MIS Bunion Surgery Notes

Introduction

• Dr. Wigley discusses minimally invasive bunion surgery (MIS Bunion).

About Dr. Wigley

• Born and raised in Memphis, Tennessee.
• Undergrad at Dillard University in New Orleans.
• Went to Barry University in South Florida.
• Completed surgical residency at Palmetto General Hospital.
• Private practice focusing on rear foot, forefoot, soft tissue mass, and wound care initially.
• Found a niche in minimally invasive bunion surgery in South Florida.

Overview of MIS Bunion

• The talk will cover the techniques, benefits, and outcomes of the Minnow Vasor Bunion procedure.
• It's an introductory overview for various skill levels.

Bunion Overview (Hallux Valgus)

• Number one foot deformity globally.
• Involves the big toe shifting towards the second digit.
• Causes discomfort, pain, and swelling, especially with certain shoes.
• Fixation techniques vary from no fixation to screws.
• The goal is to perfect bunion correction, with minimally invasive approaches being preferred due to less downtime and smaller scars.

Hallux Valgus Details

• Common deformity of the big toe joint.
• Symptoms include pain, redness, swelling, and shoe-wearing difficulties.
• Causes often include genetics, improper footwear, and inflammatory conditions such as arthritis.

Traditional Bunionectomy vs. Minimally Invasive Surgery

• Dr. Wigley has moved away from traditional open incisions for about 95% of bunion cases.
• Recovery Time: MIS allows patients to return to comfortable shoe gear in 3-4 weeks versus 6-8 weeks with traditional methods.
• Scarring: MIS results in smaller, less visible scars, which is a significant concern for patients in South Florida.
• The primary goal of surgery is to alleviate pain and improve mobility.
• Surgical correction is considered the only effective method for bunion correction.
• Dr. Wigley has performed over 400 bunion surgeries in 11 years.

Patient Experiences with Traditional Procedures

• Persistent swelling lasting almost a year.
• Failed recovery periods.
• Long healing times that restrict activity.
• Reluctance to undergo surgery on the other foot in bilateral cases.

Minimally Invasive Approach Details

• Incision Size: Very small incisions (1-2 millimeters) compared to 4-6 inches with traditional methods.
• Tool Used: 2.2 Shannon burr.
• Cosmetic Outcome: Improved due to minimal scarring.
• Trauma: Less tissue disruption, involving only micro-invasive techniques.
• Recovery: Faster recovery times due to reduced tissue trauma.

MIS Benefits

• Smaller incision reduces tissue trauma, allowing for quicker recovery.
• Patients appreciate faster recovery, often scheduling surgery before holidays for extended recovery time.
• Most patients can return to some type of shoe gear within 21-28 days.

Indications for MIS

• Mild to moderate bunions.
• Early-stage bunions without significant disease progression.
• MIS can stabilize hypermobile first rays by shifting the metatarsal component to a desired position.
• Realistic patient expectations and commitment to postoperative protocol are essential.

Surgical Techniques

• Patient Positioning: Supine with foot hanging off the bed to allow use of mini C-arm or C-arm apparatus without obstructions.
• Bur Osteotomy: Using a 2.2 Shannon burr.
• First Metatarsal Surgery: Placing surgery in the medullary canal to shift about 90% of the metatarsal head for correction.
• Fixation: Moving from K-wires to cortical and cancellous screws for compression, transversing the base of the first metatarsal towards the lateral sesamoid.
• The choice of fixation method depends on surgeon preference.

Postoperative Period

• Immediate weight-bearing on the third day with a postoperative shoe is common.
• Micromotion aids bone callus formation and reduces swelling.
• Less swelling reduces complications.
• The choice between a surgical boot and a cam walker depends on patient compliance.
• Proper wound care and weekly check-ups for the first 3-4 weeks, followed by a final follow-up at week 6 or 7.
• Transition to normal tennis shoes for comfort around week four, with expected dorsiflexion of the first metatarsal.

Case Examples

• Example of minimally invasive surgery correcting a moderate bunion (22-26 degrees) to a near-zero degree intermetatarsal angle.
• Early career techniques involved landing two parallel screws.
• Incision healed in about two weeks with minimal swelling.

Recapping Benefits of MIS

• Pain reduction
• Faster recovery time
• High patient satisfaction leading to referrals
• Cosmetically appealing results due to invisible scars can cause jealousy among those with traditional bunionectomy scars

Outcomes

• Evidence based on randomized control studies, retrospective analyses, and meta-analyses, with studies being relatively recent (within the last seven years).
• Dr. Wigley uses MIS for 90-95% of bunion surgeries due to the demographics he serves.

Overcoming the Learning Curve

• Mastery requires dedicated training and practice.
• Practicing dexterity using blocks to perfect cuts can be beneficial.
• Fluoroscopy is essential for precision, with a skilled technician being crucial.

Personal Methods

• Landing two screws parallel to each other, aiming for the lateral sesamoid.
• Achieving nearly 100% shifts.
• Patients are very satisfied with the outcomes.

Q&A Section

• Screw Diameters and Lengths:
  • Shooting from the base of the first metatarsal to the lateral sesamoid:
    • $54 \text{mm}$ screw from the base of the first with $$ correction to the lateral sesamoid.
    • For a traditional two-screw technique, use 44 mm to 36 mm screws depending on the parallel offset.
    • Lateral screw is usually $44 \text{mm}$, with a $4 \text{mm}$ to $6 \text{mm}$ decrease from the medial screw.
  • Using a $4.0$ diameter on nearly all screws, rarely using a $3.0$.
• Cost Difference (Open vs. MIS):
  • MIS uses fewer instruments and materials.
  • Savings come from the time spent in the operating room; shorter procedures reduce costs for anesthesia and supplies.
• Patient Selection for MIS:
  • Surgeon discretion is key based on patient compliance and underlying mental elements.
  • Comorbidities, psychiatric clearances, and potential non-adherence to instructions must be considered.
• Intermetatarsal Angle Cut Off:
  • Up until recently, anything in Lapidus territory was a cutoff, requiring a first metatarsal uniform fusion.
  • Now, Dr. Wigley is using a $$ shift to unlock severe metatarsal joints, avoiding the need for fusion.
• Compression in MIS Implants:
  • There's no definitive evidence between compression versus non-compressive implants.
  • AccuTrack screws have a conical depression, allowing for necessary correction that Herbert screws don't, which can lead to blowouts.
• Tool for Pushing Capital Fragment Laterally:
  • Freehand freer down the metrical canal for leverage.
  • Mosquito hemostat down the medullary canal for shifting.
• Frequency of Aiken Alongside Lateral Osteotomy:
  • Around $15 \%$. Releasing the lateral capsule shifts the toe enough to avoid needing an Aiken.
• Jig System Recommendation for Young Surgeons:
  • Yes, to take advantage of readily available technology.
• Learning Curve for Freehand MIS:
  • Around the seventh or eighth procedure, one gains a better feel for the technique.
• Rep Advice for Switching from Herbert to Accutrack Screws:
  • Highlight the need for a smaller incision with Accutrack.
  • Point out the potential for wall blowout with Herbert screws.
  • Emphasize that Accutrack’s conical shape decreases stress rising and blowback.
• Opinion on 3D Printed Patient-Specific Devices
  • Cost is a factor relative to time and patient population.
• Use of Parallel Wire Guide
  • There's a place for them. It's not slim enough right now.
• Final Thoughts:
  • Be fearless and embrace the MIS world.
  • It is stable and results in fewer headaches long term.