Abstract
Purpose: Results of basal metatarsal osteotomy are generally unpredictable. We studied the very oblique BRT osteotomy with preservation of the proximal hinge and fixation using a threaded-head screw. We now use this technique as a routine procedure.
Material: From 1999 to 2000, 125 metatarsal osteotomies were performed on 93 feet in 77 patients (mean age 55 years). Indications were metatarsalgia alone in 34 feet, associated with another osteotomy for 21 feet, iatrogenic for 18 feet, and anterior pes cavus for 20 feet.
Method: The incision was dorsal (3 medial metatarsals) or medial for M1 or lateral for M5. The osteotomy was very oblique (60°), with removal of a thin wedge (max 3 mm) except for M1 or in case of pes cavus. The proximoplantar hinge was carefully preserved. The osteotomy was limited to the strict clinical needs and determined on the false lateral view. All patients were reviewed at six months and one year after surgery (mean follow-up 11 months).
Results: The fixation was solid allowing weight bearing at 15 days. Metatarso-phalangeal motion was preserved. There was no secondary displacement but there were three cases with a ruptured hinge due to an insufficiently oblique osteotomy. At last follow-up there has been no transfer to neighbouring rows. For the pes cavus cases, the M1 osteotomy was associated with osteotomy of one or several lateral metatarsals in 13/20 feet in order to further raise the first metatarsal without risk of transfer metatarsalgia.
Discussion: The BRT osteotomy provides an unprecedented reliability for proximal osteotomy with elevation of the metatarsus. It is highly dependent however on clinical assessment, as for any basal osteotomy, although the false lateral view is quite useful. Excessive dorsal elevation must be avoided; secondary elevation is avoided due to the absence of secondary displacement. This osteotomy can be performed easily on all five metatarsals for pes cavus. It is often associated with distal treatment of claw toes. Its association with calcaneum osteotomy is useful for extra-articular treatment of pes cavus to preserve long-term function.
Conclusion: For the two indications metatarsalgia and pes cavus, the BRT osteotomy with elevation of the base is easy to perform, prevents secondary displacement, is precise, and preserves joint function. Precision depends almost totally on clinical evaluation. Results have been very encouraging. Finally, this osteotomy, which involves elevation of the base alone, is complementary to the Weil osteotomy which has specific indications for longitudinal harmonisation of the metatarsus.
The abstracts were prepared by Pr. Jean-Pierre Courpied (General Secretary). Correspondence should be addressed to him at SOFCOT, 56 rue Boissonade, 75014 Paris, France
