Electromagnetic Navigated Versus Conventional Total Knee Arthroplasty-A Five-Year Follow-Up of a Single-Blind Randomized Control Trial

BACKGROUND

The objective of this study is to provide the 5-year follow-up results of a randomized study comparing conventional versus electromagnetic computer navigated total knee arthroplasty.

METHODS

Analysis of 127 patients (66 navigated and 61 conventional surgeries) was performed from a prospective, single-blinded, randomized controlled trial. Patient-reported outcome measures were collected at 5 years after surgery and compared with previously published 1-year clinical outcomes. Five-year surgical revision rates were collated and compared between intervention groups.

RESULTS

Overall, there have been continued improvements in the clinical scores of patients in both groups when compared with clinical data at 1 year; however, at 5 years, there is no statistical difference in any of the patient-reported outcome measures between conventional and navigated surgery. Interestingly, improved implant survivorship was observed in the navigated (0% revision rate) compared with the conventional group (4.9% all-cause revision rate).

CONCLUSION

Electromagnetic computer navigated technology produces similar clinical outcomes compared with traditional surgery. Further work is required to monitor implant survivorship, and clinical outcomes with long-term follow-up, to determine the cost effectiveness of this technology.

Predictive ability of preinjury stressful life events and post-traumatic stress symptoms for outcomes following mild traumatic brain injury: analysis in a prospective emergency room sample

BACKGROUND

A subset of persons with mild traumatic brain injury (mTBI) experience long-term difficulties. Preinjury stress has been hypothesised to play a role in long-term maintenance of symptoms.

OBJECTIVE

To investigate the predictive ability of preinjury stressful life events and post-traumatic stress symptoms to health-related quality of life and emotional distress after mTBI.

METHODS

Within 2 weeks of injury, 186 participants with mTBI who were admitted to an emergency centre completed an interview and questionnaires regarding preinjury functioning, including the Stressful Life Events Questionnaire and the Post-Traumatic Stress Disorder Checklist. Outcomes were assessed at 3 months after injury and included the depression and anxiety subscales of the Brief Symptom Inventory, and the physical and mental component scores of the 36-item Short-Form Health Survey (SF-36). The incidence and type of stressful life events were reported. Hierarchical regression analyses were used to determine the predictive utility of Stressful Life Events Questionnaire and Post-Traumatic Stress Disorder Checklist after controlling for age, injury severity (complicated versus uncomplicated mild) and preinjury depression.

RESULTS

Several potentially life-altering stressful events were endorsed by at least 25% of participants as having been experienced prior to injury. The incidence of stressful life events was a significant predictor of all four outcome variables. History of post-traumatic stress symptoms was predictive of scores on the SF-36 mental health component.

CONCLUSIONS

A history of stressful events may predispose persons with mTBI to have poor outcomes. History of stress should be assessed during the early stages after mTBI to help identify those who could benefit from therapies to assist with adjustment and maximise recovery.

Contractile properties of muscle fibers from the deep and superficial digital flexors of horses

Equine digital flexor muscles have independent tendons but a nearly identical mechanical relationship to the main joint they act upon. Yet these muscles have remarkable diversity in architecture, ranging from long, unipennate fibers ("short" compartment of DDF) to very short, multipennate fibers (SDF). To investigate the functional relevance of the form of the digital flexor muscles, fiber contractile properties were analyzed in the context of architecture differences and in vivo function during locomotion. Myosin heavy chain (MHC) isoform fiber type was studied, and in vitro motility assays were used to measure actin filament sliding velocity (V(f)). Skinned fiber contractile properties [isometric tension (P(0)/CSA), velocity of unloaded shortening (V(US)), and force-Ca(2+) relationships] at both 10 and 30°C were characterized. Contractile properties were correlated with MHC isoform and their respective V(f). The DDF contained a higher percentage of MHC-2A fibers with myosin (heavy meromyosin) and V(f) that was twofold faster than SDF. At 30°C, P(0)/CSA was higher for DDF (103.5 ± 8.75 mN/mm(2)) than SDF fibers (81.8 ± 7.71 mN/mm(2)). Similarly, V(US) (pCa 5, 30°C) was faster for DDF (2.43 ± 0.53 FL/s) than SDF fibers (1.20 ± 0.22 FL/s). Active isometric tension increased with increasing Ca(2+) concentration, with maximal Ca(2+) activation at pCa 5 at each temperature in fibers from each muscle. In general, the collective properties of DDF and SDF were consistent with fiber MHC isoform composition, muscle architecture, and the respective functional roles of the two muscles in locomotion.

