Hallux valgus : mise au point sur l’analyse radiographique et la planification opératoire

The management of hallux valgus (bunions) has seen significant changes over the last 20 years. The first stage, in the early 1990s, saw the introduction of the scarf osteotomy, allowing the reduction of the metatarsus varus, derotation of the epiphysis and a shortening. The second stage, in 2002, was the SOFCOT round table, emphasising the importance of the DMAA and its radiological evaluation. Alongside this, GRECMIP brought experience in percutaneous surgery to France, through the experience of Ischam and De Prado. Surgical planning finally became reproducible, with the aim of recentering the M1 head under the sesamoids, shortening of the 1st ray in cases of articular incongruity of the MP of the hallux or an oversized hallux and correction of the DMAA. The pre- and intraoperative use of the DM2AA angle allows the calculation of the derotation to be applied to the distal articular surface of the M1. When it comes to the choice of treatment, this is guided by the patient??s radiographic analysis, functional problems and co-morbidity. The choice of final treatment is not restricted to a typical operation to treat all types of hallux valgus. A metatarsus varus below 20° allows surgery with an osteotomy site that can depend on the preferences of the surgeon. However, a metatarsus varus greater than 20° can only be reduced by osteotomy of the base (or Lapidus procedure) with intraoperative verification of the new DM2AA. A non-reduced DM2AA means considering an additional distal osteotomy of the M1. Finally, percutaneous surgery must be restricted to specific cases: a congenital hallux with a metatarsus varus below 16°. Its extension can be achieved by experienced surgeons who are able, using forceps, to increase the translation capacity of percutaneous osteotomies.