Plastic physicians: The surgical salamanders of the COVID-19 pandemic.

At the time of writing, coronavirus disease-2019 (COVID-19) has affected 6.42 million people globally and over 380,000 deaths, with the United Kingdom now having the highest death rate in Europe. The plastic surgery department at Leeds Teaching Hospitals put necessary steps in place to maintain an excellent urgent elective and acute service whilst also managing COVID-positive medical patients in the ward. We describe the structures and pathways implemented together with complex decision-making, which has allowed us to respond early and effectively. We hope these lessons will prove a useful tool as we look to open conversations around the recovery of normal activity.

Postoperative staphylococcal toxic shock syndrome due to pre-existing staphylococcal infection: case report and review of the literature.

Staphylococcal postoperative toxic shock syndrome (PTSS) has been associated with a variety of surgical procedures. It is generally believed that the source of infection is acquired at or near the time of surgery. PTSS has been specifically associated with nasal packing, insertion of hardware, surgical drains, retained foreign materials, and breaks in sterile technique. Although PTSS has been associated with postoperative abscesses, development of PTSS after surgery of a pre-existing source of infection has not been described. We report a case of PTSS that developed after vertebral abscess drainage, and we review the literature to determine the incidence of PTSS due to preexisting staphylococcal infection.

A clinical review of the orthotic treatment of myelomeningocele patients.

High myelomeningocele lesions do not preclude an acceptable level of functional walking provided that an integrated programme of surgical treatment and bracing is adopted. Clinical analysis of 100 patients with myelomeningocele shows that the development of the "swivel walker" and "hip guidance orthosis" has been associated with an improved level of function. Over 30 per cent of patients with thoracic lesions and 68 per cent of those with lumbar lesions achieved independent walking. For this reason the criteria used at present by paediatricians to govern the selection of infants for non-active treatment may require reconsideration.

Estimation of deformation in a walking orthosis for paraplegic patients.

Although good results have already been achieved in reciprocal walking for paraplegic patients using mechanical orthoses (e.g. ORLAU ParaWalker), improvements in lateral stiffness of walking devices could increase significantly the efficiency of ambulation. For this reason a method for monitoring the structural properties of an orthosis during locomotion has been studied. A motion analysis system (ELITE system) able to detect automatically and accurately the positions of small retroreflective markers in a television field was used. Starting from marker positions, the angular variations between adjacent structural segments in the orthosis were computed and the areas in which maximum deformations occurred were identified. Experiments were performed on two paraplegic patients using their ORLAU ParaWalker orthoses and two different kinds of movements were analysed: lateral tilting and walking. The results show that this approach is able to detect the small deformations occurring in the orthotic structure and therefore to provide valuable information for orthotic design optimization.

Performance specification for lower limb orthotic devices.

OBJECTIVE: To establish the range of forces and moments applied to lower limb orthoses during ambulation by routine users. DESIGN: Well-established gait analysis techniques were used to determine the loading at the major joints. It was assumed that the joint moments were transmitted by the orthosis encompassing any particular joint. Two hundred and five assessments of 164 patients were successfully completed by a consortium of four gait laboratories in Europe. The orthosis specification and patient clinical data were also recorded. BACKGROUND: The design and development of orthoses has occurred largely by evolution rather than by formal engineering methods. In particular, formal design has been hampered by a lack of information on the forces and moments applied during ambulation. METHODS: A standard gait analysis procedure was employed to capture the data. In-house biomechanical models were used to calculate the joint loading. Data were normalised with respect to patient weight and leg length. RESULTS: It was found that the median maximum normalised ankle moment transmitted by an ankle foot orthosis was 0.15 and the maximum knee moment was 0.09. The greatest moment transmitted by the hip joint of a hip knee ankle foot orthosis was also 0.09. There was a wide variation in the data due to differences in the impairments of the test subjects. CONCLUSION: It is possible to estimate the loads transmitted by an orthosis using established gait analysis procedures without the need for load measurement transducers. There is now a need both to collect a larger representative dataset and to perform validation studies with transducers.

