Use of a trauma registry to drive improvement in the regional trauma network systems in Hawassa, Ethiopia

AIM

Our aim is to establish and analyse the first year of trauma registry data from Hawassa University Comprehensive Specialised Hospital (HUCSH)-an Ethiopian tertiary referral centre. We plan to identify possible trends in injury patterns, access to health care and referral pathways and establish if our observations are in keeping with data published from other sub-Saharan LMIC's.

METHODS

Prospective data collection using the WHO trauma registry dataset. All trauma patients presenting to HUCSH between November 2019 and November 2020 were included. Military patients were excluded.

DATASET

Age, sex, region of residence, mode of transport to hospital, referral centre, time from injury to arrival in HUCSH, arrival triage category, Kampala Trauma Score (KTS), mechanism of injury, injury type, closed/open fracture and 24 h outcomes. Data statistical analysis was performed to calculate frequencies of the above variables.

RESULTS

There were a total of 1919 cases. Fifty-three per cent were caused by road traffic collision and 49% were fracture/dislocations. Public transport was the most common mode to hospital-40%. Seventy-seven per cent of all trauma admissions were referred from other centres, 69% had a mild KTS. A total of 376 patients presented with an open fracture-76% had a low KTS and 67% remained in ED for > 24 h. Sixty-five per cent of ambulances were utilised for mild KTS patients, only 25% of ambulances transported moderate and severe injuries.

CONCLUSION

We have shown that a 'one size fits all approach' should not be adopted for LMIC's as trends vary between regions and countries. Improvements are needed in ambulance utilisation, the use of appropriate triaging tools to facilitate initial basic trauma care and appropriate, timely referrals and the management of open fractures.

Systematic review of complications associated with treatment by traditional bone setters for musculoskeletal injury

In order to synthesise the existing evidence of Traditional Bone Setters' (TBS) treatment and its associated complications in Low and Middle Income Countries (LMICs), we conducted a literature search following PRISMA guidelines. The keywords "traditional bone setter", "traditional bone healer", "traditional bone setting", "fracture", "complication", "low income country"," low to middle income country", "poor outcome" and "death" were searched in PubMed. Articles included in the review demonstrated complications associated with treatment by TBS for Musculoskeletal injury in LMICs. Out of 878 papers screened, twelve studies were finally included for review. Seven were prospective, and five retrospective studies. All were observational studies with all but one hospital based, the remaining being community based, and investigated the outcomes of treatment of fractures by traditional bonesetters published between 1999 and 2020 in LMICs. In total, this review covers 833 participants with 691 complications of TBS treatment. We identify a significant number of limb and life-threatening complications including mortality associated with the treatment by TBS. However, recent studies have shown that TBS are willing and keen to engage with local orthodox services and training courses. As shown in many countries, this can lead to a reduction in complications including mortality and can form a favourable environment where TBS and orthodox services can work side by side.

Use of directed acyclic graphs (DAGs) to identify confounders in applied health research: review and recommendations

Background

Directed acyclic graphs (DAGs) are an increasingly popular approach for identifying confounding variables that require conditioning when estimating causal effects. This review examined the use of DAGs in applied health research to inform recommendations for improving their transparency and utility in future research.

Methods

Original health research articles published during 1999–2017 mentioning ‘directed acyclic graphs’ (or similar) or citing DAGitty were identified from Scopus, Web of Science, Medline and Embase. Data were extracted on the reporting of: estimands, DAGs and adjustment sets, alongside the characteristics of each article’s largest DAG.

Results

A total of 234 articles were identified that reported using DAGs. A fifth (n = 48, 21%) reported their target estimand(s) and half (n = 115, 48%) reported the adjustment set(s) implied by their DAG(s). Two-thirds of the articles (n = 144, 62%) made at least one DAG available. DAGs varied in size but averaged 12 nodes [interquartile range (IQR): 9–16, range: 3–28] and 29 arcs (IQR: 19–42, range: 3–99). The median saturation (i.e. percentage of total possible arcs) was 46% (IQR: 31–67, range: 12–100). 37% (n = 53) of the DAGs included unobserved variables, 17% (n = 25) included ‘super-nodes’ (i.e. nodes containing more than one variable) and 34% (n = 49) were visually arranged so that the constituent arcs flowed in the same direction (e.g. top-to-bottom).

Conclusion

There is substantial variation in the use and reporting of DAGs in applied health research. Although this partly reflects their flexibility, it also highlights some potential areas for improvement. This review hence offers several recommendations to improve the reporting and use of DAGs in future research.

