Abstract
Objective:
The fabella is the “little bean” sesamoid in the knee that lies within the lateral head of the gastrocnemius adjacent to the lateral femoral condyle. It can articulate and the size and shape can vary. The incidence of fabella is 10-30% [1] of the general population however it has been suggested the incidence is higher in the arthritic knee. The fabella can be associated with pathology post total knee arthroplasty (TKA). The association a fabella and the effect on outcomes following TKA is not clear.
Methods:
A literature review was undertaken to identify scientific literature discussing fabella pathology following TKA. A cohort of Tasmanian patients who have had TKA were reviewed to determine the incidence of fabella. Those patients with a fabella the size was classified as small, medium and large. The change in oxford knee score at 6 months post surgery was compared in each group.
Results:
The literature has reported cases of fabella syndrome, fabella impingement, fabella fracture and common peroneal palsy due to fabella post TKA.
The incidence of fabella in a Tasmanian cohort was approximately 48%. 36% of patients with a fabella were large. The more severe the OA the more likely to have a large fabella. Oxford knee score at 6 months post-surgery for patients with and without a fabella was not different.
Conclusion:
It is good for arthroplasty surgeons not to forget the fabella as a source for potential pathology with arthroplasty. The presence of a large fabella does not affect Oxford knee score outcome following TKA.