Petra Margetić

Diagnostic value of US, MR and MR arthrography in shoulder instability.

INTRODUCTION The aim of our study was to compare US, conventional MRI and MR arthrography findings in patients with anterior shoulder instability and with a clinical diagnosis of labral capsular ligamentous complex lesion. At the same time we evaluated the accuracy of MR arthrography in the diagnosis of this lesion. METHODS After approval of the local Ethics Committee, our departments Trauma Registry from July 2008 up to February 2012 was retrospectively reviewed to identify all eligible patients. Eligibility criteria included: 1)history of acute or chronic shoulder instability (more than three dislocations over a period of more than two months); 2) diagnosis of labroligamentous lesion. All patients were investigated with plain radiographs, Ultrasound Scans (US), Magnetic Resonance Imaging (MRI) and MR arthrography. Finally, all patients underwent an arthroscopy that confirmed the diagnosis. RESULTS A total of 200 consecutive patients who met the inclusion criteria were included in this study. The mean age was 39 years (range 15 to 83); 147 were male and 133 involved the right shoulder. Chronic instability was documented in 133 patients, whereas acute instability was documented in 67 patients. We detected a statistically significant difference between US and MR arthrography in SLAP (Superior Labrum Anterior to Posterior) lesions (TypeII, III and IV), in Bankart lesions, in glenohumeral ligament lesions (superior, middle, anterior-inferior and anterior inferior glenohumeral ligament) in Hill-Sachs lesions, in diagnosing internal subacromial impingement and in normal findings. MR arthrography was superior to the US. A statistically significant difference was evident between MRI and MR arthrography findings in SLAP lesions (III and IV Type lesions), in glenohumeral ligament lesions (anterior inferior and posterior inferior glenohumeral ligament), in partial rotator cuff ruptures and in normal findings. MR arthrography diagnosed this lesion better than MRI without contrast. We also found a statistically significant difference between US and MRI findings in SLAP Type II lesions, in partial rotator cuff ruptures, in Hill-Sachs lesions and in diagnosing internal subacromial impingement. CONCLUSION The US scan is a valuable diagnostic technique for rotator cuff complete or incomplete ruptures. For evaluating Hill-Sachs lesions or bony Bankart lesions, MRI is more accurate. In the case of labral capsular ligamentous complex lesions, MR arthrography is superior.

Diagnosis of occult radial head and neck fracture in adults

The purpose of this study was to compare imaging modalities in the diagnosis of occult radial head and neck fractures and to assess the diagnostic value of ultrasound in diagnosing occult fractures of the radial head and neck. The study included 193 patients (101 male, 92 female) who were referred by trauma surgeons from January 2011 to July 2014 and presented with history of acute elbow trauma. The mean age of the patients was 37 years (range 15-82 years); 95 right and 98 left elbows were included in the study. Clinical examinations and standard radiograms were conducted. The anteroposterior radiographic view revealed no visible signs of fracture. The lateral radiographic view showed displacement of the anterior and posterior fat pads (fat pad sign) due to joint effusion, which is an indirect sign of fracture. In all 193 cases, ultrasound examination showed intraarticular effusion. In 176 cases (91%), there was effusion in both the olecranon bursa and the elbow joint. In 10 patients (5%), there was effusion only inside the elbow joint and in seven cases (4%) there was effusion only in the olecranon bursa. Cortical discontinuity (a direct sign of fracture) was clearly visualised in 157 cases (82%), in the radial neck in 108 cases and in the radial head in 49 cases. Ultrasound findings of fracture were questionable in 36 cases (18%). Step-off deformities, tiny avulsed bone fragments, double-line appearance of cortical margins, and diffuse irregularity of the bone surfaces were identified as auxiliary ultrasound findings (indirect signs of fracture). Standard radiograms were repeated after 7-10 days. In 184 cases (95%), there was a clearly visible fracture: a fracture of the radial neck in 111 cases (58%) and a fracture of non-displaced radial head in 73 cases (37%). In nine cases (5%), radial fracture was not confirmed on radiogram and MRI was performed in these patients. In conclusion, ultrasound imaging proved to be an effective method for diagnosing occult fractures of the radial head or neck when initial radiograms showed only intraarticular effusion. Ultrasound imaging is a cost-effective, easy-to-use and radiation-free method. For these reasons we recommend it for early detection of occult fracture in the emergency room.

L-S1.2b Operative treatment of the lesser arc wrist injuries

Introduction: These are high energy injuries in which an axial load is applied to a hyperextended and ulnarly deviated wrist, placing the volar structures under tension and dorsal structures under compression and shear. Lesser arc injuries are capsuloligamentous disruptions following four stages: (1) the scapholunate ligament, (2) the space of Poirer, (3) the UTCC and UL ligament, and (4) lunate dislocation. In radiographs we see a difference between lunate dislocation represented by the spilled tea cup and the perilunate dislocation which is represented as a disruption of the lines of Gilula. Materials and Methods: 37 patients are presented, 2 female and 35 male. All patients were operated using a surgical approach that was dorsal, volar or a combination of the two. Using intraoperative fluoroscopy, dislocation reduction and fixation was made with Kirschner wires. Transfixation pins are placed to protect the ligament repairs and to maintain anatomical carpal alignment. In all patients disrupted scapholunate and lunotriquetral ligaments were repaired. Results: Cast or splint was removed between 4 and 6 weeks when the patient was given an orthosis to promote range of motion. Pins were removed between 6 and 8 weeks. All patients returned to normal activities between 6 and 12 months. Conclusion: All lesser arc injuries, ligament injury and bone dislocation, need to be surgically attended to achieve satisfactory range of motion at the end of treatment.

L-S1.2a Operative treatment of the greater arc wrist injuries

Introduction: In these high energy injuries an axial load is applied to a hyperextended and ulnarly deviated wrist, placing the volar structures under tension and dorsal structures under compression and shear. Greater arc injuries involve fractures through the radial styloid, scaphoid, lunate, capitates, triquetrum and ulna, either solely or in combination with lunate or perilunate dislocation. The most often greater arc injury is the trans-scaphoid perilunate dislocation. In a TSPLD the scaphoid remains attached to the lunate with an intact scapholunate ligament. Materials and Methods: In these high energy injuries an axial load is applied to a hyperextended and ulnarly deviated wrist, placing the volar structures under tension and dorsal structures under compression and shear. Greater arc injuries involve fractures through the radial styloid, scaphoid, lunate, capitates, triquetrum and ulna, either solely or in combination with lunate or perilunate dislocation. The most often greater arc injury is the trans-scaphoid perilunate dislocation. In a TSPLD the scaphoid remains attached to the lunate with an intact scapholunate ligament. Results: Immobilization was removed 4 to 6 weeks when the patient was given an orthosis to promote range of motion. Pins were removed between 6 and 8 weeks. All patients returned to normal activities between 6 and 12 months. The average Mayo wrist score was 87 (65-99) which is good. All patients returned to their previous employment. Conclusion: All patients with greater arc injuries need surgical treatment, osteosynthesis, dislocation repositioning and lunotriquetral repair. Range of motion was excellent for patients operated on within 7 days of injury, good for patients operated between 7-45 days of injury. If treatment is delayed beyond 45 days the result of satisfactory range of motion is reduced.