Transmission dynamics and associated mortality of nosocomial COVID-19 throughout 2021: a retrospective study at a large teaching hospital in London.

BACKGROUND: The impact of nosocomial SARS-CoV-2 infections has changed significantly since 2020. However, there is a lack of up-to-date evidence of the epidemiology of these infections which is essential in order to appropriately guide infection control policy. AIMS: To identify the secondary attack rate of SARS-CoV-2 infection and associated mortality across different variants of concern. METHODS: A single-centre retrospective study of all nosocomial SARS-CoV-2 exposure events was conducted between 31st December 2020 and 31st December 2021. A secondary attack rate was calculated for nosocomial acquisition of SARS-CoV-2 infection and time to positivity. Positive contacts were assessed for all-cause 30-day mortality. RESULTS: A total of 346 sequential index exposure events were examined, and 1378 susceptible contacts identified. Two hundred susceptible contacts developed SARS-CoV-2 infection (secondary attack rate of 15.5%). The majority of index cases (59%) did not result in any secondary SARS-CoV-2 infection. Where close contacts developed SARS-CoV-2 infection, 80% were detected within the first five days since last contact with the index case. The overall associated mortality among positive contacts across 2021 was 9%, with an estimated reduction of 68% when comparing periods of high Omicron versus Alpha transmission. CONCLUSION: Our findings describe that most SARS-CoV-2 infections are detected within five days of contact with an index case; we have also demonstrated a considerably lower mortality rate with the Omicron variant in comparison to previous variants. These findings have important implications for informing and supporting infection control protocols to allow movement through the hospital, and ensure patients access care safely.

Positioning accuracy for lung stereotactic body radiotherapy patients determined by on-treatment cone-beam CT imaging.

Stereotactic body radiotherapy for early stage non-small cell lung cancer is an emerging treatment option in the UK. Since relatively few high-dose ablative fractions are delivered to a small target volume, the consequences of a geometric miss are potentially severe. This paper presents the results of treatment delivery set-up data collected using Elekta Synergy (Elekta, Crawley, UK) cone-beam CT imaging for 17 patients immobilised using the Bodyfix system (Medical Intelligence, Schwabmuenchen, Germany). Images were acquired on the linear accelerator at initial patient treatment set-up, following any position correction adjustments, and post-treatment. These were matched to the localisation CT scan using the Elekta XVI software. In total, 71 fractions were analysed for patient set-up errors. The mean vector error at initial set-up was calculated as 5.3 ± 2.7 mm, which was significantly reduced to 1.4 ± 0.7 mm following image guided correction. Post-treatment the corresponding value was 2.1 ± 1.2 mm. The use of the Bodyfix abdominal compression plate on 5 patients to reduce the range of tumour excursion during respiration produced mean longitudinal set-up corrections of -4.4 ± 4.5 mm compared with -0.7 ± 2.6 mm without compression for the remaining 12 patients. The use of abdominal compression led to a greater variation in set-up errors and a shift in the mean value.

Dosimetric evaluation of a conformal seven-field coplanar technique for planning lung stereotactic body radiotherapy.

AIMS: To assess the effectiveness of a seven-field coplanar planning technique in producing dosimetrically acceptable treatment plans when measured against the dose constraints of the ROSEL trial quality assurance working party. MATERIALS AND METHODS: Nineteen patients with non-small cell lung cancer staged at T1-T2 underwent computed tomography scanning in preparation for lung stereotactic body radiotherapy treatment. Planning target volumes ranged from 17 to 100 cm(3). Dose plans were created with the enhanced collapsed cone algorithm on the Oncentra Masterplan treatment planning system using an open-field conformal coplanar technique. The plan acceptance criteria in the ROSEL study protocol were used for critical evaluation of the plans to determine their suitability for clinical use. RESULTS: Clinically acceptable plans were produced for 17 of the 19 patients with no more than two minor dosimetric deviations from protocol. The two patients where conflicts between adequate tumour coverage and unacceptably high doses to surrounding tissue could not be reconciled were characterised by low average Hounsfield Unit values in the planning target volume, i.e. less than about -700 Hounsfield Units. This tissue density was comparable with that of the surrounding healthy lung tissue. CONCLUSION: This planning technique produces clinically acceptable plans for most lung stereotactic body radiotherapy patients without the need to resort to more complex methods of treatment planning and delivery.

