Podcast Summary: FAI January 2025 Podcast

Episode Title: Transfibular Total Ankle Arthroplasty: Clinical, Functional, and Radiographic Outcomes and Complications at a Minimum of 5-Year Follow-up
Date: January 10, 2025
Host: Mark Easley (A)
Guest: Dr. Lou Shone (B), Senior Author

Episode Overview

This episode features Dr. Lou Shone, senior author of the lead January 2025 paper in Foot & Ankle International, discussing midterm outcomes of transfibular total ankle arthroplasty (TAA) using a lateral approach. Dr. Shone shares his extensive experience and perspectives on surgical techniques, outcomes, complications, and pearls for success, while also providing historical context and addressing notable limitations of his study. The discussion is interspersed with personal anecdotes, surgical wisdom, and even a bit of musical flair.

Key Discussion Points & Insights

Study Background & Major Findings

[01:59] Dr. Lou Shone:

• Comprehensive review of 83 early TAA cases with ≥5 years follow-up (average 6.3 years)
• Implant survival: 100% (no metal components revised or failed)
• Clinical and radiographic improvements: Multiple patient-reported outcomes and alignment measures
• Most common reoperation: Medial gutter impingement (16.7%)
• Complications:
  • 2 deep infections; both resolved with poly exchange/IV antibiotics, no loosening
  • No cases of: Fibular nonunion/malunion, implant loosening, or subsidence
• Conclusion: The Zimmer TM ankle with lateral (transfibular) approach performs as well or better than other modern implants (previously reported survival rates: 78–98%)

“We had implant survival ship of 100%, no metal components, revised or failed at an average of 6.3 years...” — Lou Shone [02:15]

Rationale for the Lateral (Transfibular) Approach

[04:33] Dr. Lou Shone:

• Relates to trauma experience and management of post-traumatic arthritis
• Analogy: “If you’re trying to attack a castle from the front... every time you try the attack, you fail. Go around the side. That’s one of my philosophies of life.”
• Frequent use of fibular osteotomy in trauma and reconstructive procedures influenced preference
• Approach is particularly suited for cases with fibular malunion and complex deformity correction

“Attack the castle from the side... I was always going from the side, so I stayed at the side.” — Lou Shone [05:56]

Preventing Fibular Nonunion: Surgical Tips

[06:47] Dr. Lou Shone:

• No tourniquet: Promotes living tissue and healing; thanks to mentor Mel Joss
• Trendelenburg position, meticulous hemostasis
• Continuous irrigation: Cool blade during osteotomy (initially via bulb syringes, now IV bag and Fraser tip)
• Bone grafting: Use of iliac crest graft in every case, supplemented by bone marrow aspirate concentrate (BMAC)
• Smoking cessation
• "Love logs": Autograft bone cylinders, sometimes augmented with BMAC or allograft
• Implant fixation: Always plates, preferably locking plates, for precise realignment and possible syndesmotic repair

“My number one trick... don’t use the tourniquet. I put the patient in Trendelenburg... careful hemostasis... I use bmac, bone marrow aspirate concentrate...” [06:50–08:30]

Fixation Techniques: Plate vs. Nail

[09:02] Dr. Lou Shone:

• Prefers plate fixation on every case
• Lag screws for compression when possible, always finished with a plate
• Plates allow better realignment and support for additional fixation (e.g., syndesmotic screw)

“I plate everyone... I’m a plate guy. I like to use the plate because I like to realign it meticulously.” [09:07]

Coronal Plane Deformity Correction from the Lateral Approach

[11:36] Dr. Lou Shone:

• Valgus cases:

  • Fibular osteotomy for lengthening and internal rotation
  • Manual/circular releases (except deltoid), use of distraction (calcaneal pin in frame)
  • Medial side: usually loose deltoid; may use suture/tape or allograft augmentation if needed
  • Possible calcaneal or cotton osteotomy for foot balance

• Varus cases:

  • Fibular osteotomy, possible shortening
  • Milling of tibia for rigid deformities
  • Incision for medial gutter debris/osteophyte excision; superficial deltoid release if necessary

• Powerful correction capability: Corrected deformities up to 25° in this series, up to 35–40° in others