178 Suspected Cauda Equina Syndrome in a District General Hospital

Introduction

Cauda Equina Syndrome (CES) is rare but when the diagnosis is delayed patient morbidity is significant. Recently, NICE Clinical Knowledge Summaries have updated their red flags on CES to be more explicit enabling earlier referral and diagnosis. A joint project between Orthopaedics and Radiology departments aimed to assess the current pathway of Cauda Equina Investigation at a District General Hospital.

Method

Data was collected from the local Radiology database for requests between July 2017 and August 2018. This included both direct requests to assess for CES and implied. Raw data revealed a potential of 600 patients, of which we have analysed 332 patients met the eligibility criteria.

Results

Only 58 patients had a documented complete bladder function assessment, of those 33% had incomplete or partial bladder emptying. Time to MRI scan ranged from 50mins – 23 hours & 52 mins. 47% had negative scans with CES or Cord compromise on MRI scan was demonstrated on 9%. 23 patients were transferred urgently to the receiving tertiary centre.

Conclusions

We found that nearly 90% of patients were being incompletely assessed and time to scan ranged significantly. We are producing a trust wide suspected CES pathway to improve patient assessment.

Coronavirus infection in hip fractures (CHIP) study

AIMS

Despite the COVID-19 pandemic, incidence of hip fracture has not changed. Evidence has shown increased mortality rates associated with COVID-19 infection. However, little is known about the outcomes of COVID-19 negative patients in a pandemic environment. In addition, the impact of vitamin D levels on mortality in COVID-19 hip fracture patients has yet to be determined.

METHODS

This multicentre observational study included 1,633 patients who sustained a hip fracture across nine hospital trusts in North West England. Data were collected for three months from March 2020 and for the same period in 2019. Patients were matched by Nottingham Hip Fracture Score (NHFS), hospital, and fracture type. We looked at the mortality outcomes of COVID-19 positive and COVID-19 negative patients sustaining a hip fracture. We also looked to see if vitamin D levels had an impact on mortality.

RESULTS

The demographics of the 2019 and 2020 groups were similar, with a slight increase in proportion of male patients in the 2020 group. The 30-day mortality was 35.6% in COVID-19 positive patients and 7.8% in the COVID-19 negative patients. There was a potential association of decreasing vitamin D levels and increasing mortality rates for COVID-19 positive patients although our findings did not reach statistical significance.

CONCLUSION

In 2020 there was a significant increase in 30-day mortality rates of patients who were COVID-19 positive but not of patients who were COVID-19 negative. Low levels of vitamin D may be associated with high mortality rates in COVID-19 positive patients. Cite this article: Bone Joint J 2021;103-B(4):782-787.

DAG-informed regression modelling, agent-based modelling and microsimulation modelling: a critical comparison of methods for causal inference

The current paradigm for causal inference in epidemiology relies primarily on the evaluation of counterfactual contrasts via statistical regression models informed by graphical causal models (often in the form of directed acyclic graphs, or DAGs) and their underlying mathematical theory. However, there have been growing calls for supplementary methods, and one such method that has been proposed is agent-based modelling due to its potential for simulating counterfactuals. However, within the epidemiological literature, there currently exists a general lack of clarity regarding what exactly agent-based modelling is (and is not) and, importantly, how it differs from microsimulation modelling-perhaps its closest methodological comparator. We clarify this distinction by briefly reviewing the history of each method, which provides a context for their similarities and differences, and casts light on the types of research questions that they have evolved (and thus are well suited) to answering; we do the same for DAG-informed regression methods. The distinct historical evolutions of DAG-informed regression modelling, microsimulation modelling and agent-based modelling have given rise to distinct features of the methods themselves, and provide a foundation for critical comparison. Not only are the three methods well suited to addressing different types of causal questions, but, in doing so, they place differing levels of emphasis on fixed and random effects, and also tend to operate on different timescales and in different timeframes.

Duct Stenting Versus Modified Blalock-Taussig Shunt in Neonates With Duct-Dependent Pulmonary Blood Flow

Background:

Infants born with cardiac abnormalities causing dependence on the arterial duct for pulmonary blood flow are often palliated with a shunt usually between the subclavian artery and either pulmonary artery. A so-called modified Blalock-Taussig shunt allows progress through early life to an age and weight at which repair or further more stable palliation can be safely achieved. Modified Blalock-Taussig shunts continue to present concern for postprocedural instability and early mortality such that other alternatives continue to be explored. Duct stenting (DS) is emerging as one such alternative with potential for greater early stability and improved survival.

