Detection of fibular torsional deformities after surgery for ankle fractures with a novel CT method.
BACKGROUND
Substantial fibular torsional deformities were detected after surgery for ankle fractures combined with a lesion of the syndesmotic complex using a novel CT analyzing method.


METHODS
In a prospective study, 61 patients with ankle fracture dislocations were treated with trans-syndesmotic screw fixation of the distal tibiofibular joint. Postoperative axial CT scans of both lower legs under standardized leg positioning conditions were made and analyzed with three different methods. Method 1 (M1) used proximal and distal CT planes of the lower leg for detection of the fibular torsional angle, method 2 (M2) considered only the angle at the distal tibiofibular joint, and method 3 (M3) measured the angles between the fibular and tibial tangents at the distal tibiofibular joint. Twenty patients with fibular torsional asymmetries of more than 10 degrees were evaluated clinically 6 to 34 months postoperatively with the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score.


RESULTS
Thirty-five of the 61 patients had torsional side-to-side differences of more than 10 degrees. M1 and M2 showed statistically significant differences compared to M3 (p = 0.001). Validity was controlled by interobserver data, variation coefficients were low for M1 and M2. Clinically, six of 20 patients with torsional differences of more than 10 degrees had excellent results, while seven had good results and seven had moderately functional results. Six of the seven with moderate results had fibular torsional differences of more than 15 degrees, two of the seven patients with good outcomes. Torsional results of M1 and M2 correlated with the AOFAS score (r = -0.506).


CONCLUSIONS
Of the 61 ankle fractures with ruptures of the syndesmotic complex, 25% showed torsional side-to-side differences of more than 10 degrees on proximal and distal CT planes. This CT technique correlated with the AOFAS score and could help determine when early operative revision is indicated.
Vasarhelyi
Attila
A
University of Rostock, Trauma and Reconstructive Surgery, Schillingallee 35, Rostock, D-18055, Germany. attila.vasarhelyi@med.uni-rockstock.de
Lubitz
Jessica
J
Gierer
Philip
P
Gradl
Georg
G
Rösler
Klaus
K
Hopfenmüller
Werner
W
Klaue
Kaj
K
Mittlmeier
Thomas W F
TW
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016512:Ankle Injuries / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D005260:Female; D005360:Fibula / Q000000981:diagnostic imaging* / Q000503:physiopathology; D050723:Fractures, Bone / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012399:Rotation; D014057:Tomography, X-Ray Computed / Q000379:methods*