Dorsi-flexing osteotomy of first metatarsal (using Orthosolutions Memo-staple)
CPD/CME Points: 1
Dorsiflexion osteotomy of the first ray may be performed in isolation to relieve excess pressure through an overlong or overloaded first ray, to relieve pressure through an overloaded and painful sesamoid bone , or to correct a plantar flexed first ray in a cavus foot.
In cavus foot, the plantar flexed first ray strikes first on loading the forefoot, and causes the foot to roll into varus.
Correction of the first ray in cavus is occassionally performed in isolation, but more commonly is performed in association with other procedures such as lateral displacement calcaneal osteotomy, midfoot correction or triple fusion – with or without corrective tendon transfers.
The operation is simplified by the use of a staple to hold the osteotomy, which allows the osteotomy to be performed within 1 cm of the proximal end of the metatarsal, and with correct technique will provide enough stability for the patient to bear weight and mobilise early. The decision as to how much to dorsiflex the first ray is clinical and cannot be calculated accurately pre-operatively . It is judged clinically during the operation.
Because of this, orthotics shoud always be trialled prior to surgery, and the patients should be aware that orthotics are also often needed to get good results after surgery. The osteotomy will adjust the major deformity, but orthotics are usuall needed to achieve fine adjustment and optimal function.
Author: Mr Paul Cooke FRCS
Institution: The Nuffield Orthopaedic Centre ,Oxford ,UK.