Navigational predictors in determining the necessity for collateral ligament release in total knee replacement

The requirement for release of collateral ligaments to achieve a stable, balanced total knee replacement has been reported to arise in about 50% to 100% of procedures. This wide range reflects a lack of standardised quantitative indicators to determine the necessity for a release. Using recent advances in computerised navigation, we describe two navigational predictors which provide quantitative measures that can be used to identify the need for release. The first was the ability to restore the mechanical axis before any bone resection was performed and the second was the discrepancy in the measured medial and lateral joint spaces after the tibial osteotomy, but before any femoral resection.

These predictors showed a significant association with the need for collateral ligament release (p < 0.001). The first predictor using the knee stress test in extension showed a sensitivity of 100% and a specificity of 98% and the second, the difference between medial and lateral gaps in millimetres, a sensitivity of 83% and a specificity of 95%. The use of the two navigational predictors meant that only ten of the 93 patients required collateral ligament release to achieve a stable, neutral knee.

Appendicitis in pregnancy: an ongoing diagnostic dilemma

INTRODUCTION

Appendicitis in pregnancy (AIP) is the most common nonobstetric cause of an acute abdomen requiring surgical intervention. Diagnostic difficulties arising from gestational symptoms compound the risk of foetal loss after negative appendicectomy and exponentially increase the risk to mother and foetus with delay in genuine cases. In this article, we investigate the symptoms and signs of AIP and attempt to identify consistent clinical features and review the role of imaging in diagnosis.

METHOD

MEDLINE and PubMed were searched for case-control studies recording preoperative symptoms/signs suggestive of AIP, as well as appendiceal pathology. Combined likelihood and odds ratios (OR) were created for clinical features across homogenous papers. Papers examining the use of laparoscopy, ultrasound (US), computerized tomography (CT) and magnetic resonance imaging (MRI) were assessed qualitatively.

RESULTS

Seven papers met the inclusion criteria for the analysis of consistent clinical features (450 patients). The only symptoms or signs significantly associated with a diagnosis of appendicitis were nausea (OR: 2.21, 95%CI: 1.34-3.66), vomiting (OR: 0.82-15.6 range) and peritonism (OR: 1.80, 95%CI: 1.06-3.04). US, CT and MRI have all been used to successfully diagnose AIP. Laparoscopic appendicectomy has been safely undertaken in pregnancy.

CONCLUSION

Appendicitis will continue to challenge the diagnostic acumen of surgeons. Whilst useful, consensus regarding the safety of laparoscopy, CT and MRI in pregnancy is yet to be achieved.

Effects of self-management, education and specific exercises, delivered by health professionals, in patients with osteoarthritis of the knee

Background

An education self-management program for people with osteoarthritis (OA) of the knee was designed to be delivered by health professionals, incorporating their knowledge and expertise. Improvement in quality of life, health status and pain in response to this program has previously been demonstrated in an uncontrolled pilot study. To more rigorously test the effectiveness of the program we will undertake a randomised controlled trial of people with OA of the knee offering specific self-administered exercises and education, in accordance with the principles of self-management.

Aim: To determine whether an education self management program for subjects with Osteoarthritis (OA) of the knee (OAK program) implemented by health professionals in a primary health care setting can achieve and maintain clinically meaningful improvements compared standard medical management in a control group.

Methods

The effects of standard medical management will be compared with the effects of the OAK program in a single-blind randomized study.

Participants: 146 male and female participants with established OA knee will be recruited. Volunteers with coexistent inflammatory joint disease or serious co-morbidities will be excluded.

Interventions: Participants will be randomized into either intervention or control groups (delayed start). The intervention group will complete the OA knee program and both groups will be followed for 6 months.

Measurements: Assessments will be at baseline, 8 weeks and 6 months. SF-36, WOMAC and VAS pain questionnaires will be completed. Isometric quadriceps and hamstring strength will be measured using a dynamometer; knee range of movement using a goniometer; and physical function will be determined by a modified timed up and go test. Data will be analysed using repeated measures ANOVA.

Discussion

While there is evidence to support the effectiveness of SM programs for people with hypertension, diabetes and asthma, the evidence available for treatment of arthritis remains equivocal. The aim of this study is to determine the effectiveness of a disease specific self-management program for people with OA knee.

