A rotational 5th metatarsal osteotomy (cutting and rotating the bone) is indicated for patients with a large, pain bunionette deformity that has failed non-operative management. The deformity is associated with an increased angle between the 4th and 5th metatarsal bones.
A 5th metatarsal osteotomy (bone cut) is performed through an incision on the outside of the foot. The dissection is carried down to the bone. The outside of the bone is identified and an incomplete oblique cut is made ¾ of the way through the bone. A drill is then placed from top to bottom through the bone and a screw is positioned, but not tightened, in this hole. The remainder of the bone cut is then made. After the cut has been made, the far end (distal part) of the 5th metatarsal is rotated inwards towards the 4th metatarsal, reducing the deformity and allowing for the bunionette correction. The screw is then tightened to stabilize this position, which is reviewed under x-ray. With the bone rotated, there is now a prominent area of bone on the outside (laterally). This is cut off and smoothed. The 5th toe is then straightened up through the capsule on the outside of the base of the 5th toe, allowing for improved positioning of this toe.
Recovery requires that the cut bone heal. This usually takes six weeks of protected weight bearing, in a stiff soled shoe with loading through the heel. Wound review is performed at 10 to 14 days post surgery.
- Wound healing problems
- Pulmonary embolism
- Nerve injuries
- There can be a nerve injury to the nerve that supplies the outside of the 5th toe, which can lead to irritation, numbness, or pain in this area.
- Non-union – In some instances, the bones fail to heal together.
- Malunion– The bones healing in an inappropriate position can lead to increased loading on the outside of the forefoot, or it can lead to a less than ideal position of the fifth toe.