In vivo sagittal plane kinematics of the FPV patellofemoral replacement.

PURPOSE: Isolated symptomatic patellofemoral osteoarthritis has been reported in 2% of men and 8% of women older than the age of 55 years in the community. With the development of improved designs and surgical techniques, interest in the use of patellofemoral replacement has increased. The primary aim of the newer generation of patellofemoral replacement implant designs has been to more closely reproduce normal knee kinematics. This study compares the functional sagittal plane in vivo kinematics of a contemporary patellofemoral prosthesis, the FPV, with normal knee kinematics using the patella tendon angle and patella flexion angle relationships with the knee flexion angle. METHODS: The in vivo kinematics for a group of 8 patients (15 knees) with patellofemoral replacement and 22 normal subjects was measured for both a step-up and a lunge exercise using an established fluoroscopic method. RESULTS: The patella tendon angle characteristics of the implanted knees were similar to those of the normal knees for the step-up exercise with a significant difference only observed at 50° knee flexion angle. For the lunge exercise, the patella tendon angle for the implanted knee was consistently lower than that measured for the normal knee. Overall the subjects had excellent clinical scores post-patellofemoral replacement showing a significant improvement from their pre-operative scores. CONCLUSION: The kinematics of the FPV implant was closer to normal than those of total knee implants; however, there were still differences from the normal knees. LEVEL OF EVIDENCE: III.

Recto-urethral fistula following brachytherapy for localized prostate cancer.

OBJECTIVE: The use of prostate brachytherapy (BT) in the management of prostate cancer is increasing. BT is often chosen because of its perceived lower toxicity when compared with other radical therapy options. Rarely however serious complications can occur. One such complication is recto-urethral fistula (RUF). We report the incidence of RUF following BT at our centre and review the potential factors in fistula development. METHOD: A prospectively collected database was used to identify cases of RUF among 1455 patients treated with prostate BT at a single UK centre with at least 2 years of follow up. This included patients treated with BT monotherapy, as well as those treated with BT combined with external beam radiotherapy and BT used as salvage as all these groups have a higher incidence of RUF. Implant dose and volume characteristics for those patients, their co-morbidities and history of endoscopic procedures were recorded. RESULTS: Recto-urethral fistula was identified in three (0.2%) patients, occurring at 19-27 months following BT. All these patients had BT monotherapy. All three patients had rectal symptoms after their BT and had been investigated with endoscopy and low rectal biopsy. Subsequent surgical management with faecal and/or urinary diversion was required. On review of patients' BT details, radiation dose and volume parameters were higher on the postprocedure CT calculations than had been suggested by the preimplant plan. No other predisposing risk factors for RUF were identified. CONCLUSION: The incidence of RUF in our population is low. RUF following BT has been associated with rectal biopsy in previous series and this is confirmed in our report. Gastrointestinal specialists should not perform biopsy of the anterior rectum in patients who have had BT unless there is a very high clinical suspicion of malignancy.

How effective are added constraints in improving TKR kinematics?

