Impact of shoulder rotation on neck-shaft angle: A clinical study.

BACKGROUND: Two recent experimental studies evaluated the influence of shoulder rotation on neck-shaft angle, with conflicting results. However, there have been no clinical studies of whether this angle varies in different shoulder positions. The present study aimed to determine whether shoulder rotation affects neck-shaft angle on standard radiographs in patients with complaints of shoulder pain. HYPOTHESIS: Shoulder rotation does not affect neck-shaft angle. MATERIALS AND METHODS: A prospective study was conducted in selected patients with shoulder pain. Three true anterior-posterior radiographic views were obtained: in neutral rotation, 30° external rotation, and internal rotation with patient's arm in a sling. The X-rays were evaluated by three shoulder and elbow surgeons. Inter- and intra-observer reliability was evaluated by intraclass correlation coefficient (ICC). RESULTS: Neck-shaft angle on true AP view did not differ between neutral rotation and 30° external rotation: 132±6° and 130±9°, respectively (P>0.999). In internal rotation with the hand resting on the abdomen, neck-shaft angle was 145±6°: i.e., significantly different (P<0.001) to the other two positions. Intra- and inter-observer correlation demonstrated excellent reliability. CONCLUSIONS: Radiographic neck-shaft angle was significantly different in internal rotation with the patient's arm in a sling, compared with views in neutral or 30° external rotation. Intra- and inter-observer correlation showed excellent reliability. LEVEL OF EVIDENCE: II, comparative prospective study.

Osteoid osteoma of the glenoid: Arthroscopic treatment.

Osteoid osteoma is a benign tumor that is rarely found in the scapula. We report a clinical case involving a 36-year-old female patient who suffered from progressive pain in her right shoulder for 1 year. This patient was initially diagnosed with impingement syndrome and was treated unsuccessfully with medication and physical therapy for approximately 2 months. Based on imaging exams, a juxta-articular osteoid osteoma of the glenoid was identified. The patient underwent a shoulder arthroscopy that included tumor removal and treatment of the resulting chondral lesion. At 6-, 12- and 36-month assessments, the patient was asymptomatic, with a normal range of motion and experienced a pain intensity corresponding to 0 points on the Visual Analog Scale (VAS) and 35 points on the University of California, Los Angeles (UCLA) Scale. A postoperative MRI indicated the absence of any residual tumor tissue or inflammatory signs. We believe that the approach described in this paper allows juxta-articular osteoid osteomas to be accessed in a minimally invasive manner and permits not only adequate resection but also the treatment of chondral lesions that could remain after tumor resection.

Assessment of the function and resistance of sternoclavicular ligaments: A biomechanical study in cadavers.

BACKGROUND: Few biomechanical studies have assessed the resistance of the ligamentous structures of the sternoclavicular joint, and none have reproduced the physiological movements of the joint. Determining the structures that are injured in sternoclavicular dislocations is important for the surgical planning of acute or chronic ligament reconstruction. METHODS: Forty-eight joints from 24 human cadavers were studied, and they were divided into 4 groups of 12 joints each (retraction, protraction, depression and elevation). Biomechanical testing assessed primary and secondary failures. The mechanical resistance parameters between movements that occurred on the same plane (depression versus elevation, protraction versus retraction) were compared. RESULTS: The posterior sternoclavicular ligament was the most injured structure during the protraction test, but it was not injured during retraction. The anterior sternoclavicular ligament was the most affected structure during retraction and depression. The costoclavicular ligament was the most affected structure during elevation. Joint resistance was significantly greater during protraction movements when compared to retraction (P<0.05). CONCLUSION: The anterior sternoclavicular ligament was the most affected structure during retraction and depression movements. During protraction, lesions of the posterior sternoclavicular ligament were most frequent during elevation, and the costoclavicular ligament was the most frequently injured ligament. The resistance of the sternoclavicular joint was significantly greater during protraction movement when compared to retraction. LEVEL OF EVIDENCE: IV, basic science, biomechanics, cadaver model.