and learning from the patient is underscored. Over the last decade, we have seen an uptick in metal-related failure reports secondary to wear of metal-on-metal (MoM) articulations. Much of the science aimed at understanding the root problem has been outstanding and exceptionally informative for future implementation of any bearing couple, not just MoM. The in vitro focus has necessarily been on discrete contributors to the problem such as inclination angle, cup opening, materials, head size, patient selection, and so forth. Due in large part to these studies and registry-related reports of patient outcomes,MoMusage is now

One hundred twenty patients (22 men, 98 women; 144 knees) with uncemented Freeman-Samuelson total knee arthroplasty were followed prospectively. Eighty-one patients had rheumatoid arthritis and 39 patients had osteoarthrosis. The mean follow-up period was 6.8 years. Three different types of tibial components were used: a high-density polyethylene component without stem, a metal-backed tibial component without stem, and a metal-backed tibial component with stem. Progressive varus tilting turned out to be an early sign of failure and occurred in 22% of the tibial components. Revision of the tibial component was done in 17 knees. Survival analysis with revision as endpoint revealed a survival rate of 79% at a follow-up period of 10 years. Cementless fixation of this design using macrointerlocking pegs and no other stabilization resulted in poor fixation and a high revision rate and cannot be recommended.

Comminuted supracondylar femur fractures in the elderly are often treated with either retrograde femoral nailing or locked plating. Early weight-bearing is typically restricted after fixing supracondylar fractures, thereby impairing the patient’s mobilization. In general, surgeons are more comfortable allowing early weight-bearing of long bone fractures after nailing rather than plating, but early studies of retrograde nails for supracondylar fractures using standard distal locking showed poor fixation compared with locked plating.Copyright © 2012 by ASME

A total of 101 patients (total group) with primary large angle esotropia who had primary bimedial rectus recession (BMR) of 6.5 mm or more were reviewed in a retrospective study. The average pre-operative size of the deviation was 63.5 prism diopters (PD) for near and 58.2 PD for distance. Of these, 26 patients (group I) attended for one post-operative visit only. The remaining 75 patients (group II) were followed for an average period of 17.7 months. Among group II patients there was an average shift in the post-operative deviation towards divergence consisting of-6.4 PD for near and-5.5 PD for distance. The alignment (deviation of 10 PD or below) rate in the first postoperative visit was 31.7%; undercorrection was 60.4% and overcorrection was 7.9%. At the end of the period of follow-up the above rates were 40%, 42.7%, and 17.3% respectively without further surgery. This increase in the overcorrection rate was solely derived from the initially aligned patients. Amblyopia and/or poor fixation were found to be of significance in the production of overcorrection. There was no direct relationship between the age of surgery, duration of follow-up or the degree of the BMR and the rate of correction. Among group II patients, post-operative ocular movements analysis revealed limitation of adduction of-0.5 to-0.75 (out of scale 0 to-4.00) in 22.7% (17/75) and-1.00 to-1.50 in 6.7% (5/75). None had more than-1.5 limitation of adduction. Large BMR is an acceptable surgical modality for the management of large angle esotropia. It has approximately 50% alignment rate. Slight undercorrection is recommended especially in the presence of significant amblyopia and/or poor fixation. No significant limitation of adduction was encountered.

Endovascular grafts (EVG) are stent grafts implanted percutaneously to repair aortic aneurysms. The primary source of fixation of the EVG is the friction from radial forces generated by graft over-sizing. Although a 10–20% over-sizing is common, it may range from 0 to 45% [1]. A clinical study on patient outcomes noted high migration rates when oversizing was greater than 30%. A recent in vitro study of barbed EVGs by our group found that greater than 30% oversizing results in decreased fixation strength quantified by the force needed to pullout the graft from the aorta [2]. In that study, based on anecdotal visual observation, we hypothesized that grafts with excessive oversizing may be folding, resulting in poor fixation strength. In this study, we ranked the level of folding noted in EVGs with varying oversizing in order to test that hypothesis.Copyright © 2010 by ASME

