The value of ultrasonography in the preoperative diagnostic evaluation of patients with recurrent anterior shoulder dislocation: a prospective study of 44 patients.

The purpose of this study was to investigate the value of ultrasonography in the pre-operative assessment of patients with recurrent post-traumatic, anterior shoulder instability. Forty-four consecutive patients, 44 men and 12 women, with unilateral, post-traumatic, recurrent instability of the shoulder were included in the study. One experienced radiologist examined all patients, using a 5.0 or 7.5 MHz linear-array transducer, with the arm in different positions, one of which was used to provoke apprehension of the shoulder. Special attention was paid to the evaluation of the joint capsule, the anterior labrum, especially in terms of the presence of a Bankart lesion. All patients were subsequently treated surgically. After a diagnostic arthroscopy either an open or arthroscopic stabilisation of the shoulder was performed. Ultrasonography disclosed an unstable anterior labrum (equivalent to a Bankart lesion) in 36 shoulders; the lesion was verified in all 36 shoulders during arthroscopy. In three shoulders, arthroscopy disclosed an injured labrum, which had healed in an anterio-medial position on the scapular neck. In these three shoulders, ultrasonography failed to show any lesion. In five shoulders no Bankart lesion was found at arthroscopy. All these patients had increased shoulder laxity, and ultrasonography did not show any Bankart lesion. Furthermore a judgement of the joint capsule was not possible either. A bony Bankart lesion was found in four shoulders, using both arthroscopy and ultrasonography. The sensitivity of the ultrasonographic evaluation was 92%, and the specificity 100%. The positive predictive value was 100%, and the negative predictive value 63%. Ultrasonography showed a high correlation with the arthroscopic findings, with a high sensitivity and specificity. Therefore, we conclude that US can give important pre-operative information in patients with recurrent, unilateral, post-traumatic, anterior shoulder instability.

Back pain and degenerative abnormalities in the spine of young elite divers: a 5-year follow-up magnetic resonance imaging study.

Several studies have been published on disc degeneration among young athletes in sports with great demands on the back, but few on competitive divers; however, there are no long-term follow-up studies. Twenty elite divers between 10 and 21 years of age, with the highest possible national ranking, were selected at random without knowledge of previous or present back injuries or symptoms for an MRI study of the thoraco-lumbar spine in a 5-year longitudinal study. The occurrence of MRI abnormalities and their correlation with back pain were evaluated. Eighty-nine percent of the divers had a history of back pain and the median age at the first episode of back pain was 15 years. Sixty-five percent of the divers had MRI abnormalities in the thoraco-lumbar spine already at baseline. Only one diver without abnormalities at baseline had developed abnormalities at follow-up. Deterioration of any type of abnormality was found in 9 of 17 (53%) divers. Including all disc levels in all divers, the total number of abnormalities increased by 29% at follow-up, as compared to baseline. The most common abnormalities were reduced disc signal, Schmorl's nodes, and disc height reduction. Since almost all divers had previous or present back pain, a differentiated analysis of the relationship between pain and MRI findings was not possible. However, the high frequency of both back pain and MRI changes suggests a causal relationship. In conclusion, elite divers had high frequency of back pain at young ages and they run a high risk of developing degenerative abnormalities of the thoraco-lumbar spine, probably due to injuries to the spine during the growth spurt.

Fracture patterns of the adolescent porcine spine: an experimental loading study in bending-compression.

STUDY DESIGN: To expose functional spinal units from adolescent porcine to mechanical flexion-compression and extension-compression to failure. The biomechanical, radiologic, magnetic resonance imaging, and histologic characteristics are described. OBJECTIVES: The aim of the present study was to investigate the fracture pattern of functional spinal units from adolescent porcine lumbar spines in in vitro compression loading and bending. SUMMARY OF BACKGROUND DATA: In several studies, it has been shown that the adolescent spine, especially the vertebral growth zones, is vulnerable to trauma. A high frequency of abnormalities affecting the spine has been found among athletes participating in sports with high demands on the back. The etiology of these abnormalities is still a controversial issue. METHODS: Sixteen functional spinal units obtained from eight adolescent male pigs were used. Eight functional spinal units were exposed to flexion-compression and eight functional spinal units to extension-compression loading to failure. They were examined with plain radiography and magnetic resonance imaging before and after the loading. The functional spinal units were finally examined macroscopically and histologically. RESULTS: Fractures/separations were seen in the growth zone anteriorly and more frequently, posteriorly in functional spinal units exposed to flexion-compression. In the extension-compression group, such injuries occurred only anteriorly. Only large fractures could be seen on plain radiographs and on magnetic resonance imaging. Macroscopically, a fracture/separation could be seen in 15 cases and histologically in all 16 cases. The median angle at failure for the flexion group was 17 degrees (range, 12-19) and for the extension group 17 degrees (range, 13-19 degrees). The median ultimate compression load in the flexion-compression group was 1894 N (range, 1607-3138 N) and in the extension-compression group 1801 N (range, 1158-2368 N). CONCLUSIONS: The weakest part of the growing porcine lumbar spine, when compressed into flexion- or extension-compression, was the growth zone. The injury was more extensive in extension loading than during flexion loading. Growth zone injuries of the adolescent spine may go undetected on plain radiographs and magnetic resonance imaging.