Mathematical model for pre-operative planning of linear and closing-wedge metatarsal osteotomies for the correction of hallux valgus

  • F. Bettazzoni
  • A. LeardiniEmail author
  • V. Parenti-Castelli
  • S. Giannini


First-metatarsal osteotomy is performed for an abnormal intermetatarsal angle and severe hallux valgus deformity. The metatarsal head is slid along the osteotomy and fixed with a Kirschner wire to achieve angular and linear realignment with respect to the other metatarsals. When reduction of joint subluxation is also sought, a bone wedge is removed. A mathematical model and a corresponding computer-based tool were developed for pre-operative planning of the optimum surgical solution. Standard intermetatarsal angle correction, head-to-sesamoids re-alignment, joint subluxation reduction and metatarsal length adjustment were all pursued. A standard pre-surgical dorso-plantar radiograph of the patient, with an additional metal ball for calculation of X-ray magnification, was necessary to analyse the original and final geometrical configurations. For the first time, expected bone loss and wire diameter were also considered. The angles of bone cuts and the amount of sliding along these cuts were calculated by the model according to the surgical goal. All the resulting geometrical parameters, both in the pre- and planned post- operative configuration, were provided in graphical and tabular form. In a change from former qualitative analysis of radiograms, the surgeon can now enter the operating theatre with a detailed plan of the goal to be achieved.


