Automatic Classification of Functional Gait Disorders.

This paper proposes a comprehensive investigation of the automatic classification of functional gait disorders (GDs) based solely on ground reaction force (GRF) measurements. The aim of this study is twofold: first, to investigate the suitability of the state-of-the-art GRF parameterization techniques (representations) for the discrimination of functional GDs; and second, to provide a first performance baseline for the automated classification of functional GDs for a large-scale dataset. The utilized database comprises GRF measurements from 279 patients with GDs and data from 161 healthy controls (N). Patients were manually classified into four classes with different functional impairments associated with the "hip", "knee", "ankle", and "calcaneus". Different parameterizations are investigated: GRF parameters, global principal component analysis (PCA) based representations, and a combined representation applying PCA on GRF parameters. The discriminative power of each parameterization for different classes is investigated by linear discriminant analysis. Based on this analysis, two classification experiments are pursued: distinction between healthy and impaired gait (N versus GD) and multiclass classification between healthy gait and all four GD classes. Experiments show promising results and reveal among others that several factors, such as imbalanced class cardinalities and varying numbers of measurement sessions per patient, have a strong impact on the classification accuracy and therefore need to be taken into account. The results represent a promising first step toward the automated classification of GDs and a first performance baseline for future developments in this direction.

Long-term outcome and subjective quality of life after surgical treatment of lower lip cancer.

OBJECTIVES: Squamous cell carcinoma of the lower lip represents a common type of cancer with a favourable prognosis. Different types of defect reconstruction after ablative surgery are described for maintenance of patients' quality of life. MATERIALS AND METHODS: The study retrospectively evaluates the outcome of 105 patients treated for lower lip cancer. Oncological data as well as individual quality of life were investigated. RESULTS: Cervical lymph node metastases rarely occurred (7.6 %) and were correlated to larger-sized tumours (p = 0.041). Only five patients (4.8) died related to the tumour disease, especially after lymph node metastasis and tumour recurrence (p < 0.001). The 5-year rates for recurrence-free, overall and disease-specific survival were 84.5, 61.2 and 93.9 %. Tumour recurrence correlated with a resection margin of less than 0.75 cm (p = 0.089). With view to postoperative quality of life, the modified Bernard-Fries technique showed the most unfavourable results, particularly referring to sensibility, paraesthesia, lip pursing and mouth opening compared to a stair-step and/or Abbe reconstructions. CONCLUSIONS: Squamous cell carcinoma of the lower lip shows a very favourable prognosis. Neck dissection seems often negligible particularly in small tumours. Patients' functional quality of life after lip surgery depends on the size of the primary and the used technique. Stair-step and/or Abbe reconstructions should be preferred to a Bernard-Fries technique in comparable defect sizes. CLINICAL RELEVANCE: Proper treatment of lower lip cancer provides favourable prognosis and preserves patients' functional and aesthetic quality of life.

Genetic susceptibility to chronic otitis media with effusion: candidate gene single nucleotide polymorphisms.

OBJECTIVES/HYPOTHESIS: The genetic factors leading to a predisposition to otitis media are not well understood. The objective of the current study was to develop a tag-single nucleotide polymorphism (SNP) panel to determine if there is an association between candidate gene polymorphisms and the development of chronic otitis media with effusion. STUDY DESIGN: A 1:1 case/control design of 100 cases and 100 controls was used. The study was limited to the chronic otitis media with effusion phenotype to increase the population homogeneity. METHODS: A panel of 192 tag-SNPs was selected. Saliva for DNA extraction was collected from 100 chronic otitis media with effusion cases and 100 controls. After quality control, 100 case and 79 control samples were available for hybridization. Genomic DNA from each subject was hybridized to the SNP probes, and genotypes were generated. Quality control across all samples and SNPs reduced the final SNPs used for analysis to 170. Each SNP was then analyzed for statistical association with chronic otitis media with effusion. RESULTS: Eight SNPs from four genes had an unadjusted P value of <.05 for association with the chronic otitis media with effusion phenotype (TLR4, MUC5B, SMAD2, SMAD4); five of these polymorphisms were in the TLR4 gene. CONCLUSIONS: Even though these results need to be replicated in a novel population, the presence of five SNPs in the TLR4 gene having association with chronic otitis media with effusion in our study population lends evidence for the possible role of this gene in the susceptibility to otitis media.

Micromotion at the fracture site after tibial nailing with four unreamed small-diameter nails--a biomechanical study using a distal tibia fracture model.

BACKGROUND: Intramedullary nailing is the treatment of choice in tibia fractures allowing for closed fracture reduction and internal fixation. Small-diameter nails that preserve the endosteal blood supply act as load-sharing devices after proximal and distal locking. Despite fracture healing is influenced by movements at the fracture gap, no data are available reporting on the micromovements at the fracture site if small-diameter nails were used. METHODS: Using a Sawbone distal tibia fracture model, we assessed offset, elastic, plastic, permanent, and overall deformation at the fracture site for four small-diameter tibia nails (Expert, Synthes, Saluburg, Austria; Connex, ITS Spectromed, Lassnitzhöhe, Austria; Versanail, DePuy, Vienna, Austria; T2, Stryker, Vienna, Austria) after mechanical testing with a servohydraulic material testing machine. Cyclic loading was performed with a sinusoidal load of 700 N (+/-600) for 40,000 cycles representing 6 weeks of full weight bearing. RESULTS: Offset deformation was significantly higher for the Connex nail when compared with other nails (p < 0.001). Regarding elastic deformation, no significant difference was recorded between the implants. Plastic deformation was significantly lower if the Connex nail was used (0.134 [+/-0.053] mm; p < 0.001). Elastic deformation did not exceed 0.7 mm and plastic deformation did not exceed 0.4 mm. Regarding permanent and overall deformation, no significant difference between the implants was recorded. CONCLUSIONS: Considerable deformation at the fracture gap can be assumed even after partial weight bearing with 100 N. Despite comparable material properties, differences in axial micromotion were recorded among the nail types used in this series. The number of distal locking screws (three or four) did not substantially influence the axial movements at the fracture gap.