Functional outcome of computer-assisted spinal pedicle screw placement: a systematic review and meta-analysis of 23 studies including 5,992 pedicle screws

A number of studies have shown increased accuracy of pedicle screw placement in spine with the help of computer-assisted navigation. The literature is lacking in regard to functional benefit derived from this technique. The aim of this systematic review was to look at the functional outcomes following computer-assisted pedicle screw placement in spine. A 'Dialog Datastar' search was used using optimized search strategy covering the period from 1950 to July 2009; 23 papers were finally included which met our inclusion criteria. We report on a total of 1,288 patients with 5,992 pedicle screws. The comparison of neurological complications in two groups demonstrated an odds ratio of 0.25 (95% CI 0.06, 1.14) in favour of using navigation for pedicle screw insertion (p = 0.07). Comparative trials demonstrated a significant advantage in terms of accuracy of navigation over conventional pedicle screw insertion with a relative risk of 1.12 (95% CI 1.09, 1.15) (p < 0.00001). Navigation does not show statistically significant benefit in reducing neurological complications and there was insufficient data in the literature to infer a conclusion in terms of fusion rate, pain relief and health outcome scores.

Patellar resurfacing in primary total knee replacement: a meta-analysis

BACKGROUND

Treatment of the patella during total knee replacement is an area of continuing debate. We performed a meta-analysis of randomized controlled trials to address the hypothesis that patellar resurfacing in primary total knee replacement improved patient outcome.

METHODS

Randomized controlled trials comparing patellar resurfacing with nonresurfacing in primary total knee replacement were included. The primary outcomes analyzed were knee scores, anterior knee pain, and patient satisfaction. We also investigated the prevalence of complications, revision surgery related specifically to the patellofemoral joint, the infection rate, operative time, and radiographic appearance.

RESULTS

Sixteen randomized controlled trials assessing 3465 knee replacements were eligible; 1710 procedures included patellar resurfacing and 1755 did not. The knee component of the Knee Society Score was significantly higher in the resurfacing group (p = 0.005); however, no significant difference was observed for the function component of the Knee Society Score or for any other reported knee score. Anterior knee pain was reported in 13% of resurfaced knees and in 24% of nonresurfaced knees; this difference was not significant (p = 0.1). Patients were satisfied with the outcome after 485 (90%) of 539 procedures that included patellar resurfacing compared with 488 (89%) of 548 that did not; this difference was not significant. There were ninety-three reported patellofemoral complications in the resurfacing group and 205 in the nonresurfacing group; this difference was significant (p = 0.02) in a random-effect model. The rate of reoperation because of anterior knee pain (p &lt; 0.00001) and the rate of reoperation because of any patellofemoral complication (p = 0.002) were significantly higher in the nonresurfaced group. No differences were found in the analyses of infection rate, operative time, or radiographic appearance.

CONCLUSIONS

Patients who underwent patellar resurfacing experienced anterior knee pain and satisfaction with the arthroplasty procedure that were equivalent to those experienced by patients whose patella was not resurfaced; however, these patients underwent significantly fewer additional surgical procedures. Further long-term follow-up of modern prostheses in randomized studies measuring outcome with a patella-specific score is needed.

A meta-analysis of amputation versus limb salvage in mangled lower limb injuries--the patient perspective

This meta-analysis evaluates the quality of life in post-traumatic amputees in comparison with limb salvage. Studies included in this meta-analysis had a minimum of 24 months of follow-up and used a validated quality-of-life outcome assessment scale (Short Form-36 or Sickness Impact Profile) for physical and psychological outcomes. Two reviewers performed the search and data extraction independent of each other. A total of 214 studies were identified; 11 fulfilled the inclusion criteria; thus, 1138 patients were available for meta-analysis (769 amputees and 369 cases of reconstruction). The meta-analysis demonstrated that lower limb reconstruction is more acceptable psychologically to patients with severe lower limb trauma compared with amputation, even though the physical outcome for both management pathways was more or less the same.

