Serum D-dimer should not be used in the diagnosis of venous thromboembolism within 28 days of total knee replacement surgery
10.1186/s43019-020-00068-x
- Author:
Ethan TONER
1
;
Tobenna OPUTA
;
Heather ROBINSON
;
Olivia MCCABE-ROBINSON
;
Andrew SLOAN
Author Information
1. Trauma & Orthopaedic Department, Royal Victoria Hospital, 274 Grosvenor Rd, Belfast BT12 6BA, UK
- Publication Type:R E S E A R C H A R T I C L E
- From:The Journal of Korean Knee Society
2020;32(4):e49-
- CountryRepublic of Korea
- Language:English
-
Abstract:
Background:Serum D-dimer is frequently used to rule out a diagnosis of venous thromboembolism (VTE), a recognised complication following total knee replacement (TKR). TKR is known to cause a rise in D-dimer levels, reducing its specificity. Previous studies have demonstrated that D-dimer remains elevated within 10 days of TKR and therefore should be avoided. The aim of this study was to determine whether serum D-dimer tests are clinically appropriate in identifying VTE when performed within 28 days of TKR.
Methods:Case notes for patients who had a serum D-dimer test performed for clinically suspected VTE at ≥ 28 days following TKR were retrospectively reviewed for a 6-year period. Demographics, D-dimer result, time after surgery and further radiological investigations were recorded.
Results:Fifty patients underwent D-dimer tests at ≥ 28 days following surgery (median 60 days, range 29–266); 48 of these patients had a positive result. Of these, five had confirmed VTE on radiological investigations. Serum Ddimer was raised in 96% of the patients. Only 10.42% of these patients had confirmed VTE. No patients with negative D-dimers had confirmed VTE.
Conclusions:These findings suggest that serum D-dimer remains raised for at least 28 days and possibly considerably longer following TKR. Serum D-dimer should not be used in patients with clinically suspected VTE within this period because of its unacceptably low specificity of 4.44% and positive predictive value of 10.42%, which can lead to a delay in necessary further radiological investigations, waste of resources and unnecessary exposure to harm.