Transportable two-dimensional gait assessment: routine service experience for orthotic provision.

PURPOSE: The purpose of the pilot service was to establish the potential of the newly developed system to achieve, in a community setting, more effective orthotic outcomes for patients in whom alignment of ground reaction force is an important treatment objective. METHODS: Twelve visits were arranged to a paediatric community physiotherapy department. Up to six patients at each visit were selected for assessment of their lower limb orthotic prescription. The patient's gait was assessed using the video vector generator to determine alignment of ground reaction force. Where necessary, adjustments to the orthotic set-up were made to achieve more closely the stated objective. At the conclusion a specification of the orthosis was agreed. RESULTS: In only two of 61 assessments that were conducted was it not possible to achieve a useful outcome. CONCLUSIONS: Improvements in biomechanical alignment were achieved in more than 68% of assessments. The pilot service was sufficiently successful for it to be extended to a routine clinical service.

A long-term review of severely disabled spina bifida patients using a reciprocal walking system.

PURPOSE: The purpose of the study was to establish long-term compliance of paediatric spina bifida patients using a reciprocal walking orthosis, prescribed to enhance function and long-term therapeutic benefit. METHODS: Data from current clinical notes of 28 spina bifida patients prescribed with the Parawalker reciprocal walking orthosis between 1973 and 1984 were compared with those established for the purposes of research at the time of original prescription. Patients were supplied via an on-going treatment regime by a specialist multi-disciplinary team. Regular follow-up was an essential element of the clinical policy. This enabled effective monitoring of patient performance and requirements. It also ensured that accurate data was maintained. Clinical and walking performance details were recorded at the time of supply. Current clinical notes from routine follow-up reviews for patients in the study were scrutinized to establish present status, ambulation performance and medical history. RESULTS: Fourteen patients had thoracic lesions the remainder having high, mid lumbar or variably diagnosed lesions. The period of use ranged from 4.6 to 18.1 years (average = 9.71 years) The orthosis was first prescribed at 3.6 years to 13.9 years. Discontinuation occurred at between 11.2 and 23.9 years. None of the patients suffered a pressure sore or bone fracture. CONCLUSIONS: Long-term continuation of reciprocal walking within a controlled treatment regime was established. This enabled confirmation that comprehensive health care systems can achieve improvements in patient function, together with overall cost savings because of the reductions in pressure sores and bone fractures identified for such activity.

The use of the Orthotic Research and Locomotor Assessment Unit (ORLAU) ParaWalker by adult myelomeningocele patients: a seven year retrospective study--preliminary results.

There is a widely accepted perception that whereas many paediatric myelomeningocele patients use walking orthoses effectively, very few continue to ambulate in adult life. A seven-year retrospective review of 31 patients for whom the ORLAU ParaWalker (2) was prescribed in Oswestry showed that there was a 58% adult compliance rate. Of the 18 who continued walking the average age at supply was 11.28 years (range 5 to 24), average age at survey 22.61 yrs. (range 17 to 33) and the average period of use was 11.33 yrs. (range 3 to 16). These results compare surprisingly well with an ORLAU review of adult traumatic lesions who had a compliance rate of 63% and average follow-up of 2.87 years. The ORLAU ParaWalker has been shown to be an efficient form of walking and this is considered an important feature in ensuring that many adults can continue to take advantage of the proven therapeutic benefits of walking. Notwithstanding, the adult compliance rate shown in this study lends strength to the case for a vigorous and efficient walking programme in treating spina bifida children so as to promote the longer term health of the patient.

[Effect of nifedipine on arterial pressure and control of the cardiac reflex]. / Effet de la nifédipine sur la pression artérielle et le contrôle cardiaque réflexe.

