In the December 16, 2015 edition of The Journal, Pellegrini et al. present the results from a cohort of 23 patients who had initially undergone ankle arthrodesis and then, due to decreasing function and increasing mid- and hindfoot pain, sought relief via conversion to an ankle arthroplasty. The good news is that this conversion provided meaningful clinical improvement in pain and function, with 87% survival of the implants over the mean 33-month follow-up.
One technical detail the authors recommend is prophylactic fixation of the malleoli as a concomitant procedure, noting that local osteopenia related to arthrodesis make malleoli prone to fracture during insertion of the tibial component. It is difficult to determine if these conversions were necessitated by poor surgical technique during the original arthrodesis, but I suspect in some cases they were. Also, considering the arthritic changes to the mid- and hindfoot joints related to arthrodesis, it is easy to understand that patients would benefit from the takedown of the fusion and return of some ankle motion to diminish the stress on those joints.
Reflecting on the findings from this clinical cohort series has prompted me to change my surgical technique for ankle arthrodesis. Formerly I hemi-sected the lateral malleolus and fixed it to the talus and distal tibia. Now I preserve the distal fibula, ensure removal of all cartilage in the medial and lateral gutters, add bone graft, and provide fixation with cancellous lag screws. This change in technique facilitates takedown of the fusion and conversion to ankle arthroplasty if necessary in the future. In my opinion, the clarion call now for ankle arthrodesis must be “save the fibula!”
Marc Swiontkowski, MD
JBJS Editor-in-Chief
Hemisection of the distal fibula is not meant to increase the likelihood of fusion. It should be meant to bring the distal fibula to the anatomical level in relation to the subtalar joint. For thsi reason, I remove about 1 cm of fibula about 2 cm proximal to the fusion site to accomodate the distal fibula. Only with the fibula on the anatomical level can the subtalar joint and the fibular tendons work without impingment. Impingment at this spot is a relevant factor to unsatisfaction after ankle fusion.
Thank you for your surgical tip on how to position the hemisected fibula for ankle arthrodesis. As for me, based on the manuscript by Pellegrini et al., I will be leaving the fibula intact in the process of performing ankle arthrodesis.
Thank you for reading OrthoBuzz and for your comments.
Marc Swiontkowski, MD
In my time as a professor of orthopaedics at Calcutta medical college in the early eighties, I had to do quite a few ankle arthrodeses. I used Charnley’s method which I learned from him. They all did fairly well. Most of them were bare footed poor labourers.
reference:
K.Klaue, D.Bursic
Der dorsolaterale Zugang zur Arthrodese des oberen Sprunggelenks
The posterolateral Approach to the Ankle for Arthrodesis
Oper Orthop Traumatol 2005 No.4/5:380-391