The present role of nuclear cardiology in clinical practice

Many advances have been made in the field of nuclear cardiology in the past decade for enhancing the diagnostic and prognostic value of stress myocardial perfusion imaging and the assessment of myocardial viability using SPECT technology. Gated SPECT for determining regional and global function have provided incremental diagnostic and prognostic information in the evaluation of patients with suspected or known coronary artery disease. Left ventricular ejection fraction and regional myocardial wall thickening can now be simultaneously evaluated with regional perfusion particularly with the use of the (99m)Tc-labeled perfusion agents such as sestamibi and tetrofosmin. Many studies have shown that the extent and severity of stress-induced perfusion defects have incremental prognostic value over exercise electrocardiographic stress test variables alone. Patients with normal perfusion scans have <1% combined cardiac death and myocardial infarction rates per year and thus have an excellent prognosis. Diabetics are particularly benefited from stress perfusion imaging for detection of coronary artery disease and risk assessment. Diabetics have a worse prognosis than nondiabetics for the same amount of hypoperfusion on stress SPECT studies. Quantitative rest perfusion imaging with (201)Tl or with one of the (99m)Tc-labeled imaging agents, or PET imaging with (18)F-deoxyglucose can accurately distinguish viable from irreversibly injured myocardium providing useful information for identifying which patients with ischemic cardiomyopathy benefit most from coronary revascularization with a subsequent improvement in left ventricular function and enhanced survival. Finally, serial stress perfusion imaging can be employed to monitor the efficacy of medical therapy that improves endothelial function and myocardial blood flow reserve.

Cognitive and neurobehavioral functioning after mild versus moderate traumatic brain injury in older adults

This study evaluated the early cognitive and neurobehavioral outcomes of older adults with mild versus moderate traumatic brain injury (TBI). Thirty-five patients who were age 50 years and older and sustained mild or moderate TBI were prospectively recruited from acute care hospitals. Patients were administered cognitive and neurobehavioral measures up to 2 months post-injury. Demographically comparable control participants received the same measures. Patients and controls did not have previous histories of substance abuse, neuropsychiatric disturbance, dementia, or neurologic illness. Moderate TBI patients performed significantly poorer than mild TBI patients and controls on most cognitive measures, whereas the mild patients performed comparably to controls. In contrast, both mild and moderate patients exhibited significantly greater depression and anxiety/somatic concern than controls. The results indicate that the classification of TBI as mild versus moderate is prognostically meaningful as applied to older adults. The findings extend previous investigations in young adults by demonstrating a relatively good cognitive outcome on objective measures, but subjective complaints after a single, uncomplicated mild TBI in older persons.

Cognitive and behavioral sequelae of closed head injury in older adults according to their significant others

This study examined the neurobehavioral effects of closed head injury (CHI) in older adults according to their significant others. Informants of 17 mild and moderate CHI patients > or = 50 years old when injured completed the Geriatric Evaluation of Relative's Rating Instrument, a questionnaire inquiring about the patient's cognition, affect, interpersonal relations, and daily activities. The significant others provided retrospective ratings of preinjury functioning and completed the same instrument an average of 4 and 13 months post-injury. The significant others of 10 community-residing, normal control subjects completed the questionnaire at comparable intervals between each rating. Compared with their preinjury functioning, and unlike the control subjects, patients showed declines in cognition and mood. The possible impact of these changes, including their effect on subjective burden in caregivers, is discussed.

