No abstract

No abstract

High aseptic loosening rates have been reported in total joint prostheses of the carpometacarpal joint of the thumb, particularly in the trapezial component. The primary fixation of new implants may be tested in cadaver bones, but the anatomy of the pig is in many ways similar to that of the human, so we compared the central carpal bone from the forefoot of 6-month-old pigs, which has a saddle joint surface similar to the trapezium, to the trapezium in patients with carpometacarpal osteoarthritis. The mean (SD) bone mineral density of the 13 pig forefoot bones was 0.88 (0.12) g/cm(2) compared with 0.63 (0.16) g/cm(2) in the 31 human trapeziums. The measured size of the porcine bones was slightly larger than that of the human trapeziums. The similarity in form, size, and bone mineral density means that the central bone of the forefoot of 6-month-old pigs may be used for fixation tests in trapezial implants.

Background Many operators of professional high-speed boats suffer severe, acute, and permanent injuries caused by slamming-induced hull impacts. As the number of professional high-speed boats and their speed capabilities increase, operators are reporting increasing numbers and severity of injuries. However, the actual incidence rate of acute injuries and the prevalence of chronic musculoskeletal disorders are still unknown. Questions/purposes We sought to investigate, among professional high-speed boat operators, (1) the selfreported incidence rate of impact-induced injuries, (2) the most common types of injuries or injury locations, (3) what impact characteristics were reported, and (4) the prevalence of self-reported sick leave, disability, and medical or orthopaedic treatment. Methods This study was an internet-based survey among retired military high-speed boat operators. The survey was given to members of the Combatant Craft Crewman Association online user group (360 members). Participants answered questions on demographics, service branch, service years and capacity, boat type, types of events, injury location, severity, pain, disability, and need for treatment. Values are presented as the mean 6 SD and proportions. Incidence rates are presented as injuries per person-year. A total of 214 Members of one of the author's (JU) family has ownership of Ullman Dynamics, which develops and produces marine suspension seats. JU has no ownership and has not received any payments from Ullman Dynamics. This author certifies no receipt of personal payments or benefits from Ullman Dynamics. One of the authors (RC) is the president of Train Maintain Sustain Group, which provides high-speed boat operations training and expertise in high-speed boat design and performance. This author certifies no receipt of personal payments or benefits, during the study period. RC/TMS Group later commenced consultancy work for Ullman Dynamics in the United States. This author certifies current receipt of payments or benefits of USD 10,000 to USD 100,000 from Ullman Dynamics. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request. Ethical approval for this study was obtained from the Swedish Ethical Review Authority (number 2022-00603-01).