Methods:

The purpose of this study was to compare postprocedural outcomes and survival to next-stage palliative or reparative surgery between patients undergoing a modified Blalock-Taussig shunt or a DS in infants with duct-dependent pulmonary blood flow. All patients undergoing cardiac surgery and congenital interventions in the United Kingdom are prospectively recruited to an externally validated national outcome audit. From this audit, participating UK centers identified infants <30 days of age undergoing either a Blalock-Taussig shunt or a DS for cardiac conditions with duct-dependent pulmonary blood flow between January 2012 and December 31, 2015. One hundred seventy-one patients underwent a modified Blalock-Taussig shunt, and in 83 patients, DS was attempted. Primary and secondary outcomes of survival and need for extracorporeal support were analyzed with multivariable logistic regression. Longer-term mortality before repair and reintervention were analyzed with Cox proportional hazards regression. All multivariable analyses accommodated a propensity score to balance patient characteristics between the groups.

Results:

There was an early (to discharge) survival advantage for infants before next-stage surgery in the DS group (odds ratio, 4.24; 95% confidence interval, 1.37–13.14; P =0.012). There was also a difference in the need for postprocedural extracorporeal support in favor of the DS group (odds ratio, 0.22; 95% confidence interval, 0.05–1.05; P =0.058). Longer-term survival outcomes showed a reduced risk of death before repair in the DS group (hazard ratio, 0.25; 95% confidence interval, 0.07–0.85; P =0.026) but a slightly increased risk of reintervention (hazard ratio, 1.50; 95% confidence interval, 0.85–2.64; P =0.165).

Conclusions:

DS is emerging as a preferred alternative to a surgical shunt for neonatal palliation with evidence for greater postprocedural stability and improved patient survival to destination surgical treatment.

Establishing a children's orthopaedic hospital for Malawi: A review after 10 years

BACKGROUND

BEIT CURE International Hospital (BCIH) opened in 2002 providing orthopaedic surgical services to children in Malawi. This study reviews the hospital's progress 10 years after establishment of operational services. In addition we assess the impact of the hospital's Malawi national clubfoot programme (MNCP) and influence on orthopaedic training.

METHODS

All operative paediatric procedures performed by BCIH services in the 10th operative year were included. Data on clubfoot clinic locations and number of patients treated were obtained from the MNCP. BCIH records were reviewed to identify the number of healthcare professionals who have received training at the BCIH.

RESULTS

609 new patients were operated on in the 10th year of hospital service. Patients were treated from all regions; however 60% came from Southern regions compared with the 48% in the 5th year. Clubfoot, burn contracture and angular lower limb deformities were the three most common pathologies treated surgically. In total BCIH managed 9,842 patients surgically over a 10-year period. BCIH helped to establish and co-ordinate the MNCP since 2007. At present the program has a total of 29 clinics, which have treated 5748 patients. Furthermore, BCIH has overseen the full or partial training of 5 orthopaedic surgeons and 82 orthopaedic clinical officers in Malawi.

CONCLUSION

The BCIH has improved the care of paediatric patients in a country that prior to its establishment had no dedicated paediatric orthopaedic service, treating almost 10,000 patients surgically and 6,000 patients in the MNCP. This service has remained consistent over a 10-year period despite times of global austerity. Whilst the type of training placement offered at BCIH has changed in the last 10 years, the priority placed on training has remained paramount. The strategic impact of long-term training commitments are now being realised, in particular by the addition of Orthopaedic surgeons serving the nation.

Avascular necrosis of the femoral head in HIV positive patients-an assessment of risk factors and early response to surgical treatment

26 consecutive patients (37 hips) with avascular necrosis (AVN) of the femoral head treated surgically at our institution from 1999 to 2008 were reviewed. The aims of the study were to evaluate the risk factors associated with AVN in HIV positive and HIV negative individuals, and assess early response to total hip replacement (THR) surgery in HIV positive and negative patients. There were 15 male and 11 female patients in total. The mean age for all patients was 47.1± 8.0 years (range, 33 to 66 years). 12 patients were HIV positive, 11 patients were HIV negative and 3 patients had unknown HIV status. Excessive alcohol intake was the most common risk factor for developing AVN .15 patients (58%) had more than one risk factor for AVN and only 2/12 (17%) HIV positive patients had no other risk factor apart from HIV infection. There were no early postoperative complications in 34 arthroplasties in both HIV positive and negative patients. The aetiology of AVN seems often to be multifactorial, even in the presence of HIV infection. Early response to arthroplasty surgery in AVN of the femoral head is equally good irrespective of the HIV serostatus of the patients.