Nine patients with untreated essential hypertension (random blood pressure 173/109 +/- 14/7 mmHg) were studied before and after 16 weeks' treatment with oral nifedipine 10 mg three times a day. Direct continuous measurement of the systolic and diastolic blood pressures showed that both values were significantly reduced during the 24 hour period. Nifedipine did not change the variability of the blood pressure. There was no significant change in the heart rate after treatment with nifedipine. Long-term nifedipine induced an increase in blood flow in the forearm and decreased the vascular resistances which confirmed the vasodilator effects of the drug. The absolute responses of the blood pressure during postural changes, the hand grip test and cold pressor test were reduced but the treatment did not change the percentage increase in blood pressure during these tests. Long-term nifedipine therapy did not affect the plasma renin activity. The sensitivity and characteristics of the baroreflex response to intravenous phenylephrine were measured. After long-term nifedipine therapy we observed a normalisation of the sino-aortic baroreflex and an increase in its sensitivity. Normalisation of the blood pressure by nifedipine induced a significant reduction in the index of left ventricular mass.

The case for lateral stiffness in walking orthoses for paraplegic patients.

The provision of walking for paraplegic patients has therapeutic benefits but must be at a low energy cost. Although claims have been made regarding the need for high lateral stiffness in any orthosis targeted at this group, much of the supporting evidence was confusing. This paper presents the theoretical reasoning behind this claim and reviews recent evidence that would appear to support it.

Reciprocal walking orthosis with composite material body brace: initial development.

Reciprocal walking orthoses are routinely used by thoracic lesion patients for ambulation using crutches. A primary reason for their prescription is to provide therapeutic benefit and improved independence. To achieve this, maximum efficiency of walking and acceptance of the device is necessary to promote long-term compliance. Lateral rigidity in the orthosis influences walking efficiency, but the structural properties of conventional techniques for producing a sufficiently rigid body brace makes them unattractive. Currently patients and clinicians are forced to choose between greater efficiency or cosmesis of the orthosis. Composite materials have the potential to permit the required rigidity in a structure that is less obtrusive. However, their material properties could lead to unsafe forms of failure unless suitable manufacturing methods are devised. It is therefore inappropriate to supply prototypes to patients for field evaluation until laboratory investigation of innovative production methods has ensured that the orthosis is safe. A production technique has been devised that is ostensibly suitable. Prototype body braces have been tested and have been shown to have improved structural properties and safe failure modes. A test programme implemented on a complete concept orthosis has confirmed that improved lateral rigidity can be achieved with a less obtrusive body brace, and that it will behave safely for long enough to permit field evaluation.

Structural design and performance of a rear support walking frame.

Rear support walking frames provide predetermined vertical support for patients with dysfunctional lower limbs that have limited active control; the support is provided through a spring-loaded boom hinged on an upright stanchion mounted at the rear of a wheeled frame within which the patient ambulates. The application of these frames for total-body-involved cerebral palsy patients, in combination with a walking orthosis, has highlighted a number of practical problems that need to be addressed for the system to become fully viable. A composite material prototype walking frame has been developed that permits the patient to be transferred by a single carer without the need to use inappropriate manual handling techniques. The frame has improved structural properties, with stiffness in the sagittal and coronal planes increasing by between 50 and 100 per cent. Evaluation with patients showed that the greater structural stiffness permitted the objective of improved continuity of walking to be achieved. The strength of the frame is such that it can accommodate patients of up to 80 kg, more than twice that possible in the earlier system. Since the structural yield point is approximately twice the maximum working load, the device should not be prone to unacceptable fatigue characteristics. Despite the use of carbon composite materials (which have brittle failure characteristics), the mode of failure is of progressive collapse and is therefore inherently safe. The successful outcome of prototype testing has justified production development. Work is now proceeding on a design that incorporates further improvements in structural performance and ease of manufacture.

Feasibility study on a composite material construction technique for highly stressed components in reciprocal walking orthoses for paraplegic patients.

