Detecting factors of Syndesmotic injury in Ankle Fx. in radiograph 분당서울대학교병원 최 영

Ankle Fracture Indrect ankle Fx. One of the most common injury on OS

Ankle Anatomy

Ankle Anatomy

Ankle Fracture Lauge-Hansen Classification Pronation : abd, eversion, DF Supination : add, inversion, PF

Ankle Fracture Lauge-Hansen Classification Supination - External Rotation Supination Addution Pronation - External Rotation Pronation Addution 40-75%

Ankle Fracture Lauge-Hansen Classification Supination - External Rotation Supination Adduction Pronation - External Rotation Pronation Addution 10-20% (I) a low avulsion fracture of the lateral malleolus or lateral ligament injury; and (II) a vertical shear fracture of the medial malleolus (Fig. 3). This pattern is also associated with an impaction injury to the medial tibial plafond.6

Ankle Fracture Lauge-Hansen Classification Supination - External Rotation Supination Addution Pronation - External Rotation Pronation Addution 5-20%

Ankle Fracture Lauge-Hansen Classification Supination - External Rotation Supination Addution Pronation - External Rotation Pronation Addution 7-15%

SER type

Syndesmosis injury a joint in which the bones are united by fibrous connective tissue forming an interosseous membrane or ligament. A syndesmosis is slightly movable articulation where the contiguous bony surfaces are united by an interosseous ligament or membrane as in the inferior tibiofibular articulation

Hypothesis Bony attenuation vs Syndesmosis

Hypothesis Bony attenuation vs Syndesmosis

Patients Patents : ankle Fx. c OP in our hospital Inclusion Exclusion From Mar. 2006 to Feb. 2013 1109 cases Inclusion SER type Preoperative X-ray, 3D-CT Exclusion Direct injury, anatomical deformity Inadequate radiography

Measurement Method 3-Dimension CT X-ray (Mortise view)

Radiographic measurement Fracture height Fracture length Medial joint space Bony attenuation Age Gender Injury mechanism

Fracture height

Medial joint space

Fracture length

Bony attenuation (Lat. Malleolus)

Bony attenuation (Med. Malleolus)

Bony attenuation (Talus)

Ankle Mortise view

Fracture height leg internally rotated 15 to 20 deg so that x-ray beam is nearly perpendicular to the intermalleolar line.

Medial joint space

Statistical Method median, interquatile range(IQR) and proportions Kolmogogrov-Smirnov test Univariate analyses (Mann-Whitney U test or chi- square exact test) receiver operating characteristic (ROC) curve Delong’s test detect the significant of the area under the curve (AUC)

Result SER type ankle Fx. : total 191 patients Male : Female = 104 : 87 Mean age = 53.2±15.2 years (range 18-85) Syndesmotic injury (+) : 38 patients Syndesmotic injury (-) : 153 patients

Result : CT Fracture height Medial joint spaces Syndesmotic injury (+) : 13.89±17.36 Syndesmotic injury (- ) : -0.87±6.95 P-value < 0.001 Medial joint spaces Syndesmotic injury (+) : 5.58±3.48 Syndesmotic injury (- ) : 3.41 ±1.55

Result : CT Medial joint spaces Fracture length Syndesmotic injury (+) : 333.58±91.03 Syndesmotic injury (- ) : 244.67 ±94.69 P-value < 0.001 Fracture length Syndesmotic injury (+) : 37.45±13.57 Syndesmotic injury (- ) : 34.46 ±11.63 P-value =0.232

Result : CT AUC : 0.765 AUC값이 00이상으로 유의하게 나왔다

Result : CT AUC : 0.731

Result : CT AUC : 0.753

Result : CT Fracture height Medial joint spaces Syndesmotic injury (+) : 15.13 ±18.79 Syndesmotic injury (- ) : -1.28±7.22 P-value < 0.001 Medial joint spaces Syndesmotic injury (+) : 5.84±3.39 Syndesmotic injury (- ) : 3.34±1.49

Result : CT AUC : 0.569

Result : X-ray AUC : 0.779

Result : X-ray AUC : 0.726

Conclusion SER type Ankle Fx. X-ray CT frature height > 7mm Medial joint space > 4.5mm CT Fracture height > 3mm Medial joint space > 4.9mm Bony attenuation > 262.7

Conclusion Consideration of treatment on Ankle Fx. Predictive Factors of Syndesmotic injury

Thank you for your attention

Discussion X-ray, CT Limitation Factors to detect syndesmotic injury Retrospective study Technical problem in radiograph