The study design includes all the important features of a clinical experimental study to minimize bias so the results of the study will provide a high level of evidence. People with OA of the knee have identified pain and problems with daily activities as the most important problems associated with their condition. The outcome measures selected specifically address these issues and have demonstrated validity and are responsive within the range of change expected in response to the intervention. Hence the results of the study will reflect their priorities.

The results of the study will provide evidence to guide clinicians and funding bodies seeking to establish priorities regarding the provision of this disease specific program.

Trial registration

ACTR number: 12607000080426

Salvage of the unstable Sauvé-Kapandji procedure: a new technique

The Sauvé-Kapandji procedure has been commonly performed in the setting of posttraumatic osteoarthritis of the distal radioulnar joint. A recognized complication is instability of the proximal ulnar stump, which may occur in up to 33% of cases. Salvage of the failed Sauvé-Kapandji procedure in this setting is difficult and can sometimes involve sacrifice of forearm rotation. We report the results of 3 cases of a new salvage procedure in this setting. The radioulnar pseudarthrosis was taken down; ulnar continuity was restored with an intercalary graft; and forearm rotation was restored with matched hemiresection and interposition arthroplasty at the site of previous radioulnar fusion. Postoperatively, all patients achieved good forearm rotation (mean supination, 60 degrees; mean pronation, 65 degrees), had no symptoms of instability, and were satisfied with the results of the procedure. Disabilities of the Arm, Shoulder and Hand scores improved from preoperative mean of 55 to postoperative mean of 18.

An examination of the planar nature of golf club motion in the swings of experienced players

The golf swing has been modelled as a planar movement, but recent findings suggest that the upper limbs and golf club do not move in a single plane. However, the idea that the club alone can be swung in a single inclined plane has not been investigated mathematically. The aims of this study were to determine whether a single plane could be fitted to club motion, and if this plane varied for different clubs. Ten golfers (handicap 1-5) performed repeated, consistent swings with three clubs (driver, 5-iron, and pitching wedge). The motion of each club during the downswing was fitted to a single plane. The fit of the plane varied between golfers and clubs (r(2) = 0.871-0.995, root mean square residual = 44.9-166.2 mm). Mean angles of the plane to the reference horizontal Z axis (driver: 125.5 degrees , s = 3.0; 5-iron: 117.1 degrees , s = 3.0; wedge: 113.6 degrees , s = 2.7) and target line axis (driver: -7.8 degrees , s = 5.9; 5-iron: -4.9 degrees , s = 5.7; wedge: -5.9 degrees , s = 6.0) were significantly (P < 0.05) different. Further analysis revealed a single plane was more appropriate for some participants than others, but that it might be neither desirable nor possible in some cases.

How evidence based is the management of two common sports injuries in a sports injury clinic?

OBJECTIVES

To examine the diagnosis and management of adults attending a sports injury clinic, to establish to what extent the management of the two most common injuries treated at this clinic is evidence based, and to explore factors that affect management.

METHODS

A retrospective examination of 100 random case notes extracted age, sex, sport, type and site of injury, treatment, and outcome. Systematic literature reviews examined the extent and quality of scientific evidence for the management of the two most commonly presenting injuries. A clinical attachment period and practitioner interviews allowed recognition of factors impinging on management decisions.

RESULTS

Patellofemoral pain syndrome (PFPS; 10% of all injuries) and Achilles tendinopathy (6% of all injuries) were the most commonly presenting injuries. The mean (SD) number of treatments used for PFPS was 2.8 (0.9). The mean number of treatments used for Achilles tendinopathy was 3.7 (1.0). Clinicians reported that personal experience formed the basis of management plans in 44% of PFPS cases and 59% of Achilles tendinopathy cases, and that primary research evidence only accounted for 24% of management plans in PFPS and 14% in Achilles tendinopathy. Practitioners were unaware of literature supporting over 50% of the treatment modalities they used. However, clinicians were often using evidence based treatments, unaware of the supporting research data.

CONCLUSIONS

This study highlights a lack of evidence base, a lack of knowledge of the research evidence, and a lack of management based on the current evidence that is available for these conditions. Practitioners practised evidence based medicine in under 50% of cases.