Newer designs of total knee arthroplasty (TKA), through the use of added degrees of constraint, attempt to provide a "guided motion" to restore more normal and predictable kinematics. Two such design philosophies are the posterior stabilised (PS) using a cam-post and the medial pivot (MP) concepts. Knee kinematics of 12 patients with a PS TKA, 13 subjects with a MP TKA and 10 normal subjects were compared. For kinematic assessment, patients underwent fluoroscopic assessment of the knee during a step-up exercise and deep knee bend. Fluoroscopic images were corrected for distortion and assessed using 3D model fitting to determine relative 3D motion, and a 2D method to measure the patellar tendon angle (PTA) as function of knee flexion. For the PS design the cam-post mechanism engaged between 70 degrees and 100 degrees flexion. Between extension and 50 degrees there was forward motion of the contact points. Beyond 60 degrees both condyles rolled moved posteriorly. The majority of the external rotation of the femur occurred between 50 degrees and 80 degrees . The PTA was lower than normal in extension and higher than normal in flexion. The MP exhibited no anterior movement throughout the rage of motion. The medial condyle moved minimally. The lateral contact point moved posteriorly from extension to flexion. The femur rotated externally throughout the range of flexion analysed. The PTA was similar to normal from extension to mid flexion and then higher than normal beyond to high flexion. The PS design fails to fully restrain paradoxical anterior movement and although the cam engages, it does not contribute significantly to overall rollback. The MP knee does not show significant anterior movement, the medial pivot concept appears to achieve near normal kinematics from extension to 50 degrees of knee flexion. However, the results show that at high flexion this design does not achieve normal knee kinematics.

Anti-spasticity agents for multiple sclerosis.

BACKGROUND: Spasticity is a common problem in MS patients causing pain, spasms, loss of function and difficulties in nursing care. A variety of oral and parenteral medications are available. OBJECTIVES: To assess the absolute and comparative efficacy and tolerability of anti-spasticity agents in multiple sclerosis (MS) patients. SEARCH STRATEGY: We searched the Cochrane MS Group trials register (June 2003), the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2, 2003), MEDLINE (January 1966 to June 2003), EMBASE (January 1988 to June 2003), bibliographies of relevant articles, personal communication, manual searches of relevant journals and information from drug companies. SELECTION CRITERIA: Double-blind, randomised controlled trials (either placebo-controlled or comparative studies) of at least seven days duration. DATA COLLECTION AND ANALYSIS: Two independent reviewers extracted data and the findings of the trials were summarised. Missing data were collected by correspondence with principal investigators. A meta-analysis was not performed due to the inadequacy of outcome measures and methodological problems with the studies reviewed. MAIN RESULTS: Twenty-six placebo-controlled studies (using baclofen, dantrolene, tizanidine, botulinum toxin, vigabatrin, prazepam, threonine and cannabinoids) and thirteen comparative studies met the selection criteria and were included in this review. Only fifteen of these studies used the Ashworth scale, of which only three of the eight placebo-controlled trials and none of the seven comparative studies showed a statistically significant difference between test drugs. Spasms, other symptoms and overall impressions were only assessed using unvalidated scores and results of functional assessments were inconclusive. REVIEWER'S CONCLUSIONS: The absolute and comparative efficacy and tolerability of anti-spasticity agents in multiple sclerosis is poorly documented and no recommendations can be made to guide prescribing. The rationale for treating features of the upper motor neurone syndrome must be better understood and sensitive, validated spasticity measures need to be developed.

Anti-spasticity agents for multiple sclerosis.

BACKGROUND: Spasticity is a common problem in MS patients causing pain, spasms, loss of function and difficulties in nursing care. A variety of oral and parenteral medications are available. OBJECTIVES: To assess the absolute and comparative efficacy and tolerability of anti-spasticity agents in multiple sclerosis (MS) patients. SEARCH STRATEGY: Randomised controlled trials (RCTs) of anti-spasticity agents were identified using MEDLINE, EMBASE, bibliographies of relevant articles, personal communication, manual searches of relevant journals and information from drug companies. SELECTION CRITERIA: Double-blind, randomised controlled trials (either placebo-controlled or comparative studies) of at least seven days duration. DATA COLLECTION AND ANALYSIS: Two independent reviewers extracted data and the findings of the trials were summarised. Missing data were collected by correspondence with principal investigators. A meta-analysis was not performed due to the inadequacy of outcome measures and methodological problems with the studies reviewed. MAIN RESULTS: Twenty-three placebo-controlled studies (using baclofen, dantrolene, tizanidine, botulinum toxin, vigabatrin, prazepam and threonine) and thirteen comparative studies met the selection criteria. Only thirteen of these studies used the Ashworth scale, of which only three of the six placebo-controlled trials and none of the seven comparative studies showed a statistically significant difference between test drugs. Spasms, other symptoms and overall impressions were only assessed using unvalidated scores and results of functional assessments were inconclusive. REVIEWER'S CONCLUSIONS: The absolute and comparative efficacy and tolerability of anti-spasticity agents in multiple sclerosis is poorly documented and no recommendations can be made to guide prescribing. The rationale for treating features of the upper motor neurone syndrome must be better understood and sensitive, validated spasticity measures need to be developed.