To calibrate oculokinetic perimetry (OKP) as developed by Damato in terms of conventional perimetric threshold values, 33 eyes with either glaucoma or ocular hypertension were tested with a standard Humphrey Field Analyzer using the Central 30-2 test and twice with a 26-point OKP chart. The frequency of seeing of the OKP test spot was plotted against 30-2 thresholds. This showed a weak relation between the two tests. Subsequently eyes that were considered to have had poor fixation were omitted, but false positive and false negative results still occurred in 19 remaining eyes. To check whether Troxler's effect (local adaptation) might have caused false positives, 6 subjects were tested with OKP, controlling the fixation times. Increasing the fixation time from ‘very short’ to 2 and 5 seconds yielded more ‘not seen’ responses in OKP. False negative data were found to occur preferentially in border areas of visual field defects. The average frequency of seeing curve over all data showed a 50% frequency of seeing for the OKP stimulus at a 14.6 dB equivalent conventional threshold value. The spreading of the curve was 7 dB (95% confidence interval 28 dB).

Cementless total knee arthroplasty (TKA) implants were designed as an alternative to cemented implants. They were touted to provide long-term fixation without the fear of cement debris particle generation and cement degradation resulting in late prosthetic loosening and failure. They were envisioned as a superior solution for TKA in younger patients. However, critical studies revealed a unique set of complications, which included poor fixation as evidenced by frequent occurrence of radiolucent lines, aseptic loosening, osteolysis, and patellar polyethylene dissociation from metal-backed cementless patellar components. At the same time, cemented prostheses continue to yield excellent results. To address some of the issues with cementless implants, porous metal devices have been produced. Although in vitro and early in vivo clinical studies show promising results, these devices must be measured against cemented fixation, which continues to be the "gold standard" in TKA.

The use of suture anchors and tacks around the shoulder requires a thorough knowledge of the proper use of the devices and how to insert them. Although typically not technically demanding, suture anchors and tacks can present unique and frustrating challenges to the patient and the surgeon. These challenges can occur whether the procedure is performed via an open or arthroscopic approach, but knowledge of the potential challenges may optimize the surgical result and prevent complications. Complications can be categorized as technique-related or device-related issues (mechanical or biologic failure). Techniquerelated complications include problems with the delivery systems, anchor malpositioning, and suture management issues, such as knots not sliding. Device-related complications include implant fracture, migration secondary to poor fixation, synovitis from implant degradation, and osteolysis. This review describes the prevention of these and other complications, addresses the indications or need for intervention, and suggests potential solutions when intervention is indicated.

Objective: To assess the effect of rehydration on air-dried Pap smears and to compare them with conventional, wet-fixed smears. Study Design: Paired cervical smears were obtained from 419 women. One set was labelled "Routine" (fixed immediately in 95% ethanol) and the other, "Rehydrated" (air-dried, rehydrated and then fixed). The latter were further subdivided into groups A-F depending on the duration of air drying. The staining quality of the smears was assessed, after adequate blinding to remove bias, and graded. The x² test was performed to compare parameters in the two sets of smears. Results: Of the 397 pairs found to have adequate cellularity, 6% of the Routine group and 4% of the Rehydrated were "unsatisfactory due to poor fixation." Smears rehydrated within two hours of air drying as well as those refrigerated within two hours and rehydrated after 48 hours produced a staining quality as good as that of the conventional, wet-fixed smears. Rehydration caused lysis of red blood cells in the background. Conclusion: Rehydration of air-dried Pap smears within two hours of preparation produces staining quality equal or superior to that of conventional, wet fixed ones. It has the added advantage of being less cumbersome for the clinical personnel involved in smear making.

Toxicologic pathology concerns the effect of potentially noxious products on the body. Toxicologic pathology differs in approach and methodology from diagnostic pathology. Many short-term studies are conducted to elucidate the mechanism of action of the test compound, to give some idea of its toxicity and to identify possible target organs. These studies incorporate standard histopathologic and clinical pathologic techniques. Sometimes specialized techniques, including electron microscopy, immunohistochemistry, autoradiography, and quantitative morphometry, are warranted. The first goal of toxicologic pathology is to establish the precise degree of risk posed to the test animals under the controlled exposure conditions. The process is similar to diagnostic pathology in lesion evaluation but differs in the manner in which data are compiled. Most of the factors that influence evaluation of morphologic change (e.g., poor fixation of tissue) have the undesirable effect of increasing the variability within groups and subsequently the range of data that the pathologist is forced to accept, which decreases the sensitivity of the methods used. The chapter describes factors influencing the evaluation of altered morphology.