“It’s a very powerful way to correct deformity. I’ve corrected, you know, 35, 40 degrees. Not in this series.” [17:53]

Techniques to Avoid Subsidence & Loosening

[19:10] Dr. Lou Shone:

• Unique implant prep: Uses router to prepare tibia and talus
• Continuous irrigation: To avoid heat necrosis and ensure bone viability
• Minimizing bone resection: Curved cuts remove least amount of bone, maximizing surface area and bone density for ingrowth
• Material choice:
  • Trabecular metal (tantalum): High porosity, excellent bone ingrowth potential, corrosion resistance, high friction
  • Highly cross-linked polyethylene for bearing surface (noted as a late but crucial addition) [33:45]
• Post-op protocol:
  • Full weight bearing on range of motion (ROM) at 2 weeks (not for walking)
  • Ambulatory weight-bearing typically begins at 6 weeks; younger/healthier patients may progress faster
  • Early ROM and "knee bends" to promote function without undue swelling

“Tantalum... is a metal that is highly attractive to bone... bone will grow in it, has a high coefficient of friction, it has a very high boiling and melting point... it’s a metal that is pretty magical.” [21:40]

Functional Outcomes: Tibiotalar vs. Tibiopedal Motion

[26:54] Dr. Lou Shone:

• Emphasizes tibiopedal (entire foot) motion is often functionally more important than isolated tibiotalar movement, as seen in successful arthrodesis patients

“From a functional point of view, that tibiopedal may be more critical for success than actually the range of motion at the tibial talar junction.” [27:17]

Addressing Study Limitations: Missing Data

[29:06] Dr. Lou Shone:

• Many patients lived far away; incomplete data sets due to lack of complete PROMs or radiographs, not true loss to follow-up
• No evidence of data discrepancy between study group and those missing from the dataset
• Active efforts to update and complete data; larger series forthcoming (700+ patients eventually)

“For the patients that we didn’t get... we collect them. And I could assure you that there were no outliers in this cluster. Everything was as is.” [30:22]

Notable Quotes & Memorable Moments

On Choosing the Approach:

“If you’re trying to attack a castle from the front and you keep having trouble... Go around the side. That’s one of my philosophies of life.” — Lou Shone [04:35]

On Managing Nonunion:

“My number one trick… don't use the tourniquet.” — Lou Shone [06:52]

On Bone Ingrowth:

“Tantalum, atomic number 73, is a metal that tantalizes bone.” — Lou Shone [21:40]

On Post-op Protocol:

“Full weight bearing is allowed at two weeks out of the splint. They stand and they are taught to do knee bends...” — Lou Shone [20:40]

On Study Cohort Integrity:

“We didn’t lose them to follow up. We just didn’t have all their data.” — Lou Shone [29:08]

On Surgery vs. Rock Music:

“Even though there might have been 35,000 people in the audience, when I'm operating, [there’s] one patient in the audience and that's my focus.” — Lou Shone [33:00]

Timestamps for Important Segments

• [01:59] Study summary and major results
• [04:33] Rationale for the lateral approach
• [06:47] Preventing fibular nonunion: detailed surgical tricks
• [09:02] Fixation methods: plate vs. nail
• [11:36] Coronal plane deformity correction
• [19:10] Avoiding loosening, subsidence, and details on implant material
• [26:54] Emphasis on tibiopedal motion vs. tibiotalar motion
• [29:06] Handling study limitations and missing data
• [32:06] Fun: Performing at Fenway with the Foo Fighters vs. doing first lateral TAA
• [33:45] Bonus: The role of highly cross-linked polyethylene

Final Thoughts & Closing Advice

• Patient-specific analysis of deformity is key; individualized, mechanically creative solutions are needed.
• The lateral (transfibular) approach, in experienced hands and with meticulous technique, offers robust correction capabilities and excellent medium-term implant survival.
• Advanced implant materials (trabecular metal, highly cross-linked polyethylene) and careful soft tissue/bone handling are critical to success.

“You gotta think what's best for your patient, analyze their deformities and... do very creative mechanical work to get them to a better place.” — Lou Shone [34:21]

For more detail, see the January 2025 issue of Foot & Ankle International and look out for larger cohort follow-ups in future publications.