Ankle ORIF Update 2021: Fibular Nails / Medial Malleolus Fixation

 

Fibular Nails

Background

  • Intramedullary implants have been widely used in other long bones but less so in the fibula
  • First case series in the literature in 1986
  • Divided into those that act just to maintain longitudinal alignment, and those that confer additional rotational or axial stability
  • Unlocked nails have largely fallen out of use, as they did not confer rotational or axial stability
  • Most historical studies were level IV evidence and showed great variability between implants
  • More modern designs incorporate locking screws

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Potential Advantages

  • Minimal incision
  • Less soft tissue compromise in high-risk patients
  • Less prominent metalwork, therefore less need for removal

Disadvantages

  • Unable to visualise the syndesmosis during reduction
  • Closed reduction difficult; anatomical reduction often not possible
  • Expensive, potential learning curve, surgical errors due to unfamiliarity

ORIF vs IM fixation

  • Two studies since 2015 – fewer complications with fibula nail
  • Union rate 97.4-100% with locked nail
  • Relatively few soft tissue problems and low revision rate

However, the quality of evidence is lacking, and these devices have largely not been adopted by fellowship-trained F&A surgeons in the UK.  We await long term follow-up from multicentre RCTs.

 

Medial Malleolar Fixation

Pattern of Injury

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Herscovici classification:

A - tip avulsions (anterior colliculus)

B - intermediate

C - level of plafond

D - above plafond (adduction fractures)

 

To fix or not to fix?

  • Single-centre RCT of medial malleolar fracture management when displaced <2mm, with PROMS follow-up to one year; due to finish data collection Feb 2021 – yet to report
  • Single previous RCT: no difference in PROMS but 9% non-union rate in non-operative group

Choice of fixation

  • Tip avulsions (A) should be addressed if the deep deltoid is also involved
  • Avulsion fractures (B/C) should be fixed with one or two screws
  • Type D fractures should be fixed with an anti-glide plate or similar, with screws perpendicular to the fracture line
  • Percutaneous fixation is associated with higher rate of non-union
  • There is no clinical, radiographic or PROMS difference with one vs two screws
  • Consider bi-cortical, fully-threaded fixation in high-risk patients with poor bone stock

Questions:

  • How would you fix an adduction injury with a vertical shear fracture of the medial malleolus?
  • What would be the indications for a fibular nail, according to the current literature?

 

References

Carter TH, Mackenzie SP, Bell KR, et al. Optimizing Long-Term Outcomes and Avoiding Failure With the Fibula Intramedullary Nail. J Orthop Trauma 2019; 33: 189–195

White TO, Bugler KE, Appleton P, et al. A prospective randomised controlled trial of the fibular nail versus standard open reduction and internal fixation for fixation of ankle fractures in elderly patients. Bone Joint J 2016; 98-B: 1248–52

Asloum Y, Bedin B, Roger T, et al. Internal fixation of the fibula in ankle fractures: a prospective, randomized and comparative study: plating versus nailing. Orthop Traumatol Surg Res 2014; 100: S255-9

Carter TH, Oliver WM, Graham C, et al. Medial malleolus: Operative Or Non-operative (MOON) trial protocol - a prospective randomised controlled trial of operative versus non-operative management of associated medial malleolus fractures in unstable fractures of the ankle. Trials 2019; 20: 565