The incorporation of specimen adequacy as an integral part of the report has been widely acknowledged as one of the most important contributions of TBS. The 1988 Bethesda System listed potential reasons for designating a specimen other than fully Satisfactory but did not incorporate specific criteria for the evaluation of specimen adequacy. Participants at the 1991 Bethesda System Workshop and others in the cytopathology community voiced the need for guidance in this area. In response, the Criteria Committee was charged with the development of morphologic criteria for the evaluation of adequacy.

Purpose of study: Transarticular screws are an important option for managing C1–C2 instability, although long-term follow-up on efficacy, safety and application to complex occipitocervical reconstructions is required. To address these issues, we present our experience with transarticular screw fixation in 51 consecutive, prospective cases with a mean follow-up of over 2 years. Methods used: Indications for surgery included trauma (n=23), rheumatoid arthritis (n=13), failed fusion (n=12), degenerative instability (n=3), osteomyelitis (n=1) and os odontoidum (n=1). A C1–C2 fusion alone was performed in 37 cases, and transarticular screws were used as part of a complex reconstruction in 14 cases. Ninety-eight screws were positioned; four patients had a single C1–C2 screw. All cases were evaluated by lateral flexion-extension films. Postoperative computed tomography (CT) with thin cut reconstruction was obtained in 31 cases (60 screws). An index of relative anterior/posterior subluxation was measured on midline sagittal reconstructions. of findings: There were no neurological complications or vertebral artery injuries. A solid fusion was obtained in 46 of 51 cases with four stable fibrous unions and one asymptomatic pseudarthrosis. By CT criteria, screws were in excellent (n=20), good (n=17), acceptable (n=14) and poor (n=2) position. We found a strong correlation between greater than 4 mm of C1–C2 posterior subluxation and nonoptimal screw position (p Relationship between findings and existing knowledge: The findings in the present study validate the use of transarticlar screw fixation to manage complex craniocervical problems including revision and rheumatoid cases. The zero incidence of neurovascular injury compares favorably with published series that quote up to a 1.8% incidence of vertebral artery injury. Overall significance of findings: Transarticular screws represent an important technique to stabilize the C1–C2 joint and with experience can be placed with minimal risk. Cases of atlantoaxial instability with greater than 4 mm of nonreducible posterior subluxation are associated with poor fixation and should be considered a relative contraindication for this technique. Disclosures: Device or drug: transarticular screw fixation. Status: investigational. Conflict of interest: Michael Fehlings, grant research support, Synthesspire, Medtronic Sofamor Danek.

Introduction: The effect of changing the alignment of the corneal surface in relation to the plane of the videokeratoscope mires in computer-assisted topographic corneal analysis was evaluated. Methods: The corneas of five subjects were analyzed with the visual axis at 0 ° , 2.5 ° , 5 ° , and 10 ° below the central axis of the videokeratoscope. The relative steepness of the inferior and superior cornea was compared using inferior-superior (I-S) values at each deviation from the central axis. A similar analysis was performed on three aspheric test surfaces with different central curvatures. Results: The difference in the relative steepness of the inferior and superior cornea was found to increase in proportion to the deviation from alignment with the central axis in both the test subjects and the aspheric test surfaces. Conclusion: This change in relative steepness produces a pattern that mimics keratoconus and can be seen at deviations of less than 5 ° in some patients. The increase in the I-S value was significant at 5 ° of deviation ( P

We have evaluated 30 Mittelmeier hips on an average 3.3 years after the operation. Seven hips had been revised because of severe pain and mechanical loosening and one because of fracture of the threaded ceramic cup. Only five of the remaining 22 hips were asymptomatic. There was radiographic migration of the acetabular and femoral components in more than one third of the hips and increased scintimetric values around the femoral component in all but two hips. Unfavorable design of the Mittelmeier prosthesis may be an important etiologic factor contributing to poor component fixation and inferior clinical results.