Short-form alternatives to the Judgment of Line Orientation Test

The Judgment of Line Orientation Test (JLO; Benton, Hamsher, Varney, & Spreen, 1983) is frequently used as a motor-free method of evaluating visuospatial processing but can be time-consuming to administer. We investigated the internal consistency, validity, and utility of two parallel JLO short forms in a mixed clinical sample of 386 patients. Mean scores were equivalent, and correlational analyses supported the internal consistency and validity of both short forms. When compared to the standard JLO, the odd- and even-item short forms demonstrated good sensitivity, specificity, overall hit rate and predicted positive and negative accuracy. We conclude that the JLO short forms possess sufficient internal consistency, validity, and utility for serial assessment in research studies. The JLO short forms may potentially be used in clinical screening situations by applying a single cut-off score to differentiate levels of performance. However, more detailed clinical use of these JLO short forms will necessitate collection of normative data in order to generate accurate percentile rankings.

PR interval in the aged

The length of the PR interval in 691 geriatric in-patients was examined for significant relationships in respects of age, sex and abnormality of the recording. No significant difference between sex and abnormality was found. Abnormal tracings were associated with longer PR intervals in both sexes, being most marked in men. Men showed longer PR intervals than women especially when the record was abnormal. No evidence of an age-related lengthening of the PR interval was found but there was a sudden increase between 75 and 80 years of age. PR intervals of less than 0.12 s were found in 3.8%, and 2.7% had intervals of more than 0.22 s. Short PR intervals of the Lown-Ganong-Levine type are not uncommon in old age. Lengthening of the PR interval in the normal range appears to be related to acquired and disease factors and is not due to a gradual ageing process.

Euthyroid "thyroxine toxicosis"

A survey was made of thyroid function tests on 1,153 patients screened for thyroid disease during a two-year period in a Geriatric Department; 13 percent of the test results fell outside the normal range. Of 88 patients who showed above-normal results, only 12 presented with clinical features of thyrotoxicosis. In 37 patients, the biochemical findings indicated euthyroid "thyroxine toxicosis"; high values were found for serum thyroxine (T4) and the free thyroxine index (FT4I) but there were no clinical signs or symptoms of thyrotoxicosis; the values reverted to normal within one to three weeks. This pattern was seen also in 7 examples of T4-treated hypothyroidism. (Overall, the test findings indicated 61 cases of hypothyroidism.) The significance of this transient increase in T4 and FT4I values is discussed. The false positive results suggest that, when laboratory findings are not compatible with the clinical signs, the thyroid function tests should be repeated after another two weeks.

d-Amphetamine in elderly patients refractory to rehabilitation procedures

This report concerns the use of d-amphetamine in 88 elderly inpatients who initially failed to respond to rehabilitation procedures. These patients exhibited characteristics of the Poor Motivation Syndrome (PMS), not associated with depression or dementia. The syndrome was seen five times more frequently in women. d-Amphetamine was given for three weeks in increasing dosage (2.5--10.0 mg twice daily). The responses were scored according to mobility, self-care and motivation. Of the 88 patients, 48 improved and another 28 were discharged who would otherwise have remained dependent nursing cases. An unexpected finding was that 17 patients showed an age-related resistance to the effects of the drug (P less than 0.05). The likelihood of a beneficial response also diminished with increasing age (P less than 0.01). Side effects were in the psychiatric sphere; they occurred in 23 patients early in treatment and were not age-related; the drug was withdrawn. Thus treatment with d-amphetamine should be restricted to selected patients who satisfy the diagnostic criteria of PMS, and administration should be carefully supervised. With these safeguards, a substantial proportion of patients previously refractory to rehabilitation will show improvement, become more independent and may be discharged from the hospital in a much more active, less dependent state of mine and body.

