Posterosuperior glenoid internal impingement of the shoulder in the overhead athlete: pathogenesis, clinical features and MR imaging findings.

Posterosuperior glenoid internal impingement (PGII) is an impingement syndrome of the shoulder that is most commonly seen in the throwing or overhead athlete. The supraspinatus can be normally compressed or impinged between the greater tuberosity and the posterosuperior labrum in the abduction and external rotation position. However, repetitive throwing and biomechanical abnormalities may lead to the intensification of this contact and to the clinical and pathological picture of PGII.

Are extra-labral MR findings useful in the diagnosis of a labral tear?

Objective: To determine diagnostic performance statistics of extra-labral magnetic resonance (MR) findings for detection of labral tears in a population of patients with clinical suspicion of this diagnosis.

Materials And Methods: Seventy-nine patients clinically suspected of having a labral tear (who underwent arthroscopy) had their MR studies retrospectively reviewed to determine the presence of lateral acetabular oedema-like marrow signal, ganglia, dysplastic femoral bumps, synovial herniation pits and geodes. These findings were then correlated with the arthroscopic presence (or absence) of a labral tear.

Muscle injury of the chest wall and upper extremity.

Most muscle trauma more commonly involves the lower extremity, but injury to the chest wall, particularly the pectoralis major, is well recognized. Trauma to the upper limb muscle-tendon unit is preserved. Development of complications from muscle injury is also discussed.

Prevalence and location of acetabular sublabral sulci at hip arthroscopy with retrospective MRI review.

Objective: The objective of this prospective study was to determine the prevalence and location of acetabular sublabral sulci diagnosed as variants at hip arthroscopy and to provide a retrospective MRI review.

Subjects And Methods: Two experienced hip arthroscopists noted the prevalence and location of acetabular labral sulci in 121 patients. The study population consisted of 57 males and 64 females with an average age of 43 years (range, 16-70 years).

MR imaging of post-traumatic articular cartilage injuries confined to the femoral trochlea. Arthroscopic correlation and clinical significance.

Objective: To assess and describe post-traumatic articular cartilage injuries isolated to the trochlear groove and provide insight into potential mechanism of injury.

Materials And Methods: We retrospectively evaluated MR imaging findings of all knee MRIs performed at our institution over the last 2 years (2450). Thirty patients met the criteria of a cartilage injury confined to the trochlear groove.

Use of the modified three-point Dixon technique in obtaining T1-weighted contrast-enhanced fat-saturated images on an open magnet.

The purpose of this study was to investigate the modified three-point Dixon technique as a method for obtaining fat-saturated T1-weighted sequences before and after intravenous gadolinium administration using an open MR imaging scanner. A preliminary experiment using an oil/gadolinium phantom was performed on a 0.35-T open magnet and an advanced 1.

Shoulder imaging in athletes.

Shoulder pain and injuries are common in athletes. Overhead athletes, in particular, place great demands on the shoulder and supporting structures. Magnetic resonance (MR) imaging is well suited to evaluation of the osseous structures and soft tissues of the shoulder and plays an important role in evaluation of shoulder pain in athletes.

Impingement syndrome of the ankle following supination external rotation trauma: MR imaging findings with arthroscopic correlation.

Our objective was to identify MR imaging findings in patients with syndesmotic soft tissue impingement of the ankle and to investigate the reliability of these imaging characteristics to predict syndesmotic soft tissue impingement syndromes of the ankle. Twenty-one ankles with chronic pain ultimately proven to have anterior soft tissue impingement syndrome were examined by MR imaging during January 1996 to June 2001. The MR imaging protocol included sagittal and coronal short tau inversion recovery (STIR), sagittal T1-weighted spin echo, axial and coronal proton-density, and T2-weighted spin-echo sequences.

Perthes lesion (a variant of the Bankart lesion): MR imaging and MR arthrographic findings with surgical correlation.

Objective: The aim of this study was to evaluate the use of MR imaging in the characterization of the Perthes lesion by correlating MR findings with findings at arthroscopy.

Conclusion: The use of a combination of axial and abduction-external rotation position sequences on MR images can be helpful in the diagnosis of a Perthes lesion. A fluid-filled joint with capsular distension, caused by either a large amount of effusion or MR arthrography, was found to be helpful in outlining Perthes lesions.