Understanding the mechanism behind a bone fracture helps orthopaedic surgeons select the best approach to reduction and fixation. But patients who present emergently and in great pain are often not able to articulate exactly what happened. Furthermore, when the orthopaedic literature describes mechanisms of injury in words, such as “a high-energy abduction and external rotation of the ankle…,” it leaves a lot to the imagination.
The cell-phone video below had the unintended positive consequence of helping the orthopaedic surgeon understand how this ankle injury—a Weber Type C high fibula fracture, with a spiral pattern, a posterior butterfly, and a large posterior malleolus fracture involving 40% of the articular surface—came about.
The injury was treated using a posterolateral approach to the posterior malleolus. Lag screw fixation was followed by posterior plating of the Weber C level fibula fracture. The syndesmosis was found to be intact during intraoperative testing, and the patient is recovering well.
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