Finite element analysis in spine research

Finite element analysis is a widely accepted tool used in many industries and research activities. It allows new designs to be thoroughly 'tested' before a prototype is even manufactured, components and systems which cannot readily be experimented upon to be examined, and 'diagnostic' investigations to be undertaken. Finite element models are already making an important contribution to our understanding of the spine and its components. Models are being used to reveal the biomechanical function of the spine and its behaviour when healthy, diseased or damaged. They are also providing support in the design and application of spinal instrumentation. The spine is a very complex structure, and many of the models are simplified and idealized because of the complexity and uncertainty in the geometry, material properties and boundary conditions of these problems. This type of modelling simplification is not peculiar to spinal modelling problems. Indeed, the idealization is often a strength when there is such uncertainty and variation between one individual and another, allowing cause-effect relationships to be isolated and fully explored, and the inherent variability of experimental tests to be eliminated. This paper reviews the development of finite element analysis in spinal modelling. It shows how modelling provides a wealth of information on our physiological performance, reduces our dependence on animal and cadaveric experiments and is an invaluable complement to clinical studies. It also leads to the conclusion that, as computing power and software capabilities increase, it is quite conceivable that in the future it will be possible to generate patient-specific models that could be used for patient assessment and even pre- and inter-operative planning.

Patient-specific spine models. Part 1: Finite element analysis of the lumbar intervertebral disc--a material sensitivity study

If patient-specific finite element models of the spine could be developed, they would offer enormous opportunities in the diagnosis and management of back problems. Several generic models have been developed in the past, but there has been very little detailed examination of the sensitivity of these models' characteristics to the input parameters. This relationship must be thoroughly understood if representative patient-specific models are to be realized and used with confidence. In particular, the performance of the intervertebral discs are central to any spine model and need detailed investigation first. A generic non-linear model of an intervertebral disc was developed and subjected to compressive, flexion and torsional loading regimes. The effects of both material and geometric non-linearities were investigated for the three loading schemes and the results compared with experimental data. The basic material properties of the fibres, annulus and nucleus were then varied and the effects on the stiffness, annulus bulge and annulus stresses analysed. The results showed that the non-linear geometry assumption had a significant effect on the compression characteristics, whereas the non-linear material option did not. In contrast, the material non-linearity was more important for the flexural and torsional loading schemes. Thus, the inclusion of non-linear material and geometry analysis options in finite element models of intervertebral discs is necessary to predict in vivo load-deflection characteristics accurately. When the influence of the material properties was examined in detail, it was found that the fibre properties did not have a significant effect on the compressive stiffness of the disc but did affect the flexural and torsional stiffnesses by up to +/-20 per cent. All loading modes were sensitive to the annulus properties with stiffnesses varying by up to +/-16 per cent. The model also revealed that for a particular compressive deformation or flexural or torsional rotation, the disc bulge was not sensitive to any of the material properties over the range of properties considered. The annulus stresses did differ significantly as the material properties were varied (up to 70 per cent under a compressive load and 60 per cent during disc flexion).

HCV iatrogenic and intrafamilial transmission in Greater Cairo, Egypt

OBJECTIVES

To document hepatitis C virus (HCV) intrafamilial transmission and assess its relative importance in comparison to other current modes of transmission in the country with the largest HCV epidemic in the world. HCV intrafamilial transmission was defined as HCV transmission among relatives living in the same household.

DESIGN

Case-control study. Cases were adult patients with acute hepatitis C diagnosed in two 'fever hospitals' of Cairo. Controls were adult patients with acute hepatitis A diagnosed in the same two hospitals, and family members of cases. All consenting household members of cases provided blood for HCV serological and RNA testing. Homology of viral sequences (NS5b region) within households was used to ascertain HCV intrafamilial transmission. Exposures at risk for HCV during the 1-6 months previous to onset of symptoms were assessed in all cases and controls.

