Developmental dysplasia of the hip (DDH) is a disabling condition that, depending on geography, can afflict between 20% and 80% of patients with end-stage arthritis of the hip. Despite its prevalence, the etiology of this disease remains unknown. DDH is a complex disorder with both environmental and genetic causes. Based on the literature the candidate genes for the disease are HOXB9, collagen type I alpha1, and DLX 3. The purpose of our study was to map and characterize the gene or genes responsible for this disorder by family linkage analysis. We recruited one 18-member, multigeneration affected family to provide cheek swabs and blood samples for isolation of DNA. Amplified DNA underwent a total genome scan using GeneChip Mapping 250 K Assay (Affymetrix, Santa Clara, CA). We observed only one region with a LOD score greater than 1.5: a 4 Mb region on chromosome 17q21.32, yielding a LOD score of 1.82. While a LOD score of 1.82 does not meet the accepted standard for linkage we interpret these data as suggesting the responsible gene could be linked to this region, which includes a cluster of homeobox genes (HOX genes) that are part of the developmental regulatory system providing cells with specific positional identities along the developing joint and spine. Discovering the genetic basis of the disease would be an important step in understanding the etiology of this disabling condition.

Thromboembolic disease is common after orthopaedic surgery. In an effort to minimize the risk of pulmonary embolism and deep vein thrombosis (DVT), anticoagulation administration has become a common practice. Both the American College of Chest Physicians (ACCP) and the American Association of Orthopaedic Surgeons (AAOS) have published guidelines recommending antithrombotic protocols. The ACCP guidelines are excessive and do not adequately evaluate the complications resulting from aggressive anticoagulation. These complications include, but are not limited to, major and minor bleeding events, thrombocytopenia, subsequent periprosthetic infection, and complications with spinal or epidural anesthesia. The AAOS guidelines generated by a group of orthopedic surgeons evaluate the efficacy of various agents in preventing pulmonary embolus and not distal DVT. They differ from the AACP guidelines in some aspects. The AAOS guidelines accept the use of aspirin combined with mechanical compression devices, and low-dose warfarin therapy. We believe that the AAOS guidelines for thromboprophylaxis take into account all risks associated with anticoagulation therapy and may prove to be a safer option for our patients.