Process capability measurement of frequent replacement toric soft contact lenses

PURPOSE

Frequent replacement soft contact lenses, and particularly toric soft lenses, require good reproducibility in order to avoid clinical problems arising from manufacturing variations in their parameters. This study assessed the actual and potential process capability of six frequent replacement toric soft lenses in relation to sphere power, cylinder power, cylinder axis, total diameter, back optic zone radius and centre thickness.

METHOD

In total, 1260 lenses consisting of three sphere powers (plano, -3.00 and -6.00 D) were measured for six lens types. Three cylinder powers and six cylinder axes were assessed for each sphere power, except for one lens type where only two cylinder powers were available.

RESULTS

Significant differences in reproducibility were found between the lens types tested. Process capability and optical quality decreased with increasing sphere power for all lenses. Cylinder power process capability tended to be better than that for sphere power. In general, lenses showed adequate reproducibility with those dimensions likely to affect lens fit, namely total diameter, back optic zone radius and centre thickness.

CONCLUSIONS

Process capability was shown to be a useful measure of contact lens reproducibility for comparing toric soft lenses and assessing their potential for use on a frequent replacement basis. The results suggest some need for improvement in manufacturing accuracy and precision.

The rationale for combined chemo/immunotherapy using a Toll-like receptor 3 (TLR3) agonist and tumour-derived exosomes in advanced ovarian cancer

A clinical trial employing an immunotherapeutic approach based on the use of a Toll-like receptor 3 (TLR3) agonist and tumour-derived exosomes carrying tumour-associated antigens is planned in advanced ovarian cancer in conjunction with conventional first line chemotherapy. Most patients with ovarian cancer present with advanced disease and despite high initial response rate to chemotherapy the majority will relapse within 2 years with poor overall survival. Tumour antigen-specific T cells are naturally occurring in ovarian cancer patients and T cell infiltration of the tumour is highly prognostic. Novel immunotherapy to expand and activate tumour antigen-specific T cells combined with adjuvant treatment to overcome tumour-induced immunosuppression is considered to be therapeutically beneficial. The rationale for adopting such a combined approach is discussed here.

Characterisation, mutation detection, and association analysis of alternative promoters and 5' UTRs of the human dopamine D3 receptor gene in schizophrenia

The dopamine D(3) receptor gene (DRD3) is a candidate for a number of psychiatric conditions including schizophrenia, bipolar disorder and alcohol and drug abuse. Previous studies have reported associations between polymorphisms in DRD3 and these disorders, but these findings may have reflected linkage disequilibrium with pathogenic variants that are further upstream. We have isolated and sequenced approximately 9 kb of genomic sequence upstream of the human DRD3 translational start site. Using 5' RACE, we have identified within this region three additional exons and two putative promoter regions which show promoter activity in three different cell lines. A 5' UTR identified only in lymphoblasts is spread over three exons and is 353 bp long. A second 5' UTR, found in adult and fetal brain, lymphocytes, kidney and placenta is spread over two exons and is 516 bp long. A 260-bp sequence within this 9 kb corresponds to a previously reported EST, but corresponding mRNA could not be found in the tissues above. The EST, 5' UTRs and putative promoter regions have been analysed for polymorphisms, revealing 10 single nucleotide polymorphisms, seven of which were tested for association in a large sample of unrelated patients with schizophrenia and matched controls. No associations were observed with schizophrenia. In addition we failed to replicate previous findings of association with homozygosity of the Ser9Gly variant. The results from this study imply that neither the coding nor the regulatory region of DRD3 plays a major role in predisposition to schizophrenia.

A hydrogel material for plastic and reconstructive applications injected into the subcutaneous space of a sheep

Soft tissue reconstruction using tissue-engineered constructs requires the development of materials that are biocompatible and support cell adhesion and growth. The objective of this study was to evaluate the use of macroporous hydrogel fragments that were formed using either unmodified alginate or alginate covalently linked with the fibronectin cell adhesion peptide RGD (alginate-RGD). These materials were injected into the subcutaneous space of adult, domesticated female sheep and harvested for histological comparisons at 1 and 3 months. In addition, the alginate-RGD porous fragments were seeded with autologous sheep preadipocytes isolated from the omentum, and these cell-based constructs were also implanted. The results from this study indicate that both the alginate and alginate-RGD subcutaneous implants supported tissue and vascular ingrowth. Furthermore, at all time points of the experiment, a minimal inflammatory response and capsule formation surrounding the implant were observed. The implanted materials also maintained their sizes over the 3-month study period. In addition, the alginate-RGD fragments supported the adhesion and proliferation of sheep preadipocytes, and adipose tissue was present within the transplant site of these cellular constructs, which was not present within the biomaterial control sites.