We analyzed the electroretinogram elicited by pattern stimuli (PERG) in 29 patients with unilateral optic nerve disease. The normal fellow eyes served as a control. When the normal fellow eye was covered and the patient was asked to watch the center of the pattern stimuli with the affected eye, the poor fixation often caused irregular eye movements which resulted in a poor reproducibility of the response. In such instance we opened the normal fellow eye for fixation, which helped to stabilize the affected eye being examined even when visual acuity was extremely poor. The cross-talk phenomenon of the ERG and the reflection of the VER from the normal fellow eye were proved negligible in this recording condition. We analyzed PERGs in comparison with the visual acuity and the degree of optic atrophy. Unlike the results of many previous authors, little correlation was observed between PERG and these two factors. Most patient showed normal or only slightly abnormal PERG, even when the visual acuity was extremely poor and the optic disc was completely atrophic. Our results suggest that, at least with our method, PERG has extremely limited value in detection of optic nerve disease.

Osteotomy was performed for cubitus varus deformity in 14 patients following supracondylar fracture of the humerus. In the first four patients the osteotomy was performed by a standard wedge technique and in the last ten cases by a new technique of hemiwedge osteotomy. The hemi-wedge technique permitted better control of the correction and better fixation of the osteotomy. Before the operation all cases had a cubitus varus of 10° or more. After the operation all but one patient had a normal carrying angle or at most a cubitus varus of 5°. In this case the standard osteotomy failed because of poor fixation and after re-operation by the hemi-wedge osteotomy because of infection.

Total hip replacement for adults with unreduced congenital dislocation presents a difficult problem because soft-tissue contractures usually prevent sitting at the normal anatomical level. Extensive soft-tissue division or a high-level acetabulum leads to reduced function and poor fixation of the components. We describe a new technique for hip replacement in such cases. The shortened abductors and flexors are released proximally and excision of the upper third of the ilium allows them to be repaired without tension, while providing bone graft to reconstruct the acetabular roof. We report 12 such replacements in 10 patients with good results and few early complications.

1. The boldness with which we accepted Rush pin fixation was not justified, and our period of external immobilization was too short -this will need to be extended. 2. A prebent Rush pin inserted in or near Lister's tubercle and adequate immobilization is an acceptable treatment for fractures of the radius. 3. A Rush pin is probably inadequate fixation for fractures of the ulna, because of poor fixation for rotatory stress. A slotted plate, or possibly a triangular or a diamond nail, appears to be preferable for internal fixation of the ulna. 4. The judicious use of primary iliac grafts and early bone-grafting in delayed union will improve the end results.

Report on a family of 14 in which the mother and her first four children, born out of wedlock and having different fathers, had healthy eyes and no ocular troubles. Her husband, the father of the eight younger children, presented with concomitant strabismus and amblyopia in the left eye. All his children squinted also, and all but one had amblyopia and poor fixation in the affected eye.

Conventional nail plates provide a relatively poor fixation of unstable and pathological fractures of the upper femur, and nail-plate failure is not uncommon. A two-part device, the Kuntscher Y nail, provides a strong fixation in these cases and is not difficult to insert if the method described is employed. The results in 91 patients treated with the Y nail are discussed. Since distal migration of the nail has been prevented by use of a flanged medullary nail, no mechanical failure has occurred. Early weight bearing can be permitted after operation.

Circumscribed pink areas 0.3–1.0 cm in diameter seen in the deeper parts of otherwise well-fixed brains are usually ascribed to inadequate fixation. Twenty-three patients with pink areas in their fixed brains had evidence of inflammation in at least one organ. Blood vessels in the pink areas contained bacteria. Postmortem cultures identified the organisms in 16 cases. Gram-negative bacteria were the most common. Sharply delineated pink areas in well-fixed brains correlate with postmortem intravascular growth of bacteria.

In perfusion fixation, we have preferred gravity flow rather than a peristaltic forced flow because the latter may cause rupture of small blood vessels. One difficulty encountered in the gravity flow method is detection of flow stoppage, often caused by the formation of a blood clot. If this is apparent soon enough, steps can be taken to re-establish the flow, Flow stoppage is not usually detected for several minutes—resulting in poor fixation of the organ involved. To allow immediate detection of stoppage, a glass flow indicator (figure 1) was manufactured

OF all the abdominal organs, the spleen is most likely to burst after blunt trauma. Its thin capsule, proximity to the unyielding ribs and poor fixation make this likely. In the absence of shock or...