Abstract
Introduction
The standard practice of uncomplicated total ankle replacement (TAR) involves post-operative immobilisation. Periprosthetic fracture is a well-recognised complication following ankle arthroplasty. It occurs predominantly as a stress reaction on the medial tibial metaphysis during the post-operative rehabilitation period. Occasionally it occurs during surgery. We present fractures from a single-centre series of Mobility TARs.
Materials and Methods
We have 133 TARs with 3 to 48 months' follow-up. 28 patients were excluded for the following reasons: other major procedure performed concurrently (osteotomy or tendon transfer), custom prosthesis, revision surgery, fusion conversions, or patients involved in a separate RCT (n = 16). We do not routinely immobilise patients post-operatively but allow partial to full weight-bearing as able. Outcome scores were compared to those without fractures.
Results
105 patients were included in the study. Nine (8.6%) patients sustained a periprosthetic fracture with no history of significant trauma. One of these was intra-operative; this was a posterior tibial fracture noticed on post-operative radiographs. The remainder (n = 8) were tibial metaphyseal stress fractures, all occurring within the first three months, most (n = 6) within six weeks. One occurred on the sixth post-op day and was managed in cast. Seven were asymptomatic at diagnosis and managed non-operatively; one was fixed at three months due to radiological medial migration of the talus and one was fixed at seven months due to progression to symptomatic non-union. The remainder united. Between those with and without fractures, there was no significant difference in age (mean 61.4 vs. 62.1, p = 0.387), diagnosis leading to arthroplasty (OA, RA, PTOA), or outcome scores (12 months: 83 vs. 78, p = 0.237)
Conclusion
Periprosthetic fracture remains a significant complication of total ankle arthroplasty.
However, in our series, they do not lead to increased morbidity or worse outcome scores than patients without fractures and most can be managed non-operatively.
