Fatigue symptoms in Sri Lanka Navy personnel deployed in combat areas.

OBJECTIVES: The objective was to study the prevalence of fatigue symptoms among Special Forces and regular forces military personnel deployed in combat areas and to explore factors associated with fatigue symptoms. METHODS: This is a cross sectional study of representative samples of Sri Lanka Navy Special Forces and regular forces deployed in combat areas continuously for at least one year. Fatigue was measured using a 12 item fatigue scale. Symptoms of common mental disorder were identified using the General Health questionnaire 12 (GHQ-12). Multiple physical symptoms were elicited using a checklist of symptoms. PTSD was diagnosed using the 17-item National Centre for PTSD checklist civilian version (PCL-C). RESULTS: Sample consisted of 259 Special Forces and 412 regular navy personnel. Prevalence of fatigue over the last month was 13.41% (95% CI 10.83-16.00). Prevalence was significantly less in the Special Forces (5.4%) than in the regular forces (18.4%) [OR 0.38 (95% CI 0.17-0.82)]. Only two types of combat exposure "thought I might be killed" and "coming under mortar, missile and artillery fire" were significantly associated with fatigue symptoms. Fatigue was strongly associated with symptoms of common mental illness [adjusted OR 12.82 (95% CI 7.10-23.12)], PTSD [adjusted OR 9.08 (95% CI 2.84-29.0)] and multiple somatic symptoms [adjusted OR 9.85 (95% CI 5.42-17.9)]. Fatigue was significantly associated with functional impairment. CONCLUSIONS: Prevalence of fatigue was significantly lower in the Special Forces despite high combat exposure. Fatigue was associated only with indicators of intense combat exposure. Fatigue caused significant functional impairment even after adjusting for psychological morbidity.

Hip resurfacing arthroplasty: A new method to assess and quantify learning phase.

Hip resurfacing had initially gained acceptance and popularity as it helps preserve femoral bone stock. In this study we tried to answer the following questions; 1. Whether there is a learning curve for hip resurfacing? 2. Is it present in surgeons from non-developer centres? 3. Is it present in surgeons from developer centres as well? The Oswestry outcome centre was setup to serve an independent international registry for collecting, analysing and reporting outcomes following hip resurfacing. Over a 10 year period, 4535 patients (5000 hips) were recruited from different countries and within the UK from different centres in this study by 139 surgeons from 37 different countries. Our study has shown that function can be used to assess the level of surgical competence. The results from this multilevel analysis have helped to answer the questions posed in the introduction. Hip resurfacing is a surgical procedure with a learning phase and this learning effect is more pronounced in non-developer surgeons as compared to developer surgeons. Hip scores can be used to assess proficiency and competence of surgeons undertaking hip resurfacing arthroplasty.

Peri-articular diseases of the hip: emerging frontiers in arthroscopic and endoscopic treatments.

The precise diagnosis of both intra and extra-capsular disease of the hip is now possible because of commonly available advanced diagnostic imaging techniques. An increasing number of reports in the orthopedic literature describe new endoscopic and arthroscopic techniques to address peri-articular pathology of the hip. The purpose of this paper is to review current techniques in the management of extra-articular hip conditions.

Medium term results of the collum femoris preserving hydroxyapatite coated total hip replacement.

We describe the survival of 75 collum femoris preserving (CFP) hydroxyapatite (HA) coated uncemented total hip replacement stems with a mean follow-up of 43 months (range 12-60). Patients were assessed using the Harris Hip Score. Radiographs were evaluated using Gruen zones and DeLee and Charnley zones. The criteria for failure were revision or impending revision. The mean Harris Hip Score was 50 preoperatively improving to 94 at final review, with 3 patients lost to follow-up. One cup was revised for aseptic loosening, whilst none of the stems required revision. Survivorship was 97% and 100% at 3 years for the cup and stem respectively. Our findings suggest that the medium term results of the CFP stem are excellent.

Does ligament balancing technique affect kinematics in rotating platform, PCL retaining knee arthroplasties? A prospective randomized study.

The goal of this prospective, randomized, blinded trial was to determine if ligament balancing techniques for rotating platform TKA affect postoperative knee kinematics. Sixteen patients with unilateral rotating platform TKA consented to participate in this institutional review board approved study. Eight patients were randomly selected to receive ligament balancing with an instrumented joint spreader device and eight patients received ligament balancing using fixed thickness spacer blocks. A single plane shape matching technique was used for kinematic analysis of static deep knee flexion and dynamic stair activities. There were no differences in knee kinematics between groups during static deep flexion activities. The spreader group demonstrated kinematics more similar to the normal knee during the ascending phase of the dynamic stair activity. Knee kinematics in static knee flexion were unaffected by ligament balancing technique, while knees balanced with the spreader demonstrated a medial pivot motion pattern during stair ascent. This medial pivot motion pattern may improve long-term results by more closely replicating normal knee kinematics.

Myositis ossificans traumatica of the thenar region.

Myositis ossificans of the hand is extremely rare. We report an unusual case of myositis ossificans of the thenar muscles and discuss the diagnostic pitfalls whereby this condition can be mistaken for malignancy or infection.

Physical examination of the carpal bones by orthopaedic and accident and emergency surgeons.

Our aim was to test knowledge of carpal bone surface anatomy among orthopaedic and accident and emergency surgeons. A survey of 58 surgeons was conducted. Each was asked to palpate seven points on five commonly injured carpal bones. Eight surgeons declined to participate. Five of the remaining 50 correctly palpated all surface markings. Six failed to accurately palpate even a single point. The scaphoid waist and trapezial ridge were accurately palpated by 47 surgeons. The median score for all participants was 3 correctly identified points. The majority of orthopaedic and accident and emergency surgeons do not perform an accurate physical examination of the carpal bones. The ancient art of history taking, precise physical examination and elucidation of a confident diagnosis is at risk of being replaced with tentative diagnoses and imaging techniques that are expensive and time consuming. We believe that basic anatomical teaching is inadequate.