RESULTS

From April 2002 to June 2007, 100 cases with acute hepatitis C, and 678 controls (416 household members and 262 patients with acute hepatitis A) were recruited in the study. Factors independently associated with HCV infection and their attributable fractions (AFs) were the following: having had a catheter (OR=5.0, 95% CI=1.4 to 17.8; AF=6.7%), an intravenous perfusion (OR=5.8, 95% CI=2.5 to 13.3; AF=20.1%), stitches (OR=2.0, 95% CI=1.3 to 6.6; AF=10.7%), gum treatment (OR=3.7, 95% CI=1.1 to 11.9; AF=3.8%) and being illiterate (OR=2.4, 95% CI=1.4 to 4.4). Of the 100 cases, 18 had viraemic HCV-infected household members. Three long-married (>15&emsp14;years) couples were infected with virtually identical sequences and none of the three index patients reported any exposure at risk, suggesting HCV intra-familial transmission.

CONCLUSION

While three new HCV infections out of 100 could be linked to intra-familial transmission, parenteral iatrogenic transmission (dental care included) was accountable for 34.6% of these new infections. Thus, the relative contribution of intrafamilial transmission to HCV spread seems to be limited.

Differences among breeds and manifestation of heterosis in AI boar sperm output

A total of 271,547 records of semen collections were utilized to appraise sperm characteristics of 3319 boars belonging to eight breeds: Czech Large White (CLW), Czech Landrace (CLA), Prestice Black-Pied (PBP), Czech Meat Pig (CM), Hampshire (HA), Duroc (DC), Pietrain (PN), Large White (LW), and various crosses of these breeds. The data was collected over 8 years (1990-1997) from insemination stations for boars in the Czech Republic. The assessment of sperm output was based on semen volume, number of total spermatozoa and number of viable spermatozoa. A linear model was used for statistical analysis included fixed effects of breed or crossbred combinations, boar within breed or crossbred combinations, year-season, and linear and quadratic regression on age of boars at collection and on interval between collections. The average semen volume of boars ranged from 161 to 349 ml, number of total spermatozoa from 81x10(9) to 119x10(9) and number of viable spermatozoa from 60x10(9) to 86x10(9). The lowest values were detected in DC while the highest were observed in LW. In general, sperm output significantly differed across breeds and their crossbreeds. The highest heterosis effect for semen volume was 30.6% (HA x PN), for number of total spermatozoa 18.2% (HA x PN) and 10.4% for number of viable spermatozoa (CLA x DC). Sperm output varied with season, including high values in autumn and winter and low ones in spring and summer.

A computer assisted orthopaedic surgical system for distal locking of intramedullary nails

This paper presents a prototype system for computer assisted surgery, the purpose of which is to assist orthopaedic surgeons when performing distal locking of intramedullary nails. This system comprises three components, namely: an Intelligent Image Intensifier, a Trajectory Tactician and an Intelligent Trajectory Guide. The Intelligent Image Intensifier is an X-ray vision system that provides accurate X-ray images. Such images enable the Trajectory Tactician software to analyse the operation site and calculate the trajectory required for a screw to lock an intramedullary nail. This involves the capture of two X-ray images from which are extracted the projections of the nail's edge boundaries and its distal locking holes. Using an analytical mathematical model of the nail, the position and orientation of the nail is determined. The trajectory is then implemented by the surgeon using the Intelligent Trajectory Guide. Evaluation in the laboratory suggests that the system is capable of reliably inserting a locking screw into an intramedullary nail. The rapidity with which this computer assisted method achieves locking should benefit both patient and surgeon by reducing radiation dosage and the length of time required to lock a nail.

Computer assisted orthopaedic surgical system for insertion of distal locking screws in intra-medullary nails: a valid and reliable navigation system

The insertion of distal locking screws is a difficult task in intra-medullary (IM) nailing operations of long bones and contributes a significant proportion to the overall operating time. The current technique to insert these screws uses numerous fluoroscopic images and depends on the skills and expertise of the surgeon. The Computer Assisted Orthopaedic Surgical System (CAOSS) was developed to assist orthopaedic surgeons in these operations. The laboratory based test results for insertion of distal locking screws in IM nailing procedures are presented and discussed in terms of accuracy and as part of the validation process to introduce new CAOS procedures into clinical use. This study shows that CAOSS in IM nailing is robust and reliable. Positional accuracy was shown to be within 0.3 mm and angular accuracy within 0.2 degrees with femoral IM nail. CAOSS was also shown to be very reliable and accurate at different angles of distal screws in fluoroscopic image space.