The incidence and consequences of early wound infection after internal fixation for trauma in HIV-positive patients

We report a prospective single-blind controlled study of the incidence of early wound infection after internal fixation for trauma in 609 patients, of whom 132 were HIV-positive. Wounds were assessed for healing using the ASEPSIS score. There was no significant difference in the rate of infection between HIV-positive and HIV-negative patients undergoing clean surgery (4.2% vs 6%, respectively; p = 0.65). HIV-positive patients did not receive additional antibiotic prophylaxis or antiretroviral therapy as part of their management. The difference in the rate of infection between HIV-positive and HIV-negative patients with an open fracture or other contamination was not significant (33% vs 15%, respectively; p = 0.064). There was no relationship between CD4 count and infection rate. HIV status did not significantly influence the number of secondary surgical procedures (p = 0.183) or the likelihood of developing chronic osteomyelitis (p = 0.131). Although previous contamination from the time of injury was a risk factor for infection in mal- and nonunions, it was not significantly increased in HIV-positive patients (p = 0.144). We conclude that clean implant surgery in HIV-positive patients is safe, with no need for additional prophylaxis.

Hip and knee replacement in the HIV positive patient

Arthroplasty is used to relieve pain associated with degenerative or inflammatory joint disease, some post-traumatic joint problems, and avascular necrosis. Avascular necrosis, inflammatory and post-traumatic problems are seen on a regular basis in areas of high HIV seroprevalence. Degenerative arthritis is rare in younger HIV patients, however. Historically the only group of HIV patients in which arthroplasty has been common is that which received contaminated factor VIII transfusions in the 1980's. Haemophiliacs get a haemophilic arthropathy from repeated bleeds into joints and so is an additional complication. Much of the previous literature on this topic has focused on haemophiliac patients. This review examines the success of arthroplasty in HIV positive patients, with an emphasis on non-haemophiliac patients. We conclude that arthroplasty can be a safe procedure for HIV positive individuals if the surgery is carried out in good conditions, and early results are encouraging.

Chronic haematogenous osteomyelitis in children: an unsolved problem

From a global point of view, chronic haematogenous osteomyelitis in children remains a major cause of musculoskeletal morbidity. We have reviewed the literature with the aim of estimating the scale of the problem and summarising the existing research, including that from our institution. We have highlighted areas where well-conducted research might improve our understanding of this condition and its treatment.

Multilevel latent class casemix modelling: a novel approach to accommodate patient casemix

BACKGROUND

Using routinely collected patient data we explore the utility of multilevel latent class (MLLC) models to adjust for patient casemix and rank Trust performance. We contrast this with ranks derived from Trust standardised mortality ratios (SMRs).

METHODS

Patients with colorectal cancer diagnosed between 1998 and 2004 and resident in Northern and Yorkshire regions were identified from the cancer registry database (n = 24,640). Patient age, sex, stage-at-diagnosis (Dukes), and Trust of diagnosis/treatment were extracted. Socioeconomic background was derived using the Townsend Index. Outcome was survival at 3 years after diagnosis. MLLC-modelled and SMR-generated Trust ranks were compared.

RESULTS

Patients were assigned to two classes of similar size: one with reasonable prognosis (63.0% died within 3 years), and one with better prognosis (39.3% died within 3 years). In patient class one, all patients diagnosed at stage B or C died within 3 years; in patient class two, all patients diagnosed at stage A, B or C survived. Trusts were assigned two classes with 51.3% and 53.2% of patients respectively dying within 3 years. Differences in the ranked Trust performance between the MLLC model and SMRs were all within estimated 95% CIs.

CONCLUSIONS

A novel approach to casemix adjustment is illustrated, ranking Trust performance whilst facilitating the evaluation of factors associated with the patient journey (e.g. treatments) and factors associated with the processes of healthcare delivery (e.g. delays). Further research can demonstrate the value of modelling patient pathways and evaluating healthcare processes across provider institutions.

