Surgical correction of bunion deformity is designed at relieving pain in the first metatarsal phalangeal joint by restoring the first metatarsal to normal functional position as well as relieving the pressure from the prominent first metatarsal bone.  

The severity of the bunion deformity will influence the type of surgical procedure that your surgeon chooses but most importantly will influence the type of recovery that you as a patient will encounter. The severity of the bunion deformity has more to do with the clinical and radiographic findings rather than the pain that is encountered. Smaller bunion deformities can cause as much pain as larger ones.

The most important radiographic measurement in determining the severity of the bunion is the angle that occurs between the first and second metatarsal bones during a weight bearing x-ray of the foot. Non weight bearing x-rays can never be used to classify the severity of the bunion deformity. Generally the angle between the first and second metatarsal will be within 15 degrees in a mild to moderate deformity and greater than 15 degrees in a severe bunion deformity.

All bunion surgeries require a combination of soft tissue releases and rebalancing with the addition of bony surgery or osteotomies to reposition the first metatarsal into its anatomic position.

Bunion deformities of mild to moderate size are generally corrected surgically by releasing tight soft tissues around the joint as well as cutting the metatarsal head with a saw and moving the metatarsal head to normal position.  The orientation and position of the osteotomy at the first metatarsal head with the addition of screw / pin stabilizes these ostetomies thus allowing weight bearing after surgery.

There are many different names for the “metatarsal head” osteotomies including Chevron, Austin, Modified McBride, Reverdin-Laird to name a few.  They however all typically allow immediate weight bearing after surgery with the use of a “post operative shoe” or removable cast boot (CAM walker). The post operative shoe and CAM walker are used for a period of three to four weeks postoperatively until adequate bone healing has occurred at the osteotomy site.

Bunion deformities of moderate to severe size are generally corrected by the same soft tissue releases around the joint but the severity of the metatarsal angulation requires the osteotomy be performed in the base of the metatarsal. These “metatarsal base” osteotomies due to there relative position in the middle of the foot are considered to be unstable and require a non weight bearing period generally between four and six weeks.

The use of crutches or other non weight bearing assistive devices allow adequate healing of the metatarsal bone. Premature weight bearing can cause a failure of the screws and cause the osteotomy site to separate which will delay or prevent adequate bone healing.

The following examples show the clinical and radiographic differences between “metatarsal head osteotomies and metatarsal base osteotomies

The goals of bunion surgery are to provide pain relief and restore anatomic position of the first metatarsal bone and toe. Patients who have symptoms associated with their bunion deformity prior to surgery tend to be more prepared for the time it takes to recover after surgery. Most patients who have bunion surgery do very well but complications as listed below can occur.