An evidence-based warfarin management protocol reduces surgical delay in hip fracture patients

Background

Up to 4 % of patients presenting with a hip fracture may be on warfarin at admission. There is little consensus on the timing, dosage or route of vitamin K administration. We aimed to evaluate the impact of a locally developed, evidence-based protocol for perioperative warfarin management on the admission-to-operation time (AOT) in hip fracture patients.

Materials and methods

Clinical and demographic data were collected prospectively for hip fracture patients who were on warfarin at the time of admission (post-protocol group) and compared to a historical control group of patients who were on warfarin before implementation of the protocol (pre-protocol group). Univariate analysis was undertaken to identify any significant differences between the two groups.

Results

Twenty-seven patients in the pre-protocol group (27/616, 4.4 %) and 40 patients in the post-protocol group (4.7 %, 40/855) were on warfarin at admission. There was a significant reduction in the median AOT from 73 h (IQR 46–105) to 37.7 h (IQR 28–45) after implementation of the warfarin protocol (p < 0.001). The proportion of patients operated on within 48 h of admission increased from 30 % (8/27) in the pre-protocol group to 80 % (32/40) in the post-protocol group (p < 0.001). No significant differences in hospital length of stay (p = 0.77) or the postoperative warfarin recommencement time (p = 0.90) were noted between the two groups.

Conclusion

Implementation of a perioperative warfarin management protocol can expedite surgery in hip fracture patients, but did not reduce hospital stay in our cohort, possibly because of a delay in recommencing warfarin in these patients postoperatively.

Level of evidence

Level III.

Acute care of hip fractures in centenarians--do we need more resources?

The centenarian population in England and Wales is the most rapidly increasing age group, yet we have little information as regards their acute hospital stay and delay in surgery after hip fracture. We reviewed the records of 26 centenarians with hip fracture between 2000 and 2007 and compared them to a randomly selected control group of 50 hip fracture patients between the ages of 75 and 85 years. The mean stay in acute orthopaedic wards for centenarians was 20.7 days and for the control group was 14.9 days (p=0.015). Centenarians had a mean delay in surgery of 3.6 days while non-centenarians were operated within a mean of 1.9 days, which was not statistically significant (p=0.241). The longer acute hospital stay in our centenarian cohort would amount to a mean extra cost of pound 2511 per patient.

Recovery of distal hole axis in intramedullary nail trajectory planning

In intramedullary nail (IMN) surgical operations, one of the main efforts for surgeons is to find the axes of two distal holes. Two distal holes on an IMN, which are inside the intramedullary canal of a patient's femur, can only be seen in a lateral X-ray view. For the standard surgical procedure, the localization of the distal hole axes is a trial-and-error process which results in a long surgical time and large dose of X-ray exposure. In this paper, an algorithm to derive the three-dimensional position and orientation of the distal hole axis was developed. The algorithm first derives the nail axis through two X-ray images. Then the distal hole axis is calculated through projecting back the hole boundary on the X-ray image from a lateral view to three-dimensional space. A least-squares method is used to determine the centres of the front hole and the back hole through iteration. The algorithm has been tested with real data and it was robust.

Outbreaks of influenza A in nursing homes in Sheffield during the 1997-1998 season: implications for diagnosis and control

Three recent outbreaks of influenza A in nursing and residential homes in Sheffield were characterized by high attack rates among both residents and staff, and a high mortality rate among residents. The epidemiology of the outbreaks was unusual in that all three occurred towards the end of a quiet influenza season, against a generally low level of community activity, and involved strains of influenza that were not included in the current season's vaccine. The outbreak investigation was aided by the use of a novel rapid diagnostic technique. In future the combination of vaccination, surveillance, rapid diagnosis and new antineuraminidase drugs should improve prospects for control of influenza within closed communities.

The cost of outpatient venous thromboembolism prophylaxis following lower limb injuries

This paper reports the cost of outpatient venous thromboembolism (VTE) prophylaxis following 388 injuries of the lower limb requiring immobilisation in our institution, from a total of 7408 new patients presenting between May and November 2011. Prophylaxis was by either self-administered subcutaneous dalteparin (n = 128) or oral dabigatran (n = 260). The mean duration of prophylaxis per patient was 46 days (6 to 168). The total cost (pay and non-pay) for prophylaxis with dalteparin was £107.54 and with dabigatran was £143.99. However, five patients in the dalteparin group required nurse administration (£23 per home visit), increasing the cost of dalteparin to £1142.54 per patient. The annual cost of VTE prophylaxis in a busy trauma clinic treating 12 700 new patients (2010/11), would be £92 526.33 in the context of an income for trauma of £1.82 million, which represents 5.3% of the outpatient tariff. Outpatient prophylaxis in a busy trauma clinic is achievable and affordable in the context of the clinical and financial risks involved.

Synthesis and evaluation for uterotrophic and antiimplantation activities of 2-substituted estradiol derivatives

Two novel series of 2-substituted estradiol derivatives have been synthesized and evaluated for uterotrophic and antiimplantation activities. Among the compounds tested in the rat, 2-acetylestradiol 17 beta-acetate (1), 2-(3'-dimethylamino-1'-propionyl)estradiol 3,17 beta-diacetate (7), 2-(3'-diethylamino-1'-propionyl)estradiol 3,17 beta-diacetate (8), 2-(3'-piperidino-1'-propionyl)estradiol 3,17 beta-diacetate (9), 1'-(2-estradiol 3,17 beta-diacetate-3'-diethylaminopropionyl thiosemicarbazone (12), and 1'-(2-estradiol 3,17 beta-diacetate)-3'-morpholinopropionyl thiosemicarbazone (14) displayed estrogenic activity. At dosages of 4 microliters/rat/day, none of the tested compounds elicited antiimplantation activity. All compounds shared a similar characteristic: nuclear substitution at the C-2 position of the steroid nucleus, a property previously thought to be markedly inhibitory for estrogenic activity.

Day case treatment of delayed union of fracture of the shaft of the tibia with an external fixator

We report six cases of delayed union of fractures of the shaft of the tibia treated by the application of an external fixator on a day case basis. All fractures united within 12 weeks.

Change detection for Lake Burullus, Egypt using remote sensing and GIS approaches

Lake Burullus is the second largest natural coastal lake in Egypt. It has an economic importance for fish yield. However, several anthropogenic activities such as industrial, agriculture, and reclamation activities lead to a deterioration of its water quality and a decrease of the water body area of the lake. This study aims to detect the spatiotemporal changes of Lake Burullus in the period 1972-2015 using 12 Landsat {(1,3-MSS), (4,5-TM), and (7-ETM+)} imageries and water indices approach. To extract water feature from imageries, the Normalized Difference Water Index (NDWI) and the Water Ratio Index (WRI) were applied. The NDWI was applied to the MSS imageries. For other TM and ETM+ imageries, the WRI was applied. Obtained results show a significant decrease in the water area of the Lake Burullus, where it lost about (49%) of its surface area during the period from the year 1972 to the year 2015. A rapid decrease in the lake surface area was noticed through the period from 1972 to 1984. A prediction model was built depending on the calculated water area of the lake. Finally, the multi-temporal maps of the lake surface area are overlaid to produce a map for the changes of the lake surface area using Geographic Information System (GIS).

Cloning of genomic and cDNA for mouse isovaleryl-CoA dehydrogenase (IVD) and evolutionary comparison to other known IVDs

Isovaleryl-CoA dehydrogenase (IVD) is an intramitochondrial homotetrameric flavoenzyme that catalyzes the conversion of isovaleryl-CoA to 3-methylcrotonyl-CoA in the leucine catabolism pathway. Deficiency of IVD in humans causes isovaleric acidemia, which shows tremendous clinical variability for reasons that are unknown. To help better understand this disorder, we have cloned and sequenced the mouse IVD genomic and cDNAs. The mouse IVD gene spans approximately 17 kb and contains 12 coding exons organized identically to the human gene. It maps to mouse chromosome 2 in the area of band 2E4-E5, corresponding to the syntenic region of human chromosome 15. Mouse IVD predicted amino acid sequences are 95.8 and 89.6% identical to that of the rat and human sequences, respectively, with conservation of key functional residues. We have now identified IVD sequences from seven species. Comparison of these sequences shows that the rat and mouse proteins are the most closely related, both of which, in turn, share highest homology to human. All of the mammalian enzymes appear to be more closely related than any of the IVDs on other branches of the phylogram, while the fly and worm IVDs are the most divergent. The invertebrate IVDs are more closely related to the mammalian enzymes than to those from two plant species.

4',17-dioxo-5'H-estra-1(10),4-dieno[3,2-b]furan: synthesis, binding affinity to the estrogen receptor, uterotrophic and antiimplantation activities

4',17-Dioxo-5'H-estra-1(10),4-dieno[3,2-b]furan (3) has been prepared by several routes starting from 2-bromoacetylestrone (2). Performance of the reaction with thiourea at elevated temperature provided compound 3 in good yield. When other reagents such as thiosemicarbazide, morpholine, sodium hydroxide or sodium hydride were treated with 2-bromoacetylestrone at room temperature, the furano derivative 3 was also obtained as the sole product. This new type of structural modification provided an estrogen nucleus deprived of the 3-hydroxyl function which was previously thought to be an essential requisite for binding to the estrogen receptor (ER). When evaluated in vitro for binding to the ER and in vivo for uterotrophic and antifertility activities, the furano derivative 3 was capable of inhibiting [3H]E2 binding by 16% while still eliciting high uterotrophic (99%) and postcoital antiimplantation (100%) activities relative to estradiol.

Quality of operation notes in orthopaedic hip arthroplasty surgery: are we complying with British Orthopaedic Association's guide to good practice?

This retrospective audit evaluates the compliance of our operation notes with the British Orthopaedic Society Primary Hip Arthroplasty 'A guide to good practice' using a 24-data point question (BOA 2006). Ninety-nine notes reviewed, of which 94% had patient identifiers, the surgical team was documented in 92.5%, post-operative instruction in 97%, and prosthesis stability in 97% of cases. Despite high standards, we did not achieve the 100% gold standard. We suggest that increased awareness of the 24-point BOA guideline via education and proformas would help to ensure better practice

Water quality assessment of Lake Burullus, Egypt, utilizing statistical and GIS modeling as environmental hydrology applications

GIS is a very powerful tool for analyzing huge amount of data and connecting them with the geography; moreover, recently, there is great advancement in the field. The main objective of this study is to assess the water quality (WQ) and trophic status (TS) conditions of Lake Burullus, Egypt, using statistical modeling (PCA/FA and CA), WQ index (L-WQI), and trophic status index (Carlson TSI and TRIX) approaches, in addition to using GIS tools for building models able to automatically calculate the various indices and producing color coded maps for the lake. The results indicated that PCA/FA grouped the twenty-four WQ parameters into nine principal components explaining 72.6% of the total variance, domestic, and agriculture pollution were dominant. CA divided the twelve sampling stations into most and least polluted groups. The lake WQ was classified as a "Very Poor," according to L-WQI. Moreover, the results of the Carlson TSI and TRIX indices were coincided and classified the eutrophication levels in the lake as "Hyper-Eutrophic" and "Elevated Trophic," respectively. Based on the results of this study, Lake Burullus needs urgent plans for recovering its WQ. Pre-treatment for its drains' effluents and implementing of a periodical WQ monitoring program are highly recommended.

New facile synthesis of 2-substituted aminobenzimidazoles

In this investigation, the cyclodesulphurization of N-o-aminophenyl-N'-phenylthiourea to produce 2-phenylaminobenzimidazole under the influence of dimethylsulphate was thoroughly studied under different reaction conditions. The mechanism of such reaction was also suggested.

A technique for very high accuracy image intensifier calibration

Accurate characterisation of the image distortion within a fluoroscopic image intensifier is critical if it forms the vision component of an image guided surgical system. By considering non-linear dynamic distortion it is possible to greatly increase the accuracy of the image intensifier, although at the cost of some image quality.