Open tibia fractures in HIV positive patients

Open tibia fractures are common injuries, particularly in developing countries.Pedestrian or bicycle to motor car contact is the most common mechanism. These injuries result in high morbidity and often long-term disability. HIV infection complicates open fractures by raising the incidence of infectionin the open wound (5 of 7 patients in our series). This risk may be compounded if internal fixation techniques are used (5 of 12 HIV patients with internal fixation of any open fracture). There is also a suggestion that HIV may delay bone union (4 of 7 patients united at 6 months). External fixation offers an alternative method of fracture stabilisation. It avoids the risks associated with putting metal-ware in the wound, but creates a new issue of pin track sepsis. We found that pin track infection was more common in patients with HIV, but the rate at which pins required removal was 7%. We consider external fixation to be a lower-risk strategy than internal fixation in such patients but open fracture wound sepsis remains a problem. We have not yet demonstrated a difference in severity or frequency of complications in patients of low CD4 count, but logically one expects septic complications to increase as CD4 count falls. Antiretroviral medication decreases viral load and elevates the CD4 count. Research is underway regarding potential effectiveness of such drugs in reducing wound and fracture healing complications. Above all, meticulous and timely all-round care is required to achieve satisfactory results in immune-compromised patients. This includes, debridement, bony stability, and soft-tissue reconstruction.

The effects of introducing artemether-lumefantrine malaria treatment and insecticide-impregnated bed nets to an elective surgical hospital

Malaria and anaemia in patients admitted for elective orthopaedic operations commonly cause delays to surgery. Our hospital has introduced artemether-lumefantrine as the standard treatment for malaria in accordance with the national policy, replacing sulphadoxine-pyrimethamine. Insecticide-impregnated bed nets were also introduced throughout our wards. A retrospective audit of all new elective surgical admissions over a 12-month period was performed in order to assess the effect of these changes. The study was designed to follow an identical audit performed before their introduction. Of the 435 patients admitted, 75 (17.2%) had malaria parasites present on blood film. In these patients, surgery was significantly delayed, by a mean of 9.9 days more than the group without malaria ( P < 0.001). Before the changes to malaria treatment, the mean delay was 2.2 days ( P < 0.05). Six patients (1.7%) developed malaria during admission, significantly fewer than the 16 (4.3%) before the introduction of bed nets ( P = 0.036). The average haemoglobin level on admission in patients with malaria parasites was 11.8 g/dL (95% confidence interval [CI] 11.4–12.2) and in those without 13.1 g/dL (95% CI: 12.9–13.3). Seventeen patients (3.9%) were admitted with a haemoglobin concentration of <10 g/dL and two (0.5%) of <8 g/dL. There were no significant delays to surgery in these patients compared to those without anaemia. The adoption of artemether-lumefantrine by our hospital significantly increased delays to surgery. The introduction of insecticide-impregnated bed nets significantly reduced the number of patients developing malaria during their hospital stay.

Chronic haematogenous osteomyelitis in children: a retrospective review of 167 patients in Malawi

We present a retrospective review of 167 patients aged 18 years and under who were treated for chronic haematogenous osteomyelitis at our elective orthopaedic hospital in Malawi over a period of four years. The median age at presentation was eight years (1 to 18). There were 239 hospital admissions for treatment during the period of the study. In 117 patients one admission was necessary, in 35 two, and in 15 more than two. A surgical strategy of infection control followed by reconstruction and stabilisation was employed, based on the Beit CURE radiological classification of chronic haematogenous osteomyelitis as a guide to treatment. At a minimum follow-up of one year after the end of the study none of the patients had returned to our hospital with recurrent infection. A total of 350 operations were performed on the 167 patients. This represented 6.7% of all children's operations performed in our hospital during this period. One operation only was required in 110 patients and none required more than three. Below-knee amputation was performed in two patients with chronic calcaneal osteomyelitis as the best surgical option for function. The most common organism cultured from operative specimens was Staphylococcus aureus, and the tibia was the bone most commonly affected. Polyostotic osteomyelitis occurred in four patients. We believe this is the largest reported series of patients treated for chronic haematogenous osteomyelitis.

Amputation surgery in children: an analysis of frequency and cause of early wound problems

Amputation surgery in children is a relatively uncommon procedure. The objective of our study was to determine the incidence of complications in this type of surgery as well as any related factors. The results of our retrospective study of children aged between one and 18 years, over a five-year period were collected and analysed. The most frequent indications for amputation were congenital limb deformities (60%). Trauma, tumours, infection and other rare conditions were less common.

Results also revealed that in our hospital the wound infection rate was 38 %, the wound breakdown rate was 11 % and the general wound sepsis rate was around 1%. More complications were observed following through-knee amputation. We had noticed fewer complications (25%) when the surgery was performed by a consultant than when it was performed by a junior trainee (66%).

Joint replacement in Malawi: establishment of a National Joint Registry

In Africa the amount of joint replacement surgery is increasing, but the indications for operation and the age of the patients are considerably different from those in the developed world. New centres with variable standards of care and training of the surgeons are performing these procedures and it is important that a proper audit of this work is undertaken. In Malawi, we have pioneered a Registry which includes all joint replacements that have been carried out in the country. The data gathered include the age, gender, indication for operation, the prosthesis used, the surgical approach, the use of bone graft, the type of cement, pressurising systems and the thromboprophylaxis used. All patients have their clinical scores recorded pre-operatively and then after three and six months and at one year. Before operation all patients are counselled and on consent their HIV status is established allowing analysis of the effect of HIV on successful joint replacement. To date, 73 total hip replacements (THRs) have been carried out in 58 patients by four surgeons in four different hospitals. The most common indications for THR were avascular necrosis (35 hips) and osteoarthritis (22 hips). The information concerning 20 total knee replacements has also been added to the Registry.

Rietveld refinement of Sr(5)(AsO(4))(3)Cl from high-resolution synchrotron data

The apatite-type compound, penta­strontium tris­[arsenate(V)] chloride, Sr₅(AsO₄)₃Cl, has been synthesized by ion exchange at high temperature from a synthetic sample of mimetite [Pb₅(AsO₄)₃Cl] with SrCO₃ as a by-product. The results of the Rietveld refinement, based on high resolution synchrotron X-ray powder diffraction data, show that the title compound crystallizes in the same structure as other halogenoapatites with general formula A₅(YO₄)₃X (A = divalent cation, Y = penta­valent cation, and X = F, Cl or Br) in the space group P6₃/m. The structure consists of isolated tetra­hedral AsO₄³⁻ anions (the As atom and two O atoms have m symmetry), separated by two crystallographically independent Sr²⁺ cations that are located on mirror planes and threefold rotation axes, respectively. One Sr atom is coordinated by nine O atoms and the other by six. The chloride anions (site symmetry ) are at the 2a sites and are located in the channels of the structure.

Rietveld refinement of Ba(5)(AsO(4))(3)Cl from high-resolution synchrotron data

The apatite-type compound Ba₅(AsO₄)₃Cl, penta­barium tris­[arsenate(V)] chloride, has been synthesized by ion exchange at high temperature from a synthetic sample of mimetite (Pb₅(AsO₄)₃Cl) with BaCO₃ as a by-product. The results of the Rietveld refinement, based on high resolution synchrotron X-ray powder diffraction data, show that the title compound crystallizes in the same structure as other halogenoapatites with general formula A₅(YO₄)₃X (A = divalent cation, Y = penta­valent cation, X = Cl, Br) in space group P6₃/m. The structure consists of isolated tetra­hedral AsO₄³⁻ anions (m symmetry), separated by two crystallographically independent Ba²⁺ cations that are located on mirror planes and threefold rotation axes, respectively. The Cl⁻ anions are at the 2b sites ( symmetry) and are located in the channels of the structure.

Effects of honey and sugar dressings on wound healing

OBJECTIVE

To investigate whether there is a difference between the efficacy of honey and sugar as wound dressings.

METHOD

Patients with open or infected wounds were randomised to receive either honey or sugar dressings. Bacterial colonisation, wound size, wound ASEPSIS score and pain were assessed at the start of treatment and at weekly intervals until full healing occurred.

RESULTS

Forty patients were enrolled; 18 received sugar dressings and 22 honey dressings. In the honey group, 55% of patients had positive wound cultures at the start of treatment and 23% at one week, compared with 52% and 39% respectively in the sugar group.The median rate of healing in the first two weeks of treatment was 3.8cm2/week for the honey group and 2.2cm2/week for the sugar group. After three weeks of treatment 86% of patients treated with honey had no pain during dressing changes, compared with 72% treated with sugar.

CONCLUSION

Honey appears to be more effective than sugar in reducing bacterial contamination and promoting wound healing, and slightly less painful than sugar during dressing changes and motion.

Pin-track infection in HIV-positive and HIV-negative patients with open fractures treated by external fixation

Patients infected with HIV presenting with an open fracture of a long bone are difficult to manage. There is an unacceptably high rate of post-operative infection after internal fixation. There are no published data on the use of external fixation in such patients. We compared the rates of pin-track infection in HIV-positive and HIV-negative patients presenting with an open fracture. There were 47 patients with 50 external fixators, 13 of whom were HIV-positive (15 fixators).

