Targeted computerised tomography scanning of the ankle   syndesmosis with low dose radiation exposure.
OBJECTIVE
To devise a new protocol for targeted CTscanning of the distal tibiofibular syndesmosis with minimal radiation exposure to patients. We also aimed to correlate the reduction of the syndesmosis as seen on CT scans with the functional outcome of patients.


METHODS
Prospective study. Forty adults undergoing surgical stabilisation of an acute distal tibiofibular syndesmosis injury were recruited. A targeted five-cut computerised tomography scan protocol was developed. The radiation exposure to the patient with this protocol was only 0.002 mSv. Scans were performed 12 weeks after surgery. The contralateral ankle of every patient was used as a control to determine the accuracy of the reduction of the syndesmosis for that individual patient. American Orthopaedic Foot and Ankle Society (AOFAS) scores were obtained at a minimum of 1 year after surgery.


RESULTS
After considering the exclusions, 36 patients formed the study group. A wide variation was observed in the anatomy of the normal syndesmosis. If we considered a difference of more than 2 mm between the normal and injured syndesmosis relationship as significant, 15 (41.6 %) of our patients had a significant difference between the injured and normal sides. AOFAS scores were available for 13 of these patients and were good to excellent in 11(84.6 %).


CONCLUSIONS
Our study describes a reliable new CT scanning technique for the distal tibiofibular syndesmosis using only five cuts and a low-radiation-dose protocol. Clinical correlation of the findings on the scan with functional outcomes suggests that routine post-operative CT of the syndesmosis is probably not justified.
Rahul
R
Kotwal
Narendra
N
Rath
Vishal
V
Paringe
Sandeep
S
Hemmadi
Rhys
R
Thomas
Kath
K
Lyons
D000328:Adult; D000368:Aged; D064386:Ankle Fractures / Q000000981:diagnostic imaging* / Q000601:surgery*; D000843:Ankle Joint / Q000000981:diagnostic imaging*; D001175:Arthrography / Q000379:methods*; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis / Q000517:prevention & control*; D011835:Radiation Protection / Q000379:methods; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome