Analysis of the motion of skeletal structures with the use of markers attached to the skin showed that the skin moves relative to underlying skeletal structures. When working with a 3-D motion-capture system using skin markers, researchers should be aware that the STA could significantly influence their results.

BackgroundPatellar luxation is an orthopedic disorder in which the patella moves out of its normal location within the femoral trochlea of the knee and it can lead to osteoarthritis, lameness, and pain. In dogs it is a heritable trait, with both environmental and genetic factors contributing to the phenotype. The prevalence of patellar luxation in the Dutch Flat-Coated Retriever population is 24%. In this study, we investigated the molecular genetics of the disorder in this population.ResultsGenome-wide association analysis of 15,823 single nucleotide polymorphisms (SNPs) in 45 cases and 40 controls revealed that patellar luxation was significantly associated with a region on chromosome CFA07, and possibly with regions on CFA03, CFA31, and CFA36. The exons of the genes in these regions, 0.5 Mb combined, were analyzed further. These exons from 15 cases and a pooled sample from 15 controls were enriched using custom genomic hybridization arrays and analyzed by massive parallel DNA sequencing. In total 7257 variations were detected. Subsequently, a selection of 144 of these SNPs were genotyped in 95 Flat-Coated Retrievers. Nine SNPs, in eight genes on CFA07 and CFA31, were associated with patellar luxation (P <10-4). Genotyping of these SNPs in samples from a variety of breeds revealed that the disease-associated allele of one synonymous SNP in a pseudogene of FMO6 was unique to Flat-Coated Retrievers.ConclusionGenome-wide association analysis followed by targeted DNA sequencing identified loci on chromosomes 7 and 31 as being involved in patellar luxation in the Flat-Coated Retriever breed.

Although most dogs improved, the prognosis remains guarded. This seems to be independent of age, bilateral involvement, or preoperative OS in these dogs. No relation between medial talar OCD and tarsal hyperextension in stance was found in these dogs.

SummaryElbow dysplasia refers to malformations of the elbow joint, which predominantly occurs in young dogs of large breeds. Labradors are especially affected with fragmented coronoid process and osteochondritis dissecans of the elbow joint that often leads to secondary osteoarthrosis (OA). Mues (16) developed an angle measurement method, presuming that these measurements describe functional aspects of the elbow joints, suitable to characterize the risk of developing OA. The aim of the present studies was to examine whether the morphology of the elbow joint, or the size of the osteophytes in the elbow, is reflected by the measurements. From this study it can be concluded that, in 163 Labradors, the size of the osteophytes, rather then the morphology of the elbow joint, determines the outcome of the angle measurements and thus does not replace the OA-grading system as has been defined by the International Elbow Working Group that is widely in use.