There were significantly more pin-track infections requiring pharmaceutical or surgical intervention (Checketts grade 2 or greater) in the HIV-positive group (t-test, p = 0.001). The overall rate of severe pin-track infection in the HIV-positive patients requiring removal of the external-fixator pins was 7%. This contrasts with other published data which have shown higher rates of wound infection if open fractures are treated by internal fixation.

We recommend the use of external fixation for the treatment of open fractures in HIV-positive patients.

Open fractures of the tibia in HIV positive patients: a prospective controlled single-blind study

Twenty-seven patients with severe open fractures were studied prospectively analysing infection and union as outcome measures. A standard treatment regime was applied. Seven patients were HIV positive, and 20 patients HIV negative. Wound infection and delayed union were more common in HIV positive patients. The difference in rate of infection was statistically significant (P = 0.020), while that in union did not quite reach significance (P = 0.059). The authors have developed an algorithm for treatment of these injuries in areas of high seroprevalence of HIV infection.

One-year follow-up of orthopaedic implants in HIV-positive patients

We followed prospectively 38 orthopaedic implants in 36 HIV-positive patients. X-rays and clinical examination were used to assess union, and observation was made for early and late wound sepsis for 12 months from the time of surgery. Two patients died of causes unrelated to the implantation, two patients had implants removed for reasons other than infection and eight cases were lost to follow-up. Of the 26 cases that were reviewed at 1 year, no late sepsis was identified. All of the fractures, non-unions, osteotomies and arthrodeses united. The literature indicates that late sepsis following arthroplasty occurs more frequently in haemophiliacs who are HIV positive than their HIV-negative counterparts. It is still not certain whether or not such a risk also applies to HIV-positive patients who are not haemophiliacs and have undergone internal fixation of fractures or non-unions. This study increases the confidence that fixation in immune-compromised patients with intact skin is safe, at least for the time period that the implant is required. Further studies are required to know whether or not fixation implants should be removed.

Wound healing after implant surgery in HIV-positive patients

We performed a prospective, blind, controlled study on wound infection after implant surgery involving 41 procedures in patients infected with the human immunodeficiency virus (HIV) and 141 in HIV-negative patients. The patients were staged clinically and the CD4 cell count determined. Wound infection was assessed using the asepsis wound score. A risk category was allocated to account for presurgical contamination. In HIV-positive patients, with no preoperative contamination, the incidence of wound infection (3.5%) was comparable with that of the HIV-negative group (5%; p = 0.396). The CD4 cell count did not affect the incidence of infection (r = 0.16). When there was preoperative contamination, the incidence of infection in HIV-positive patients increased markedly (42%) compared with that in HIV-negative patients (11%; p = 0.084). Our results show that when no contamination has occurred implant surgery may be undertaken safely in HIV-positive patients.

Delay in skeletal maturity in Malawian children

The atlas of Greulich and Pyle for skeletal maturity and epiphyseal closure is widely used in many countries to assess skeletal age and to plan orthopaedic surgery. The data used to compile the atlas were collected from institutionalised American children in the 1950s. In order to determine whether the atlas was relevant to subSaharan Africa, we compared skeletal age, according to the atlas, with chronological age in 139 skeletally immature Malawian children and young adults with an age range from 1 year 11 months to 28 years 5 months. The height and weight of each patient were also measured in order to calculate the body mass index. The skeletal age of 119 patients (85.6%) was lower than the chronological age. The mean difference was 20.0+/-24.1 months (t-test, p = 0.0049), and the greatest difference 100 months. The atlas is thus inaccurate for this group of children. The body mass index in 131 patients was below the normal range of 20 to 25 kg/m2. The reasons for the low skeletal age in this group of children are discussed. Poor nutrition and chronic diseases such as malaria and diarrhoea which are endemic in Malawi are likely to be contributing factors. We did not find any correlation between the reduction in body mass index in our patients and the degree of retardation of skeletal age.

Audit of deep wound infection following hip fracture surgery

An audit of 171 consecutive hip fractures treated surgically showed a deep wound infection rate of 3.6%. Several shortcomings in the implementation of the infection policy were identified and recommendations to eliminate them introduced. Review of the subsequent 186 patients gave a deep infection rate of 1.1%. Attention to detail and good practice are essential to maintain low wound infection rates.