First metatarsophalangeal joint Hallux valgus Metatarsal osteotomy Preoperative planning Geometrical modelling Radiograph-based measurements 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Aguilar, E. A., Baratta, R. V., andD’ambrosia, R. (1991): ‘Integrating computers into orthopedic research’,Orthopedics,14, pp. 881–885Google Scholar
  2. Bechtold, J. E., andPowless, S. H. (1993): ‘The application of computer graphics in foot and ankle surgical planning and reconstruction’,Clin. Podiatr: Med. Surg.,10, pp. 551–562Google Scholar
  3. Bösch, P., Markowski, H., andRannicher, V. (1990): ‘Technik und erste Ergebnisse der subkutanen distalen Metatarsale-I-Osteomie’,Orthopaedische Praxis,26, pp. 51–56Google Scholar
  4. Brage, M. E., Bennett, C. R., Whitehurst, J. B., Getty, P. J., andToledano, A. (1997): ‘Observer reliability in ankle radiographic measurements’,Foot Ankle Int.,18, pp. 324–329Google Scholar
  5. Coughlin, M. J. (2000): ‘Common causes of pain in the forefoot in adults’,J. Bone Joint Surg. Br.,82, pp. 781–790CrossRefGoogle Scholar
  6. Coughlin, M. J., Saltzman, C. L., andNunley, J. A. 2nd (2002): ‘Angular measurements in the evaluation of hallux valgus deformities: a report of the ad hoc committee of the American Orthopaedic Foot & Ankle Society on angular measurements’,Foot Ankle Int.,23, pp. 68–74Google Scholar
  7. Dahlen, C., andZwipp, H. (2001): ‘Computer-assisted surgical planning. 3-D software for the PC’,Unfallchirurg.,104, pp. 466–479Google Scholar
  8. Feldman, K. A. (1992): ‘The Green-Watermann procedure: geometric analysis and preoperative radiographic template technique’,J. Foot Surg.,31, pp. 182–185Google Scholar
  9. Graves, S. C., Dutkowsky, J. P. andRichardson, E. G. (1993): ‘The Chevron bunionectomy: a trigonometric analysis to predict correction’,Foot Ankle,14, pp. 90–96Google Scholar
  10. Jahss, M. H., Troy, A. I., andKummer, F. (1985): ‘Roentgenographic and mathematical analysis of first metatarsal osteotomies for metatarsus primus varus: a comparative study’,Foot Ankle,5, pp. 280–321Google Scholar
  11. Jahss, M. H. (1991): ‘Disorders of the hallux and the first ray’ inJahss, M. H. (Ed.): ‘Disorders of the foot and ankle’ (WB Saunders Company, Philadelphia, 1991), chap. 39, pp. 943–1174Google Scholar
  12. Kay, D. B., Njus, G., Parrish, W., andTheken, R. (1989): ‘Basilar crescentic osteotomy. A three-dimensional computer simulation’,Orthop. Clin. North. Am.,20, pp. 571–582Google Scholar
  13. Kummer, F. J. (1989): ‘Mathematical analysis of first metatarsal osteotomies’,Foot Ankle,9, pp. 281–289Google Scholar
  14. Laughlin, T. J. (1995): ‘Complications of distal first metatarsal osteotomies’,J. Foot Ankle Surg.,34, pp. 524–531Google Scholar
  15. Loya, K., Guimet, M., andRockett, M. S. (2000): ‘Proximal shortening lesser metatarsal osteotomy: a mathematical-geometric basis’,J. Foot Ankle Surg.,39, pp. 104–113Google Scholar
  16. Marcinko, D. E., Heden, R.I., andMandel, E. (1984): ‘Determination of the intermetatarsal angle reduction following metatarsal head osteotomies’,J. Am. Podiatry Assoc.,74, pp. 65–70Google Scholar
  17. Murphy, S. B., Kijewski, P. K., Millis, M. B., Hall, J. E., Simon, S. R., andChandler, H. P. (1988): ‘The planning of orthopaedic reconstructive surgery using computer-aided simulation and design’,Comput. Med. Imaging Graph.,12, pp. 33–45Google Scholar
  18. O’Toole, R. V., 3rd,Jaramaz, B., DiGioia, A. M., 3rd,Visnic, C. D., andReid, R. H. (1995): ‘Biomechanics for preoperative planning and surgical simulations in orthopaedics’,Comput. Biol. Med.,25, pp. 183–191Google Scholar
  19. Santore, R. F. (1995): ‘Computers for surgical planning of orthopaedic procedures’,Instr. Course Lect.,44, pp. 527–533Google Scholar
  20. Sarrafian, S. K. (1985): ‘A method of predicting the degree of functional correction of the metatarsus primus varus with a distal lateral displacement osteotomy in hallux valgus’,Foot Ankle,5, pp. 322–326Google Scholar
  21. Shechter, D. Z. andDoll, P. J. (1985): ‘Tangential angle to the second axis. A new angle with implications for bunion surgery’,J. Am. Podiatr. Med. Assoc.,75, pp. 505–512Google Scholar
  22. Tanaka, Y., Takakura, Y., Kumai, T., Samoto, N. andTamai, S. (1995): ‘Radiographic analysis of hallux valgus. A two-dimensional coordinate system’,J. Bone Joint Surg. Am.,77, pp. 205–213Google Scholar
  23. Tanaka, Y., Takakura, Y., Sugimoto, K., Kumai, T., Sakamoto, T., andKadono, K. (2000): ‘Precise anatomic configuration changes in the first ray of the hallux valgus foot’,Foot Ankle Int.,21, pp. 651–656Google Scholar
  24. Trepal, M. J. (1989): ‘Hallux valgus and metatarsus adductus: the surgical dilemma’,Clin. Podiatr. Med. Surg.,6, pp. 103–13Google Scholar
  25. Wade, R. H., Kevu, J., andDoyle, J. (1998): ‘Pre-operative planning in orthopaedics: a study of surgeons’ opinions’,Injury,29, pp. 785–786CrossRefGoogle Scholar
  26. Woodle, A. S. (1989): ‘Preoperative planning for hallux valgus bunion surgery: photonics versus templates’,Clin. Podiatr. Med. Surg.,6, pp. 27–45Google Scholar
  27. Zdravkovic, V., andBilic, R. (1990): ‘Computer-assisted preoperative planning (CAPP) in orthopaedic surgery’,Comput. Methods Programs Biomed.,32, pp. 141–146CrossRefGoogle Scholar
  28. Zembsch, A., Trnka, H. J., andRitschl, P. (2000): ‘Correction of hallux valgus. Metatarsal osteotomy versus excision arthroplasty’,Clin. Orthop.,376, pp. 183–194Google Scholar

Copyright information

© IFMBE 2004

Authors and Affiliations

  • F. Bettazzoni
    • 1
  • A. Leardini
    • 2
    Email author
  • V. Parenti-Castelli
    • 1
  • S. Giannini
    • 2
  1. 1.Dipartimento di MeccanicaUniversità di BolognaItaly
  2. 2.Movement Analysis Laboratory, Department of Orthopaedic SurgeryIstituti Ortopedici RizzoliBolognaItaly

Personalised recommendations