It is thought that arthroscopic ankle fusion offers improved outcomes over open fusion in terms of functional outcomes, time to fusion, length of stay and fewer complications. However, there are doubts about whether correction of established severe deformity can be achieved using the arthroscopic approach.
A retrospective review of medical records and radiographs at our hospital identified consecutive tibio-talar ankle fusions between April 2009 and March 2014 with minimum 1 year follow up. Records were scrutinised for type of arthrodesis, demographics, length of stay (LOS), time to fusion (TTF), pre- and postoperative deformity, complications and unplanned procedures. Significant factors in the complication group were then compared, using multivariate binary logistic backward stepwise regression to see if any factors were predictive.
There were 29 open and 50 arthroscopic ankle fusions (2 converted to open). Mean LOS was 1.93 versus 2.52 days (p=0.590). TTF was shorter after arthroscopic fusion 196d versus 146d (p=0.083). Severe deformity (>10°) was correctable to within 5° of neutral in the majority of cases (97% versus 96%, p=0.903). Union occurred in 83% versus 98% (p=0.0134). The open arthrodesis group had 9 (31%) complications (1 death-PE, 1 SPN injury, 5 non-unions, 1 delayed union and 1 wound infection) and 6 (25%) screw removals. The arthroscopic arthrodesis group had 4 (8%) complications (1 non-union, 1 reactivation of osteomyelitis and subsequent BKA, 1 wound infection, 1 delayed union) with 11 (24%) screw removals. After multi-variant regression analysis of all ankle fusions, low BMI was shown to be associated with complications (p=0.064).
Open arthrodesis was associated with a higher rate of complications and a lower rate of fusion. However, there was no significant difference in terms of LOS and ability to correct deformity compared to arthroscopic arthrodesis. Overall, low BMI was also associated with more complications.