Summary: Foot & Ankle International Podcast — "Changes in Foot Width in Minimally Invasive Bunionectomy"

Release Date: August 27, 2024
Guests: Dr. Charlie Saltzman (Host/Editor, FAI), Dr. Holly Johnson (Senior Author, HSS NYC)

Episode Overview

This episode features a discussion between FAI Editor Dr. Charlie Saltzman and Dr. Holly Johnson, foot and ankle surgeon at Hospital for Special Surgery, New York. The focus is Dr. Johnson's lead paper detailing post-surgical changes in foot width in patients undergoing minimally invasive (MIS) distal Chevron Akin bunionectomy. The conversation explores study findings, clinical implications, patient selection, and evolving best practices.

Key Discussion Points & Insights

1. Study Summary and Rationale

• Dr. Johnson shares her clinical experience:
  • Over 800-900 MIS distal Chevron procedures performed since 2017
  • Noted a subset of patients with midfoot widening after surgery
• Methodology:
  • Retrospective review of patients with good pre- and postoperative radiographs (X-rays, some CT scans)
  • Measured foot width at the medial eminence and mid-shaft before surgery and at 6 months postoperatively
• Findings:
  • Average narrowing at the medial eminence (expected after bunionectomy)
  • Subset of patients (avg. +4mm) developed midfoot widening at the shaft, often at the location of the distal screw
  • Most patients not clinically bothered; a small proportion (5–8%) needed additional surgery for discomfort

"What we found on average was that we were able to narrow the width of the foot at the medial eminence, which is what one would expect after bunion surgery. But we also had a subset of patients that were wider at the midfoot area, approximately. This averaged about 4 millimeters."
— Dr. Holly Johnson (02:58)

2. Clinical Relevance and Patient Complaints

• Nature of patient complaints:
  • Discomfort and difficulty fitting into fashion or formal shoes due to midfoot prominence
  • Not typically an issue for sneakers/athletic footwear
• Interventions:
  • Secondary procedure (remove distal screw, shave bone) yields high satisfaction in affected patients
  • Noted that screw placement/submersion unlikely to be the sole cause—the bone itself is prominent

"There’s a subset of patients that come in after all the swelling’s down, and the foot generally looks very good, but they point to the area on the foot...where they feel a bump or prominence."
— Dr. Holly Johnson (05:27)

3. Mechanism: Why Does This Occur?

• Role of the first TMT joint:
  • Procedure aims to 'lock' the first tarsometatarsal (TMT) joint by shifting the metatarsal shaft medially and head laterally
  • Instability or slippage at TMT joint may result in persistent or increased midfoot width
  • Possible contributions from ligamentous laxity or inter-cuneiform instability

"Despite doing that intraoperatively, over time, whether the ligaments stretch out or whether there’s something else going on, the joint’s not locked. And these are the patients where we’re seeing this widening of the midfoot."
— Dr. Holly Johnson (08:08)

4. Broader Context: Is This Unique to MIS?

• Possible occurrence in other bunion surgeries:
  • Similar midfoot widening/slippage seen in older proximal osteotomy techniques
  • High recurrence rates previously documented in literature (Scott Ellis et al.)
  • Instability can arise if there’s gapping between medial/middle cuneiforms

"I think we see it in the proximal osteotomies...patients sort of slipped out at the first tarsometatarsal joint."
— Dr. Holly Johnson (09:48)

5. Evolving Practice & Patient Selection

• Current clinical algorithm:
  • Careful assessment of hypermobility at first TMT, including subjective exam and radiographic evaluation
  • Plantar gapping on lateral X-rays and medial slippage on AP X-rays are red flags
  • Distal correction (MIS) with counseling: 5–8% risk of secondary procedure, <1% risk of symptomatic recurrence needing revision (Lapidus)
  • Lapidus fusion preferred if instability/hypermobility is detected preoperatively
• Shared decision-making:
  • Patients informed about small but real possibility of further procedures
  • Revision (Lapidus) remains rare and reserved for persistent symptomatic recurrence

"Every single patient I do an MIS or distal correction on, I say there's a 5 to 8% chance we go back...I also counsel patients as well there’s a less than 1% risk that you have enough of a recurrence that you may want to have another surgery."
— Dr. Holly Johnson (12:39)

6. Looking Forward: Future Directions & Research

• Avoiding dogma in bunion correction:
  • Importance of individualized care and comprehensive preoperative evaluation
  • Both distal corrections and Lapidus have a role; selection should be tailored
• Emerging tools:
  • Ongoing research using CT to evaluate TMT morphology for better personalized treatment
  • Goal: Predict and preemptively select ideal procedure for each patient

"I think there’s a lot of dogma around one Bunyan correction being correct or another one being better...I think it’s going to be a mixture of the two. We just—I’m really trying to narrow that algorithm down."
— Dr. Holly Johnson (15:30)

Notable Quotes (with Timestamps)

• On study impact:

  "These are short reports...they become fully referenced in PubMed and are fully downloadable and searchable and can have a lot of impact as I believe this paper will."
  — Dr. Charlie Saltzman (00:29)

• On secondary intervention:

  "It does require a second surgery to go back in, take out the distal screw, shave down the bone to...narrow the foot. And, then it really does solve the problem."
  — Dr. Holly Johnson (06:37)

• On emerging algorithms:

  "We have some exciting CAT scan data...and we’re trying to use that morphology to help guide which procedure will be better for which patient."
  — Dr. Holly Johnson (16:18)

Important Segment Timestamps

• Study Summary & Findings: 01:58–05:11
• Mechanism & Clinical Experience: 05:11–09:34
• Broader Surgical Context: 09:34–11:01
• Patient Selection & Counseling: 11:01–14:40
• Practice Philosophy & Future Research: 15:29–17:14

Conclusion

Dr. Johnson’s study and discussion offer valuable updates on the nuances of foot width changes after MIS bunion surgery. While most patients benefit from a narrower foot, a small subset develop symptomatic midfoot widening, likely due to underlying joint instability rather than hardware prominence. Proactive assessment and patient counseling are key, and ongoing research promises to further refine individualized treatment algorithms.

For more in-depth discussion and future research updates, stay tuned to Foot & Ankle International and upcoming publications from Dr. Johnson’s group.