Podcast Summary: FAI October 2025 – First Metatarsal Pronation Correction After Fourth-Generation Percutaneous Transverse Osteotomy for Hallux Valgus

Podcast: Foot & Ankle International
Host: Mark Easley (SAGE Publications)
Guests: Dr. Tom Lewis (First Author), Dr. Peter Lam (Senior Author)
Date: October 24, 2025

Overview of the Episode

This Foot & Ankle International episode spotlights the lead paper from the October 2025 issue: “First Metatarsal Pronation Correction After Fourth-Generation Percutaneous Transverse Osteotomy for Hallux Valgus.” Host Mark Easley interviews Dr. Tom Lewis and Dr. Peter Lam, who discuss the evolution and technical details of minimally invasive (MIS) bunion surgery, focusing on clinical and radiographic outcomes—particularly first metatarsal pronation and sesamoid positioning—after fourth-generation percutaneous transverse osteotomy. The conversation offers context for surgeons considering the transition to MIS techniques and highlights the state of evidence in this evolving field.

Key Discussion Points and Insights

1. Study Summary and Major Findings [01:51]

• Study Design: Retrospective single-center study, 51 feet from 34 patients
• Imaging: Weight-bearing CT scans pre- and post-op (~12 months mean follow-up)
• Main Outcomes: Significant improvement in radiographic parameters (including pronation correction) and all clinical foot function measures (MOXFQ, EQ5D, VAS)
• Complication Rate: Low (1.9%)
• Noteworthy: No significant correlation between postoperative outcomes and radiographic pronation parameters

“We didn't find a significant correlation of postoperative outcomes with the radiographic pronation parameters.”
— Dr. Tom Lewis [01:51]

2. Evolution of Percutaneous Osteotomy Techniques [03:03]

• Generational Background:
  • 2nd Gen: Transverse osteotomy with K-wire fixation
  • 3rd Gen: Chevron osteotomy and twin screw fixation (possible instability issues)
  • 4th Gen: Transverse osteotomy avoids certain fixation complications, offering potentially improved stability
• Rationale for 4th Gen: Aims to address fixation and bone removal challenges of prior approaches

“The use of a transverse osteotomy avoids this potential complication.”
— Dr. Peter Lam [03:53]

3. MIS vs. Open Hallux Valgus Surgery [04:12]

• Advantages of MIS:
  • Faster early recovery, less pain, quicker return to footwear
  • Potential for lower long-term recurrence due to bony correction focus
• Recurrent Hallux Valgus: Believed to be less common after MIS, but more long-term data needed

“I do believe the long-term recurrence is less with MIS... because it's predominantly a bony correction…”
— Dr. Tom Lewis [04:12]

4. Technical Pearls: Avoiding Sagittal Translation [05:30]

• Intraoperative Maneuvers:
  • Lifting the metatarsal head upward with fingers, monitoring contour
  • Derotation of the toe so the nail faces upward
  • Importance of reducing medially at the correct point to avoid unwanted plantarization

“The reduction tool has to push the metatarsal head in the mid medial area and not at the dorsomedial head because if that happens then it pushes the head plantarwards…”
— Dr. Peter Lam [05:30]

5. Patient-Reported Outcomes: MOXFQ and EQ5D [07:08]

• MOXFQ: 16-question, foot function/symptom validation (walking/standing, social interaction, pain)
• EQ5D: General health-related QoL, 5 dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression)
• Why These Tools? Validated to compare studies and provide objective, patient-centric outcomes

“What really matters is what patients think, are they happy?”
— Dr. Tom Lewis [07:08]

6. Imaging Techniques for Pronation and Sesamoid Assessment [09:20]

• Weight-bearing CT: Gold standard, especially for complex/revision cases
• Sesamoid Views: Reasonable but variable alternatives where CT isn’t available
• Intraoperative Assessment: Focus on “round sign”, nail position, and big toe alignment over specific sesamoid positioning

“I don't really pay much attention to sesamoid position during surgery.”
— Dr. Peter Lam [09:20]

7. Is Neutral Pronation Essential? [10:31]

• Controversy: Not all pronation equals pathology – some non-hallux valgus patients also have metatarsal pronation
• Personal Perspective: Dr. Lewis is inclined to restore neutral but more data is needed

“I do think that pronation increases the chance of recurrence and... we should try and do is correct it to neutral…”
— Dr. Tom Lewis [10:31]

8. Relationship Between Radiographic Correction and Clinical Outcomes [21:20]

• Evidence: Correction in radiographs does not guarantee improved clinical outcomes at 1 year
• Recurrence: Key marker of surgical failure; lower recurrence with MIS suggested by early 5+ year follow-up, but more data pending
• Long-term Studies: Planned 10-year follow-up underway