A polymerase chain reaction based method for the detection of Culex quinquefasciatus (Diptera: culicidae).

Culex quinquefasciatus Say is the major vector of the filarial parasite Wuchereria bancrofti (Cobbold) which causes lymphatic filariasis in humans. A repetitive DNA sequence from the genome of C. quinquefasciatus has been cloned and completely sequenced. The 693 bp cloned fragment had an A+T content of 72%. Dot matrix analysis of the fragment did not reveal any direct or inverted repeats within it. Southern blot analysis using a variety of restriction enzymes appeared to indicate that the cloned fragment was interspersed within the genome with a copy number of approximately 30,000. A search of the GenBank database did not reveal significant homologies to any previously cloned sequences. Although the probe was sensitive enough to detect picogram quantities of DNA, it was not specific for C. quinquefasciatus, as it hybridized with DNA from other mosquito species, Culex pseudovishnui Colless, Culex gelidus Theobald, Culex tritaeniorhynchus Giles, Anopheles vagus Dönitz and Mansonia uniformis (Theobald). However PCR primers derived from the cloned sequence, IpC, were found to be specific and amplified only C. quinquefasciatus DNA. The optimized PCR assay was found to be very sensitive and was capable of detecting DNA from all stages of C. quinquefasciatus thus making it an ideal diagnostic tool.

A simple and rapid non-radioactive oligonucleotide based hybridization assay for the detection of Wuchereria bancrofti.

Five biotin labeled oligonucleotides was designed based on a previously cloned and characterized repetitive DNA sequence specific for Wuchereria bancrofti. The oligonucleotide mix (containing five probes) when used in a hybridization assay, detected as little as 100 pg of purified W. bancrofti, microfilarial DNA, a single infective stage larva and a single microfilaria in 50 microl blood sample. A simple protocol was followed for the hybridization assay. Blood samples lysed with sterile distilled water and digested with proteinase K in the presence of a detergent were directly applied on to nylon membranes for dot blot assays. The DNA extract of mosquitos carrying infective stage larvae was eluted through sephadex G-50 minicolumns prior to blotting. The assay was also able to detect DNA extracted from microfilariae infected samples stored over five days at room temperature (28 degrees C). This simple and rapid oligonucleotide hybridization protocol with the highly sensitive chemiluminescent-based detection has significant potential for the development of a field kit to detect W. bancrofti infection.

The significance of low density microfilaraemia in the transmission of Wuchereria bancrofti by Culex (Culex) quinquefasciatus Say in Sri Lanka.

Laboratory-bred Culex quinquefasciatus were fed on carriers with low and moderate densities of microfilariae (mf) of Wuchereria bancrofti. In the first series of experiments, mosquitoes were dissected 12 d after feeding. The percentage of infected mosquitoes and the numbers of larvae per infected mosquito were directly proportional to the mf density at the time of feeding. There was an overall high infection rate and a wide distribution of larvae per individual mosquito at all levels, except for the 4 lowest counts. Of the 4 carriers with counts of 5 mf/ml and less, 3 were capable of infecting Cx quinquefasciatus, giving infection rates of 1.0%, 7.4% and 12.0% respectively. In the second series, some mosquitoes were dissected immediately after feeding and the remainder 12 d later. There was a good correlation between the number of mf ingested and the number of infective larvae per mosquito. The high infection rates in Cx quinquefasciatus when fed on low-density microfilaraemia carriers, and the varying number of larvae in individual mosquitoes, suggest that low-density carriers could be a source of infection. Field studies were also carried out in 3 different area with mf rates of 7.24%, 0.72% and 0.16%, respectively. In the 2 areas with low mf rates, infection rates in mosquitoes were 1.32% and 1.08% respectively. Cx quinquefasciatus fed on a carrier with a residual microfilaraemia of 19 mf/ml following treatment with diethylcarbamazine had an infection rate of 13.8%. These studies suggest that the examination of recently fed house-resting populations of Cx quinquefasciatus could be a sensitive method for measuring the prevalence of mf in the human population.

Significance of coconut husk pits as larval habitats of Culex quinquefasciatus (Say) in the filariasis endemic coastal belt of Sri Lanka.

Extended surveys of coconut husk pits in three districts in a study of vectors of Japanese encephalitis showed that Cx. gelidus constituted 50.9% of the larval material in Panadurra, 77.7% in Allutgama and 75.2% in Talalla. Correspondingly, Cx. quinquefasciatus was 0, 4.1 and 0 percent respectively. A similar survey in Polhena, Matara, a well known filariasis endemic village showed 72.2% Cx. gelidus and 21.2% Cx. quinquefasciatus. Analysis of past records of husk pit surveys from seven other districts gave similar results. The reason for relatively higher breeding of Cx. quinquefasciatus in the husk pits at Polhena, Matara and a suggested vector control strategy are discussed.

The susceptibility of Liberian Culex quinquefasciatus to Wuchereria bancrofti in Sri Lanka.

Strains of Culex quinquefasciatus collected in Liberia showed low susceptibility to Wuchereria bancrofti from Liberian donors. However, when the same mosquito strains were fed on W. bancrofti donors from Sri Lanka they showed equally high susceptibility as Sri Lankan C. quinquefasciatus simultaneously fed on the same donors. A Liberian strain did not respond to selection for refractoriness. Thus the strains of W. bancrofti from Liberia and Sri Lanka differ in their ability to infect specific mosquito strains and it is concluded that Liberian C. quinquefasciatus could not provide genes for use in the construction of a refractory strain intended for the replacement of Sri Lankan vector populations.