Flexion vs. extension: a comparison of post-operative total knee arthroplasty mobilisation regimes.

We report a prospective trial comparing the effectiveness of a post-operative flexion regime versus a standard extension regime on the early outcome of total knee arthroplasty. A total of 160 knees were allocated to two separate post-operative mobilisation regimes: a static flexion regime or an active extension regime. Patients were implanted with either an IBII or 913 total knee replacement systems. All operations were performed by the same surgeon. Patients were assessed pre-operatively and at 6 weeks, and were well matched with respect to age, sex, diagnosis and pre-op movement. Patients subjected to the flexion regime had a better maximum flexion and range of movement at 6 weeks and were also discharged earlier. These results were statistically significant (P < 0.05). Histograms of results at 6 weeks show that the flexion group had a more predictable outcome with smaller standard deviations (S.D.) than the extension group. Differences were also observed in the percentage of 'sub-optimal' results. No difference was observed in post-operative wound problems. We believe a static flexion regime is as good as reported results with CPM, better than an extension regime and does not result in an increase in wound problems.

A straightforward method of assessing the accuracy of implantation of knee prostheses.

Accurate component placement in knee replacement surgery is important. The precision with which the implants are placed directly affects patient outcome as implant position and alignment influence stability, durability and patellar tracking. The ability to measure the accuracy of implantation of knee replacement components is valuable in assessing not only ones own technique but also in evaluating new instruments or implants and in teaching. The standard AP and lateral radiographs employed by most surgeons give inadequate information to assess alignment of each component accurately. We present a straightforward way of assessing femoral and tibial component alignment by using a series of three radiographs. This technique is reproducible and can be performed using standard equipment in any radiology department. This technique was applied to 160 total knee replacements performed using newly developed instrumentation. It was shown to be simple and the measurements were reproducible, with very little inter observer bias. We believe this technique has a role in audit, teaching, training and assessing new techniques and instruments.

Anti-spasticity agents for multiple sclerosis.

BACKGROUND: Spasticity is a common problem in MS patients causing pain, spasms, loss of function and difficulties in nursing care. A variety of oral and parenteral medications are available. OBJECTIVES: To assess the absolute and comparative efficacy and tolerability of anti-spasticity agents in multiple sclerosis (MS) patients. SEARCH STRATEGY: Randomised controlled trials (RCTs) of anti-spasticity agents were identified using MEDLINE, EMBASE, bibliographies of relevant articles, personal communication, manual searches of relevant journals and information from drug companies. SELECTION CRITERIA: Double-blind, randomised controlled trials (either placebo-controlled or comparative studies) of at least seven days duration. DATA COLLECTION AND ANALYSIS: Two independent reviewers extracted data and the findings of the trials were summarised. Missing data were collected by correspondence with principal investigators. A meta-analysis was not performed due to the inadequacy of outcome measures and methodological problems with the studies reviewed. MAIN RESULTS: Twenty-three placebo-controlled studies (using baclofen, dantrolene, tizanidine, botulinum toxin, vigabatrin, prazepam and threonine) and thirteen comparative studies met the selection criteria. Only thirteen of these studies used the Ashworth scale, of which only three of the six placebo-controlled trials and none of the seven comparative studies showed a statistically significant difference between test drugs. Spasms, other symptoms and overall impressions were only assessed using unvalidated scores and results of functional assessments were inconclusive. REVIEWER'S CONCLUSIONS: The absolute and comparative efficacy and tolerability of anti-spasticity agents in multiple sclerosis is poorly documented and no recommendations can be made to guide prescribing. The rationale for treating features of the upper motor neurone syndrome must be better understood and sensitive, validated spasticity measures need to be developed.

