Minimally Invasive Bunion Correction
What is a bunion?
A bunion is a common and painful condition affecting the joint at the base of the great toe. Patients usually suffer from pain on the inner aspect of the forefoot right over the bony prominence. Symptoms are usually aggravated by tight shoes and high heels making it harder for patients to ultimately find comfortable shoes. The condition often progresses to create instability of the base of the great toe causing overloads of the bones at the ball of the foot close to the base of the 2nd toe. Progression of the bunion can lead to a collapse of the arch of the foot, hammertoes in the lesser toes, and joint dislocations at the base of the lesser toes.
What is the treatment for bunion?
A bunion is believed to be related to congenital predisposition, shoe wear, and inflammatory diseases. The occurrence of a bunion may be prevented by avoiding excessive use of high-heeled and narrow shoes. Patients with generalized soft tissue laxity and inflammatory arthritis such as rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA) may be more susceptible to the condition.
There is no effective non-surgical treatment that can correct a bunion deformity. Patients may find relief by using shoes with a wide toe box, open-toe shoes, or custom shoes. Silicone pads may be used to minimize soft tissue irritation against the shoe or adjacent toes. Night splints could be tried to minimize symptoms especially at night, but most patients will find it too cumbersome to use it with normal shoes during activities.
Surgical treatments are the only route to correct the deformity and relieve pain as the definitive treatment. It is important to be aware that there are more than 150 techniques, and counting described to correct a bunion deformity. As a rule-of-thumb, when there are always new techniques being invented, it means that the results of previous generations are less than ideal.
What is a minimally invasive bunion correction (MIS)?
Minimally invasive bunion correction (MIS) has been around for decades. It is based on the philosophy that the goals of the surgery can be met with the least amount of collateral damage possible. It is comparable to cardiac catheterization to fix a clogged artery rather than having a formal open thoracotomy. MIS bunion correction has evolved to its 3rd generation where surgical correction is rigidly stabilized using cannulated screws allowing immediate weight-bearing. The cornerstone of the MIS is to use a special bone cutting bur that can allow bone cutting and trimming through 3-mm stab incisions. While the surgery appears attractive, MIS bunion surgery is extremely technical and each surgeon performing it must go through rigorous and multistage training in sawbones and cadavers prior to real patients.
What are the risks and benefits of MIS bunion correction?
Risks: nerve damage, bone shortening, inadequate correction, nonunion, hardware symptoms, transfer metatarsalgia
Benefits: Minimal postoperative pain, Immediate weight-bearing, cosmesis, less scarring, less swelling, faster recovery
What is the recovery after a MIS bunion correction?
Dr. P’s postoperative protocols include immediate weight-bearing using 50% body weight starting on the day of surgery. The patient may achieve this by either using crutches or a walker while putting weight on a provided post-op shoe. Patients will do weight-bearing for light ADLs such as going to the bathrooms or kitchen or short walking inside the house. Some weight-bearing is healthy to the foot as it allows the bone and soft tissue to self-adjust to the flat surface. The amount of walking can be gradually increased and full weight-bearing without an assistive device is encouraged by a month from surgery. The patient can return to normal running or tennis shoes at 6 weeks. Sports and higher impact activities can start at 10 weeks. Patients will not need to do any dressing change themselves but will return to the clinics at 2 and 4 weeks for bunion dressing by Dr. P. Driving can normally resume when the patient stops taking pain medication and can walk comfortably; a trial of driving under family-member supervision is recommended.
What is the question I should ask a surgeon before a MIS bunion correction?
How many MIS bunions have you performed? (This is critical as complications are higher during the learning curve.)
What kind of training has the surgeon completed?
How do you minimize complications such as nerve damage, bone shortening, inadequate correction, nonunion, hardware symptoms, transfer metatarsalgia? (This will minimize adverse events that can lead to poor outcomes.)
Author: Phinit Phisitkul, MD