Reciprocal walking for thoracic level paraplegic patients using reciprocal walking orthoses has become a routine treatment option. Two general design options are currently deployed within an overall treatment regime. Research has shown that one has better walking efficiency but is cosmetically less acceptable to the patient. Design analysis and experimental data have shown that a major factor in improved walking efficiency is the lateral stiffness of the body brace section of the orthosis. This is the area where problems of cosmesis in the more efficient orthosis are perceived because of the employment of metallic structures. The use of composite material structures to achieve shapes which are more closely conforming to the patient is an attractive option. However the brittle nature of these materials makes it unlikely that the requirement for the ductile failure mode will be achieved from a straightforward moulding. A new construction technique has been devised which has the potential to provide a safe failure mode with greater stiffness and lighter weight. This feasibility study has been undertaken to demonstrate its potential so that further work can be justified which will provide sufficient evidence to support a patent application. The successful outcome of the study, in which stiffness was increased by 60 per cent with a weight reduction of 50 per cent and a failure mode comparable with the original metal structure, suggests that further work will enable the dilemma in the choice of orthosis to be resolved.

An infant reciprocal walking orthosis: engineering development.

The growing trend of prescription of reciprocal walking orthoses for children under the age of 5 years has created a requirement for a new design of orthosis in this category. In response to this new demand, a prototype orthosis for infants, incorporating a specially developed hip joint and manufactured as a rehabilitation engineering device within the provisions of the EC Medical Devices Directive, has been produced and tested. A design feature that strongly influences the efficiency of walking is the rigidity of the body brace structure. Monitoring the specific structural performance of the body brace intended for infants showed that it would equal or improve the stiffness achieved in an orthosis for adults. Additionally its strength was comparable with the adult design, which has proven to be safe and reliable in many years of routine prescription. Incorporation of the infant body brace within a complete orthosis provided a structure of more acceptable physical dimensions for these more diminutive patients. The orthosis showed no incipient sign of failure after 100,000 cycles of representative service loading equivalent to that imposed by a 20 kg (5-year-old) patient. The results of structural assessment and cyclic load testing confirm that the design of the orthosis sufficiently satisfies the statutory requirements for devices that are safe and fit for purpose to permit field trials with patients.

Sludge digestion enhancement and nutrient removal from anaerobic supernatant by Mg(OH)2 application.

Anaerobic sludge digestion is a widely adopted process for sludge stabilization. Phosphate removal from anaerobic supernatant is necessary to limit the phosphate returned to the head of the treatment plant, thereby improving the overall treatment efficiency. In this study, magnesium hydroxide (Mg(OH)2) was used to improve the sludge digestion efficiency and to remove phosphorus from anaerobic supernatant. The anaerobic sludge digestion experiment was conducted at a pilot scale, and the results showed that applying Mg(OH)2 to anaerobic sludge digester resulted in a larger reduction in SS and COD, a higher biogas production rate, a lower level of phosphate and ammonia nitrogen concentrations in the sludge supernatant and an improved sludge dewaterability. Research results at both lab scale and pilot scale on phosphorus removal from anaerobic supernatant using Mg(OH)2 showed that a high removal of phosphorus can be achieved through the addition of Mg(OH)2. The required reaction time depends on the initial phosphorus concentration and the Mg(OH)2 dosage.

Assessment of orthoses by means of speed and heart rate.

Energy expenditure is an important parameter in the assessment of gait and orthotic treatment of heavily handicapped patients, since any orthosis which increases the effort required is likely to be discarded with consequently disturbing implications. Heart rate has been shown to be a reliable monitor of energy expenditure and is convenient because ECG can be telemetered by a miniature radio transmitter. Using a transmitter causes minimal interference with the patient, but care must be employed to obtain ECG signals free of artefact from subjects who are exercising. Means of reducing artefact are discussed, as are ways in which heart rate monitoring by radio telemetry is being used in the routine assessment of orthotic treatment of paediatric patients and the development of new orthotic devices.