Osteogenesis imperfecta in Zimbabwe: a comparison between treatment with intramedullary rods of fixed-length and self-expanding rods

The results of surgical treatment of 15 children with osteogenesis imperfecta in Bulawayo, Zimbabwe are reviewed. A total of 23 self-expanding and 27 fixed-length rods were used. Outcome was measured in terms of mobility status, growth, incidence of refracture, need for reoperation, and complications. Eight of the children improved their mobility status over the course of treatment. Self-expanding rods appeared to confer more benefit to growth than fixed-length rods. Refracture was more common in bones splinted with fixed-length rods and more often necessitated revision surgery in these bones. The complication rate was high in all cases, but the complications associated with outgrown fixed-length rods were a particular problem. The 15 children benefited from surgical treatment. The self-expanding rods performed better than fixed-length rods in reducing the number of surgical interventions. They also appear to facilitate growth. The self-expanding rods may be used to good effect in appropriate centres in the developing world.

Increased tau messenger RNA in Alzheimer's disease hippocampus

The microtubule-associated protein tau is present in the pathologic hallmarks of Alzheimer's disease and its production and deposition have been implicated in the pathogenesis of the disease. We detected tau mRNA using in situ hybridization histochemistry in the hippocampus, visual cortex, and cerebellum, and compared its level in Alzheimer's disease with controls. The amount of tau mRNA also was determined as a ratio of total polyadenylated mRNA in each area. A significant and gene-specific increase in tau mRNA hybridization was found in hippocampal fields CA4 and CA3, with a similar trend in the dentate gyrus. In contrast, no change was found in the visual cortex or cerebellum in Alzheimer's disease. Increased hippocampal expression of tau mRNA also was present in cases of non-Alzheimer's dementia. Enhanced tau mRNA may be a marker of attempted plasticity involving the cytoskeleton in neuronal populations affected by various neurodegenerative disorders.

Supercomputer Analysis of Sedimentary Basins

Geological processes of fluid transport and chemical reaction in sedimentary basins have formed many of the earth's energy and mineral resources. These processes can be analyzed on natural time and distance scales with the use of supercomputers. Numerical experiments are presented that give insights to the factors controlling subsurface pressures, temperatures, and reactions; the origin of ores; and the distribution and quality of hydrocarbon reservoirs. The results show that numerical analysis combined with stratigraphic, sea level, and plate tectonic histories provides a powerful tool for studying the evolution of sedimentary basins over geologic time.

Non-Hodgkin's lymphoma: a survey from a district general hospital

We report a retrospective survey of 167 patients with non-Hodgkin's lymphoma (NHL) seen at a district general hospital between 1 August 1971 and 1 August 1983. Details of their clinical presentation, histology, therapy, response rates and survival are presented. The patient population reported is generally older than that seen at specialist centres and has a greater proportion of tumours with low-grade histology. Whereas specialist centres see a pre-selected population of patients, our data may be from a more representative group and this gives a truer incidence of this disease in the general population. The remission rates and overall survival of our patients are comparable to those achieved at specialist centres. We conclude that it is both feasible and desirable for patients with NHL to be assessed and treated in a district general hospital with a radiotherapy department.

The so-called intravascular bronchioloalveolar tumour of lung (low grade sclerosing angiosarcoma): presentation with extrapulmonary deposits

Two further cases of the so-called intravascular bronchioloalveolar tumour of lung are reported. Electron microscopic demonstration of Weibel-Palade bodies and immunocytochemical demonstration of factor VIII in the cytoplasm of the tumour cells indicate the vascular nature of these lesions. One patient presented with an enlarged liver and the tumour was found to be involving the liver and parietal pleura as well as the lung. The characteristic micropolypoid structure was not seen in the pleural or hepatic deposits and it is evident that this feature is a consequence of the alveolar architecture of the lung and is not an inherent property of the tumour.

Inflammatory bowel disease in ankylosing spondylitis

Routine detailed gastroenterological investigations were performed in a series of 47 ankylosing spondylitics. Evidence of chronic inflammatory bowel disease was found in eight patients, a prevalence of 17%. Unsuspected bowel disease was found in the absence of symptoms in three of these patients.

Out-of-focus images; some properties, uses, and a geometrical explanation

Out-of-focus images tend to move and split when obstructions are passed through or near the nodal planes of the image forming lens, while in-focus images do not show such effects. Geometrical optics is used to produce a qualitative explanation of these effects with the object of utilizing them for automatic focusing and rangefinding devices. Several problems in such devices are briefly discussed and a proposed automatic rangefinder is described.

Carcinoma, villous atrophy, and steatorrhoea

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