5th Metatarsal Rotational Osteotomy for Bunionette

Indication

A rotational 5th metatarsal osteotomy (cutting and rotating the bone) is a type of bunionette surgery indicated for patients with a large, painful bunionette deformity that has failed non-operative management. A typical bunionette deformity is associated with a prominent bone (5th metatarsal head) on the outside of the foot and an enlarged angle between the 4th and 5th metatarsal bones.

Procedure

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 hole 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

Recovery requires that the cut bone heal. This usually takes six weeks of protected weight bearing, often in a walker boot, with loading just through the heel only. Sutures are often removed 10 to 14 days after surgery.

Potential Complications

General Complications

This procedure can be subject to the usual potential complications of any surgery including:

• Infection
• Wound healing problems
• DVT
• Pulmonary embolism
• Nerve injuries

Specific Complications

There are some specific complications that can occur with this procedure including:

• 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.
• Recurrence – Although not as common with a rotation osteotomy, the bunionette deformity can recur after inadequate correction.
• Sensory Nerve Injury – 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.

Edited September 18th, 2023

Previously edited by David Oji, MD

sp/9.18.23