Poorly fitting soft lenses affect ocular integrity

PURPOSE

The purpose of this study was to determine whether borderline fitting soft lenses have a greater effect on ocular physiology than well fitting lenses.

METHOD

The study was a retrospective analysis of data from seven soft lens clinical studies. The results of 63 eyes wearing borderline fitting lenses (31 tight and 32 loose fittings) were evaluated and compared with control eyes wearing optimally fitting lenses. Tight and loose lens fittings were defined as those showing tightness on push-up of > or =65% and < or =35%, respectively. An optimally fitting lens was defined as one showing tightness on push-up in the range 45-50% and decentration less than 0.7 mm. Slit lamp findings at the 1-month follow-up visit were compared.

RESULTS

There was a significantly greater level of corneal staining among the tight lens wearing group than the controls (P=0.001); 68% of eyes wearing tight lenses showed staining as compared with 42% of eyes wearing well fitting lenses. There was also a greater level of conjunctival staining among tight lens wearing eyes but no significant difference in bulbar or limbal hyperemia. The loose lens wearing eyes showed a higher level of corneal staining: 69% vs 39% (P=0.04). In addition, the loose lens wearing eyes showed a higher level of bulbar (P=0.03) and limbal hyperemia (P=0.006). From supplementary analysis of 408 lens fittings, the incidence of corneal staining was found to increase with increasing tightness or looseness of fit.

CONCLUSION

The results show that corneal staining and other physiological effects of soft lens wear vary with the quality of lens fit suggesting that practitioners should be less tolerant of sub-optimal fitting soft lenses.

Comparative metabolism of chloroacetamide herbicides and selected metabolites in human and rat liver microsomes

Acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methyl-phenyl)-acetamide], alachlor [N-(methoxymethyl)-2-chloro-N-(2, 6-diethyl-phenyl)acetamide], butachlor [N-(butoxymethyl)-2-chloro-N-(2,6-diethyl-phenyl)acetamide], and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide] are pre-emergent herbicides used in the production of agricultural crops. These herbicides are carcinogenic in rats: acetochlor and alachlor cause tumors in the nasal turbinates, butachlor causes stomach tumors, and metolachlor causes liver tumors. It has been suggested that the carcinogenicity of these compounds involves a complex metabolic activation pathway leading to a DNA-reactive dialkylbenzoquinone imine. Important intermediates in this pathway are 2-chloro-N-(2,6-diethylphenyl)acetamide (CDEPA) produced from alachlor and butachlor and 2-chloro-N-(2-methyl-6-ethylphenyl)acetamide (CMEPA) produced from acetochlor and metolachlor. Subsequent metabolism of CDEPA and CMEPA produces 2,6-diethylaniline (DEA) and 2-methyl-6-ethylaniline (MEA), which are bioactivated through para-hydroxylation and subsequent oxidation to the proposed carcinogenic product dialkylbenzoquinone imine. The current study extends our earlier studies with alachlor and demonstrates that rat liver microsomes metabolize acetochlor and metolachlor to CMEPA (0.065 nmol/min/mg and 0.0133 nmol/min/mg, respectively), whereas human liver microsomes can metabolize only acetochlor to CMEPA (0.023 nmol/min/mg). Butachlor is metabolized to CDEPA to a much greater extent by rat liver microsomes (0.045 nmol/min/mg) than by human liver microsomes (< 0.001 nmol/min/mg). We have determined that both rat and human livers metabolize both CMEPA to MEA (0.308 nmol/min/mg and 0.541 nmol/min/mg, respectively) and CDEPA to DEA (0.350 nmol/min/mg and 0.841 nmol/min/mg, respectively). We have shown that both rat and human liver microsomes metabolize MEA (0.035 nmol/min/mg and 0.069 nmol/min/mg, respectively) and DEA (0.041 nmol/min/mg and 0.040 nmol/min/mg, respectively). We have also shown that the cytochrome P450 isoforms responsible for human metabolism of acetochlor, butachlor, and metolachlor are CYP3A4 and CYP2B6.