Thus, 36 specimens successfully completed the experiment and are reported on in this article. The data files from another 2 specimens became corrupt and unusable after testing was complete. Two of the 40 specimens were excluded after implantation because of poor bone quality. Existing hallux valgus was not a requirement for inclusion into the experiment. Specimens were allocated to testing groups solely based on the order of arrival from the tissue bank with no prior knowledge of the characteristics of the specimens, outside of the eligibility requirements. Only right feet, age 65 years or younger at the time of death, were eligible for the experiment. Two crossing screws (Mini-Monster cannulated screws Paragon 28: Figure 1D). We hypothesized the locked intramedullary devices and the medial plate with crossing screw would better resist plantar gapping. Given that interfragmentary gap and interfragmentary motion can be harmful to the healing process of bone, the goal of this research was to determine the resistance to plantar gapping of 3 modern hallux valgus fixation constructs and compare them to traditional crossing screw fixation under a lengthy cyclic testing protocol. 8 This may lessen the amount of tissue required to bridge the bone fragments, which may lead to faster healing. 7, 12 Compression across the fusion site can promote direct bone healing by reducing the interfragmentary gap and motion. 12, 16 An excessive gap or too much interfragmentary motion can lead to delayed union or nonunion. 12 Indirect fracture healing occurs when there is interfragmentary motion or lack of contact that stimulates the formation of a callus. 12 Contact healing can take place if the gap between the bone fragments is small (less than 0.01 mm) whereas gap healing will take place if the gap is slightly larger (less than 1 mm). 6, 16 Direct fracture healing occurs under the conditions of fracture stability coupled with anatomic alignment. 6 By increasing stability across a fracture site, revascularization and new bone formation can occur. 2, 3, 14 Stable constructs will be crucial in order for early weightbearing to become the new standard of care.īone healing requires a sufficient blood supply and mechanical stability. 14 However, there are encouraging reports that early weightbearing can be achieved following first TMT arthrodesis. 2, 13 Lengthy periods of nonweightbearing are commonly associated with postoperative complications. Historically, standard postoperative care following first tarsometatarsal (TMT) arthrodesis generally involved a prolonged period of nonweightbearing of approximately 6-8 weeks.
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