title: Comparison of Proximal and Distal Oblique Second Metatarsal Osteotomies with Varying Achilles Tendon Tension: Biomechanical Study in a Cadaver Model.
abstract: BACKGROUND
  The optimal surgery for reducing pressure under the second metatarsal head to treat metatarsalgia is unknown. We tested our hypothesis that a proximal oblique dorsiflexion osteotomy of the second metatarsal would decrease second-metatarsal plantar pressures in a cadaver model with varying Achilles tendon tension. We also tested the plantar pressure effects of two popular techniques of distal oblique osteotomy.
  
  
  METHODS
  Twelve fresh-frozen feet from six cadavers were randomly assigned to either the distal osteotomy group (a classic distal oblique osteotomy followed by a modified distal oblique osteotomy) or proximal metatarsal osteotomy group. Each specimen was tested intact and then after the osteotomy or osteotomies. The feet were loaded with 0, 300, and 600 N of Achilles tendon tension and a 400-N ground reaction force. Plantar pressures were measured by a pressure sensitive mat and analyzed in sections located under each metatarsal.
  
  
  RESULTS
  The proximal metatarsal osteotomy significantly reduced average pressures beneath the second metatarsal head during both 300 and 600 N of Achilles tendon loading by an average of 19.4 and 29.7 kPa, respectively (p < 0.05). The modified distal oblique osteotomy significantly decreased these pressures during 600 N of Achilles tendon loading, by a mean of 20.2 kPa, which was to a lesser extent than the proximal metatarsal osteotomy. Interestingly, the classic distal oblique osteotomy was not found to have significant effects on pressures beneath the second metatarsal head.
  
  
  CONCLUSIONS
  The proximal oblique dorsiflexion metatarsal osteotomy may be the most effective procedure for decreasing plantar pressures under the second metatarsal. The modified distal oblique osteotomy may be the second most effective.
  
  
  CONCLUSIONS
  The findings of this biomechanical study help shed light on which of the common second metatarsal osteotomies are best for decreasing plantar pressures.
authors.affiliation: Penn State Hershey Bone and Joint Institute, 30 Hope Drive, Hershey, PA 17033. E-mail address for U. Aydogan: uaydogan@hmc.psu.edu.
authors.forename: Umur
authors.initials: U
authors.lastname: Aydogan
authors.affiliation: Penn State Hershey Bone and Joint Institute, 30 Hope Drive, Hershey, PA 17033. E-mail address for U. Aydogan: uaydogan@hmc.psu.edu.
authors.forename: Blake
authors.initials: B
authors.lastname: Moore
authors.affiliation: Department of Orthopaedics and Rehabilitation (S.H.A., E.P.R., and G.S.L.) and Department of Public Health Sciences (A.R.K.), Penn State Hershey College of Medicine, 500 University Drive, Hersey, PA 17033. E-mail address for G.S. Lewis: greglewis@hmc.psu.edu.
authors.forename: Seth H
authors.initials: SH
authors.lastname: Andrews
authors.affiliation: Department of Orthopaedics and Rehabilitation (S.H.A., E.P.R., and G.S.L.) and Department of Public Health Sciences (A.R.K.), Penn State Hershey College of Medicine, 500 University Drive, Hersey, PA 17033. E-mail address for G.S. Lewis: greglewis@hmc.psu.edu.
authors.forename: Evan P
authors.initials: EP
authors.lastname: Roush
authors.affiliation: Department of Orthopaedics and Rehabilitation (S.H.A., E.P.R., and G.S.L.) and Department of Public Health Sciences (A.R.K.), Penn State Hershey College of Medicine, 500 University Drive, Hersey, PA 17033. E-mail address for G.S. Lewis: greglewis@hmc.psu.edu.
authors.forename: Allen R
authors.initials: AR
authors.lastname: Kunselman
authors.affiliation: Department of Orthopaedics and Rehabilitation (S.H.A., E.P.R., and G.S.L.) and Department of Public Health Sciences (A.R.K.), Penn State Hershey College of Medicine, 500 University Drive, Hersey, PA 17033. E-mail address for G.S. Lewis: greglewis@hmc.psu.edu.
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Lewis
mesh_terms: D000125:Achilles Tendon / Q000502:physiology*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008297:Male; D008682:Metatarsal Bones / Q000601:surgery*; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods*; D011312:Pressure; D011897:Random Allocation; D016474:Weight-Bearing