Trapezoid dislocation with a Galeazzi fracture.

A case of volar trapezoid dislocation and Galeazzi fracture in a 28-year-old man is presented. This case illustrates some of the problems associated with diagnosis and treatment of this rare injury.

The use of semipermeable dressings in fingertip injuries.

A randomised prospective trial was carried out to compare the use of semipermeable and petroleum gauze dressings in fingertip injuries. The results demonstrate advantages in the use of semipermeable dressings.

A simple adjustable functional brace for tibial fractures.

The use of an adjustable functional brace for fractures of the tibia has several practical and theoretical advantages. The high cost of commercially available braces has limited their use until now. We describe a simple, inexpensive orthosis which has given good results in a clinical study for 32 unselected fractures. The fractures' alignment was well maintained. The brace was comfortable to wear and there were few complications. It is hoped that the low cost of this simple custom-made brace will encourage more widespread use of this technique.

MacIntosh arthroplasty for the rheumatoid knee: a 10-year follow up.

The results of 75 MacIntosh arthroplasties performed for rheumatoid arthritis of the knee in 63 patients were reviewed at least 10 years after surgery. Forty-two knees in 35 patients were available for assessment. Eleven arthroplasties had been revised to total knee replacement without difficulty because of pain or poor function. The remaining 31 knees in 25 patients gave good or excellent results in 22 cases, fair in eight, and poor in one. Seven patients could not be traced, and 21 patients representing 26 knees had died. At least half these knees had given satisfactory results immediately before death judged by review of the case notes. The difficulty of comparing functional status with the preoperative state because of progressive multiarticular disease was highlighted. Although greater angular deformities preoperatively reduced the chance of success in the medium term, late failure of the arthroplasty after five years was very rare. Approximately two-thirds of all the arthroplasties performed gave satisfactory results at 10-year follow up or until the time of death.

Reflex inhibition of the quadriceps after meniscectomy: lack of association with pain.

We have examined the severity and duration of reflex inhibition of quadriceps activation after arthrotomy and meniscectomy, its relationship with pain, and the effect of local anaesthesia on this relationship. Fourteen men, on completion of medial meniscectomy by arthrotomy, received either 10 ml (B10 group) or 15 ml (B15 group) of 0.5% bupivacaine hydrochloride ('Marcaine Plain') into the knee, or no injection (control group). Reflex inhibition of quadriceps was measured as the percentage reduction, from the ipsilateral preoperative value, in the integrated surface electromyogram recorded during maximal voluntary isometric contractions with the knee in extension. Pain during each contraction was recorded on a linear analogue scale. Unoperated limbs showed no evidence of quadriceps inhibition. In the operated limbs, at 1-2 h post-operatively, controls had both severe inhibition (median = 62%) and severe pain on attempting a maximal quadriceps contraction. The B10 group had similar inhibition but less pain (P less than or equal to 0.005, Wilcoxon 2-sample, 1-tailed test). In the B15 group both inhibition (P less than or equal to 0.05) and pain (P less than or equal to 0.01) were less than in the controls. These effects of bupivacaine had been lost by 4-5 h post-operatively. At 3-4 days, inhibition was still severe (median = 75%) in all three groups of patients but pain was only mild or absent. At 10-15 days, median inhibition was still 35%, but there was little or no pain. We conclude that postmeniscectomy inhibition is not simply due to perceived pain but is due, at least in part, to stimuli from the knee.