Orthopaedic Web Links (OWL): a way to find professional orthopaedic information on the internet.

BACKGROUND: Finding useful high-grade professional orthopaedic information on the Internet is often difficult. Orthopaedic Web Links (OWL) is a searchable database of vetted online orthopaedic resources. OWL uses a subject directory (OWL Directory) and a custom search engine (OWL Web) to provide a list of resources. The most effective way to find readily accessible, full text on-subject material suitable for education of an orthopaedic surgeon or trainee has not been defined. QUESTIONS/PURPOSES: We therefore (1) proposed a method for selecting topics and evaluating searches and (2) compared the search results from an orthopaedic-specific directory (OWL Directory), a custom search engine (OWL Web), and standard Google searches. METHODS: A scoring system for evaluation of the search results was developed for standardized comparison. Single words and sets of three words from randomly selected examination questions provided the search strings to compare the three strategies. RESULTS: For single keyword searches, the OWL Directory scored highest (16.4/50) of the three methods. For the three keywords searches, OWL Web had the highest mean score (26.0/50), followed by Google (22.8/50), and the OWL Directory (1.0/50). OWL Web searches had higher scores than Google searches, while returning 800 times fewer search results. CONCLUSION: The OWL Directory of orthopaedic subjects on the Internet provides a simple browsable category structure to find information. The OWL Web search engine scored higher than Google and resulted in a greater proportion of valid, on-subject, and accessible resources in the search results.

Endothelin-1 down-regulates the expression of vascular endothelial growth factor-A associated with osteoprogenitor proliferation and differentiation.

Endothelin-1 (ET-1) is implicated in the signaling between vascular endothelial cells (VECs) and osteoblasts during bone development, remodeling and repair. Vascular endothelial growth factor (VEGF) also plays an important role in these intercellular interactions. Our objectives were to identify which specific VEGF isoforms were produced during osteoblastic proliferation and differentiation and to determine the effects of ET-1 on VEGF mRNA and protein production by osteoblastic cells. Semiquantitative reverse transcription polymerase chain reaction (RT-PCR) and ELISA were used to evaluate VEGF mRNA isoform expression and protein synthesis at different stages of ET-1-induced osteoblastic differentiation in fetal rat calvaria (FRC) osteoblastic cells. Three VEGF mRNA isoforms were identified corresponding to VEGF(120), VEGF(164) and VEGF(188). Predominant isoforms VEGF(120) and VEGF(164) had a bimodal expression that increased in the early proliferation and late mineralization phases. ET-1 stimulated osteoblastic proliferation and differentiation, but surprisingly, ET-1 down-regulated VEGF mRNA and protein expression and sustained the down-regulation over time in long-term cultures. Time course studies showed that ET-1 inhibited VEGF mRNA expression after incubation for 3 h in 7- and 14-day FRC cell cultures. Similarly, ET-1 inhibited VEGF protein secretion by 5.8- and 2.8-fold in 7- and 14-day FRC cells, respectively. VEGF-A protein secretion was inhibited by ET-1 in a dose-dependent manner with a maximal effect at 10(-7) M. This study supports a novel inhibitory role for ET-1 on VEGF synthesis in osteoblastic cells as a feedback mechanism in the temporal and spatial coupling of angiogenesis to bone formation and resorption.

Controversies relating to the management of acromioclavicular joint dislocations.

The aim of this review is to address controversies in the management of dislocations of the acromioclavicular joint. Current evidence suggests that operative rather than non-operative treatment of Rockwood grade III dislocations results in better cosmetic and radiological results, similar functional outcomes and longer time off work. Early surgery results in better functional and radiological outcomes with a reduced risk of infection and loss of reduction compared with delayed surgery. Surgical options include acromioclavicular fixation, coracoclavicular fixation and coracoclavicular ligament reconstruction. Although non-controlled studies report promising results for arthroscopic coracoclavicular fixation, there are no comparative studies with open techniques to draw conclusions about the best surgical approach. Non-rigid coracoclavicular fixation with tendon graft or synthetic materials, or rigid acromioclavicular fixation with a hook plate, is preferable to fixation with coracoclavicular screws owing to significant risks of loosening and breakage. The evidence, although limited, also suggests that anatomical ligament reconstruction with autograft or certain synthetic grafts may have better outcomes than non-anatomical transfer of the coracoacromial ligament. It has been suggested that this is due to better restoration horizontal and vertical stability of the joint. Despite the large number of recently published studies, there remains a lack of high-quality evidence, making it difficult to draw firm conclusions regarding these controversial issues.

Revision of the humeral component for aseptic loosening in arthroplasty of the shoulder.

Between 1976 and 2004, 38 revision arthroplasties (35 patients) were performed for aseptic loosening of the humeral component. The mean interval from primary arthroplasty to revision was 7.1 years (0.4 to 16.6). A total of 35 shoulders (32 patients) were available for review at a mean follow-up of seven years (2 to 19.3). Pre-operatively, 34 patients (97%) had moderate or severe pain; at final follow-up, 29 (83%) had no or only mild pain (p < 0.0001). The mean active abduction improved from 88 degrees to 107 degrees (p < 0.01); and the mean external rotation from 37 degrees to 46 degrees (p = 0.27). Excellent or satisfactory results were achieved in 25 patients (71%) according to the modified Neer rating system. Humeral components were cemented in 29, with ingrowth implants used in nine cases. There were 19 of standard length and 17 were longer (two were custom replacements and are not included). Bone grafting was required for defects in 11 humeri. Only two glenoid components were left unrevised. Intra-operative complications included cement extrusion in eight cases, fracture of the shaft of the humerus is two and of the tuberosity in four. There were four re-operations, one for recurrent humeral loosening, with 89% survival free of re-operations at ten years. Revision surgery for aseptic loosening of the humeral component provides reliable pain relief and modest improvement of movement, although there is a substantial risk of intra-operative complications. Revision to a total shoulder replacement gives better results than to a hemiarthroplasty.