Atrial fibrillation complicating Wolff-Parkinson-White syndrome treated with amiodarone

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Klinefelter syndrome in the aged

Three cases of Klinefelter syndrome diagnosed late in life are reported with the clinical and post-mortem findings. The diagnosis was suspected owing to the absence of testes and the presence of associated varied clinical features. The urinary follicle-stimulating hormone levels were not elevated and were very low in two of the cases. Bronchopneumonia, ascending pyelonephritis and cystitis were the main causes of death but there were varied pathological findings in the prostate of benign hyperplasia, carcinoma and prepubertal gland. Marked atherosclerosis of the aorta and the lower-limb vessels were present but the coronary systems were little affected. It is suggested that, because of the presence of two X chromosomes and the absence of testes, this condition may give a female pattern of longevity, many examples being overlooked in old age on account of inadequate clinical examination. Some support for this hypothesis will be found if its incidence in the aged is shown to be greater than in the young.

Multifocal atrial tachycardia (MAT). The misdiagnosed atrial arrhythmia of old age

The clinical and electrocardiographic features of multifocal atrial tachycardia are described and illustrated by nine examples. It is almost entirely seen in later life and is often misdiagnosed as atrial fibrillation. It is associated with a high mortality and the majority of the cases described here reverted to sinus rhythm. Little attention has been so far paid to this important arrhythmia in the elderly in standard textbooks of cardiology. The literature is reviewed and management discussed. It is not a rare supreventricular tachycardia in the aged and many examples may be not diagnosed. It merits further study in relation to unanswered questions.

Wheat bran in dyschezia in the aged

A trial of wheat bran added to the diet of aged dyschezic hospital patients (12 men, 13 women) is reported. This significantly reduced the need for aperients and suppositories but revealed unexpected differences in response by sex. In men, bran produced more bowel actions, fewer constipated days and an increase in stool size. In women there was much less effect upon the number of bowel actions and reduction of constipated days. In men there were fewer constipated days and need for aperients after the bran was withdrawn. Side-effects were only seen in men. Most patients received 15 g/day (range 5-25 g/day). Although cheap and effective in replacing aperients, there were problems in administration and control of incontinence for the nursing staff. The value of added wheat bran in the bowel management of the long-stay hospital patient is discussed and an effective method of combining bran in the diet (e.g. with bread) might be further investigated.

Cardiac effects of carotid sinus massage in old age

The effects of carotid sinus massage in aged subjects with a high incidence of arteriosclerosis are described. In 71 men and 315 women tested, a slowing of more than 10 per cent of the heart rate was found in 25 per cent of the men and 19 per cent of the women, which is not of statistical significance in relation to sex. Only men showed a significant increase with age and the women had a significant preponderance of a right-sided response. The technique was found to be safe, although a review of reported side-effects suggests care is advisable and carotid compression must not occur. The findings are discussed in relation to those reported in younger subjects and in carotid sinus syndrome with syncope. The fact that men have an acquired increase in response in old age, which is not seen in women, may be a factor of importance in the explanation of why carotid sinus syncope is almost always seen in men. Carotid sinus sensitivity appears to diminish in old age and some of the ageing factors which might influence the carotid sinus reflex are examined.

Diogenes syndrome. A clinical study of gross neglect in old age

A study of elderly patients (fourteen men, sixteen women) who were admitted to hospital with acute illness and extreme self-neglect revealed common features which might be called Diogenes syndrome. All had dirty, untidy homes and a filthy personal appearance about which they showed no shame. Hoarding of rubbish (syllogomania) was sometimes seen. All except two lived alone, but poverty and poor housing standards were not a serious problem. All were known to the social-services departments and a third had persistently refused offers of help. An acute presentation with falls or collapse was common, and several physical diagnoses could be made. Multiple deficiency states were found--including iron, folate, vitamin B12, vitamin C, calcium and vitamin D, serum proteins and albumin, water, and potassium. The mortality, especially for women, was high (46%); most of the survivors responded well and were discharged. Half showed no evidence of psychiatric disorder and possessed higher than average intelligence. Many had led successful professional and business lives, with good family backgrounds and upbringing. Personality characteristics showed them to tend to be aloff, suspicious, emotionally labile, aggressive, group-dependent, and reality-distorting individuals. It is suggested that this syndrome may be a reaction late in life to stress in a certain type of personality.