“Recurrence is in my opinion, like our failure… and if you look at some of the open studies at... 12, 14 years, the recurrence rate with open surgery is really high, like up to 75%.”
— Dr. Tom Lewis [21:20]

9. When to Consider First TMT Joint Arthrodesis/Lapidus Procedure [19:20]

• Indications: Excessive medial deviation/displacement of 1st metatarsal assessed by squeeze test and X-ray
• Criteria: Distal intermetatarsal space ≥2× first metatarsal width at osteotomy level
• Rationale: Some cases require fusion for adequate correction

“If that space is greater than or equal to twice the width, then I'll consider fusion of the first TMT joint...”
— Dr. Peter Lam [19:20]

10. MIS Surgical Learning Curve and Technique Pearls [23:52]

• Three Tips from Dr. Lewis:
  1. Positioning: Ergonomics and patient set-up are crucial
  2. Fluoroscopy: Accurate X-ray technique essential since visualization is indirect
  3. Mentorship: Find experienced mentors for case discussion and guidance
• Dr. Lam’s Additions: Narrow distal intermetatarsal angle, correct joint orientation, and pronation correction to reduce recurrence
• Case Selection: Start with moderate deformity (not mild/severe) in MIS

“You do need to find a mentor or somebody out there who you can discuss your cases with...”
— Dr. Tom Lewis [23:52]

“If you do all of those three things, you've done the best you can for that particular case to reduce the risk of recurrence.”
— Dr. Peter Lam [25:32]

11. Instrumented vs. Freehand MIS Techniques [23:10]

• MIS Guide Systems: Valuable for beginners; long-term, most experienced surgeons move to freehand
• Principles First: Technology aids are helpful, but understanding fundamentals is key

12. Advice for Newcomers to MIS [29:12]

• Start With: MIS bunionette—more forgiving and simple compared to bunion surgery
• Education: Attend courses and cadaver labs first
• Progression: Gradually move to more complex cases with mentorship

“I would start with bunionettes... it has a very, very low complication rate, and there's only about six steps to it.”
— Dr. Tom Lewis [29:12]

13. Reflections, Cultural Moments, and Lighthearted Exchanges

• Australian Music Favourites: Dr. Lam prefers Cold Chisel and Midnight Oil [11:39].
• The Quirky “Right”: Explored British/Aussie/Irish conversational nuances [17:37].
• Vegemite & Sport: Light banter about Australian experiences [26:59], highlighting the camaraderie among international colleagues.

14. Final Thoughts and Recommendations [31:12, 32:09]

• Training: Importance of cadaver labs, clinical visits, and strong mentorship
• MIS in Orthopaedics: Reflect on integrating MIS into practice as evidence evolves
• Future Direction: Ongoing research will further clarify long-term recurrence rates and optimal techniques

“We’re in a transformative phase of foot and ankle surgery... If the research shows that it’s better for our patients, then I think that we need to look at it.”
— Dr. Tom Lewis [32:09]

“For beginner surgeons, in addition to doing cadaver lab and courses, they should make an effort to visit the surgeon's clinic... and develop a working relationship with a mentor...”
— Dr. Peter Lam [31:12]

Memorable Quotes

• On Evidence and Outcomes:
  “What really matters is what patients think, are they happy?”
  — Tom Lewis [07:08]

• On Surgical Philosophy:
  “If you do all of those three things, you've done the best you can for that particular case to reduce the risk of recurrence.”
  — Peter Lam [25:32]

• On Research Directions:
  “We got ethical approval to look at a 10 year study. So, you know, in the future, hopefully we'll be able to report the outcomes of that.”
  — Tom Lewis [21:20]

Important Timestamps

• Study Summary and Major Findings: [01:51]
• Evolution of MIS Techniques: [03:03]
• MIS vs. Open Surgery: [04:12]
• Technical Pearls for Osteotomy: [05:30]
• Patient Reported Outcomes: [07:08]
• Imaging for Pronation/Sesamoids: [09:20]
• Neutral Pronation Discussion: [10:31]
• When to Fuse the TMT Joint: [19:20]
• Radiographic vs. Clinical Outcomes: [21:20]
• MIS Technique Pearls and Training: [23:52]
• Instrumented vs. Freehand Techniques: [23:10]
• Start MIS With Bunionette: [29:12]
• Final Reflections: [31:12], [32:09]

Conclusion

This episode provides an in-depth look at the technical, clinical, and philosophical underpinnings of the latest MIS techniques for hallux valgus, underscoring the value of patient-centered outcomes, thoughtful surgical technique, mentorship, and the pursuit of robust evidence to guide best practices. Both surgeons advocate for open-mindedness and continued learning as the field shifts toward minimally invasive care.

For further reading, consult the October 2025 FAI publication and referenced studies by Drs. Lewis, Lam, and colleagues.