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· DOS Abstracts
No correlation between Bone cyst volume and clinical
symptoms in patients with ankle replacement
Ellen Hamborg-Petersen, Trine Torfing, Janni Jensen, Johnny Frøkjær
Ortopædkirurgisk Afdeling, OUH; Radiologisk Afdeling, OUH
Background:
Periprosthetic bone cysts are a known side effect following a to-
tal ankle replacement (TAR), possibly threatening the long-term survival of the
implant.
Purpose / Aim of Study:
The primary purpose of this retrospective study was
to investigate the correlation between AOFAS score, VAS score, function, age of
implant and periprosthetic cyst volume after TAR.
Materials and Methods:
40 consecutive patients with a Scandinavian Total
Ankle Replacement were seen for a yearly control from 16.09.11-17.05.12.
Forty- one ankles were evaluated, mean age was 61.6 years (40-79) and
mean follow up time was 36 months (3-72). The replacements were radio-
logically evaluated for cysts using Weight- bearing Multi-Planar Reconstructed
Fluoroscopic imaging followed by clinical tests measuring the patients AOFAS
score, VAS score and function. Plots of the residual did not fulfill the normal
distribution. For this reason all analyses were performed using non-parametric
tests (Spearman rho).
Findings / Results:
No statistical significant correlation was found between
the cyst volume and any of the variables: AOFAS score (rho=0.005, p=0.974,
95% CI:-0.307 to 0.316), VAS score (rho=0.137, p=0.399, 95% CI:-0.182 to
0.430), Function (rho=-0.062, p=0.706, 95% CI:-0.371 to 0.258) and ankle
replacement age (rho=0.229, p= 0.149, 95% CI:-0.084 to 0.502).
Conclusions:
No correlation between total cyst volume and AOFAS score, VAS
score and function was found. No correlation between age of TAR and total cyst
volume was found. The significance of periprosthetic cysts in ankles is still not
clear. All patients will be followed with regular controls in the future to observe
further cyst development and aseptic loosening of the prosthesis.
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