title: Assessment of ankle and hindfoot stability and joint pressures using a human cadaveric model of a large lateral talar process excision: a biomechanical study.
abstract: Lateral talar process fragment excision may be followed by hindfoot instability and altered biomechanics. There is controversy regarding the ideal fragment size for internal fixation versus excision and a concern that excision of a large fragment may lead to significant instability. The aim of this study was to assess the effect of a simulated large lateral talar process excision on ankle and subtalar joint stability.A custom-made seesaw rig was designed to apply inversion/eversion stress loading on 7 fresh-frozen human cadaveric lower legs and investigate them in pre-excision, 5 cm and 10 cm lateral talar process fragment excision states. Anteroposterior radiographs were taken to assess ankle and subtalar joint tilt and calculate angular change from neutral hindfoot alignment to 10-kg forced inversion/eversion. Ankle joint pressures and contact areas were measured under 30-kg axial load in neutral hindfoot alignment.In comparison to the pre-excision state, no significantly different mediolateral angular change was observed in the subtalar joint after 5 and 10 cm lateral talar process fragment excision in inversion and eversion. With respect to the ankle joint, 10-cm fragment excision produced significantly bigger inversion tibiotalar tilt compared with the pre-excision state, P = .04. No significant change of the ankle joint pressure and contact area was detected after 5 and 10-cm excision in comparison with the pre-excison state.An excision of up to 10 cm of the lateral talar process does not cause a significant instability at the level of the subtalar joint but might be a destabilizing factor at the ankle joint under inversion stress. The latter could be related to extensive soft tissue dissection required for resection.
authors: From the New York Presbyterian - Lower Manhattan Hospital, New York, NY (AS); AO Research Institute Davos, Davos (CW, MB, IZ, DW, ME, MW, JEH, RGR, BG); and Cantonal Hospital Baselland and University Basel, Liestal, Switzerland (KS).
authors: Andrew
authors: A
authors: Sands
authors: Charles
authors: C
authors: White
authors: Michael
authors: M
authors: Blankstein
authors: Ivan
authors: I
authors: Zderic
authors: Dieter
authors: D
authors: Wahl
authors: Manuela
authors: M
authors: Ernst
authors: Markus
authors: M
authors: Windolf
authors: Jennifer E
authors: JE
authors: Hagen
authors: R Geoff
authors: RG
authors: Richards
authors: Karl
authors: K
authors: Stoffel
authors: Boyko
authors: B
authors: Gueorguiev
mesh_terms: D000843:Ankle Joint / Q000502:physiology*; D001696:Biomechanical Phenomena; D006801:Humans; D007593:Joint Instability; D013628:Talus / Q000601:surgery*